media: atomisp: gc0310: Add exposure and gain controls

Add exposure and gain controls. This allows controlling
the exposure and gain through standard v4l2 IOCTLs.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c b/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
index 1154936..cf85fb9 100644 (file)
--- a/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
@@ -57,14 +57,60 @@ static int gc0310_write_reg_array(struct i2c_client *client,
        return 0;
 }
 
+static int gc0310_exposure_set(struct gc0310_device *dev, u32 exp)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(&dev->sd);
+
+       return i2c_smbus_write_word_swapped(client, GC0310_AEC_PK_EXPO_H, exp);
+}
+
+static int gc0310_gain_set(struct gc0310_device *dev, u32 gain)
+{
+       struct i2c_client *client = v4l2_get_subdevdata(&dev->sd);
+       u8 again, dgain;
+       int ret;
+
+       /* Taken from original driver, this never sets dgain lower then 32? */
+
+       /* Change 0 - 95 to 32 - 127 */
+       gain += 32;
+
+       if (gain < 64) {
+               again = 0x0; /* sqrt(2) */
+               dgain = gain;
+       } else {
+               again = 0x2; /* 2 * sqrt(2) */
+               dgain = gain / 2;
+       }
+
+       ret = i2c_smbus_write_byte_data(client, GC0310_AGC_ADJ, again);
+       if (ret)
+               return ret;
+
+       return i2c_smbus_write_byte_data(client, GC0310_DGC_ADJ, dgain);
+}
+
 static int gc0310_s_ctrl(struct v4l2_ctrl *ctrl)
 {
-       int ret = 0;
+       struct gc0310_device *dev =
+               container_of(ctrl->handler, struct gc0310_device, ctrls.handler);
+       int ret;
+
+       if (!dev->power_on)
+               return 0;
 
        switch (ctrl->id) {
+       case V4L2_CID_EXPOSURE:
+               ret = gc0310_exposure_set(dev, ctrl->val);
+               break;
+       case V4L2_CID_GAIN:
+               ret = gc0310_gain_set(dev, ctrl->val);
+               break;
        default:
                ret = -EINVAL;
+               break;
        }
+
        return ret;
 }
 
@@ -83,13 +129,18 @@ static int gc0310_init(struct v4l2_subdev *sd)
        /* set initial registers */
        ret = gc0310_write_reg_array(client, gc0310_reset_register,
                                     ARRAY_SIZE(gc0310_reset_register));
+       if (ret)
+               goto out_unlock;
 
        /* restore settings */
        gc0310_res = gc0310_res_preview;
        N_RES = N_RES_PREVIEW;
 
-       mutex_unlock(&dev->input_lock);
+       /* restore value of all ctrls */
+       ret = __v4l2_ctrl_handler_setup(&dev->ctrls.handler);
 
+out_unlock:
+       mutex_unlock(&dev->input_lock);
        return ret;
 }
 
@@ -545,6 +596,26 @@ static const struct v4l2_subdev_ops gc0310_ops = {
        .sensor = &gc0310_sensor_ops,
 };
 
+static int gc0310_init_controls(struct gc0310_device *dev)
+{
+       struct v4l2_ctrl_handler *hdl = &dev->ctrls.handler;
+
+       v4l2_ctrl_handler_init(hdl, 2);
+
+       /* Use the same lock for controls as for everything else */
+       hdl->lock = &dev->input_lock;
+       dev->sd.ctrl_handler = hdl;
+
+       dev->ctrls.exposure =
+               v4l2_ctrl_new_std(hdl, &ctrl_ops, V4L2_CID_EXPOSURE, 0, 4095, 1, 1023);
+
+       /* 32 steps at base gain 1 + 64 half steps at base gain 2 */
+       dev->ctrls.gain =
+               v4l2_ctrl_new_std(hdl, &ctrl_ops, V4L2_CID_GAIN, 0, 95, 1, 31);
+
+       return hdl->error;
+}
+
 static void gc0310_remove(struct i2c_client *client)
 {
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
@@ -556,7 +627,7 @@ static void gc0310_remove(struct i2c_client *client)
 
        v4l2_device_unregister_subdev(sd);
        media_entity_cleanup(&dev->sd.entity);
-       v4l2_ctrl_handler_free(&dev->ctrl_handler);
+       v4l2_ctrl_handler_free(&dev->ctrls.handler);
        kfree(dev);
 }
 
@@ -595,21 +666,13 @@ static int gc0310_probe(struct i2c_client *client)
        dev->pad.flags = MEDIA_PAD_FL_SOURCE;
        dev->format.code = MEDIA_BUS_FMT_SGRBG8_1X8;
        dev->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
-       ret = v4l2_ctrl_handler_init(&dev->ctrl_handler, 0);
+
+       ret = gc0310_init_controls(dev);
        if (ret) {
                gc0310_remove(client);
                return ret;
        }
 
-       if (dev->ctrl_handler.error) {
-               gc0310_remove(client);
-               return dev->ctrl_handler.error;
-       }
-
-       /* Use same lock for controls as for everything else. */
-       dev->ctrl_handler.lock = &dev->input_lock;
-       dev->sd.ctrl_handler = &dev->ctrl_handler;
-
        ret = media_entity_pads_init(&dev->sd.entity, 1, &dev->pad);
        if (ret)
                gc0310_remove(client);

diff --git a/drivers/staging/media/atomisp/i2c/gc0310.h b/drivers/staging/media/atomisp/i2c/gc0310.h
index 540334b..c15ca2b 100644 (file)
--- a/drivers/staging/media/atomisp/i2c/gc0310.h
+++ b/drivers/staging/media/atomisp/i2c/gc0310.h
@@ -126,12 +126,17 @@ struct gc0310_device {
        struct media_pad pad;
        struct v4l2_mbus_framefmt format;
        struct mutex input_lock;
-       struct v4l2_ctrl_handler ctrl_handler;
 
        struct camera_sensor_platform_data *platform_data;
        struct gc0310_resolution *res;
        u8 type;
        bool power_on;
+
+       struct gc0310_ctrls {
+               struct v4l2_ctrl_handler handler;
+               struct v4l2_ctrl *exposure;
+               struct v4l2_ctrl *gain;
+       } ctrls;
 };
 
 /**