diff mbox series

[1/4] media: i2c: imx214: Explain some magic numbers

Message ID 20231023-imx214-v1-1-b33f1bbd1fcf@apitzsch.eu
State Superseded
Headers show
Series media: i2c: imx214: Extend with sensor size and firmware information | expand

Commit Message

André Apitzsch Oct. 23, 2023, 9:47 p.m. UTC 
Code refinement, no functional changes.

Signed-off-by: André Apitzsch <git@apitzsch.eu>
---
 drivers/media/i2c/imx214.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

Comments

André Apitzsch Oct. 24, 2023, 7:30 a.m. UTC | #1 
Am Montag, dem 23.10.2023 um 23:44 +0100 schrieb Kieran Bingham:
> Quoting André Apitzsch (2023-10-23 22:47:50)
> > Code refinement, no functional changes.
> > 
> > Signed-off-by: André Apitzsch <git@apitzsch.eu>
> > ---
> >  drivers/media/i2c/imx214.c | 24 +++++++++++++++++++-----
> >  1 file changed, 19 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/imx214.c
> > b/drivers/media/i2c/imx214.c
> > index 4f77ea02cc27..9218c149d4c8 100644
> > --- a/drivers/media/i2c/imx214.c
> > +++ b/drivers/media/i2c/imx214.c
> > @@ -19,12 +19,23 @@
> >  #include <media/v4l2-fwnode.h>
> >  #include <media/v4l2-subdev.h>
> >  
> > +#define IMX214_REG_MODE_SELECT         0x0100
> > +#define IMX214_MODE_STANDBY            0x00
> > +#define IMX214_MODE_STREAMING          0x01
> > +
> >  #define IMX214_DEFAULT_CLK_FREQ        24000000
> >  #define IMX214_DEFAULT_LINK_FREQ 480000000
> >  #define IMX214_DEFAULT_PIXEL_RATE ((IMX214_DEFAULT_LINK_FREQ *
> > 8LL) / 10)
> >  #define IMX214_FPS 30
> >  #define IMX214_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
> >  
> > +/* Exposure control */
> > +#define IMX214_REG_EXPOSURE            0x0202
> > +#define IMX214_EXPOSURE_MIN            0
> > +#define IMX214_EXPOSURE_MAX            3184
> > +#define IMX214_EXPOSURE_STEP           1
> > +#define IMX214_EXPOSURE_DEFAULT                0x0c70
> 
> I like this change, and I see that 0x0c70 was directly moved here
> from
> the code below. But could we replace 0xc70 here with 3184 please so
> that
> it's /far/ clearer that the Exposure Default == Exposure Max which is
> otherwise hidden?
> 
Hi Kieran,

I can do that. But I propose to replace 3184 with 0x0c70 instead.
Because that matches the entries used in the reg_8 lists
mode_4096x2304[] and mode_1920x1080[].

	{0x0202, 0x0C},
	{0x0203, 0x70}, 

What do you think?

Regards,
André

> --
> Regards
> 
> Kieran
>
Kieran Bingham Oct. 24, 2023, 12:52 p.m. UTC | #2 
Quoting André Apitzsch (2023-10-24 08:30:01)
> Am Montag, dem 23.10.2023 um 23:44 +0100 schrieb Kieran Bingham:
> > Quoting André Apitzsch (2023-10-23 22:47:50)
> > > Code refinement, no functional changes.
> > > 
> > > Signed-off-by: André Apitzsch <git@apitzsch.eu>
> > > ---
> > >  drivers/media/i2c/imx214.c | 24 +++++++++++++++++++-----
> > >  1 file changed, 19 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/media/i2c/imx214.c
> > > b/drivers/media/i2c/imx214.c
> > > index 4f77ea02cc27..9218c149d4c8 100644
> > > --- a/drivers/media/i2c/imx214.c
> > > +++ b/drivers/media/i2c/imx214.c
> > > @@ -19,12 +19,23 @@
> > >  #include <media/v4l2-fwnode.h>
> > >  #include <media/v4l2-subdev.h>
> > >  
> > > +#define IMX214_REG_MODE_SELECT         0x0100
> > > +#define IMX214_MODE_STANDBY            0x00
> > > +#define IMX214_MODE_STREAMING          0x01
> > > +
> > >  #define IMX214_DEFAULT_CLK_FREQ        24000000
> > >  #define IMX214_DEFAULT_LINK_FREQ 480000000
> > >  #define IMX214_DEFAULT_PIXEL_RATE ((IMX214_DEFAULT_LINK_FREQ *
> > > 8LL) / 10)
> > >  #define IMX214_FPS 30
> > >  #define IMX214_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
> > >  
> > > +/* Exposure control */
> > > +#define IMX214_REG_EXPOSURE            0x0202
> > > +#define IMX214_EXPOSURE_MIN            0
> > > +#define IMX214_EXPOSURE_MAX            3184
> > > +#define IMX214_EXPOSURE_STEP           1
> > > +#define IMX214_EXPOSURE_DEFAULT                0x0c70
> > 
> > I like this change, and I see that 0x0c70 was directly moved here
> > from
> > the code below. But could we replace 0xc70 here with 3184 please so
> > that
> > it's /far/ clearer that the Exposure Default == Exposure Max which is
> > otherwise hidden?
> > 
> Hi Kieran,
> 
> I can do that. But I propose to replace 3184 with 0x0c70 instead.
> Because that matches the entries used in the reg_8 lists
> mode_4096x2304[] and mode_1920x1080[].
> 
>         {0x0202, 0x0C},
>         {0x0203, 0x70}, 
> 
> What do you think?

I think exposure values are easier to read as integers than hex values.

This is the 'Coarse Integration Time' register with a unit of 'lines'.

If you have lots of time, or wish to delve deeper - we could talk about
splitting out those register tables to use CCI and/or more readable
functions ;-)

Do you have the datasheet for this sensor - or are you just working from
the information within this driver?

What device are you using to test this driver?

--
Kieran

> Regards,
> André
André Apitzsch Oct. 25, 2023, 9:40 p.m. UTC | #3 
Am Dienstag, dem 24.10.2023 um 13:52 +0100 schrieb Kieran Bingham:
> Quoting André Apitzsch (2023-10-24 08:30:01)
> > Am Montag, dem 23.10.2023 um 23:44 +0100 schrieb Kieran Bingham:
> > > Quoting André Apitzsch (2023-10-23 22:47:50)
> > > > Code refinement, no functional changes.
> > > > 
> > > > Signed-off-by: André Apitzsch <git@apitzsch.eu>
> > > > ---
> > > >  drivers/media/i2c/imx214.c | 24 +++++++++++++++++++-----
> > > >  1 file changed, 19 insertions(+), 5 deletions(-)
> > > > 
> > > > diff --git a/drivers/media/i2c/imx214.c
> > > > b/drivers/media/i2c/imx214.c
> > > > index 4f77ea02cc27..9218c149d4c8 100644
> > > > --- a/drivers/media/i2c/imx214.c
> > > > +++ b/drivers/media/i2c/imx214.c
> > > > @@ -19,12 +19,23 @@
> > > >  #include <media/v4l2-fwnode.h>
> > > >  #include <media/v4l2-subdev.h>
> > > >  
> > > > +#define IMX214_REG_MODE_SELECT         0x0100
> > > > +#define IMX214_MODE_STANDBY            0x00
> > > > +#define IMX214_MODE_STREAMING          0x01
> > > > +
> > > >  #define IMX214_DEFAULT_CLK_FREQ        24000000
> > > >  #define IMX214_DEFAULT_LINK_FREQ 480000000
> > > >  #define IMX214_DEFAULT_PIXEL_RATE ((IMX214_DEFAULT_LINK_FREQ *
> > > > 8LL) / 10)
> > > >  #define IMX214_FPS 30
> > > >  #define IMX214_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
> > > >  
> > > > +/* Exposure control */
> > > > +#define IMX214_REG_EXPOSURE            0x0202
> > > > +#define IMX214_EXPOSURE_MIN            0
> > > > +#define IMX214_EXPOSURE_MAX            3184
> > > > +#define IMX214_EXPOSURE_STEP           1
> > > > +#define IMX214_EXPOSURE_DEFAULT                0x0c70
> > > 
> > > I like this change, and I see that 0x0c70 was directly moved here
> > > from
> > > the code below. But could we replace 0xc70 here with 3184 please
> > > so
> > > that
> > > it's /far/ clearer that the Exposure Default == Exposure Max
> > > which is
> > > otherwise hidden?
> > > 
> > Hi Kieran,
> > 
> > I can do that. But I propose to replace 3184 with 0x0c70 instead.
> > Because that matches the entries used in the reg_8 lists
> > mode_4096x2304[] and mode_1920x1080[].
> > 
> >         {0x0202, 0x0C},
> >         {0x0203, 0x70}, 
> > 
> > What do you think?
> 
> I think exposure values are easier to read as integers than hex
> values.
Okay, integer it is.

> 
> This is the 'Coarse Integration Time' register with a unit of
> 'lines'.
> 
> If you have lots of time, or wish to delve deeper - we could talk
> about splitting out those register tables to use CCI and/or more
> readable functions ;-)

I will consider it.

> 
> Do you have the datasheet for this sensor - or are you just working
> from the information within this driver?

I don't have the datasheet, yet (maybe somebody could provide it), so I
have to work with the information within this driver and downstream
implementations, like the one by nvidia [1].

> 
> What device are you using to test this driver?
> 
The sensor is part of my mobile, BQ Aquaris M5 (Longcheer L9100).

Best regards,
André

[1] https://github.com/InES-HPMM/linux-l4t/blob/9150157d2b1f73aefe01e9a07e3b062a45d57247/drivers/media/i2c/imx214_mode_tbls.h

> --
> Kieran
> 
> > Regards,
> > André
Ricardo Ribalda Delgado Oct. 27, 2023, 12:19 p.m. UTC | #4 
Hi André

Thanks for your patch!

I usually do not care about creating a define for something that I use
only once... but if you think this is more clear, let it be :)



On Mon, Oct 23, 2023 at 11:49 PM André Apitzsch <git@apitzsch.eu> wrote:
>
> Code refinement, no functional changes.
>
> Signed-off-by: André Apitzsch <git@apitzsch.eu>

Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/i2c/imx214.c | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/i2c/imx214.c b/drivers/media/i2c/imx214.c
> index 4f77ea02cc27..9218c149d4c8 100644
> --- a/drivers/media/i2c/imx214.c
> +++ b/drivers/media/i2c/imx214.c
> @@ -19,12 +19,23 @@
>  #include <media/v4l2-fwnode.h>
>  #include <media/v4l2-subdev.h>
>
> +#define IMX214_REG_MODE_SELECT         0x0100
> +#define IMX214_MODE_STANDBY            0x00
> +#define IMX214_MODE_STREAMING          0x01
> +
>  #define IMX214_DEFAULT_CLK_FREQ        24000000
>  #define IMX214_DEFAULT_LINK_FREQ 480000000
>  #define IMX214_DEFAULT_PIXEL_RATE ((IMX214_DEFAULT_LINK_FREQ * 8LL) / 10)
>  #define IMX214_FPS 30
>  #define IMX214_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
>
> +/* Exposure control */
> +#define IMX214_REG_EXPOSURE            0x0202
> +#define IMX214_EXPOSURE_MIN            0
> +#define IMX214_EXPOSURE_MAX            3184
> +#define IMX214_EXPOSURE_STEP           1
> +#define IMX214_EXPOSURE_DEFAULT                0x0c70
> +
>  static const char * const imx214_supply_name[] = {
>         "vdda",
>         "vddd",
> @@ -665,7 +676,7 @@ static int imx214_set_ctrl(struct v4l2_ctrl *ctrl)
>         case V4L2_CID_EXPOSURE:
>                 vals[1] = ctrl->val;
>                 vals[0] = ctrl->val >> 8;
> -               ret = regmap_bulk_write(imx214->regmap, 0x202, vals, 2);
> +               ret = regmap_bulk_write(imx214->regmap, IMX214_REG_EXPOSURE, vals, 2);
>                 if (ret < 0)
>                         dev_err(imx214->dev, "Error %d\n", ret);
>                 ret = 0;
> @@ -743,7 +754,7 @@ static int imx214_start_streaming(struct imx214 *imx214)
>                 dev_err(imx214->dev, "could not sync v4l2 controls\n");
>                 goto error;
>         }
> -       ret = regmap_write(imx214->regmap, 0x100, 1);
> +       ret = regmap_write(imx214->regmap, IMX214_REG_MODE_SELECT, IMX214_MODE_STREAMING);
>         if (ret < 0) {
>                 dev_err(imx214->dev, "could not sent start table %d\n", ret);
>                 goto error;
> @@ -761,7 +772,7 @@ static int imx214_stop_streaming(struct imx214 *imx214)
>  {
>         int ret;
>
> -       ret = regmap_write(imx214->regmap, 0x100, 0);
> +       ret = regmap_write(imx214->regmap, IMX214_REG_MODE_SELECT, IMX214_MODE_STANDBY);
>         if (ret < 0)
>                 dev_err(imx214->dev, "could not sent stop table %d\n",  ret);
>
> @@ -991,9 +1002,12 @@ static int imx214_probe(struct i2c_client *client)
>          *
>          * Yours sincerely, Ricardo.
>          */
> -       imx214->exposure = v4l2_ctrl_new_std(&imx214->ctrls, &imx214_ctrl_ops,
> +       imx214->exposure = v4l2_ctrl_new_std(ctrl_hdlr, &imx214_ctrl_ops,
>                                              V4L2_CID_EXPOSURE,
> -                                            0, 3184, 1, 0x0c70);
> +                                            IMX214_EXPOSURE_MIN,
> +                                            IMX214_EXPOSURE_MAX,
> +                                            IMX214_EXPOSURE_STEP,
> +                                            IMX214_EXPOSURE_DEFAULT);
>
>         imx214->unit_size = v4l2_ctrl_new_std_compound(&imx214->ctrls,
>                                 NULL,
>
> --
> 2.42.0
>
diff mbox series

Patch

diff --git a/drivers/media/i2c/imx214.c b/drivers/media/i2c/imx214.c
index 4f77ea02cc27..9218c149d4c8 100644
--- a/drivers/media/i2c/imx214.c
+++ b/drivers/media/i2c/imx214.c
@@ -19,12 +19,23 @@ 
 #include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
+#define IMX214_REG_MODE_SELECT		0x0100
+#define IMX214_MODE_STANDBY		0x00
+#define IMX214_MODE_STREAMING		0x01
+
 #define IMX214_DEFAULT_CLK_FREQ	24000000
 #define IMX214_DEFAULT_LINK_FREQ 480000000
 #define IMX214_DEFAULT_PIXEL_RATE ((IMX214_DEFAULT_LINK_FREQ * 8LL) / 10)
 #define IMX214_FPS 30
 #define IMX214_MBUS_CODE MEDIA_BUS_FMT_SRGGB10_1X10
 
+/* Exposure control */
+#define IMX214_REG_EXPOSURE		0x0202
+#define IMX214_EXPOSURE_MIN		0
+#define IMX214_EXPOSURE_MAX		3184
+#define IMX214_EXPOSURE_STEP		1
+#define IMX214_EXPOSURE_DEFAULT		0x0c70
+
 static const char * const imx214_supply_name[] = {
 	"vdda",
 	"vddd",
@@ -665,7 +676,7 @@  static int imx214_set_ctrl(struct v4l2_ctrl *ctrl)
 	case V4L2_CID_EXPOSURE:
 		vals[1] = ctrl->val;
 		vals[0] = ctrl->val >> 8;
-		ret = regmap_bulk_write(imx214->regmap, 0x202, vals, 2);
+		ret = regmap_bulk_write(imx214->regmap, IMX214_REG_EXPOSURE, vals, 2);
 		if (ret < 0)
 			dev_err(imx214->dev, "Error %d\n", ret);
 		ret = 0;
@@ -743,7 +754,7 @@  static int imx214_start_streaming(struct imx214 *imx214)
 		dev_err(imx214->dev, "could not sync v4l2 controls\n");
 		goto error;
 	}
-	ret = regmap_write(imx214->regmap, 0x100, 1);
+	ret = regmap_write(imx214->regmap, IMX214_REG_MODE_SELECT, IMX214_MODE_STREAMING);
 	if (ret < 0) {
 		dev_err(imx214->dev, "could not sent start table %d\n", ret);
 		goto error;
@@ -761,7 +772,7 @@  static int imx214_stop_streaming(struct imx214 *imx214)
 {
 	int ret;
 
-	ret = regmap_write(imx214->regmap, 0x100, 0);
+	ret = regmap_write(imx214->regmap, IMX214_REG_MODE_SELECT, IMX214_MODE_STANDBY);
 	if (ret < 0)
 		dev_err(imx214->dev, "could not sent stop table %d\n",	ret);
 
@@ -991,9 +1002,12 @@  static int imx214_probe(struct i2c_client *client)
 	 *
 	 * Yours sincerely, Ricardo.
 	 */
-	imx214->exposure = v4l2_ctrl_new_std(&imx214->ctrls, &imx214_ctrl_ops,
+	imx214->exposure = v4l2_ctrl_new_std(ctrl_hdlr, &imx214_ctrl_ops,
 					     V4L2_CID_EXPOSURE,
-					     0, 3184, 1, 0x0c70);
+					     IMX214_EXPOSURE_MIN,
+					     IMX214_EXPOSURE_MAX,
+					     IMX214_EXPOSURE_STEP,
+					     IMX214_EXPOSURE_DEFAULT);
 
 	imx214->unit_size = v4l2_ctrl_new_std_compound(&imx214->ctrls,
 				NULL,