root/drivers/memstick/host/rtsx_usb_ms.c
// SPDX-License-Identifier: GPL-2.0-only
/* Realtek USB Memstick Card Interface driver
 *
 * Copyright(c) 2009-2013 Realtek Semiconductor Corp. All rights reserved.
 *
 * Author:
 *   Roger Tseng <rogerable@realtek.com>
 */

#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>
#include <linux/memstick.h>
#include <linux/kthread.h>
#include <linux/rtsx_usb.h>
#include <linux/pm_runtime.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/unaligned.h>

struct rtsx_usb_ms {
        struct platform_device  *pdev;
        struct rtsx_ucr *ucr;
        struct memstick_host    *msh;
        struct memstick_request *req;

        struct mutex            host_mutex;
        struct work_struct      handle_req;
        struct delayed_work     poll_card;

        u8                      ssc_depth;
        unsigned int            clock;
        int                     power_mode;
        unsigned char           ifmode;
        bool                    eject;
        bool                    system_suspending;
};

static inline struct device *ms_dev(struct rtsx_usb_ms *host)
{
        return &(host->pdev->dev);
}

static inline void ms_clear_error(struct rtsx_usb_ms *host)
{
        struct rtsx_ucr *ucr = host->ucr;
        rtsx_usb_ep0_write_register(ucr, CARD_STOP,
                                  MS_STOP | MS_CLR_ERR,
                                  MS_STOP | MS_CLR_ERR);

        rtsx_usb_clear_dma_err(ucr);
        rtsx_usb_clear_fsm_err(ucr);
}

#ifdef DEBUG

static void ms_print_debug_regs(struct rtsx_usb_ms *host)
{
        struct rtsx_ucr *ucr = host->ucr;
        u16 i;
        u8 *ptr;

        /* Print MS host internal registers */
        rtsx_usb_init_cmd(ucr);

        /* MS_CFG to MS_INT_REG */
        for (i = 0xFD40; i <= 0xFD44; i++)
                rtsx_usb_add_cmd(ucr, READ_REG_CMD, i, 0, 0);

        /* CARD_SHARE_MODE to CARD_GPIO */
        for (i = 0xFD51; i <= 0xFD56; i++)
                rtsx_usb_add_cmd(ucr, READ_REG_CMD, i, 0, 0);

        /* CARD_PULL_CTLx */
        for (i = 0xFD60; i <= 0xFD65; i++)
                rtsx_usb_add_cmd(ucr, READ_REG_CMD, i, 0, 0);

        /* CARD_DATA_SOURCE, CARD_SELECT, CARD_CLK_EN, CARD_PWR_CTL */
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, CARD_DATA_SOURCE, 0, 0);
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, CARD_SELECT, 0, 0);
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, CARD_CLK_EN, 0, 0);
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, CARD_PWR_CTL, 0, 0);

        rtsx_usb_send_cmd(ucr, MODE_CR, 100);
        rtsx_usb_get_rsp(ucr, 21, 100);

        ptr = ucr->rsp_buf;
        for (i = 0xFD40; i <= 0xFD44; i++)
                dev_dbg(ms_dev(host), "0x%04X: 0x%02x\n", i, *(ptr++));
        for (i = 0xFD51; i <= 0xFD56; i++)
                dev_dbg(ms_dev(host), "0x%04X: 0x%02x\n", i, *(ptr++));
        for (i = 0xFD60; i <= 0xFD65; i++)
                dev_dbg(ms_dev(host), "0x%04X: 0x%02x\n", i, *(ptr++));

        dev_dbg(ms_dev(host), "0x%04X: 0x%02x\n", CARD_DATA_SOURCE, *(ptr++));
        dev_dbg(ms_dev(host), "0x%04X: 0x%02x\n", CARD_SELECT, *(ptr++));
        dev_dbg(ms_dev(host), "0x%04X: 0x%02x\n", CARD_CLK_EN, *(ptr++));
        dev_dbg(ms_dev(host), "0x%04X: 0x%02x\n", CARD_PWR_CTL, *(ptr++));
}

#else

static void ms_print_debug_regs(struct rtsx_usb_ms *host)
{
}

#endif

static int ms_pull_ctl_disable_lqfp48(struct rtsx_ucr *ucr)
{
        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL1, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL2, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL3, 0xFF, 0x95);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL4, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL5, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL6, 0xFF, 0xA5);

        return rtsx_usb_send_cmd(ucr, MODE_C, 100);
}

static int ms_pull_ctl_disable_qfn24(struct rtsx_ucr *ucr)
{
        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL1, 0xFF, 0x65);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL2, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL3, 0xFF, 0x95);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL4, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL5, 0xFF, 0x56);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL6, 0xFF, 0x59);

        return rtsx_usb_send_cmd(ucr, MODE_C, 100);
}

static int ms_pull_ctl_enable_lqfp48(struct rtsx_ucr *ucr)
{
        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL1, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL2, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL3, 0xFF, 0x95);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL4, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL5, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL6, 0xFF, 0xA5);

        return rtsx_usb_send_cmd(ucr, MODE_C, 100);
}

static int ms_pull_ctl_enable_qfn24(struct rtsx_ucr *ucr)
{
        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL1, 0xFF, 0x65);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL2, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL3, 0xFF, 0x95);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL4, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL5, 0xFF, 0x55);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL6, 0xFF, 0x59);

        return rtsx_usb_send_cmd(ucr, MODE_C, 100);
}

static int ms_power_on(struct rtsx_usb_ms *host)
{
        struct rtsx_ucr *ucr = host->ucr;
        int err;

        dev_dbg(ms_dev(host), "%s\n", __func__);

        rtsx_usb_init_cmd(ucr);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_SELECT, 0x07, MS_MOD_SEL);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_SHARE_MODE,
                        CARD_SHARE_MASK, CARD_SHARE_MS);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_CLK_EN,
                        MS_CLK_EN, MS_CLK_EN);
        err = rtsx_usb_send_cmd(ucr, MODE_C, 100);
        if (err < 0)
                return err;

        if (CHECK_PKG(ucr, LQFP48))
                err = ms_pull_ctl_enable_lqfp48(ucr);
        else
                err = ms_pull_ctl_enable_qfn24(ucr);
        if (err < 0)
                return err;

        err = rtsx_usb_write_register(ucr, CARD_PWR_CTL,
                        POWER_MASK, PARTIAL_POWER_ON);
        if (err)
                return err;

        usleep_range(800, 1000);

        rtsx_usb_init_cmd(ucr);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL,
                        POWER_MASK, POWER_ON);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_OE,
                        MS_OUTPUT_EN, MS_OUTPUT_EN);

        return rtsx_usb_send_cmd(ucr, MODE_C, 100);
}

static int ms_power_off(struct rtsx_usb_ms *host)
{
        struct rtsx_ucr *ucr = host->ucr;
        int err;

        dev_dbg(ms_dev(host), "%s\n", __func__);

        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_CLK_EN, MS_CLK_EN, 0);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_OE, MS_OUTPUT_EN, 0);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL,
                        POWER_MASK, POWER_OFF);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL,
                        POWER_MASK | LDO3318_PWR_MASK, POWER_OFF | LDO_SUSPEND);
        err = rtsx_usb_send_cmd(ucr, MODE_C, 100);
        if (err < 0)
                return err;

        if (CHECK_PKG(ucr, LQFP48))
                return ms_pull_ctl_disable_lqfp48(ucr);

        return ms_pull_ctl_disable_qfn24(ucr);
}

static int ms_transfer_data(struct rtsx_usb_ms *host, unsigned char data_dir,
                u8 tpc, u8 cfg, struct scatterlist *sg)
{
        struct rtsx_ucr *ucr = host->ucr;
        int err;
        unsigned int length = sg->length;
        u16 sec_cnt = (u16)(length / 512);
        u8 trans_mode, dma_dir, flag;
        unsigned int pipe;
        struct memstick_dev *card = host->msh->card;

        dev_dbg(ms_dev(host), "%s: tpc = 0x%02x, data_dir = %s, length = %d\n",
                        __func__, tpc, (data_dir == READ) ? "READ" : "WRITE",
                        length);

        if (data_dir == READ) {
                flag = MODE_CDIR;
                dma_dir = DMA_DIR_FROM_CARD;
                if (card->id.type != MEMSTICK_TYPE_PRO)
                        trans_mode = MS_TM_NORMAL_READ;
                else
                        trans_mode = MS_TM_AUTO_READ;
                pipe = usb_rcvbulkpipe(ucr->pusb_dev, EP_BULK_IN);
        } else {
                flag = MODE_CDOR;
                dma_dir = DMA_DIR_TO_CARD;
                if (card->id.type != MEMSTICK_TYPE_PRO)
                        trans_mode = MS_TM_NORMAL_WRITE;
                else
                        trans_mode = MS_TM_AUTO_WRITE;
                pipe = usb_sndbulkpipe(ucr->pusb_dev, EP_BULK_OUT);
        }

        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TPC, 0xFF, tpc);
        if (card->id.type == MEMSTICK_TYPE_PRO) {
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_SECTOR_CNT_H,
                                0xFF, (u8)(sec_cnt >> 8));
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_SECTOR_CNT_L,
                                0xFF, (u8)sec_cnt);
        }
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TRANS_CFG, 0xFF, cfg);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MC_DMA_TC3,
                        0xFF, (u8)(length >> 24));
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MC_DMA_TC2,
                        0xFF, (u8)(length >> 16));
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MC_DMA_TC1,
                        0xFF, (u8)(length >> 8));
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MC_DMA_TC0, 0xFF,
                        (u8)length);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MC_DMA_CTL,
                        0x03 | DMA_PACK_SIZE_MASK, dma_dir | DMA_EN | DMA_512);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_DATA_SOURCE,
                        0x01, RING_BUFFER);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TRANSFER,
                        0xFF, MS_TRANSFER_START | trans_mode);
        rtsx_usb_add_cmd(ucr, CHECK_REG_CMD, MS_TRANSFER,
                        MS_TRANSFER_END, MS_TRANSFER_END);

        err = rtsx_usb_send_cmd(ucr, flag | STAGE_MS_STATUS, 100);
        if (err)
                return err;

        err = rtsx_usb_transfer_data(ucr, pipe, sg, length,
                        1, NULL, 10000);
        if (err)
                goto err_out;

        err = rtsx_usb_get_rsp(ucr, 3, 15000);
        if (err)
                goto err_out;

        if (ucr->rsp_buf[0] & MS_TRANSFER_ERR ||
            ucr->rsp_buf[1] & (MS_CRC16_ERR | MS_RDY_TIMEOUT)) {
                err = -EIO;
                goto err_out;
        }
        return 0;
err_out:
        ms_clear_error(host);
        return err;
}

static int ms_write_bytes(struct rtsx_usb_ms *host, u8 tpc,
                u8 cfg, u8 cnt, u8 *data, u8 *int_reg)
{
        struct rtsx_ucr *ucr = host->ucr;
        int err, i;

        dev_dbg(ms_dev(host), "%s: tpc = 0x%02x\n", __func__, tpc);

        rtsx_usb_init_cmd(ucr);

        for (i = 0; i < cnt; i++)
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD,
                                PPBUF_BASE2 + i, 0xFF, data[i]);

        if (cnt % 2)
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD,
                                PPBUF_BASE2 + i, 0xFF, 0xFF);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TPC, 0xFF, tpc);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_BYTE_CNT, 0xFF, cnt);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TRANS_CFG, 0xFF, cfg);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_DATA_SOURCE,
                        0x01, PINGPONG_BUFFER);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TRANSFER,
                        0xFF, MS_TRANSFER_START | MS_TM_WRITE_BYTES);
        rtsx_usb_add_cmd(ucr, CHECK_REG_CMD, MS_TRANSFER,
                        MS_TRANSFER_END, MS_TRANSFER_END);
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, MS_TRANS_CFG, 0, 0);

        err = rtsx_usb_send_cmd(ucr, MODE_CR, 100);
        if (err)
                return err;

        err = rtsx_usb_get_rsp(ucr, 2, 5000);
        if (err || (ucr->rsp_buf[0] & MS_TRANSFER_ERR)) {
                u8 val;

                rtsx_usb_ep0_read_register(ucr, MS_TRANS_CFG, &val);
                dev_dbg(ms_dev(host), "MS_TRANS_CFG: 0x%02x\n", val);

                if (int_reg)
                        *int_reg = val & 0x0F;

                ms_print_debug_regs(host);

                ms_clear_error(host);

                if (!(tpc & 0x08)) {
                        if (val & MS_CRC16_ERR)
                                return -EIO;
                } else {
                        if (!(val & 0x80)) {
                                if (val & (MS_INT_ERR | MS_INT_CMDNK))
                                        return -EIO;
                        }
                }

                return -ETIMEDOUT;
        }

        if (int_reg)
                *int_reg = ucr->rsp_buf[1] & 0x0F;

        return 0;
}

static int ms_read_bytes(struct rtsx_usb_ms *host, u8 tpc,
                u8 cfg, u8 cnt, u8 *data, u8 *int_reg)
{
        struct rtsx_ucr *ucr = host->ucr;
        int err, i;
        u8 *ptr;

        dev_dbg(ms_dev(host), "%s: tpc = 0x%02x\n", __func__, tpc);

        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TPC, 0xFF, tpc);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_BYTE_CNT, 0xFF, cnt);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TRANS_CFG, 0xFF, cfg);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_DATA_SOURCE,
                        0x01, PINGPONG_BUFFER);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, MS_TRANSFER,
                        0xFF, MS_TRANSFER_START | MS_TM_READ_BYTES);
        rtsx_usb_add_cmd(ucr, CHECK_REG_CMD, MS_TRANSFER,
                        MS_TRANSFER_END, MS_TRANSFER_END);
        for (i = 0; i < cnt - 1; i++)
                rtsx_usb_add_cmd(ucr, READ_REG_CMD, PPBUF_BASE2 + i, 0, 0);
        if (cnt % 2)
                rtsx_usb_add_cmd(ucr, READ_REG_CMD, PPBUF_BASE2 + cnt, 0, 0);
        else
                rtsx_usb_add_cmd(ucr, READ_REG_CMD,
                                PPBUF_BASE2 + cnt - 1, 0, 0);

        rtsx_usb_add_cmd(ucr, READ_REG_CMD, MS_TRANS_CFG, 0, 0);

        err = rtsx_usb_send_cmd(ucr, MODE_CR, 100);
        if (err)
                return err;

        err = rtsx_usb_get_rsp(ucr, cnt + 2, 5000);
        if (err || (ucr->rsp_buf[0] & MS_TRANSFER_ERR)) {
                u8 val;

                rtsx_usb_ep0_read_register(ucr, MS_TRANS_CFG, &val);
                dev_dbg(ms_dev(host), "MS_TRANS_CFG: 0x%02x\n", val);

                if (int_reg && (host->ifmode != MEMSTICK_SERIAL))
                        *int_reg = val & 0x0F;

                ms_print_debug_regs(host);

                ms_clear_error(host);

                if (!(tpc & 0x08)) {
                        if (val & MS_CRC16_ERR)
                                return -EIO;
                } else {
                        if (!(val & 0x80)) {
                                if (val & (MS_INT_ERR | MS_INT_CMDNK))
                                        return -EIO;
                        }
                }

                return -ETIMEDOUT;
        }

        ptr = ucr->rsp_buf + 1;
        for (i = 0; i < cnt; i++)
                data[i] = *ptr++;


        if (int_reg && (host->ifmode != MEMSTICK_SERIAL))
                *int_reg = *ptr & 0x0F;

        return 0;
}

static int rtsx_usb_ms_issue_cmd(struct rtsx_usb_ms *host)
{
        struct memstick_request *req = host->req;
        int err = 0;
        u8 cfg = 0, int_reg;

        dev_dbg(ms_dev(host), "%s\n", __func__);

        if (req->need_card_int) {
                if (host->ifmode != MEMSTICK_SERIAL)
                        cfg = WAIT_INT;
        }

        if (req->long_data) {
                err = ms_transfer_data(host, req->data_dir,
                                req->tpc, cfg, &(req->sg));
        } else {
                if (req->data_dir == READ)
                        err = ms_read_bytes(host, req->tpc, cfg,
                                        req->data_len, req->data, &int_reg);
                else
                        err = ms_write_bytes(host, req->tpc, cfg,
                                        req->data_len, req->data, &int_reg);
        }
        if (err < 0)
                return err;

        if (req->need_card_int) {
                if (host->ifmode == MEMSTICK_SERIAL) {
                        err = ms_read_bytes(host, MS_TPC_GET_INT,
                                        NO_WAIT_INT, 1, &req->int_reg, NULL);
                        if (err < 0)
                                return err;
                } else {

                        if (int_reg & MS_INT_CMDNK)
                                req->int_reg |= MEMSTICK_INT_CMDNAK;
                        if (int_reg & MS_INT_BREQ)
                                req->int_reg |= MEMSTICK_INT_BREQ;
                        if (int_reg & MS_INT_ERR)
                                req->int_reg |= MEMSTICK_INT_ERR;
                        if (int_reg & MS_INT_CED)
                                req->int_reg |= MEMSTICK_INT_CED;
                }
                dev_dbg(ms_dev(host), "int_reg: 0x%02x\n", req->int_reg);
        }

        return 0;
}

static void rtsx_usb_ms_handle_req(struct work_struct *work)
{
        struct rtsx_usb_ms *host = container_of(work,
                        struct rtsx_usb_ms, handle_req);
        struct rtsx_ucr *ucr = host->ucr;
        struct memstick_host *msh = host->msh;
        int rc;

        if (!host->req) {
                pm_runtime_get_sync(ms_dev(host));
                do {
                        rc = memstick_next_req(msh, &host->req);
                        dev_dbg(ms_dev(host), "next req %d\n", rc);

                        if (!rc) {
                                mutex_lock(&ucr->dev_mutex);

                                if (rtsx_usb_card_exclusive_check(ucr,
                                                        RTSX_USB_MS_CARD))
                                        host->req->error = -EIO;
                                else
                                        host->req->error =
                                                rtsx_usb_ms_issue_cmd(host);

                                mutex_unlock(&ucr->dev_mutex);

                                dev_dbg(ms_dev(host), "req result %d\n",
                                                host->req->error);
                        }
                } while (!rc);
                pm_runtime_put_sync(ms_dev(host));
        }

}

static void rtsx_usb_ms_request(struct memstick_host *msh)
{
        struct rtsx_usb_ms *host = memstick_priv(msh);

        dev_dbg(ms_dev(host), "--> %s\n", __func__);

        if (!host->eject)
                schedule_work(&host->handle_req);
}

static int rtsx_usb_ms_set_param(struct memstick_host *msh,
                enum memstick_param param, int value)
{
        struct rtsx_usb_ms *host = memstick_priv(msh);
        struct rtsx_ucr *ucr = host->ucr;
        unsigned int clock = 0;
        u8 ssc_depth = 0;
        int err;

        dev_dbg(ms_dev(host), "%s: param = %d, value = %d\n",
                        __func__, param, value);

        pm_runtime_get_sync(ms_dev(host));
        mutex_lock(&ucr->dev_mutex);

        err = rtsx_usb_card_exclusive_check(ucr, RTSX_USB_MS_CARD);
        if (err)
                goto out;

        switch (param) {
        case MEMSTICK_POWER:
                if (value == host->power_mode)
                        break;

                if (value == MEMSTICK_POWER_ON) {
                        pm_runtime_get_noresume(ms_dev(host));
                        err = ms_power_on(host);
                        if (err)
                                pm_runtime_put_noidle(ms_dev(host));
                } else if (value == MEMSTICK_POWER_OFF) {
                        err = ms_power_off(host);
                        if (!err)
                                pm_runtime_put_noidle(ms_dev(host));
                } else
                        err = -EINVAL;
                if (!err)
                        host->power_mode = value;
                break;

        case MEMSTICK_INTERFACE:
                if (value == MEMSTICK_SERIAL) {
                        clock = 19000000;
                        ssc_depth = SSC_DEPTH_512K;
                        err = rtsx_usb_write_register(ucr, MS_CFG, 0x5A,
                                       MS_BUS_WIDTH_1 | PUSH_TIME_DEFAULT);
                        if (err < 0)
                                break;
                } else if (value == MEMSTICK_PAR4) {
                        clock = 39000000;
                        ssc_depth = SSC_DEPTH_1M;

                        err = rtsx_usb_write_register(ucr, MS_CFG, 0x5A,
                                        MS_BUS_WIDTH_4 | PUSH_TIME_ODD |
                                        MS_NO_CHECK_INT);
                        if (err < 0)
                                break;
                } else {
                        err = -EINVAL;
                        break;
                }

                err = rtsx_usb_switch_clock(ucr, clock,
                                ssc_depth, false, true, false);
                if (err < 0) {
                        dev_dbg(ms_dev(host), "switch clock failed\n");
                        break;
                }

                host->ssc_depth = ssc_depth;
                host->clock = clock;
                host->ifmode = value;
                break;
        default:
                err = -EINVAL;
                break;
        }
out:
        mutex_unlock(&ucr->dev_mutex);
        pm_runtime_put_sync(ms_dev(host));

        /* power-on delay */
        if (param == MEMSTICK_POWER && value == MEMSTICK_POWER_ON) {
                usleep_range(10000, 12000);

                if (!host->eject)
                        schedule_delayed_work(&host->poll_card, 100);
        }

        dev_dbg(ms_dev(host), "%s: return = %d\n", __func__, err);
        return err;
}

#ifdef CONFIG_PM_SLEEP
static int rtsx_usb_ms_suspend(struct device *dev)
{
        struct rtsx_usb_ms *host = dev_get_drvdata(dev);
        struct memstick_host *msh = host->msh;

        /* Since we use rtsx_usb's resume callback to runtime resume its
         * children to implement remote wakeup signaling, this causes
         * rtsx_usb_ms' runtime resume callback runs after its suspend
         * callback:
         * rtsx_usb_ms_suspend()
         * rtsx_usb_resume()
         *   -> rtsx_usb_ms_runtime_resume()
         *     -> memstick_detect_change()
         *
         * rtsx_usb_suspend()
         *
         * To avoid this, skip runtime resume/suspend if system suspend is
         * underway.
         */

        host->system_suspending = true;
        memstick_suspend_host(msh);

        return 0;
}

static int rtsx_usb_ms_resume(struct device *dev)
{
        struct rtsx_usb_ms *host = dev_get_drvdata(dev);
        struct memstick_host *msh = host->msh;

        memstick_resume_host(msh);
        host->system_suspending = false;

        return 0;
}
#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM
static int rtsx_usb_ms_runtime_suspend(struct device *dev)
{
        struct rtsx_usb_ms *host = dev_get_drvdata(dev);

        if (host->system_suspending)
                return 0;

        if (host->msh->card || host->power_mode != MEMSTICK_POWER_OFF)
                return -EAGAIN;

        return 0;
}

static int rtsx_usb_ms_runtime_resume(struct device *dev)
{
        struct rtsx_usb_ms *host = dev_get_drvdata(dev);


        if (host->system_suspending)
                return 0;

        memstick_detect_change(host->msh);

        return 0;
}
#endif /* CONFIG_PM */

static const struct dev_pm_ops rtsx_usb_ms_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(rtsx_usb_ms_suspend, rtsx_usb_ms_resume)
        SET_RUNTIME_PM_OPS(rtsx_usb_ms_runtime_suspend, rtsx_usb_ms_runtime_resume, NULL)
};


static void rtsx_usb_ms_poll_card(struct work_struct *work)
{
        struct rtsx_usb_ms *host = container_of(work, struct rtsx_usb_ms,
                        poll_card.work);
        struct rtsx_ucr *ucr = host->ucr;
        int err;
        u8 val;

        if (host->eject || host->power_mode != MEMSTICK_POWER_ON)
                return;

        pm_runtime_get_sync(ms_dev(host));
        mutex_lock(&ucr->dev_mutex);

        /* Check pending MS card changes */
        err = rtsx_usb_read_register(ucr, CARD_INT_PEND, &val);
        if (err) {
                mutex_unlock(&ucr->dev_mutex);
                goto poll_again;
        }

        /* Clear the pending */
        rtsx_usb_write_register(ucr, CARD_INT_PEND,
                        XD_INT | MS_INT | SD_INT,
                        XD_INT | MS_INT | SD_INT);

        mutex_unlock(&ucr->dev_mutex);

        if (val & MS_INT) {
                dev_dbg(ms_dev(host), "MS slot change detected\n");
                memstick_detect_change(host->msh);
        }

poll_again:
        pm_runtime_put_sync(ms_dev(host));

        if (!host->eject && host->power_mode == MEMSTICK_POWER_ON)
                schedule_delayed_work(&host->poll_card, 100);
}

static int rtsx_usb_ms_drv_probe(struct platform_device *pdev)
{
        struct memstick_host *msh;
        struct rtsx_usb_ms *host;
        struct rtsx_ucr *ucr;
        int err;

        ucr = usb_get_intfdata(to_usb_interface(pdev->dev.parent));
        if (!ucr)
                return -ENXIO;

        dev_dbg(&(pdev->dev),
                        "Realtek USB Memstick controller found\n");

        msh = memstick_alloc_host(sizeof(*host), &pdev->dev);
        if (!msh)
                return -ENOMEM;

        host = memstick_priv(msh);
        host->ucr = ucr;
        host->msh = msh;
        host->pdev = pdev;
        host->power_mode = MEMSTICK_POWER_OFF;
        platform_set_drvdata(pdev, host);

        mutex_init(&host->host_mutex);
        INIT_WORK(&host->handle_req, rtsx_usb_ms_handle_req);

        INIT_DELAYED_WORK(&host->poll_card, rtsx_usb_ms_poll_card);

        msh->request = rtsx_usb_ms_request;
        msh->set_param = rtsx_usb_ms_set_param;
        msh->caps = MEMSTICK_CAP_PAR4;

        pm_runtime_get_noresume(ms_dev(host));
        pm_runtime_set_active(ms_dev(host));
        pm_runtime_enable(ms_dev(host));

        err = memstick_add_host(msh);
        if (err)
                goto err_out;

        pm_runtime_put(ms_dev(host));

        return 0;
err_out:
        pm_runtime_disable(ms_dev(host));
        pm_runtime_put_noidle(ms_dev(host));
        memstick_free_host(msh);
        return err;
}

static void rtsx_usb_ms_drv_remove(struct platform_device *pdev)
{
        struct rtsx_usb_ms *host = platform_get_drvdata(pdev);
        struct memstick_host *msh = host->msh;
        int err;

        host->eject = true;
        msh->removing = true;
        cancel_work_sync(&host->handle_req);
        cancel_delayed_work_sync(&host->poll_card);

        mutex_lock(&host->host_mutex);
        if (host->req) {
                dev_dbg(ms_dev(host),
                        "%s: Controller removed during transfer\n",
                        dev_name(&msh->dev));
                host->req->error = -ENOMEDIUM;
                do {
                        err = memstick_next_req(msh, &host->req);
                        if (!err)
                                host->req->error = -ENOMEDIUM;
                } while (!err);
        }
        mutex_unlock(&host->host_mutex);

        /* Balance possible unbalanced usage count
         * e.g. unconditional module removal
         */
        if (pm_runtime_active(ms_dev(host)))
                pm_runtime_put(ms_dev(host));

        pm_runtime_disable(ms_dev(host));
        memstick_remove_host(msh);
        dev_dbg(ms_dev(host),
                ": Realtek USB Memstick controller has been removed\n");
        memstick_free_host(msh);
        platform_set_drvdata(pdev, NULL);
}

static struct platform_device_id rtsx_usb_ms_ids[] = {
        {
                .name = "rtsx_usb_ms",
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(platform, rtsx_usb_ms_ids);

static struct platform_driver rtsx_usb_ms_driver = {
        .probe          = rtsx_usb_ms_drv_probe,
        .remove         = rtsx_usb_ms_drv_remove,
        .id_table       = rtsx_usb_ms_ids,
        .driver         = {
                .name   = "rtsx_usb_ms",
                .pm     = &rtsx_usb_ms_pm_ops,
        },
};
module_platform_driver(rtsx_usb_ms_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Roger Tseng <rogerable@realtek.com>");
MODULE_DESCRIPTION("Realtek USB Memstick Card Host Driver");