V4L/DVB: gscpa_sonixb: Differentiate between sensors with a coarse and fine expo ctrl

Some sensors only allow controlling the exposure by changing the clockdiv,
which means that exposure takes pretty large jumps (for example when going
from a div of 1 to 2, the exposure doubles). Use 2 different entries in
the controls array for these 2 different types of exposure (always
disabling one), and;

Add a new autogain algorithm for the coarse exposure case, which normally
changes the gain setting, only touching the exposure setting if the desired
luminance cannot be reached with gain, and after an exposure change once more
first tries gain, etc. Thus avoiding exposure changes, and the resulting
oscilation because of the huge steps these exposure controls take.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 75 insertions, 38 deletions

diff --git a/drivers/media/video/gspca/sonixb.c b/drivers/media/video/gspca/sonixb.c
index 4356423c6f99..dc2d88cdd4a2 100644
--- a/drivers/media/video/gspca/sonixb.c
+++ b/drivers/media/video/gspca/sonixb.c
@@ -54,9 +54,11 @@ struct sd {
         struct gspca_dev gspca_dev;     /* !! must be the first item */
         atomic_t avg_lum;
         int prev_avg_lum;
+        int exp_too_low_cnt;
+        int exp_too_high_cnt;
 
+        unsigned short exposure;
         unsigned char gain;
-        unsigned char exposure;
         unsigned char brightness;
         unsigned char autogain;
         unsigned char autogain_ignore_frames;
@@ -97,13 +99,15 @@ struct sensor_data {
 /* sensor_data flags */
 #define F_GAIN 0x01             /* has gain */
 #define F_SIF  0x02             /* sif or vga */
+#define F_COARSE_EXPO 0x04      /* exposure control is coarse */
 
 /* priv field of struct v4l2_pix_format flags (do not use low nibble!) */
 #define MODE_RAW 0x10           /* raw bayer mode */
 #define MODE_REDUCED_SIF 0x20   /* vga mode (320x240 / 160x120) on sif cam */
 
 /* ctrl_dis helper macros */
-#define NO_EXPO ((1 << EXPOSURE_IDX) | (1 << AUTOGAIN_IDX))
+#define NO_EXPO ((1 << EXPOSURE_IDX) | (1 << COARSE_EXPOSURE_IDX) | \
+                 (1 << AUTOGAIN_IDX))
 #define NO_FREQ (1 << FREQ_IDX)
 #define NO_BRIGHTNESS (1 << BRIGHTNESS_IDX)
 
@@ -129,11 +133,10 @@ struct sensor_data {
 }
 
 /* We calculate the autogain at the end of the transfer of a frame, at this
-   moment a frame with the old settings is being transmitted, and a frame is
-   being captured with the old settings. So if we adjust the autogain we must
-   ignore atleast the 2 next frames for the new settings to come into effect
-   before doing any other adjustments */
-#define AUTOGAIN_IGNORE_FRAMES 3
+   moment a frame with the old settings is being captured and transmitted. So
+   if we adjust the gain or exposure we must ignore atleast the next frame for
+   the new settings to come into effect before doing any other adjustments. */
+#define AUTOGAIN_IGNORE_FRAMES 1
 
 /* V4L2 controls supported by the driver */
 static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val);
@@ -185,10 +188,10 @@ static const struct ctrl sd_ctrls[] = {
                         .id = V4L2_CID_EXPOSURE,
                         .type = V4L2_CTRL_TYPE_INTEGER,
                         .name = "Exposure",
-#define EXPOSURE_DEF  16 /*  32 ms / 30 fps */
-#define EXPOSURE_KNEE 50 /* 100 ms / 10 fps */
+#define EXPOSURE_DEF  33 /*  33 ms / 30 fps */
+#define EXPOSURE_KNEE 100 /* 100 ms / 10 fps */
                         .minimum = 0,
-                        .maximum = 255,
+                        .maximum = 511,
                         .step = 1,
                         .default_value = EXPOSURE_DEF,
                         .flags = 0,
@@ -196,7 +199,23 @@ static const struct ctrl sd_ctrls[] = {
                 .set = sd_setexposure,
                 .get = sd_getexposure,
         },
-#define AUTOGAIN_IDX 3
+#define COARSE_EXPOSURE_IDX 3
+        {
+                {
+                        .id = V4L2_CID_EXPOSURE,
+                        .type = V4L2_CTRL_TYPE_INTEGER,
+                        .name = "Exposure",
+#define COARSE_EXPOSURE_DEF  2 /* 30 fps */
+                        .minimum = 2,
+                        .maximum = 15,
+                        .step = 1,
+                        .default_value = COARSE_EXPOSURE_DEF,
+                        .flags = 0,
+                },
+                .set = sd_setexposure,
+                .get = sd_getexposure,
+        },
+#define AUTOGAIN_IDX 4
         {
                 {
                         .id = V4L2_CID_AUTOGAIN,
@@ -212,7 +231,7 @@ static const struct ctrl sd_ctrls[] = {
                 .set = sd_setautogain,
                 .get = sd_getautogain,
         },
-#define FREQ_IDX 4
+#define FREQ_IDX 5
         {
                 {
                         .id      = V4L2_CID_POWER_LINE_FREQUENCY,
@@ -507,10 +526,10 @@ SENS(initPas106, NULL, pas106_sensor_init, NULL, NULL, F_SIF, NO_EXPO|NO_FREQ,
         0),
 SENS(initPas202, initPas202, pas202_sensor_init, NULL, NULL, 0,
         NO_EXPO|NO_FREQ, 0),
-SENS(initTas5110c, NULL, tas5110_sensor_init, NULL, NULL, F_GAIN|F_SIF,
-        NO_BRIGHTNESS|NO_FREQ, 0),
-SENS(initTas5110d, NULL, tas5110_sensor_init, NULL, NULL, F_GAIN|F_SIF,
-        NO_BRIGHTNESS|NO_FREQ, 0),
+SENS(initTas5110c, NULL, tas5110_sensor_init, NULL, NULL,
+        F_GAIN|F_SIF|F_COARSE_EXPO, NO_BRIGHTNESS|NO_FREQ, 0),
+SENS(initTas5110d, NULL, tas5110_sensor_init, NULL, NULL,
+        F_GAIN|F_SIF|F_COARSE_EXPO, NO_BRIGHTNESS|NO_FREQ, 0),
 SENS(initTas5130, NULL, tas5130_sensor_init, NULL, NULL, 0, NO_EXPO|NO_FREQ,
         0),
 };
@@ -721,16 +740,10 @@ static void setexposure(struct gspca_dev *gspca_dev)
         switch (sd->sensor) {
         case SENSOR_TAS5110C:
         case SENSOR_TAS5110D: {
-                __u8 reg;
-
                 /* register 19's high nibble contains the sn9c10x clock divider
                    The high nibble configures the no fps according to the
                    formula: 60 / high_nibble. With a maximum of 30 fps */
-                reg = 120 * sd->exposure / 1000;
-                if (reg < 2)
-                        reg = 2;
-                else if (reg > 15)
-                        reg = 15;
+                __u8 reg = sd->exposure;
                 reg = (reg << 4) | 0x0b;
                 reg_w(gspca_dev, 0x19, &reg, 1);
                 break;
@@ -766,7 +779,7 @@ static void setexposure(struct gspca_dev *gspca_dev)
                 } else
                         reg10_max = 0x41;
 
-                reg11 = (60 * sd->exposure + 999) / 1000;
+                reg11 = (30 * sd->exposure + 999) / 1000;
                 if (reg11 < 1)
                         reg11 = 1;
                 else if (reg11 > 16)
@@ -778,8 +791,8 @@ static void setexposure(struct gspca_dev *gspca_dev)
                         reg11 = 3;
 
                 /* frame exposure time in ms = 1000 * reg11 / 30    ->
-                reg10 = sd->exposure * 2 * reg10_max / (1000 * reg11 / 30) */
-                reg10 = (sd->exposure * 60 * reg10_max) / (1000 * reg11);
+                reg10 = sd->exposure * reg10_max / (1000 * reg11 / 30) */
+                reg10 = (sd->exposure * 30 * reg10_max) / (1000 * reg11);
 
                 /* Don't allow this to get below 10 when using autogain, the
                    steps become very large (relatively) when below 10 causing
@@ -839,30 +852,43 @@ static void setfreq(struct gspca_dev *gspca_dev)
         }
 }
 
+#include "coarse_expo_autogain.h"
+
 static void do_autogain(struct gspca_dev *gspca_dev)
 {
-        int deadzone, desired_avg_lum;
+        int deadzone, desired_avg_lum, result;
         struct sd *sd = (struct sd *) gspca_dev;
         int avg_lum = atomic_read(&sd->avg_lum);
 
-        if (avg_lum == -1)
+        if (avg_lum == -1 || !sd->autogain)
+                return;
+
+        if (sd->autogain_ignore_frames > 0) {
+                sd->autogain_ignore_frames--;
                 return;
+        }
 
         /* SIF / VGA sensors have a different autoexposure area and thus
            different avg_lum values for the same picture brightness */
         if (sensor_data[sd->sensor].flags & F_SIF) {
-                deadzone = 1000;
-                desired_avg_lum = 7000;
+                deadzone = 500;
+                /* SIF sensors tend to overexpose, so keep this small */
+                desired_avg_lum = 5000;
         } else {
-                deadzone = 3000;
+                deadzone = 1500;
                 desired_avg_lum = 23000;
         }
 
-        if (sd->autogain_ignore_frames > 0)
-                sd->autogain_ignore_frames--;
-        else if (gspca_auto_gain_n_exposure(gspca_dev, avg_lum,
-                        sd->brightness * desired_avg_lum / 127,
-                        deadzone, GAIN_KNEE, EXPOSURE_KNEE)) {
+        if (sensor_data[sd->sensor].flags & F_COARSE_EXPO)
+                result = gspca_coarse_grained_expo_autogain(gspca_dev, avg_lum,
+                                sd->brightness * desired_avg_lum / 127,
+                                deadzone);
+        else
+                result = gspca_auto_gain_n_exposure(gspca_dev, avg_lum,
+                                sd->brightness * desired_avg_lum / 127,
+                                deadzone, GAIN_KNEE, EXPOSURE_KNEE);
+
+        if (result) {
                 PDEBUG(D_FRAM, "autogain: gain changed: gain: %d expo: %d",
                         (int)sd->gain, (int)sd->exposure);
                 sd->autogain_ignore_frames = AUTOGAIN_IGNORE_FRAMES;
@@ -897,7 +923,13 @@ static int sd_config(struct gspca_dev *gspca_dev,
 
         sd->brightness = BRIGHTNESS_DEF;
         sd->gain = GAIN_DEF;
-        sd->exposure = EXPOSURE_DEF;
+        if (sensor_data[sd->sensor].flags & F_COARSE_EXPO) {
+                sd->exposure = COARSE_EXPOSURE_DEF;
+                gspca_dev->ctrl_dis |= (1 << EXPOSURE_IDX);
+        } else {
+                sd->exposure = EXPOSURE_DEF;
+                gspca_dev->ctrl_dis |= (1 << COARSE_EXPOSURE_IDX);
+        }
         if (gspca_dev->ctrl_dis & (1 << AUTOGAIN_IDX))
                 sd->autogain = 0; /* Disable do_autogain callback */
         else
@@ -1001,6 +1033,8 @@ static int sd_start(struct gspca_dev *gspca_dev)
 
         sd->frames_to_drop = 0;
         sd->autogain_ignore_frames = 0;
+        sd->exp_too_high_cnt = 0;
+        sd->exp_too_low_cnt = 0;
         atomic_set(&sd->avg_lum, -1);
         return 0;
 }
@@ -1159,11 +1193,14 @@ static int sd_setautogain(struct gspca_dev *gspca_dev, __s32 val)
         struct sd *sd = (struct sd *) gspca_dev;
 
         sd->autogain = val;
+        sd->exp_too_high_cnt = 0;
+        sd->exp_too_low_cnt = 0;
+
         /* when switching to autogain set defaults to make sure
            we are on a valid point of the autogain gain /
            exposure knee graph, and give this change time to
            take effect before doing autogain. */
-        if (sd->autogain) {
+        if (sd->autogain && !(sensor_data[sd->sensor].flags & F_COARSE_EXPO)) {
                 sd->exposure = EXPOSURE_DEF;
                 sd->gain = GAIN_DEF;
                 if (gspca_dev->streaming) {