// SPDX-License-Identifier: GPL-2.0-only
/* linux/drivers/mfd/sm501.c
 *
 * Copyright (C) 2006 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *      Vincent Sanders <vince@simtec.co.uk>
 *
 * SM501 MFD driver
*/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <linux/platform_data/i2c-gpio.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/slab.h>

#include <linux/sm501.h>
#include <linux/sm501-regs.h>
#include <linux/serial_8250.h>

#include <linux/io.h>

struct sm501_device {
        struct list_head                list;
        struct platform_device          pdev;
};

struct sm501_gpio;

#ifdef CONFIG_MFD_SM501_GPIO
#include <linux/gpio.h>

struct sm501_gpio_chip {
        struct gpio_chip        gpio;
        struct sm501_gpio       *ourgpio;       /* to get back to parent. */
        void __iomem            *regbase;
        void __iomem            *control;       /* address of control reg. */
};

struct sm501_gpio {
        struct sm501_gpio_chip  low;
        struct sm501_gpio_chip  high;
        spinlock_t              lock;

        unsigned int             registered : 1;
        void __iomem            *regs;
        struct resource         *regs_res;
};
#else
struct sm501_gpio {
        /* no gpio support, empty definition for sm501_devdata. */
};
#endif

struct sm501_devdata {
        spinlock_t                       reg_lock;
        struct mutex                     clock_lock;
        struct list_head                 devices;
        struct sm501_gpio                gpio;

        struct device                   *dev;
        struct resource                 *io_res;
        struct resource                 *mem_res;
        struct resource                 *regs_claim;
        struct sm501_platdata           *platdata;


        unsigned int                     in_suspend;
        unsigned long                    pm_misc;

        int                              unit_power[20];
        unsigned int                     pdev_id;
        unsigned int                     irq;
        void __iomem                    *regs;
        unsigned int                     rev;
};


#define MHZ (1000 * 1000)

#ifdef DEBUG
static const unsigned int div_tab[] = {
        [0]             = 1,
        [1]             = 2,
        [2]             = 4,
        [3]             = 8,
        [4]             = 16,
        [5]             = 32,
        [6]             = 64,
        [7]             = 128,
        [8]             = 3,
        [9]             = 6,
        [10]            = 12,
        [11]            = 24,
        [12]            = 48,
        [13]            = 96,
        [14]            = 192,
        [15]            = 384,
        [16]            = 5,
        [17]            = 10,
        [18]            = 20,
        [19]            = 40,
        [20]            = 80,
        [21]            = 160,
        [22]            = 320,
        [23]            = 604,
};

static unsigned long decode_div(unsigned long pll2, unsigned long val,
                                unsigned int lshft, unsigned int selbit,
                                unsigned long mask)
{
        if (val & selbit)
                pll2 = 288 * MHZ;

        return pll2 / div_tab[(val >> lshft) & mask];
}

#define fmt_freq(x) ((x) / MHZ), ((x) % MHZ), (x)

/* sm501_dump_clk
 *
 * Print out the current clock configuration for the device
*/

static void sm501_dump_clk(struct sm501_devdata *sm)
{
        unsigned long misct = smc501_readl(sm->regs + SM501_MISC_TIMING);
        unsigned long pm0 = smc501_readl(sm->regs + SM501_POWER_MODE_0_CLOCK);
        unsigned long pm1 = smc501_readl(sm->regs + SM501_POWER_MODE_1_CLOCK);
        unsigned long pmc = smc501_readl(sm->regs + SM501_POWER_MODE_CONTROL);
        unsigned long sdclk0, sdclk1;
        unsigned long pll2 = 0;

        switch (misct & 0x30) {
        case 0x00:
                pll2 = 336 * MHZ;
                break;
        case 0x10:
                pll2 = 288 * MHZ;
                break;
        case 0x20:
                pll2 = 240 * MHZ;
                break;
        case 0x30:
                pll2 = 192 * MHZ;
                break;
        }

        sdclk0 = (misct & (1<<12)) ? pll2 : 288 * MHZ;
        sdclk0 /= div_tab[((misct >> 8) & 0xf)];

        sdclk1 = (misct & (1<<20)) ? pll2 : 288 * MHZ;
        sdclk1 /= div_tab[((misct >> 16) & 0xf)];

        dev_dbg(sm->dev, "MISCT=%08lx, PM0=%08lx, PM1=%08lx\n",
                misct, pm0, pm1);

        dev_dbg(sm->dev, "PLL2 = %ld.%ld MHz (%ld), SDCLK0=%08lx, SDCLK1=%08lx\n",
                fmt_freq(pll2), sdclk0, sdclk1);

        dev_dbg(sm->dev, "SDRAM: PM0=%ld, PM1=%ld\n", sdclk0, sdclk1);

        dev_dbg(sm->dev, "PM0[%c]: "
                 "P2 %ld.%ld MHz (%ld), V2 %ld.%ld (%ld), "
                 "M %ld.%ld (%ld), MX1 %ld.%ld (%ld)\n",
                 (pmc & 3 ) == 0 ? '*' : '-',
                 fmt_freq(decode_div(pll2, pm0, 24, 1<<29, 31)),
                 fmt_freq(decode_div(pll2, pm0, 16, 1<<20, 15)),
                 fmt_freq(decode_div(pll2, pm0, 8,  1<<12, 15)),
                 fmt_freq(decode_div(pll2, pm0, 0,  1<<4,  15)));

        dev_dbg(sm->dev, "PM1[%c]: "
                "P2 %ld.%ld MHz (%ld), V2 %ld.%ld (%ld), "
                "M %ld.%ld (%ld), MX1 %ld.%ld (%ld)\n",
                (pmc & 3 ) == 1 ? '*' : '-',
                fmt_freq(decode_div(pll2, pm1, 24, 1<<29, 31)),
                fmt_freq(decode_div(pll2, pm1, 16, 1<<20, 15)),
                fmt_freq(decode_div(pll2, pm1, 8,  1<<12, 15)),
                fmt_freq(decode_div(pll2, pm1, 0,  1<<4,  15)));
}

static void sm501_dump_regs(struct sm501_devdata *sm)
{
        void __iomem *regs = sm->regs;

        dev_info(sm->dev, "System Control   %08x\n",
                        smc501_readl(regs + SM501_SYSTEM_CONTROL));
        dev_info(sm->dev, "Misc Control     %08x\n",
                        smc501_readl(regs + SM501_MISC_CONTROL));
        dev_info(sm->dev, "GPIO Control Low %08x\n",
                        smc501_readl(regs + SM501_GPIO31_0_CONTROL));
        dev_info(sm->dev, "GPIO Control Hi  %08x\n",
                        smc501_readl(regs + SM501_GPIO63_32_CONTROL));
        dev_info(sm->dev, "DRAM Control     %08x\n",
                        smc501_readl(regs + SM501_DRAM_CONTROL));
        dev_info(sm->dev, "Arbitration Ctrl %08x\n",
                        smc501_readl(regs + SM501_ARBTRTN_CONTROL));
        dev_info(sm->dev, "Misc Timing      %08x\n",
                        smc501_readl(regs + SM501_MISC_TIMING));
}

static void sm501_dump_gate(struct sm501_devdata *sm)
{
        dev_info(sm->dev, "CurrentGate      %08x\n",
                        smc501_readl(sm->regs + SM501_CURRENT_GATE));
        dev_info(sm->dev, "CurrentClock     %08x\n",
                        smc501_readl(sm->regs + SM501_CURRENT_CLOCK));
        dev_info(sm->dev, "PowerModeControl %08x\n",
                        smc501_readl(sm->regs + SM501_POWER_MODE_CONTROL));
}

#else
static inline void sm501_dump_gate(struct sm501_devdata *sm) { }
static inline void sm501_dump_regs(struct sm501_devdata *sm) { }
static inline void sm501_dump_clk(struct sm501_devdata *sm) { }
#endif

/* sm501_sync_regs
 *
 * ensure the
*/

static void sm501_sync_regs(struct sm501_devdata *sm)
{
        smc501_readl(sm->regs);
}

static inline void sm501_mdelay(struct sm501_devdata *sm, unsigned int delay)
{
        /* during suspend/resume, we are currently not allowed to sleep,
         * so change to using mdelay() instead of msleep() if we
         * are in one of these paths */

        if (sm->in_suspend)
                mdelay(delay);
        else
                msleep(delay);
}

/* sm501_misc_control
 *
 * alters the miscellaneous control parameters
*/

int sm501_misc_control(struct device *dev,
                       unsigned long set, unsigned long clear)
{
        struct sm501_devdata *sm = dev_get_drvdata(dev);
        unsigned long misc;
        unsigned long save;
        unsigned long to;

        spin_lock_irqsave(&sm->reg_lock, save);

        misc = smc501_readl(sm->regs + SM501_MISC_CONTROL);
        to = (misc & ~clear) | set;

        if (to != misc) {
                smc501_writel(to, sm->regs + SM501_MISC_CONTROL);
                sm501_sync_regs(sm);

                dev_dbg(sm->dev, "MISC_CONTROL %08lx\n", misc);
        }

        spin_unlock_irqrestore(&sm->reg_lock, save);
        return to;
}

EXPORT_SYMBOL_GPL(sm501_misc_control);

/* sm501_modify_reg
 *
 * Modify a register in the SM501 which may be shared with other
 * drivers.
*/

unsigned long sm501_modify_reg(struct device *dev,
                               unsigned long reg,
                               unsigned long set,
                               unsigned long clear)
{
        struct sm501_devdata *sm = dev_get_drvdata(dev);
        unsigned long data;
        unsigned long save;

        spin_lock_irqsave(&sm->reg_lock, save);

        data = smc501_readl(sm->regs + reg);
        data |= set;
        data &= ~clear;

        smc501_writel(data, sm->regs + reg);
        sm501_sync_regs(sm);

        spin_unlock_irqrestore(&sm->reg_lock, save);

        return data;
}

EXPORT_SYMBOL_GPL(sm501_modify_reg);

/* sm501_unit_power
 *
 * alters the power active gate to set specific units on or off
 */

int sm501_unit_power(struct device *dev, unsigned int unit, unsigned int to)
{
        struct sm501_devdata *sm = dev_get_drvdata(dev);
        unsigned long mode;
        unsigned long gate;
        unsigned long clock;

        mutex_lock(&sm->clock_lock);

        mode = smc501_readl(sm->regs + SM501_POWER_MODE_CONTROL);
        gate = smc501_readl(sm->regs + SM501_CURRENT_GATE);
        clock = smc501_readl(sm->regs + SM501_CURRENT_CLOCK);

        mode &= 3;              /* get current power mode */

        if (unit >= ARRAY_SIZE(sm->unit_power)) {
                dev_err(dev, "%s: bad unit %d\n", __func__, unit);
                goto already;
        }

        dev_dbg(sm->dev, "%s: unit %d, cur %d, to %d\n", __func__, unit,
                sm->unit_power[unit], to);

        if (to == 0 && sm->unit_power[unit] == 0) {
                dev_err(sm->dev, "unit %d is already shutdown\n", unit);
                goto already;
        }

        sm->unit_power[unit] += to ? 1 : -1;
        to = sm->unit_power[unit] ? 1 : 0;

        if (to) {
                if (gate & (1 << unit))
                        goto already;
                gate |= (1 << unit);
        } else {
                if (!(gate & (1 << unit)))
                        goto already;
                gate &= ~(1 << unit);
        }

        switch (mode) {
        case 1:
                smc501_writel(gate, sm->regs + SM501_POWER_MODE_0_GATE);
                smc501_writel(clock, sm->regs + SM501_POWER_MODE_0_CLOCK);
                mode = 0;
                break;
        case 2:
        case 0:
                smc501_writel(gate, sm->regs + SM501_POWER_MODE_1_GATE);
                smc501_writel(clock, sm->regs + SM501_POWER_MODE_1_CLOCK);
                mode = 1;
                break;

        default:
                gate = -1;
                goto already;
        }

        smc501_writel(mode, sm->regs + SM501_POWER_MODE_CONTROL);
        sm501_sync_regs(sm);

        dev_dbg(sm->dev, "gate %08lx, clock %08lx, mode %08lx\n",
                gate, clock, mode);

        sm501_mdelay(sm, 16);

 already:
        mutex_unlock(&sm->clock_lock);
        return gate;
}

EXPORT_SYMBOL_GPL(sm501_unit_power);

/* clock value structure. */
struct sm501_clock {
        unsigned long mclk;
        int divider;
        int shift;
        unsigned int m, n, k;
};

/* sm501_calc_clock
 *
 * Calculates the nearest discrete clock frequency that
 * can be achieved with the specified input clock.
 *   the maximum divisor is 3 or 5
 */

static int sm501_calc_clock(unsigned long freq,
                            struct sm501_clock *clock,
                            int max_div,
                            unsigned long mclk,
                            long *best_diff)
{
        int ret = 0;
        int divider;
        int shift;
        long diff;

        /* try dividers 1 and 3 for CRT and for panel,
           try divider 5 for panel only.*/

        for (divider = 1; divider <= max_div; divider += 2) {
                /* try all 8 shift values.*/
                for (shift = 0; shift < 8; shift++) {
                        /* Calculate difference to requested clock */
                        diff = DIV_ROUND_CLOSEST(mclk, divider << shift) - freq;
                        if (diff < 0)
                                diff = -diff;

                        /* If it is less than the current, use it */
                        if (diff < *best_diff) {
                                *best_diff = diff;

                                clock->mclk = mclk;
                                clock->divider = divider;
                                clock->shift = shift;
                                ret = 1;
                        }
                }
        }

        return ret;
}

/* sm501_calc_pll
 *
 * Calculates the nearest discrete clock frequency that can be
 * achieved using the programmable PLL.
 *   the maximum divisor is 3 or 5
 */

static unsigned long sm501_calc_pll(unsigned long freq,
                                        struct sm501_clock *clock,
                                        int max_div)
{
        unsigned long mclk;
        unsigned int m, n, k;
        long best_diff = 999999999;

        /*
         * The SM502 datasheet doesn't specify the min/max values for M and N.
         * N = 1 at least doesn't work in practice.
         */
        for (m = 2; m <= 255; m++) {
                for (n = 2; n <= 127; n++) {
                        for (k = 0; k <= 1; k++) {
                                mclk = (24000000UL * m / n) >> k;

                                if (sm501_calc_clock(freq, clock, max_div,
                                                     mclk, &best_diff)) {
                                        clock->m = m;
                                        clock->n = n;
                                        clock->k = k;
                                }
                        }
                }
        }

        /* Return best clock. */
        return clock->mclk / (clock->divider << clock->shift);
}

/* sm501_select_clock
 *
 * Calculates the nearest discrete clock frequency that can be
 * achieved using the 288MHz and 336MHz PLLs.
 *   the maximum divisor is 3 or 5
 */

static unsigned long sm501_select_clock(unsigned long freq,
                                        struct sm501_clock *clock,
                                        int max_div)
{
        unsigned long mclk;
        long best_diff = 999999999;

        /* Try 288MHz and 336MHz clocks. */
        for (mclk = 288000000; mclk <= 336000000; mclk += 48000000) {
                sm501_calc_clock(freq, clock, max_div, mclk, &best_diff);
        }

        /* Return best clock. */
        return clock->mclk / (clock->divider << clock->shift);
}

/* sm501_set_clock
 *
 * set one of the four clock sources to the closest available frequency to
 *  the one specified
*/

unsigned long sm501_set_clock(struct device *dev,
                              int clksrc,
                              unsigned long req_freq)
{
        struct sm501_devdata *sm = dev_get_drvdata(dev);
        unsigned long mode = smc501_readl(sm->regs + SM501_POWER_MODE_CONTROL);
        unsigned long gate = smc501_readl(sm->regs + SM501_CURRENT_GATE);
        unsigned long clock = smc501_readl(sm->regs + SM501_CURRENT_CLOCK);
        unsigned int pll_reg = 0;
        unsigned long sm501_freq; /* the actual frequency achieved */
        u64 reg;

        struct sm501_clock to;

        /* find achivable discrete frequency and setup register value
         * accordingly, V2XCLK, MCLK and M1XCLK are the same P2XCLK
         * has an extra bit for the divider */

        switch (clksrc) {
        case SM501_CLOCK_P2XCLK:
                /* This clock is divided in half so to achieve the
                 * requested frequency the value must be multiplied by
                 * 2. This clock also has an additional pre divisor */

                if (sm->rev >= 0xC0) {
                        /* SM502 -> use the programmable PLL */
                        sm501_freq = (sm501_calc_pll(2 * req_freq,
                                                     &to, 5) / 2);
                        reg = to.shift & 0x07;/* bottom 3 bits are shift */
                        if (to.divider == 3)
                                reg |= 0x08; /* /3 divider required */
                        else if (to.divider == 5)
                                reg |= 0x10; /* /5 divider required */
                        reg |= 0x40; /* select the programmable PLL */
                        pll_reg = 0x20000 | (to.k << 15) | (to.n << 8) | to.m;
                } else {
                        sm501_freq = (sm501_select_clock(2 * req_freq,
                                                         &to, 5) / 2);
                        reg = to.shift & 0x07;/* bottom 3 bits are shift */
                        if (to.divider == 3)
                                reg |= 0x08; /* /3 divider required */
                        else if (to.divider == 5)
                                reg |= 0x10; /* /5 divider required */
                        if (to.mclk != 288000000)
                                reg |= 0x20; /* which mclk pll is source */
                }
                break;

        case SM501_CLOCK_V2XCLK:
                /* This clock is divided in half so to achieve the
                 * requested frequency the value must be multiplied by 2. */

                sm501_freq = (sm501_select_clock(2 * req_freq, &to, 3) / 2);
                reg=to.shift & 0x07;    /* bottom 3 bits are shift */
                if (to.divider == 3)
                        reg |= 0x08;    /* /3 divider required */
                if (to.mclk != 288000000)
                        reg |= 0x10;    /* which mclk pll is source */
                break;

        case SM501_CLOCK_MCLK:
        case SM501_CLOCK_M1XCLK:
                /* These clocks are the same and not further divided */

                sm501_freq = sm501_select_clock( req_freq, &to, 3);
                reg=to.shift & 0x07;    /* bottom 3 bits are shift */
                if (to.divider == 3)
                        reg |= 0x08;    /* /3 divider required */
                if (to.mclk != 288000000)
                        reg |= 0x10;    /* which mclk pll is source */
                break;

        default:
                return 0; /* this is bad */
        }

        mutex_lock(&sm->clock_lock);

        mode = smc501_readl(sm->regs + SM501_POWER_MODE_CONTROL);
        gate = smc501_readl(sm->regs + SM501_CURRENT_GATE);
        clock = smc501_readl(sm->regs + SM501_CURRENT_CLOCK);

        clock = clock & ~(0xFF << clksrc);
        clock |= reg<<clksrc;

        mode &= 3;      /* find current mode */

        switch (mode) {
        case 1:
                smc501_writel(gate, sm->regs + SM501_POWER_MODE_0_GATE);
                smc501_writel(clock, sm->regs + SM501_POWER_MODE_0_CLOCK);
                mode = 0;
                break;
        case 2:
        case 0:
                smc501_writel(gate, sm->regs + SM501_POWER_MODE_1_GATE);
                smc501_writel(clock, sm->regs + SM501_POWER_MODE_1_CLOCK);
                mode = 1;
                break;

        default:
                mutex_unlock(&sm->clock_lock);
                return -1;
        }

        smc501_writel(mode, sm->regs + SM501_POWER_MODE_CONTROL);

        if (pll_reg)
                smc501_writel(pll_reg,
                                sm->regs + SM501_PROGRAMMABLE_PLL_CONTROL);

        sm501_sync_regs(sm);

        dev_dbg(sm->dev, "gate %08lx, clock %08lx, mode %08lx\n",
                gate, clock, mode);

        sm501_mdelay(sm, 16);
        mutex_unlock(&sm->clock_lock);

        sm501_dump_clk(sm);

        return sm501_freq;
}

EXPORT_SYMBOL_GPL(sm501_set_clock);

static struct sm501_device *to_sm_device(struct platform_device *pdev)
{
        return container_of(pdev, struct sm501_device, pdev);
}

/* sm501_device_release
 *
 * A release function for the platform devices we create to allow us to
 * free any items we allocated
*/

static void sm501_device_release(struct device *dev)
{
        kfree(to_sm_device(to_platform_device(dev)));
}

/* sm501_create_subdev
 *
 * Create a skeleton platform device with resources for passing to a
 * sub-driver
*/

static struct platform_device *
sm501_create_subdev(struct sm501_devdata *sm, char *name,
                    unsigned int res_count, unsigned int platform_data_size)
{
        struct sm501_device *smdev;

        smdev = kzalloc(sizeof(struct sm501_device) +
                        (sizeof(struct resource) * res_count) +
                        platform_data_size, GFP_KERNEL);
        if (!smdev)
                return NULL;

        smdev->pdev.dev.release = sm501_device_release;

        smdev->pdev.name = name;
        smdev->pdev.id = sm->pdev_id;
        smdev->pdev.dev.parent = sm->dev;
        smdev->pdev.dev.coherent_dma_mask = 0xffffffff;

        if (res_count) {
                smdev->pdev.resource = (struct resource *)(smdev+1);
                smdev->pdev.num_resources = res_count;
        }
        if (platform_data_size)
                smdev->pdev.dev.platform_data = (void *)(smdev+1);

        return &smdev->pdev;
}

/* sm501_register_device
 *
 * Register a platform device created with sm501_create_subdev()
*/

static int sm501_register_device(struct sm501_devdata *sm,
                                 struct platform_device *pdev)
{
        struct sm501_device *smdev = to_sm_device(pdev);
        int ptr;
        int ret;

        for (ptr = 0; ptr < pdev->num_resources; ptr++) {
                printk(KERN_DEBUG "%s[%d] %pR\n",
                       pdev->name, ptr, &pdev->resource[ptr]);
        }

        ret = platform_device_register(pdev);

        if (ret >= 0) {
                dev_dbg(sm->dev, "registered %s\n", pdev->name);
                list_add_tail(&smdev->list, &sm->devices);
        } else
                dev_err(sm->dev, "error registering %s (%d)\n",
                        pdev->name, ret);

        return ret;
}

/* sm501_create_subio
 *
 * Fill in an IO resource for a sub device
*/

static void sm501_create_subio(struct sm501_devdata *sm,
                               struct resource *res,
                               resource_size_t offs,
                               resource_size_t size)
{
        res->flags = IORESOURCE_MEM;
        res->parent = sm->io_res;
        res->start = sm->io_res->start + offs;
        res->end = res->start + size - 1;
}

/* sm501_create_mem
 *
 * Fill in an MEM resource for a sub device
*/

static void sm501_create_mem(struct sm501_devdata *sm,
                             struct resource *res,
                             resource_size_t *offs,
                             resource_size_t size)
{
        *offs -= size;          /* adjust memory size */

        res->flags = IORESOURCE_MEM;
        res->parent = sm->mem_res;
        res->start = sm->mem_res->start + *offs;
        res->end = res->start + size - 1;
}

/* sm501_create_irq
 *
 * Fill in an IRQ resource for a sub device
*/

static void sm501_create_irq(struct sm501_devdata *sm,
                             struct resource *res)
{
        res->flags = IORESOURCE_IRQ;
        res->parent = NULL;
        res->start = res->end = sm->irq;
}

static int sm501_register_usbhost(struct sm501_devdata *sm,
                                  resource_size_t *mem_avail)
{
        struct platform_device *pdev;

        pdev = sm501_create_subdev(sm, "sm501-usb", 3, 0);
        if (!pdev)
                return -ENOMEM;

        sm501_create_subio(sm, &pdev->resource[0], 0x40000, 0x20000);
        sm501_create_mem(sm, &pdev->resource[1], mem_avail, 256*1024);
        sm501_create_irq(sm, &pdev->resource[2]);

        return sm501_register_device(sm, pdev);
}

static void sm501_setup_uart_data(struct sm501_devdata *sm,
                                  struct plat_serial8250_port *uart_data,
                                  unsigned int offset)
{
        uart_data->membase = sm->regs + offset;
        uart_data->mapbase = sm->io_res->start + offset;
        uart_data->iotype = UPIO_MEM;
        uart_data->irq = sm->irq;
        uart_data->flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_SHARE_IRQ;
        uart_data->regshift = 2;
        uart_data->uartclk = (9600 * 16);
}

static int sm501_register_uart(struct sm501_devdata *sm, int devices)
{
        struct platform_device *pdev;
        struct plat_serial8250_port *uart_data;

        pdev = sm501_create_subdev(sm, "serial8250", 0,
                                   sizeof(struct plat_serial8250_port) * 3);
        if (!pdev)
                return -ENOMEM;

        uart_data = dev_get_platdata(&pdev->dev);

        if (devices & SM501_USE_UART0) {
                sm501_setup_uart_data(sm, uart_data++, 0x30000);
                sm501_unit_power(sm->dev, SM501_GATE_UART0, 1);
                sm501_modify_reg(sm->dev, SM501_IRQ_MASK, 1 << 12, 0);
                sm501_modify_reg(sm->dev, SM501_GPIO63_32_CONTROL, 0x01e0, 0);
        }
        if (devices & SM501_USE_UART1) {
                sm501_setup_uart_data(sm, uart_data++, 0x30020);
                sm501_unit_power(sm->dev, SM501_GATE_UART1, 1);
                sm501_modify_reg(sm->dev, SM501_IRQ_MASK, 1 << 13, 0);
                sm501_modify_reg(sm->dev, SM501_GPIO63_32_CONTROL, 0x1e00, 0);
        }

        pdev->id = PLAT8250_DEV_SM501;

        return sm501_register_device(sm, pdev);
}

static int sm501_register_display(struct sm501_devdata *sm,
                                  resource_size_t *mem_avail)
{
        struct platform_device *pdev;

        pdev = sm501_create_subdev(sm, "sm501-fb", 4, 0);
        if (!pdev)
                return -ENOMEM;

        sm501_create_subio(sm, &pdev->resource[0], 0x80000, 0x10000);
        sm501_create_subio(sm, &pdev->resource[1], 0x100000, 0x50000);
        sm501_create_mem(sm, &pdev->resource[2], mem_avail, *mem_avail);
        sm501_create_irq(sm, &pdev->resource[3]);

        return sm501_register_device(sm, pdev);
}

#ifdef CONFIG_MFD_SM501_GPIO

static inline struct sm501_devdata *sm501_gpio_to_dev(struct sm501_gpio *gpio)
{
        return container_of(gpio, struct sm501_devdata, gpio);
}

static int sm501_gpio_get(struct gpio_chip *chip, unsigned offset)

{
        struct sm501_gpio_chip *smgpio = gpiochip_get_data(chip);
        unsigned long result;

        result = smc501_readl(smgpio->regbase + SM501_GPIO_DATA_LOW);
        result >>= offset;

        return result & 1UL;
}

static void sm501_gpio_ensure_gpio(struct sm501_gpio_chip *smchip,
                                   unsigned long bit)
{
        unsigned long ctrl;

        /* check and modify if this pin is not set as gpio. */

        if (smc501_readl(smchip->control) & bit) {
                dev_info(sm501_gpio_to_dev(smchip->ourgpio)->dev,
                         "changing mode of gpio, bit %08lx\n", bit);

                ctrl = smc501_readl(smchip->control);
                ctrl &= ~bit;
                smc501_writel(ctrl, smchip->control);

                sm501_sync_regs(sm501_gpio_to_dev(smchip->ourgpio));
        }
}

static int sm501_gpio_set(struct gpio_chip *chip, unsigned int offset,
                          int value)

{
        struct sm501_gpio_chip *smchip = gpiochip_get_data(chip);
        struct sm501_gpio *smgpio = smchip->ourgpio;
        unsigned long bit = BIT(offset);
        void __iomem *regs = smchip->regbase;
        unsigned long save;
        unsigned long val;

        dev_dbg(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d)\n",
                __func__, chip, offset);

        spin_lock_irqsave(&smgpio->lock, save);

        val = smc501_readl(regs + SM501_GPIO_DATA_LOW) & ~bit;
        if (value)
                val |= bit;
        smc501_writel(val, regs);

        sm501_sync_regs(sm501_gpio_to_dev(smgpio));
        sm501_gpio_ensure_gpio(smchip, bit);

        spin_unlock_irqrestore(&smgpio->lock, save);

        return 0;
}

static int sm501_gpio_input(struct gpio_chip *chip, unsigned offset)
{
        struct sm501_gpio_chip *smchip = gpiochip_get_data(chip);
        struct sm501_gpio *smgpio = smchip->ourgpio;
        void __iomem *regs = smchip->regbase;
        unsigned long bit = BIT(offset);
        unsigned long save;
        unsigned long ddr;

        dev_dbg(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d)\n",
                __func__, chip, offset);

        spin_lock_irqsave(&smgpio->lock, save);

        ddr = smc501_readl(regs + SM501_GPIO_DDR_LOW);
        smc501_writel(ddr & ~bit, regs + SM501_GPIO_DDR_LOW);

        sm501_sync_regs(sm501_gpio_to_dev(smgpio));
        sm501_gpio_ensure_gpio(smchip, bit);

        spin_unlock_irqrestore(&smgpio->lock, save);

        return 0;
}

static int sm501_gpio_output(struct gpio_chip *chip,
                             unsigned offset, int value)
{
        struct sm501_gpio_chip *smchip = gpiochip_get_data(chip);
        struct sm501_gpio *smgpio = smchip->ourgpio;
        unsigned long bit = BIT(offset);
        void __iomem *regs = smchip->regbase;
        unsigned long save;
        unsigned long val;
        unsigned long ddr;

        dev_dbg(sm501_gpio_to_dev(smgpio)->dev, "%s(%p,%d,%d)\n",
                __func__, chip, offset, value);

        spin_lock_irqsave(&smgpio->lock, save);

        val = smc501_readl(regs + SM501_GPIO_DATA_LOW);
        if (value)
                val |= bit;
        else
                val &= ~bit;
        smc501_writel(val, regs);

        ddr = smc501_readl(regs + SM501_GPIO_DDR_LOW);
        smc501_writel(ddr | bit, regs + SM501_GPIO_DDR_LOW);

        sm501_sync_regs(sm501_gpio_to_dev(smgpio));
        smc501_writel(val, regs + SM501_GPIO_DATA_LOW);

        sm501_sync_regs(sm501_gpio_to_dev(smgpio));
        spin_unlock_irqrestore(&smgpio->lock, save);

        return 0;
}

static const struct gpio_chip gpio_chip_template = {
        .ngpio                  = 32,
        .direction_input        = sm501_gpio_input,
        .direction_output       = sm501_gpio_output,
        .set                    = sm501_gpio_set,
        .get                    = sm501_gpio_get,
};

static int sm501_gpio_register_chip(struct sm501_devdata *sm,
                                              struct sm501_gpio *gpio,
                                              struct sm501_gpio_chip *chip)
{
        struct sm501_platdata *pdata = sm->platdata;
        struct gpio_chip *gchip = &chip->gpio;
        int base = pdata->gpio_base;

        chip->gpio = gpio_chip_template;

        if (chip == &gpio->high) {
                if (base > 0)
                        base += 32;
                chip->regbase = gpio->regs + SM501_GPIO_DATA_HIGH;
                chip->control = sm->regs + SM501_GPIO63_32_CONTROL;
                gchip->label  = "SM501-HIGH";
        } else {
                chip->regbase = gpio->regs + SM501_GPIO_DATA_LOW;
                chip->control = sm->regs + SM501_GPIO31_0_CONTROL;
                gchip->label  = "SM501-LOW";
        }

        gchip->base   = base;
        chip->ourgpio = gpio;

        return gpiochip_add_data(gchip, chip);
}

static int sm501_register_gpio(struct sm501_devdata *sm)
{
        struct sm501_gpio *gpio = &sm->gpio;
        resource_size_t iobase = sm->io_res->start + SM501_GPIO;
        int ret;

        dev_dbg(sm->dev, "registering gpio block %08llx\n",
                (unsigned long long)iobase);

        spin_lock_init(&gpio->lock);

        gpio->regs_res = request_mem_region(iobase, 0x20, "sm501-gpio");
        if (!gpio->regs_res) {
                dev_err(sm->dev, "gpio: failed to request region\n");
                return -ENXIO;
        }

        gpio->regs = ioremap(iobase, 0x20);
        if (!gpio->regs) {
                dev_err(sm->dev, "gpio: failed to remap registers\n");
                ret = -ENXIO;
                goto err_claimed;
        }

        /* Register both our chips. */

        ret = sm501_gpio_register_chip(sm, gpio, &gpio->low);
        if (ret) {
                dev_err(sm->dev, "failed to add low chip\n");
                goto err_mapped;
        }

        ret = sm501_gpio_register_chip(sm, gpio, &gpio->high);
        if (ret) {
                dev_err(sm->dev, "failed to add high chip\n");
                goto err_low_chip;
        }

        gpio->registered = 1;

        return 0;

 err_low_chip:
        gpiochip_remove(&gpio->low.gpio);

 err_mapped:
        iounmap(gpio->regs);

 err_claimed:
        release_mem_region(iobase, 0x20);

        return ret;
}

static void sm501_gpio_remove(struct sm501_devdata *sm)
{
        struct sm501_gpio *gpio = &sm->gpio;
        resource_size_t iobase = sm->io_res->start + SM501_GPIO;

        if (!sm->gpio.registered)
                return;

        gpiochip_remove(&gpio->low.gpio);
        gpiochip_remove(&gpio->high.gpio);

        iounmap(gpio->regs);
        release_mem_region(iobase, 0x20);
}

static inline int sm501_gpio_isregistered(struct sm501_devdata *sm)
{
        return sm->gpio.registered;
}
#else
static inline int sm501_register_gpio(struct sm501_devdata *sm)
{
        return 0;
}

static inline void sm501_gpio_remove(struct sm501_devdata *sm)
{
}

static inline int sm501_gpio_isregistered(struct sm501_devdata *sm)
{
        return 0;
}
#endif

static int sm501_register_gpio_i2c_instance(struct sm501_devdata *sm,
                                            struct sm501_platdata_gpio_i2c *iic)
{
        struct i2c_gpio_platform_data *icd;
        struct platform_device *pdev;
        struct gpiod_lookup_table *lookup;

        pdev = sm501_create_subdev(sm, "i2c-gpio", 0,
                                   sizeof(struct i2c_gpio_platform_data));
        if (!pdev)
                return -ENOMEM;

        /* Create a gpiod lookup using gpiochip-local offsets */
        lookup = devm_kzalloc(&pdev->dev, struct_size(lookup, table, 3),
                              GFP_KERNEL);
        if (!lookup)
                return -ENOMEM;

        lookup->dev_id = "i2c-gpio";
        lookup->table[0] = (struct gpiod_lookup)
                GPIO_LOOKUP_IDX(iic->pin_sda < 32 ? "SM501-LOW" : "SM501-HIGH",
                                iic->pin_sda % 32, NULL, 0,
                                GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN);
        lookup->table[1] = (struct gpiod_lookup)
                GPIO_LOOKUP_IDX(iic->pin_scl < 32 ? "SM501-LOW" : "SM501-HIGH",
                                iic->pin_scl % 32, NULL, 1,
                                GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN);
        gpiod_add_lookup_table(lookup);

        icd = dev_get_platdata(&pdev->dev);
        icd->timeout = iic->timeout;
        icd->udelay = iic->udelay;

        /* note, we can't use either of the pin numbers, as the i2c-gpio
         * driver uses the platform.id field to generate the bus number
         * to register with the i2c core; The i2c core doesn't have enough
         * entries to deal with anything we currently use.
        */

        pdev->id = iic->bus_num;

        dev_info(sm->dev, "registering i2c-%d: sda=%d, scl=%d\n",
                 iic->bus_num,
                 iic->pin_sda, iic->pin_scl);

        return sm501_register_device(sm, pdev);
}

static int sm501_register_gpio_i2c(struct sm501_devdata *sm,
                                   struct sm501_platdata *pdata)
{
        struct sm501_platdata_gpio_i2c *iic = pdata->gpio_i2c;
        int index;
        int ret;

        for (index = 0; index < pdata->gpio_i2c_nr; index++, iic++) {
                ret = sm501_register_gpio_i2c_instance(sm, iic);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

/* dbg_regs_show
 *
 * Debug attribute to attach to parent device to show core registers
*/

static ssize_t dbg_regs_show(struct device *dev,
                             struct device_attribute *attr, char *buff)
{
        struct sm501_devdata *sm = dev_get_drvdata(dev) ;
        unsigned int reg;
        char *ptr = buff;
        int ret;

        for (reg = 0x00; reg < 0x70; reg += 4) {
                ret = sprintf(ptr, "%08x = %08x\n",
                              reg, smc501_readl(sm->regs + reg));
                ptr += ret;
        }

        return ptr - buff;
}


static DEVICE_ATTR_RO(dbg_regs);

/* sm501_init_reg
 *
 * Helper function for the init code to setup a register
 *
 * clear the bits which are set in r->mask, and then set
 * the bits set in r->set.
*/

static inline void sm501_init_reg(struct sm501_devdata *sm,
                                  unsigned long reg,
                                  struct sm501_reg_init *r)
{
        unsigned long tmp;

        tmp = smc501_readl(sm->regs + reg);
        tmp &= ~r->mask;
        tmp |= r->set;
        smc501_writel(tmp, sm->regs + reg);
}

/* sm501_init_regs
 *
 * Setup core register values
*/

static void sm501_init_regs(struct sm501_devdata *sm,
                            struct sm501_initdata *init)
{
        sm501_misc_control(sm->dev,
                           init->misc_control.set,
                           init->misc_control.mask);

        sm501_init_reg(sm, SM501_MISC_TIMING, &init->misc_timing);
        sm501_init_reg(sm, SM501_GPIO31_0_CONTROL, &init->gpio_low);
        sm501_init_reg(sm, SM501_GPIO63_32_CONTROL, &init->gpio_high);

        if (init->m1xclk) {
                dev_info(sm->dev, "setting M1XCLK to %ld\n", init->m1xclk);
                sm501_set_clock(sm->dev, SM501_CLOCK_M1XCLK, init->m1xclk);
        }

        if (init->mclk) {
                dev_info(sm->dev, "setting MCLK to %ld\n", init->mclk);
                sm501_set_clock(sm->dev, SM501_CLOCK_MCLK, init->mclk);
        }

}

/* Check the PLL sources for the M1CLK and M1XCLK
 *
 * If the M1CLK and M1XCLKs are not sourced from the same PLL, then
 * there is a risk (see errata AB-5) that the SM501 will cease proper
 * function. If this happens, then it is likely the SM501 will
 * hang the system.
*/

static int sm501_check_clocks(struct sm501_devdata *sm)
{
        unsigned long pwrmode = smc501_readl(sm->regs + SM501_CURRENT_CLOCK);
        unsigned long msrc = (pwrmode & SM501_POWERMODE_M_SRC);
        unsigned long m1src = (pwrmode & SM501_POWERMODE_M1_SRC);

        return ((msrc == 0 && m1src != 0) || (msrc != 0 && m1src == 0));
}

static unsigned int sm501_mem_local[] = {
        [0]     = 4*1024*1024,
        [1]     = 8*1024*1024,
        [2]     = 16*1024*1024,
        [3]     = 32*1024*1024,
        [4]     = 64*1024*1024,
        [5]     = 2*1024*1024,
};

/* sm501_init_dev
 *
 * Common init code for an SM501
*/

static int sm501_init_dev(struct sm501_devdata *sm)
{
        struct sm501_initdata *idata;
        struct sm501_platdata *pdata;
        resource_size_t mem_avail;
        unsigned long dramctrl;
        unsigned long devid;
        int ret;

        mutex_init(&sm->clock_lock);
        spin_lock_init(&sm->reg_lock);

        INIT_LIST_HEAD(&sm->devices);

        devid = smc501_readl(sm->regs + SM501_DEVICEID);

        if ((devid & SM501_DEVICEID_IDMASK) != SM501_DEVICEID_SM501) {
                dev_err(sm->dev, "incorrect device id %08lx\n", devid);
                return -EINVAL;
        }

        /* disable irqs */
        smc501_writel(0, sm->regs + SM501_IRQ_MASK);

        dramctrl = smc501_readl(sm->regs + SM501_DRAM_CONTROL);
        mem_avail = sm501_mem_local[(dramctrl >> 13) & 0x7];

        dev_info(sm->dev, "SM501 At %p: Version %08lx, %ld Mb, IRQ %d\n",
                 sm->regs, devid, (unsigned long)mem_avail >> 20, sm->irq);

        sm->rev = devid & SM501_DEVICEID_REVMASK;

        sm501_dump_gate(sm);

        ret = device_create_file(sm->dev, &dev_attr_dbg_regs);
        if (ret)
                dev_err(sm->dev, "failed to create debug regs file\n");

        sm501_dump_clk(sm);

        /* check to see if we have some device initialisation */

        pdata = sm->platdata;
        idata = pdata ? pdata->init : NULL;

        if (idata) {
                sm501_init_regs(sm, idata);

                if (idata->devices & SM501_USE_USB_HOST)
                        sm501_register_usbhost(sm, &mem_avail);
                if (idata->devices & (SM501_USE_UART0 | SM501_USE_UART1))
                        sm501_register_uart(sm, idata->devices);
                if (idata->devices & SM501_USE_GPIO)
                        sm501_register_gpio(sm);
        }

        if (pdata && pdata->gpio_i2c && pdata->gpio_i2c_nr > 0) {
                if (!sm501_gpio_isregistered(sm))
                        dev_err(sm->dev, "no gpio available for i2c gpio.\n");
                else
                        sm501_register_gpio_i2c(sm, pdata);
        }

        ret = sm501_check_clocks(sm);
        if (ret) {
                dev_err(sm->dev, "M1X and M clocks sourced from different "
                                        "PLLs\n");
                return -EINVAL;
        }

        /* always create a framebuffer */
        sm501_register_display(sm, &mem_avail);

        return 0;
}

static int sm501_plat_probe(struct platform_device *dev)
{
        struct sm501_devdata *sm;
        int ret;

        sm = kzalloc_obj(*sm);
        if (!sm) {
                ret = -ENOMEM;
                goto err1;
        }

        sm->dev = &dev->dev;
        sm->pdev_id = dev->id;
        sm->platdata = dev_get_platdata(&dev->dev);

        ret = platform_get_irq(dev, 0);
        if (ret < 0)
                goto err_res;
        sm->irq = ret;

        sm->io_res = platform_get_resource(dev, IORESOURCE_MEM, 1);
        sm->mem_res = platform_get_resource(dev, IORESOURCE_MEM, 0);
        if (!sm->io_res || !sm->mem_res) {
                dev_err(&dev->dev, "failed to get IO resource\n");
                ret = -ENOENT;
                goto err_res;
        }

        sm->regs_claim = request_mem_region(sm->io_res->start,
                                            0x100, "sm501");
        if (!sm->regs_claim) {
                dev_err(&dev->dev, "cannot claim registers\n");
                ret = -EBUSY;
                goto err_res;
        }

        platform_set_drvdata(dev, sm);

        sm->regs = ioremap(sm->io_res->start, resource_size(sm->io_res));
        if (!sm->regs) {
                dev_err(&dev->dev, "cannot remap registers\n");
                ret = -EIO;
                goto err_claim;
        }

        ret = sm501_init_dev(sm);
        if (ret)
                goto err_unmap;

        return 0;

 err_unmap:
        iounmap(sm->regs);
 err_claim:
        release_mem_region(sm->io_res->start, 0x100);
 err_res:
        kfree(sm);
 err1:
        return ret;

}

/* power management support */

static void sm501_set_power(struct sm501_devdata *sm, int on)
{
        struct sm501_platdata *pd = sm->platdata;

        if (!pd)
                return;

        if (pd->get_power) {
                if (pd->get_power(sm->dev) == on) {
                        dev_dbg(sm->dev, "is already %d\n", on);
                        return;
                }
        }

        if (pd->set_power) {
                dev_dbg(sm->dev, "setting power to %d\n", on);

                pd->set_power(sm->dev, on);
                sm501_mdelay(sm, 10);
        }
}

static int sm501_plat_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct sm501_devdata *sm = platform_get_drvdata(pdev);

        sm->in_suspend = 1;
        sm->pm_misc = smc501_readl(sm->regs + SM501_MISC_CONTROL);

        sm501_dump_regs(sm);

        if (sm->platdata) {
                if (sm->platdata->flags & SM501_FLAG_SUSPEND_OFF)
                        sm501_set_power(sm, 0);
        }

        return 0;
}

static int sm501_plat_resume(struct platform_device *pdev)
{
        struct sm501_devdata *sm = platform_get_drvdata(pdev);

        sm501_set_power(sm, 1);

        sm501_dump_regs(sm);
        sm501_dump_gate(sm);
        sm501_dump_clk(sm);

        /* check to see if we are in the same state as when suspended */

        if (smc501_readl(sm->regs + SM501_MISC_CONTROL) != sm->pm_misc) {
                dev_info(sm->dev, "SM501_MISC_CONTROL changed over sleep\n");
                smc501_writel(sm->pm_misc, sm->regs + SM501_MISC_CONTROL);

                /* our suspend causes the controller state to change,
                 * either by something attempting setup, power loss,
                 * or an external reset event on power change */

                if (sm->platdata && sm->platdata->init) {
                        sm501_init_regs(sm, sm->platdata->init);
                }
        }

        /* dump our state from resume */

        sm501_dump_regs(sm);
        sm501_dump_clk(sm);

        sm->in_suspend = 0;

        return 0;
}

/* Initialisation data for PCI devices */

static struct sm501_initdata sm501_pci_initdata = {
        .gpio_high      = {
                .set    = 0x3F000000,           /* 24bit panel */
                .mask   = 0x0,
        },
        .misc_timing    = {
                .set    = 0x010100,             /* SDRAM timing */
                .mask   = 0x1F1F00,
        },
        .misc_control   = {
                .set    = SM501_MISC_PNL_24BIT,
                .mask   = 0,
        },

        .devices        = SM501_USE_ALL,

        /* Errata AB-3 says that 72MHz is the fastest available
         * for 33MHZ PCI with proper bus-mastering operation */

        .mclk           = 72 * MHZ,
        .m1xclk         = 144 * MHZ,
};

static struct sm501_platdata_fbsub sm501_pdata_fbsub = {
        .flags          = (SM501FB_FLAG_USE_INIT_MODE |
                           SM501FB_FLAG_USE_HWCURSOR |
                           SM501FB_FLAG_USE_HWACCEL |
                           SM501FB_FLAG_DISABLE_AT_EXIT),
};

static struct sm501_platdata_fb sm501_fb_pdata = {
        .fb_route       = SM501_FB_OWN,
        .fb_crt         = &sm501_pdata_fbsub,
        .fb_pnl         = &sm501_pdata_fbsub,
};

static struct sm501_platdata sm501_pci_platdata = {
        .init           = &sm501_pci_initdata,
        .fb             = &sm501_fb_pdata,
        .gpio_base      = -1,
};

static int sm501_pci_probe(struct pci_dev *dev,
                                     const struct pci_device_id *id)
{
        struct sm501_devdata *sm;
        int err;

        sm = kzalloc_obj(*sm);
        if (!sm) {
                err = -ENOMEM;
                goto err1;
        }

        /* set a default set of platform data */
        dev->dev.platform_data = sm->platdata = &sm501_pci_platdata;

        /* set a hopefully unique id for our child platform devices */
        sm->pdev_id = 32 + dev->devfn;

        pci_set_drvdata(dev, sm);

        err = pci_enable_device(dev);
        if (err) {
                dev_err(&dev->dev, "cannot enable device\n");
                goto err2;
        }

        sm->dev = &dev->dev;
        sm->irq = dev->irq;

#ifdef __BIG_ENDIAN
        /* if the system is big-endian, we most probably have a
         * translation in the IO layer making the PCI bus little endian
         * so make the framebuffer swapped pixels */

        sm501_fb_pdata.flags |= SM501_FBPD_SWAP_FB_ENDIAN;
#endif

        /* check our resources */

        if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM)) {
                dev_err(&dev->dev, "region #0 is not memory?\n");
                err = -EINVAL;
                goto err3;
        }

        if (!(pci_resource_flags(dev, 1) & IORESOURCE_MEM)) {
                dev_err(&dev->dev, "region #1 is not memory?\n");
                err = -EINVAL;
                goto err3;
        }

        /* make our resources ready for sharing */

        sm->io_res = &dev->resource[1];
        sm->mem_res = &dev->resource[0];

        sm->regs_claim = request_mem_region(sm->io_res->start,
                                            0x100, "sm501");
        if (!sm->regs_claim) {
                dev_err(&dev->dev, "cannot claim registers\n");
                err= -EBUSY;
                goto err3;
        }

        sm->regs = pci_ioremap_bar(dev, 1);
        if (!sm->regs) {
                dev_err(&dev->dev, "cannot remap registers\n");
                err = -EIO;
                goto err4;
        }

        sm501_init_dev(sm);
        return 0;

 err4:
        release_mem_region(sm->io_res->start, 0x100);
 err3:
        pci_disable_device(dev);
 err2:
        kfree(sm);
 err1:
        return err;
}

static void sm501_remove_sub(struct sm501_devdata *sm,
                             struct sm501_device *smdev)
{
        list_del(&smdev->list);
        platform_device_unregister(&smdev->pdev);
}

static void sm501_dev_remove(struct sm501_devdata *sm)
{
        struct sm501_device *smdev, *tmp;

        list_for_each_entry_safe(smdev, tmp, &sm->devices, list)
                sm501_remove_sub(sm, smdev);

        device_remove_file(sm->dev, &dev_attr_dbg_regs);

        sm501_gpio_remove(sm);
}

static void sm501_pci_remove(struct pci_dev *dev)
{
        struct sm501_devdata *sm = pci_get_drvdata(dev);

        sm501_dev_remove(sm);
        iounmap(sm->regs);

        release_mem_region(sm->io_res->start, 0x100);

        pci_disable_device(dev);
}

static void sm501_plat_remove(struct platform_device *dev)
{
        struct sm501_devdata *sm = platform_get_drvdata(dev);

        sm501_dev_remove(sm);
        iounmap(sm->regs);

        release_mem_region(sm->io_res->start, 0x100);
}

static const struct pci_device_id sm501_pci_tbl[] = {
        { 0x126f, 0x0501, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
        { 0, },
};

MODULE_DEVICE_TABLE(pci, sm501_pci_tbl);

static struct pci_driver sm501_pci_driver = {
        .name           = "sm501",
        .id_table       = sm501_pci_tbl,
        .probe          = sm501_pci_probe,
        .remove         = sm501_pci_remove,
};

MODULE_ALIAS("platform:sm501");

static const struct of_device_id of_sm501_match_tbl[] = {
        { .compatible = "smi,sm501", },
        { /* end */ }
};
MODULE_DEVICE_TABLE(of, of_sm501_match_tbl);

static struct platform_driver sm501_plat_driver = {
        .driver         = {
                .name   = "sm501",
                .of_match_table = of_sm501_match_tbl,
        },
        .probe          = sm501_plat_probe,
        .remove         = sm501_plat_remove,
        .suspend        = pm_sleep_ptr(sm501_plat_suspend),
        .resume         = pm_sleep_ptr(sm501_plat_resume),
};

static int __init sm501_base_init(void)
{
        int ret;

        ret = platform_driver_register(&sm501_plat_driver);
        if (ret < 0)
                return ret;

        return pci_register_driver(&sm501_pci_driver);
}

static void __exit sm501_base_exit(void)
{
        platform_driver_unregister(&sm501_plat_driver);
        pci_unregister_driver(&sm501_pci_driver);
}

module_init(sm501_base_init);
module_exit(sm501_base_exit);

MODULE_DESCRIPTION("SM501 Core Driver");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, Vincent Sanders");
MODULE_LICENSE("GPL v2");