Re: [PATCH v4 02/21] media: i2c: imx355: Add support for 24 MHz external clock
From: Richard Acayan
Date: Wed Jul 15 2026 - 15:47:59 EST
On Wed, Jul 15, 2026 at 12:43:15PM +0100, Dave Stevenson wrote:
> From: David Heidelberg <david@xxxxxxx>
>
> The IMX355 sensor supports multiple external clock frequencies,
> including 19.2 MHz and 24 MHz. The driver currently supports only
> fixed 19.2 MHz input clock.
>
> Refactor the clock handling to make the PLL configuration dependent
> on the external clock frequency and add support for 24 MHz. Introduce
> a table of clock parameter sets and program the corresponding EXTCLK
> frequency and PLL multipliers to maintain consistent internal VCO
> frequencies across supported inputs.
>
> The PLL settings are adjusted so that OP VCO remains at 720 MHz
>
> This preserves existing timing characteristics while allowing systems
> using a 24 MHz clock to operate correctly.
>
> No functional change for existing 19.2 MHz users.
>
> Assisted-by: Claude:claude-opus-4-6
> Signed-off-by: David Heidelberg <david@xxxxxxx>
> Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
> ---
> drivers/media/i2c/imx355.c | 77 +++++++++++++++++++++++++++-------------------
> 1 file changed, 45 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/media/i2c/imx355.c b/drivers/media/i2c/imx355.c
> index ac59908f57aa..a6ee7532018f 100644
> --- a/drivers/media/i2c/imx355.c
> +++ b/drivers/media/i2c/imx355.c
(snip)
> @@ -1749,7 +1756,13 @@ static int imx355_probe(struct i2c_client *client)
> "failed to get clock\n");
>
> freq = clk_get_rate(imx355->clk);
> - if (freq != IMX355_EXT_CLK)
> + for (unsigned int i = 0; i < ARRAY_SIZE(imx355_clk_params); i++) {
Did we start allowing variable declarations mixed with code?