linux/drivers/media/usb/gspca/stv0680.c
Colin Ian King 9b950ce057 media: gspca: remove redundant assignment to variable ret
The variable ret is being initialized with a value that
is never read and is being re-assigned a little later on. The
assignment is redundant and hence can be removed.

Addresses-Coverity: ("Unused value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-10-24 18:32:52 -03:00

340 lines
9.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* STV0680 USB Camera Driver
*
* Copyright (C) 2009 Hans de Goede <hdegoede@redhat.com>
*
* This module is adapted from the in kernel v4l1 stv680 driver:
*
* STV0680 USB Camera Driver, by Kevin Sisson (kjsisson@bellsouth.net)
*
* Thanks to STMicroelectronics for information on the usb commands, and
* to Steve Miller at STM for his help and encouragement while I was
* writing this driver.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define MODULE_NAME "stv0680"
#include "gspca.h"
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("STV0680 USB Camera Driver");
MODULE_LICENSE("GPL");
/* specific webcam descriptor */
struct sd {
struct gspca_dev gspca_dev; /* !! must be the first item */
struct v4l2_pix_format mode;
u8 orig_mode;
u8 video_mode;
u8 current_mode;
};
static int stv_sndctrl(struct gspca_dev *gspca_dev, int set, u8 req, u16 val,
int size)
{
int ret;
u8 req_type = 0;
unsigned int pipe = 0;
switch (set) {
case 0: /* 0xc1 */
req_type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT;
pipe = usb_rcvctrlpipe(gspca_dev->dev, 0);
break;
case 1: /* 0x41 */
req_type = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT;
pipe = usb_sndctrlpipe(gspca_dev->dev, 0);
break;
case 2: /* 0x80 */
req_type = USB_DIR_IN | USB_RECIP_DEVICE;
pipe = usb_rcvctrlpipe(gspca_dev->dev, 0);
break;
case 3: /* 0x40 */
req_type = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
pipe = usb_sndctrlpipe(gspca_dev->dev, 0);
break;
}
ret = usb_control_msg(gspca_dev->dev, pipe,
req, req_type,
val, 0, gspca_dev->usb_buf, size, 500);
if ((ret < 0) && (req != 0x0a))
pr_err("usb_control_msg error %i, request = 0x%x, error = %i\n",
set, req, ret);
return ret;
}
static int stv0680_handle_error(struct gspca_dev *gspca_dev, int ret)
{
stv_sndctrl(gspca_dev, 0, 0x80, 0, 0x02); /* Get Last Error */
gspca_err(gspca_dev, "last error: %i, command = 0x%x\n",
gspca_dev->usb_buf[0], gspca_dev->usb_buf[1]);
return ret;
}
static int stv0680_get_video_mode(struct gspca_dev *gspca_dev)
{
/* Note not sure if this init of usb_buf is really necessary */
memset(gspca_dev->usb_buf, 0, 8);
gspca_dev->usb_buf[0] = 0x0f;
if (stv_sndctrl(gspca_dev, 0, 0x87, 0, 0x08) != 0x08) {
gspca_err(gspca_dev, "Get_Camera_Mode failed\n");
return stv0680_handle_error(gspca_dev, -EIO);
}
return gspca_dev->usb_buf[0]; /* 01 = VGA, 03 = QVGA, 00 = CIF */
}
static int stv0680_set_video_mode(struct gspca_dev *gspca_dev, u8 mode)
{
struct sd *sd = (struct sd *) gspca_dev;
if (sd->current_mode == mode)
return 0;
memset(gspca_dev->usb_buf, 0, 8);
gspca_dev->usb_buf[0] = mode;
if (stv_sndctrl(gspca_dev, 3, 0x07, 0x0100, 0x08) != 0x08) {
gspca_err(gspca_dev, "Set_Camera_Mode failed\n");
return stv0680_handle_error(gspca_dev, -EIO);
}
/* Verify we got what we've asked for */
if (stv0680_get_video_mode(gspca_dev) != mode) {
gspca_err(gspca_dev, "Error setting camera video mode!\n");
return -EIO;
}
sd->current_mode = mode;
return 0;
}
/* this function is called at probe time */
static int sd_config(struct gspca_dev *gspca_dev,
const struct usb_device_id *id)
{
int ret;
struct sd *sd = (struct sd *) gspca_dev;
struct cam *cam = &gspca_dev->cam;
/* Give the camera some time to settle, otherwise initialization will
fail on hotplug, and yes it really needs a full second. */
msleep(1000);
/* ping camera to be sure STV0680 is present */
if (stv_sndctrl(gspca_dev, 0, 0x88, 0x5678, 0x02) != 0x02 ||
gspca_dev->usb_buf[0] != 0x56 || gspca_dev->usb_buf[1] != 0x78) {
gspca_err(gspca_dev, "STV(e): camera ping failed!!\n");
return stv0680_handle_error(gspca_dev, -ENODEV);
}
/* get camera descriptor */
if (stv_sndctrl(gspca_dev, 2, 0x06, 0x0200, 0x09) != 0x09)
return stv0680_handle_error(gspca_dev, -ENODEV);
if (stv_sndctrl(gspca_dev, 2, 0x06, 0x0200, 0x22) != 0x22 ||
gspca_dev->usb_buf[7] != 0xa0 || gspca_dev->usb_buf[8] != 0x23) {
gspca_err(gspca_dev, "Could not get descriptor 0200\n");
return stv0680_handle_error(gspca_dev, -ENODEV);
}
if (stv_sndctrl(gspca_dev, 0, 0x8a, 0, 0x02) != 0x02)
return stv0680_handle_error(gspca_dev, -ENODEV);
if (stv_sndctrl(gspca_dev, 0, 0x8b, 0, 0x24) != 0x24)
return stv0680_handle_error(gspca_dev, -ENODEV);
if (stv_sndctrl(gspca_dev, 0, 0x85, 0, 0x10) != 0x10)
return stv0680_handle_error(gspca_dev, -ENODEV);
if (!(gspca_dev->usb_buf[7] & 0x09)) {
gspca_err(gspca_dev, "Camera supports neither CIF nor QVGA mode\n");
return -ENODEV;
}
if (gspca_dev->usb_buf[7] & 0x01)
gspca_dbg(gspca_dev, D_PROBE, "Camera supports CIF mode\n");
if (gspca_dev->usb_buf[7] & 0x02)
gspca_dbg(gspca_dev, D_PROBE, "Camera supports VGA mode\n");
if (gspca_dev->usb_buf[7] & 0x04)
gspca_dbg(gspca_dev, D_PROBE, "Camera supports QCIF mode\n");
if (gspca_dev->usb_buf[7] & 0x08)
gspca_dbg(gspca_dev, D_PROBE, "Camera supports QVGA mode\n");
if (gspca_dev->usb_buf[7] & 0x01)
sd->video_mode = 0x00; /* CIF */
else
sd->video_mode = 0x03; /* QVGA */
/* FW rev, ASIC rev, sensor ID */
gspca_dbg(gspca_dev, D_PROBE, "Firmware rev is %i.%i\n",
gspca_dev->usb_buf[0], gspca_dev->usb_buf[1]);
gspca_dbg(gspca_dev, D_PROBE, "ASIC rev is %i.%i",
gspca_dev->usb_buf[2], gspca_dev->usb_buf[3]);
gspca_dbg(gspca_dev, D_PROBE, "Sensor ID is %i",
(gspca_dev->usb_buf[4]*16) + (gspca_dev->usb_buf[5]>>4));
ret = stv0680_get_video_mode(gspca_dev);
if (ret < 0)
return ret;
sd->current_mode = sd->orig_mode = ret;
ret = stv0680_set_video_mode(gspca_dev, sd->video_mode);
if (ret < 0)
return ret;
/* Get mode details */
if (stv_sndctrl(gspca_dev, 0, 0x8f, 0, 0x10) != 0x10)
return stv0680_handle_error(gspca_dev, -EIO);
cam->bulk = 1;
cam->bulk_nurbs = 1; /* The cam cannot handle more */
cam->bulk_size = (gspca_dev->usb_buf[0] << 24) |
(gspca_dev->usb_buf[1] << 16) |
(gspca_dev->usb_buf[2] << 8) |
(gspca_dev->usb_buf[3]);
sd->mode.width = (gspca_dev->usb_buf[4] << 8) |
(gspca_dev->usb_buf[5]); /* 322, 356, 644 */
sd->mode.height = (gspca_dev->usb_buf[6] << 8) |
(gspca_dev->usb_buf[7]); /* 242, 292, 484 */
sd->mode.pixelformat = V4L2_PIX_FMT_STV0680;
sd->mode.field = V4L2_FIELD_NONE;
sd->mode.bytesperline = sd->mode.width;
sd->mode.sizeimage = cam->bulk_size;
sd->mode.colorspace = V4L2_COLORSPACE_SRGB;
/* origGain = gspca_dev->usb_buf[12]; */
cam->cam_mode = &sd->mode;
cam->nmodes = 1;
ret = stv0680_set_video_mode(gspca_dev, sd->orig_mode);
if (ret < 0)
return ret;
if (stv_sndctrl(gspca_dev, 2, 0x06, 0x0100, 0x12) != 0x12 ||
gspca_dev->usb_buf[8] != 0x53 || gspca_dev->usb_buf[9] != 0x05) {
pr_err("Could not get descriptor 0100\n");
return stv0680_handle_error(gspca_dev, -EIO);
}
return 0;
}
/* this function is called at probe and resume time */
static int sd_init(struct gspca_dev *gspca_dev)
{
return 0;
}
/* -- start the camera -- */
static int sd_start(struct gspca_dev *gspca_dev)
{
int ret;
struct sd *sd = (struct sd *) gspca_dev;
ret = stv0680_set_video_mode(gspca_dev, sd->video_mode);
if (ret < 0)
return ret;
if (stv_sndctrl(gspca_dev, 0, 0x85, 0, 0x10) != 0x10)
return stv0680_handle_error(gspca_dev, -EIO);
/* Start stream at:
0x0000 = CIF (352x288)
0x0100 = VGA (640x480)
0x0300 = QVGA (320x240) */
if (stv_sndctrl(gspca_dev, 1, 0x09, sd->video_mode << 8, 0x0) != 0x0)
return stv0680_handle_error(gspca_dev, -EIO);
return 0;
}
static void sd_stopN(struct gspca_dev *gspca_dev)
{
/* This is a high priority command; it stops all lower order cmds */
if (stv_sndctrl(gspca_dev, 1, 0x04, 0x0000, 0x0) != 0x0)
stv0680_handle_error(gspca_dev, -EIO);
}
static void sd_stop0(struct gspca_dev *gspca_dev)
{
struct sd *sd = (struct sd *) gspca_dev;
if (!sd->gspca_dev.present)
return;
stv0680_set_video_mode(gspca_dev, sd->orig_mode);
}
static void sd_pkt_scan(struct gspca_dev *gspca_dev,
u8 *data,
int len)
{
struct sd *sd = (struct sd *) gspca_dev;
/* Every now and then the camera sends a 16 byte packet, no idea
what it contains, but it is not image data, when this
happens the frame received before this packet is corrupt,
so discard it. */
if (len != sd->mode.sizeimage) {
gspca_dev->last_packet_type = DISCARD_PACKET;
return;
}
/* Finish the previous frame, we do this upon reception of the next
packet, even though it is already complete so that the strange 16
byte packets send after a corrupt frame can discard it. */
gspca_frame_add(gspca_dev, LAST_PACKET, NULL, 0);
/* Store the just received frame */
gspca_frame_add(gspca_dev, FIRST_PACKET, data, len);
}
/* sub-driver description */
static const struct sd_desc sd_desc = {
.name = MODULE_NAME,
.config = sd_config,
.init = sd_init,
.start = sd_start,
.stopN = sd_stopN,
.stop0 = sd_stop0,
.pkt_scan = sd_pkt_scan,
};
/* -- module initialisation -- */
static const struct usb_device_id device_table[] = {
{USB_DEVICE(0x0553, 0x0202)},
{USB_DEVICE(0x041e, 0x4007)},
{}
};
MODULE_DEVICE_TABLE(usb, device_table);
/* -- device connect -- */
static int sd_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
THIS_MODULE);
}
static struct usb_driver sd_driver = {
.name = MODULE_NAME,
.id_table = device_table,
.probe = sd_probe,
.disconnect = gspca_disconnect,
#ifdef CONFIG_PM
.suspend = gspca_suspend,
.resume = gspca_resume,
.reset_resume = gspca_resume,
#endif
};
module_usb_driver(sd_driver);