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V4L/DVB (13242): gspca_mr97310a: Add minimum clock divider control
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When "shooting" certain (quite rare) scenes, the mr97310's compression is not
effective and it cannot keep up with the data stream. This patch adds a
minimum clock divider control, which influences the maximum framerate,
libv4l will automatically increase this minimum clockdiv control when it
detect the cam cannot keep up.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Hans de Goede authored and Mauro Carvalho Chehab committed Dec 5, 2009
1 parent f14a297 commit 065b6f7
Showing 1 changed file with 51 additions and 6 deletions.
57 changes: 51 additions & 6 deletions drivers/media/video/gspca/mr97310a.c
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Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,10 @@
#define MR97310A_GAIN_MAX 31
#define MR97310A_GAIN_DEFAULT 25

#define MR97310A_MIN_CLOCKDIV_MIN 3
#define MR97310A_MIN_CLOCKDIV_MAX 8
#define MR97310A_MIN_CLOCKDIV_DEFAULT 3

MODULE_AUTHOR("Kyle Guinn <elyk03@gmail.com>,"
"Theodore Kilgore <kilgota@auburn.edu>");
MODULE_DESCRIPTION("GSPCA/Mars-Semi MR97310A USB Camera Driver");
Expand All @@ -76,6 +80,7 @@ struct sd {
int brightness;
u16 exposure;
u8 gain;
u8 min_clockdiv;
};

struct sensor_w_data {
Expand All @@ -92,6 +97,8 @@ static int sd_setexposure(struct gspca_dev *gspca_dev, __s32 val);
static int sd_getexposure(struct gspca_dev *gspca_dev, __s32 *val);
static int sd_setgain(struct gspca_dev *gspca_dev, __s32 val);
static int sd_getgain(struct gspca_dev *gspca_dev, __s32 *val);
static int sd_setmin_clockdiv(struct gspca_dev *gspca_dev, __s32 val);
static int sd_getmin_clockdiv(struct gspca_dev *gspca_dev, __s32 *val);
static void setbrightness(struct gspca_dev *gspca_dev);
static void setexposure(struct gspca_dev *gspca_dev);
static void setgain(struct gspca_dev *gspca_dev);
Expand Down Expand Up @@ -160,6 +167,21 @@ static struct ctrl sd_ctrls[] = {
.set = sd_setgain,
.get = sd_getgain,
},
{
#define MIN_CLOCKDIV_IDX 4
{
.id = V4L2_CID_PRIVATE_BASE,
.type = V4L2_CTRL_TYPE_INTEGER,
.name = "Minimum Clock Divider",
.minimum = MR97310A_MIN_CLOCKDIV_MIN,
.maximum = MR97310A_MIN_CLOCKDIV_MAX,
.step = 1,
.default_value = MR97310A_MIN_CLOCKDIV_DEFAULT,
.flags = 0,
},
.set = sd_setmin_clockdiv,
.get = sd_getmin_clockdiv,
},
};

static const struct v4l2_pix_format vga_mode[] = {
Expand Down Expand Up @@ -544,14 +566,16 @@ static int sd_config(struct gspca_dev *gspca_dev,
gspca_dev->ctrl_dis = (1 << NORM_BRIGHTNESS_IDX) |
(1 << ARGUS_QC_BRIGHTNESS_IDX);
else
gspca_dev->ctrl_dis = (1 << ARGUS_QC_BRIGHTNESS_IDX);
gspca_dev->ctrl_dis = (1 << ARGUS_QC_BRIGHTNESS_IDX) |
(1 << MIN_CLOCKDIV_IDX);
} else {
/* All controls need to be disabled if VGA sensor_type is 0 */
if (sd->sensor_type == 0)
gspca_dev->ctrl_dis = (1 << NORM_BRIGHTNESS_IDX) |
(1 << ARGUS_QC_BRIGHTNESS_IDX) |
(1 << EXPOSURE_IDX) |
(1 << GAIN_IDX);
(1 << GAIN_IDX) |
(1 << MIN_CLOCKDIV_IDX);
else if (sd->do_lcd_stop)
/* Argus QuickClix has different brightness limits */
gspca_dev->ctrl_dis = (1 << NORM_BRIGHTNESS_IDX);
Expand All @@ -562,6 +586,7 @@ static int sd_config(struct gspca_dev *gspca_dev,
sd->brightness = MR97310A_BRIGHTNESS_DEFAULT;
sd->exposure = MR97310A_EXPOSURE_DEFAULT;
sd->gain = MR97310A_GAIN_DEFAULT;
sd->min_clockdiv = MR97310A_MIN_CLOCKDIV_DEFAULT;

return 0;
}
Expand Down Expand Up @@ -837,6 +862,7 @@ static void setexposure(struct gspca_dev *gspca_dev)
{
struct sd *sd = (struct sd *) gspca_dev;
int exposure;
u8 buf[2];

if (gspca_dev->ctrl_dis & (1 << EXPOSURE_IDX))
return;
Expand All @@ -858,8 +884,8 @@ static void setexposure(struct gspca_dev *gspca_dev)
u8 clockdiv = (60 * sd->exposure + 7999) / 8000;

/* Limit framerate to not exceed usb bandwidth */
if (clockdiv < 3 && gspca_dev->width >= 320)
clockdiv = 3;
if (clockdiv < sd->min_clockdiv && gspca_dev->width >= 320)
clockdiv = sd->min_clockdiv;
else if (clockdiv < 2)
clockdiv = 2;

Expand All @@ -875,9 +901,10 @@ static void setexposure(struct gspca_dev *gspca_dev)
/* exposure register value is reversed! */
exposure = 511 - exposure;

buf[0] = exposure & 0xff;
buf[1] = exposure >> 8;
sensor_write_reg(gspca_dev, 0x0e, 0, buf, 2);
sensor_write1(gspca_dev, 0x02, clockdiv);
sensor_write1(gspca_dev, 0x0e, exposure & 0xff);
sensor_write1(gspca_dev, 0x0f, exposure >> 8);
}
}

Expand Down Expand Up @@ -949,6 +976,24 @@ static int sd_getgain(struct gspca_dev *gspca_dev, __s32 *val)
return 0;
}

static int sd_setmin_clockdiv(struct gspca_dev *gspca_dev, __s32 val)
{
struct sd *sd = (struct sd *) gspca_dev;

sd->min_clockdiv = val;
if (gspca_dev->streaming)
setexposure(gspca_dev);
return 0;
}

static int sd_getmin_clockdiv(struct gspca_dev *gspca_dev, __s32 *val)
{
struct sd *sd = (struct sd *) gspca_dev;

*val = sd->min_clockdiv;
return 0;
}

/* Include pac common sof detection functions */
#include "pac_common.h"

Expand Down

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