/*
 * Driver for Realtek RTS51xx USB card reader
 *
 * Copyright(c) 2009 Realtek Semiconductor Corp. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 * Author:
 *   wwang (wei_wang@realsil.com.cn)
 *   No. 450, Shenhu Road, Suzhou Industry Park, Suzhou, China
 */

#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/kernel.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <linux/cdrom.h>

#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/usb_usual.h>

#include "usb.h"
#include "transport.h"
#include "protocol.h"
#include "debug.h"
#include "scsiglue.h"

#define DRV_NAME "ums-realtek"

MODULE_DESCRIPTION("Driver for Realtek USB Card Reader");
MODULE_AUTHOR("wwang <wei_wang@realsil.com.cn>");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.03");

static int auto_delink_en = 1;
module_param(auto_delink_en, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(auto_delink_en, "auto delink mode (0=firmware, 1=software [default])");

#ifdef CONFIG_REALTEK_AUTOPM
static int ss_en = 1;
module_param(ss_en, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ss_en, "enable selective suspend");

static int ss_delay = 50;
module_param(ss_delay, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ss_delay,
		 "seconds to delay before entering selective suspend");

enum RTS51X_STAT {
	RTS51X_STAT_INIT,
	RTS51X_STAT_IDLE,
	RTS51X_STAT_RUN,
	RTS51X_STAT_SS
};

#define POLLING_INTERVAL	50

#define rts51x_set_stat(chip, stat)	\
	((chip)->state = (enum RTS51X_STAT)(stat))
#define rts51x_get_stat(chip)		((chip)->state)

#define SET_LUN_READY(chip, lun)	((chip)->lun_ready |= ((u8)1 << (lun)))
#define CLR_LUN_READY(chip, lun)	((chip)->lun_ready &= ~((u8)1 << (lun)))
#define TST_LUN_READY(chip, lun)	((chip)->lun_ready & ((u8)1 << (lun)))

#endif

struct rts51x_status {
	u16 vid;
	u16 pid;
	u8 cur_lun;
	u8 card_type;
	u8 total_lun;
	u16 fw_ver;
	u8 phy_exist;
	u8 multi_flag;
	u8 multi_card;
	u8 log_exist;
	union {
		u8 detailed_type1;
		u8 detailed_type2;
	} detailed_type;
	u8 function[2];
};

struct rts51x_chip {
	u16 vendor_id;
	u16 product_id;
	char max_lun;

	struct rts51x_status *status;
	int status_len;

	u32 flag;
	struct us_data *us;

#ifdef CONFIG_REALTEK_AUTOPM
	struct timer_list rts51x_suspend_timer;
	unsigned long timer_expires;
	int pwr_state;
	u8 lun_ready;
	enum RTS51X_STAT state;
	int support_auto_delink;
#endif
	/* used to back up the protocol chosen in probe1 phase */
	proto_cmnd proto_handler_backup;
};

/* flag definition */
#define FLIDX_AUTO_DELINK		0x01

#define SCSI_LUN(srb)			((srb)->device->lun)

/* Bit Operation */
#define SET_BIT(data, idx)		((data) |= 1 << (idx))
#define CLR_BIT(data, idx)		((data) &= ~(1 << (idx)))
#define CHK_BIT(data, idx)		((data) & (1 << (idx)))

#define SET_AUTO_DELINK(chip)		((chip)->flag |= FLIDX_AUTO_DELINK)
#define CLR_AUTO_DELINK(chip)		((chip)->flag &= ~FLIDX_AUTO_DELINK)
#define CHK_AUTO_DELINK(chip)		((chip)->flag & FLIDX_AUTO_DELINK)

#define RTS51X_GET_VID(chip)		((chip)->vendor_id)
#define RTS51X_GET_PID(chip)		((chip)->product_id)

#define VENDOR_ID(chip)			((chip)->status[0].vid)
#define PRODUCT_ID(chip)		((chip)->status[0].pid)
#define FW_VERSION(chip)		((chip)->status[0].fw_ver)
#define STATUS_LEN(chip)		((chip)->status_len)

#define STATUS_SUCCESS		0
#define STATUS_FAIL		1

/* Check card reader function */
#define SUPPORT_DETAILED_TYPE1(chip)	\
		CHK_BIT((chip)->status[0].function[0], 1)
#define SUPPORT_OT(chip)		\
		CHK_BIT((chip)->status[0].function[0], 2)
#define SUPPORT_OC(chip)		\
		CHK_BIT((chip)->status[0].function[0], 3)
#define SUPPORT_AUTO_DELINK(chip)	\
		CHK_BIT((chip)->status[0].function[0], 4)
#define SUPPORT_SDIO(chip)		\
		CHK_BIT((chip)->status[0].function[1], 0)
#define SUPPORT_DETAILED_TYPE2(chip)	\
		CHK_BIT((chip)->status[0].function[1], 1)

#define CHECK_PID(chip, pid)		(RTS51X_GET_PID(chip) == (pid))
#define CHECK_FW_VER(chip, fw_ver)	(FW_VERSION(chip) == (fw_ver))
#define CHECK_ID(chip, pid, fw_ver)	\
		(CHECK_PID((chip), (pid)) && CHECK_FW_VER((chip), (fw_ver)))

static int init_realtek_cr(struct us_data *us);

/*
 * The table of devices
 */
#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
		    vendorName, productName, useProtocol, useTransport, \
		    initFunction, flags) \
{\
	USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
	.driver_info = (flags) \
}

static const struct usb_device_id realtek_cr_ids[] = {
#	include "unusual_realtek.h"
	{}			/* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, realtek_cr_ids);

#undef UNUSUAL_DEV

/*
 * The flags table
 */
#define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
		    vendor_name, product_name, use_protocol, use_transport, \
		    init_function, Flags) \
{ \
	.vendorName = vendor_name,	\
	.productName = product_name,	\
	.useProtocol = use_protocol,	\
	.useTransport = use_transport,	\
	.initFunction = init_function,	\
}

static struct us_unusual_dev realtek_cr_unusual_dev_list[] = {
#	include "unusual_realtek.h"
	{}			/* Terminating entry */
};

#undef UNUSUAL_DEV

static int rts51x_bulk_transport(struct us_data *us, u8 lun,
				 u8 *cmd, int cmd_len, u8 *buf, int buf_len,
				 enum dma_data_direction dir, int *act_len)
{
	struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *)us->iobuf;
	struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *)us->iobuf;
	int result;
	unsigned int residue;
	unsigned int cswlen;
	unsigned int cbwlen = US_BULK_CB_WRAP_LEN;

	/* set up the command wrapper */
	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
	bcb->DataTransferLength = cpu_to_le32(buf_len);
	bcb->Flags = (dir == DMA_FROM_DEVICE) ? US_BULK_FLAG_IN : 0;
	bcb->Tag = ++us->tag;
	bcb->Lun = lun;
	bcb->Length = cmd_len;

	/* copy the command payload */
	memset(bcb->CDB, 0, sizeof(bcb->CDB));
	memcpy(bcb->CDB, cmd, bcb->Length);

	/* send it to out endpoint */
	result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
					    bcb, cbwlen, NULL);
	if (result != USB_STOR_XFER_GOOD)
		return USB_STOR_TRANSPORT_ERROR;

	/* DATA STAGE */
	/* send/receive data payload, if there is any */

	if (buf && buf_len) {
		unsigned int pipe = (dir == DMA_FROM_DEVICE) ?
		    us->recv_bulk_pipe : us->send_bulk_pipe;
		result = usb_stor_bulk_transfer_buf(us, pipe,
						    buf, buf_len, NULL);
		if (result == USB_STOR_XFER_ERROR)
			return USB_STOR_TRANSPORT_ERROR;
	}

	/* get CSW for device status */
	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
					    bcs, US_BULK_CS_WRAP_LEN, &cswlen);
	if (result != USB_STOR_XFER_GOOD)
		return USB_STOR_TRANSPORT_ERROR;

	/* check bulk status */
	if (bcs->Signature != cpu_to_le32(US_BULK_CS_SIGN)) {
		usb_stor_dbg(us, "Signature mismatch: got %08X, expecting %08X\n",
			     le32_to_cpu(bcs->Signature), US_BULK_CS_SIGN);
		return USB_STOR_TRANSPORT_ERROR;
	}

	residue = bcs->Residue;
	if (bcs->Tag != us->tag)
		return USB_STOR_TRANSPORT_ERROR;

	/*
	 * try to compute the actual residue, based on how much data
	 * was really transferred and what the device tells us
	 */
	if (residue)
		residue = residue < buf_len ? residue : buf_len;

	if (act_len)
		*act_len = buf_len - residue;

	/* based on the status code, we report good or bad */
	switch (bcs->Status) {
	case US_BULK_STAT_OK:
		/* command good -- note that data could be short */
		return USB_STOR_TRANSPORT_GOOD;

	case US_BULK_STAT_FAIL:
		/* command failed */
		return USB_STOR_TRANSPORT_FAILED;

	case US_BULK_STAT_PHASE:
		/*
		 * phase error -- note that a transport reset will be
		 * invoked by the invoke_transport() function
		 */
		return USB_STOR_TRANSPORT_ERROR;
	}

	/* we should never get here, but if we do, we're in trouble */
	return USB_STOR_TRANSPORT_ERROR;
}

static int rts51x_bulk_transport_special(struct us_data *us, u8 lun,
				 u8 *cmd, int cmd_len, u8 *buf, int buf_len,
				 enum dma_data_direction dir, int *act_len)
{
	struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
	struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
	int result;
	unsigned int cswlen;
	unsigned int cbwlen = US_BULK_CB_WRAP_LEN;

	/* set up the command wrapper */
	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
	bcb->DataTransferLength = cpu_to_le32(buf_len);
	bcb->Flags = (dir == DMA_FROM_DEVICE) ? US_BULK_FLAG_IN : 0;
	bcb->Tag = ++us->tag;
	bcb->Lun = lun;
	bcb->Length = cmd_len;

	/* copy the command payload */
	memset(bcb->CDB, 0, sizeof(bcb->CDB));
	memcpy(bcb->CDB, cmd, bcb->Length);

	/* send it to out endpoint */
	result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
				bcb, cbwlen, NULL);
	if (result != USB_STOR_XFER_GOOD)
		return USB_STOR_TRANSPORT_ERROR;

	/* DATA STAGE */
	/* send/receive data payload, if there is any */

	if (buf && buf_len) {
		unsigned int pipe = (dir == DMA_FROM_DEVICE) ?
				us->recv_bulk_pipe : us->send_bulk_pipe;
		result = usb_stor_bulk_transfer_buf(us, pipe,
				buf, buf_len, NULL);
		if (result == USB_STOR_XFER_ERROR)
			return USB_STOR_TRANSPORT_ERROR;
	}

	/* get CSW for device status */
	result = usb_bulk_msg(us->pusb_dev, us->recv_bulk_pipe, bcs,
			US_BULK_CS_WRAP_LEN, &cswlen, 250);
	return result;
}

/* Determine what the maximum LUN supported is */
static int rts51x_get_max_lun(struct us_data *us)
{
	int result;

	/* issue the command */
	us->iobuf[0] = 0;
	result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
				      US_BULK_GET_MAX_LUN,
				      USB_DIR_IN | USB_TYPE_CLASS |
				      USB_RECIP_INTERFACE,
				      0, us->ifnum, us->iobuf, 1, 10 * HZ);

	usb_stor_dbg(us, "GetMaxLUN command result is %d, data is %d\n",
		     result, us->iobuf[0]);

	/* if we have a successful request, return the result */
	if (result > 0)
		return us->iobuf[0];

	return 0;
}

static int rts51x_read_mem(struct us_data *us, u16 addr, u8 *data, u16 len)
{
	int retval;
	u8 cmnd[12] = { 0 };
	u8 *buf;

	buf = kmalloc(len, GFP_NOIO);
	if (buf == NULL)
		return USB_STOR_TRANSPORT_ERROR;

	usb_stor_dbg(us, "addr = 0x%x, len = %d\n", addr, len);

	cmnd[0] = 0xF0;
	cmnd[1] = 0x0D;
	cmnd[2] = (u8) (addr >> 8);
	cmnd[3] = (u8) addr;
	cmnd[4] = (u8) (len >> 8);
	cmnd[5] = (u8) len;

	retval = rts51x_bulk_transport(us, 0, cmnd, 12,
				       buf, len, DMA_FROM_DEVICE, NULL);
	if (retval != USB_STOR_TRANSPORT_GOOD) {
		kfree(buf);
		return -EIO;
	}

	memcpy(data, buf, len);
	kfree(buf);
	return 0;
}

static int rts51x_write_mem(struct us_data *us, u16 addr, u8 *data, u16 len)
{
	int retval;
	u8 cmnd[12] = { 0 };
	u8 *buf;

	buf = kmemdup(data, len, GFP_NOIO);
	if (buf == NULL)
		return USB_STOR_TRANSPORT_ERROR;

	usb_stor_dbg(us, "addr = 0x%x, len = %d\n", addr, len);

	cmnd[0] = 0xF0;
	cmnd[1] = 0x0E;
	cmnd[2] = (u8) (addr >> 8);
	cmnd[3] = (u8) addr;
	cmnd[4] = (u8) (len >> 8);
	cmnd[5] = (u8) len;

	retval = rts51x_bulk_transport(us, 0, cmnd, 12,
				       buf, len, DMA_TO_DEVICE, NULL);
	kfree(buf);
	if (retval != USB_STOR_TRANSPORT_GOOD)
		return -EIO;

	return 0;
}

static int rts51x_read_status(struct us_data *us,
			      u8 lun, u8 *status, int len, int *actlen)
{
	int retval;
	u8 cmnd[12] = { 0 };
	u8 *buf;

	buf = kmalloc(len, GFP_NOIO);
	if (buf == NULL)
		return USB_STOR_TRANSPORT_ERROR;

	usb_stor_dbg(us, "lun = %d\n", lun);

	cmnd[0] = 0xF0;
	cmnd[1] = 0x09;

	retval = rts51x_bulk_transport(us, lun, cmnd, 12,
				       buf, len, DMA_FROM_DEVICE, actlen);
	if (retval != USB_STOR_TRANSPORT_GOOD) {
		kfree(buf);
		return -EIO;
	}

	memcpy(status, buf, len);
	kfree(buf);
	return 0;
}

static int rts51x_check_status(struct us_data *us, u8 lun)
{
	struct rts51x_chip *chip = (struct rts51x_chip *)(us->extra);
	int retval;
	u8 buf[16];

	retval = rts51x_read_status(us, lun, buf, 16, &(chip->status_len));
	if (retval != STATUS_SUCCESS)
		return -EIO;

	usb_stor_dbg(us, "chip->status_len = %d\n", chip->status_len);

	chip->status[lun].vid = ((u16) buf[0] << 8) | buf[1];
	chip->status[lun].pid = ((u16) buf[2] << 8) | buf[3];
	chip->status[lun].cur_lun = buf[4];
	chip->status[lun].card_type = buf[5];
	chip->status[lun].total_lun = buf[6];
	chip->status[lun].fw_ver = ((u16) buf[7] << 8) | buf[8];
	chip->status[lun].phy_exist = buf[9];
	chip->status[lun].multi_flag = buf[10];
	chip->status[lun].multi_card = buf[11];
	chip->status[lun].log_exist = buf[12];
	if (chip->status_len == 16) {
		chip->status[lun].detailed_type.detailed_type1 = buf[13];
		chip->status[lun].function[0] = buf[14];
		chip->status[lun].function[1] = buf[15];
	}

	return 0;
}

static int enable_oscillator(struct us_data *us)
{
	int retval;
	u8 value;

	retval = rts51x_read_mem(us, 0xFE77, &value, 1);
	if (retval < 0)
		return -EIO;

	value |= 0x04;
	retval = rts51x_write_mem(us, 0xFE77, &value, 1);
	if (retval < 0)
		return -EIO;

	retval = rts51x_read_mem(us, 0xFE77, &value, 1);
	if (retval < 0)
		return -EIO;

	if (!(value & 0x04))
		return -EIO;

	return 0;
}

static int __do_config_autodelink(struct us_data *us, u8 *data, u16 len)
{
	int retval;
	u8 cmnd[12] = {0};
	u8 *buf;

	usb_stor_dbg(us, "addr = 0xfe47, len = %d\n", len);

	buf = kmemdup(data, len, GFP_NOIO);
	if (!buf)
		return USB_STOR_TRANSPORT_ERROR;

	cmnd[0] = 0xF0;
	cmnd[1] = 0x0E;
	cmnd[2] = 0xfe;
	cmnd[3] = 0x47;
	cmnd[4] = (u8)(len >> 8);
	cmnd[5] = (u8)len;

	retval = rts51x_bulk_transport_special(us, 0, cmnd, 12, buf, len, DMA_TO_DEVICE, NULL);
	kfree(buf);
	if (retval != USB_STOR_TRANSPORT_GOOD) {
		return -EIO;
	}

	return 0;
}

static int do_config_autodelink(struct us_data *us, int enable, int force)
{
	int retval;
	u8 value;

	retval = rts51x_read_mem(us, 0xFE47, &value, 1);
	if (retval < 0)
		return -EIO;

	if (enable) {
		if (force)
			value |= 0x03;
		else
			value |= 0x01;
	} else {
		value &= ~0x03;
	}

	usb_stor_dbg(us, "set 0xfe47 to 0x%x\n", value);

	/* retval = rts51x_write_mem(us, 0xFE47, &value, 1); */
	retval = __do_config_autodelink(us, &value, 1);
	if (retval < 0)
		return -EIO;

	return 0;
}

static int config_autodelink_after_power_on(struct us_data *us)
{
	struct rts51x_chip *chip = (struct rts51x_chip *)(us->extra);
	int retval;
	u8 value;

	if (!CHK_AUTO_DELINK(chip))
		return 0;

	retval = rts51x_read_mem(us, 0xFE47, &value, 1);
	if (retval < 0)
		return -EIO;

	if (auto_delink_en) {
		CLR_BIT(value, 0);
		CLR_BIT(value, 1);
		SET_BIT(value, 2);

		if (CHECK_ID(chip, 0x0138, 0x3882))
			CLR_BIT(value, 2);

		SET_BIT(value, 7);

		/* retval = rts51x_write_mem(us, 0xFE47, &value, 1); */
		retval = __do_config_autodelink(us, &value, 1);
		if (retval < 0)
			return -EIO;

		retval = enable_oscillator(us);
		if (retval == 0)
			(void)do_config_autodelink(us, 1, 0);
	} else {
		/* Autodelink controlled by firmware */

		SET_BIT(value, 2);

		if (CHECK_ID(chip, 0x0138, 0x3882))
			CLR_BIT(value, 2);

		if (CHECK_ID(chip, 0x0159, 0x5889) ||
		    CHECK_ID(chip, 0x0138, 0x3880)) {
			CLR_BIT(value, 0);
			CLR_BIT(value, 7);
		}

		/* retval = rts51x_write_mem(us, 0xFE47, &value, 1); */
		retval = __do_config_autodelink(us, &value, 1);
		if (retval < 0)
			return -EIO;

		if (CHECK_ID(chip, 0x0159, 0x5888)) {
			value = 0xFF;
			retval = rts51x_write_mem(us, 0xFE79, &value, 1);
			if (retval < 0)
				return -EIO;

			value = 0x01;
			retval = rts51x_write_mem(us, 0x48, &value, 1);
			if (retval < 0)
				return -EIO;
		}
	}

	return 0;
}

#ifdef CONFIG_PM
static int config_autodelink_before_power_down(struct us_data *us)
{
	struct rts51x_chip *chip = (struct rts51x_chip *)(us->extra);
	int retval;
	u8 value;

	if (!CHK_AUTO_DELINK(chip))
		return 0;

	if (auto_delink_en) {
		retval = rts51x_read_mem(us, 0xFE77, &value, 1);
		if (retval < 0)
			return -EIO;

		SET_BIT(value, 2);
		retval = rts51x_write_mem(us, 0xFE77, &value, 1);
		if (retval < 0)
			return -EIO;

		if (CHECK_ID(chip, 0x0159, 0x5888)) {
			value = 0x01;
			retval = rts51x_write_mem(us, 0x48, &value, 1);
			if (retval < 0)
				return -EIO;
		}

		retval = rts51x_read_mem(us, 0xFE47, &value, 1);
		if (retval < 0)
			return -EIO;

		SET_BIT(value, 0);
		if (CHECK_ID(chip, 0x0138, 0x3882))
			SET_BIT(value, 2);
		retval = rts51x_write_mem(us, 0xFE77, &value, 1);
		if (retval < 0)
			return -EIO;
	} else {
		if (CHECK_ID(chip, 0x0159, 0x5889) ||
		    CHECK_ID(chip, 0x0138, 0x3880) ||
		    CHECK_ID(chip, 0x0138, 0x3882)) {
			retval = rts51x_read_mem(us, 0xFE47, &value, 1);
			if (retval < 0)
				return -EIO;

			if (CHECK_ID(chip, 0x0159, 0x5889) ||
			    CHECK_ID(chip, 0x0138, 0x3880)) {
				SET_BIT(value, 0);
				SET_BIT(value, 7);
			}

			if (CHECK_ID(chip, 0x0138, 0x3882))
				SET_BIT(value, 2);

			/* retval = rts51x_write_mem(us, 0xFE47, &value, 1); */
			retval = __do_config_autodelink(us, &value, 1);
			if (retval < 0)
				return -EIO;
		}

		if (CHECK_ID(chip, 0x0159, 0x5888)) {
			value = 0x01;
			retval = rts51x_write_mem(us, 0x48, &value, 1);
			if (retval < 0)
				return -EIO;
		}
	}

	return 0;
}

static void fw5895_init(struct us_data *us)
{
	struct rts51x_chip *chip = (struct rts51x_chip *)(us->extra);
	int retval;
	u8 val;

	if ((PRODUCT_ID(chip) != 0x0158) || (FW_VERSION(chip) != 0x5895)) {
		usb_stor_dbg(us, "Not the specified device, return immediately!\n");
	} else {
		retval = rts51x_read_mem(us, 0xFD6F, &val, 1);
		if (retval == STATUS_SUCCESS && (val & 0x1F) == 0) {
			val = 0x1F;
			retval = rts51x_write_mem(us, 0xFD70, &val, 1);
			if (retval != STATUS_SUCCESS)
				usb_stor_dbg(us, "Write memory fail\n");
		} else {
			usb_stor_dbg(us, "Read memory fail, OR (val & 0x1F) != 0\n");
		}
	}
}
#endif

#ifdef CONFIG_REALTEK_AUTOPM
static void fw5895_set_mmc_wp(struct us_data *us)
{
	struct rts51x_chip *chip = (struct rts51x_chip *)(us->extra);
	int retval;
	u8 buf[13];

	if ((PRODUCT_ID(chip) != 0x0158) || (FW_VERSION(chip) != 0x5895)) {
		usb_stor_dbg(us, "Not the specified device, return immediately!\n");
	} else {
		retval = rts51x_read_mem(us, 0xFD6F, buf, 1);
		if (retval == STATUS_SUCCESS && (buf[0] & 0x24) == 0x24) {
			/* SD Exist and SD WP */
			retval = rts51x_read_mem(us, 0xD04E, buf, 1);
			if (retval == STATUS_SUCCESS) {
				buf[0] |= 0x04;
				retval = rts51x_write_mem(us, 0xFD70, buf, 1);
				if (retval != STATUS_SUCCESS)
					usb_stor_dbg(us, "Write memory fail\n");
			} else {
				usb_stor_dbg(us, "Read memory fail\n");
			}
		} else {
			usb_stor_dbg(us, "Read memory fail, OR (buf[0]&0x24)!=0x24\n");
		}
	}
}

static void rts51x_modi_suspend_timer(struct rts51x_chip *chip)
{
	struct us_data *us = chip->us;

	usb_stor_dbg(us, "state:%d\n", rts51x_get_stat(chip));

	chip->timer_expires = jiffies + msecs_to_jiffies(1000*ss_delay);
	mod_timer(&chip->rts51x_suspend_timer, chip->timer_expires);
}

static void rts51x_suspend_timer_fn(unsigned long data)
{
	struct rts51x_chip *chip = (struct rts51x_chip *)data;
	struct us_data *us = chip->us;

	switch (rts51x_get_stat(chip)) {
	case RTS51X_STAT_INIT:
	case RTS51X_STAT_RUN:
		rts51x_modi_suspend_timer(chip);
		break;
	case RTS51X_STAT_IDLE:
	case RTS51X_STAT_SS:
		usb_stor_dbg(us, "RTS51X_STAT_SS, power.usage:%d\n",
			     atomic_read(&us->pusb_intf->dev.power.usage_count));

		if (atomic_read(&us->pusb_intf->dev.power.usage_count) > 0) {
			usb_stor_dbg(us, "Ready to enter SS state\n");
			rts51x_set_stat(chip, RTS51X_STAT_SS);
			/* ignore mass storage interface's children */
			pm_suspend_ignore_children(&us->pusb_intf->dev, true);
			usb_autopm_put_interface_async(us->pusb_intf);
			usb_stor_dbg(us, "RTS51X_STAT_SS 01, power.usage:%d\n",
				     atomic_read(&us->pusb_intf->dev.power.usage_count));
		}
		break;
	default:
		usb_stor_dbg(us, "Unknown state !!!\n");
		break;
	}
}

static inline int working_scsi(struct scsi_cmnd *srb)
{
	if ((srb->cmnd[0] == TEST_UNIT_READY) ||
	    (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL)) {
		return 0;
	}

	return 1;
}

static void rts51x_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
{
	struct rts51x_chip *chip = (struct rts51x_chip *)(us->extra);
	static int card_first_show = 1;
	static u8 media_not_present[] = { 0x70, 0, 0x02, 0, 0, 0, 0,
		10, 0, 0, 0, 0, 0x3A, 0, 0, 0, 0, 0
	};
	static u8 invalid_cmd_field[] = { 0x70, 0, 0x05, 0, 0, 0, 0,
		10, 0, 0, 0, 0, 0x24, 0, 0, 0, 0, 0
	};
	int ret;

	if (working_scsi(srb)) {
		usb_stor_dbg(us, "working scsi, power.usage:%d\n",
			     atomic_read(&us->pusb_intf->dev.power.usage_count));

		if (atomic_read(&us->pusb_intf->dev.power.usage_count) <= 0) {
			ret = usb_autopm_get_interface(us->pusb_intf);
			usb_stor_dbg(us, "working scsi, ret=%d\n", ret);
		}
		if (rts51x_get_stat(chip) != RTS51X_STAT_RUN)
			rts51x_set_stat(chip, RTS51X_STAT_RUN);
		chip->proto_handler_backup(srb, us);
	} else {
		if (rts51x_get_stat(chip) == RTS51X_STAT_SS) {
			usb_stor_dbg(us, "NOT working scsi\n");
			if ((srb->cmnd[0] == TEST_UNIT_READY) &&
			    (chip->pwr_state == US_SUSPEND)) {
				if (TST_LUN_READY(chip, srb->device->lun)) {
					srb->result = SAM_STAT_GOOD;
				} else {
					srb->result = SAM_STAT_CHECK_CONDITION;
					memcpy(srb->sense_buffer,
					       media_not_present,
					       US_SENSE_SIZE);
				}
				usb_stor_dbg(us, "TEST_UNIT_READY\n");
				goto out;
			}
			if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
				int prevent = srb->cmnd[4] & 0x1;
				if (prevent) {
					srb->result = SAM_STAT_CHECK_CONDITION;
					memcpy(srb->sense_buffer,
					       invalid_cmd_field,
					       US_SENSE_SIZE);
				} else {
					srb->result = SAM_STAT_GOOD;
				}
				usb_stor_dbg(us, "ALLOW_MEDIUM_REMOVAL\n");
				goto out;
			}
		} else {
			usb_stor_dbg(us, "NOT working scsi, not SS\n");
			chip->proto_handler_backup(srb, us);
			/* Check whether card is plugged in */
			if (srb->cmnd[0] == TEST_UNIT_READY) {
				if (srb->result == SAM_STAT_GOOD) {
					SET_LUN_READY(chip, srb->device->lun);
					if (card_first_show) {
						card_first_show = 0;
						fw5895_set_mmc_wp(us);
					}
				} else {
					CLR_LUN_READY(chip, srb->device->lun);
					card_first_show = 1;
				}
			}
			if (rts51x_get_stat(chip) != RTS51X_STAT_IDLE)
				rts51x_set_stat(chip, RTS51X_STAT_IDLE);
		}
	}
out:
	usb_stor_dbg(us, "state:%d\n", rts51x_get_stat(chip));
	if (rts51x_get_stat(chip) == RTS51X_STAT_RUN)
		rts51x_modi_suspend_timer(chip);
}

static int realtek_cr_autosuspend_setup(struct us_data *us)
{
	struct rts51x_chip *chip;
	struct rts51x_status *status = NULL;
	u8 buf[16];
	int retval;

	chip = (struct rts51x_chip *)us->extra;
	chip->support_auto_delink = 0;
	chip->pwr_state = US_RESUME;
	chip->lun_ready = 0;
	rts51x_set_stat(chip, RTS51X_STAT_INIT);

	retval = rts51x_read_status(us, 0, buf, 16, &(chip->status_len));
	if (retval != STATUS_SUCCESS) {
		usb_stor_dbg(us, "Read status fail\n");
		return -EIO;
	}
	status = chip->status;
	status->vid = ((u16) buf[0] << 8) | buf[1];
	status->pid = ((u16) buf[2] << 8) | buf[3];
	status->cur_lun = buf[4];
	status->card_type = buf[5];
	status->total_lun = buf[6];
	status->fw_ver = ((u16) buf[7] << 8) | buf[8];
	status->phy_exist = buf[9];
	status->multi_flag = buf[10];
	status->multi_card = buf[11];
	status->log_exist = buf[12];
	if (chip->status_len == 16) {
		status->detailed_type.detailed_type1 = buf[13];
		status->function[0] = buf[14];
		status->function[1] = buf[15];
	}

	/* back up the proto_handler in us->extra */
	chip = (struct rts51x_chip *)(us->extra);
	chip->proto_handler_backup = us->proto_handler;
	/* Set the autosuspend_delay to 0 */
	pm_runtime_set_autosuspend_delay(&us->pusb_dev->dev, 0);
	/* override us->proto_handler setted in get_protocol() */
	us->proto_handler = rts51x_invoke_transport;

	chip->timer_expires = 0;
	setup_timer(&chip->rts51x_suspend_timer, rts51x_suspend_timer_fn,
			(unsigned long)chip);
	fw5895_init(us);

	/* enable autosuspend function of the usb device */
	usb_enable_autosuspend(us->pusb_dev);

	return 0;
}
#endif

static void realtek_cr_destructor(void *extra)
{
	struct rts51x_chip *chip = extra;

	if (!chip)
		return;

#ifdef CONFIG_REALTEK_AUTOPM
	if (ss_en) {
		del_timer(&chip->rts51x_suspend_timer);
		chip->timer_expires = 0;
	}
#endif
	kfree(chip->status);
}

#ifdef CONFIG_PM
static int realtek_cr_suspend(struct usb_interface *iface, pm_message_t message)
{
	struct us_data *us = usb_get_intfdata(iface);

	/* wait until no command is running */
	mutex_lock(&us->dev_mutex);

	config_autodelink_before_power_down(us);

	mutex_unlock(&us->dev_mutex);

	return 0;
}

static int realtek_cr_resume(struct usb_interface *iface)
{
	struct us_data *us = usb_get_intfdata(iface);

	fw5895_init(us);
	config_autodelink_after_power_on(us);

	return 0;
}
#else
#define realtek_cr_suspend	NULL
#define realtek_cr_resume	NULL
#endif

static int init_realtek_cr(struct us_data *us)
{
	struct rts51x_chip *chip;
	int size, i, retval;

	chip = kzalloc(sizeof(struct rts51x_chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	us->extra = chip;
	us->extra_destructor = realtek_cr_destructor;
	us->max_lun = chip->max_lun = rts51x_get_max_lun(us);
	chip->us = us;

	usb_stor_dbg(us, "chip->max_lun = %d\n", chip->max_lun);

	size = (chip->max_lun + 1) * sizeof(struct rts51x_status);
	chip->status = kzalloc(size, GFP_KERNEL);
	if (!chip->status)
		goto INIT_FAIL;

	for (i = 0; i <= (int)(chip->max_lun); i++) {
		retval = rts51x_check_status(us, (u8) i);
		if (retval < 0)
			goto INIT_FAIL;
	}

	if (CHECK_PID(chip, 0x0138) || CHECK_PID(chip, 0x0158) ||
	    CHECK_PID(chip, 0x0159)) {
		if (CHECK_FW_VER(chip, 0x5888) || CHECK_FW_VER(chip, 0x5889) ||
				CHECK_FW_VER(chip, 0x5901))
			SET_AUTO_DELINK(chip);
		if (STATUS_LEN(chip) == 16) {
			if (SUPPORT_AUTO_DELINK(chip))
				SET_AUTO_DELINK(chip);
		}
	}
#ifdef CONFIG_REALTEK_AUTOPM
	if (ss_en)
		realtek_cr_autosuspend_setup(us);
#endif

	usb_stor_dbg(us, "chip->flag = 0x%x\n", chip->flag);

	(void)config_autodelink_after_power_on(us);

	return 0;

INIT_FAIL:
	if (us->extra) {
		kfree(chip->status);
		kfree(us->extra);
		us->extra = NULL;
	}

	return -EIO;
}

static struct scsi_host_template realtek_cr_host_template;

static int realtek_cr_probe(struct usb_interface *intf,
			    const struct usb_device_id *id)
{
	struct us_data *us;
	int result;

	dev_dbg(&intf->dev, "Probe Realtek Card Reader!\n");

	result = usb_stor_probe1(&us, intf, id,
				 (id - realtek_cr_ids) +
				 realtek_cr_unusual_dev_list,
				 &realtek_cr_host_template);
	if (result)
		return result;

	result = usb_stor_probe2(us);

	return result;
}

static struct usb_driver realtek_cr_driver = {
	.name = DRV_NAME,
	.probe = realtek_cr_probe,
	.disconnect = usb_stor_disconnect,
	/* .suspend =      usb_stor_suspend, */
	/* .resume =       usb_stor_resume, */
	.reset_resume = usb_stor_reset_resume,
	.suspend = realtek_cr_suspend,
	.resume = realtek_cr_resume,
	.pre_reset = usb_stor_pre_reset,
	.post_reset = usb_stor_post_reset,
	.id_table = realtek_cr_ids,
	.soft_unbind = 1,
	.supports_autosuspend = 1,
	.no_dynamic_id = 1,
};

module_usb_stor_driver(realtek_cr_driver, realtek_cr_host_template, DRV_NAME);