Re: [PATCH 08/23] media: i2c: imx258: Add support for 24MHz clock

Luigi311
2024-03-28T23:08:31Z

On 3/28/24 11:55, Luigi311 wrote:
> On 3/28/24 02:09, Sakari Ailus wrote:
>> Hi Luigi311,
>>
>> Thank you for the patchset.
>>
>> On Wed, Mar 27, 2024 at 05:16:54PM -0600, git@luigi311.com wrote:
>>> From: Dave Stevenson <dave.stevenson@raspberrypi.com>
>>>
>>> There's no reason why only a clock of 19.2MHz is supported.
>>> Indeed this isn't even a frequency listed in the datasheet.
>>>
>>> Add support for 24MHz as well.
>>> The PLL settings result in slightly different link frequencies,
>>> so parameterise those.
>>>
>>> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
>>> Signed-off-by: Luigi311 <git@luigi311.com>
>>
>> Is Luigi311 your real name? As per
>> Documentation/process/submitting-patches.rst, anonymous (or pseudonym I'd
>> say as well) contributions are not an option.
>
> Luigi311 is not my real name but it would be a lot easier to find me if
> it was. My real name is Luis Garcia which is a super common name so its
> actually way easier to find me and all my work using my online name of
> Luigi311. I can go ahead and swap over to Luis Garcia if required but a
> name like that would provide no value in contacting/finding me since I'm
> not famous like all the other Luis Garcia's that appear on google.
>
>>
>>> ---
>>> drivers/media/i2c/imx258.c | 133 +++++++++++++++++++++++++++++--------
>>> 1 file changed, 107 insertions(+), 26 deletions(-)
>>>
>>> diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c
>>> index 351add1bc5d5..6ee7de079454 100644
>>> --- a/drivers/media/i2c/imx258.c
>>> +++ b/drivers/media/i2c/imx258.c
>>> @@ -76,9 +76,6 @@
>>> #define REG_CONFIG_MIRROR_FLIP 0x03
>>> #define REG_CONFIG_FLIP_TEST_PATTERN 0x02
>>>
>>> -/* Input clock frequency in Hz */
>>> -#define IMX258_INPUT_CLOCK_FREQ 19200000
>>> -
>>> struct imx258_reg {
>>> u16 address;
>>> u8 val;
>>> @@ -115,7 +112,9 @@ struct imx258_mode {
>>> };
>>>
>>> /* 4208x3120 needs 1267Mbps/lane, 4 lanes */
>>> -static const struct imx258_reg mipi_data_rate_1267mbps[] = {
>>> +static const struct imx258_reg mipi_1267mbps_19_2mhz[] = {
>>> + { 0x0136, 0x13 },
>>> + { 0x0137, 0x33 },
>>> { 0x0301, 0x05 },
>>> { 0x0303, 0x02 },
>>> { 0x0305, 0x03 },
>>> @@ -133,7 +132,29 @@ static const struct imx258_reg mipi_data_rate_1267mbps[] = {
>>> { 0x0823, 0xCC },
>>> };
>>>
>>> -static const struct imx258_reg mipi_data_rate_640mbps[] = {
>>> +static const struct imx258_reg mipi_1272mbps_24mhz[] = {
>>> + { 0x0136, 0x18 },
>>> + { 0x0137, 0x00 },
>>> + { 0x0301, 0x05 },
>>> + { 0x0303, 0x02 },
>>> + { 0x0305, 0x04 },
>>> + { 0x0306, 0x00 },
>>> + { 0x0307, 0xD4 },
>>> + { 0x0309, 0x0A },
>>> + { 0x030B, 0x01 },
>>> + { 0x030D, 0x02 },
>>> + { 0x030E, 0x00 },
>>> + { 0x030F, 0xD8 },
>>> + { 0x0310, 0x00 },
>>> + { 0x0820, 0x13 },
>>> + { 0x0821, 0x4C },
>>> + { 0x0822, 0xCC },
>>> + { 0x0823, 0xCC },
>>> +};
>>> +
>>> +static const struct imx258_reg mipi_640mbps_19_2mhz[] = {
>>> + { 0x0136, 0x13 },
>>> + { 0x0137, 0x33 },
>>> { 0x0301, 0x05 },
>>> { 0x0303, 0x02 },
>>> { 0x0305, 0x03 },
>>> @@ -151,9 +172,27 @@ static const struct imx258_reg mipi_data_rate_640mbps[] = {
>>> { 0x0823, 0x00 },
>>> };
>>>
>>> +static const struct imx258_reg mipi_642mbps_24mhz[] = {
>>> + { 0x0136, 0x18 },
>>> + { 0x0137, 0x00 },
>>> + { 0x0301, 0x05 },
>>> + { 0x0303, 0x02 },
>>> + { 0x0305, 0x04 },
>>> + { 0x0306, 0x00 },
>>> + { 0x0307, 0x6B },
>>> + { 0x0309, 0x0A },
>>> + { 0x030B, 0x01 },
>>> + { 0x030D, 0x02 },
>>> + { 0x030E, 0x00 },
>>> + { 0x030F, 0xD8 },
>>> + { 0x0310, 0x00 },
>>> + { 0x0820, 0x0A },
>>> + { 0x0821, 0x00 },
>>> + { 0x0822, 0x00 },
>>> + { 0x0823, 0x00 },
>>> +};
>>> +
>>> static const struct imx258_reg mode_common_regs[] = {
>>> - { 0x0136, 0x13 },
>>> - { 0x0137, 0x33 },
>>> { 0x3051, 0x00 },
>>> { 0x3052, 0x00 },
>>> { 0x4E21, 0x14 },
>>> @@ -313,10 +352,6 @@ static const char * const imx258_supply_name[] = {
>>>
>>> #define IMX258_NUM_SUPPLIES ARRAY_SIZE(imx258_supply_name)
>>>
>>> -/* Configurations for supported link frequencies */
>>> -#define IMX258_LINK_FREQ_634MHZ 633600000ULL
>>> -#define IMX258_LINK_FREQ_320MHZ 320000000ULL
>>> -
>>> enum {
>>> IMX258_LINK_FREQ_1267MBPS,
>>> IMX258_LINK_FREQ_640MBPS,
>>> @@ -335,25 +370,55 @@ static u64 link_freq_to_pixel_rate(u64 f)
>>> }
>>>
>>> /* Menu items for LINK_FREQ V4L2 control */
>>> -static const s64 link_freq_menu_items[] = {
>>> +/* Configurations for supported link frequencies */
>>> +#define IMX258_LINK_FREQ_634MHZ 633600000ULL
>>> +#define IMX258_LINK_FREQ_320MHZ 320000000ULL
>>> +
>>> +static const s64 link_freq_menu_items_19_2[] = {
>>> IMX258_LINK_FREQ_634MHZ,
>>> IMX258_LINK_FREQ_320MHZ,
>>> };
>>>
>>> +/* Configurations for supported link frequencies */
>>> +#define IMX258_LINK_FREQ_636MHZ 636000000ULL
>>> +#define IMX258_LINK_FREQ_321MHZ 321000000ULL
>>
>> These values aren't used outside the array below and the macro names are
>> imprecise anyway. Could you put the numerical values to the array instead?
>
> Ok I've removed the defines and just threw the values into the array instead.
>
>>
>>> +
>>> +static const s64 link_freq_menu_items_24[] = {
>>> + IMX258_LINK_FREQ_636MHZ,
>>> + IMX258_LINK_FREQ_321MHZ,
>>> +};
>>> +
>>> /* Link frequency configs */
>>> -static const struct imx258_link_freq_config link_freq_configs[] = {
>>> +static const struct imx258_link_freq_config link_freq_configs_19_2[] = {
>>> [IMX258_LINK_FREQ_1267MBPS] = {
>>> .pixels_per_line = IMX258_PPL_DEFAULT,
>>> .reg_list = {
>>> - .num_of_regs = ARRAY_SIZE(mipi_data_rate_1267mbps),
>>> - .regs = mipi_data_rate_1267mbps,
>>> + .num_of_regs = ARRAY_SIZE(mipi_1267mbps_19_2mhz),
>>> + .regs = mipi_1267mbps_19_2mhz,
>>> }
>>> },
>>> [IMX258_LINK_FREQ_640MBPS] = {
>>> .pixels_per_line = IMX258_PPL_DEFAULT,
>>> .reg_list = {
>>> - .num_of_regs = ARRAY_SIZE(mipi_data_rate_640mbps),
>>> - .regs = mipi_data_rate_640mbps,
>>> + .num_of_regs = ARRAY_SIZE(mipi_640mbps_19_2mhz),
>>> + .regs = mipi_640mbps_19_2mhz,
>>> + }
>>> + },
>>> +};
>>> +
>>> +static const struct imx258_link_freq_config link_freq_configs_24[] = {
>>> + [IMX258_LINK_FREQ_1267MBPS] = {
>>> + .pixels_per_line = IMX258_PPL_DEFAULT,
>>> + .reg_list = {
>>> + .num_of_regs = ARRAY_SIZE(mipi_1272mbps_24mhz),
>>> + .regs = mipi_1272mbps_24mhz,
>>> + }
>>> + },
>>> + [IMX258_LINK_FREQ_640MBPS] = {
>>> + .pixels_per_line = IMX258_PPL_DEFAULT,
>>> + .reg_list = {
>>> + .num_of_regs = ARRAY_SIZE(mipi_642mbps_24mhz),
>>> + .regs = mipi_642mbps_24mhz,
>>> }
>>> },
>>> };
>>> @@ -410,6 +475,9 @@ struct imx258 {
>>> /* Current mode */
>>> const struct imx258_mode *cur_mode;
>>>
>>> + const struct imx258_link_freq_config *link_freq_configs;
>>> + const s64 *link_freq_menu_items;
>>> +
>>> /*
>>> * Mutex for serialized access:
>>> * Protect sensor module set pad format and start/stop streaming safely.
>>> @@ -713,7 +781,7 @@ static int imx258_set_pad_format(struct v4l2_subdev *sd,
>>> imx258->cur_mode = mode;
>>> __v4l2_ctrl_s_ctrl(imx258->link_freq, mode->link_freq_index);
>>>
>>> - link_freq = link_freq_menu_items[mode->link_freq_index];
>>> + link_freq = imx258->link_freq_menu_items[mode->link_freq_index];
>>> pixel_rate = link_freq_to_pixel_rate(link_freq);
>>> __v4l2_ctrl_s_ctrl_int64(imx258->pixel_rate, pixel_rate);
>>> /* Update limits and set FPS to default */
>>> @@ -727,7 +795,7 @@ static int imx258_set_pad_format(struct v4l2_subdev *sd,
>>> vblank_def);
>>> __v4l2_ctrl_s_ctrl(imx258->vblank, vblank_def);
>>> h_blank =
>>> - link_freq_configs[mode->link_freq_index].pixels_per_line
>>> + imx258->link_freq_configs[mode->link_freq_index].pixels_per_line
>>> - imx258->cur_mode->width;
>>> __v4l2_ctrl_modify_range(imx258->hblank, h_blank,
>>> h_blank, 1, h_blank);
>>> @@ -747,7 +815,7 @@ static int imx258_start_streaming(struct imx258 *imx258)
>>>
>>> /* Setup PLL */
>>> link_freq_index = imx258->cur_mode->link_freq_index;
>>> - reg_list = &link_freq_configs[link_freq_index].reg_list;
>>> + reg_list = &imx258->link_freq_configs[link_freq_index].reg_list;
>>> ret = imx258_write_regs(imx258, reg_list->regs, reg_list->num_of_regs);
>>> if (ret) {
>>> dev_err(&client->dev, "%s failed to set plls\n", __func__);
>>> @@ -946,9 +1014,9 @@ static int imx258_init_controls(struct imx258 *imx258)
>>> imx258->link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr,
>>> &imx258_ctrl_ops,
>>> V4L2_CID_LINK_FREQ,
>>> - ARRAY_SIZE(link_freq_menu_items) - 1,
>>> + ARRAY_SIZE(link_freq_menu_items_19_2) - 1,
>>> 0,
>>> - link_freq_menu_items);
>>> + imx258->link_freq_menu_items);
>>>
>>> if (imx258->link_freq)
>>> imx258->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
>>> @@ -964,8 +1032,10 @@ static int imx258_init_controls(struct imx258 *imx258)
>>> if (vflip)
>>> vflip->flags |= V4L2_CTRL_FLAG_READ_ONLY;
>>>
>>> - pixel_rate_max = link_freq_to_pixel_rate(link_freq_menu_items[0]);
>>> - pixel_rate_min = link_freq_to_pixel_rate(link_freq_menu_items[1]);
>>> + pixel_rate_max =
>>> + link_freq_to_pixel_rate(imx258->link_freq_menu_items[0]);
>>> + pixel_rate_min =
>>> + link_freq_to_pixel_rate(imx258->link_freq_menu_items[1]);
>>
>> The arrays currently have two entries so this works but it'd nice to have a
>> bit more robust way to handle differences between the two arrays. Could you
>> maintain e.g. the number of entries in the array in a struct field perhaps?
>
> Would it make more sense to do something like default to index 0 and then use
> ARRAY_SIZE to iterate through the array and do a comparison to get the min and
> max size so it would always choose the correct value no matter how many entries
> there are?
>

Actually down the patch series 15/23 set pixel_rate range to the same as the value,
changes the logic and removes those two lines all together

>>
>>> /* By default, PIXEL_RATE is read only */
>>> imx258->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops,
>>> V4L2_CID_PIXEL_RATE,
>>> @@ -1086,8 +1156,19 @@ static int imx258_probe(struct i2c_client *client)
>>> } else {
>>> val = clk_get_rate(imx258->clk);
>>> }
>>> - if (val != IMX258_INPUT_CLOCK_FREQ) {
>>> - dev_err(&client->dev, "input clock frequency not supported\n");
>>> +
>>> + switch (val) {
>>> + case 19200000:
>>> + imx258->link_freq_configs = link_freq_configs_19_2;
>>> + imx258->link_freq_menu_items = link_freq_menu_items_19_2;
>>> + break;
>>> + case 24000000:
>>> + imx258->link_freq_configs = link_freq_configs_24;
>>> + imx258->link_freq_menu_items = link_freq_menu_items_24;
>>> + break;
>>> + default:
>>> + dev_err(&client->dev, "input clock frequency of %u not supported\n",
>>> + val);
>>> return -EINVAL;
>>> }
>>>
>>
>