kernel-ark/drivers/media/usb/gspca/jl2005bcd.c
Colin Ian King e1f60f426f media: gspca: remove redundant assignment to variable retval
The variable retval is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and 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+huawei@kernel.org>
2020-06-23 13:21:19 +02:00

523 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Jeilin JL2005B/C/D library
*
* Copyright (C) 2011 Theodore Kilgore <kilgota@auburn.edu>
*/
#define MODULE_NAME "jl2005bcd"
#include <linux/workqueue.h>
#include <linux/slab.h>
#include "gspca.h"
MODULE_AUTHOR("Theodore Kilgore <kilgota@auburn.edu>");
MODULE_DESCRIPTION("JL2005B/C/D USB Camera Driver");
MODULE_LICENSE("GPL");
/* Default timeouts, in ms */
#define JL2005C_CMD_TIMEOUT 500
#define JL2005C_DATA_TIMEOUT 1000
/* Maximum transfer size to use. */
#define JL2005C_MAX_TRANSFER 0x200
#define FRAME_HEADER_LEN 16
/* specific webcam descriptor */
struct sd {
struct gspca_dev gspca_dev; /* !! must be the first item */
unsigned char firmware_id[6];
const struct v4l2_pix_format *cap_mode;
/* Driver stuff */
struct work_struct work_struct;
u8 frame_brightness;
int block_size; /* block size of camera */
int vga; /* 1 if vga cam, 0 if cif cam */
};
/* Camera has two resolution settings. What they are depends on model. */
static const struct v4l2_pix_format cif_mode[] = {
{176, 144, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
.bytesperline = 176,
.sizeimage = 176 * 144,
.colorspace = V4L2_COLORSPACE_SRGB,
.priv = 0},
{352, 288, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
.bytesperline = 352,
.sizeimage = 352 * 288,
.colorspace = V4L2_COLORSPACE_SRGB,
.priv = 0},
};
static const struct v4l2_pix_format vga_mode[] = {
{320, 240, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
.bytesperline = 320,
.sizeimage = 320 * 240,
.colorspace = V4L2_COLORSPACE_SRGB,
.priv = 0},
{640, 480, V4L2_PIX_FMT_JL2005BCD, V4L2_FIELD_NONE,
.bytesperline = 640,
.sizeimage = 640 * 480,
.colorspace = V4L2_COLORSPACE_SRGB,
.priv = 0},
};
/*
* cam uses endpoint 0x03 to send commands, 0x84 for read commands,
* and 0x82 for bulk data transfer.
*/
/* All commands are two bytes only */
static int jl2005c_write2(struct gspca_dev *gspca_dev, unsigned char *command)
{
int retval;
memcpy(gspca_dev->usb_buf, command, 2);
retval = usb_bulk_msg(gspca_dev->dev,
usb_sndbulkpipe(gspca_dev->dev, 3),
gspca_dev->usb_buf, 2, NULL, 500);
if (retval < 0)
pr_err("command write [%02x] error %d\n",
gspca_dev->usb_buf[0], retval);
return retval;
}
/* Response to a command is one byte in usb_buf[0], only if requested. */
static int jl2005c_read1(struct gspca_dev *gspca_dev)
{
int retval;
retval = usb_bulk_msg(gspca_dev->dev,
usb_rcvbulkpipe(gspca_dev->dev, 0x84),
gspca_dev->usb_buf, 1, NULL, 500);
if (retval < 0)
pr_err("read command [0x%02x] error %d\n",
gspca_dev->usb_buf[0], retval);
return retval;
}
/* Response appears in gspca_dev->usb_buf[0] */
static int jl2005c_read_reg(struct gspca_dev *gspca_dev, unsigned char reg)
{
int retval;
static u8 instruction[2] = {0x95, 0x00};
/* put register to read in byte 1 */
instruction[1] = reg;
/* Send the read request */
retval = jl2005c_write2(gspca_dev, instruction);
if (retval < 0)
return retval;
retval = jl2005c_read1(gspca_dev);
return retval;
}
static int jl2005c_start_new_frame(struct gspca_dev *gspca_dev)
{
int i;
int retval;
int frame_brightness = 0;
static u8 instruction[2] = {0x7f, 0x01};
retval = jl2005c_write2(gspca_dev, instruction);
if (retval < 0)
return retval;
i = 0;
while (i < 20 && !frame_brightness) {
/* If we tried 20 times, give up. */
retval = jl2005c_read_reg(gspca_dev, 0x7e);
if (retval < 0)
return retval;
frame_brightness = gspca_dev->usb_buf[0];
retval = jl2005c_read_reg(gspca_dev, 0x7d);
if (retval < 0)
return retval;
i++;
}
gspca_dbg(gspca_dev, D_FRAM, "frame_brightness is 0x%02x\n",
gspca_dev->usb_buf[0]);
return retval;
}
static int jl2005c_write_reg(struct gspca_dev *gspca_dev, unsigned char reg,
unsigned char value)
{
int retval;
u8 instruction[2];
instruction[0] = reg;
instruction[1] = value;
retval = jl2005c_write2(gspca_dev, instruction);
if (retval < 0)
return retval;
return retval;
}
static int jl2005c_get_firmware_id(struct gspca_dev *gspca_dev)
{
struct sd *sd = (struct sd *)gspca_dev;
int i = 0;
int retval;
unsigned char regs_to_read[] = {0x57, 0x02, 0x03, 0x5d, 0x5e, 0x5f};
gspca_dbg(gspca_dev, D_PROBE, "Running jl2005c_get_firmware_id\n");
/* Read the first ID byte once for warmup */
retval = jl2005c_read_reg(gspca_dev, regs_to_read[0]);
gspca_dbg(gspca_dev, D_PROBE, "response is %02x\n",
gspca_dev->usb_buf[0]);
if (retval < 0)
return retval;
/* Now actually get the ID string */
for (i = 0; i < 6; i++) {
retval = jl2005c_read_reg(gspca_dev, regs_to_read[i]);
if (retval < 0)
return retval;
sd->firmware_id[i] = gspca_dev->usb_buf[0];
}
gspca_dbg(gspca_dev, D_PROBE, "firmware ID is %02x%02x%02x%02x%02x%02x\n",
sd->firmware_id[0],
sd->firmware_id[1],
sd->firmware_id[2],
sd->firmware_id[3],
sd->firmware_id[4],
sd->firmware_id[5]);
return 0;
}
static int jl2005c_stream_start_vga_lg
(struct gspca_dev *gspca_dev)
{
int i;
int retval = -1;
static u8 instruction[][2] = {
{0x05, 0x00},
{0x7c, 0x00},
{0x7d, 0x18},
{0x02, 0x00},
{0x01, 0x00},
{0x04, 0x52},
};
for (i = 0; i < ARRAY_SIZE(instruction); i++) {
msleep(60);
retval = jl2005c_write2(gspca_dev, instruction[i]);
if (retval < 0)
return retval;
}
msleep(60);
return retval;
}
static int jl2005c_stream_start_vga_small(struct gspca_dev *gspca_dev)
{
int i;
int retval = -1;
static u8 instruction[][2] = {
{0x06, 0x00},
{0x7c, 0x00},
{0x7d, 0x1a},
{0x02, 0x00},
{0x01, 0x00},
{0x04, 0x52},
};
for (i = 0; i < ARRAY_SIZE(instruction); i++) {
msleep(60);
retval = jl2005c_write2(gspca_dev, instruction[i]);
if (retval < 0)
return retval;
}
msleep(60);
return retval;
}
static int jl2005c_stream_start_cif_lg(struct gspca_dev *gspca_dev)
{
int i;
int retval = -1;
static u8 instruction[][2] = {
{0x05, 0x00},
{0x7c, 0x00},
{0x7d, 0x30},
{0x02, 0x00},
{0x01, 0x00},
{0x04, 0x42},
};
for (i = 0; i < ARRAY_SIZE(instruction); i++) {
msleep(60);
retval = jl2005c_write2(gspca_dev, instruction[i]);
if (retval < 0)
return retval;
}
msleep(60);
return retval;
}
static int jl2005c_stream_start_cif_small(struct gspca_dev *gspca_dev)
{
int i;
int retval = -1;
static u8 instruction[][2] = {
{0x06, 0x00},
{0x7c, 0x00},
{0x7d, 0x32},
{0x02, 0x00},
{0x01, 0x00},
{0x04, 0x42},
};
for (i = 0; i < ARRAY_SIZE(instruction); i++) {
msleep(60);
retval = jl2005c_write2(gspca_dev, instruction[i]);
if (retval < 0)
return retval;
}
msleep(60);
return retval;
}
static int jl2005c_stop(struct gspca_dev *gspca_dev)
{
return jl2005c_write_reg(gspca_dev, 0x07, 0x00);
}
/*
* This function is called as a workqueue function and runs whenever the camera
* is streaming data. Because it is a workqueue function it is allowed to sleep
* so we can use synchronous USB calls. To avoid possible collisions with other
* threads attempting to use gspca_dev->usb_buf we take the usb_lock when
* performing USB operations using it. In practice we don't really need this
* as the camera doesn't provide any controls.
*/
static void jl2005c_dostream(struct work_struct *work)
{
struct sd *dev = container_of(work, struct sd, work_struct);
struct gspca_dev *gspca_dev = &dev->gspca_dev;
int bytes_left = 0; /* bytes remaining in current frame. */
int data_len; /* size to use for the next read. */
int header_read = 0;
unsigned char header_sig[2] = {0x4a, 0x4c};
int act_len;
int packet_type;
int ret;
u8 *buffer;
buffer = kmalloc(JL2005C_MAX_TRANSFER, GFP_KERNEL);
if (!buffer) {
pr_err("Couldn't allocate USB buffer\n");
goto quit_stream;
}
while (gspca_dev->present && gspca_dev->streaming) {
#ifdef CONFIG_PM
if (gspca_dev->frozen)
break;
#endif
/* Check if this is a new frame. If so, start the frame first */
if (!header_read) {
mutex_lock(&gspca_dev->usb_lock);
ret = jl2005c_start_new_frame(gspca_dev);
mutex_unlock(&gspca_dev->usb_lock);
if (ret < 0)
goto quit_stream;
ret = usb_bulk_msg(gspca_dev->dev,
usb_rcvbulkpipe(gspca_dev->dev, 0x82),
buffer, JL2005C_MAX_TRANSFER, &act_len,
JL2005C_DATA_TIMEOUT);
gspca_dbg(gspca_dev, D_PACK,
"Got %d bytes out of %d for header\n",
act_len, JL2005C_MAX_TRANSFER);
if (ret < 0 || act_len < JL2005C_MAX_TRANSFER)
goto quit_stream;
/* Check whether we actually got the first blodk */
if (memcmp(header_sig, buffer, 2) != 0) {
pr_err("First block is not the first block\n");
goto quit_stream;
}
/* total size to fetch is byte 7, times blocksize
* of which we already got act_len */
bytes_left = buffer[0x07] * dev->block_size - act_len;
gspca_dbg(gspca_dev, D_PACK, "bytes_left = 0x%x\n",
bytes_left);
/* We keep the header. It has other information, too.*/
packet_type = FIRST_PACKET;
gspca_frame_add(gspca_dev, packet_type,
buffer, act_len);
header_read = 1;
}
while (bytes_left > 0 && gspca_dev->present) {
data_len = bytes_left > JL2005C_MAX_TRANSFER ?
JL2005C_MAX_TRANSFER : bytes_left;
ret = usb_bulk_msg(gspca_dev->dev,
usb_rcvbulkpipe(gspca_dev->dev, 0x82),
buffer, data_len, &act_len,
JL2005C_DATA_TIMEOUT);
if (ret < 0 || act_len < data_len)
goto quit_stream;
gspca_dbg(gspca_dev, D_PACK,
"Got %d bytes out of %d for frame\n",
data_len, bytes_left);
bytes_left -= data_len;
if (bytes_left == 0) {
packet_type = LAST_PACKET;
header_read = 0;
} else
packet_type = INTER_PACKET;
gspca_frame_add(gspca_dev, packet_type,
buffer, data_len);
}
}
quit_stream:
if (gspca_dev->present) {
mutex_lock(&gspca_dev->usb_lock);
jl2005c_stop(gspca_dev);
mutex_unlock(&gspca_dev->usb_lock);
}
kfree(buffer);
}
/* This function is called at probe time */
static int sd_config(struct gspca_dev *gspca_dev,
const struct usb_device_id *id)
{
struct cam *cam;
struct sd *sd = (struct sd *) gspca_dev;
cam = &gspca_dev->cam;
/* We don't use the buffer gspca allocates so make it small. */
cam->bulk_size = 64;
cam->bulk = 1;
/* For the rest, the camera needs to be detected */
jl2005c_get_firmware_id(gspca_dev);
/* Here are some known firmware IDs
* First some JL2005B cameras
* {0x41, 0x07, 0x04, 0x2c, 0xe8, 0xf2} Sakar KidzCam
* {0x45, 0x02, 0x08, 0xb9, 0x00, 0xd2} No-name JL2005B
* JL2005C cameras
* {0x01, 0x0c, 0x16, 0x10, 0xf8, 0xc8} Argus DC-1512
* {0x12, 0x04, 0x03, 0xc0, 0x00, 0xd8} ICarly
* {0x86, 0x08, 0x05, 0x02, 0x00, 0xd4} Jazz
*
* Based upon this scanty evidence, we can detect a CIF camera by
* testing byte 0 for 0x4x.
*/
if ((sd->firmware_id[0] & 0xf0) == 0x40) {
cam->cam_mode = cif_mode;
cam->nmodes = ARRAY_SIZE(cif_mode);
sd->block_size = 0x80;
} else {
cam->cam_mode = vga_mode;
cam->nmodes = ARRAY_SIZE(vga_mode);
sd->block_size = 0x200;
}
INIT_WORK(&sd->work_struct, jl2005c_dostream);
return 0;
}
/* this function is called at probe and resume time */
static int sd_init(struct gspca_dev *gspca_dev)
{
return 0;
}
static int sd_start(struct gspca_dev *gspca_dev)
{
struct sd *sd = (struct sd *) gspca_dev;
sd->cap_mode = gspca_dev->cam.cam_mode;
switch (gspca_dev->pixfmt.width) {
case 640:
gspca_dbg(gspca_dev, D_STREAM, "Start streaming at vga resolution\n");
jl2005c_stream_start_vga_lg(gspca_dev);
break;
case 320:
gspca_dbg(gspca_dev, D_STREAM, "Start streaming at qvga resolution\n");
jl2005c_stream_start_vga_small(gspca_dev);
break;
case 352:
gspca_dbg(gspca_dev, D_STREAM, "Start streaming at cif resolution\n");
jl2005c_stream_start_cif_lg(gspca_dev);
break;
case 176:
gspca_dbg(gspca_dev, D_STREAM, "Start streaming at qcif resolution\n");
jl2005c_stream_start_cif_small(gspca_dev);
break;
default:
pr_err("Unknown resolution specified\n");
return -1;
}
schedule_work(&sd->work_struct);
return 0;
}
/* called on streamoff with alt==0 and on disconnect */
/* the usb_lock is held at entry - restore on exit */
static void sd_stop0(struct gspca_dev *gspca_dev)
{
struct sd *dev = (struct sd *) gspca_dev;
/* wait for the work queue to terminate */
mutex_unlock(&gspca_dev->usb_lock);
/* This waits for sq905c_dostream to finish */
flush_work(&dev->work_struct);
mutex_lock(&gspca_dev->usb_lock);
}
/* sub-driver description */
static const struct sd_desc sd_desc = {
.name = MODULE_NAME,
.config = sd_config,
.init = sd_init,
.start = sd_start,
.stop0 = sd_stop0,
};
/* -- module initialisation -- */
static const struct usb_device_id device_table[] = {
{USB_DEVICE(0x0979, 0x0227)},
{}
};
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);