path: root/drivers/misc/cardreader/rtsx_usb.c

// 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 = from_timer(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 (!del_timer_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