path: root/drivers/media/dvb/dvb-usb/af9035.c

/*
 * Afatech AF9035 DVB USB driver
 *
 * Copyright (C) 2009 Antti Palosaari <crope@iki.fi>
 * Copyright (C) 2012 Antti Palosaari <crope@iki.fi>
 *
 *    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 of the License, 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, write to the Free Software Foundation, Inc.,
 *    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "af9035.h"

DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
static DEFINE_MUTEX(af9035_usb_mutex);
static struct dvb_usb_device_properties af9035_properties[2];
static int af9035_properties_count = ARRAY_SIZE(af9035_properties);

static u16 af9035_checksum(const u8 *buf, size_t len)
{
	size_t i;
	u16 checksum = 0;

	for (i = 1; i < len; i++) {
		if (i % 2)
			checksum += buf[i] << 8;
		else
			checksum += buf[i];
	}
	checksum = ~checksum;

	return checksum;
}

static int af9035_ctrl_msg(struct usb_device *udev, struct usb_req *req)
{
#define BUF_LEN 64
#define REQ_HDR_LEN 4 /* send header size */
#define ACK_HDR_LEN 3 /* rece header size */
#define CHECKSUM_LEN 2
#define USB_TIMEOUT 2000

	int ret, msg_len, act_len;
	u8 buf[BUF_LEN];
	static u8 seq; /* packet sequence number */
	u16 checksum, tmp_checksum;

	/* buffer overflow check */
	if (req->wlen > (BUF_LEN - REQ_HDR_LEN - CHECKSUM_LEN) ||
		req->rlen > (BUF_LEN - ACK_HDR_LEN - CHECKSUM_LEN)) {
		pr_debug("%s: too much data wlen=%d rlen=%d\n", __func__,
				req->wlen, req->rlen);
		return -EINVAL;
	}

	if (mutex_lock_interruptible(&af9035_usb_mutex) < 0)
		return -EAGAIN;

	buf[0] = REQ_HDR_LEN + req->wlen + CHECKSUM_LEN - 1;
	buf[1] = req->mbox;
	buf[2] = req->cmd;
	buf[3] = seq++;
	if (req->wlen)
		memcpy(&buf[4], req->wbuf, req->wlen);

	/* calc and add checksum */
	checksum = af9035_checksum(buf, buf[0] - 1);
	buf[buf[0] - 1] = (checksum >> 8);
	buf[buf[0] - 0] = (checksum & 0xff);

	msg_len = REQ_HDR_LEN + req->wlen + CHECKSUM_LEN ;

	/* send req */
	ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, 0x02), buf, msg_len,
			&act_len, USB_TIMEOUT);
	if (ret < 0)
		err("bulk message failed=%d (%d/%d)", ret, msg_len, act_len);
	else
		if (act_len != msg_len)
			ret = -EIO; /* all data is not send */
	if (ret < 0)
		goto err_mutex_unlock;

	/* no ack for those packets */
	if (req->cmd == CMD_FW_DL)
		goto exit_mutex_unlock;

	/* receive ack and data if read req */
	msg_len = ACK_HDR_LEN + req->rlen + CHECKSUM_LEN;
	ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, 0x81), buf, msg_len,
			&act_len, USB_TIMEOUT);
	if (ret < 0) {
		err("recv bulk message failed=%d", ret);
		ret = -EIO;
		goto err_mutex_unlock;
	}

	if (act_len != msg_len) {
		err("recv bulk message truncated (%d != %d)", act_len, msg_len);
		ret = -EIO;
		goto err_mutex_unlock;
	}

	/* verify checksum */
	checksum = af9035_checksum(buf, act_len - 2);
	tmp_checksum = (buf[act_len - 2] << 8) | buf[act_len - 1];
	if (tmp_checksum != checksum) {
		err("%s: command=%02x checksum mismatch (%04x != %04x)",
		    __func__, req->cmd, tmp_checksum, checksum);
		ret = -EIO;
		goto err_mutex_unlock;
	}

	/* check status */
	if (buf[2]) {
		pr_debug("%s: command=%02x failed fw error=%d\n", __func__,
				req->cmd, buf[2]);
		ret = -EIO;
		goto err_mutex_unlock;
	}

	/* read request, copy returned data to return buf */
	if (req->rlen)
		memcpy(req->rbuf, &buf[ACK_HDR_LEN], req->rlen);

err_mutex_unlock:
exit_mutex_unlock:
	mutex_unlock(&af9035_usb_mutex);

	return ret;
}

/* write multiple registers */
static int af9035_wr_regs(struct dvb_usb_device *d, u32 reg, u8 *val, int len)
{
	u8 wbuf[6 + len];
	u8 mbox = (reg >> 16) & 0xff;
	struct usb_req req = { CMD_MEM_WR, mbox, sizeof(wbuf), wbuf, 0, NULL };

	wbuf[0] = len;
	wbuf[1] = 2;
	wbuf[2] = 0;
	wbuf[3] = 0;
	wbuf[