// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
// Copyright(c) 2015-17 Intel Corporation.

/*
 * Cadence SoundWire Master module
 * Used by Master driver
 */

#include <linux/cleanup.h>
#include <linux/crc8.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/debugfs.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/pm_runtime.h>
#include <linux/soundwire/sdw_registers.h>
#include <linux/soundwire/sdw.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <linux/workqueue.h>
#include "bus.h"
#include "cadence_master.h"

static int interrupt_mask;
module_param_named(cnds_mcp_int_mask, interrupt_mask, int, 0444);
MODULE_PARM_DESC(cdns_mcp_int_mask, "Cadence MCP IntMask");

#define CDNS_MCP_CONFIG                         0x0
#define CDNS_MCP_CONFIG_BUS_REL                 BIT(6)

#define CDNS_IP_MCP_CONFIG                      0x0 /* IP offset added at run-time */

#define CDNS_IP_MCP_CONFIG_MCMD_RETRY           GENMASK(27, 24)
#define CDNS_IP_MCP_CONFIG_MPREQ_DELAY          GENMASK(20, 16)
#define CDNS_IP_MCP_CONFIG_MMASTER              BIT(7)
#define CDNS_IP_MCP_CONFIG_SNIFFER              BIT(5)
#define CDNS_IP_MCP_CONFIG_CMD                  BIT(3)
#define CDNS_IP_MCP_CONFIG_OP                   GENMASK(2, 0)
#define CDNS_IP_MCP_CONFIG_OP_NORMAL            0

#define CDNS_MCP_CONTROL                        0x4

#define CDNS_MCP_CONTROL_CMD_RST                BIT(7)
#define CDNS_MCP_CONTROL_SOFT_RST               BIT(6)
#define CDNS_MCP_CONTROL_HW_RST                 BIT(4)
#define CDNS_MCP_CONTROL_CLK_STOP_CLR           BIT(2)

#define CDNS_IP_MCP_CONTROL                     0x4  /* IP offset added at run-time */

#define CDNS_IP_MCP_CONTROL_RST_DELAY           GENMASK(10, 8)
#define CDNS_IP_MCP_CONTROL_SW_RST              BIT(5)
#define CDNS_IP_MCP_CONTROL_CLK_PAUSE           BIT(3)
#define CDNS_IP_MCP_CONTROL_CMD_ACCEPT          BIT(1)
#define CDNS_IP_MCP_CONTROL_BLOCK_WAKEUP        BIT(0)

#define CDNS_IP_MCP_CMDCTRL                     0x8 /* IP offset added at run-time */

#define CDNS_IP_MCP_CMDCTRL_INSERT_PARITY_ERR   BIT(2)

#define CDNS_MCP_SSPSTAT                        0xC
#define CDNS_MCP_FRAME_SHAPE                    0x10
#define CDNS_MCP_FRAME_SHAPE_INIT               0x14
#define CDNS_MCP_FRAME_SHAPE_COL_MASK           GENMASK(2, 0)
#define CDNS_MCP_FRAME_SHAPE_ROW_MASK           GENMASK(7, 3)

#define CDNS_MCP_CONFIG_UPDATE                  0x18
#define CDNS_MCP_CONFIG_UPDATE_BIT              BIT(0)

#define CDNS_MCP_PHYCTRL                        0x1C
#define CDNS_MCP_SSP_CTRL0                      0x20
#define CDNS_MCP_SSP_CTRL1                      0x28
#define CDNS_MCP_CLK_CTRL0                      0x30
#define CDNS_MCP_CLK_CTRL1                      0x38
#define CDNS_MCP_CLK_MCLKD_MASK         GENMASK(7, 0)

#define CDNS_MCP_STAT                           0x40

#define CDNS_MCP_STAT_ACTIVE_BANK               BIT(20)
#define CDNS_MCP_STAT_CLK_STOP                  BIT(16)

#define CDNS_MCP_INTSTAT                        0x44
#define CDNS_MCP_INTMASK                        0x48

#define CDNS_MCP_INT_IRQ                        BIT(31)
#define CDNS_MCP_INT_RESERVED1                  GENMASK(30, 17)
#define CDNS_MCP_INT_WAKEUP                     BIT(16)
#define CDNS_MCP_INT_SLAVE_RSVD                 BIT(15)
#define CDNS_MCP_INT_SLAVE_ALERT                BIT(14)
#define CDNS_MCP_INT_SLAVE_ATTACH               BIT(13)
#define CDNS_MCP_INT_SLAVE_NATTACH              BIT(12)
#define CDNS_MCP_INT_SLAVE_MASK                 GENMASK(15, 12)
#define CDNS_MCP_INT_DPINT                      BIT(11)
#define CDNS_MCP_INT_CTRL_CLASH                 BIT(10)
#define CDNS_MCP_INT_DATA_CLASH                 BIT(9)
#define CDNS_MCP_INT_PARITY                     BIT(8)
#define CDNS_MCP_INT_CMD_ERR                    BIT(7)
#define CDNS_MCP_INT_RESERVED2                  GENMASK(6, 4)
#define CDNS_MCP_INT_RX_NE                      BIT(3)
#define CDNS_MCP_INT_RX_WL                      BIT(2)
#define CDNS_MCP_INT_TXE                        BIT(1)
#define CDNS_MCP_INT_TXF                        BIT(0)
#define CDNS_MCP_INT_RESERVED (CDNS_MCP_INT_RESERVED1 | CDNS_MCP_INT_RESERVED2)

#define CDNS_MCP_INTSET                         0x4C

#define CDNS_MCP_SLAVE_STAT                     0x50
#define CDNS_MCP_SLAVE_STAT_MASK                GENMASK(1, 0)

#define CDNS_MCP_SLAVE_INTSTAT0                 0x54
#define CDNS_MCP_SLAVE_INTSTAT1                 0x58
#define CDNS_MCP_SLAVE_INTSTAT_NPRESENT         BIT(0)
#define CDNS_MCP_SLAVE_INTSTAT_ATTACHED         BIT(1)
#define CDNS_MCP_SLAVE_INTSTAT_ALERT            BIT(2)
#define CDNS_MCP_SLAVE_INTSTAT_RESERVED         BIT(3)
#define CDNS_MCP_SLAVE_STATUS_BITS              GENMASK(3, 0)
#define CDNS_MCP_SLAVE_STATUS_NUM               4

#define CDNS_MCP_SLAVE_INTMASK0                 0x5C
#define CDNS_MCP_SLAVE_INTMASK1                 0x60

#define CDNS_MCP_SLAVE_INTMASK0_MASK            GENMASK(31, 0)
#define CDNS_MCP_SLAVE_INTMASK1_MASK            GENMASK(15, 0)

#define CDNS_MCP_PORT_INTSTAT                   0x64
#define CDNS_MCP_PDI_STAT                       0x6C

#define CDNS_MCP_FIFOLEVEL                      0x78
#define CDNS_MCP_FIFOSTAT                       0x7C
#define CDNS_MCP_RX_FIFO_AVAIL                  GENMASK(5, 0)

#define CDNS_IP_MCP_CMD_BASE                    0x80 /* IP offset added at run-time */
#define CDNS_IP_MCP_RESP_BASE                   0x80 /* IP offset added at run-time */
/* FIFO can hold 8 commands */
#define CDNS_MCP_CMD_LEN                        8
#define CDNS_MCP_CMD_WORD_LEN                   0x4

#define CDNS_MCP_CMD_SSP_TAG                    BIT(31)
#define CDNS_MCP_CMD_COMMAND                    GENMASK(30, 28)
#define CDNS_MCP_CMD_DEV_ADDR                   GENMASK(27, 24)
#define CDNS_MCP_CMD_REG_ADDR                   GENMASK(23, 8)
#define CDNS_MCP_CMD_REG_DATA                   GENMASK(7, 0)

#define CDNS_MCP_CMD_READ                       2
#define CDNS_MCP_CMD_WRITE                      3

#define CDNS_MCP_RESP_RDATA                     GENMASK(15, 8)
#define CDNS_MCP_RESP_ACK                       BIT(0)
#define CDNS_MCP_RESP_NACK                      BIT(1)

#define CDNS_DP_SIZE                            128

#define CDNS_DPN_B0_CONFIG(n)                   (0x100 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B0_CH_EN(n)                    (0x104 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B0_SAMPLE_CTRL(n)              (0x108 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B0_OFFSET_CTRL(n)              (0x10C + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B0_HCTRL(n)                    (0x110 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B0_ASYNC_CTRL(n)               (0x114 + CDNS_DP_SIZE * (n))

#define CDNS_DPN_B1_CONFIG(n)                   (0x118 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B1_CH_EN(n)                    (0x11C + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B1_SAMPLE_CTRL(n)              (0x120 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B1_OFFSET_CTRL(n)              (0x124 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B1_HCTRL(n)                    (0x128 + CDNS_DP_SIZE * (n))
#define CDNS_DPN_B1_ASYNC_CTRL(n)               (0x12C + CDNS_DP_SIZE * (n))

#define CDNS_DPN_CONFIG_BPM                     BIT(18)
#define CDNS_DPN_CONFIG_BGC                     GENMASK(17, 16)
#define CDNS_DPN_CONFIG_WL                      GENMASK(12, 8)
#define CDNS_DPN_CONFIG_PORT_DAT                GENMASK(3, 2)
#define CDNS_DPN_CONFIG_PORT_FLOW               GENMASK(1, 0)

#define CDNS_DPN_SAMPLE_CTRL_SI                 GENMASK(15, 0)

#define CDNS_DPN_OFFSET_CTRL_1                  GENMASK(7, 0)
#define CDNS_DPN_OFFSET_CTRL_2                  GENMASK(15, 8)

#define CDNS_DPN_HCTRL_HSTOP                    GENMASK(3, 0)
#define CDNS_DPN_HCTRL_HSTART                   GENMASK(7, 4)
#define CDNS_DPN_HCTRL_LCTRL                    GENMASK(10, 8)

#define CDNS_PORTCTRL                           0x130
#define CDNS_PORTCTRL_TEST_FAILED               BIT(1)
#define CDNS_PORTCTRL_DIRN                      BIT(7)
#define CDNS_PORTCTRL_BANK_INVERT               BIT(8)
#define CDNS_PORTCTRL_BULK_ENABLE               BIT(16)

#define CDNS_PORT_OFFSET                        0x80

#define CDNS_PDI_CONFIG(n)                      (0x1100 + (n) * 16)

#define CDNS_PDI_CONFIG_SOFT_RESET              BIT(24)
#define CDNS_PDI_CONFIG_CHANNEL                 GENMASK(15, 8)
#define CDNS_PDI_CONFIG_PORT                    GENMASK(4, 0)

/* Driver defaults */
#define CDNS_TX_TIMEOUT                         500

#define CDNS_SCP_RX_FIFOLEVEL                   0x2

/*
 * register accessor helpers
 */
static inline u32 cdns_readl(struct sdw_cdns *cdns, int offset)
{
        return readl(cdns->registers + offset);
}

static inline void cdns_writel(struct sdw_cdns *cdns, int offset, u32 value)
{
        writel(value, cdns->registers + offset);
}

static inline u32 cdns_ip_readl(struct sdw_cdns *cdns, int offset)
{
        return cdns_readl(cdns, cdns->ip_offset + offset);
}

static inline void cdns_ip_writel(struct sdw_cdns *cdns, int offset, u32 value)
{
        return cdns_writel(cdns, cdns->ip_offset + offset, value);
}

static inline void cdns_updatel(struct sdw_cdns *cdns,
                                int offset, u32 mask, u32 val)
{
        u32 tmp;

        tmp = cdns_readl(cdns, offset);
        tmp = (tmp & ~mask) | val;
        cdns_writel(cdns, offset, tmp);
}

static inline void cdns_ip_updatel(struct sdw_cdns *cdns,
                                   int offset, u32 mask, u32 val)
{
        cdns_updatel(cdns, cdns->ip_offset + offset, mask, val);
}

static int cdns_set_wait(struct sdw_cdns *cdns, int offset, u32 mask, u32 value)
{
        int timeout = 10;
        u32 reg_read;

        /* Wait for bit to be set */
        do {
                reg_read = readl(cdns->registers + offset);
                if ((reg_read & mask) == value)
                        return 0;

                timeout--;
                usleep_range(50, 100);
        } while (timeout != 0);

        return -ETIMEDOUT;
}

static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value)
{
        writel(value, cdns->registers + offset);

        /* Wait for bit to be self cleared */
        return cdns_set_wait(cdns, offset, value, 0);
}

/*
 * all changes to the MCP_CONFIG, MCP_CONTROL, MCP_CMDCTRL and MCP_PHYCTRL
 * need to be confirmed with a write to MCP_CONFIG_UPDATE
 */
static int cdns_config_update(struct sdw_cdns *cdns)
{
        int ret;

        if (sdw_cdns_is_clock_stop(cdns)) {
                dev_err(cdns->dev, "Cannot program MCP_CONFIG_UPDATE in ClockStopMode\n");
                return -EINVAL;
        }

        ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE,
                             CDNS_MCP_CONFIG_UPDATE_BIT);
        if (ret < 0)
                dev_err(cdns->dev, "Config update timedout\n");

        return ret;
}

/**
 * sdw_cdns_config_update() - Update configurations
 * @cdns: Cadence instance
 */
void sdw_cdns_config_update(struct sdw_cdns *cdns)
{
        /* commit changes */
        cdns_writel(cdns, CDNS_MCP_CONFIG_UPDATE, CDNS_MCP_CONFIG_UPDATE_BIT);
}
EXPORT_SYMBOL(sdw_cdns_config_update);

/**
 * sdw_cdns_config_update_set_wait() - wait until configuration update bit is self-cleared
 * @cdns: Cadence instance
 */
int sdw_cdns_config_update_set_wait(struct sdw_cdns *cdns)
{
        /* the hardware recommendation is to wait at least 300us */
        return cdns_set_wait(cdns, CDNS_MCP_CONFIG_UPDATE,
                             CDNS_MCP_CONFIG_UPDATE_BIT, 0);
}
EXPORT_SYMBOL(sdw_cdns_config_update_set_wait);

/*
 * debugfs
 */
#ifdef CONFIG_DEBUG_FS

#define RD_BUF (2 * PAGE_SIZE)

static ssize_t cdns_sprintf(struct sdw_cdns *cdns,
                            char *buf, size_t pos, unsigned int reg)
{
        return scnprintf(buf + pos, RD_BUF - pos,
                         "%4x\t%8x\n", reg, cdns_readl(cdns, reg));
}

static int cdns_reg_show(struct seq_file *s, void *data)
{
        struct sdw_cdns *cdns = s->private;
        ssize_t ret;
        int num_ports;
        int i, j;

        char *buf __free(kfree) = kzalloc(RD_BUF, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        ret = scnprintf(buf, RD_BUF, "Register  Value\n");
        ret += scnprintf(buf + ret, RD_BUF - ret, "\nMCP Registers\n");
        /* 8 MCP registers */
        for (i = CDNS_MCP_CONFIG; i <= CDNS_MCP_PHYCTRL; i += sizeof(u32))
                ret += cdns_sprintf(cdns, buf, ret, i);

        ret += scnprintf(buf + ret, RD_BUF - ret,
                         "\nStatus & Intr Registers\n");
        /* 13 Status & Intr registers (offsets 0x70 and 0x74 not defined) */
        for (i = CDNS_MCP_STAT; i <=  CDNS_MCP_FIFOSTAT; i += sizeof(u32))
                ret += cdns_sprintf(cdns, buf, ret, i);

        ret += scnprintf(buf + ret, RD_BUF - ret,
                         "\nSSP & Clk ctrl Registers\n");
        ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_SSP_CTRL0);
        ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_SSP_CTRL1);
        ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_CLK_CTRL0);
        ret += cdns_sprintf(cdns, buf, ret, CDNS_MCP_CLK_CTRL1);

        ret += scnprintf(buf + ret, RD_BUF - ret,
                         "\nDPn B0 Registers\n");

        num_ports = cdns->num_ports;

        for (i = 0; i < num_ports; i++) {
                ret += scnprintf(buf + ret, RD_BUF - ret,
                                 "\nDP-%d\n", i);
                for (j = CDNS_DPN_B0_CONFIG(i);
                     j < CDNS_DPN_B0_ASYNC_CTRL(i); j += sizeof(u32))
                        ret += cdns_sprintf(cdns, buf, ret, j);
        }

        ret += scnprintf(buf + ret, RD_BUF - ret,
                         "\nDPn B1 Registers\n");
        for (i = 0; i < num_ports; i++) {
                ret += scnprintf(buf + ret, RD_BUF - ret,
                                 "\nDP-%d\n", i);

                for (j = CDNS_DPN_B1_CONFIG(i);
                     j < CDNS_DPN_B1_ASYNC_CTRL(i); j += sizeof(u32))
                        ret += cdns_sprintf(cdns, buf, ret, j);
        }

        ret += scnprintf(buf + ret, RD_BUF - ret,
                         "\nDPn Control Registers\n");
        for (i = 0; i < num_ports; i++)
                ret += cdns_sprintf(cdns, buf, ret,
                                CDNS_PORTCTRL + i * CDNS_PORT_OFFSET);

        ret += scnprintf(buf + ret, RD_BUF - ret,
                         "\nPDIn Config Registers\n");

        /* number of PDI and ports is interchangeable */
        for (i = 0; i < num_ports; i++)
                ret += cdns_sprintf(cdns, buf, ret, CDNS_PDI_CONFIG(i));

        seq_printf(s, "%s", buf);

        return 0;
}
DEFINE_SHOW_ATTRIBUTE(cdns_reg);

static int cdns_hw_reset(void *data, u64 value)
{
        struct sdw_cdns *cdns = data;
        int ret;

        if (value != 1)
                return -EINVAL;

        /* Userspace changed the hardware state behind the kernel's back */
        add_taint(TAINT_USER, LOCKDEP_STILL_OK);

        ret = sdw_cdns_exit_reset(cdns);

        dev_dbg(cdns->dev, "link hw_reset done: %d\n", ret);

        return ret;
}

DEFINE_DEBUGFS_ATTRIBUTE(cdns_hw_reset_fops, NULL, cdns_hw_reset, "%llu\n");

static int cdns_parity_error_injection(void *data, u64 value)
{
        struct sdw_cdns *cdns = data;
        struct sdw_bus *bus;
        int ret;

        if (value != 1)
                return -EINVAL;

        bus = &cdns->bus;

        /*
         * Resume Master device. If this results in a bus reset, the
         * Slave devices will re-attach and be re-enumerated.
         */
        ret = pm_runtime_resume_and_get(bus->dev);
        if (ret < 0 && ret != -EACCES) {
                dev_err_ratelimited(cdns->dev,
                                    "pm_runtime_resume_and_get failed in %s, ret %d\n",
                                    __func__, ret);
                return ret;
        }

        /*
         * wait long enough for Slave(s) to be in steady state. This
         * does not need to be super precise.
         */
        msleep(200);

        /*
         * Take the bus lock here to make sure that any bus transactions
         * will be queued while we inject a parity error on a dummy read
         */
        mutex_lock(&bus->bus_lock);

        /* program hardware to inject parity error */
        cdns_ip_updatel(cdns, CDNS_IP_MCP_CMDCTRL,
                        CDNS_IP_MCP_CMDCTRL_INSERT_PARITY_ERR,
                        CDNS_IP_MCP_CMDCTRL_INSERT_PARITY_ERR);

        /* commit changes */
        ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE, CDNS_MCP_CONFIG_UPDATE_BIT);
        if (ret < 0)
                goto unlock;

        /* do a broadcast dummy read to avoid bus clashes */
        ret = sdw_bread_no_pm_unlocked(&cdns->bus, 0xf, SDW_SCP_DEVID_0);
        dev_info(cdns->dev, "parity error injection, read: %d\n", ret);

        /* program hardware to disable parity error */
        cdns_ip_updatel(cdns, CDNS_IP_MCP_CMDCTRL,
                        CDNS_IP_MCP_CMDCTRL_INSERT_PARITY_ERR,
                        0);

        /* commit changes */
        ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE, CDNS_MCP_CONFIG_UPDATE_BIT);
        if (ret < 0)
                goto unlock;

        /* Userspace changed the hardware state behind the kernel's back */
        add_taint(TAINT_USER, LOCKDEP_STILL_OK);

unlock:
        /* Continue bus operation with parity error injection disabled */
        mutex_unlock(&bus->bus_lock);

        /*
         * allow Master device to enter pm_runtime suspend. This may
         * also result in Slave devices suspending.
         */
        pm_runtime_mark_last_busy(bus->dev);
        pm_runtime_put_autosuspend(bus->dev);

        return 0;
}

DEFINE_DEBUGFS_ATTRIBUTE(cdns_parity_error_fops, NULL,
                         cdns_parity_error_injection, "%llu\n");

static int cdns_set_pdi_loopback_source(void *data, u64 value)
{
        struct sdw_cdns *cdns = data;
        unsigned int pdi_out_num = cdns->pcm.num_bd + cdns->pcm.num_out;

        if (value > pdi_out_num)
                return -EINVAL;

        /* Userspace changed the hardware state behind the kernel's back */
        add_taint(TAINT_USER, LOCKDEP_STILL_OK);

        cdns->pdi_loopback_source = value;

        return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(cdns_pdi_loopback_source_fops, NULL, cdns_set_pdi_loopback_source, "%llu\n");

static int cdns_set_pdi_loopback_target(void *data, u64 value)
{
        struct sdw_cdns *cdns = data;
        unsigned int pdi_in_num = cdns->pcm.num_bd + cdns->pcm.num_in;

        if (value > pdi_in_num)
                return -EINVAL;

        /* Userspace changed the hardware state behind the kernel's back */
        add_taint(TAINT_USER, LOCKDEP_STILL_OK);

        cdns->pdi_loopback_target = value;

        return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(cdns_pdi_loopback_target_fops, NULL, cdns_set_pdi_loopback_target, "%llu\n");

/**
 * sdw_cdns_debugfs_init() - Cadence debugfs init
 * @cdns: Cadence instance
 * @root: debugfs root
 */
void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
{
        debugfs_create_file("cdns-registers", 0400, root, cdns, &cdns_reg_fops);

        debugfs_create_file("cdns-hw-reset", 0200, root, cdns,
                            &cdns_hw_reset_fops);

        debugfs_create_file("cdns-parity-error-injection", 0200, root, cdns,
                            &cdns_parity_error_fops);

        cdns->pdi_loopback_source = -1;
        cdns->pdi_loopback_target = -1;

        debugfs_create_file("cdns-pdi-loopback-source", 0200, root, cdns,
                            &cdns_pdi_loopback_source_fops);

        debugfs_create_file("cdns-pdi-loopback-target", 0200, root, cdns,
                            &cdns_pdi_loopback_target_fops);

}
EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);

#endif /* CONFIG_DEBUG_FS */

/*
 * IO Calls
 */
static enum sdw_command_response
cdns_fill_msg_resp(struct sdw_cdns *cdns,
                   struct sdw_msg *msg, int count, int offset)
{
        int nack = 0, no_ack = 0;
        int i;

        /* check message response */
        for (i = 0; i < count; i++) {
                if (!(cdns->response_buf[i] & CDNS_MCP_RESP_ACK)) {
                        no_ack = 1;
                        dev_vdbg(cdns->dev, "Msg Ack not received, cmd %d\n", i);
                }
                if (cdns->response_buf[i] & CDNS_MCP_RESP_NACK) {
                        nack = 1;
                        dev_err_ratelimited(cdns->dev, "Msg NACK received, cmd %d\n", i);
                }
        }

        if (nack) {
                dev_err_ratelimited(cdns->dev, "Msg NACKed for Slave %d\n", msg->dev_num);
                return SDW_CMD_FAIL;
        }

        if (no_ack) {
                dev_dbg_ratelimited(cdns->dev, "Msg ignored for Slave %d\n", msg->dev_num);
                return SDW_CMD_IGNORED;
        }

        if (msg->flags == SDW_MSG_FLAG_READ) {
                /* fill response */
                for (i = 0; i < count; i++)
                        msg->buf[i + offset] = FIELD_GET(CDNS_MCP_RESP_RDATA,
                                                         cdns->response_buf[i]);
        }

        return SDW_CMD_OK;
}

static void cdns_read_response(struct sdw_cdns *cdns)
{
        u32 num_resp, cmd_base;
        int i;

        /* RX_FIFO_AVAIL can be 2 entries more than the FIFO size */
        BUILD_BUG_ON(ARRAY_SIZE(cdns->response_buf) < CDNS_MCP_CMD_LEN + 2);

        num_resp = cdns_readl(cdns, CDNS_MCP_FIFOSTAT);
        num_resp &= CDNS_MCP_RX_FIFO_AVAIL;
        if (num_resp > ARRAY_SIZE(cdns->response_buf)) {
                dev_warn(cdns->dev, "RX AVAIL %d too long\n", num_resp);
                num_resp = ARRAY_SIZE(cdns->response_buf);
        }

        cmd_base = CDNS_IP_MCP_CMD_BASE;

        for (i = 0; i < num_resp; i++) {
                cdns->response_buf[i] = cdns_ip_readl(cdns, cmd_base);
                cmd_base += CDNS_MCP_CMD_WORD_LEN;
        }
}

static enum sdw_command_response
_cdns_xfer_msg(struct sdw_cdns *cdns, struct sdw_msg *msg, int cmd,
               int offset, int count, bool defer)
{
        unsigned long time;
        u32 base, i, data;
        u16 addr;

        /* Program the watermark level for RX FIFO */
        if (cdns->msg_count != count) {
                cdns_writel(cdns, CDNS_MCP_FIFOLEVEL, count);
                cdns->msg_count = count;
        }

        base = CDNS_IP_MCP_CMD_BASE;
        addr = msg->addr + offset;

        for (i = 0; i < count; i++) {
                data = FIELD_PREP(CDNS_MCP_CMD_DEV_ADDR, msg->dev_num);
                data |= FIELD_PREP(CDNS_MCP_CMD_COMMAND, cmd);
                data |= FIELD_PREP(CDNS_MCP_CMD_REG_ADDR, addr);
                addr++;

                if (msg->flags == SDW_MSG_FLAG_WRITE)
                        data |= msg->buf[i + offset];

                data |= FIELD_PREP(CDNS_MCP_CMD_SSP_TAG, msg->ssp_sync);
                cdns_ip_writel(cdns, base, data);
                base += CDNS_MCP_CMD_WORD_LEN;
        }

        if (defer)
                return SDW_CMD_OK;

        /* wait for timeout or response */
        time = wait_for_completion_timeout(&cdns->tx_complete,
                                           msecs_to_jiffies(CDNS_TX_TIMEOUT));
        if (!time) {
                dev_err(cdns->dev, "IO transfer timed out, cmd %d device %d addr %x len %d\n",
                        cmd, msg->dev_num, msg->addr, msg->len);
                msg->len = 0;

                /* Drain anything in the RX_FIFO */
                cdns_read_response(cdns);

                return SDW_CMD_TIMEOUT;
        }

        return cdns_fill_msg_resp(cdns, msg, count, offset);
}

static enum sdw_command_response
cdns_program_scp_addr(struct sdw_cdns *cdns, struct sdw_msg *msg)
{
        int nack = 0, no_ack = 0;
        unsigned long time;
        u32 data[2], base;
        int i;

        /* Program the watermark level for RX FIFO */
        if (cdns->msg_count != CDNS_SCP_RX_FIFOLEVEL) {
                cdns_writel(cdns, CDNS_MCP_FIFOLEVEL, CDNS_SCP_RX_FIFOLEVEL);
                cdns->msg_count = CDNS_SCP_RX_FIFOLEVEL;
        }

        data[0] = FIELD_PREP(CDNS_MCP_CMD_DEV_ADDR, msg->dev_num);
        data[0] |= FIELD_PREP(CDNS_MCP_CMD_COMMAND, 0x3);
        data[1] = data[0];

        data[0] |= FIELD_PREP(CDNS_MCP_CMD_REG_ADDR, SDW_SCP_ADDRPAGE1);
        data[1] |= FIELD_PREP(CDNS_MCP_CMD_REG_ADDR, SDW_SCP_ADDRPAGE2);

        data[0] |= msg->addr_page1;
        data[1] |= msg->addr_page2;

        base = CDNS_IP_MCP_CMD_BASE;
        cdns_ip_writel(cdns, base, data[0]);
        base += CDNS_MCP_CMD_WORD_LEN;
        cdns_ip_writel(cdns, base, data[1]);

        time = wait_for_completion_timeout(&cdns->tx_complete,
                                           msecs_to_jiffies(CDNS_TX_TIMEOUT));
        if (!time) {
                dev_err(cdns->dev, "SCP Msg trf timed out\n");
                msg->len = 0;
                return SDW_CMD_TIMEOUT;
        }

        /* check response the writes */
        for (i = 0; i < 2; i++) {
                if (!(cdns->response_buf[i] & CDNS_MCP_RESP_ACK)) {
                        no_ack = 1;
                        dev_err(cdns->dev, "Program SCP Ack not received\n");
                        if (cdns->response_buf[i] & CDNS_MCP_RESP_NACK) {
                                nack = 1;
                                dev_err(cdns->dev, "Program SCP NACK received\n");
                        }
                }
        }

        /* For NACK, NO ack, don't return err if we are in Broadcast mode */
        if (nack) {
                dev_err_ratelimited(cdns->dev,
                                    "SCP_addrpage NACKed for Slave %d\n", msg->dev_num);
                return SDW_CMD_FAIL;
        }

        if (no_ack) {
                dev_dbg_ratelimited(cdns->dev,
                                    "SCP_addrpage ignored for Slave %d\n", msg->dev_num);
                return SDW_CMD_IGNORED;
        }

        return SDW_CMD_OK;
}

static int cdns_prep_msg(struct sdw_cdns *cdns, struct sdw_msg *msg, int *cmd)
{
        int ret;

        if (msg->page) {
                ret = cdns_program_scp_addr(cdns, msg);
                if (ret) {
                        msg->len = 0;
                        return ret;
                }
        }

        switch (msg->flags) {
        case SDW_MSG_FLAG_READ:
                *cmd = CDNS_MCP_CMD_READ;
                break;

        case SDW_MSG_FLAG_WRITE:
                *cmd = CDNS_MCP_CMD_WRITE;
                break;

        default:
                dev_err(cdns->dev, "Invalid msg cmd: %d\n", msg->flags);
                return -EINVAL;
        }

        return 0;
}

enum sdw_command_response
cdns_xfer_msg(struct sdw_bus *bus, struct sdw_msg *msg)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        int cmd = 0, ret, i;

        ret = cdns_prep_msg(cdns, msg, &cmd);
        if (ret)
                return SDW_CMD_FAIL_OTHER;

        for (i = 0; i < msg->len / CDNS_MCP_CMD_LEN; i++) {
                ret = _cdns_xfer_msg(cdns, msg, cmd, i * CDNS_MCP_CMD_LEN,
                                     CDNS_MCP_CMD_LEN, false);
                if (ret != SDW_CMD_OK)
                        return ret;
        }

        if (!(msg->len % CDNS_MCP_CMD_LEN))
                return SDW_CMD_OK;

        return _cdns_xfer_msg(cdns, msg, cmd, i * CDNS_MCP_CMD_LEN,
                              msg->len % CDNS_MCP_CMD_LEN, false);
}
EXPORT_SYMBOL(cdns_xfer_msg);

enum sdw_command_response
cdns_xfer_msg_defer(struct sdw_bus *bus)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        struct sdw_defer *defer = &bus->defer_msg;
        struct sdw_msg *msg = defer->msg;
        int cmd = 0, ret;

        /* for defer only 1 message is supported */
        if (msg->len > 1)
                return -ENOTSUPP;

        ret = cdns_prep_msg(cdns, msg, &cmd);
        if (ret)
                return SDW_CMD_FAIL_OTHER;

        return _cdns_xfer_msg(cdns, msg, cmd, 0, msg->len, true);
}
EXPORT_SYMBOL(cdns_xfer_msg_defer);

u32 cdns_read_ping_status(struct sdw_bus *bus)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);

        return cdns_readl(cdns, CDNS_MCP_SLAVE_STAT);
}
EXPORT_SYMBOL(cdns_read_ping_status);

/*
 * IRQ handling
 */

static int cdns_update_slave_status(struct sdw_cdns *cdns,
                                    u64 slave_intstat)
{
        enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
        bool is_slave = false;
        u32 mask;
        u32 val;
        int i, set_status;

        memset(status, 0, sizeof(status));

        for (i = 0; i <= SDW_MAX_DEVICES; i++) {
                mask = (slave_intstat >> (i * CDNS_MCP_SLAVE_STATUS_NUM)) &
                        CDNS_MCP_SLAVE_STATUS_BITS;

                set_status = 0;

                if (mask) {
                        is_slave = true;

                        if (mask & CDNS_MCP_SLAVE_INTSTAT_RESERVED) {
                                status[i] = SDW_SLAVE_RESERVED;
                                set_status++;
                        }

                        if (mask & CDNS_MCP_SLAVE_INTSTAT_ATTACHED) {
                                status[i] = SDW_SLAVE_ATTACHED;
                                set_status++;
                        }

                        if (mask & CDNS_MCP_SLAVE_INTSTAT_ALERT) {
                                status[i] = SDW_SLAVE_ALERT;
                                set_status++;
                        }

                        if (mask & CDNS_MCP_SLAVE_INTSTAT_NPRESENT) {
                                status[i] = SDW_SLAVE_UNATTACHED;
                                set_status++;
                        }
                }

                /*
                 * check that there was a single reported Slave status and when
                 * there is not use the latest status extracted from PING commands
                 */
                if (set_status != 1) {
                        val = cdns_readl(cdns, CDNS_MCP_SLAVE_STAT);
                        val >>= (i * 2);

                        switch (val & 0x3) {
                        case 0:
                                status[i] = SDW_SLAVE_UNATTACHED;
                                break;
                        case 1:
                                status[i] = SDW_SLAVE_ATTACHED;
                                break;
                        case 2:
                                status[i] = SDW_SLAVE_ALERT;
                                break;
                        case 3:
                        default:
                                status[i] = SDW_SLAVE_RESERVED;
                                break;
                        }
                }
        }

        if (is_slave) {
                int ret;

                mutex_lock(&cdns->status_update_lock);
                ret = sdw_handle_slave_status(&cdns->bus, status);
                mutex_unlock(&cdns->status_update_lock);
                return ret;
        }

        return 0;
}

/**
 * sdw_cdns_irq() - Cadence interrupt handler
 * @irq: irq number
 * @dev_id: irq context
 */
irqreturn_t sdw_cdns_irq(int irq, void *dev_id)
{
        struct sdw_cdns *cdns = dev_id;
        u32 int_status;

        /* Check if the link is up */
        if (!cdns->link_up)
                return IRQ_NONE;

        int_status = cdns_readl(cdns, CDNS_MCP_INTSTAT);

        /* check for reserved values read as zero */
        if (int_status & CDNS_MCP_INT_RESERVED)
                return IRQ_NONE;

        if (!(int_status & CDNS_MCP_INT_IRQ))
                return IRQ_NONE;

        if (int_status & CDNS_MCP_INT_RX_WL) {
                struct sdw_bus *bus = &cdns->bus;
                struct sdw_defer *defer = &bus->defer_msg;

                cdns_read_response(cdns);

                if (defer && defer->msg) {
                        cdns_fill_msg_resp(cdns, defer->msg,
                                           defer->length, 0);
                        complete(&defer->complete);
                } else {
                        complete(&cdns->tx_complete);
                }
        }

        if (int_status & CDNS_MCP_INT_PARITY) {
                /* Parity error detected by Master */
                dev_err_ratelimited(cdns->dev, "Parity error\n");
        }

        if (int_status & CDNS_MCP_INT_CTRL_CLASH) {
                /* Slave is driving bit slot during control word */
                dev_err_ratelimited(cdns->dev, "Bus clash for control word\n");
        }

        if (int_status & CDNS_MCP_INT_DATA_CLASH) {
                /*
                 * Multiple slaves trying to drive bit slot, or issue with
                 * ownership of data bits or Slave gone bonkers
                 */
                dev_err_ratelimited(cdns->dev, "Bus clash for data word\n");
        }

        if (cdns->bus.params.m_data_mode != SDW_PORT_DATA_MODE_NORMAL &&
            int_status & CDNS_MCP_INT_DPINT) {
                u32 port_intstat;

                /* just log which ports report an error */
                port_intstat = cdns_readl(cdns, CDNS_MCP_PORT_INTSTAT);
                dev_err_ratelimited(cdns->dev, "DP interrupt: PortIntStat %8x\n",
                                    port_intstat);

                /* clear status w/ write1 */
                cdns_writel(cdns, CDNS_MCP_PORT_INTSTAT, port_intstat);
        }

        if (int_status & CDNS_MCP_INT_SLAVE_MASK) {
                /* Mask the Slave interrupt and wake thread */
                cdns_updatel(cdns, CDNS_MCP_INTMASK,
                             CDNS_MCP_INT_SLAVE_MASK, 0);

                int_status &= ~CDNS_MCP_INT_SLAVE_MASK;

                /*
                 * Deal with possible race condition between interrupt
                 * handling and disabling interrupts on suspend.
                 *
                 * If the master is in the process of disabling
                 * interrupts, don't schedule a workqueue
                 */
                if (cdns->interrupt_enabled)
                        schedule_work(&cdns->work);
        }

        cdns_writel(cdns, CDNS_MCP_INTSTAT, int_status);
        return IRQ_HANDLED;
}
EXPORT_SYMBOL(sdw_cdns_irq);

static void cdns_check_attached_status_dwork(struct work_struct *work)
{
        struct sdw_cdns *cdns =
                container_of(work, struct sdw_cdns, attach_dwork.work);
        enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
        u32 val;
        int ret;
        int i;

        val = cdns_readl(cdns, CDNS_MCP_SLAVE_STAT);

        for (i = 0; i <= SDW_MAX_DEVICES; i++) {
                status[i] = val & 0x3;
                if (status[i])
                        dev_dbg(cdns->dev, "Peripheral %d status: %d\n", i, status[i]);
                val >>= 2;
        }

        mutex_lock(&cdns->status_update_lock);
        ret = sdw_handle_slave_status(&cdns->bus, status);
        mutex_unlock(&cdns->status_update_lock);
        if (ret < 0)
                dev_err(cdns->dev, "%s: sdw_handle_slave_status failed: %d\n", __func__, ret);
}

/**
 * cdns_update_slave_status_work - update slave status in a work since we will need to handle
 * other interrupts eg. CDNS_MCP_INT_RX_WL during the update slave
 * process.
 * @work: cdns worker thread
 */
static void cdns_update_slave_status_work(struct work_struct *work)
{
        struct sdw_cdns *cdns =
                container_of(work, struct sdw_cdns, work);
        u32 slave0, slave1;
        u64 slave_intstat;
        u32 device0_status;
        int retry_count = 0;

        /*
         * Clear main interrupt first so we don't lose any assertions
         * that happen during this function.
         */
        cdns_writel(cdns, CDNS_MCP_INTSTAT, CDNS_MCP_INT_SLAVE_MASK);

        slave0 = cdns_readl(cdns, CDNS_MCP_SLAVE_INTSTAT0);
        slave1 = cdns_readl(cdns, CDNS_MCP_SLAVE_INTSTAT1);

        /*
         * Clear the bits before handling so we don't lose any
         * bits that re-assert.
         */
        cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT0, slave0);
        cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT1, slave1);

        /* combine the two status */
        slave_intstat = ((u64)slave1 << 32) | slave0;

        dev_dbg_ratelimited(cdns->dev, "Slave status change: 0x%llx\n", slave_intstat);

update_status:
        cdns_update_slave_status(cdns, slave_intstat);

        /*
         * When there is more than one peripheral per link, it's
         * possible that a deviceB becomes attached after we deal with
         * the attachment of deviceA. Since the hardware does a
         * logical AND, the attachment of the second device does not
         * change the status seen by the driver.
         *
         * In that case, clearing the registers above would result in
         * the deviceB never being detected - until a change of status
         * is observed on the bus.
         *
         * To avoid this race condition, re-check if any device0 needs
         * attention with PING commands. There is no need to check for
         * ALERTS since they are not allowed until a non-zero
         * device_number is assigned.
         *
         * Do not clear the INTSTAT0/1. While looping to enumerate devices on
         * #0 there could be status changes on other devices - these must
         * be kept in the INTSTAT so they can be handled when all #0 devices
         * have been handled.
         */

        device0_status = cdns_readl(cdns, CDNS_MCP_SLAVE_STAT);
        device0_status &= 3;

        if (device0_status == SDW_SLAVE_ATTACHED) {
                if (retry_count++ < SDW_MAX_DEVICES) {
                        dev_dbg_ratelimited(cdns->dev,
                                            "Device0 detected after clearing status, iteration %d\n",
                                            retry_count);
                        slave_intstat = CDNS_MCP_SLAVE_INTSTAT_ATTACHED;
                        goto update_status;
                } else {
                        dev_err_ratelimited(cdns->dev,
                                            "Device0 detected after %d iterations\n",
                                            retry_count);
                }
        }

        /* unmask Slave interrupt now */
        cdns_updatel(cdns, CDNS_MCP_INTMASK,
                     CDNS_MCP_INT_SLAVE_MASK, CDNS_MCP_INT_SLAVE_MASK);

}

/* paranoia check to make sure self-cleared bits are indeed cleared */
void sdw_cdns_check_self_clearing_bits(struct sdw_cdns *cdns, const char *string,
                                       bool initial_delay, int reset_iterations)
{
        u32 ip_mcp_control;
        u32 mcp_control;
        u32 mcp_config_update;
        int i;

        if (initial_delay)
                usleep_range(1000, 1500);

        ip_mcp_control = cdns_ip_readl(cdns, CDNS_IP_MCP_CONTROL);

        /* the following bits should be cleared immediately */
        if (ip_mcp_control & CDNS_IP_MCP_CONTROL_SW_RST)
                dev_err(cdns->dev, "%s failed: IP_MCP_CONTROL_SW_RST is not cleared\n", string);

        mcp_control = cdns_readl(cdns, CDNS_MCP_CONTROL);

        /* the following bits should be cleared immediately */
        if (mcp_control & CDNS_MCP_CONTROL_CMD_RST)
                dev_err(cdns->dev, "%s failed: MCP_CONTROL_CMD_RST is not cleared\n", string);
        if (mcp_control & CDNS_MCP_CONTROL_SOFT_RST)
                dev_err(cdns->dev, "%s failed: MCP_CONTROL_SOFT_RST is not cleared\n", string);
        if (mcp_control & CDNS_MCP_CONTROL_CLK_STOP_CLR)
                dev_err(cdns->dev, "%s failed: MCP_CONTROL_CLK_STOP_CLR is not cleared\n", string);

        mcp_config_update = cdns_readl(cdns, CDNS_MCP_CONFIG_UPDATE);
        if (mcp_config_update & CDNS_MCP_CONFIG_UPDATE_BIT)
                dev_err(cdns->dev, "%s failed: MCP_CONFIG_UPDATE_BIT is not cleared\n", string);

        i = 0;
        while (mcp_control & CDNS_MCP_CONTROL_HW_RST) {
                if (i == reset_iterations) {
                        dev_err(cdns->dev, "%s failed: MCP_CONTROL_HW_RST is not cleared\n", string);
                        break;
                }

                dev_dbg(cdns->dev, "%s: MCP_CONTROL_HW_RST is not cleared at iteration %d\n", string, i);
                i++;

                usleep_range(1000, 1500);
                mcp_control = cdns_readl(cdns, CDNS_MCP_CONTROL);
        }

}
EXPORT_SYMBOL(sdw_cdns_check_self_clearing_bits);

/*
 * init routines
 */

/**
 * sdw_cdns_exit_reset() - Program reset parameters and start bus operations
 * @cdns: Cadence instance
 */
int sdw_cdns_exit_reset(struct sdw_cdns *cdns)
{
        /* keep reset delay unchanged to 4096 cycles */

        /* use hardware generated reset */
        cdns_updatel(cdns, CDNS_MCP_CONTROL,
                     CDNS_MCP_CONTROL_HW_RST,
                     CDNS_MCP_CONTROL_HW_RST);

        /* commit changes */
        return cdns_config_update(cdns);
}
EXPORT_SYMBOL(sdw_cdns_exit_reset);

/**
 * cdns_enable_slave_interrupts() - Enable SDW slave interrupts
 * @cdns: Cadence instance
 * @state: boolean for true/false
 */
static void cdns_enable_slave_interrupts(struct sdw_cdns *cdns, bool state)
{
        u32 mask;

        mask = cdns_readl(cdns, CDNS_MCP_INTMASK);
        if (state)
                mask |= CDNS_MCP_INT_SLAVE_MASK;
        else
                mask &= ~CDNS_MCP_INT_SLAVE_MASK;

        cdns_writel(cdns, CDNS_MCP_INTMASK, mask);
}

/**
 * sdw_cdns_enable_interrupt() - Enable SDW interrupts
 * @cdns: Cadence instance
 * @state: True if we are trying to enable interrupt.
 */
int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns, bool state)
{
        u32 slave_intmask0 = 0;
        u32 slave_intmask1 = 0;
        u32 mask = 0;

        if (!state)
                goto update_masks;

        slave_intmask0 = CDNS_MCP_SLAVE_INTMASK0_MASK;
        slave_intmask1 = CDNS_MCP_SLAVE_INTMASK1_MASK;

        /* enable detection of all slave state changes */
        mask = CDNS_MCP_INT_SLAVE_MASK;

        /* enable detection of bus issues */
        mask |= CDNS_MCP_INT_CTRL_CLASH | CDNS_MCP_INT_DATA_CLASH |
                CDNS_MCP_INT_PARITY;

        /* port interrupt limited to test modes for now */
        if (cdns->bus.params.m_data_mode != SDW_PORT_DATA_MODE_NORMAL)
                mask |= CDNS_MCP_INT_DPINT;

        /* enable detection of RX fifo level */
        mask |= CDNS_MCP_INT_RX_WL;

        /*
         * CDNS_MCP_INT_IRQ needs to be set otherwise all previous
         * settings are irrelevant
         */
        mask |= CDNS_MCP_INT_IRQ;

        if (interrupt_mask) /* parameter override */
                mask = interrupt_mask;

update_masks:
        /* clear slave interrupt status before enabling interrupt */
        if (state) {
                u32 slave_state;

                slave_state = cdns_readl(cdns, CDNS_MCP_SLAVE_INTSTAT0);
                cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT0, slave_state);
                slave_state = cdns_readl(cdns, CDNS_MCP_SLAVE_INTSTAT1);
                cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT1, slave_state);
        }
        cdns->interrupt_enabled = state;

        /*
         * Complete any on-going status updates before updating masks,
         * and cancel queued status updates.
         *
         * There could be a race with a new interrupt thrown before
         * the 3 mask updates below are complete, so in the interrupt
         * we use the 'interrupt_enabled' status to prevent new work
         * from being queued.
         */
        if (!state)
                cancel_work_sync(&cdns->work);

        cdns_writel(cdns, CDNS_MCP_SLAVE_INTMASK0, slave_intmask0);
        cdns_writel(cdns, CDNS_MCP_SLAVE_INTMASK1, slave_intmask1);
        cdns_writel(cdns, CDNS_MCP_INTMASK, mask);

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_enable_interrupt);

static int cdns_allocate_pdi(struct sdw_cdns *cdns,
                             struct sdw_cdns_pdi **stream,
                             u32 num)
{
        struct sdw_cdns_pdi *pdi;
        int i;

        if (!num)
                return 0;

        pdi = devm_kcalloc(cdns->dev, num, sizeof(*pdi), GFP_KERNEL);
        if (!pdi)
                return -ENOMEM;

        for (i = 0; i < num; i++) {
                pdi[i].num = i;
        }

        *stream = pdi;
        return 0;
}

/**
 * sdw_cdns_pdi_init() - PDI initialization routine
 *
 * @cdns: Cadence instance
 * @config: Stream configurations
 */
int sdw_cdns_pdi_init(struct sdw_cdns *cdns,
                      struct sdw_cdns_stream_config config)
{
        struct sdw_cdns_streams *stream;
        int ret;

        cdns->pcm.num_bd = config.pcm_bd;
        cdns->pcm.num_in = config.pcm_in;
        cdns->pcm.num_out = config.pcm_out;

        /* Allocate PDIs for PCMs */
        stream = &cdns->pcm;

        /* we allocate PDI0 and PDI1 which are used for Bulk */
        ret = cdns_allocate_pdi(cdns, &stream->bd, stream->num_bd);
        if (ret)
                return ret;

        ret = cdns_allocate_pdi(cdns, &stream->in, stream->num_in);
        if (ret)
                return ret;

        ret = cdns_allocate_pdi(cdns, &stream->out, stream->num_out);
        if (ret)
                return ret;

        /* Update total number of PCM PDIs */
        stream->num_pdi = stream->num_bd + stream->num_in + stream->num_out;
        cdns->num_ports = stream->num_pdi;

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_pdi_init);

static u32 cdns_set_initial_frame_shape(int n_rows, int n_cols)
{
        u32 val;
        int c;
        int r;

        r = sdw_find_row_index(n_rows);
        c = sdw_find_col_index(n_cols);

        val = FIELD_PREP(CDNS_MCP_FRAME_SHAPE_ROW_MASK, r);
        val |= FIELD_PREP(CDNS_MCP_FRAME_SHAPE_COL_MASK, c);

        return val;
}

static int cdns_init_clock_ctrl(struct sdw_cdns *cdns)
{
        struct sdw_bus *bus = &cdns->bus;
        struct sdw_master_prop *prop = &bus->prop;
        u32 val;
        u32 ssp_interval;
        int divider;

        dev_dbg(cdns->dev, "mclk %d max %d row %d col %d\n",
                prop->mclk_freq,
                prop->max_clk_freq,
                prop->default_row,
                prop->default_col);

        if (!prop->default_frame_rate || !prop->default_row) {
                dev_err(cdns->dev, "Default frame_rate %d or row %d is invalid\n",
                        prop->default_frame_rate, prop->default_row);
                return -EINVAL;
        }

        /* Set clock divider */
        divider = (prop->mclk_freq * SDW_DOUBLE_RATE_FACTOR /
                bus->params.curr_dr_freq) - 1;

        cdns_updatel(cdns, CDNS_MCP_CLK_CTRL0,
                     CDNS_MCP_CLK_MCLKD_MASK, divider);
        cdns_updatel(cdns, CDNS_MCP_CLK_CTRL1,
                     CDNS_MCP_CLK_MCLKD_MASK, divider);

        /* Set frame shape base on the actual bus frequency. */
        prop->default_col = bus->params.curr_dr_freq /
                            prop->default_frame_rate / prop->default_row;

        /*
         * Frame shape changes after initialization have to be done
         * with the bank switch mechanism
         */
        val = cdns_set_initial_frame_shape(prop->default_row,
                                           prop->default_col);
        cdns_writel(cdns, CDNS_MCP_FRAME_SHAPE_INIT, val);

        /* Set SSP interval to default value */
        ssp_interval = prop->default_frame_rate / SDW_CADENCE_GSYNC_HZ;
        cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, ssp_interval);
        cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, ssp_interval);

        return 0;
}

/**
 * sdw_cdns_soft_reset() - Cadence soft-reset
 * @cdns: Cadence instance
 */
int sdw_cdns_soft_reset(struct sdw_cdns *cdns)
{
        int ret;

        cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_SOFT_RST,
                     CDNS_MCP_CONTROL_SOFT_RST);

        ret = cdns_config_update(cdns);
        if (ret < 0) {
                dev_err(cdns->dev, "%s: config update failed\n", __func__);
                return ret;
        }

        ret = cdns_set_wait(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_SOFT_RST, 0);
        if (ret < 0)
                dev_err(cdns->dev, "%s: Soft Reset timed out\n", __func__);

        return ret;
}
EXPORT_SYMBOL(sdw_cdns_soft_reset);

/**
 * sdw_cdns_init() - Cadence initialization
 * @cdns: Cadence instance
 */
int sdw_cdns_init(struct sdw_cdns *cdns)
{
        int ret;
        u32 val;

        ret = cdns_init_clock_ctrl(cdns);
        if (ret)
                return ret;

        sdw_cdns_check_self_clearing_bits(cdns, __func__, false, 0);

        /* reset msg_count to default value of FIFOLEVEL */
        cdns->msg_count = cdns_readl(cdns, CDNS_MCP_FIFOLEVEL);

        /* flush command FIFOs */
        cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_RST,
                     CDNS_MCP_CONTROL_CMD_RST);

        /* Set cmd accept mode */
        cdns_ip_updatel(cdns, CDNS_IP_MCP_CONTROL, CDNS_IP_MCP_CONTROL_CMD_ACCEPT,
                        CDNS_IP_MCP_CONTROL_CMD_ACCEPT);

        /* disable wakeup */
        cdns_ip_updatel(cdns, CDNS_IP_MCP_CONTROL,
                        CDNS_IP_MCP_CONTROL_BLOCK_WAKEUP,
                        0);

        /* Configure mcp config */
        val = cdns_readl(cdns, CDNS_MCP_CONFIG);

        /* Disable auto bus release */
        val &= ~CDNS_MCP_CONFIG_BUS_REL;

        cdns_writel(cdns, CDNS_MCP_CONFIG, val);

        /* Configure IP mcp config */
        val = cdns_ip_readl(cdns, CDNS_IP_MCP_CONFIG);

        /* enable bus operations with clock and data */
        val &= ~CDNS_IP_MCP_CONFIG_OP;
        val |= CDNS_IP_MCP_CONFIG_OP_NORMAL;

        /* Set cmd mode for Tx and Rx cmds */
        val &= ~CDNS_IP_MCP_CONFIG_CMD;

        /* Disable sniffer mode */
        val &= ~CDNS_IP_MCP_CONFIG_SNIFFER;

        if (cdns->bus.multi_link)
                /* Set Multi-master mode to take gsync into account */
                val |= CDNS_IP_MCP_CONFIG_MMASTER;

        /* leave frame delay to hardware default of 0x1F */

        /* leave command retry to hardware default of 0 */

        cdns_ip_writel(cdns, CDNS_IP_MCP_CONFIG, val);

        /* changes will be committed later */
        return 0;
}
EXPORT_SYMBOL(sdw_cdns_init);

int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params)
{
        struct sdw_master_prop *prop = &bus->prop;
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        int mcp_clkctrl_off;
        int divider;

        if (!params->curr_dr_freq) {
                dev_err(cdns->dev, "NULL curr_dr_freq\n");
                return -EINVAL;
        }

        divider = prop->mclk_freq * SDW_DOUBLE_RATE_FACTOR /
                params->curr_dr_freq;
        divider--; /* divider is 1/(N+1) */

        if (params->next_bank)
                mcp_clkctrl_off = CDNS_MCP_CLK_CTRL1;
        else
                mcp_clkctrl_off = CDNS_MCP_CLK_CTRL0;

        cdns_updatel(cdns, mcp_clkctrl_off, CDNS_MCP_CLK_MCLKD_MASK, divider);

        return 0;
}
EXPORT_SYMBOL(cdns_bus_conf);

static int cdns_port_params(struct sdw_bus *bus,
                            struct sdw_port_params *p_params, unsigned int bank)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        int dpn_config_off_source;
        int dpn_config_off_target;
        int target_num = p_params->num;
        int source_num = p_params->num;
        bool override = false;
        int dpn_config;

        if (target_num == cdns->pdi_loopback_target &&
            cdns->pdi_loopback_source != -1) {
                source_num = cdns->pdi_loopback_source;
                override = true;
        }

        if (bank) {
                dpn_config_off_source = CDNS_DPN_B1_CONFIG(source_num);
                dpn_config_off_target = CDNS_DPN_B1_CONFIG(target_num);
        } else {
                dpn_config_off_source = CDNS_DPN_B0_CONFIG(source_num);
                dpn_config_off_target = CDNS_DPN_B0_CONFIG(target_num);
        }

        dpn_config = cdns_readl(cdns, dpn_config_off_source);

        /* use port params if there is no loopback, otherwise use source as is */
        if (!override) {
                u32p_replace_bits(&dpn_config, p_params->bps - 1, CDNS_DPN_CONFIG_WL);
                u32p_replace_bits(&dpn_config, p_params->flow_mode, CDNS_DPN_CONFIG_PORT_FLOW);
                u32p_replace_bits(&dpn_config, p_params->data_mode, CDNS_DPN_CONFIG_PORT_DAT);
        }

        cdns_writel(cdns, dpn_config_off_target, dpn_config);

        return 0;
}

static int cdns_transport_params(struct sdw_bus *bus,
                                 struct sdw_transport_params *t_params,
                                 enum sdw_reg_bank bank)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        int dpn_config;
        int dpn_config_off_source;
        int dpn_config_off_target;
        int dpn_hctrl;
        int dpn_hctrl_off_source;
        int dpn_hctrl_off_target;
        int dpn_offsetctrl;
        int dpn_offsetctrl_off_source;
        int dpn_offsetctrl_off_target;
        int dpn_samplectrl;
        int dpn_samplectrl_off_source;
        int dpn_samplectrl_off_target;
        int source_num = t_params->port_num;
        int target_num = t_params->port_num;
        bool override = false;

        if (target_num == cdns->pdi_loopback_target &&
            cdns->pdi_loopback_source != -1) {
                source_num = cdns->pdi_loopback_source;
                override = true;
        }

        /*
         * Note: Only full data port is supported on the Master side for
         * both PCM and PDM ports.
         */

        if (bank) {
                dpn_config_off_source = CDNS_DPN_B1_CONFIG(source_num);
                dpn_hctrl_off_source = CDNS_DPN_B1_HCTRL(source_num);
                dpn_offsetctrl_off_source = CDNS_DPN_B1_OFFSET_CTRL(source_num);
                dpn_samplectrl_off_source = CDNS_DPN_B1_SAMPLE_CTRL(source_num);

                dpn_config_off_target = CDNS_DPN_B1_CONFIG(target_num);
                dpn_hctrl_off_target = CDNS_DPN_B1_HCTRL(target_num);
                dpn_offsetctrl_off_target = CDNS_DPN_B1_OFFSET_CTRL(target_num);
                dpn_samplectrl_off_target = CDNS_DPN_B1_SAMPLE_CTRL(target_num);

        } else {
                dpn_config_off_source = CDNS_DPN_B0_CONFIG(source_num);
                dpn_hctrl_off_source = CDNS_DPN_B0_HCTRL(source_num);
                dpn_offsetctrl_off_source = CDNS_DPN_B0_OFFSET_CTRL(source_num);
                dpn_samplectrl_off_source = CDNS_DPN_B0_SAMPLE_CTRL(source_num);

                dpn_config_off_target = CDNS_DPN_B0_CONFIG(target_num);
                dpn_hctrl_off_target = CDNS_DPN_B0_HCTRL(target_num);
                dpn_offsetctrl_off_target = CDNS_DPN_B0_OFFSET_CTRL(target_num);
                dpn_samplectrl_off_target = CDNS_DPN_B0_SAMPLE_CTRL(target_num);
        }

        dpn_config = cdns_readl(cdns, dpn_config_off_source);
        if (!override) {
                u32p_replace_bits(&dpn_config, t_params->blk_grp_ctrl, CDNS_DPN_CONFIG_BGC);
                u32p_replace_bits(&dpn_config, t_params->blk_pkg_mode, CDNS_DPN_CONFIG_BPM);
        }
        cdns_writel(cdns, dpn_config_off_target, dpn_config);

        if (!override) {
                dpn_offsetctrl = 0;
                u32p_replace_bits(&dpn_offsetctrl, t_params->offset1, CDNS_DPN_OFFSET_CTRL_1);
                u32p_replace_bits(&dpn_offsetctrl, t_params->offset2, CDNS_DPN_OFFSET_CTRL_2);
        } else {
                dpn_offsetctrl = cdns_readl(cdns, dpn_offsetctrl_off_source);
        }
        cdns_writel(cdns, dpn_offsetctrl_off_target,  dpn_offsetctrl);

        if (!override) {
                dpn_hctrl = 0;
                u32p_replace_bits(&dpn_hctrl, t_params->hstart, CDNS_DPN_HCTRL_HSTART);
                u32p_replace_bits(&dpn_hctrl, t_params->hstop, CDNS_DPN_HCTRL_HSTOP);
                u32p_replace_bits(&dpn_hctrl, t_params->lane_ctrl, CDNS_DPN_HCTRL_LCTRL);
        } else {
                dpn_hctrl = cdns_readl(cdns, dpn_hctrl_off_source);
        }
        cdns_writel(cdns, dpn_hctrl_off_target, dpn_hctrl);

        if (!override)
                dpn_samplectrl = t_params->sample_interval - 1;
        else
                dpn_samplectrl = cdns_readl(cdns, dpn_samplectrl_off_source);
        cdns_writel(cdns, dpn_samplectrl_off_target, dpn_samplectrl);

        return 0;
}

static int cdns_port_enable(struct sdw_bus *bus,
                            struct sdw_enable_ch *enable_ch, unsigned int bank)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        int dpn_chnen_off, ch_mask;

        if (bank)
                dpn_chnen_off = CDNS_DPN_B1_CH_EN(enable_ch->port_num);
        else
                dpn_chnen_off = CDNS_DPN_B0_CH_EN(enable_ch->port_num);

        ch_mask = enable_ch->ch_mask * enable_ch->enable;
        cdns_writel(cdns, dpn_chnen_off, ch_mask);

        return 0;
}

static const struct sdw_master_port_ops cdns_port_ops = {
        .dpn_set_port_params = cdns_port_params,
        .dpn_set_port_transport_params = cdns_transport_params,
        .dpn_port_enable_ch = cdns_port_enable,
};

/**
 * sdw_cdns_is_clock_stop: Check clock status
 *
 * @cdns: Cadence instance
 */
bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns)
{
        return !!(cdns_readl(cdns, CDNS_MCP_STAT) & CDNS_MCP_STAT_CLK_STOP);
}
EXPORT_SYMBOL(sdw_cdns_is_clock_stop);

/**
 * sdw_cdns_clock_stop: Cadence clock stop configuration routine
 *
 * @cdns: Cadence instance
 * @block_wake: prevent wakes if required by the platform
 */
int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake)
{
        bool slave_present = false;
        struct sdw_slave *slave;
        int ret;

        sdw_cdns_check_self_clearing_bits(cdns, __func__, false, 0);

        /* Check suspend status */
        if (sdw_cdns_is_clock_stop(cdns)) {
                dev_dbg(cdns->dev, "Clock is already stopped\n");
                return 0;
        }

        /*
         * Before entering clock stop we mask the Slave
         * interrupts. This helps avoid having to deal with e.g. a
         * Slave becoming UNATTACHED while the clock is being stopped
         */
        cdns_enable_slave_interrupts(cdns, false);

        /*
         * For specific platforms, it is required to be able to put
         * master into a state in which it ignores wake-up trials
         * in clock stop state
         */
        if (block_wake)
                cdns_ip_updatel(cdns, CDNS_IP_MCP_CONTROL,
                                CDNS_IP_MCP_CONTROL_BLOCK_WAKEUP,
                                CDNS_IP_MCP_CONTROL_BLOCK_WAKEUP);

        list_for_each_entry(slave, &cdns->bus.slaves, node) {
                if (slave->status == SDW_SLAVE_ATTACHED ||
                    slave->status == SDW_SLAVE_ALERT) {
                        slave_present = true;
                        break;
                }
        }

        /* commit changes */
        ret = cdns_config_update(cdns);
        if (ret < 0) {
                dev_err(cdns->dev, "%s: config_update failed\n", __func__);
                return ret;
        }

        /* Prepare slaves for clock stop */
        if (slave_present) {
                ret = sdw_bus_prep_clk_stop(&cdns->bus);
                if (ret < 0 && ret != -ENODATA) {
                        dev_err(cdns->dev, "prepare clock stop failed %d\n", ret);
                        return ret;
                }
        }

        /*
         * Enter clock stop mode and only report errors if there are
         * Slave devices present (ALERT or ATTACHED)
         */
        ret = sdw_bus_clk_stop(&cdns->bus);
        if (ret < 0 && slave_present && ret != -ENODATA) {
                dev_err(cdns->dev, "bus clock stop failed %d\n", ret);
                return ret;
        }

        ret = cdns_set_wait(cdns, CDNS_MCP_STAT,
                            CDNS_MCP_STAT_CLK_STOP,
                            CDNS_MCP_STAT_CLK_STOP);
        if (ret < 0)
                dev_err(cdns->dev, "Clock stop failed %d\n", ret);

        return ret;
}
EXPORT_SYMBOL(sdw_cdns_clock_stop);

/**
 * sdw_cdns_clock_restart: Cadence PM clock restart configuration routine
 *
 * @cdns: Cadence instance
 * @bus_reset: context may be lost while in low power modes and the bus
 * may require a Severe Reset and re-enumeration after a wake.
 */
int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset)
{
        int ret;

        /* unmask Slave interrupts that were masked when stopping the clock */
        cdns_enable_slave_interrupts(cdns, true);

        ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL,
                             CDNS_MCP_CONTROL_CLK_STOP_CLR);
        if (ret < 0) {
                dev_err(cdns->dev, "Couldn't exit from clock stop\n");
                return ret;
        }

        ret = cdns_set_wait(cdns, CDNS_MCP_STAT, CDNS_MCP_STAT_CLK_STOP, 0);
        if (ret < 0) {
                dev_err(cdns->dev, "clock stop exit failed %d\n", ret);
                return ret;
        }

        cdns_ip_updatel(cdns, CDNS_IP_MCP_CONTROL,
                        CDNS_IP_MCP_CONTROL_BLOCK_WAKEUP, 0);

        cdns_ip_updatel(cdns, CDNS_IP_MCP_CONTROL, CDNS_IP_MCP_CONTROL_CMD_ACCEPT,
                        CDNS_IP_MCP_CONTROL_CMD_ACCEPT);

        if (!bus_reset) {

                /* enable bus operations with clock and data */
                cdns_ip_updatel(cdns, CDNS_IP_MCP_CONFIG,
                                CDNS_IP_MCP_CONFIG_OP,
                                CDNS_IP_MCP_CONFIG_OP_NORMAL);

                ret = cdns_config_update(cdns);
                if (ret < 0) {
                        dev_err(cdns->dev, "%s: config_update failed\n", __func__);
                        return ret;
                }

                ret = sdw_bus_exit_clk_stop(&cdns->bus);
                if (ret < 0)
                        dev_err(cdns->dev, "bus failed to exit clock stop %d\n", ret);
        }

        return ret;
}
EXPORT_SYMBOL(sdw_cdns_clock_restart);

/**
 * sdw_cdns_probe() - Cadence probe routine
 * @cdns: Cadence instance
 */
int sdw_cdns_probe(struct sdw_cdns *cdns)
{
        init_completion(&cdns->tx_complete);
        cdns->bus.port_ops = &cdns_port_ops;

        mutex_init(&cdns->status_update_lock);

        INIT_WORK(&cdns->work, cdns_update_slave_status_work);
        INIT_DELAYED_WORK(&cdns->attach_dwork, cdns_check_attached_status_dwork);

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_probe);

int cdns_set_sdw_stream(struct snd_soc_dai *dai,
                        void *stream, int direction)
{
        struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai);
        struct sdw_cdns_dai_runtime *dai_runtime;

        dai_runtime = cdns->dai_runtime_array[dai->id];

        if (stream) {
                /* first paranoia check */
                if (dai_runtime) {
                        dev_err(dai->dev,
                                "dai_runtime already allocated for dai %s\n",
                                dai->name);
                        return -EINVAL;
                }

                /* allocate and set dai_runtime info */
                dai_runtime = kzalloc_obj(*dai_runtime);
                if (!dai_runtime)
                        return -ENOMEM;

                dai_runtime->stream_type = SDW_STREAM_PCM;

                dai_runtime->bus = &cdns->bus;
                dai_runtime->link_id = cdns->instance;

                dai_runtime->stream = stream;
                dai_runtime->direction = direction;

                cdns->dai_runtime_array[dai->id] = dai_runtime;
        } else {
                /* second paranoia check */
                if (!dai_runtime) {
                        dev_err(dai->dev,
                                "dai_runtime not allocated for dai %s\n",
                                dai->name);
                        return -EINVAL;
                }

                /* for NULL stream we release allocated dai_runtime */
                kfree(dai_runtime);
                cdns->dai_runtime_array[dai->id] = NULL;
        }
        return 0;
}
EXPORT_SYMBOL(cdns_set_sdw_stream);

/**
 * cdns_find_pdi() - Find a free PDI
 *
 * @cdns: Cadence instance
 * @num: Number of PDIs
 * @pdi: PDI instances
 * @dai_id: DAI id
 *
 * Find a PDI for a given PDI array. The PDI num and dai_id are
 * expected to match, return NULL otherwise.
 */
static struct sdw_cdns_pdi *cdns_find_pdi(struct sdw_cdns *cdns,
                                          unsigned int num,
                                          struct sdw_cdns_pdi *pdi,
                                          int dai_id)
{
        int i;

        for (i = 0; i < num; i++)
                if (pdi[i].num == dai_id)
                        return &pdi[i];

        return NULL;
}

/**
 * sdw_cdns_config_stream: Configure a stream
 *
 * @cdns: Cadence instance
 * @ch: Channel count
 * @dir: Data direction
 * @pdi: PDI to be used
 */
void sdw_cdns_config_stream(struct sdw_cdns *cdns,
                            u32 ch, u32 dir, struct sdw_cdns_pdi *pdi)
{
        u32 offset, val = 0;

        if (dir == SDW_DATA_DIR_RX) {
                val = CDNS_PORTCTRL_DIRN;

                if (cdns->bus.params.m_data_mode != SDW_PORT_DATA_MODE_NORMAL)
                        val |= CDNS_PORTCTRL_TEST_FAILED;
        } else if (pdi->num == 0 || pdi->num == 1) {
                val |= CDNS_PORTCTRL_BULK_ENABLE;
        }
        offset = CDNS_PORTCTRL + pdi->num * CDNS_PORT_OFFSET;
        cdns_updatel(cdns, offset,
                     CDNS_PORTCTRL_DIRN | CDNS_PORTCTRL_TEST_FAILED |
                     CDNS_PORTCTRL_BULK_ENABLE,
                     val);

        /* The DataPort0 needs to be mapped to both PDI0 and PDI1 ! */
        if (pdi->num == 1)
                val = 0;
        else
                val = pdi->num;
        val |= CDNS_PDI_CONFIG_SOFT_RESET;
        val |= FIELD_PREP(CDNS_PDI_CONFIG_CHANNEL, (1 << ch) - 1);
        cdns_writel(cdns, CDNS_PDI_CONFIG(pdi->num), val);
}
EXPORT_SYMBOL(sdw_cdns_config_stream);

/**
 * sdw_cdns_alloc_pdi() - Allocate a PDI
 *
 * @cdns: Cadence instance
 * @stream: Stream to be allocated
 * @ch: Channel count
 * @dir: Data direction
 * @dai_id: DAI id
 */
struct sdw_cdns_pdi *sdw_cdns_alloc_pdi(struct sdw_cdns *cdns,
                                        struct sdw_cdns_streams *stream,
                                        u32 ch, u32 dir, int dai_id)
{
        struct sdw_cdns_pdi *pdi = NULL;

        if (dir == SDW_DATA_DIR_RX)
                pdi = cdns_find_pdi(cdns, stream->num_in, stream->in,
                                    dai_id);
        else
                pdi = cdns_find_pdi(cdns, stream->num_out, stream->out,
                                    dai_id);

        /* check if we found a PDI, else find in bi-directional */
        if (!pdi)
                pdi = cdns_find_pdi(cdns, stream->num_bd, stream->bd,
                                    dai_id);

        if (pdi) {
                pdi->l_ch_num = 0;
                pdi->h_ch_num = ch - 1;
                pdi->dir = dir;
                pdi->ch_count = ch;
        }

        return pdi;
}
EXPORT_SYMBOL(sdw_cdns_alloc_pdi);

/*
 * the MIPI SoundWire CRC8 polynomial is X^8 + X^6 + X^3 + X^2 + 1, MSB first
 * The value is (1)01001101 = 0x4D
 *
 * the table below was generated with
 *
 *      u8 crc8_lookup_table[CRC8_TABLE_SIZE];
 *      crc8_populate_msb(crc8_lookup_table, SDW_CRC8_POLY);
 *
 */
#define SDW_CRC8_SEED 0xFF
#define SDW_CRC8_POLY 0x4D

static const u8 sdw_crc8_lookup_msb[CRC8_TABLE_SIZE] = {
        0x00, 0x4d, 0x9a, 0xd7, 0x79, 0x34, 0xe3, 0xae, /* 0 - 7 */
        0xf2, 0xbf, 0x68, 0x25, 0x8b, 0xc6, 0x11, 0x5c, /* 8 -15 */
        0xa9, 0xe4, 0x33, 0x7e, 0xd0, 0x9d, 0x4a, 0x07, /* 16 - 23 */
        0x5b, 0x16, 0xc1, 0x8c, 0x22, 0x6f, 0xb8, 0xf5, /* 24 - 31 */
        0x1f, 0x52, 0x85, 0xc8, 0x66, 0x2b, 0xfc, 0xb1, /* 32 - 39 */
        0xed, 0xa0, 0x77, 0x3a, 0x94, 0xd9, 0x0e, 0x43, /* 40 - 47 */
        0xb6, 0xfb, 0x2c, 0x61, 0xcf, 0x82, 0x55, 0x18, /* 48 - 55 */
        0x44, 0x09, 0xde, 0x93, 0x3d, 0x70, 0xa7, 0xea, /* 56 - 63 */
        0x3e, 0x73, 0xa4, 0xe9, 0x47, 0x0a, 0xdd, 0x90, /* 64 - 71 */
        0xcc, 0x81, 0x56, 0x1b, 0xb5, 0xf8, 0x2f, 0x62, /* 72 - 79 */
        0x97, 0xda, 0x0d, 0x40, 0xee, 0xa3, 0x74, 0x39, /* 80 - 87 */
        0x65, 0x28, 0xff, 0xb2, 0x1c, 0x51, 0x86, 0xcb, /* 88 - 95 */
        0x21, 0x6c, 0xbb, 0xf6, 0x58, 0x15, 0xc2, 0x8f, /* 96 - 103 */
        0xd3, 0x9e, 0x49, 0x04, 0xaa, 0xe7, 0x30, 0x7d, /* 104 - 111 */
        0x88, 0xc5, 0x12, 0x5f, 0xf1, 0xbc, 0x6b, 0x26, /* 112 - 119 */
        0x7a, 0x37, 0xe0, 0xad, 0x03, 0x4e, 0x99, 0xd4, /* 120 - 127 */
        0x7c, 0x31, 0xe6, 0xab, 0x05, 0x48, 0x9f, 0xd2, /* 128 - 135 */
        0x8e, 0xc3, 0x14, 0x59, 0xf7, 0xba, 0x6d, 0x20, /* 136 - 143 */
        0xd5, 0x98, 0x4f, 0x02, 0xac, 0xe1, 0x36, 0x7b, /* 144 - 151 */
        0x27, 0x6a, 0xbd, 0xf0, 0x5e, 0x13, 0xc4, 0x89, /* 152 - 159 */
        0x63, 0x2e, 0xf9, 0xb4, 0x1a, 0x57, 0x80, 0xcd, /* 160 - 167 */
        0x91, 0xdc, 0x0b, 0x46, 0xe8, 0xa5, 0x72, 0x3f, /* 168 - 175 */
        0xca, 0x87, 0x50, 0x1d, 0xb3, 0xfe, 0x29, 0x64, /* 176 - 183 */
        0x38, 0x75, 0xa2, 0xef, 0x41, 0x0c, 0xdb, 0x96, /* 184 - 191 */
        0x42, 0x0f, 0xd8, 0x95, 0x3b, 0x76, 0xa1, 0xec, /* 192 - 199 */
        0xb0, 0xfd, 0x2a, 0x67, 0xc9, 0x84, 0x53, 0x1e, /* 200 - 207 */
        0xeb, 0xa6, 0x71, 0x3c, 0x92, 0xdf, 0x08, 0x45, /* 208 - 215 */
        0x19, 0x54, 0x83, 0xce, 0x60, 0x2d, 0xfa, 0xb7, /* 216 - 223 */
        0x5d, 0x10, 0xc7, 0x8a, 0x24, 0x69, 0xbe, 0xf3, /* 224 - 231 */
        0xaf, 0xe2, 0x35, 0x78, 0xd6, 0x9b, 0x4c, 0x01, /* 232 - 239 */
        0xf4, 0xb9, 0x6e, 0x23, 0x8d, 0xc0, 0x17, 0x5a, /* 240 - 247 */
        0x06, 0x4b, 0x9c, 0xd1, 0x7f, 0x32, 0xe5, 0xa8  /* 248 - 255 */
};

/* BPT/BRA helpers */

#define SDW_CDNS_BRA_HDR                        6 /* defined by MIPI */
#define SDW_CDNS_BRA_HDR_CRC                    1 /* defined by MIPI */
#define SDW_CDNS_BRA_HDR_CRC_PAD                1 /* Cadence only */
#define SDW_CDNS_BRA_HDR_RESP                   1 /* defined by MIPI */
#define SDW_CDNS_BRA_HDR_RESP_PAD               1 /* Cadence only */

#define SDW_CDNS_BRA_DATA_PAD                   1 /* Cadence only */
#define SDW_CDNS_BRA_DATA_CRC                   1 /* defined by MIPI */
#define SDW_CDNS_BRA_DATA_CRC_PAD               1 /* Cadence only */

#define SDW_CDNS_BRA_FOOTER_RESP                1 /* defined by MIPI */
#define SDW_CDNS_BRA_FOOTER_RESP_PAD            1 /* Cadence only */

#define SDW_CDNS_WRITE_PDI1_BUFFER_SIZE                                                 \
        ((SDW_CDNS_BRA_HDR_RESP + SDW_CDNS_BRA_HDR_RESP_PAD +                           \
         SDW_CDNS_BRA_FOOTER_RESP + SDW_CDNS_BRA_FOOTER_RESP_PAD) * 2)

#define SDW_CDNS_READ_PDI0_BUFFER_SIZE                                                  \
        ((SDW_CDNS_BRA_HDR + SDW_CDNS_BRA_HDR_CRC + SDW_CDNS_BRA_HDR_CRC_PAD) * 2)

static unsigned int sdw_cdns_bra_actual_data_size(unsigned int allocated_bytes_per_frame)
{
        unsigned int total;

        if (allocated_bytes_per_frame < (SDW_CDNS_BRA_HDR + SDW_CDNS_BRA_HDR_CRC +
                                         SDW_CDNS_BRA_HDR_RESP + SDW_CDNS_BRA_DATA_CRC +
                                         SDW_CDNS_BRA_FOOTER_RESP))
                return 0;

        total = allocated_bytes_per_frame - SDW_CDNS_BRA_HDR - SDW_CDNS_BRA_HDR_CRC -
                SDW_CDNS_BRA_HDR_RESP - SDW_CDNS_BRA_DATA_CRC - SDW_CDNS_BRA_FOOTER_RESP;

        return total;
}

static unsigned int sdw_cdns_write_pdi0_buffer_size(unsigned int actual_data_size)
{
        unsigned int total;

        total = SDW_CDNS_BRA_HDR + SDW_CDNS_BRA_HDR_CRC + SDW_CDNS_BRA_HDR_CRC_PAD;

        total += actual_data_size;
        if (actual_data_size & 1)
                total += SDW_CDNS_BRA_DATA_PAD;

        total += SDW_CDNS_BRA_DATA_CRC + SDW_CDNS_BRA_DATA_CRC_PAD;

        return total * 2;
}

static unsigned int sdw_cdns_read_pdi1_buffer_size(unsigned int actual_data_size)
{
        unsigned int total;

        total = SDW_CDNS_BRA_HDR_RESP + SDW_CDNS_BRA_HDR_RESP_PAD;

        total += actual_data_size;
        if (actual_data_size & 1)
                total += SDW_CDNS_BRA_DATA_PAD;

        total += SDW_CDNS_BRA_HDR_CRC + SDW_CDNS_BRA_HDR_CRC_PAD;

        total += SDW_CDNS_BRA_FOOTER_RESP + SDW_CDNS_BRA_FOOTER_RESP_PAD;

        return total * 2;
}

int sdw_cdns_bpt_find_bandwidth(int command, /* 0: write, 1: read */
                                int row, int col, int frame_rate,
                                unsigned int *tx_dma_bandwidth,
                                unsigned int *rx_dma_bandwidth)
{
        unsigned int bpt_bits = row * (col - 1);
        unsigned int bpt_bytes = bpt_bits >> 3;
        unsigned int pdi0_buffer_size;
        unsigned int pdi1_buffer_size;
        unsigned int data_per_frame;

        data_per_frame = sdw_cdns_bra_actual_data_size(bpt_bytes);
        if (!data_per_frame)
                return -EINVAL;

        if (command == 0) {
                pdi0_buffer_size = sdw_cdns_write_pdi0_buffer_size(data_per_frame);
                pdi1_buffer_size = SDW_CDNS_WRITE_PDI1_BUFFER_SIZE;
        } else {
                pdi0_buffer_size = SDW_CDNS_READ_PDI0_BUFFER_SIZE;
                pdi1_buffer_size = sdw_cdns_read_pdi1_buffer_size(data_per_frame);
        }

        *tx_dma_bandwidth = pdi0_buffer_size * 8 * frame_rate;
        *rx_dma_bandwidth = pdi1_buffer_size * 8 * frame_rate;

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_bpt_find_bandwidth);

int sdw_cdns_bpt_find_buffer_sizes(int command, /* 0: write, 1: read */
                                   int row, int col, unsigned int data_bytes,
                                   unsigned int requested_bytes_per_frame,
                                   unsigned int *data_per_frame, unsigned int *pdi0_buffer_size,
                                   unsigned int *pdi1_buffer_size, unsigned int *num_frames)
{
        unsigned int bpt_bits = row * (col - 1);
        unsigned int bpt_bytes = bpt_bits >> 3;
        unsigned int actual_bpt_bytes;
        unsigned int pdi0_tx_size;
        unsigned int pdi1_rx_size;
        unsigned int remainder;

        if (!data_bytes)
                return -EINVAL;

        actual_bpt_bytes = sdw_cdns_bra_actual_data_size(bpt_bytes);
        if (!actual_bpt_bytes)
                return -EINVAL;

        /*
         * the caller may want to set the number of bytes per frame,
         * allow when possible
         */
        if (requested_bytes_per_frame < actual_bpt_bytes)
                actual_bpt_bytes = requested_bytes_per_frame;

        *data_per_frame = actual_bpt_bytes;

        if (data_bytes < actual_bpt_bytes)
                actual_bpt_bytes = data_bytes;

        if (command == 0) {
                /*
                 * for writes we need to send all the data_bytes per frame,
                 * even for the last frame which may only transport fewer bytes
                 */

                *num_frames = DIV_ROUND_UP(data_bytes, actual_bpt_bytes);

                pdi0_tx_size = sdw_cdns_write_pdi0_buffer_size(actual_bpt_bytes);
                pdi1_rx_size = SDW_CDNS_WRITE_PDI1_BUFFER_SIZE;

                *pdi0_buffer_size = pdi0_tx_size * *num_frames;
                *pdi1_buffer_size = pdi1_rx_size * *num_frames;
        } else {
                /*
                 * for reads we need to retrieve only what is requested in the BPT
                 * header, so the last frame needs to be special-cased
                 */
                *num_frames = data_bytes / actual_bpt_bytes;

                pdi0_tx_size = SDW_CDNS_READ_PDI0_BUFFER_SIZE;
                pdi1_rx_size = sdw_cdns_read_pdi1_buffer_size(actual_bpt_bytes);

                *pdi0_buffer_size = pdi0_tx_size * *num_frames;
                *pdi1_buffer_size = pdi1_rx_size * *num_frames;

                remainder = data_bytes % actual_bpt_bytes;
                if (remainder) {
                        pdi0_tx_size = SDW_CDNS_READ_PDI0_BUFFER_SIZE;
                        pdi1_rx_size = sdw_cdns_read_pdi1_buffer_size(remainder);

                        *num_frames = *num_frames + 1;
                        *pdi0_buffer_size += pdi0_tx_size;
                        *pdi1_buffer_size += pdi1_rx_size;
                }
        }

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_bpt_find_buffer_sizes);

static int sdw_cdns_copy_write_data(u8 *data, int data_size, u8 *dma_buffer, int dma_buffer_size)
{
        /*
         * the implementation copies the data one byte at a time. Experiments with
         * two bytes at a time did not seem to improve the performance
         */
        int i, j;

        /* size check to prevent out of bounds access */
        i = data_size - 1;
        j = (2 * i) - (i & 1);
        if (data_size & 1)
                j++;
        j += 2;
        if (j >= dma_buffer_size)
                return -EINVAL;

        /* copy data */
        for (i = 0; i < data_size; i++) {
                j = (2 * i) - (i & 1);
                dma_buffer[j] = data[i];
        }
        /* add required pad */
        if (data_size & 1)
                dma_buffer[++j] = 0;
        /* skip last two bytes */
        j += 2;

        /* offset and data are off-by-one */
        return j + 1;
}

static int sdw_cdns_prepare_write_pd0_buffer(u8 *header, unsigned int header_size,
                                             u8 *data, unsigned int data_size,
                                             u8 *dma_buffer, unsigned int dma_buffer_size,
                                             unsigned int *dma_data_written,
                                             unsigned int frame_counter)
{
        int data_written;
        u8 *last_byte;
        u8 crc;

        *dma_data_written = 0;

        data_written = sdw_cdns_copy_write_data(header, header_size, dma_buffer, dma_buffer_size);
        if (data_written < 0)
                return data_written;
        dma_buffer[3] = BIT(7);
        dma_buffer[3] |= frame_counter & GENMASK(3, 0);

        dma_buffer += data_written;
        dma_buffer_size -= data_written;
        *dma_data_written += data_written;

        crc = SDW_CRC8_SEED;
        crc = crc8(sdw_crc8_lookup_msb, header, header_size, crc);

        data_written = sdw_cdns_copy_write_data(&crc, 1, dma_buffer, dma_buffer_size);
        if (data_written < 0)
                return data_written;
        dma_buffer += data_written;
        dma_buffer_size -= data_written;
        *dma_data_written += data_written;

        data_written = sdw_cdns_copy_write_data(data, data_size, dma_buffer, dma_buffer_size);
        if (data_written < 0)
                return data_written;
        dma_buffer += data_written;
        dma_buffer_size -= data_written;
        *dma_data_written += data_written;

        crc = SDW_CRC8_SEED;
        crc = crc8(sdw_crc8_lookup_msb, data, data_size, crc);
        data_written = sdw_cdns_copy_write_data(&crc, 1, dma_buffer, dma_buffer_size);
        if (data_written < 0)
                return data_written;
        dma_buffer += data_written;
        dma_buffer_size -= data_written;
        *dma_data_written += data_written;

        /* tag last byte */
        last_byte = dma_buffer - 1;
        last_byte[0] = BIT(6);

        return 0;
}

static int sdw_cdns_prepare_read_pd0_buffer(u8 *header, unsigned int header_size,
                                            u8 *dma_buffer, unsigned int dma_buffer_size,
                                            unsigned int *dma_data_written,
                                            unsigned int frame_counter)
{
        int data_written;
        u8 *last_byte;
        u8 crc;

        *dma_data_written = 0;

        data_written = sdw_cdns_copy_write_data(header, header_size, dma_buffer, dma_buffer_size);
        if (data_written < 0)
                return data_written;
        dma_buffer[3] = BIT(7);
        dma_buffer[3] |= frame_counter & GENMASK(3, 0);

        dma_buffer += data_written;
        dma_buffer_size -= data_written;
        *dma_data_written += data_written;

        crc = SDW_CRC8_SEED;
        crc = crc8(sdw_crc8_lookup_msb, header, header_size, crc);

        data_written = sdw_cdns_copy_write_data(&crc, 1, dma_buffer, dma_buffer_size);
        if (data_written < 0)
                return data_written;
        dma_buffer += data_written;
        dma_buffer_size -= data_written;
        *dma_data_written += data_written;

        /* tag last byte */
        last_byte = dma_buffer - 1;
        last_byte[0] = BIT(6);

        return 0;
}

#define CDNS_BPT_ROLLING_COUNTER_START 1

int sdw_cdns_prepare_write_dma_buffer(u8 dev_num, struct sdw_bpt_section *sec, int num_sec,
                                      int data_per_frame, u8 *dma_buffer,
                                      int dma_buffer_size, int *dma_buffer_total_bytes)
{
        int total_dma_data_written = 0;
        u8 *p_dma_buffer = dma_buffer;
        u8 header[SDW_CDNS_BRA_HDR];
        unsigned int start_register;
        unsigned int section_size;
        int dma_data_written;
        u8 *p_data;
        u8 counter;
        int ret;
        int i;

        counter = CDNS_BPT_ROLLING_COUNTER_START;

        header[0] = BIT(1);             /* write command: BIT(1) set */
        header[0] |= GENMASK(7, 6);     /* header is active */
        header[0] |= (dev_num << 2);

        for (i = 0; i < num_sec; i++) {
                start_register = sec[i].addr;
                section_size = sec[i].len;
                p_data = sec[i].buf;

                while (section_size >= data_per_frame) {
                        header[1] = data_per_frame;
                        header[2] = start_register >> 24 & 0xFF;
                        header[3] = start_register >> 16 & 0xFF;
                        header[4] = start_register >> 8 & 0xFF;
                        header[5] = start_register >> 0 & 0xFF;

                        ret = sdw_cdns_prepare_write_pd0_buffer(header, SDW_CDNS_BRA_HDR,
                                                                p_data, data_per_frame,
                                                                p_dma_buffer, dma_buffer_size,
                                                                &dma_data_written, counter);
                        if (ret < 0)
                                return ret;

                        counter++;

                        p_data += data_per_frame;
                        section_size -= data_per_frame;

                        p_dma_buffer += dma_data_written;
                        dma_buffer_size -= dma_data_written;
                        total_dma_data_written += dma_data_written;

                        start_register += data_per_frame;
                }

                if (section_size) {
                        header[1] = section_size;
                        header[2] = start_register >> 24 & 0xFF;
                        header[3] = start_register >> 16 & 0xFF;
                        header[4] = start_register >> 8 & 0xFF;
                        header[5] = start_register >> 0 & 0xFF;

                        ret = sdw_cdns_prepare_write_pd0_buffer(header, SDW_CDNS_BRA_HDR,
                                                                p_data, section_size,
                                                                p_dma_buffer, dma_buffer_size,
                                                                &dma_data_written, counter);
                        if (ret < 0)
                                return ret;

                        counter++;

                        p_dma_buffer += dma_data_written;
                        dma_buffer_size -= dma_data_written;
                        total_dma_data_written += dma_data_written;
                }
        }

        *dma_buffer_total_bytes = total_dma_data_written;

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_prepare_write_dma_buffer);

int sdw_cdns_prepare_read_dma_buffer(u8 dev_num, struct sdw_bpt_section *sec, int num_sec,
                                     int data_per_frame, u8 *dma_buffer, int dma_buffer_size,
                                     int *dma_buffer_total_bytes, unsigned int fake_size)
{
        int total_dma_data_written = 0;
        u8 *p_dma_buffer = dma_buffer;
        u8 header[SDW_CDNS_BRA_HDR];
        unsigned int start_register;
        unsigned int data_size;
        int dma_data_written;
        u8 counter;
        int ret;
        int i;

        counter = CDNS_BPT_ROLLING_COUNTER_START;

        header[0] = 0;                  /* read command: BIT(1) cleared */
        header[0] |= GENMASK(7, 6);     /* header is active */
        header[0] |= (dev_num << 2);

        for (i = 0; i < num_sec; i++) {
                start_register = sec[i].addr;
                data_size = sec[i].len;
                while (data_size >= data_per_frame) {
                        header[1] = data_per_frame;
                        header[2] = start_register >> 24 & 0xFF;
                        header[3] = start_register >> 16 & 0xFF;
                        header[4] = start_register >> 8 & 0xFF;
                        header[5] = start_register >> 0 & 0xFF;

                        ret = sdw_cdns_prepare_read_pd0_buffer(header, SDW_CDNS_BRA_HDR,
                                                               p_dma_buffer, dma_buffer_size,
                                                               &dma_data_written, counter);
                        if (ret < 0)
                                return ret;

                        counter++;

                        data_size -= data_per_frame;

                        p_dma_buffer += dma_data_written;
                        dma_buffer_size -= dma_data_written;
                        total_dma_data_written += dma_data_written;

                        start_register += data_per_frame;
                }

                if (data_size) {
                        header[1] = data_size;
                        header[2] = start_register >> 24 & 0xFF;
                        header[3] = start_register >> 16 & 0xFF;
                        header[4] = start_register >> 8 & 0xFF;
                        header[5] = start_register >> 0 & 0xFF;

                        ret = sdw_cdns_prepare_read_pd0_buffer(header, SDW_CDNS_BRA_HDR,
                                                               p_dma_buffer, dma_buffer_size,
                                                               &dma_data_written, counter);
                        if (ret < 0)
                                return ret;

                        counter++;

                        p_dma_buffer += dma_data_written;
                        dma_buffer_size -= dma_data_written;
                        total_dma_data_written += dma_data_written;
                }
        }

        /* Add fake frame */
        header[0] &= ~GENMASK(7, 6);    /* Set inactive flag in BPT/BRA frame heade */
        while (fake_size >= data_per_frame) {
                header[1] = data_per_frame;
                ret = sdw_cdns_prepare_read_pd0_buffer(header, SDW_CDNS_BRA_HDR, p_dma_buffer,
                                                       dma_buffer_size, &dma_data_written,
                                                       counter);
                if (ret < 0)
                        return ret;

                counter++;

                fake_size -= data_per_frame;
                p_dma_buffer += dma_data_written;
                dma_buffer_size -= dma_data_written;
                total_dma_data_written += dma_data_written;
        }

        if (fake_size) {
                header[1] = fake_size;
                ret = sdw_cdns_prepare_read_pd0_buffer(header, SDW_CDNS_BRA_HDR, p_dma_buffer,
                                                       dma_buffer_size, &dma_data_written,
                                                       counter);
                if (ret < 0)
                        return ret;

                counter++;

                p_dma_buffer += dma_data_written;
                dma_buffer_size -= dma_data_written;
                total_dma_data_written += dma_data_written;
        }

        *dma_buffer_total_bytes = total_dma_data_written;

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_prepare_read_dma_buffer);

static int check_counter(u32 val, u8 counter)
{
        u8 frame;

        frame = (val >> 24) & GENMASK(3, 0);
        if (counter != frame)
                return -EIO;
        return 0;
}

static int check_response(u32 val)
{
        u8 response;

        response = (val >> 3) & GENMASK(1, 0);
        if (response == 0) /* Ignored */
                return -ENODATA;
        if (response != 1) /* ACK */
                return -EIO;

        return 0;
}

static int check_frame_start(u32 header, u8 counter)
{
        int ret;

        /* check frame_start marker */
        if (!(header & BIT(31)))
                return -EIO;

        ret = check_counter(header, counter);
        if (ret < 0)
                return ret;

        return check_response(header);
}

static int check_frame_end(u32 footer)
{
        /* check frame_end marker */
        if (!(footer & BIT(30)))
                return -EIO;

        return check_response(footer);
}

int sdw_cdns_check_write_response(struct device *dev, u8 *dma_buffer,
                                  int dma_buffer_size, int num_frames)
{
        u32 *p_data;
        int counter;
        u32 header;
        u32 footer;
        int ret;
        int i;

        /* paranoia check on buffer size */
        if (dma_buffer_size != num_frames * 8)
                return -EINVAL;

        counter = CDNS_BPT_ROLLING_COUNTER_START;
        p_data = (u32 *)dma_buffer;

        for (i = 0; i < num_frames; i++) {
                header = *p_data++;
                footer = *p_data++;

                ret = check_frame_start(header, counter);
                if (ret < 0) {
                        dev_err(dev, "%s: bad frame %d/%d start header %x\n",
                                __func__, i + 1, num_frames, header);
                        return ret;
                }

                ret = check_frame_end(footer);
                if (ret < 0) {
                        dev_err(dev, "%s: bad frame %d/%d end footer %x\n",
                                __func__, i + 1, num_frames, footer);
                        return ret;
                }

                counter++;
                counter &= GENMASK(3, 0);
        }
        return 0;
}
EXPORT_SYMBOL(sdw_cdns_check_write_response);

static u8 extract_read_data(u32 *data, int num_bytes, u8 *buffer)
{
        u32 val;
        int i;
        u8 crc;
        u8 b0;
        u8 b1;

        crc = SDW_CRC8_SEED;

        /* process two bytes at a time */
        for (i = 0; i < num_bytes / 2; i++) {
                val = *data++;

                b0 = val & 0xff;
                b1 = (val >> 8) & 0xff;

                *buffer++ = b0;
                crc = crc8(sdw_crc8_lookup_msb, &b0, 1, crc);

                *buffer++ = b1;
                crc = crc8(sdw_crc8_lookup_msb, &b1, 1, crc);
        }
        /* handle remaining byte if it exists */
        if (num_bytes & 1) {
                val = *data;

                b0 = val & 0xff;

                *buffer++ = b0;
                crc = crc8(sdw_crc8_lookup_msb, &b0, 1, crc);
        }
        return crc;
}

int sdw_cdns_check_read_response(struct device *dev, u8 *dma_buffer, int dma_buffer_size,
                                 struct sdw_bpt_section *sec, int num_sec, int num_frames,
                                 int data_per_frame)
{
        int total_num_bytes = 0;
        int buffer_size = 0;
        int sec_index;
        u32 *p_data;
        u8 *p_buf;
        int counter;
        u32 header;
        u32 footer;
        u8 expected_crc;
        u8 crc;
        int len;
        int ret;
        int i;

        counter = CDNS_BPT_ROLLING_COUNTER_START;
        p_data = (u32 *)dma_buffer;

        sec_index = 0;
        p_buf = sec[sec_index].buf;
        buffer_size = sec[sec_index].len;

        for (i = 0; i < num_frames; i++) {
                header = *p_data++;

                ret = check_frame_start(header, counter);
                if (ret < 0) {
                        dev_err(dev, "%s: bad frame %d/%d start header %x\n",
                                __func__, i + 1, num_frames, header);
                        return ret;
                }

                len = data_per_frame;
                if (total_num_bytes + data_per_frame > buffer_size)
                        len = buffer_size - total_num_bytes;

                crc = extract_read_data(p_data, len, p_buf);

                p_data += (len + 1) / 2;
                expected_crc = *p_data++ & 0xff;

                if (crc != expected_crc) {
                        dev_err(dev, "%s: bad frame %d/%d crc %#x expected %#x\n",
                                __func__, i + 1, num_frames, crc, expected_crc);
                        return -EIO;
                }

                p_buf += len;
                total_num_bytes += len;

                footer = *p_data++;
                ret = check_frame_end(footer);
                if (ret < 0) {
                        dev_err(dev, "%s: bad frame %d/%d end footer %x\n",
                                __func__, i + 1, num_frames, footer);
                        return ret;
                }

                counter++;
                counter &= GENMASK(3, 0);

                if (buffer_size == total_num_bytes && (i + 1) < num_frames) {
                        sec_index++;
                        if (sec_index >= num_sec) {
                                dev_err(dev, "%s: incorrect section index %d i %d\n",
                                        __func__, sec_index, i);
                                return -EINVAL;
                        }
                        p_buf = sec[sec_index].buf;
                        buffer_size = sec[sec_index].len;
                        total_num_bytes = 0;
                }
        }
        return 0;
}
EXPORT_SYMBOL(sdw_cdns_check_read_response);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("Cadence Soundwire Library");