Re: [PATCH v3 19/25] media: i2c: imx258: Change register settings for variants of the sensor

Sakari Ailus
2024-04-05T10:59:42Z

Hi Luis, Dave,

On Thu, Apr 04, 2024 at 04:44:05PM -0600, Luigi311 wrote:
> On 4/3/24 10:18, Sakari Ailus wrote:
> > Hi Luis, Dave,
> >
> > On Wed, Apr 03, 2024 at 09:03:48AM -0600, git@luigi311.com wrote:
> >> From: Dave Stevenson <dave.stevenson@raspberrypi.com>
> >>
> >> Sony have advised that there are variants of the IMX258 sensor which
> >> require slightly different register configuration to the mainline
> >> imx258 driver defaults.
> >>
> >> There is no available run-time detection for the variant, so add
> >> configuration via the DT compatible string.
> >>
> >> The Vision Components imx258 module supports PDAF, so add the
> >> register differences for that variant
> >>
> >> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
> >> Signed-off-by: Luis Garcia <git@luigi311.com>
> >> ---
> >> drivers/media/i2c/imx258.c | 48 ++++++++++++++++++++++++++++++++++----
> >> 1 file changed, 44 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c
> >> index 775d957c9b87..fa48da212037 100644
> >> --- a/drivers/media/i2c/imx258.c
> >> +++ b/drivers/media/i2c/imx258.c
> >> @@ -6,6 +6,7 @@
> >> #include <linux/delay.h>
> >> #include <linux/i2c.h>
> >> #include <linux/module.h>
> >> +#include <linux/of_device.h>
> >> #include <linux/pm_runtime.h>
> >> #include <linux/regulator/consumer.h>
> >> #include <media/v4l2-ctrls.h>
> >> @@ -321,8 +322,6 @@ static const struct imx258_reg mipi_642mbps_24mhz_4l[] = {
> >>
> >> static const struct imx258_reg mode_common_regs[] = {
> >> { 0x3051, 0x00 },
> >> - { 0x3052, 0x00 },
> >> - { 0x4E21, 0x14 },
> >> { 0x6B11, 0xCF },
> >> { 0x7FF0, 0x08 },
> >> { 0x7FF1, 0x0F },
> >> @@ -345,7 +344,6 @@ static const struct imx258_reg mode_common_regs[] = {
> >> { 0x7FA8, 0x03 },
> >> { 0x7FA9, 0xFE },
> >> { 0x7B24, 0x81 },
> >> - { 0x7B25, 0x00 },
> >> { 0x6564, 0x07 },
> >> { 0x6B0D, 0x41 },
> >> { 0x653D, 0x04 },
> >> @@ -460,6 +458,33 @@ static const struct imx258_reg mode_1048_780_regs[] = {
> >> { 0x034F, 0x0C },
> >> };
> >>
> >> +struct imx258_variant_cfg {
> >> + const struct imx258_reg *regs;
> >> + unsigned int num_regs;
> >> +};
> >> +
> >> +static const struct imx258_reg imx258_cfg_regs[] = {
> >> + { 0x3052, 0x00 },
> >> + { 0x4E21, 0x14 },
> >> + { 0x7B25, 0x00 },
> >> +};
> >> +
> >> +static const struct imx258_variant_cfg imx258_cfg = {
> >> + .regs = imx258_cfg_regs,
> >> + .num_regs = ARRAY_SIZE(imx258_cfg_regs),
> >> +};
> >> +
> >> +static const struct imx258_reg imx258_pdaf_cfg_regs[] = {
> >> + { 0x3052, 0x01 },
> >> + { 0x4E21, 0x10 },
> >> + { 0x7B25, 0x01 },
> >> +};
> >> +
> >> +static const struct imx258_variant_cfg imx258_pdaf_cfg = {
> >> + .regs = imx258_pdaf_cfg_regs,
> >> + .num_regs = ARRAY_SIZE(imx258_pdaf_cfg_regs),
> >> +};
> >> +
> >> static const char * const imx258_test_pattern_menu[] = {
> >> "Disabled",
> >> "Solid Colour",
> >> @@ -637,6 +662,8 @@ struct imx258 {
> >> struct v4l2_subdev sd;
> >> struct media_pad pad;
> >>
> >> + const struct imx258_variant_cfg *variant_cfg;
> >> +
> >> struct v4l2_ctrl_handler ctrl_handler;
> >> /* V4L2 Controls */
> >> struct v4l2_ctrl *link_freq;
> >> @@ -1104,6 +1131,14 @@ static int imx258_start_streaming(struct imx258 *imx258)
> >> return ret;
> >> }
> >>
> >> + ret = imx258_write_regs(imx258, imx258->variant_cfg->regs,
> >> + imx258->variant_cfg->num_regs);
> >> + if (ret) {
> >> + dev_err(&client->dev, "%s failed to set variant config\n",
> >> + __func__);
> >> + return ret;
> >> + }
> >> +
> >> ret = imx258_write_reg(imx258, IMX258_CLK_BLANK_STOP,
> >> IMX258_REG_VALUE_08BIT,
> >> imx258->csi2_flags & V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK ?
> >> @@ -1492,6 +1527,10 @@ static int imx258_probe(struct i2c_client *client)
> >>
> >> imx258->csi2_flags = ep.bus.mipi_csi2.flags;
> >>
> >> + imx258->variant_cfg = of_device_get_match_data(&client->dev);
> >
> > You'll also need to keep this working for ACPI based systems. I.e. in
> > practice remove "of_" prefix here and add the non-PDAF variant data to the
> > relevant ACPI ID list.
> >
>
> Removing of_ is easy enough and looking at all the other commits that make
> this change in other drivers I dont see anything else being done besides
> adding in the .data section that is down below for both imx258 and pdaf
> versions. Is that what you are referencing or is there some other place
> to add variant data to ACPI ID list?

Speaking of which---are you absolutely certain there are two variants of
this sensor? Many sensors that have a different pixel pattern (PDAF pixels
or a non-Bayer pattern) can produce Bayer data when condigured so. The fact
that you have differing register configuration for the PDAF and non-PDAF
cases suggests this may well be the case.

>
> >> + if (!imx258->variant_cfg)
> >> + imx258->variant_cfg = &imx258_cfg;
> >> +
> >> /* Initialize subdev */
> >> v4l2_i2c_subdev_init(&imx258->sd, client, &imx258_subdev_ops);
> >>
> >> @@ -1579,7 +1618,8 @@ MODULE_DEVICE_TABLE(acpi, imx258_acpi_ids);
> >> #endif
> >>
> >> static const struct of_device_id imx258_dt_ids[] = {
> >> - { .compatible = "sony,imx258" },
> >> + { .compatible = "sony,imx258", .data = &imx258_cfg },
> >> + { .compatible = "sony,imx258-pdaf", .data = &imx258_pdaf_cfg },
> >> { /* sentinel */ }
> >> };
> >> MODULE_DEVICE_TABLE(of, imx258_dt_ids);
> >
>

--
Regards,

Sakari Ailus