// SPDX-License-Identifier: GPL-2.0-only
/*
 * GPMC support functions
 *
 * Copyright (C) 2005-2006 Nokia Corporation
 *
 * Author: Juha Yrjola
 *
 * Copyright (C) 2009 Texas Instruments
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 */
#include <linux/cleanup.h>
#include <linux/cpu_pm.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h> /* GPIO descriptor enum */
#include <linux/gpio/machine.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/omap-gpmc.h>
#include <linux/pm_runtime.h>
#include <linux/sizes.h>

#include <linux/platform_data/mtd-nand-omap2.h>

#define DEVICE_NAME             "omap-gpmc"

/* GPMC register offsets */
#define GPMC_REVISION           0x00
#define GPMC_SYSCONFIG          0x10
#define GPMC_SYSSTATUS          0x14
#define GPMC_IRQSTATUS          0x18
#define GPMC_IRQENABLE          0x1c
#define GPMC_TIMEOUT_CONTROL    0x40
#define GPMC_ERR_ADDRESS        0x44
#define GPMC_ERR_TYPE           0x48
#define GPMC_CONFIG             0x50
#define GPMC_STATUS             0x54
#define GPMC_PREFETCH_CONFIG1   0x1e0
#define GPMC_PREFETCH_CONFIG2   0x1e4
#define GPMC_PREFETCH_CONTROL   0x1ec
#define GPMC_PREFETCH_STATUS    0x1f0
#define GPMC_ECC_CONFIG         0x1f4
#define GPMC_ECC_CONTROL        0x1f8
#define GPMC_ECC_SIZE_CONFIG    0x1fc
#define GPMC_ECC1_RESULT        0x200
#define GPMC_ECC_BCH_RESULT_0   0x240   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_1   0x244   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_2   0x248   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_3   0x24c   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_4   0x300   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_5   0x304   /* not available on OMAP2 */
#define GPMC_ECC_BCH_RESULT_6   0x308   /* not available on OMAP2 */

/* GPMC ECC control settings */
#define GPMC_ECC_CTRL_ECCCLEAR          0x100
#define GPMC_ECC_CTRL_ECCDISABLE        0x000
#define GPMC_ECC_CTRL_ECCREG1           0x001
#define GPMC_ECC_CTRL_ECCREG2           0x002
#define GPMC_ECC_CTRL_ECCREG3           0x003
#define GPMC_ECC_CTRL_ECCREG4           0x004
#define GPMC_ECC_CTRL_ECCREG5           0x005
#define GPMC_ECC_CTRL_ECCREG6           0x006
#define GPMC_ECC_CTRL_ECCREG7           0x007
#define GPMC_ECC_CTRL_ECCREG8           0x008
#define GPMC_ECC_CTRL_ECCREG9           0x009

#define GPMC_CONFIG_LIMITEDADDRESS              BIT(1)

#define GPMC_STATUS_EMPTYWRITEBUFFERSTATUS      BIT(0)

#define GPMC_CONFIG2_CSEXTRADELAY               BIT(7)
#define GPMC_CONFIG3_ADVEXTRADELAY              BIT(7)
#define GPMC_CONFIG4_OEEXTRADELAY               BIT(7)
#define GPMC_CONFIG4_WEEXTRADELAY               BIT(23)
#define GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN        BIT(6)
#define GPMC_CONFIG6_CYCLE2CYCLESAMECSEN        BIT(7)

#define GPMC_CS0_OFFSET         0x60
#define GPMC_CS_SIZE            0x30
#define GPMC_BCH_SIZE           0x10

/*
 * The first 1MB of GPMC address space is typically mapped to
 * the internal ROM. Never allocate the first page, to
 * facilitate bug detection; even if we didn't boot from ROM.
 * As GPMC minimum partition size is 16MB we can only start from
 * there.
 */
#define GPMC_MEM_START          0x1000000
#define GPMC_MEM_END            0x3FFFFFFF

#define GPMC_CHUNK_SHIFT        24              /* 16 MB */
#define GPMC_SECTION_SHIFT      28              /* 128 MB */

#define CS_NUM_SHIFT            24
#define ENABLE_PREFETCH         (0x1 << 7)
#define DMA_MPU_MODE            2

#define GPMC_REVISION_MAJOR(l)          (((l) >> 4) & 0xf)
#define GPMC_REVISION_MINOR(l)          ((l) & 0xf)

#define GPMC_HAS_WR_ACCESS              0x1
#define GPMC_HAS_WR_DATA_MUX_BUS        0x2
#define GPMC_HAS_MUX_AAD                0x4

#define GPMC_NR_WAITPINS                4

#define GPMC_CS_CONFIG1         0x00
#define GPMC_CS_CONFIG2         0x04
#define GPMC_CS_CONFIG3         0x08
#define GPMC_CS_CONFIG4         0x0c
#define GPMC_CS_CONFIG5         0x10
#define GPMC_CS_CONFIG6         0x14
#define GPMC_CS_CONFIG7         0x18
#define GPMC_CS_NAND_COMMAND    0x1c
#define GPMC_CS_NAND_ADDRESS    0x20
#define GPMC_CS_NAND_DATA       0x24

/* Control Commands */
#define GPMC_CONFIG_RDY_BSY     0x00000001
#define GPMC_CONFIG_DEV_SIZE    0x00000002
#define GPMC_CONFIG_DEV_TYPE    0x00000003

#define GPMC_CONFIG_WAITPINPOLARITY(pin)        (BIT(pin) << 8)
#define GPMC_CONFIG1_WRAPBURST_SUPP     (1 << 31)
#define GPMC_CONFIG1_READMULTIPLE_SUPP  (1 << 30)
#define GPMC_CONFIG1_READTYPE_ASYNC     (0 << 29)
#define GPMC_CONFIG1_READTYPE_SYNC      (1 << 29)
#define GPMC_CONFIG1_WRITEMULTIPLE_SUPP (1 << 28)
#define GPMC_CONFIG1_WRITETYPE_ASYNC    (0 << 27)
#define GPMC_CONFIG1_WRITETYPE_SYNC     (1 << 27)
#define GPMC_CONFIG1_CLKACTIVATIONTIME(val) (((val) & 3) << 25)
/** CLKACTIVATIONTIME Max Ticks */
#define GPMC_CONFIG1_CLKACTIVATIONTIME_MAX 2
#define GPMC_CONFIG1_PAGE_LEN(val)      (((val) & 3) << 23)
/** ATTACHEDDEVICEPAGELENGTH Max Value */
#define GPMC_CONFIG1_ATTACHEDDEVICEPAGELENGTH_MAX 2
#define GPMC_CONFIG1_WAIT_READ_MON      (1 << 22)
#define GPMC_CONFIG1_WAIT_WRITE_MON     (1 << 21)
#define GPMC_CONFIG1_WAIT_MON_TIME(val) (((val) & 3) << 18)
/** WAITMONITORINGTIME Max Ticks */
#define GPMC_CONFIG1_WAITMONITORINGTIME_MAX  2
#define GPMC_CONFIG1_WAIT_PIN_SEL(val)  (((val) & 3) << 16)
#define GPMC_CONFIG1_DEVICESIZE(val)    (((val) & 3) << 12)
#define GPMC_CONFIG1_DEVICESIZE_16      GPMC_CONFIG1_DEVICESIZE(1)
/** DEVICESIZE Max Value */
#define GPMC_CONFIG1_DEVICESIZE_MAX     1
#define GPMC_CONFIG1_DEVICETYPE(val)    (((val) & 3) << 10)
#define GPMC_CONFIG1_DEVICETYPE_NOR     GPMC_CONFIG1_DEVICETYPE(0)
#define GPMC_CONFIG1_MUXTYPE(val)       (((val) & 3) << 8)
#define GPMC_CONFIG1_TIME_PARA_GRAN     (1 << 4)
#define GPMC_CONFIG1_FCLK_DIV(val)      ((val) & 3)
#define GPMC_CONFIG1_FCLK_DIV2          (GPMC_CONFIG1_FCLK_DIV(1))
#define GPMC_CONFIG1_FCLK_DIV3          (GPMC_CONFIG1_FCLK_DIV(2))
#define GPMC_CONFIG1_FCLK_DIV4          (GPMC_CONFIG1_FCLK_DIV(3))
#define GPMC_CONFIG7_CSVALID            (1 << 6)

#define GPMC_CONFIG7_BASEADDRESS_MASK   0x3f
#define GPMC_CONFIG7_CSVALID_MASK       BIT(6)
#define GPMC_CONFIG7_MASKADDRESS_OFFSET 8
#define GPMC_CONFIG7_MASKADDRESS_MASK   (0xf << GPMC_CONFIG7_MASKADDRESS_OFFSET)
/* All CONFIG7 bits except reserved bits */
#define GPMC_CONFIG7_MASK               (GPMC_CONFIG7_BASEADDRESS_MASK | \
                                         GPMC_CONFIG7_CSVALID_MASK |     \
                                         GPMC_CONFIG7_MASKADDRESS_MASK)

#define GPMC_DEVICETYPE_NOR             0
#define GPMC_DEVICETYPE_NAND            2
#define GPMC_CONFIG_WRITEPROTECT        0x00000010
#define WR_RD_PIN_MONITORING            0x00600000

/* ECC commands */
#define GPMC_ECC_READ           0 /* Reset Hardware ECC for read */
#define GPMC_ECC_WRITE          1 /* Reset Hardware ECC for write */
#define GPMC_ECC_READSYN        2 /* Reset before syndrom is read back */

#define GPMC_NR_NAND_IRQS       2 /* number of NAND specific IRQs */

enum gpmc_clk_domain {
        GPMC_CD_FCLK,
        GPMC_CD_CLK
};

struct gpmc_cs_data {
        const char *name;

#define GPMC_CS_RESERVED        (1 << 0)
        u32 flags;

        struct resource mem;
};

/* Structure to save gpmc cs context */
struct gpmc_cs_config {
        u32 config1;
        u32 config2;
        u32 config3;
        u32 config4;
        u32 config5;
        u32 config6;
        u32 config7;
        int is_valid;
};

/*
 * Structure to save/restore gpmc context
 * to support core off on OMAP3
 */
struct omap3_gpmc_regs {
        u32 sysconfig;
        u32 irqenable;
        u32 timeout_ctrl;
        u32 config;
        u32 prefetch_config1;
        u32 prefetch_config2;
        u32 prefetch_control;
        struct gpmc_cs_config cs_context[GPMC_CS_NUM];
};

struct gpmc_waitpin {
        u32 pin;
        u32 polarity;
        struct gpio_desc *desc;
};

struct gpmc_device {
        struct device *dev;
        int irq;
        struct irq_chip irq_chip;
        struct gpio_chip gpio_chip;
        struct notifier_block nb;
        struct omap3_gpmc_regs context;
        struct gpmc_waitpin *waitpins;
        int nirqs;
        unsigned int is_suspended:1;
        struct resource *data;
};

static struct irq_domain *gpmc_irq_domain;

static struct resource  gpmc_mem_root;
static struct gpmc_cs_data gpmc_cs[GPMC_CS_NUM];
static DEFINE_SPINLOCK(gpmc_mem_lock);
/* Define chip-selects as reserved by default until probe completes */
static unsigned int gpmc_cs_num = GPMC_CS_NUM;
static unsigned int gpmc_nr_waitpins;
static unsigned int gpmc_capability;
static void __iomem *gpmc_base;

static struct clk *gpmc_l3_clk;

static irqreturn_t gpmc_handle_irq(int irq, void *dev);

static void gpmc_write_reg(int idx, u32 val)
{
        writel_relaxed(val, gpmc_base + idx);
}

static u32 gpmc_read_reg(int idx)
{
        return readl_relaxed(gpmc_base + idx);
}

void gpmc_cs_write_reg(int cs, int idx, u32 val)
{
        void __iomem *reg_addr;

        reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
        writel_relaxed(val, reg_addr);
}

static u32 gpmc_cs_read_reg(int cs, int idx)
{
        void __iomem *reg_addr;

        reg_addr = gpmc_base + GPMC_CS0_OFFSET + (cs * GPMC_CS_SIZE) + idx;
        return readl_relaxed(reg_addr);
}

/* TODO: Add support for gpmc_fck to clock framework and use it */
static unsigned long gpmc_get_fclk_period(void)
{
        unsigned long rate = clk_get_rate(gpmc_l3_clk);

        rate /= 1000;
        rate = 1000000000 / rate;       /* In picoseconds */

        return rate;
}

/**
 * gpmc_get_clk_period - get period of selected clock domain in ps
 * @cs: Chip Select Region.
 * @cd: Clock Domain.
 *
 * GPMC_CS_CONFIG1 GPMCFCLKDIVIDER for cs has to be setup
 * prior to calling this function with GPMC_CD_CLK.
 */
static unsigned long gpmc_get_clk_period(int cs, enum gpmc_clk_domain cd)
{
        unsigned long tick_ps = gpmc_get_fclk_period();
        u32 l;
        int div;

        switch (cd) {
        case GPMC_CD_CLK:
                /* get current clk divider */
                l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
                div = (l & 0x03) + 1;
                /* get GPMC_CLK period */
                tick_ps *= div;
                break;
        case GPMC_CD_FCLK:
        default:
                break;
        }

        return tick_ps;
}

static unsigned int gpmc_ns_to_clk_ticks(unsigned int time_ns, int cs,
                                         enum gpmc_clk_domain cd)
{
        unsigned long tick_ps;

        /* Calculate in picosecs to yield more exact results */
        tick_ps = gpmc_get_clk_period(cs, cd);

        return (time_ns * 1000 + tick_ps - 1) / tick_ps;
}

static unsigned int gpmc_ns_to_ticks(unsigned int time_ns)
{
        return gpmc_ns_to_clk_ticks(time_ns, /* any CS */ 0, GPMC_CD_FCLK);
}

static unsigned int gpmc_ps_to_ticks(unsigned int time_ps)
{
        unsigned long tick_ps;

        /* Calculate in picosecs to yield more exact results */
        tick_ps = gpmc_get_fclk_period();

        return (time_ps + tick_ps - 1) / tick_ps;
}

static unsigned int gpmc_ticks_to_ps(unsigned int ticks)
{
        return ticks * gpmc_get_fclk_period();
}

static unsigned int gpmc_round_ps_to_ticks(unsigned int time_ps)
{
        unsigned long ticks = gpmc_ps_to_ticks(time_ps);

        return ticks * gpmc_get_fclk_period();
}

static inline void gpmc_cs_modify_reg(int cs, int reg, u32 mask, bool value)
{
        u32 l;

        l = gpmc_cs_read_reg(cs, reg);
        if (value)
                l |= mask;
        else
                l &= ~mask;
        gpmc_cs_write_reg(cs, reg, l);
}

static void gpmc_cs_bool_timings(int cs, const struct gpmc_bool_timings *p)
{
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG1,
                           GPMC_CONFIG1_TIME_PARA_GRAN,
                           p->time_para_granularity);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG2,
                           GPMC_CONFIG2_CSEXTRADELAY, p->cs_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG3,
                           GPMC_CONFIG3_ADVEXTRADELAY, p->adv_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG4,
                           GPMC_CONFIG4_OEEXTRADELAY, p->oe_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG4,
                           GPMC_CONFIG4_WEEXTRADELAY, p->we_extra_delay);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG6,
                           GPMC_CONFIG6_CYCLE2CYCLESAMECSEN,
                           p->cycle2cyclesamecsen);
        gpmc_cs_modify_reg(cs, GPMC_CS_CONFIG6,
                           GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN,
                           p->cycle2cyclediffcsen);
}

#ifdef CONFIG_OMAP_GPMC_DEBUG

static unsigned int gpmc_clk_ticks_to_ns(unsigned int ticks, int cs,
                                         enum gpmc_clk_domain cd)
{
        return ticks * gpmc_get_clk_period(cs, cd) / 1000;
}

/**
 * get_gpmc_timing_reg - read a timing parameter and print DTS settings for it.
 * @cs:      Chip Select Region
 * @reg:     GPMC_CS_CONFIGn register offset.
 * @st_bit:  Start Bit
 * @end_bit: End Bit. Must be >= @st_bit.
 * @max:     Maximum parameter value (before optional @shift).
 *           If 0, maximum is as high as @st_bit and @end_bit allow.
 * @name:    DTS node name, w/o "gpmc,"
 * @cd:      Clock Domain of timing parameter.
 * @shift:   Parameter value left shifts @shift, which is then printed instead of value.
 * @raw:     Raw Format Option.
 *           raw format:  gpmc,name = <value>
 *           tick format: gpmc,name = <value> /&zwj;* x ns -- y ns; x ticks *&zwj;/
 *           Where x ns -- y ns result in the same tick value.
 *           When @max is exceeded, "invalid" is printed inside comment.
 * @noval:   Parameter values equal to 0 are not printed.
 * @return:  Specified timing parameter (after optional @shift).
 *
 */
static int get_gpmc_timing_reg(
        /* timing specifiers */
        int cs, int reg, int st_bit, int end_bit, int max,
        const char *name, const enum gpmc_clk_domain cd,
        /* value transform */
        int shift,
        /* format specifiers */
        bool raw, bool noval)
{
        u32 l;
        int nr_bits;
        int mask;
        bool invalid;

        l = gpmc_cs_read_reg(cs, reg);
        nr_bits = end_bit - st_bit + 1;
        mask = (1 << nr_bits) - 1;
        l = (l >> st_bit) & mask;
        if (!max)
                max = mask;
        invalid = l > max;
        if (shift)
                l = (shift << l);
        if (noval && (l == 0))
                return 0;
        if (!raw) {
                /* DTS tick format for timings in ns */
                unsigned int time_ns;
                unsigned int time_ns_min = 0;

                if (l)
                        time_ns_min = gpmc_clk_ticks_to_ns(l - 1, cs, cd) + 1;
                time_ns = gpmc_clk_ticks_to_ns(l, cs, cd);
                pr_info("gpmc,%s = <%u>; /* %u ns - %u ns; %i ticks%s*/\n",
                        name, time_ns, time_ns_min, time_ns, l,
                        invalid ? "; invalid " : " ");
        } else {
                /* raw format */
                pr_info("gpmc,%s = <%u>;%s\n", name, l,
                        invalid ? " /* invalid */" : "");
        }

        return l;
}

#define GPMC_PRINT_CONFIG(cs, config) \
        pr_info("cs%i %s: 0x%08x\n", cs, #config, \
                gpmc_cs_read_reg(cs, config))
#define GPMC_GET_RAW(reg, st, end, field) \
        get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, GPMC_CD_FCLK, 0, 1, 0)
#define GPMC_GET_RAW_MAX(reg, st, end, max, field) \
        get_gpmc_timing_reg(cs, (reg), (st), (end), (max), field, GPMC_CD_FCLK, 0, 1, 0)
#define GPMC_GET_RAW_BOOL(reg, st, end, field) \
        get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, GPMC_CD_FCLK, 0, 1, 1)
#define GPMC_GET_RAW_SHIFT_MAX(reg, st, end, shift, max, field) \
        get_gpmc_timing_reg(cs, (reg), (st), (end), (max), field, GPMC_CD_FCLK, (shift), 1, 1)
#define GPMC_GET_TICKS(reg, st, end, field) \
        get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, GPMC_CD_FCLK, 0, 0, 0)
#define GPMC_GET_TICKS_CD(reg, st, end, field, cd) \
        get_gpmc_timing_reg(cs, (reg), (st), (end), 0, field, (cd), 0, 0, 0)
#define GPMC_GET_TICKS_CD_MAX(reg, st, end, max, field, cd) \
        get_gpmc_timing_reg(cs, (reg), (st), (end), (max), field, (cd), 0, 0, 0)

static void gpmc_show_regs(int cs, const char *desc)
{
        pr_info("gpmc cs%i %s:\n", cs, desc);
        GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG1);
        GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG2);
        GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG3);
        GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG4);
        GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG5);
        GPMC_PRINT_CONFIG(cs, GPMC_CS_CONFIG6);
}

/*
 * Note that gpmc,wait-pin handing wrongly assumes bit 8 is available,
 * see commit c9fb809.
 */
static void gpmc_cs_show_timings(int cs, const char *desc)
{
        gpmc_show_regs(cs, desc);

        pr_info("gpmc cs%i access configuration:\n", cs);
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1,  4,  4, "time-para-granularity");
        GPMC_GET_RAW(GPMC_CS_CONFIG1,  8,  9, "mux-add-data");
        GPMC_GET_RAW_SHIFT_MAX(GPMC_CS_CONFIG1, 12, 13, 1,
                               GPMC_CONFIG1_DEVICESIZE_MAX, "device-width");
        GPMC_GET_RAW(GPMC_CS_CONFIG1, 16, 17, "wait-pin");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 21, 21, "wait-on-write");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 22, 22, "wait-on-read");
        GPMC_GET_RAW_SHIFT_MAX(GPMC_CS_CONFIG1, 23, 24, 4,
                               GPMC_CONFIG1_ATTACHEDDEVICEPAGELENGTH_MAX,
                               "burst-length");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 27, 27, "sync-write");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 28, 28, "burst-write");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 29, 29, "gpmc,sync-read");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 30, 30, "burst-read");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG1, 31, 31, "burst-wrap");

        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG2,  7,  7, "cs-extra-delay");

        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG3,  7,  7, "adv-extra-delay");

        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4, 23, 23, "we-extra-delay");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG4,  7,  7, "oe-extra-delay");

        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  7,  7, "cycle2cycle-samecsen");
        GPMC_GET_RAW_BOOL(GPMC_CS_CONFIG6,  6,  6, "cycle2cycle-diffcsen");

        pr_info("gpmc cs%i timings configuration:\n", cs);
        GPMC_GET_TICKS(GPMC_CS_CONFIG2,  0,  3, "cs-on-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG2,  8, 12, "cs-rd-off-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG2, 16, 20, "cs-wr-off-ns");

        GPMC_GET_TICKS(GPMC_CS_CONFIG3,  0,  3, "adv-on-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG3,  8, 12, "adv-rd-off-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG3, 16, 20, "adv-wr-off-ns");
        if (gpmc_capability & GPMC_HAS_MUX_AAD) {
                GPMC_GET_TICKS(GPMC_CS_CONFIG3, 4, 6, "adv-aad-mux-on-ns");
                GPMC_GET_TICKS(GPMC_CS_CONFIG3, 24, 26,
                                "adv-aad-mux-rd-off-ns");
                GPMC_GET_TICKS(GPMC_CS_CONFIG3, 28, 30,
                                "adv-aad-mux-wr-off-ns");
        }

        GPMC_GET_TICKS(GPMC_CS_CONFIG4,  0,  3, "oe-on-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG4,  8, 12, "oe-off-ns");
        if (gpmc_capability & GPMC_HAS_MUX_AAD) {
                GPMC_GET_TICKS(GPMC_CS_CONFIG4,  4,  6, "oe-aad-mux-on-ns");
                GPMC_GET_TICKS(GPMC_CS_CONFIG4, 13, 15, "oe-aad-mux-off-ns");
        }
        GPMC_GET_TICKS(GPMC_CS_CONFIG4, 16, 19, "we-on-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG4, 24, 28, "we-off-ns");

        GPMC_GET_TICKS(GPMC_CS_CONFIG5,  0,  4, "rd-cycle-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG5,  8, 12, "wr-cycle-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG5, 16, 20, "access-ns");

        GPMC_GET_TICKS(GPMC_CS_CONFIG5, 24, 27, "page-burst-access-ns");

        GPMC_GET_TICKS(GPMC_CS_CONFIG6, 0, 3, "bus-turnaround-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG6, 8, 11, "cycle2cycle-delay-ns");

        GPMC_GET_TICKS_CD_MAX(GPMC_CS_CONFIG1, 18, 19,
                              GPMC_CONFIG1_WAITMONITORINGTIME_MAX,
                              "wait-monitoring-ns", GPMC_CD_CLK);
        GPMC_GET_TICKS_CD_MAX(GPMC_CS_CONFIG1, 25, 26,
                              GPMC_CONFIG1_CLKACTIVATIONTIME_MAX,
                              "clk-activation-ns", GPMC_CD_FCLK);

        GPMC_GET_TICKS(GPMC_CS_CONFIG6, 16, 19, "wr-data-mux-bus-ns");
        GPMC_GET_TICKS(GPMC_CS_CONFIG6, 24, 28, "wr-access-ns");
}
#else
static inline void gpmc_cs_show_timings(int cs, const char *desc)
{
}
#endif

/**
 * set_gpmc_timing_reg - set a single timing parameter for Chip Select Region.
 * Caller is expected to have initialized CONFIG1 GPMCFCLKDIVIDER
 * prior to calling this function with @cd equal to GPMC_CD_CLK.
 *
 * @cs:      Chip Select Region.
 * @reg:     GPMC_CS_CONFIGn register offset.
 * @st_bit:  Start Bit
 * @end_bit: End Bit. Must be >= @st_bit.
 * @max:     Maximum parameter value.
 *           If 0, maximum is as high as @st_bit and @end_bit allow.
 * @time:    Timing parameter in ns.
 * @cd:      Timing parameter clock domain.
 * @name:    Timing parameter name.
 * @return:  0 on success, -1 on error.
 */
static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, int max,
                               int time, enum gpmc_clk_domain cd, const char *name)
{
        u32 l;
        int ticks, mask, nr_bits;

        if (time == 0)
                ticks = 0;
        else
                ticks = gpmc_ns_to_clk_ticks(time, cs, cd);
        nr_bits = end_bit - st_bit + 1;
        mask = (1 << nr_bits) - 1;

        if (!max)
                max = mask;

        if (ticks > max) {
                pr_err("%s: GPMC CS%d: %s %d ns, %d ticks > %d ticks\n",
                       __func__, cs, name, time, ticks, max);

                return -1;
        }

        l = gpmc_cs_read_reg(cs, reg);
#ifdef CONFIG_OMAP_GPMC_DEBUG
        pr_info("GPMC CS%d: %-17s: %3d ticks, %3lu ns (was %3i ticks) %3d ns\n",
                cs, name, ticks, gpmc_get_clk_period(cs, cd) * ticks / 1000,
                        (l >> st_bit) & mask, time);
#endif
        l &= ~(mask << st_bit);
        l |= ticks << st_bit;
        gpmc_cs_write_reg(cs, reg, l);

        return 0;
}

/**
 * gpmc_calc_waitmonitoring_divider - calculate proper GPMCFCLKDIVIDER based on WAITMONITORINGTIME
 * WAITMONITORINGTIME will be _at least_ as long as desired, i.e.
 * read  --> don't sample bus too early
 * write --> data is longer on bus
 *
 * Formula:
 * gpmc_clk_div + 1 = ceil(ceil(waitmonitoringtime_ns / gpmc_fclk_ns)
 *                    / waitmonitoring_ticks)
 * WAITMONITORINGTIME resulting in 0 or 1 tick with div = 1 are caught by
 * div <= 0 check.
 *
 * @wait_monitoring: WAITMONITORINGTIME in ns.
 * @return:          -1 on failure to scale, else proper divider > 0.
 */
static int gpmc_calc_waitmonitoring_divider(unsigned int wait_monitoring)
{
        int div = gpmc_ns_to_ticks(wait_monitoring);

        div += GPMC_CONFIG1_WAITMONITORINGTIME_MAX - 1;
        div /= GPMC_CONFIG1_WAITMONITORINGTIME_MAX;

        if (div > 4)
                return -1;
        if (div <= 0)
                div = 1;

        return div;
}

/**
 * gpmc_calc_divider - calculate GPMC_FCLK divider for sync_clk GPMC_CLK period.
 * @sync_clk: GPMC_CLK period in ps.
 * @return:   Returns at least 1 if GPMC_FCLK can be divided to GPMC_CLK.
 *            Else, returns -1.
 */
int gpmc_calc_divider(unsigned int sync_clk)
{
        int div = gpmc_ps_to_ticks(sync_clk);

        if (div > 4)
                return -1;
        if (div <= 0)
                div = 1;

        return div;
}

/**
 * gpmc_cs_set_timings - program timing parameters for Chip Select Region.
 * @cs:     Chip Select Region.
 * @t:      GPMC timing parameters.
 * @s:      GPMC timing settings.
 * @return: 0 on success, -1 on error.
 */
int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t,
                        const struct gpmc_settings *s)
{
        int div, ret;
        u32 l;

        div = gpmc_calc_divider(t->sync_clk);
        if (div < 0)
                return -EINVAL;

        /*
         * See if we need to change the divider for waitmonitoringtime.
         *
         * Calculate GPMCFCLKDIVIDER independent of gpmc,sync-clk-ps in DT for
         * pure asynchronous accesses, i.e. both read and write asynchronous.
         * However, only do so if WAITMONITORINGTIME is actually used, i.e.
         * either WAITREADMONITORING or WAITWRITEMONITORING is set.
         *
         * This statement must not change div to scale async WAITMONITORINGTIME
         * to protect mixed synchronous and asynchronous accesses.
         *
         * We raise an error later if WAITMONITORINGTIME does not fit.
         */
        if (!s->sync_read && !s->sync_write &&
            (s->wait_on_read || s->wait_on_write)
           ) {
                div = gpmc_calc_waitmonitoring_divider(t->wait_monitoring);
                if (div < 0) {
                        pr_err("%s: waitmonitoringtime %3d ns too large for greatest gpmcfclkdivider.\n",
                               __func__,
                               t->wait_monitoring
                               );
                        return -ENXIO;
                }
        }

        ret = 0;
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 0, 3, 0, t->cs_on,
                                   GPMC_CD_FCLK, "cs_on");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 8, 12, 0, t->cs_rd_off,
                                   GPMC_CD_FCLK, "cs_rd_off");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 16, 20, 0, t->cs_wr_off,
                                   GPMC_CD_FCLK, "cs_wr_off");
        if (ret)
                return -ENXIO;

        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 0, 3, 0, t->adv_on,
                                   GPMC_CD_FCLK, "adv_on");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 8, 12, 0, t->adv_rd_off,
                                   GPMC_CD_FCLK, "adv_rd_off");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 16, 20, 0, t->adv_wr_off,
                                   GPMC_CD_FCLK, "adv_wr_off");
        if (ret)
                return -ENXIO;

        if (gpmc_capability & GPMC_HAS_MUX_AAD) {
                ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 4, 6, 0,
                                           t->adv_aad_mux_on, GPMC_CD_FCLK,
                                           "adv_aad_mux_on");
                ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 24, 26, 0,
                                           t->adv_aad_mux_rd_off, GPMC_CD_FCLK,
                                           "adv_aad_mux_rd_off");
                ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG3, 28, 30, 0,
                                           t->adv_aad_mux_wr_off, GPMC_CD_FCLK,
                                           "adv_aad_mux_wr_off");
                if (ret)
                        return -ENXIO;
        }

        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 0, 3, 0, t->oe_on,
                                   GPMC_CD_FCLK, "oe_on");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 8, 12, 0, t->oe_off,
                                   GPMC_CD_FCLK, "oe_off");
        if (gpmc_capability & GPMC_HAS_MUX_AAD) {
                ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 4, 6, 0,
                                           t->oe_aad_mux_on, GPMC_CD_FCLK,
                                           "oe_aad_mux_on");
                ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 13, 15, 0,
                                           t->oe_aad_mux_off, GPMC_CD_FCLK,
                                           "oe_aad_mux_off");
        }
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 16, 19, 0, t->we_on,
                                   GPMC_CD_FCLK, "we_on");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG4, 24, 28, 0, t->we_off,
                                   GPMC_CD_FCLK, "we_off");
        if (ret)
                return -ENXIO;

        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 0, 4, 0, t->rd_cycle,
                                   GPMC_CD_FCLK, "rd_cycle");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 8, 12, 0, t->wr_cycle,
                                   GPMC_CD_FCLK, "wr_cycle");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 16, 20, 0, t->access,
                                   GPMC_CD_FCLK, "access");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG5, 24, 27, 0,
                                   t->page_burst_access, GPMC_CD_FCLK,
                                   "page_burst_access");
        if (ret)
                return -ENXIO;

        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 0, 3, 0,
                                   t->bus_turnaround, GPMC_CD_FCLK,
                                   "bus_turnaround");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 8, 11, 0,
                                   t->cycle2cycle_delay, GPMC_CD_FCLK,
                                   "cycle2cycle_delay");
        if (ret)
                return -ENXIO;

        if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS) {
                ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 16, 19, 0,
                                           t->wr_data_mux_bus, GPMC_CD_FCLK,
                                           "wr_data_mux_bus");
                if (ret)
                        return -ENXIO;
        }
        if (gpmc_capability & GPMC_HAS_WR_ACCESS) {
                ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG6, 24, 28, 0,
                                           t->wr_access, GPMC_CD_FCLK,
                                           "wr_access");
                if (ret)
                        return -ENXIO;
        }

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
        l &= ~0x03;
        l |= (div - 1);
        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l);

        ret = 0;
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG1, 18, 19,
                                   GPMC_CONFIG1_WAITMONITORINGTIME_MAX,
                                   t->wait_monitoring, GPMC_CD_CLK,
                                   "wait_monitoring");
        ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG1, 25, 26,
                                   GPMC_CONFIG1_CLKACTIVATIONTIME_MAX,
                                   t->clk_activation, GPMC_CD_FCLK,
                                   "clk_activation");
        if (ret)
                return -ENXIO;

#ifdef CONFIG_OMAP_GPMC_DEBUG
        pr_info("GPMC CS%d CLK period is %lu ns (div %d)\n",
                        cs, (div * gpmc_get_fclk_period()) / 1000, div);
#endif

        gpmc_cs_bool_timings(cs, &t->bool_timings);
        gpmc_cs_show_timings(cs, "after gpmc_cs_set_timings");

        return 0;
}

static int gpmc_cs_set_memconf(int cs, u32 base, u32 size)
{
        u32 l;
        u32 mask;

        /*
         * Ensure that base address is aligned on a
         * boundary equal to or greater than size.
         */
        if (base & (size - 1))
                return -EINVAL;

        base >>= GPMC_CHUNK_SHIFT;
        mask = (1 << GPMC_SECTION_SHIFT) - size;
        mask >>= GPMC_CHUNK_SHIFT;
        mask <<= GPMC_CONFIG7_MASKADDRESS_OFFSET;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        l &= ~GPMC_CONFIG7_MASK;
        l |= base & GPMC_CONFIG7_BASEADDRESS_MASK;
        l |= mask & GPMC_CONFIG7_MASKADDRESS_MASK;
        l |= GPMC_CONFIG7_CSVALID;
        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);

        return 0;
}

static void gpmc_cs_enable_mem(int cs)
{
        u32 l;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        l |= GPMC_CONFIG7_CSVALID;
        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
}

static void gpmc_cs_disable_mem(int cs)
{
        u32 l;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        l &= ~GPMC_CONFIG7_CSVALID;
        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
}

static void gpmc_cs_get_memconf(int cs, u32 *base, u32 *size)
{
        u32 l;
        u32 mask;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        *base = (l & 0x3f) << GPMC_CHUNK_SHIFT;
        mask = (l >> 8) & 0x0f;
        *size = (1 << GPMC_SECTION_SHIFT) - (mask << GPMC_CHUNK_SHIFT);
}

static int gpmc_cs_mem_enabled(int cs)
{
        u32 l;

        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
        return l & GPMC_CONFIG7_CSVALID;
}

static void gpmc_cs_set_reserved(int cs, int reserved)
{
        struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

        gpmc->flags |= GPMC_CS_RESERVED;
}

static bool gpmc_cs_reserved(int cs)
{
        struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

        return gpmc->flags & GPMC_CS_RESERVED;
}

static unsigned long gpmc_mem_align(unsigned long size)
{
        int order;

        size = (size - 1) >> (GPMC_CHUNK_SHIFT - 1);
        order = GPMC_CHUNK_SHIFT - 1;
        do {
                size >>= 1;
                order++;
        } while (size);
        size = 1 << order;
        return size;
}

static int gpmc_cs_insert_mem(int cs, unsigned long base, unsigned long size)
{
        struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
        struct resource *res = &gpmc->mem;
        int r;

        size = gpmc_mem_align(size);
        spin_lock(&gpmc_mem_lock);
        res->start = base;
        res->end = base + size - 1;
        r = request_resource(&gpmc_mem_root, res);
        spin_unlock(&gpmc_mem_lock);

        return r;
}

static int gpmc_cs_delete_mem(int cs)
{
        struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
        struct resource *res = &gpmc->mem;
        int r;

        spin_lock(&gpmc_mem_lock);
        r = release_resource(res);
        res->start = 0;
        res->end = 0;
        spin_unlock(&gpmc_mem_lock);

        return r;
}

int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
{
        struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
        struct resource *res = &gpmc->mem;
        int r = -1;

        if (cs >= gpmc_cs_num) {
                pr_err("%s: requested chip-select is disabled\n", __func__);
                return -ENODEV;
        }
        size = gpmc_mem_align(size);
        if (size > (1 << GPMC_SECTION_SHIFT))
                return -ENOMEM;

        guard(spinlock)(&gpmc_mem_lock);

        if (gpmc_cs_reserved(cs))
                return -EBUSY;

        if (gpmc_cs_mem_enabled(cs))
                r = adjust_resource(res, res->start & ~(size - 1), size);
        if (r < 0)
                r = allocate_resource(&gpmc_mem_root, res, size, 0, ~0,
                                      size, NULL, NULL);
        if (r < 0)
                return r;

        /* Disable CS while changing base address and size mask */
        gpmc_cs_disable_mem(cs);

        r = gpmc_cs_set_memconf(cs, res->start, resource_size(res));
        if (r < 0) {
                release_resource(res);
                return r;
        }

        /* Enable CS */
        gpmc_cs_enable_mem(cs);
        *base = res->start;
        gpmc_cs_set_reserved(cs, 1);

        return 0;
}
EXPORT_SYMBOL(gpmc_cs_request);

void gpmc_cs_free(int cs)
{
        struct gpmc_cs_data *gpmc;
        struct resource *res;

        guard(spinlock)(&gpmc_mem_lock);
        if (cs >= gpmc_cs_num || cs < 0 || !gpmc_cs_reserved(cs)) {
                WARN(1, "Trying to free non-reserved GPMC CS%d\n", cs);
                return;
        }
        gpmc = &gpmc_cs[cs];
        res = &gpmc->mem;

        gpmc_cs_disable_mem(cs);
        if (res->flags)
                release_resource(res);
        gpmc_cs_set_reserved(cs, 0);
}
EXPORT_SYMBOL(gpmc_cs_free);

static bool gpmc_is_valid_waitpin(u32 waitpin)
{
        return waitpin < gpmc_nr_waitpins;
}

static int gpmc_alloc_waitpin(struct gpmc_device *gpmc,
                              struct gpmc_settings *p)
{
        int ret;
        struct gpmc_waitpin *waitpin;
        struct gpio_desc *waitpin_desc;

        if (!gpmc_is_valid_waitpin(p->wait_pin))
                return -EINVAL;

        waitpin = &gpmc->waitpins[p->wait_pin];

        if (!waitpin->desc) {
                /* Reserve the GPIO for wait pin usage.
                 * GPIO polarity doesn't matter here. Wait pin polarity
                 * is set in GPMC_CONFIG register.
                 */
                waitpin_desc = gpiochip_request_own_desc(&gpmc->gpio_chip,
                                                         p->wait_pin, "WAITPIN",
                                                         GPIO_ACTIVE_HIGH,
                                                         GPIOD_IN);

                ret = PTR_ERR(waitpin_desc);
                if (IS_ERR(waitpin_desc) && ret != -EBUSY)
                        return ret;

                /* New wait pin */
                waitpin->desc = waitpin_desc;
                waitpin->pin = p->wait_pin;
                waitpin->polarity = p->wait_pin_polarity;
        } else {
                /* Shared wait pin */
                if (p->wait_pin_polarity != waitpin->polarity ||
                    p->wait_pin != waitpin->pin) {
                        dev_err(gpmc->dev,
                                "shared-wait-pin: invalid configuration\n");
                        return -EINVAL;
                }
                dev_info(gpmc->dev, "shared wait-pin: %d\n", waitpin->pin);
        }

        return 0;
}

static void gpmc_free_waitpin(struct gpmc_device *gpmc,
                              int wait_pin)
{
        if (gpmc_is_valid_waitpin(wait_pin))
                gpiochip_free_own_desc(gpmc->waitpins[wait_pin].desc);
}

/**
 * gpmc_configure - write request to configure gpmc
 * @cmd: command type
 * @wval: value to write
 * @return status of the operation
 */
int gpmc_configure(int cmd, int wval)
{
        u32 regval;

        switch (cmd) {
        case GPMC_CONFIG_WP:
                regval = gpmc_read_reg(GPMC_CONFIG);
                if (wval)
                        regval &= ~GPMC_CONFIG_WRITEPROTECT; /* WP is ON */
                else
                        regval |= GPMC_CONFIG_WRITEPROTECT;  /* WP is OFF */
                gpmc_write_reg(GPMC_CONFIG, regval);
                break;

        default:
                pr_err("%s: command not supported\n", __func__);
                return -EINVAL;
        }

        return 0;
}
EXPORT_SYMBOL(gpmc_configure);

static bool gpmc_nand_writebuffer_empty(void)
{
        if (gpmc_read_reg(GPMC_STATUS) & GPMC_STATUS_EMPTYWRITEBUFFERSTATUS)
                return true;

        return false;
}

static struct gpmc_nand_ops nand_ops = {
        .nand_writebuffer_empty = gpmc_nand_writebuffer_empty,
};

/**
 * gpmc_omap_get_nand_ops - Get the GPMC NAND interface
 * @reg: the GPMC NAND register map exclusive for NAND use.
 * @cs: GPMC chip select number on which the NAND sits. The
 *      register map returned will be specific to this chip select.
 *
 * Returns NULL on error e.g. invalid cs.
 */
struct gpmc_nand_ops *gpmc_omap_get_nand_ops(struct gpmc_nand_regs *reg, int cs)
{
        int i;

        if (cs >= gpmc_cs_num)
                return NULL;

        reg->gpmc_nand_command = gpmc_base + GPMC_CS0_OFFSET +
                                GPMC_CS_NAND_COMMAND + GPMC_CS_SIZE * cs;
        reg->gpmc_nand_address = gpmc_base + GPMC_CS0_OFFSET +
                                GPMC_CS_NAND_ADDRESS + GPMC_CS_SIZE * cs;
        reg->gpmc_nand_data = gpmc_base + GPMC_CS0_OFFSET +
                                GPMC_CS_NAND_DATA + GPMC_CS_SIZE * cs;
        reg->gpmc_prefetch_config1 = gpmc_base + GPMC_PREFETCH_CONFIG1;
        reg->gpmc_prefetch_config2 = gpmc_base + GPMC_PREFETCH_CONFIG2;
        reg->gpmc_prefetch_control = gpmc_base + GPMC_PREFETCH_CONTROL;
        reg->gpmc_prefetch_status = gpmc_base + GPMC_PREFETCH_STATUS;
        reg->gpmc_ecc_config = gpmc_base + GPMC_ECC_CONFIG;
        reg->gpmc_ecc_control = gpmc_base + GPMC_ECC_CONTROL;
        reg->gpmc_ecc_size_config = gpmc_base + GPMC_ECC_SIZE_CONFIG;
        reg->gpmc_ecc1_result = gpmc_base + GPMC_ECC1_RESULT;

        for (i = 0; i < GPMC_BCH_NUM_REMAINDER; i++) {
                reg->gpmc_bch_result0[i] = gpmc_base + GPMC_ECC_BCH_RESULT_0 +
                                           GPMC_BCH_SIZE * i;
                reg->gpmc_bch_result1[i] = gpmc_base + GPMC_ECC_BCH_RESULT_1 +
                                           GPMC_BCH_SIZE * i;
                reg->gpmc_bch_result2[i] = gpmc_base + GPMC_ECC_BCH_RESULT_2 +
                                           GPMC_BCH_SIZE * i;
                reg->gpmc_bch_result3[i] = gpmc_base + GPMC_ECC_BCH_RESULT_3 +
                                           GPMC_BCH_SIZE * i;
                reg->gpmc_bch_result4[i] = gpmc_base + GPMC_ECC_BCH_RESULT_4 +
                                           i * GPMC_BCH_SIZE;
                reg->gpmc_bch_result5[i] = gpmc_base + GPMC_ECC_BCH_RESULT_5 +
                                           i * GPMC_BCH_SIZE;
                reg->gpmc_bch_result6[i] = gpmc_base + GPMC_ECC_BCH_RESULT_6 +
                                           i * GPMC_BCH_SIZE;
        }

        return &nand_ops;
}
EXPORT_SYMBOL_GPL(gpmc_omap_get_nand_ops);

static void gpmc_omap_onenand_calc_sync_timings(struct gpmc_timings *t,
                                                struct gpmc_settings *s,
                                                int freq, int latency)
{
        struct gpmc_device_timings dev_t;
        const int t_cer  = 15;
        const int t_avdp = 12;
        const int t_cez  = 20; /* max of t_cez, t_oez */
        const int t_wpl  = 40;
        const int t_wph  = 30;
        int min_gpmc_clk_period, t_ces, t_avds, t_avdh, t_ach, t_aavdh, t_rdyo;

        switch (freq) {
        case 104:
                min_gpmc_clk_period = 9600; /* 104 MHz */
                t_ces   = 3;
                t_avds  = 4;
                t_avdh  = 2;
                t_ach   = 3;
                t_aavdh = 6;
                t_rdyo  = 6;
                break;
        case 83:
                min_gpmc_clk_period = 12000; /* 83 MHz */
                t_ces   = 5;
                t_avds  = 4;
                t_avdh  = 2;
                t_ach   = 6;
                t_aavdh = 6;
                t_rdyo  = 9;
                break;
        case 66:
                min_gpmc_clk_period = 15000; /* 66 MHz */
                t_ces   = 6;
                t_avds  = 5;
                t_avdh  = 2;
                t_ach   = 6;
                t_aavdh = 6;
                t_rdyo  = 11;
                break;
        default:
                min_gpmc_clk_period = 18500; /* 54 MHz */
                t_ces   = 7;
                t_avds  = 7;
                t_avdh  = 7;
                t_ach   = 9;
                t_aavdh = 7;
                t_rdyo  = 15;
                break;
        }

        /* Set synchronous read timings */
        memset(&dev_t, 0, sizeof(dev_t));

        if (!s->sync_write) {
                dev_t.t_avdp_w = max(t_avdp, t_cer) * 1000;
                dev_t.t_wpl = t_wpl * 1000;
                dev_t.t_wph = t_wph * 1000;
                dev_t.t_aavdh = t_aavdh * 1000;
        }
        dev_t.ce_xdelay = true;
        dev_t.avd_xdelay = true;
        dev_t.oe_xdelay = true;
        dev_t.we_xdelay = true;
        dev_t.clk = min_gpmc_clk_period;
        dev_t.t_bacc = dev_t.clk;
        dev_t.t_ces = t_ces * 1000;
        dev_t.t_avds = t_avds * 1000;
        dev_t.t_avdh = t_avdh * 1000;
        dev_t.t_ach = t_ach * 1000;
        dev_t.cyc_iaa = (latency + 1);
        dev_t.t_cez_r = t_cez * 1000;
        dev_t.t_cez_w = dev_t.t_cez_r;
        dev_t.cyc_aavdh_oe = 1;
        dev_t.t_rdyo = t_rdyo * 1000 + min_gpmc_clk_period;

        gpmc_calc_timings(t, s, &dev_t);
}

int gpmc_omap_onenand_set_timings(struct device *dev, int cs, int freq,
                                  int latency,
                                  struct gpmc_onenand_info *info)
{
        int ret;
        struct gpmc_timings gpmc_t;
        struct gpmc_settings gpmc_s;

        gpmc_read_settings_dt(dev->of_node, &gpmc_s);

        info->sync_read = gpmc_s.sync_read;
        info->sync_write = gpmc_s.sync_write;
        info->burst_len = gpmc_s.burst_len;

        if (!gpmc_s.sync_read && !gpmc_s.sync_write)
                return 0;

        gpmc_omap_onenand_calc_sync_timings(&gpmc_t, &gpmc_s, freq, latency);

        ret = gpmc_cs_program_settings(cs, &gpmc_s);
        if (ret < 0)
                return ret;

        return gpmc_cs_set_timings(cs, &gpmc_t, &gpmc_s);
}
EXPORT_SYMBOL_GPL(gpmc_omap_onenand_set_timings);

static int gpmc_irq_endis(unsigned long hwirq, bool endis)
{
        u32 regval;

        /* bits GPMC_NR_NAND_IRQS to 8 are reserved */
        if (hwirq >= GPMC_NR_NAND_IRQS)
                hwirq += 8 - GPMC_NR_NAND_IRQS;

        regval = gpmc_read_reg(GPMC_IRQENABLE);
        if (endis)
                regval |= BIT(hwirq);
        else
                regval &= ~BIT(hwirq);
        gpmc_write_reg(GPMC_IRQENABLE, regval);

        return 0;
}

static void gpmc_irq_disable(struct irq_data *p)
{
        gpmc_irq_endis(p->hwirq, false);
}

static void gpmc_irq_enable(struct irq_data *p)
{
        gpmc_irq_endis(p->hwirq, true);
}

static void gpmc_irq_mask(struct irq_data *d)
{
        gpmc_irq_endis(d->hwirq, false);
}

static void gpmc_irq_unmask(struct irq_data *d)
{
        gpmc_irq_endis(d->hwirq, true);
}

static void gpmc_irq_edge_config(unsigned long hwirq, bool rising_edge)
{
        u32 regval;

        /* NAND IRQs polarity is not configurable */
        if (hwirq < GPMC_NR_NAND_IRQS)
                return;

        /* WAITPIN starts at BIT 8 */
        hwirq += 8 - GPMC_NR_NAND_IRQS;

        regval = gpmc_read_reg(GPMC_CONFIG);
        if (rising_edge)
                regval &= ~BIT(hwirq);
        else
                regval |= BIT(hwirq);

        gpmc_write_reg(GPMC_CONFIG, regval);
}

static void gpmc_irq_ack(struct irq_data *d)
{
        unsigned int hwirq = d->hwirq;

        /* skip reserved bits */
        if (hwirq >= GPMC_NR_NAND_IRQS)
                hwirq += 8 - GPMC_NR_NAND_IRQS;

        /* Setting bit to 1 clears (or Acks) the interrupt */
        gpmc_write_reg(GPMC_IRQSTATUS, BIT(hwirq));
}

static int gpmc_irq_set_type(struct irq_data *d, unsigned int trigger)
{
        /* can't set type for NAND IRQs */
        if (d->hwirq < GPMC_NR_NAND_IRQS)
                return -EINVAL;

        /* We can support either rising or falling edge at a time */
        if (trigger == IRQ_TYPE_EDGE_FALLING)
                gpmc_irq_edge_config(d->hwirq, false);
        else if (trigger == IRQ_TYPE_EDGE_RISING)
                gpmc_irq_edge_config(d->hwirq, true);
        else
                return -EINVAL;

        return 0;
}

static int gpmc_irq_map(struct irq_domain *d, unsigned int virq,
                        irq_hw_number_t hw)
{
        struct gpmc_device *gpmc = d->host_data;

        irq_set_chip_data(virq, gpmc);
        if (hw < GPMC_NR_NAND_IRQS) {
                irq_modify_status(virq, IRQ_NOREQUEST, IRQ_NOAUTOEN);
                irq_set_chip_and_handler(virq, &gpmc->irq_chip,
                                         handle_simple_irq);
        } else {
                irq_set_chip_and_handler(virq, &gpmc->irq_chip,
                                         handle_edge_irq);
        }

        return 0;
}

static const struct irq_domain_ops gpmc_irq_domain_ops = {
        .map    = gpmc_irq_map,
        .xlate  = irq_domain_xlate_twocell,
};

static irqreturn_t gpmc_handle_irq(int irq, void *data)
{
        int hwirq, virq;
        u32 regval, regvalx;
        struct gpmc_device *gpmc = data;

        regval = gpmc_read_reg(GPMC_IRQSTATUS);
        regvalx = regval;

        if (!regval)
                return IRQ_NONE;

        for (hwirq = 0; hwirq < gpmc->nirqs; hwirq++) {
                /* skip reserved status bits */
                if (hwirq == GPMC_NR_NAND_IRQS)
                        regvalx >>= 8 - GPMC_NR_NAND_IRQS;

                if (regvalx & BIT(hwirq)) {
                        virq = irq_find_mapping(gpmc_irq_domain, hwirq);
                        if (!virq) {
                                dev_warn(gpmc->dev,
                                         "spurious irq detected hwirq %d, virq %d\n",
                                         hwirq, virq);
                        }

                        generic_handle_irq(virq);
                }
        }

        gpmc_write_reg(GPMC_IRQSTATUS, regval);

        return IRQ_HANDLED;
}

static int gpmc_setup_irq(struct gpmc_device *gpmc)
{
        u32 regval;
        int rc;

        /* Disable interrupts */
        gpmc_write_reg(GPMC_IRQENABLE, 0);

        /* clear interrupts */
        regval = gpmc_read_reg(GPMC_IRQSTATUS);
        gpmc_write_reg(GPMC_IRQSTATUS, regval);

        gpmc->irq_chip.name = "gpmc";
        gpmc->irq_chip.irq_enable = gpmc_irq_enable;
        gpmc->irq_chip.irq_disable = gpmc_irq_disable;
        gpmc->irq_chip.irq_ack = gpmc_irq_ack;
        gpmc->irq_chip.irq_mask = gpmc_irq_mask;
        gpmc->irq_chip.irq_unmask = gpmc_irq_unmask;
        gpmc->irq_chip.irq_set_type = gpmc_irq_set_type;

        gpmc_irq_domain = irq_domain_create_linear(dev_fwnode(gpmc->dev), gpmc->nirqs,
                                                   &gpmc_irq_domain_ops, gpmc);
        if (!gpmc_irq_domain) {
                dev_err(gpmc->dev, "IRQ domain add failed\n");
                return -ENODEV;
        }

        rc = request_irq(gpmc->irq, gpmc_handle_irq, 0, "gpmc", gpmc);
        if (rc) {
                dev_err(gpmc->dev, "failed to request irq %d: %d\n",
                        gpmc->irq, rc);
                irq_domain_remove(gpmc_irq_domain);
                gpmc_irq_domain = NULL;
        }

        return rc;
}

static int gpmc_free_irq(struct gpmc_device *gpmc)
{
        int hwirq;

        free_irq(gpmc->irq, gpmc);

        for (hwirq = 0; hwirq < gpmc->nirqs; hwirq++)
                irq_dispose_mapping(irq_find_mapping(gpmc_irq_domain, hwirq));

        irq_domain_remove(gpmc_irq_domain);
        gpmc_irq_domain = NULL;

        return 0;
}

static void gpmc_mem_exit(void)
{
        int cs;

        for (cs = 0; cs < gpmc_cs_num; cs++) {
                if (!gpmc_cs_mem_enabled(cs))
                        continue;
                gpmc_cs_delete_mem(cs);
        }
}

static void gpmc_mem_init(struct gpmc_device *gpmc)
{
        int cs;

        if (!gpmc->data) {
                /* All legacy devices have same data IO window */
                gpmc_mem_root.start = GPMC_MEM_START;
                gpmc_mem_root.end = GPMC_MEM_END;
        } else {
                gpmc_mem_root.start = gpmc->data->start;
                gpmc_mem_root.end = gpmc->data->end;
        }

        /* Reserve all regions that has been set up by bootloader */
        for (cs = 0; cs < gpmc_cs_num; cs++) {
                u32 base, size;

                if (!gpmc_cs_mem_enabled(cs))
                        continue;
                gpmc_cs_get_memconf(cs, &base, &size);
                if (gpmc_cs_insert_mem(cs, base, size)) {
                        pr_warn("%s: disabling cs %d mapped at 0x%x-0x%x\n",
                                __func__, cs, base, base + size);
                        gpmc_cs_disable_mem(cs);
                }
        }
}

static u32 gpmc_round_ps_to_sync_clk(u32 time_ps, u32 sync_clk)
{
        u32 temp;
        int div;

        div = gpmc_calc_divider(sync_clk);
        temp = gpmc_ps_to_ticks(time_ps);
        temp = (temp + div - 1) / div;
        return gpmc_ticks_to_ps(temp * div);
}

/* XXX: can the cycles be avoided ? */
static int gpmc_calc_sync_read_timings(struct gpmc_timings *gpmc_t,
                                       struct gpmc_device_timings *dev_t,
                                       bool mux)
{
        u32 temp;

        /* adv_rd_off */
        temp = dev_t->t_avdp_r;
        /* XXX: mux check required ? */
        if (mux) {
                /* XXX: t_avdp not to be required for sync, only added for tusb
                 * this indirectly necessitates requirement of t_avdp_r and
                 * t_avdp_w instead of having a single t_avdp
                 */
                temp = max_t(u32, temp, gpmc_t->clk_activation + dev_t->t_avdh);
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        }
        gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp);

        /* oe_on */
        temp = dev_t->t_oeasu; /* XXX: remove this ? */
        if (mux) {
                temp = max_t(u32, temp, gpmc_t->clk_activation + dev_t->t_ach);
                temp = max_t(u32, temp, gpmc_t->adv_rd_off +
                                gpmc_ticks_to_ps(dev_t->cyc_aavdh_oe));
        }
        gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp);

        /* access */
        /* XXX: any scope for improvement ?, by combining oe_on
         * and clk_activation, need to check whether
         * access = clk_activation + round to sync clk ?
         */
        temp = max_t(u32, dev_t->t_iaa, dev_t->cyc_iaa * gpmc_t->sync_clk);
        temp += gpmc_t->clk_activation;
        if (dev_t->cyc_oe)
                temp = max_t(u32, temp, gpmc_t->oe_on +
                                gpmc_ticks_to_ps(dev_t->cyc_oe));
        gpmc_t->access = gpmc_round_ps_to_ticks(temp);

        gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1);
        gpmc_t->cs_rd_off = gpmc_t->oe_off;

        /* rd_cycle */
        temp = max_t(u32, dev_t->t_cez_r, dev_t->t_oez);
        temp = gpmc_round_ps_to_sync_clk(temp, gpmc_t->sync_clk) +
                                                        gpmc_t->access;
        /* XXX: barter t_ce_rdyz with t_cez_r ? */
        if (dev_t->t_ce_rdyz)
                temp = max_t(u32, temp, gpmc_t->cs_rd_off + dev_t->t_ce_rdyz);
        gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_sync_write_timings(struct gpmc_timings *gpmc_t,
                                        struct gpmc_device_timings *dev_t,
                                        bool mux)
{
        u32 temp;

        /* adv_wr_off */
        temp = dev_t->t_avdp_w;
        if (mux) {
                temp = max_t(u32, temp,
                        gpmc_t->clk_activation + dev_t->t_avdh);
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        }
        gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp);

        /* wr_data_mux_bus */
        temp = max_t(u32, dev_t->t_weasu,
                        gpmc_t->clk_activation + dev_t->t_rdyo);
        /* XXX: shouldn't mux be kept as a whole for wr_data_mux_bus ?,
         * and in that case remember to handle we_on properly
         */
        if (mux) {
                temp = max_t(u32, temp,
                        gpmc_t->adv_wr_off + dev_t->t_aavdh);
                temp = max_t(u32, temp, gpmc_t->adv_wr_off +
                                gpmc_ticks_to_ps(dev_t->cyc_aavdh_we));
        }
        gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp);

        /* we_on */
        if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
                gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu);
        else
                gpmc_t->we_on = gpmc_t->wr_data_mux_bus;

        /* wr_access */
        /* XXX: gpmc_capability check reqd ? , even if not, will not harm */
        gpmc_t->wr_access = gpmc_t->access;

        /* we_off */
        temp = gpmc_t->we_on + dev_t->t_wpl;
        temp = max_t(u32, temp,
                        gpmc_t->wr_access + gpmc_ticks_to_ps(1));
        temp = max_t(u32, temp,
                gpmc_t->we_on + gpmc_ticks_to_ps(dev_t->cyc_wpl));
        gpmc_t->we_off = gpmc_round_ps_to_ticks(temp);

        gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off +
                                                        dev_t->t_wph);

        /* wr_cycle */
        temp = gpmc_round_ps_to_sync_clk(dev_t->t_cez_w, gpmc_t->sync_clk);
        temp += gpmc_t->wr_access;
        /* XXX: barter t_ce_rdyz with t_cez_w ? */
        if (dev_t->t_ce_rdyz)
                temp = max_t(u32, temp,
                                 gpmc_t->cs_wr_off + dev_t->t_ce_rdyz);
        gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_async_read_timings(struct gpmc_timings *gpmc_t,
                                        struct gpmc_device_timings *dev_t,
                                        bool mux)
{
        u32 temp;

        /* adv_rd_off */
        temp = dev_t->t_avdp_r;
        if (mux)
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        gpmc_t->adv_rd_off = gpmc_round_ps_to_ticks(temp);

        /* oe_on */
        temp = dev_t->t_oeasu;
        if (mux)
                temp = max_t(u32, temp, gpmc_t->adv_rd_off + dev_t->t_aavdh);
        gpmc_t->oe_on = gpmc_round_ps_to_ticks(temp);

        /* access */
        temp = max_t(u32, dev_t->t_iaa, /* XXX: remove t_iaa in async ? */
                     gpmc_t->oe_on + dev_t->t_oe);
        temp = max_t(u32, temp, gpmc_t->cs_on + dev_t->t_ce);
        temp = max_t(u32, temp, gpmc_t->adv_on + dev_t->t_aa);
        gpmc_t->access = gpmc_round_ps_to_ticks(temp);

        gpmc_t->oe_off = gpmc_t->access + gpmc_ticks_to_ps(1);
        gpmc_t->cs_rd_off = gpmc_t->oe_off;

        /* rd_cycle */
        temp = max_t(u32, dev_t->t_rd_cycle,
                        gpmc_t->cs_rd_off + dev_t->t_cez_r);
        temp = max_t(u32, temp, gpmc_t->oe_off + dev_t->t_oez);
        gpmc_t->rd_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_async_write_timings(struct gpmc_timings *gpmc_t,
                                         struct gpmc_device_timings *dev_t,
                                         bool mux)
{
        u32 temp;

        /* adv_wr_off */
        temp = dev_t->t_avdp_w;
        if (mux)
                temp = max_t(u32, gpmc_t->adv_on + gpmc_ticks_to_ps(1), temp);
        gpmc_t->adv_wr_off = gpmc_round_ps_to_ticks(temp);

        /* wr_data_mux_bus */
        temp = dev_t->t_weasu;
        if (mux) {
                temp = max_t(u32, temp, gpmc_t->adv_wr_off + dev_t->t_aavdh);
                temp = max_t(u32, temp, gpmc_t->adv_wr_off +
                                gpmc_ticks_to_ps(dev_t->cyc_aavdh_we));
        }
        gpmc_t->wr_data_mux_bus = gpmc_round_ps_to_ticks(temp);

        /* we_on */
        if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS)
                gpmc_t->we_on = gpmc_round_ps_to_ticks(dev_t->t_weasu);
        else
                gpmc_t->we_on = gpmc_t->wr_data_mux_bus;

        /* we_off */
        temp = gpmc_t->we_on + dev_t->t_wpl;
        gpmc_t->we_off = gpmc_round_ps_to_ticks(temp);

        gpmc_t->cs_wr_off = gpmc_round_ps_to_ticks(gpmc_t->we_off +
                                                        dev_t->t_wph);

        /* wr_cycle */
        temp = max_t(u32, dev_t->t_wr_cycle,
                                gpmc_t->cs_wr_off + dev_t->t_cez_w);
        gpmc_t->wr_cycle = gpmc_round_ps_to_ticks(temp);

        return 0;
}

static int gpmc_calc_sync_common_timings(struct gpmc_timings *gpmc_t,
                        struct gpmc_device_timings *dev_t)
{
        u32 temp;

        gpmc_t->sync_clk = gpmc_calc_divider(dev_t->clk) *
                                                gpmc_get_fclk_period();

        gpmc_t->page_burst_access = gpmc_round_ps_to_sync_clk(
                                        dev_t->t_bacc,
                                        gpmc_t->sync_clk);

        temp = max_t(u32, dev_t->t_ces, dev_t->t_avds);
        gpmc_t->clk_activation = gpmc_round_ps_to_ticks(temp);

        if (gpmc_calc_divider(gpmc_t->sync_clk) != 1)
                return 0;

        if (dev_t->ce_xdelay)
                gpmc_t->bool_timings.cs_extra_delay = true;
        if (dev_t->avd_xdelay)
                gpmc_t->bool_timings.adv_extra_delay = true;
        if (dev_t->oe_xdelay)
                gpmc_t->bool_timings.oe_extra_delay = true;
        if (dev_t->we_xdelay)
                gpmc_t->bool_timings.we_extra_delay = true;

        return 0;
}

static int gpmc_calc_common_timings(struct gpmc_timings *gpmc_t,
                                    struct gpmc_device_timings *dev_t,
                                    bool sync)
{
        u32 temp;

        /* cs_on */
        gpmc_t->cs_on = gpmc_round_ps_to_ticks(dev_t->t_ceasu);

        /* adv_on */
        temp = dev_t->t_avdasu;
        if (dev_t->t_ce_avd)
                temp = max_t(u32, temp,
                                gpmc_t->cs_on + dev_t->t_ce_avd);
        gpmc_t->adv_on = gpmc_round_ps_to_ticks(temp);

        if (sync)
                gpmc_calc_sync_common_timings(gpmc_t, dev_t);

        return 0;
}

/*
 * TODO: remove this function once all peripherals are confirmed to
 * work with generic timing. Simultaneously gpmc_cs_set_timings()
 * has to be modified to handle timings in ps instead of ns
 */
static void gpmc_convert_ps_to_ns(struct gpmc_timings *t)
{
        t->cs_on /= 1000;
        t->cs_rd_off /= 1000;
        t->cs_wr_off /= 1000;
        t->adv_on /= 1000;
        t->adv_rd_off /= 1000;
        t->adv_wr_off /= 1000;
        t->we_on /= 1000;
        t->we_off /= 1000;
        t->oe_on /= 1000;
        t->oe_off /= 1000;
        t->page_burst_access /= 1000;
        t->access /= 1000;
        t->rd_cycle /= 1000;
        t->wr_cycle /= 1000;
        t->bus_turnaround /= 1000;
        t->cycle2cycle_delay /= 1000;
        t->wait_monitoring /= 1000;
        t->clk_activation /= 1000;
        t->wr_access /= 1000;
        t->wr_data_mux_bus /= 1000;
}

int gpmc_calc_timings(struct gpmc_timings *gpmc_t,
                      struct gpmc_settings *gpmc_s,
                      struct gpmc_device_timings *dev_t)
{
        bool mux = false, sync = false;

        if (gpmc_s) {
                mux = gpmc_s->mux_add_data ? true : false;
                sync = (gpmc_s->sync_read || gpmc_s->sync_write);
        }

        memset(gpmc_t, 0, sizeof(*gpmc_t));

        gpmc_calc_common_timings(gpmc_t, dev_t, sync);

        if (gpmc_s && gpmc_s->sync_read)
                gpmc_calc_sync_read_timings(gpmc_t, dev_t, mux);
        else
                gpmc_calc_async_read_timings(gpmc_t, dev_t, mux);

        if (gpmc_s && gpmc_s->sync_write)
                gpmc_calc_sync_write_timings(gpmc_t, dev_t, mux);
        else
                gpmc_calc_async_write_timings(gpmc_t, dev_t, mux);

        /* TODO: remove, see function definition */
        gpmc_convert_ps_to_ns(gpmc_t);

        return 0;
}

/**
 * gpmc_cs_program_settings - programs non-timing related settings
 * @cs:         GPMC chip-select to program
 * @p:          pointer to GPMC settings structure
 *
 * Programs non-timing related settings for a GPMC chip-select, such as
 * bus-width, burst configuration, etc. Function should be called once
 * for each chip-select that is being used and must be called before
 * calling gpmc_cs_set_timings() as timing parameters in the CONFIG1
 * register will be initialised to zero by this function. Returns 0 on
 * success and appropriate negative error code on failure.
 */
int gpmc_cs_program_settings(int cs, struct gpmc_settings *p)
{
        u32 config1;

        if ((!p->device_width) || (p->device_width > GPMC_DEVWIDTH_16BIT)) {
                pr_err("%s: invalid width %d!", __func__, p->device_width);
                return -EINVAL;
        }

        /* Address-data multiplexing not supported for NAND devices */
        if (p->device_nand && p->mux_add_data) {
                pr_err("%s: invalid configuration!\n", __func__);
                return -EINVAL;
        }

        if ((p->mux_add_data > GPMC_MUX_AD) ||
            ((p->mux_add_data == GPMC_MUX_AAD) &&
             !(gpmc_capability & GPMC_HAS_MUX_AAD))) {
                pr_err("%s: invalid multiplex configuration!\n", __func__);
                return -EINVAL;
        }

        /* Page/burst mode supports lengths of 4, 8 and 16 bytes */
        if (p->burst_read || p->burst_write) {
                switch (p->burst_len) {
                case GPMC_BURST_4:
                case GPMC_BURST_8:
                case GPMC_BURST_16:
                        break;
                default:
                        pr_err("%s: invalid page/burst-length (%d)\n",
                               __func__, p->burst_len);
                        return -EINVAL;
                }
        }

        if (p->wait_pin != GPMC_WAITPIN_INVALID &&
            p->wait_pin > gpmc_nr_waitpins) {
                pr_err("%s: invalid wait-pin (%d)\n", __func__, p->wait_pin);
                return -EINVAL;
        }

        config1 = GPMC_CONFIG1_DEVICESIZE((p->device_width - 1));

        if (p->sync_read)
                config1 |= GPMC_CONFIG1_READTYPE_SYNC;
        if (p->sync_write)
                config1 |= GPMC_CONFIG1_WRITETYPE_SYNC;
        if (p->wait_on_read)
                config1 |= GPMC_CONFIG1_WAIT_READ_MON;
        if (p->wait_on_write)
                config1 |= GPMC_CONFIG1_WAIT_WRITE_MON;
        if (p->wait_on_read || p->wait_on_write)
                config1 |= GPMC_CONFIG1_WAIT_PIN_SEL(p->wait_pin);
        if (p->device_nand)
                config1 |= GPMC_CONFIG1_DEVICETYPE(GPMC_DEVICETYPE_NAND);
        if (p->mux_add_data)
                config1 |= GPMC_CONFIG1_MUXTYPE(p->mux_add_data);
        if (p->burst_read)
                config1 |= GPMC_CONFIG1_READMULTIPLE_SUPP;
        if (p->burst_write)
                config1 |= GPMC_CONFIG1_WRITEMULTIPLE_SUPP;
        if (p->burst_read || p->burst_write) {
                config1 |= GPMC_CONFIG1_PAGE_LEN(p->burst_len >> 3);
                config1 |= p->burst_wrap ? GPMC_CONFIG1_WRAPBURST_SUPP : 0;
        }

        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, config1);

        if (p->wait_pin_polarity != GPMC_WAITPINPOLARITY_INVALID) {
                config1 = gpmc_read_reg(GPMC_CONFIG);

                if (p->wait_pin_polarity == GPMC_WAITPINPOLARITY_ACTIVE_LOW)
                        config1 &= ~GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);
                else if (p->wait_pin_polarity == GPMC_WAITPINPOLARITY_ACTIVE_HIGH)
                        config1 |= GPMC_CONFIG_WAITPINPOLARITY(p->wait_pin);

                gpmc_write_reg(GPMC_CONFIG, config1);
        }

        return 0;
}

#ifdef CONFIG_OF
static void gpmc_cs_set_name(int cs, const char *name)
{
        struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

        gpmc->name = name;
}

static const char *gpmc_cs_get_name(int cs)
{
        struct gpmc_cs_data *gpmc = &gpmc_cs[cs];

        return gpmc->name;
}

/**
 * gpmc_cs_remap - remaps a chip-select physical base address
 * @cs:         chip-select to remap
 * @base:       physical base address to re-map chip-select to
 *
 * Re-maps a chip-select to a new physical base address specified by
 * "base". Returns 0 on success and appropriate negative error code
 * on failure.
 */
static int gpmc_cs_remap(int cs, u32 base)
{
        int ret;
        u32 old_base, size;

        if (cs >= gpmc_cs_num) {
                pr_err("%s: requested chip-select is disabled\n", __func__);
                return -ENODEV;
        }

        /*
         * Make sure we ignore any device offsets from the GPMC partition
         * allocated for the chip select and that the new base confirms
         * to the GPMC 16MB minimum granularity.
         */
        base &= ~(SZ_16M - 1);

        gpmc_cs_get_memconf(cs, &old_base, &size);
        if (base == old_base)
                return 0;

        ret = gpmc_cs_delete_mem(cs);
        if (ret < 0)
                return ret;

        ret = gpmc_cs_insert_mem(cs, base, size);
        if (ret < 0)
                return ret;

        ret = gpmc_cs_set_memconf(cs, base, size);

        return ret;
}

/**
 * gpmc_read_settings_dt - read gpmc settings from device-tree
 * @np:         pointer to device-tree node for a gpmc child device
 * @p:          pointer to gpmc settings structure
 *
 * Reads the GPMC settings for a GPMC child device from device-tree and
 * stores them in the GPMC settings structure passed. The GPMC settings
 * structure is initialised to zero by this function and so any
 * previously stored settings will be cleared.
 */
void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
{
        memset(p, 0, sizeof(struct gpmc_settings));

        p->sync_read = of_property_read_bool(np, "gpmc,sync-read");
        p->sync_write = of_property_read_bool(np, "gpmc,sync-write");
        of_property_read_u32(np, "gpmc,device-width", &p->device_width);
        of_property_read_u32(np, "gpmc,mux-add-data", &p->mux_add_data);

        if (!of_property_read_u32(np, "gpmc,burst-length", &p->burst_len)) {
                p->burst_wrap = of_property_read_bool(np, "gpmc,burst-wrap");
                p->burst_read = of_property_read_bool(np, "gpmc,burst-read");
                p->burst_write = of_property_read_bool(np, "gpmc,burst-write");
                if (!p->burst_read && !p->burst_write)
                        pr_warn("%s: page/burst-length set but not used!\n",
                                __func__);
        }

        p->wait_pin = GPMC_WAITPIN_INVALID;
        p->wait_pin_polarity = GPMC_WAITPINPOLARITY_INVALID;

        if (!of_property_read_u32(np, "gpmc,wait-pin", &p->wait_pin)) {
                if (!gpmc_is_valid_waitpin(p->wait_pin)) {
                        pr_err("%s: Invalid wait-pin (%d)\n", __func__, p->wait_pin);
                        p->wait_pin = GPMC_WAITPIN_INVALID;
                }

                if (!of_property_read_u32(np, "ti,wait-pin-polarity",
                                          &p->wait_pin_polarity)) {
                        if (p->wait_pin_polarity != GPMC_WAITPINPOLARITY_ACTIVE_HIGH &&
                            p->wait_pin_polarity != GPMC_WAITPINPOLARITY_ACTIVE_LOW) {
                                pr_err("%s: Invalid wait-pin-polarity (%d)\n",
                                       __func__, p->wait_pin_polarity);
                                p->wait_pin_polarity = GPMC_WAITPINPOLARITY_INVALID;
                                }
                }

                p->wait_on_read = of_property_read_bool(np,
                                                        "gpmc,wait-on-read");
                p->wait_on_write = of_property_read_bool(np,
                                                         "gpmc,wait-on-write");
                if (!p->wait_on_read && !p->wait_on_write)
                        pr_debug("%s: rd/wr wait monitoring not enabled!\n",
                                 __func__);
        }
}

static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
                                                struct gpmc_timings *gpmc_t)
{
        struct gpmc_bool_timings *p;

        if (!np || !gpmc_t)
                return;

        memset(gpmc_t, 0, sizeof(*gpmc_t));

        /* minimum clock period for syncronous mode */
        of_property_read_u32(np, "gpmc,sync-clk-ps", &gpmc_t->sync_clk);

        /* chip select timtings */
        of_property_read_u32(np, "gpmc,cs-on-ns", &gpmc_t->cs_on);
        of_property_read_u32(np, "gpmc,cs-rd-off-ns", &gpmc_t->cs_rd_off);
        of_property_read_u32(np, "gpmc,cs-wr-off-ns", &gpmc_t->cs_wr_off);

        /* ADV signal timings */
        of_property_read_u32(np, "gpmc,adv-on-ns", &gpmc_t->adv_on);
        of_property_read_u32(np, "gpmc,adv-rd-off-ns", &gpmc_t->adv_rd_off);
        of_property_read_u32(np, "gpmc,adv-wr-off-ns", &gpmc_t->adv_wr_off);
        of_property_read_u32(np, "gpmc,adv-aad-mux-on-ns",
                             &gpmc_t->adv_aad_mux_on);
        of_property_read_u32(np, "gpmc,adv-aad-mux-rd-off-ns",
                             &gpmc_t->adv_aad_mux_rd_off);
        of_property_read_u32(np, "gpmc,adv-aad-mux-wr-off-ns",
                             &gpmc_t->adv_aad_mux_wr_off);

        /* WE signal timings */
        of_property_read_u32(np, "gpmc,we-on-ns", &gpmc_t->we_on);
        of_property_read_u32(np, "gpmc,we-off-ns", &gpmc_t->we_off);

        /* OE signal timings */
        of_property_read_u32(np, "gpmc,oe-on-ns", &gpmc_t->oe_on);
        of_property_read_u32(np, "gpmc,oe-off-ns", &gpmc_t->oe_off);
        of_property_read_u32(np, "gpmc,oe-aad-mux-on-ns",
                             &gpmc_t->oe_aad_mux_on);
        of_property_read_u32(np, "gpmc,oe-aad-mux-off-ns",
                             &gpmc_t->oe_aad_mux_off);

        /* access and cycle timings */
        of_property_read_u32(np, "gpmc,page-burst-access-ns",
                             &gpmc_t->page_burst_access);
        of_property_read_u32(np, "gpmc,access-ns", &gpmc_t->access);
        of_property_read_u32(np, "gpmc,rd-cycle-ns", &gpmc_t->rd_cycle);
        of_property_read_u32(np, "gpmc,wr-cycle-ns", &gpmc_t->wr_cycle);
        of_property_read_u32(np, "gpmc,bus-turnaround-ns",
                             &gpmc_t->bus_turnaround);
        of_property_read_u32(np, "gpmc,cycle2cycle-delay-ns",
                             &gpmc_t->cycle2cycle_delay);
        of_property_read_u32(np, "gpmc,wait-monitoring-ns",
                             &gpmc_t->wait_monitoring);
        of_property_read_u32(np, "gpmc,clk-activation-ns",
                             &gpmc_t->clk_activation);

        /* only applicable to OMAP3+ */
        of_property_read_u32(np, "gpmc,wr-access-ns", &gpmc_t->wr_access);
        of_property_read_u32(np, "gpmc,wr-data-mux-bus-ns",
                             &gpmc_t->wr_data_mux_bus);

        /* bool timing parameters */
        p = &gpmc_t->bool_timings;

        p->cycle2cyclediffcsen =
                of_property_read_bool(np, "gpmc,cycle2cycle-diffcsen");
        p->cycle2cyclesamecsen =
                of_property_read_bool(np, "gpmc,cycle2cycle-samecsen");
        p->we_extra_delay = of_property_read_bool(np, "gpmc,we-extra-delay");
        p->oe_extra_delay = of_property_read_bool(np, "gpmc,oe-extra-delay");
        p->adv_extra_delay = of_property_read_bool(np, "gpmc,adv-extra-delay");
        p->cs_extra_delay = of_property_read_bool(np, "gpmc,cs-extra-delay");
        p->time_para_granularity =
                of_property_read_bool(np, "gpmc,time-para-granularity");
}

/**
 * gpmc_probe_generic_child - configures the gpmc for a child device
 * @pdev:       pointer to gpmc platform device
 * @child:      pointer to device-tree node for child device
 *
 * Allocates and configures a GPMC chip-select for a child device.
 * Returns 0 on success and appropriate negative error code on failure.
 */
static int gpmc_probe_generic_child(struct platform_device *pdev,
                                struct device_node *child)
{
        struct gpmc_settings gpmc_s;
        struct gpmc_timings gpmc_t;
        struct resource res;
        unsigned long base;
        const char *name;
        int ret, cs;
        u32 val;
        struct gpmc_device *gpmc = platform_get_drvdata(pdev);

        if (of_property_read_u32(child, "reg", &cs) < 0) {
                dev_err(&pdev->dev, "%pOF has no 'reg' property\n",
                        child);
                return -ENODEV;
        }

        if (of_address_to_resource(child, 0, &res) < 0) {
                dev_err(&pdev->dev, "%pOF has malformed 'reg' property\n",
                        child);
                return -ENODEV;
        }

        /*
         * Check if we have multiple instances of the same device
         * on a single chip select. If so, use the already initialized
         * timings.
         */
        name = gpmc_cs_get_name(cs);
        if (name && of_node_name_eq(child, name))
                goto no_timings;

        ret = gpmc_cs_request(cs, resource_size(&res), &base);
        if (ret < 0) {
                dev_err(&pdev->dev, "cannot request GPMC CS %d\n", cs);
                return ret;
        }
        gpmc_cs_set_name(cs, child->full_name);

        gpmc_read_settings_dt(child, &gpmc_s);
        gpmc_read_timings_dt(child, &gpmc_t);

        /*
         * For some GPMC devices we still need to rely on the bootloader
         * timings because the devices can be connected via FPGA.
         * REVISIT: Add timing support from slls644g.pdf.
         */
        if (!gpmc_t.cs_rd_off) {
                WARN(1, "enable GPMC debug to configure .dts timings for CS%i\n",
                        cs);
                gpmc_cs_show_timings(cs,
                                     "please add GPMC bootloader timings to .dts");
                goto no_timings;
        }

        /* CS must be disabled while making changes to gpmc configuration */
        gpmc_cs_disable_mem(cs);

        /*
         * FIXME: gpmc_cs_request() will map the CS to an arbitrary
         * location in the gpmc address space. When booting with
         * device-tree we want the NOR flash to be mapped to the
         * location specified in the device-tree blob. So remap the
         * CS to this location. Once DT migration is complete should
         * just make gpmc_cs_request() map a specific address.
         */
        ret = gpmc_cs_remap(cs, res.start);
        if (ret < 0) {
                dev_err(&pdev->dev, "cannot remap GPMC CS %d to %pa\n",
                        cs, &res.start);
                if (res.start < GPMC_MEM_START) {
                        dev_info(&pdev->dev,
                                 "GPMC CS %d start cannot be lesser than 0x%x\n",
                                 cs, GPMC_MEM_START);
                } else if (res.end > GPMC_MEM_END) {
                        dev_info(&pdev->dev,
                                 "GPMC CS %d end cannot be greater than 0x%x\n",
                                 cs, GPMC_MEM_END);
                }
                goto err;
        }

        if (of_match_node(omap_nand_ids, child)) {
                /* NAND specific setup */
                val = 8;
                of_property_read_u32(child, "nand-bus-width", &val);
                switch (val) {
                case 8:
                        gpmc_s.device_width = GPMC_DEVWIDTH_8BIT;
                        break;
                case 16:
                        gpmc_s.device_width = GPMC_DEVWIDTH_16BIT;
                        break;
                default:
                        dev_err(&pdev->dev, "%pOFn: invalid 'nand-bus-width'\n",
                                child);
                        ret = -EINVAL;
                        goto err;
                }

                /* disable write protect */
                gpmc_configure(GPMC_CONFIG_WP, 0);
                gpmc_s.device_nand = true;
        } else {
                ret = of_property_read_u32(child, "bank-width",
                                           &gpmc_s.device_width);
                if (ret < 0 && !gpmc_s.device_width) {
                        dev_err(&pdev->dev,
                                "%pOF has no 'gpmc,device-width' property\n",
                                child);
                        goto err;
                }
        }

        /* Reserve wait pin if it is required and valid */
        if (gpmc_s.wait_on_read || gpmc_s.wait_on_write) {
                ret = gpmc_alloc_waitpin(gpmc, &gpmc_s);
                if (ret < 0)
                        goto err;
        }

        gpmc_cs_show_timings(cs, "before gpmc_cs_program_settings");

        ret = gpmc_cs_program_settings(cs, &gpmc_s);
        if (ret < 0)
                goto err_cs;

        ret = gpmc_cs_set_timings(cs, &gpmc_t, &gpmc_s);
        if (ret) {
                dev_err(&pdev->dev, "failed to set gpmc timings for: %pOFn\n",
                        child);
                goto err_cs;
        }

        /* Clear limited address i.e. enable A26-A11 */
        val = gpmc_read_reg(GPMC_CONFIG);
        val &= ~GPMC_CONFIG_LIMITEDADDRESS;
        gpmc_write_reg(GPMC_CONFIG, val);

        /* Enable CS region */
        gpmc_cs_enable_mem(cs);

no_timings:

        /* create platform device, NULL on error or when disabled */
        if (!of_platform_device_create(child, NULL, &pdev->dev))
                goto err_child_fail;

        /* create children and other common bus children */
        if (of_platform_default_populate(child, NULL, &pdev->dev))
                goto err_child_fail;

        return 0;

err_child_fail:

        dev_err(&pdev->dev, "failed to create gpmc child %pOFn\n", child);
        ret = -ENODEV;

err_cs:
        gpmc_free_waitpin(gpmc, gpmc_s.wait_pin);
err:
        gpmc_cs_free(cs);

        return ret;
}

static const struct of_device_id gpmc_dt_ids[];

static int gpmc_probe_dt(struct platform_device *pdev)
{
        int ret;
        const struct of_device_id *of_id =
                of_match_device(gpmc_dt_ids, &pdev->dev);

        if (!of_id)
                return 0;

        ret = of_property_read_u32(pdev->dev.of_node, "gpmc,num-cs",
                                   &gpmc_cs_num);
        if (ret < 0) {
                pr_err("%s: number of chip-selects not defined\n", __func__);
                return ret;
        } else if (gpmc_cs_num < 1) {
                pr_err("%s: all chip-selects are disabled\n", __func__);
                return -EINVAL;
        } else if (gpmc_cs_num > GPMC_CS_NUM) {
                pr_err("%s: number of supported chip-selects cannot be > %d\n",
                                         __func__, GPMC_CS_NUM);
                return -EINVAL;
        }

        ret = of_property_read_u32(pdev->dev.of_node, "gpmc,num-waitpins",
                                   &gpmc_nr_waitpins);
        if (ret < 0) {
                pr_err("%s: number of wait pins not found!\n", __func__);
                return ret;
        }

        return 0;
}

static void gpmc_probe_dt_children(struct platform_device *pdev)
{
        int ret;
        struct device_node *child;

        for_each_available_child_of_node(pdev->dev.of_node, child) {
                ret = gpmc_probe_generic_child(pdev, child);
                if (ret) {
                        dev_err(&pdev->dev, "failed to probe DT child '%pOFn': %d\n",
                                child, ret);
                }
        }
}
#else
void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
{
        memset(p, 0, sizeof(*p));
}
static int gpmc_probe_dt(struct platform_device *pdev)
{
        return 0;
}

static void gpmc_probe_dt_children(struct platform_device *pdev)
{
}
#endif /* CONFIG_OF */

static int gpmc_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
        return GPIO_LINE_DIRECTION_IN; /* we're input only */
}

static int gpmc_gpio_direction_input(struct gpio_chip *chip,
                                     unsigned int offset)
{
        return 0;       /* we're input only */
}

static int gpmc_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
        u32 reg;

        offset += 8;

        reg = gpmc_read_reg(GPMC_STATUS) & BIT(offset);

        return !!reg;
}

static int gpmc_gpio_init(struct gpmc_device *gpmc)
{
        int ret;

        gpmc->gpio_chip.parent = gpmc->dev;
        gpmc->gpio_chip.owner = THIS_MODULE;
        gpmc->gpio_chip.label = DEVICE_NAME;
        gpmc->gpio_chip.ngpio = gpmc_nr_waitpins;
        gpmc->gpio_chip.get_direction = gpmc_gpio_get_direction;
        gpmc->gpio_chip.direction_input = gpmc_gpio_direction_input;
        gpmc->gpio_chip.get = gpmc_gpio_get;
        gpmc->gpio_chip.base = -1;

        ret = devm_gpiochip_add_data(gpmc->dev, &gpmc->gpio_chip, NULL);
        if (ret < 0) {
                dev_err(gpmc->dev, "could not register gpio chip: %d\n", ret);
                return ret;
        }

        return 0;
}

static void omap3_gpmc_save_context(struct gpmc_device *gpmc)
{
        struct omap3_gpmc_regs *gpmc_context;
        int i;

        if (!gpmc || !gpmc_base)
                return;

        gpmc_context = &gpmc->context;

        gpmc_context->sysconfig = gpmc_read_reg(GPMC_SYSCONFIG);
        gpmc_context->irqenable = gpmc_read_reg(GPMC_IRQENABLE);
        gpmc_context->timeout_ctrl = gpmc_read_reg(GPMC_TIMEOUT_CONTROL);
        gpmc_context->config = gpmc_read_reg(GPMC_CONFIG);
        gpmc_context->prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1);
        gpmc_context->prefetch_config2 = gpmc_read_reg(GPMC_PREFETCH_CONFIG2);
        gpmc_context->prefetch_control = gpmc_read_reg(GPMC_PREFETCH_CONTROL);
        for (i = 0; i < gpmc_cs_num; i++) {
                gpmc_context->cs_context[i].is_valid = gpmc_cs_mem_enabled(i);
                if (gpmc_context->cs_context[i].is_valid) {
                        gpmc_context->cs_context[i].config1 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG1);
                        gpmc_context->cs_context[i].config2 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG2);
                        gpmc_context->cs_context[i].config3 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG3);
                        gpmc_context->cs_context[i].config4 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG4);
                        gpmc_context->cs_context[i].config5 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG5);
                        gpmc_context->cs_context[i].config6 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG6);
                        gpmc_context->cs_context[i].config7 =
                                gpmc_cs_read_reg(i, GPMC_CS_CONFIG7);
                }
        }
}

static void omap3_gpmc_restore_context(struct gpmc_device *gpmc)
{
        struct omap3_gpmc_regs *gpmc_context;
        int i;

        if (!gpmc || !gpmc_base)
                return;

        gpmc_context = &gpmc->context;

        gpmc_write_reg(GPMC_SYSCONFIG, gpmc_context->sysconfig);
        gpmc_write_reg(GPMC_IRQENABLE, gpmc_context->irqenable);
        gpmc_write_reg(GPMC_TIMEOUT_CONTROL, gpmc_context->timeout_ctrl);
        gpmc_write_reg(GPMC_CONFIG, gpmc_context->config);
        gpmc_write_reg(GPMC_PREFETCH_CONFIG1, gpmc_context->prefetch_config1);
        gpmc_write_reg(GPMC_PREFETCH_CONFIG2, gpmc_context->prefetch_config2);
        gpmc_write_reg(GPMC_PREFETCH_CONTROL, gpmc_context->prefetch_control);
        for (i = 0; i < gpmc_cs_num; i++) {
                if (gpmc_context->cs_context[i].is_valid) {
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG1,
                                          gpmc_context->cs_context[i].config1);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG2,
                                          gpmc_context->cs_context[i].config2);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG3,
                                          gpmc_context->cs_context[i].config3);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG4,
                                          gpmc_context->cs_context[i].config4);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG5,
                                          gpmc_context->cs_context[i].config5);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG6,
                                          gpmc_context->cs_context[i].config6);
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG7,
                                          gpmc_context->cs_context[i].config7);
                } else {
                        gpmc_cs_write_reg(i, GPMC_CS_CONFIG7, 0);
                }
        }
}

static int omap_gpmc_context_notifier(struct notifier_block *nb,
                                      unsigned long cmd, void *v)
{
        struct gpmc_device *gpmc;

        gpmc = container_of(nb, struct gpmc_device, nb);
        if (gpmc->is_suspended || pm_runtime_suspended(gpmc->dev))
                return NOTIFY_OK;

        switch (cmd) {
        case CPU_CLUSTER_PM_ENTER:
                omap3_gpmc_save_context(gpmc);
                break;
        case CPU_CLUSTER_PM_ENTER_FAILED:       /* No need to restore context */
                break;
        case CPU_CLUSTER_PM_EXIT:
                omap3_gpmc_restore_context(gpmc);
                break;
        }

        return NOTIFY_OK;
}

static int gpmc_probe(struct platform_device *pdev)
{
        int rc, i;
        u32 l;
        struct resource *res;
        struct gpmc_device *gpmc;

        gpmc = devm_kzalloc(&pdev->dev, sizeof(*gpmc), GFP_KERNEL);
        if (!gpmc)
                return -ENOMEM;

        gpmc->dev = &pdev->dev;
        platform_set_drvdata(pdev, gpmc);

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
        if (!res) {
                /* legacy DT */
                gpmc_base = devm_platform_ioremap_resource(pdev, 0);
                if (IS_ERR(gpmc_base))
                        return PTR_ERR(gpmc_base);
        } else {
                gpmc_base = devm_ioremap_resource(&pdev->dev, res);
                if (IS_ERR(gpmc_base))
                        return PTR_ERR(gpmc_base);

                res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "data");
                if (!res) {
                        dev_err(&pdev->dev, "couldn't get data reg resource\n");
                        return -ENOENT;
                }

                gpmc->data = res;
        }

        gpmc->irq = platform_get_irq(pdev, 0);
        if (gpmc->irq < 0)
                return gpmc->irq;

        gpmc_l3_clk = devm_clk_get(&pdev->dev, "fck");
        if (IS_ERR(gpmc_l3_clk)) {
                dev_err(&pdev->dev, "Failed to get GPMC fck\n");
                return PTR_ERR(gpmc_l3_clk);
        }

        if (!clk_get_rate(gpmc_l3_clk)) {
                dev_err(&pdev->dev, "Invalid GPMC fck clock rate\n");
                return -EINVAL;
        }

        if (pdev->dev.of_node) {
                rc = gpmc_probe_dt(pdev);
                if (rc)
                        return rc;
        } else {
                gpmc_cs_num = GPMC_CS_NUM;
                gpmc_nr_waitpins = GPMC_NR_WAITPINS;
        }

        gpmc->waitpins = devm_kzalloc(&pdev->dev,
                                      gpmc_nr_waitpins * sizeof(struct gpmc_waitpin),
                                      GFP_KERNEL);
        if (!gpmc->waitpins)
                return -ENOMEM;

        for (i = 0; i < gpmc_nr_waitpins; i++)
                gpmc->waitpins[i].pin = GPMC_WAITPIN_INVALID;

        pm_runtime_enable(&pdev->dev);
        pm_runtime_get_sync(&pdev->dev);

        l = gpmc_read_reg(GPMC_REVISION);

        /*
         * FIXME: Once device-tree migration is complete the below flags
         * should be populated based upon the device-tree compatible
         * string. For now just use the IP revision. OMAP3+ devices have
         * the wr_access and wr_data_mux_bus register fields. OMAP4+
         * devices support the addr-addr-data multiplex protocol.
         *
         * GPMC IP revisions:
         * - OMAP24xx                   = 2.0
         * - OMAP3xxx                   = 5.0
         * - OMAP44xx/54xx/AM335x       = 6.0
         */
        if (GPMC_REVISION_MAJOR(l) > 0x4)
                gpmc_capability = GPMC_HAS_WR_ACCESS | GPMC_HAS_WR_DATA_MUX_BUS;
        if (GPMC_REVISION_MAJOR(l) > 0x5)
                gpmc_capability |= GPMC_HAS_MUX_AAD;
        dev_info(gpmc->dev, "GPMC revision %d.%d\n", GPMC_REVISION_MAJOR(l),
                 GPMC_REVISION_MINOR(l));

        gpmc_mem_init(gpmc);
        rc = gpmc_gpio_init(gpmc);
        if (rc)
                goto gpio_init_failed;

        gpmc->nirqs = GPMC_NR_NAND_IRQS + gpmc_nr_waitpins;
        rc = gpmc_setup_irq(gpmc);
        if (rc) {
                dev_err(gpmc->dev, "gpmc_setup_irq failed\n");
                goto gpio_init_failed;
        }

        gpmc_probe_dt_children(pdev);

        gpmc->nb.notifier_call = omap_gpmc_context_notifier;
        cpu_pm_register_notifier(&gpmc->nb);

        return 0;

gpio_init_failed:
        gpmc_mem_exit();
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);

        return rc;
}

static void gpmc_remove(struct platform_device *pdev)
{
        int i;
        struct gpmc_device *gpmc = platform_get_drvdata(pdev);

        cpu_pm_unregister_notifier(&gpmc->nb);
        for (i = 0; i < gpmc_nr_waitpins; i++)
                gpmc_free_waitpin(gpmc, i);
        gpmc_free_irq(gpmc);
        gpmc_mem_exit();
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
}

#ifdef CONFIG_PM_SLEEP
static int gpmc_suspend(struct device *dev)
{
        struct gpmc_device *gpmc = dev_get_drvdata(dev);

        omap3_gpmc_save_context(gpmc);
        pm_runtime_put_sync(dev);
        gpmc->is_suspended = 1;

        return 0;
}

static int gpmc_resume(struct device *dev)
{
        struct gpmc_device *gpmc = dev_get_drvdata(dev);

        pm_runtime_get_sync(dev);
        omap3_gpmc_restore_context(gpmc);
        gpmc->is_suspended = 0;

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(gpmc_pm_ops, gpmc_suspend, gpmc_resume);

#ifdef CONFIG_OF
static const struct of_device_id gpmc_dt_ids[] = {
        { .compatible = "ti,omap2420-gpmc" },
        { .compatible = "ti,omap2430-gpmc" },
        { .compatible = "ti,omap3430-gpmc" },   /* omap3430 & omap3630 */
        { .compatible = "ti,omap4430-gpmc" },   /* omap4430 & omap4460 & omap543x */
        { .compatible = "ti,am3352-gpmc" },     /* am335x devices */
        { .compatible = "ti,am64-gpmc" },
        { }
};
MODULE_DEVICE_TABLE(of, gpmc_dt_ids);
#endif

static struct platform_driver gpmc_driver = {
        .probe          = gpmc_probe,
        .remove         = gpmc_remove,
        .driver         = {
                .name   = DEVICE_NAME,
                .of_match_table = of_match_ptr(gpmc_dt_ids),
                .pm     = &gpmc_pm_ops,
        },
};

module_platform_driver(gpmc_driver);

MODULE_DESCRIPTION("Texas Instruments GPMC driver");
MODULE_LICENSE("GPL");