Re: [PATCH v3 2/5] media: i2c: imx214: Prepare for variable clock frequency

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi André,

Thank you for the patch.

On Wed, May 21, 2025 at 09:34:25PM +0200, André Apitzsch via B4 Relay wrote:
> From: André Apitzsch <git@apitzsch.eu>
> 
> Move clock frequency related parameters out of the constant register
> sequences, such that the hard coded external clock frequency can be
> replaced by a variable in the upcoming patches.
> 
> Acked-by: Ricardo Ribalda <ribalda@chromium.org>
> Signed-off-by: André Apitzsch <git@apitzsch.eu>
> ---
>  drivers/media/i2c/imx214.c | 54 ++++++++++++++++++++++++++--------------------
>  1 file changed, 31 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/media/i2c/imx214.c b/drivers/media/i2c/imx214.c
> index 0199195dcb7d12dc2ff253fe3eb77ddbcd0812a9..3aca6ebb02d649c1b7f0b6a6049c1e3aa3d08951 100644
> --- a/drivers/media/i2c/imx214.c
> +++ b/drivers/media/i2c/imx214.c
> @@ -299,16 +299,6 @@ static const struct cci_reg_sequence mode_4096x2304[] = {
>  	{ IMX214_REG_DIG_CROP_WIDTH, 4096 },
>  	{ IMX214_REG_DIG_CROP_HEIGHT, 2304 },
>  
> -	{ IMX214_REG_VTPXCK_DIV, 5 },
> -	{ IMX214_REG_VTSYCK_DIV, 2 },
> -	{ IMX214_REG_PREPLLCK_VT_DIV, 3 },
> -	{ IMX214_REG_PLL_VT_MPY, 150 },
> -	{ IMX214_REG_OPPXCK_DIV, 10 },
> -	{ IMX214_REG_OPSYCK_DIV, 1 },
> -	{ IMX214_REG_PLL_MULT_DRIV, IMX214_PLL_SINGLE },
> -
> -	{ IMX214_REG_REQ_LINK_BIT_RATE, IMX214_LINK_BIT_RATE_MBPS(4800) },
> -
>  	{ CCI_REG8(0x3A03), 0x09 },
>  	{ CCI_REG8(0x3A04), 0x50 },
>  	{ CCI_REG8(0x3A05), 0x01 },
> @@ -362,16 +352,6 @@ static const struct cci_reg_sequence mode_1920x1080[] = {
>  	{ IMX214_REG_DIG_CROP_WIDTH, 1920 },
>  	{ IMX214_REG_DIG_CROP_HEIGHT, 1080 },
>  
> -	{ IMX214_REG_VTPXCK_DIV, 5 },
> -	{ IMX214_REG_VTSYCK_DIV, 2 },
> -	{ IMX214_REG_PREPLLCK_VT_DIV, 3 },
> -	{ IMX214_REG_PLL_VT_MPY, 150 },
> -	{ IMX214_REG_OPPXCK_DIV, 10 },
> -	{ IMX214_REG_OPSYCK_DIV, 1 },
> -	{ IMX214_REG_PLL_MULT_DRIV, IMX214_PLL_SINGLE },
> -
> -	{ IMX214_REG_REQ_LINK_BIT_RATE, IMX214_LINK_BIT_RATE_MBPS(4800) },
> -
>  	{ CCI_REG8(0x3A03), 0x04 },
>  	{ CCI_REG8(0x3A04), 0xF8 },
>  	{ CCI_REG8(0x3A05), 0x02 },
> @@ -405,9 +385,6 @@ static const struct cci_reg_sequence mode_table_common[] = {
>  	/* ATR setting */
>  	{ IMX214_REG_ATR_FAST_MOVE, 2 },
>  
> -	/* external clock setting */
> -	{ IMX214_REG_EXCK_FREQ, IMX214_EXCK_FREQ(IMX214_DEFAULT_CLK_FREQ / 1000000) },
> -
>  	/* global setting */
>  	/* basic config */
>  	{ IMX214_REG_MASK_CORR_FRAMES, IMX214_CORR_FRAMES_MASK },
> @@ -777,6 +754,24 @@ static int imx214_entity_init_state(struct v4l2_subdev *subdev,
>  	return 0;
>  }
>  
> +static int imx214_configure_pll(struct imx214 *imx214)
> +{
> +	int ret = 0;
> +
> +	cci_write(imx214->regmap, IMX214_REG_VTPXCK_DIV, 5, &ret);
> +	cci_write(imx214->regmap, IMX214_REG_VTSYCK_DIV, 2, &ret);
> +	cci_write(imx214->regmap, IMX214_REG_PREPLLCK_VT_DIV, 3, &ret);
> +	cci_write(imx214->regmap, IMX214_REG_PLL_VT_MPY, 150, &ret);
> +	cci_write(imx214->regmap, IMX214_REG_OPPXCK_DIV, 10, &ret);
> +	cci_write(imx214->regmap, IMX214_REG_OPSYCK_DIV, 1, &ret);
> +	cci_write(imx214->regmap, IMX214_REG_PLL_MULT_DRIV,
> +		  IMX214_PLL_SINGLE, &ret);
> +	cci_write(imx214->regmap, IMX214_REG_EXCK_FREQ,
> +		  IMX214_EXCK_FREQ(IMX214_DEFAULT_CLK_FREQ / 1000000), &ret);
> +
> +	return ret;
> +}
> +
>  static int imx214_update_digital_gain(struct imx214 *imx214, u32 val)
>  {
>  	int ret = 0;
> @@ -1020,6 +1015,19 @@ static int imx214_start_streaming(struct imx214 *imx214)
>  		return ret;
>  	}
>  
> +	ret = imx214_configure_pll(imx214);
> +	if (ret) {
> +		dev_err(imx214->dev, "failed to configure PLL %d\n", ret);

		dev_err(imx214->dev, "failed to configure PLL: %d\n", ret);

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +		return ret;
> +	}
> +
> +	ret = cci_write(imx214->regmap, IMX214_REG_REQ_LINK_BIT_RATE,
> +			IMX214_LINK_BIT_RATE_MBPS(4800), NULL);
> +	if (ret) {
> +		dev_err(imx214->dev, "failed to configure link bit rate\n");
> +		return ret;
> +	}
> +
>  	ret = cci_write(imx214->regmap, IMX214_REG_CSI_LANE_MODE,
>  			IMX214_CSI_4_LANE_MODE, NULL);
>  	if (ret) {

-- 
Regards,

Laurent Pinchart