media: i2c: ov7251: Limit exposure based on VTS

The maximum exposure is dictated by VTS, so compute it rather
than having the value in the mode table.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

diff --git a/drivers/media/i2c/ov7251.c b/drivers/media/i2c/ov7251.c
index 6118c23..54eee4f 100644 (file)
--- a/drivers/media/i2c/ov7251.c
+++ b/drivers/media/i2c/ov7251.c
@@ -37,6 +37,8 @@
 #define OV7251_AEC_EXPO_2              0x3502
 #define OV7251_AEC_AGC_ADJ_0           0x350a
 #define OV7251_AEC_AGC_ADJ_1           0x350b
+/* Exposure must be at least 20 lines shorter than VTS */
+#define OV7251_EXPOSURE_OFFSET         20
  /* HTS is registers 0x380c and 0x380d */
 #define OV7251_HTS                     0x3a0
 #define OV7251_VTS_HIGH                        0x380e
@@ -82,7 +84,6 @@ struct ov7251_mode_info {
        u32 height;
        const struct reg_value *data;
        u32 data_size;
-       u16 exposure_max;
        u16 exposure_def;
        u16 vts;
        struct v4l2_fract timeperframe;
@@ -348,7 +349,6 @@ static const struct ov7251_mode_info ov7251_mode_info_data[] = {
                .height = 480,
                .data = ov7251_setting_vga,
                .data_size = ARRAY_SIZE(ov7251_setting_vga),
-               .exposure_max = 1704,
                .exposure_def = 504,
                .vts = 0x6bc,
                .timeperframe = {
@@ -361,7 +361,6 @@ static const struct ov7251_mode_info ov7251_mode_info_data[] = {
                .height = 480,
                .data = ov7251_setting_vga,
                .data_size = ARRAY_SIZE(ov7251_setting_vga),
-               .exposure_max = 840,
                .exposure_def = 504,
                .vts = 0x35c,
                .timeperframe = {
@@ -374,7 +373,6 @@ static const struct ov7251_mode_info ov7251_mode_info_data[] = {
                .height = 480,
                .data = ov7251_setting_vga,
                .data_size = ARRAY_SIZE(ov7251_setting_vga),
-               .exposure_max = 552,
                .exposure_def = 504,
                .vts = 0x23c,
                .timeperframe = {
@@ -915,8 +913,8 @@ static int ov7251_set_format(struct v4l2_subdev *sd,
                                         h_blank, 1, h_blank);
                __v4l2_ctrl_s_ctrl(ov7251->hblank, h_blank);
 
-               ret = __v4l2_ctrl_modify_range(ov7251->exposure,
-                                              1, new_mode->exposure_max,
+               ret = __v4l2_ctrl_modify_range(ov7251->exposure, 1,
+                                              new_mode->vts - OV7251_EXPOSURE_OFFSET,
                                               1, new_mode->exposure_def);
                if (ret < 0)
                        goto exit;
@@ -1092,8 +1090,8 @@ static int ov7251_set_frame_interval(struct v4l2_subdev *subdev,
        new_mode = ov7251_find_mode_by_ival(ov7251, &fi->interval);
 
        if (new_mode != ov7251->current_mode) {
-               ret = __v4l2_ctrl_modify_range(ov7251->exposure,
-                                              1, new_mode->exposure_max,
+               ret = __v4l2_ctrl_modify_range(ov7251->exposure, 1,
+                                              new_mode->vts - OV7251_EXPOSURE_OFFSET,
                                               1, new_mode->exposure_def);
                if (ret < 0)
                        goto exit;