path: root/drivers/media/video/em28xx/em28xx-core.c

/*
   em28xx-core.c - driver for Empia EM2800/EM2820/2840 USB video capture devices

   Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
		      Markus Rechberger <mrechberger@gmail.com>
		      Mauro Carvalho Chehab <mchehab@infradead.org>
		      Sascha Sommer <saschasommer@freenet.de>

   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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/vmalloc.h>
#include <media/v4l2-common.h>

#include "em28xx.h"

/* #define ENABLE_DEBUG_ISOC_FRAMES */

static unsigned int core_debug;
module_param(core_debug, int, 0644);
MODULE_PARM_DESC(core_debug, "enable debug messages [core]");

#define em28xx_coredbg(fmt, arg...) do {\
	if (core_debug) \
		printk(KERN_INFO "%s %s :"fmt, \
			 dev->name, __func__ , ##arg); } while (0)

static unsigned int reg_debug;
module_param(reg_debug, int, 0644);
MODULE_PARM_DESC(reg_debug, "enable debug messages [URB reg]");

#define em28xx_regdbg(fmt, arg...) do {\
	if (reg_debug) \
		printk(KERN_INFO "%s %s :"fmt, \
			 dev->name, __func__ , ##arg); } while (0)

static int alt = EM28XX_PINOUT;
module_param(alt, int, 0644);
MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");

/* FIXME */
#define em28xx_isocdbg(fmt, arg...) do {\
	if (core_debug) \
		printk(KERN_INFO "%s %s :"fmt, \
			 dev->name, __func__ , ##arg); } while (0)

/*
 * em28xx_read_reg_req()
 * reads data from the usb device specifying bRequest
 */
int em28xx_read_reg_req_len(struct em28xx *dev, u8 req, u16 reg,
				   char *buf, int len)
{
	int ret;
	int pipe = usb_rcvctrlpipe(dev->udev, 0);

	if (dev->state & DEV_DISCONNECTED)
		return -ENODEV;

	if (len > URB_MAX_CTRL_SIZE)
		return -EINVAL;

	if (reg_debug) {
		printk(KERN_DEBUG "(pipe 0x%08x): "
			"IN:  %02x %02x %02x %02x %02x %02x %02x %02x ",
			pipe,
			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			req, 0, 0,
			reg & 0xff, reg >> 8,
			len & 0xff, len >> 8);
	}

	mutex_lock(&dev->ctrl_urb_lock);
	ret = usb_control_msg(dev->udev, pipe, req,
			      USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			      0x0000, reg, dev->urb_buf, len, HZ);
	if (ret < 0) {
		if (reg_debug)
			printk(" failed!\n");
		mutex_unlock(&dev->ctrl_urb_lock);
		return ret;
	}

	if (len)
		memcpy(buf, dev->urb_buf, len);

	mutex_unlock(&dev->ctrl_urb_lock);

	if (reg_debug) {
		int byte;

		printk("<<<");
		for (byte = 0; byte < len; byte++)
			printk(" %02x", (unsigned char)buf[byte]);
		printk("\n");
	}

	return ret;
}

/*
 * em28xx_read_reg_req()
 * reads data from the usb device specifying bRequest
 */
int em28xx_read_reg_req(struct em28xx *dev, u8 req, u16 reg)
{
	int ret;
	u8 val;

	ret = em28xx_read_reg_req_len(dev, req, reg, &val, 1);
	if (ret < 0)
		return ret;

	return val;
}

int em28xx_read_reg(struct em28xx *dev, u16 reg)<