diff mbox series

[v2] media: imx258: add vblank control to support more frame rate range

Message ID 1634281530-2238-1-git-send-email-bingbu.cao@intel.com (mailing list archive)
State New, archived
Headers show
Series [v2] media: imx258: add vblank control to support more frame rate range | expand

Commit Message

Bingbu Cao Oct. 15, 2021, 7:05 a.m. UTC 
Current imx258 driver enable the automatic frame length tracking control
by default and did not support VBLANK change, it's always working at 30fps.
However, in reality we need a wider frame rate range from 15 to 30.
This patch disable the automatic frame length tracking control and enable
the v4l2 VBLANK control to allow user changing frame rate per requirement.

Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
---
 drivers/media/i2c/imx258.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)
---
v1->v2: remove a wrong 'break'
---

Comments

Kieran Bingham Oct. 15, 2021, 7:49 p.m. UTC | #1 
Hi Bingbu,

Quoting Bingbu Cao (2021-10-15 08:05:30)
> Current imx258 driver enable the automatic frame length tracking control
> by default and did not support VBLANK change, it's always working at 30fps.
> However, in reality we need a wider frame rate range from 15 to 30.
> This patch disable the automatic frame length tracking control and enable
> the v4l2 VBLANK control to allow user changing frame rate per requirement.
> 
> Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
> ---
>  drivers/media/i2c/imx258.c | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)
> ---
> v1->v2: remove a wrong 'break'
> ---
> diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c
> index 81cdf37216ca..3f46744b1a26 100644
> --- a/drivers/media/i2c/imx258.c
> +++ b/drivers/media/i2c/imx258.c
> @@ -29,6 +29,7 @@
>  #define IMX258_VTS_MAX                 0xffff
>  
>  /*Frame Length Line*/
> +#define IMX258_REG_FLL                 0x0340
>  #define IMX258_FLL_MIN                 0x08a6
>  #define IMX258_FLL_MAX                 0xffff
>  #define IMX258_FLL_STEP                        1
> @@ -241,7 +242,7 @@ static const struct imx258_reg mode_4208x3118_regs[] = {
>         { 0x034D, 0x70 },
>         { 0x034E, 0x0C },
>         { 0x034F, 0x30 },
> -       { 0x0350, 0x01 },
> +       { 0x0350, 0x00 },

The commit message implies that the register 0x0350 controls the
"automatic frame length tracking".

Is it worth adding that register description as a comment at the end of
the line, to help future readers?

> +       { 0x0350, 0x00 }, /* automatic frame length tracking */

Without datasheets, these long register lists are very terse ...

If register names /functions can at least be identified then I suspect
it would help with future maintenance of the code?

Or is it too futile to imagine that these registers might improve in
documentation as time goes on...

--
Kieran


>         { 0x0202, 0x0C },
>         { 0x0203, 0x46 },
>         { 0x0204, 0x00 },
> @@ -360,7 +361,7 @@ static const struct imx258_reg mode_2104_1560_regs[] = {
>         { 0x034D, 0x38 },
>         { 0x034E, 0x06 },
>         { 0x034F, 0x18 },
> -       { 0x0350, 0x01 },
> +       { 0x0350, 0x00 },
>         { 0x0202, 0x06 },
>         { 0x0203, 0x2E },
>         { 0x0204, 0x00 },
> @@ -479,7 +480,7 @@ static const struct imx258_reg mode_1048_780_regs[] = {
>         { 0x034D, 0x18 },
>         { 0x034E, 0x03 },
>         { 0x034F, 0x0C },
> -       { 0x0350, 0x01 },
> +       { 0x0350, 0x00 },
>         { 0x0202, 0x03 },
>         { 0x0203, 0x42 },
>         { 0x0204, 0x00 },
> @@ -753,8 +754,17 @@ static int imx258_set_ctrl(struct v4l2_ctrl *ctrl)
>         struct imx258 *imx258 =
>                 container_of(ctrl->handler, struct imx258, ctrl_handler);
>         struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
> +       s64 max;
>         int ret = 0;
>  
> +       if (ctrl->id == V4L2_CID_VBLANK) {
> +               /* Update max exposure to meet expected vblanking */
> +               max = imx258->cur_mode->height + ctrl->val - 10;
> +               __v4l2_ctrl_modify_range(imx258->exposure,
> +                                        imx258->exposure->minimum,
> +                                        max, imx258->exposure->step, max);
> +       }
> +
>         /*
>          * Applying V4L2 control value only happens
>          * when power is up for streaming
> @@ -773,6 +783,10 @@ static int imx258_set_ctrl(struct v4l2_ctrl *ctrl)
>                                 IMX258_REG_VALUE_16BIT,
>                                 ctrl->val);
>                 break;
> +       case V4L2_CID_VBLANK:
> +               ret = imx258_write_reg(imx258, IMX258_REG_FLL, 2,
> +                                      imx258->cur_mode->height + ctrl->val);
> +               break;
>         case V4L2_CID_DIGITAL_GAIN:
>                 ret = imx258_update_digital_gain(imx258, IMX258_REG_VALUE_16BIT,
>                                 ctrl->val);
> @@ -1189,9 +1203,6 @@ static int imx258_init_controls(struct imx258 *imx258)
>                                 IMX258_VTS_MAX - imx258->cur_mode->height, 1,
>                                 vblank_def);
>  
> -       if (imx258->vblank)
> -               imx258->vblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> -
>         imx258->hblank = v4l2_ctrl_new_std(
>                                 ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_HBLANK,
>                                 IMX258_PPL_DEFAULT - imx258->cur_mode->width,
> -- 
> 2.7.4
>
Bingbu Cao Oct. 18, 2021, 2:33 a.m. UTC | #2 
Hi, Bingham

Thanks for your review.
diff mbox series

Patch

diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c
index 81cdf37216ca..3f46744b1a26 100644
--- a/drivers/media/i2c/imx258.c
+++ b/drivers/media/i2c/imx258.c
@@ -29,6 +29,7 @@ 
 #define IMX258_VTS_MAX			0xffff
 
 /*Frame Length Line*/
+#define IMX258_REG_FLL			0x0340
 #define IMX258_FLL_MIN			0x08a6
 #define IMX258_FLL_MAX			0xffff
 #define IMX258_FLL_STEP			1
@@ -241,7 +242,7 @@  static const struct imx258_reg mode_4208x3118_regs[] = {
 	{ 0x034D, 0x70 },
 	{ 0x034E, 0x0C },
 	{ 0x034F, 0x30 },
-	{ 0x0350, 0x01 },
+	{ 0x0350, 0x00 },
 	{ 0x0202, 0x0C },
 	{ 0x0203, 0x46 },
 	{ 0x0204, 0x00 },
@@ -360,7 +361,7 @@  static const struct imx258_reg mode_2104_1560_regs[] = {
 	{ 0x034D, 0x38 },
 	{ 0x034E, 0x06 },
 	{ 0x034F, 0x18 },
-	{ 0x0350, 0x01 },
+	{ 0x0350, 0x00 },
 	{ 0x0202, 0x06 },
 	{ 0x0203, 0x2E },
 	{ 0x0204, 0x00 },
@@ -479,7 +480,7 @@  static const struct imx258_reg mode_1048_780_regs[] = {
 	{ 0x034D, 0x18 },
 	{ 0x034E, 0x03 },
 	{ 0x034F, 0x0C },
-	{ 0x0350, 0x01 },
+	{ 0x0350, 0x00 },
 	{ 0x0202, 0x03 },
 	{ 0x0203, 0x42 },
 	{ 0x0204, 0x00 },
@@ -753,8 +754,17 @@  static int imx258_set_ctrl(struct v4l2_ctrl *ctrl)
 	struct imx258 *imx258 =
 		container_of(ctrl->handler, struct imx258, ctrl_handler);
 	struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
+	s64 max;
 	int ret = 0;
 
+	if (ctrl->id == V4L2_CID_VBLANK) {
+		/* Update max exposure to meet expected vblanking */
+		max = imx258->cur_mode->height + ctrl->val - 10;
+		__v4l2_ctrl_modify_range(imx258->exposure,
+					 imx258->exposure->minimum,
+					 max, imx258->exposure->step, max);
+	}
+
 	/*
 	 * Applying V4L2 control value only happens
 	 * when power is up for streaming
@@ -773,6 +783,10 @@  static int imx258_set_ctrl(struct v4l2_ctrl *ctrl)
 				IMX258_REG_VALUE_16BIT,
 				ctrl->val);
 		break;
+	case V4L2_CID_VBLANK:
+		ret = imx258_write_reg(imx258, IMX258_REG_FLL, 2,
+				       imx258->cur_mode->height + ctrl->val);
+		break;
 	case V4L2_CID_DIGITAL_GAIN:
 		ret = imx258_update_digital_gain(imx258, IMX258_REG_VALUE_16BIT,
 				ctrl->val);
@@ -1189,9 +1203,6 @@  static int imx258_init_controls(struct imx258 *imx258)
 				IMX258_VTS_MAX - imx258->cur_mode->height, 1,
 				vblank_def);
 
-	if (imx258->vblank)
-		imx258->vblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;
-
 	imx258->hblank = v4l2_ctrl_new_std(
 				ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_HBLANK,
 				IMX258_PPL_DEFAULT - imx258->cur_mode->width,