// 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/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/soundwire/sdw_registers.h>
#include <linux/soundwire/sdw.h>
#include <sound/pcm_params.h>
#include <sound/soc.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_MCMD_RETRY              GENMASK(27, 24)
#define CDNS_MCP_CONFIG_MPREQ_DELAY             GENMASK(20, 16)
#define CDNS_MCP_CONFIG_MMASTER                 BIT(7)
#define CDNS_MCP_CONFIG_BUS_REL                 BIT(6)
#define CDNS_MCP_CONFIG_SNIFFER                 BIT(5)
#define CDNS_MCP_CONFIG_SSPMOD                  BIT(4)
#define CDNS_MCP_CONFIG_CMD                     BIT(3)
#define CDNS_MCP_CONFIG_OP                      GENMASK(2, 0)
#define CDNS_MCP_CONFIG_OP_NORMAL               0

#define CDNS_MCP_CONTROL                        0x4

#define CDNS_MCP_CONTROL_RST_DELAY              GENMASK(10, 8)
#define CDNS_MCP_CONTROL_CMD_RST                BIT(7)
#define CDNS_MCP_CONTROL_SOFT_RST               BIT(6)
#define CDNS_MCP_CONTROL_SW_RST                 BIT(5)
#define CDNS_MCP_CONTROL_HW_RST                 BIT(4)
#define CDNS_MCP_CONTROL_CLK_PAUSE              BIT(3)
#define CDNS_MCP_CONTROL_CLK_STOP_CLR           BIT(2)
#define CDNS_MCP_CONTROL_CMD_ACCEPT             BIT(1)
#define CDNS_MCP_CONTROL_BLOCK_WAKEUP           BIT(0)

#define CDNS_MCP_CMDCTRL                        0x8
#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_OFFSET         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_MCP_CMD_BASE                       0x80
#define CDNS_MCP_RESP_BASE                      0x80
#define CDNS_MCP_CMD_LEN                        0x20
#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_H                 GENMASK(23, 16)
#define CDNS_MCP_CMD_REG_ADDR_L                 GENMASK(15, 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_DIRN                      BIT(7)
#define CDNS_PORTCTRL_BANK_INVERT               BIT(8)

#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                         2000

#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 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 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;
}

/*
 * 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;
        char *buf;
        ssize_t ret;
        int num_ports;
        int i, j;

        buf = 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);
        kfree(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");

/**
 * 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);
}
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_dbg_ratelimited(cdns->dev, "Msg Ack not received\n");
                        if (cdns->response_buf[i] & CDNS_MCP_RESP_NACK) {
                                nack = 1;
                                dev_err_ratelimited(cdns->dev, "Msg NACK received\n");
                        }
                }
        }

        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;
        }

        /* fill response */
        for (i = 0; i < count; i++)
                msg->buf[i + offset] = cdns->response_buf[i] >>
                                SDW_REG_SHIFT(CDNS_MCP_RESP_RDATA);

        return SDW_CMD_OK;
}

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_MCP_CMD_BASE;
        addr = msg->addr;

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

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

                data |= msg->ssp_sync << SDW_REG_SHIFT(CDNS_MCP_CMD_SSP_TAG);
                cdns_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;
                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] = msg->dev_num << SDW_REG_SHIFT(CDNS_MCP_CMD_DEV_ADDR);
        data[0] |= 0x3 << SDW_REG_SHIFT(CDNS_MCP_CMD_COMMAND);
        data[1] = data[0];

        data[0] |= SDW_SCP_ADDRPAGE1 << SDW_REG_SHIFT(CDNS_MCP_CMD_REG_ADDR_L);
        data[1] |= SDW_SCP_ADDRPAGE2 << SDW_REG_SHIFT(CDNS_MCP_CMD_REG_ADDR_L);

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

        base = CDNS_MCP_CMD_BASE;
        cdns_writel(cdns, base, data[0]);
        base += CDNS_MCP_CMD_WORD_LEN;
        cdns_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 < 0)
                        goto exit;
        }

        if (!(msg->len % CDNS_MCP_CMD_LEN))
                goto exit;

        ret = _cdns_xfer_msg(cdns, msg, cmd, i * CDNS_MCP_CMD_LEN,
                             msg->len % CDNS_MCP_CMD_LEN, false);

exit:
        return ret;
}
EXPORT_SYMBOL(cdns_xfer_msg);

enum sdw_command_response
cdns_xfer_msg_defer(struct sdw_bus *bus,
                    struct sdw_msg *msg, struct sdw_defer *defer)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        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;

        cdns->defer = defer;
        cdns->defer->length = msg->len;

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

enum sdw_command_response
cdns_reset_page_addr(struct sdw_bus *bus, unsigned int dev_num)
{
        struct sdw_cdns *cdns = bus_to_cdns(bus);
        struct sdw_msg msg;

        /* Create dummy message with valid device number */
        memset(&msg, 0, sizeof(msg));
        msg.dev_num = dev_num;

        return cdns_program_scp_addr(cdns, &msg);
}
EXPORT_SYMBOL(cdns_reset_page_addr);

/*
 * IRQ handling
 */

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

        num_resp = cdns_readl(cdns, CDNS_MCP_FIFOSTAT);
        num_resp &= CDNS_MCP_RX_FIFO_AVAIL;

        cmd_base = CDNS_MCP_CMD_BASE;

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

static int cdns_update_slave_status(struct sdw_cdns *cdns,
                                    u32 slave0, u32 slave1)
{
        enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
        bool is_slave = false;
        u64 slave;
        u32 mask;
        int i, set_status;

        /* combine the two status */
        slave = ((u64)slave1 << 32) | slave0;
        memset(status, 0, sizeof(status));

        for (i = 0; i <= SDW_MAX_DEVICES; i++) {
                mask = (slave >> (i * CDNS_MCP_SLAVE_STATUS_NUM)) &
                                CDNS_MCP_SLAVE_STATUS_BITS;
                if (!mask)
                        continue;

                is_slave = true;
                set_status = 0;

                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++;
                }

                /* first check if Slave reported multiple status */
                if (set_status > 1) {
                        u32 val;

                        dev_warn_ratelimited(cdns->dev,
                                             "Slave %d reported multiple Status: %d\n",
                                             i, mask);

                        /* check latest status extracted from PING commands */
                        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;
                        }

                        dev_warn_ratelimited(cdns->dev,
                                             "Slave %d status updated to %d\n",
                                             i, status[i]);

                }
        }

        if (is_slave)
                return sdw_handle_slave_status(&cdns->bus, status);

        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;
        int ret = IRQ_HANDLED;

        /* 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) {
                cdns_read_response(cdns);

                if (cdns->defer) {
                        cdns_fill_msg_resp(cdns, cdns->defer->msg,
                                           cdns->defer->length, 0);
                        complete(&cdns->defer->complete);
                        cdns->defer = NULL;
                } 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 (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;
                ret = IRQ_WAKE_THREAD;
        }

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

/**
 * sdw_cdns_thread() - Cadence irq thread handler
 * @irq: irq number
 * @dev_id: irq context
 */
irqreturn_t sdw_cdns_thread(int irq, void *dev_id)
{
        struct sdw_cdns *cdns = dev_id;
        u32 slave0, slave1;

        dev_dbg_ratelimited(cdns->dev, "Slave status change\n");

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

        cdns_update_slave_status(cdns, slave0, slave1);
        cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT0, slave0);
        cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT1, slave1);

        /* clear and unmask Slave interrupt now */
        cdns_writel(cdns, CDNS_MCP_INTSTAT, CDNS_MCP_INT_SLAVE_MASK);
        cdns_updatel(cdns, CDNS_MCP_INTMASK,
                     CDNS_MCP_INT_SLAVE_MASK, CDNS_MCP_INT_SLAVE_MASK);

        return IRQ_HANDLED;
}
EXPORT_SYMBOL(sdw_cdns_thread);

/*
 * 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)
{
        /* program maximum length reset to be safe */
        cdns_updatel(cdns, CDNS_MCP_CONTROL,
                     CDNS_MCP_CONTROL_RST_DELAY,
                     CDNS_MCP_CONTROL_RST_DELAY);

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

        /* commit changes */
        cdns_updatel(cdns, CDNS_MCP_CONFIG_UPDATE,
                     CDNS_MCP_CONFIG_UPDATE_BIT,
                     CDNS_MCP_CONFIG_UPDATE_BIT);

        /* don't wait here */
        return 0;

}
EXPORT_SYMBOL(sdw_cdns_exit_reset);

/**
 * sdw_cdns_enable_slave_interrupt() - 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;

        /* no detection of port interrupts for now */

        /* 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_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, u32 pdi_offset)
{
        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 + pdi_offset;
        }

        *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 offset;
        int ret;

        cdns->pcm.num_bd = config.pcm_bd;
        cdns->pcm.num_in = config.pcm_in;
        cdns->pcm.num_out = config.pcm_out;
        cdns->pdm.num_bd = config.pdm_bd;
        cdns->pdm.num_in = config.pdm_in;
        cdns->pdm.num_out = config.pdm_out;

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

        /* we allocate PDI0 and PDI1 which are used for Bulk */
        offset = 0;

        ret = cdns_allocate_pdi(cdns, &stream->bd,
                                stream->num_bd, offset);
        if (ret)
                return ret;

        offset += stream->num_bd;

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

        offset += stream->num_in;

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

        /* Allocate PDIs for PDMs */
        stream = &cdns->pdm;
        ret = cdns_allocate_pdi(cdns, &stream->bd,
                                stream->num_bd, offset);
        if (ret)
                return ret;

        offset += stream->num_bd;

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

        offset += stream->num_in;

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

        if (ret)
                return ret;

        /* Update total number of PDM 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) & CDNS_MCP_FRAME_SHAPE_COL_MASK;

        val = (r << CDNS_MCP_FRAME_SHAPE_ROW_OFFSET) | c;

        return val;
}

static void 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;

        /* Set clock divider */
        divider = (prop->mclk_freq / prop->max_clk_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);

        /*
         * 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);
}

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

        cdns_init_clock_ctrl(cdns);

        /* 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_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT,
                     CDNS_MCP_CONTROL_CMD_ACCEPT);

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

        /* enable bus operations with clock and data */
        val &= ~CDNS_MCP_CONFIG_OP;
        val |= CDNS_MCP_CONFIG_OP_NORMAL;

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

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

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

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

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

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

        cdns_writel(cdns, CDNS_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 = 0, dpn_config_off;

        if (bank)
                dpn_config_off = CDNS_DPN_B1_CONFIG(p_params->num);
        else
                dpn_config_off = CDNS_DPN_B0_CONFIG(p_params->num);

        dpn_config = cdns_readl(cdns, dpn_config_off);

        dpn_config |= ((p_params->bps - 1) <<
                                SDW_REG_SHIFT(CDNS_DPN_CONFIG_WL));
        dpn_config |= (p_params->flow_mode <<
                                SDW_REG_SHIFT(CDNS_DPN_CONFIG_PORT_FLOW));
        dpn_config |= (p_params->data_mode <<
                                SDW_REG_SHIFT(CDNS_DPN_CONFIG_PORT_DAT));

        cdns_writel(cdns, dpn_config_off, 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_offsetctrl = 0, dpn_offsetctrl_off;
        int dpn_config = 0, dpn_config_off;
        int dpn_hctrl = 0, dpn_hctrl_off;
        int num = t_params->port_num;
        int dpn_samplectrl_off;

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

        if (bank) {
                dpn_config_off = CDNS_DPN_B1_CONFIG(num);
                dpn_samplectrl_off = CDNS_DPN_B1_SAMPLE_CTRL(num);
                dpn_hctrl_off = CDNS_DPN_B1_HCTRL(num);
                dpn_offsetctrl_off = CDNS_DPN_B1_OFFSET_CTRL(num);
        } else {
                dpn_config_off = CDNS_DPN_B0_CONFIG(num);
                dpn_samplectrl_off = CDNS_DPN_B0_SAMPLE_CTRL(num);
                dpn_hctrl_off = CDNS_DPN_B0_HCTRL(num);
                dpn_offsetctrl_off = CDNS_DPN_B0_OFFSET_CTRL(num);
        }

        dpn_config = cdns_readl(cdns, dpn_config_off);

        dpn_config |= (t_params->blk_grp_ctrl <<
                                SDW_REG_SHIFT(CDNS_DPN_CONFIG_BGC));
        dpn_config |= (t_params->blk_pkg_mode <<
                                SDW_REG_SHIFT(CDNS_DPN_CONFIG_BPM));
        cdns_writel(cdns, dpn_config_off, dpn_config);

        dpn_offsetctrl |= (t_params->offset1 <<
                                SDW_REG_SHIFT(CDNS_DPN_OFFSET_CTRL_1));
        dpn_offsetctrl |= (t_params->offset2 <<
                                SDW_REG_SHIFT(CDNS_DPN_OFFSET_CTRL_2));
        cdns_writel(cdns, dpn_offsetctrl_off,  dpn_offsetctrl);

        dpn_hctrl |= (t_params->hstart <<
                                SDW_REG_SHIFT(CDNS_DPN_HCTRL_HSTART));
        dpn_hctrl |= (t_params->hstop << SDW_REG_SHIFT(CDNS_DPN_HCTRL_HSTOP));
        dpn_hctrl |= (t_params->lane_ctrl <<
                                SDW_REG_SHIFT(CDNS_DPN_HCTRL_LCTRL));

        cdns_writel(cdns, dpn_hctrl_off, dpn_hctrl);
        cdns_writel(cdns, dpn_samplectrl_off, (t_params->sample_interval - 1));

        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;

        /* 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_updatel(cdns, CDNS_MCP_CONTROL,
                             CDNS_MCP_CONTROL_BLOCK_WAKEUP,
                             CDNS_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;
                }
        }

        /*
         * This CMD_ACCEPT should be used when there are no devices
         * attached on the link when entering clock stop mode. If this is
         * not set and there is a broadcast write then the command ignored
         * will be treated as a failure
         */
        if (!slave_present)
                cdns_updatel(cdns, CDNS_MCP_CONTROL,
                             CDNS_MCP_CONTROL_CMD_ACCEPT,
                             CDNS_MCP_CONTROL_CMD_ACCEPT);
        else
                cdns_updatel(cdns, CDNS_MCP_CONTROL,
                             CDNS_MCP_CONTROL_CMD_ACCEPT, 0);

        /* 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 */
        ret = sdw_bus_prep_clk_stop(&cdns->bus);
        if (ret < 0) {
                dev_err(cdns->dev, "prepare clock stop failed %d", 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", 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_updatel(cdns, CDNS_MCP_CONTROL,
                     CDNS_MCP_CONTROL_BLOCK_WAKEUP, 0);

        /*
         * clear CMD_ACCEPT so that the command ignored
         * will be treated as a failure during a broadcast write
         */
        cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT, 0);

        if (!bus_reset) {

                /* enable bus operations with clock and data */
                cdns_updatel(cdns, CDNS_MCP_CONFIG,
                             CDNS_MCP_CONFIG_OP,
                             CDNS_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;

        return 0;
}
EXPORT_SYMBOL(sdw_cdns_probe);

int cdns_set_sdw_stream(struct snd_soc_dai *dai,
                        void *stream, bool pcm, int direction)
{
        struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai);
        struct sdw_cdns_dma_data *dma;

        dma = kzalloc(sizeof(*dma), GFP_KERNEL);
        if (!dma)
                return -ENOMEM;

        if (pcm)
                dma->stream_type = SDW_STREAM_PCM;
        else
                dma->stream_type = SDW_STREAM_PDM;

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

        dma->stream = stream;

        if (direction == SNDRV_PCM_STREAM_PLAYBACK)
                dai->playback_dma_data = dma;
        else
                dai->capture_dma_data = dma;

        return 0;
}
EXPORT_SYMBOL(cdns_set_sdw_stream);

/**
 * cdns_find_pdi() - Find a free PDI
 *
 * @cdns: Cadence instance
 * @offset: Starting offset
 * @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 offset,
                                          unsigned int num,
                                          struct sdw_cdns_pdi *pdi,
                                          int dai_id)
{
        int i;

        for (i = offset; i < offset + 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;

        offset = CDNS_PORTCTRL + pdi->num * CDNS_PORT_OFFSET;
        cdns_updatel(cdns, offset, CDNS_PORTCTRL_DIRN, val);

        val = pdi->num;
        val |= CDNS_PDI_CONFIG_SOFT_RESET;
        val |= ((1 << ch) - 1) << SDW_REG_SHIFT(CDNS_PDI_CONFIG_CHANNEL);
        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, 0, stream->num_in, stream->in,
                                    dai_id);
        else
                pdi = cdns_find_pdi(cdns, 0, 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, 2, 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);

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