// SPDX-License-Identifier: GPL-2.0-only
/* Driver for Realtek USB card reader
 *
 * Copyright(c) 2009-2013 Realtek Semiconductor Corp. All rights reserved.
 *
 * Author:
 *   Roger Tseng <rogerable@realtek.com>
 */
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/usb.h>
#include <linux/platform_device.h>
#include <linux/mfd/core.h>
#include <linux/rtsx_usb.h>

static int polling_pipe = 1;
module_param(polling_pipe, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(polling_pipe, "polling pipe (0: ctl, 1: bulk)");

static const struct mfd_cell rtsx_usb_cells[] = {
        [RTSX_USB_SD_CARD] = {
                .name = DRV_NAME_RTSX_USB_SDMMC,
                .pdata_size = 0,
        },
        [RTSX_USB_MS_CARD] = {
                .name = DRV_NAME_RTSX_USB_MS,
                .pdata_size = 0,
        },
};

static void rtsx_usb_sg_timed_out(struct timer_list *t)
{
        struct rtsx_ucr *ucr = timer_container_of(ucr, t, sg_timer);

        dev_dbg(&ucr->pusb_intf->dev, "%s: sg transfer timed out", __func__);
        usb_sg_cancel(&ucr->current_sg);
}

static int rtsx_usb_bulk_transfer_sglist(struct rtsx_ucr *ucr,
                unsigned int pipe, struct scatterlist *sg, int num_sg,
                unsigned int length, unsigned int *act_len, int timeout)
{
        int ret;

        dev_dbg(&ucr->pusb_intf->dev, "%s: xfer %u bytes, %d entries\n",
                        __func__, length, num_sg);
        ret = usb_sg_init(&ucr->current_sg, ucr->pusb_dev, pipe, 0,
                        sg, num_sg, length, GFP_NOIO);
        if (ret)
                return ret;

        ucr->sg_timer.expires = jiffies + msecs_to_jiffies(timeout);
        add_timer(&ucr->sg_timer);
        usb_sg_wait(&ucr->current_sg);
        if (!timer_delete_sync(&ucr->sg_timer))
                ret = -ETIMEDOUT;
        else
                ret = ucr->current_sg.status;

        if (act_len)
                *act_len = ucr->current_sg.bytes;

        return ret;
}

int rtsx_usb_transfer_data(struct rtsx_ucr *ucr, unsigned int pipe,
                              void *buf, unsigned int len, int num_sg,
                              unsigned int *act_len, int timeout)
{
        if (timeout < 600)
                timeout = 600;

        if (num_sg)
                return rtsx_usb_bulk_transfer_sglist(ucr, pipe,
                                (struct scatterlist *)buf, num_sg, len, act_len,
                                timeout);
        else
                return usb_bulk_msg(ucr->pusb_dev, pipe, buf, len, act_len,
                                timeout);
}
EXPORT_SYMBOL_GPL(rtsx_usb_transfer_data);

static inline void rtsx_usb_seq_cmd_hdr(struct rtsx_ucr *ucr,
                u16 addr, u16 len, u8 seq_type)
{
        rtsx_usb_cmd_hdr_tag(ucr);

        ucr->cmd_buf[PACKET_TYPE] = seq_type;
        ucr->cmd_buf[5] = (u8)(len >> 8);
        ucr->cmd_buf[6] = (u8)len;
        ucr->cmd_buf[8] = (u8)(addr >> 8);
        ucr->cmd_buf[9] = (u8)addr;

        if (seq_type == SEQ_WRITE)
                ucr->cmd_buf[STAGE_FLAG] = 0;
        else
                ucr->cmd_buf[STAGE_FLAG] = STAGE_R;
}

static int rtsx_usb_seq_write_register(struct rtsx_ucr *ucr,
                u16 addr, u16 len, u8 *data)
{
        u16 cmd_len = ALIGN(SEQ_WRITE_DATA_OFFSET + len, 4);

        if (!data)
                return -EINVAL;

        if (cmd_len > IOBUF_SIZE)
                return -EINVAL;

        rtsx_usb_seq_cmd_hdr(ucr, addr, len, SEQ_WRITE);
        memcpy(ucr->cmd_buf + SEQ_WRITE_DATA_OFFSET, data, len);

        return rtsx_usb_transfer_data(ucr,
                        usb_sndbulkpipe(ucr->pusb_dev, EP_BULK_OUT),
                        ucr->cmd_buf, cmd_len, 0, NULL, 100);
}

static int rtsx_usb_seq_read_register(struct rtsx_ucr *ucr,
                u16 addr, u16 len, u8 *data)
{
        int i, ret;
        u16 rsp_len = round_down(len, 4);
        u16 res_len = len - rsp_len;

        if (!data)
                return -EINVAL;

        /* 4-byte aligned part */
        if (rsp_len) {
                rtsx_usb_seq_cmd_hdr(ucr, addr, len, SEQ_READ);
                ret = rtsx_usb_transfer_data(ucr,
                                usb_sndbulkpipe(ucr->pusb_dev, EP_BULK_OUT),
                                ucr->cmd_buf, 12, 0, NULL, 100);
                if (ret)
                        return ret;

                ret = rtsx_usb_transfer_data(ucr,
                                usb_rcvbulkpipe(ucr->pusb_dev, EP_BULK_IN),
                                data, rsp_len, 0, NULL, 100);
                if (ret)
                        return ret;
        }

        /* unaligned part */
        for (i = 0; i < res_len; i++) {
                ret = rtsx_usb_read_register(ucr, addr + rsp_len + i,
                                data + rsp_len + i);
                if (ret)
                        return ret;
        }

        return 0;
}

int rtsx_usb_read_ppbuf(struct rtsx_ucr *ucr, u8 *buf, int buf_len)
{
        return rtsx_usb_seq_read_register(ucr, PPBUF_BASE2, (u16)buf_len, buf);
}
EXPORT_SYMBOL_GPL(rtsx_usb_read_ppbuf);

int rtsx_usb_write_ppbuf(struct rtsx_ucr *ucr, u8 *buf, int buf_len)
{
        return rtsx_usb_seq_write_register(ucr, PPBUF_BASE2, (u16)buf_len, buf);
}
EXPORT_SYMBOL_GPL(rtsx_usb_write_ppbuf);

int rtsx_usb_ep0_write_register(struct rtsx_ucr *ucr, u16 addr,
                u8 mask, u8 data)
{
        u16 value, index;

        addr |= EP0_WRITE_REG_CMD << EP0_OP_SHIFT;
        value = swab16(addr);
        index = mask | data << 8;

        return usb_control_msg(ucr->pusb_dev,
                        usb_sndctrlpipe(ucr->pusb_dev, 0), RTSX_USB_REQ_REG_OP,
                        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        value, index, NULL, 0, 100);
}
EXPORT_SYMBOL_GPL(rtsx_usb_ep0_write_register);

int rtsx_usb_ep0_read_register(struct rtsx_ucr *ucr, u16 addr, u8 *data)
{
        u16 value;
        u8 *buf;
        int ret;

        if (!data)
                return -EINVAL;

        buf = kzalloc(sizeof(u8), GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        addr |= EP0_READ_REG_CMD << EP0_OP_SHIFT;
        value = swab16(addr);

        ret = usb_control_msg(ucr->pusb_dev,
                        usb_rcvctrlpipe(ucr->pusb_dev, 0), RTSX_USB_REQ_REG_OP,
                        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        value, 0, buf, 1, 100);
        *data = *buf;

        kfree(buf);
        return ret;
}
EXPORT_SYMBOL_GPL(rtsx_usb_ep0_read_register);

void rtsx_usb_add_cmd(struct rtsx_ucr *ucr, u8 cmd_type, u16 reg_addr,
                u8 mask, u8 data)
{
        int i;

        if (ucr->cmd_idx < (IOBUF_SIZE - CMD_OFFSET) / 4) {
                i = CMD_OFFSET + ucr->cmd_idx * 4;

                ucr->cmd_buf[i++] = ((cmd_type & 0x03) << 6) |
                        (u8)((reg_addr >> 8) & 0x3F);
                ucr->cmd_buf[i++] = (u8)reg_addr;
                ucr->cmd_buf[i++] = mask;
                ucr->cmd_buf[i++] = data;

                ucr->cmd_idx++;
        }
}
EXPORT_SYMBOL_GPL(rtsx_usb_add_cmd);

int rtsx_usb_send_cmd(struct rtsx_ucr *ucr, u8 flag, int timeout)
{
        int ret;

        ucr->cmd_buf[CNT_H] = (u8)(ucr->cmd_idx >> 8);
        ucr->cmd_buf[CNT_L] = (u8)(ucr->cmd_idx);
        ucr->cmd_buf[STAGE_FLAG] = flag;

        ret = rtsx_usb_transfer_data(ucr,
                        usb_sndbulkpipe(ucr->pusb_dev, EP_BULK_OUT),
                        ucr->cmd_buf, ucr->cmd_idx * 4 + CMD_OFFSET,
                        0, NULL, timeout);
        if (ret) {
                rtsx_usb_clear_fsm_err(ucr);
                return ret;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(rtsx_usb_send_cmd);

int rtsx_usb_get_rsp(struct rtsx_ucr *ucr, int rsp_len, int timeout)
{
        if (rsp_len <= 0)
                return -EINVAL;

        rsp_len = ALIGN(rsp_len, 4);

        return rtsx_usb_transfer_data(ucr,
                        usb_rcvbulkpipe(ucr->pusb_dev, EP_BULK_IN),
                        ucr->rsp_buf, rsp_len, 0, NULL, timeout);
}
EXPORT_SYMBOL_GPL(rtsx_usb_get_rsp);

static int rtsx_usb_get_status_with_bulk(struct rtsx_ucr *ucr, u16 *status)
{
        int ret;

        rtsx_usb_init_cmd(ucr);
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, CARD_EXIST, 0x00, 0x00);
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, OCPSTAT, 0x00, 0x00);
        ret = rtsx_usb_send_cmd(ucr, MODE_CR, 100);
        if (ret)
                return ret;

        ret = rtsx_usb_get_rsp(ucr, 2, 100);
        if (ret)
                return ret;

        *status = ((ucr->rsp_buf[0] >> 2) & 0x0f) |
                  ((ucr->rsp_buf[1] & 0x03) << 4);

        return 0;
}

int rtsx_usb_get_card_status(struct rtsx_ucr *ucr, u16 *status)
{
        int ret;
        u16 *buf;

        if (!status)
                return -EINVAL;

        if (polling_pipe == 0) {
                buf = kzalloc(sizeof(u16), GFP_KERNEL);
                if (!buf)
                        return -ENOMEM;

                ret = usb_control_msg(ucr->pusb_dev,
                                usb_rcvctrlpipe(ucr->pusb_dev, 0),
                                RTSX_USB_REQ_POLL,
                                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                0, 0, buf, 2, 100);
                *status = *buf;

                kfree(buf);
        } else {
                ret = rtsx_usb_get_status_with_bulk(ucr, status);
        }

        /* usb_control_msg may return positive when success */
        if (ret < 0)
                return ret;

        return 0;
}
EXPORT_SYMBOL_GPL(rtsx_usb_get_card_status);

static int rtsx_usb_write_phy_register(struct rtsx_ucr *ucr, u8 addr, u8 val)
{
        dev_dbg(&ucr->pusb_intf->dev, "Write 0x%x to phy register 0x%x\n",
                        val, addr);

        rtsx_usb_init_cmd(ucr);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VSTAIN, 0xFF, val);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VCONTROL, 0xFF, addr & 0x0F);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VLOADM, 0xFF, 0x00);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VLOADM, 0xFF, 0x00);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VLOADM, 0xFF, 0x01);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VCONTROL,
                        0xFF, (addr >> 4) & 0x0F);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VLOADM, 0xFF, 0x00);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VLOADM, 0xFF, 0x00);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, HS_VLOADM, 0xFF, 0x01);

        return rtsx_usb_send_cmd(ucr, MODE_C, 100);
}

int rtsx_usb_write_register(struct rtsx_ucr *ucr, u16 addr, u8 mask, u8 data)
{
        rtsx_usb_init_cmd(ucr);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, addr, mask, data);
        return rtsx_usb_send_cmd(ucr, MODE_C, 100);
}
EXPORT_SYMBOL_GPL(rtsx_usb_write_register);

int rtsx_usb_read_register(struct rtsx_ucr *ucr, u16 addr, u8 *data)
{
        int ret;

        if (data != NULL)
                *data = 0;

        rtsx_usb_init_cmd(ucr);
        rtsx_usb_add_cmd(ucr, READ_REG_CMD, addr, 0, 0);
        ret = rtsx_usb_send_cmd(ucr, MODE_CR, 100);
        if (ret)
                return ret;

        ret = rtsx_usb_get_rsp(ucr, 1, 100);
        if (ret)
                return ret;

        if (data != NULL)
                *data = ucr->rsp_buf[0];

        return 0;
}
EXPORT_SYMBOL_GPL(rtsx_usb_read_register);

static inline u8 double_ssc_depth(u8 depth)
{
        return (depth > 1) ? (depth - 1) : depth;
}

static u8 revise_ssc_depth(u8 ssc_depth, u8 div)
{
        if (div > CLK_DIV_1) {
                if (ssc_depth > div - 1)
                        ssc_depth -= (div - 1);
                else
                        ssc_depth = SSC_DEPTH_2M;
        }

        return ssc_depth;
}

int rtsx_usb_switch_clock(struct rtsx_ucr *ucr, unsigned int card_clock,
                u8 ssc_depth, bool initial_mode, bool double_clk, bool vpclk)
{
        int ret;
        u8 n, clk_divider, mcu_cnt, div;

        if (!card_clock) {
                ucr->cur_clk = 0;
                return 0;
        }

        if (initial_mode) {
                /* We use 250k(around) here, in initial stage */
                clk_divider = SD_CLK_DIVIDE_128;
                card_clock = 30000000;
        } else {
                clk_divider = SD_CLK_DIVIDE_0;
        }

        ret = rtsx_usb_write_register(ucr, SD_CFG1,
                        SD_CLK_DIVIDE_MASK, clk_divider);
        if (ret < 0)
                return ret;

        card_clock /= 1000000;
        dev_dbg(&ucr->pusb_intf->dev,
                        "Switch card clock to %dMHz\n", card_clock);

        if (!initial_mode && double_clk)
                card_clock *= 2;
        dev_dbg(&ucr->pusb_intf->dev,
                        "Internal SSC clock: %dMHz (cur_clk = %d)\n",
                        card_clock, ucr->cur_clk);

        if (card_clock == ucr->cur_clk)
                return 0;

        /* Converting clock value into internal settings: n and div */
        n = card_clock - 2;
        if ((card_clock <= 2) || (n > MAX_DIV_N))
                return -EINVAL;

        mcu_cnt = 60/card_clock + 3;
        if (mcu_cnt > 15)
                mcu_cnt = 15;

        /* Make sure that the SSC clock div_n is not less than MIN_DIV_N */

        div = CLK_DIV_1;
        while (n < MIN_DIV_N && div < CLK_DIV_4) {
                n = (n + 2) * 2 - 2;
                div++;
        }
        dev_dbg(&ucr->pusb_intf->dev, "n = %d, div = %d\n", n, div);

        if (double_clk)
                ssc_depth = double_ssc_depth(ssc_depth);

        ssc_depth = revise_ssc_depth(ssc_depth, div);
        dev_dbg(&ucr->pusb_intf->dev, "ssc_depth = %d\n", ssc_depth);

        rtsx_usb_init_cmd(ucr);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CLK_DIV, CLK_CHANGE, CLK_CHANGE);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CLK_DIV,
                        0x3F, (div << 4) | mcu_cnt);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SSC_CTL1, SSC_RSTB, 0);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SSC_CTL2,
                        SSC_DEPTH_MASK, ssc_depth);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SSC_DIV_N_0, 0xFF, n);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SSC_CTL1, SSC_RSTB, SSC_RSTB);
        if (vpclk) {
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SD_VPCLK0_CTL,
                                PHASE_NOT_RESET, 0);
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SD_VPCLK0_CTL,
                                PHASE_NOT_RESET, PHASE_NOT_RESET);
        }

        ret = rtsx_usb_send_cmd(ucr, MODE_C, 2000);
        if (ret < 0)
                return ret;

        ret = rtsx_usb_write_register(ucr, SSC_CTL1, 0xff,
                        SSC_RSTB | SSC_8X_EN | SSC_SEL_4M);
        if (ret < 0)
                return ret;

        /* Wait SSC clock stable */
        usleep_range(100, 1000);

        ret = rtsx_usb_write_register(ucr, CLK_DIV, CLK_CHANGE, 0);
        if (ret < 0)
                return ret;

        ucr->cur_clk = card_clock;

        return 0;
}
EXPORT_SYMBOL_GPL(rtsx_usb_switch_clock);

int rtsx_usb_card_exclusive_check(struct rtsx_ucr *ucr, int card)
{
        int ret;
        u16 val;
        u16 cd_mask[] = {
                [RTSX_USB_SD_CARD] = (CD_MASK & ~SD_CD),
                [RTSX_USB_MS_CARD] = (CD_MASK & ~MS_CD)
        };

        ret = rtsx_usb_get_card_status(ucr, &val);
        /*
         * If get status fails, return 0 (ok) for the exclusive check
         * and let the flow fail at somewhere else.
         */
        if (ret)
                return 0;

        if (val & cd_mask[card])
                return -EIO;

        return 0;
}
EXPORT_SYMBOL_GPL(rtsx_usb_card_exclusive_check);

static int rtsx_usb_reset_chip(struct rtsx_ucr *ucr)
{
        int ret;
        u8 val;

        rtsx_usb_init_cmd(ucr);

        if (CHECK_PKG(ucr, LQFP48)) {
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL,
                                LDO3318_PWR_MASK, LDO_SUSPEND);
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PWR_CTL,
                                FORCE_LDO_POWERB, FORCE_LDO_POWERB);
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL1,
                                0x30, 0x10);
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL5,
                                0x03, 0x01);
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_PULL_CTL6,
                                0x0C, 0x04);
        }

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SYS_DUMMY0, NYET_MSAK, NYET_EN);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CD_DEGLITCH_WIDTH, 0xFF, 0x08);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD,
                        CD_DEGLITCH_EN, XD_CD_DEGLITCH_EN, 0x0);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, SD30_DRIVE_SEL,
                        SD30_DRIVE_MASK, DRIVER_TYPE_D);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD,
                        CARD_DRIVE_SEL, SD20_DRIVE_MASK, 0x0);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, LDO_POWER_CFG, 0xE0, 0x0);

        if (ucr->is_rts5179)
                rtsx_usb_add_cmd(ucr, WRITE_REG_CMD,
                                CARD_PULL_CTL5, 0x03, 0x01);

        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_DMA1_CTL,
                       EXTEND_DMA1_ASYNC_SIGNAL, EXTEND_DMA1_ASYNC_SIGNAL);
        rtsx_usb_add_cmd(ucr, WRITE_REG_CMD, CARD_INT_PEND,
                        XD_INT | MS_INT | SD_INT,
                        XD_INT | MS_INT | SD_INT);

        ret = rtsx_usb_send_cmd(ucr, MODE_C, 100);
        if (ret)
                return ret;
        /* config OCP */
        rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_DETECT_EN, MS_OCP_DETECT_EN);
        rtsx_usb_write_register(ucr, OCPPARA1, 0xF0, 0x50);
        rtsx_usb_write_register(ucr, OCPPARA2, 0x7, 0x3);

        /* config non-crystal mode */
        rtsx_usb_read_register(ucr, CFG_MODE, &val);
        if ((val & XTAL_FREE) || ((val & CLK_MODE_MASK) == CLK_MODE_NON_XTAL)) {
                ret = rtsx_usb_write_phy_register(ucr, 0xC2, 0x7C);
                if (ret)
                        return ret;
        }

        return 0;
}

static int rtsx_usb_init_chip(struct rtsx_ucr *ucr)
{
        int ret;
        u8 val;

        rtsx_usb_clear_fsm_err(ucr);

        /* power on SSC */
        ret = rtsx_usb_write_register(ucr,
                        FPDCTL, SSC_POWER_MASK, SSC_POWER_ON);
        if (ret)
                return ret;

        usleep_range(100, 1000);
        ret = rtsx_usb_write_register(ucr, CLK_DIV, CLK_CHANGE, 0x00);
        if (ret)
                return ret;

        /* determine IC version */
        ret = rtsx_usb_read_register(ucr, HW_VERSION, &val);
        if (ret)
                return ret;

        ucr->ic_version = val & HW_VER_MASK;

        /* determine package */
        ret = rtsx_usb_read_register(ucr, CARD_SHARE_MODE, &val);
        if (ret)
                return ret;

        if (val & CARD_SHARE_LQFP_SEL) {
                ucr->package = LQFP48;
                dev_dbg(&ucr->pusb_intf->dev, "Package: LQFP48\n");
        } else {
                ucr->package = QFN24;
                dev_dbg(&ucr->pusb_intf->dev, "Package: QFN24\n");
        }

        /* determine IC variations */
        rtsx_usb_read_register(ucr, CFG_MODE_1, &val);
        if (val & RTS5179) {
                ucr->is_rts5179 = true;
                dev_dbg(&ucr->pusb_intf->dev, "Device is rts5179\n");
        } else {
                ucr->is_rts5179 = false;
        }

        return rtsx_usb_reset_chip(ucr);
}

static int rtsx_usb_probe(struct usb_interface *intf,
                         const struct usb_device_id *id)
{
        struct usb_device *usb_dev = interface_to_usbdev(intf);
        struct rtsx_ucr *ucr;
        int ret;

        dev_dbg(&intf->dev,
                ": Realtek USB Card Reader found at bus %03d address %03d\n",
                 usb_dev->bus->busnum, usb_dev->devnum);

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

        ucr->pusb_dev = usb_dev;

        ucr->cmd_buf = kmalloc(IOBUF_SIZE, GFP_KERNEL);
        if (!ucr->cmd_buf)
                return -ENOMEM;

        ucr->rsp_buf = kmalloc(IOBUF_SIZE, GFP_KERNEL);
        if (!ucr->rsp_buf) {
                ret = -ENOMEM;
                goto out_free_cmd_buf;
        }

        usb_set_intfdata(intf, ucr);

        ucr->vendor_id = id->idVendor;
        ucr->product_id = id->idProduct;

        mutex_init(&ucr->dev_mutex);

        ucr->pusb_intf = intf;

        /* initialize */
        ret = rtsx_usb_init_chip(ucr);
        if (ret)
                goto out_init_fail;

        /* initialize USB SG transfer timer */
        timer_setup(&ucr->sg_timer, rtsx_usb_sg_timed_out, 0);

        ret = mfd_add_hotplug_devices(&intf->dev, rtsx_usb_cells,
                                      ARRAY_SIZE(rtsx_usb_cells));
        if (ret)
                goto out_init_fail;

#ifdef CONFIG_PM
        intf->needs_remote_wakeup = 1;
        usb_enable_autosuspend(usb_dev);
#endif

        return 0;

out_init_fail:
        usb_set_intfdata(ucr->pusb_intf, NULL);
        kfree(ucr->rsp_buf);
        ucr->rsp_buf = NULL;
out_free_cmd_buf:
        kfree(ucr->cmd_buf);
        ucr->cmd_buf = NULL;
        return ret;
}

static void rtsx_usb_disconnect(struct usb_interface *intf)
{
        struct rtsx_ucr *ucr = (struct rtsx_ucr *)usb_get_intfdata(intf);

        dev_dbg(&intf->dev, "%s called\n", __func__);

        mfd_remove_devices(&intf->dev);

        usb_set_intfdata(ucr->pusb_intf, NULL);

        kfree(ucr->cmd_buf);
        ucr->cmd_buf = NULL;

        kfree(ucr->rsp_buf);
        ucr->rsp_buf = NULL;
}

#ifdef CONFIG_PM
static int rtsx_usb_resume_child(struct device *dev, void *data)
{
        pm_request_resume(dev);
        return 0;
}

static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message)
{
        struct rtsx_ucr *ucr =
                (struct rtsx_ucr *)usb_get_intfdata(intf);
        u16 val = 0;

        dev_dbg(&intf->dev, "%s called with pm message 0x%04x\n",
                        __func__, message.event);

        if (PMSG_IS_AUTO(message)) {
                if (mutex_trylock(&ucr->dev_mutex)) {
                        rtsx_usb_get_card_status(ucr, &val);
                        mutex_unlock(&ucr->dev_mutex);

                        /* Defer the autosuspend if card exists */
                        if (val & (SD_CD | MS_CD)) {
                                device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child);
                                return -EAGAIN;
                        } else {
                                /* if the card does not exists, clear OCP status */
                                rtsx_usb_write_register(ucr, OCPCTL, MS_OCP_CLEAR, MS_OCP_CLEAR);
                        }
                } else {
                        /* There is an ongoing operation*/
                        return -EAGAIN;
                }
        }

        return 0;
}

static int rtsx_usb_resume(struct usb_interface *intf)
{
        device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child);
        return 0;
}

static int rtsx_usb_reset_resume(struct usb_interface *intf)
{
        struct rtsx_ucr *ucr =
                (struct rtsx_ucr *)usb_get_intfdata(intf);

        rtsx_usb_reset_chip(ucr);
        device_for_each_child(&intf->dev, NULL, rtsx_usb_resume_child);
        return 0;
}

#else /* CONFIG_PM */

#define rtsx_usb_suspend NULL
#define rtsx_usb_resume NULL
#define rtsx_usb_reset_resume NULL

#endif /* CONFIG_PM */


static int rtsx_usb_pre_reset(struct usb_interface *intf)
{
        struct rtsx_ucr *ucr = (struct rtsx_ucr *)usb_get_intfdata(intf);

        mutex_lock(&ucr->dev_mutex);
        return 0;
}

static int rtsx_usb_post_reset(struct usb_interface *intf)
{
        struct rtsx_ucr *ucr = (struct rtsx_ucr *)usb_get_intfdata(intf);

        mutex_unlock(&ucr->dev_mutex);
        return 0;
}

static const struct usb_device_id rtsx_usb_usb_ids[] = {
        { USB_DEVICE(0x0BDA, 0x0129) },
        { USB_DEVICE(0x0BDA, 0x0139) },
        { USB_DEVICE(0x0BDA, 0x0140) },
        { }
};
MODULE_DEVICE_TABLE(usb, rtsx_usb_usb_ids);

static struct usb_driver rtsx_usb_driver = {
        .name                   = DRV_NAME_RTSX_USB,
        .probe                  = rtsx_usb_probe,
        .disconnect             = rtsx_usb_disconnect,
        .suspend                = rtsx_usb_suspend,
        .resume                 = rtsx_usb_resume,
        .reset_resume           = rtsx_usb_reset_resume,
        .pre_reset              = rtsx_usb_pre_reset,
        .post_reset             = rtsx_usb_post_reset,
        .id_table               = rtsx_usb_usb_ids,
        .supports_autosuspend   = 1,
        .soft_unbind            = 1,
};

module_usb_driver(rtsx_usb_driver);

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