Re: [PATCH 06/28] media: ti-vpe: cal: use v4l2_get_link_freq

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

Hi Tomi,

Thank you for the patch.

On Mon, Apr 12, 2021 at 02:34:35PM +0300, Tomi Valkeinen wrote:
> CAL driver uses V4L2_CID_PIXEL_RATE to get the required pixel rate, and
> then changes that value to link rate before configuring the registers.
> 
> Rewrite the code to use v4l2_get_link_freq(), which simplifies the code
> as we get the link rate directly, and it also adds support for
> V4L2_CID_LINK_FREQ.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/media/platform/ti-vpe/cal-camerarx.c | 52 +++++++-------------
>  1 file changed, 19 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/media/platform/ti-vpe/cal-camerarx.c b/drivers/media/platform/ti-vpe/cal-camerarx.c
> index 603405824738..974fcbb19547 100644
> --- a/drivers/media/platform/ti-vpe/cal-camerarx.c
> +++ b/drivers/media/platform/ti-vpe/cal-camerarx.c
> @@ -45,22 +45,23 @@ static inline void camerarx_write(struct cal_camerarx *phy, u32 offset, u32 val)
>   * ------------------------------------------------------------------
>   */
>  
> -static s64 cal_camerarx_get_external_rate(struct cal_camerarx *phy)
> +static s64 cal_camerarx_get_ext_link_freq(struct cal_camerarx *phy)
>  {
> -	struct v4l2_ctrl *ctrl;
> -	s64 rate;
> +	struct v4l2_fwnode_bus_mipi_csi2 *mipi_csi2 = &phy->endpoint.bus.mipi_csi2;
> +	u32 num_lanes = mipi_csi2->num_data_lanes;
> +	u32 bpp = phy->fmtinfo->bpp;
> +	s64 freq;
>  
> -	ctrl = v4l2_ctrl_find(phy->source->ctrl_handler, V4L2_CID_PIXEL_RATE);
> -	if (!ctrl) {
> -		phy_err(phy, "no pixel rate control in subdev: %s\n",
> +	freq = v4l2_get_link_freq(phy->source->ctrl_handler, bpp, 2 * num_lanes);
> +	if (freq < 0) {
> +		phy_err(phy, "failed to get link freq for subdev: %s\n",

I'd write "for subdev %s" or "for subdev '%s'".

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

>  			phy->source->name);
> -		return -EPIPE;
> +		return freq;
>  	}
>  
> -	rate = v4l2_ctrl_g_ctrl_int64(ctrl);
> -	phy_dbg(3, phy, "Source Pixel Rate: %llu\n", rate);
> +	phy_dbg(3, phy, "Source Link Freq: %llu\n", freq);
>  
> -	return rate;
> +	return freq;
>  }
>  
>  static void cal_camerarx_lane_config(struct cal_camerarx *phy)
> @@ -116,34 +117,19 @@ void cal_camerarx_disable(struct cal_camerarx *phy)
>  #define TCLK_MISS	1
>  #define TCLK_SETTLE	14
>  
> -static void cal_camerarx_config(struct cal_camerarx *phy, s64 external_rate)
> +static void cal_camerarx_config(struct cal_camerarx *phy, s64 link_freq)
>  {
>  	unsigned int reg0, reg1;
>  	unsigned int ths_term, ths_settle;
> -	unsigned int csi2_ddrclk_khz;
> -	struct v4l2_fwnode_bus_mipi_csi2 *mipi_csi2 =
> -			&phy->endpoint.bus.mipi_csi2;
> -	u32 num_lanes = mipi_csi2->num_data_lanes;
>  
>  	/* DPHY timing configuration */
>  
> -	/*
> -	 * CSI-2 is DDR and we only count used lanes.
> -	 *
> -	 * csi2_ddrclk_khz = external_rate / 1000
> -	 *		   / (2 * num_lanes) * phy->fmtinfo->bpp;
> -	 */
> -	csi2_ddrclk_khz = div_s64(external_rate * phy->fmtinfo->bpp,
> -				  2 * num_lanes * 1000);
> -
> -	phy_dbg(1, phy, "csi2_ddrclk_khz: %d\n", csi2_ddrclk_khz);
> -
>  	/* THS_TERM: Programmed value = floor(20 ns/DDRClk period) */
> -	ths_term = 20 * csi2_ddrclk_khz / 1000000;
> +	ths_term = div_s64(20 * link_freq, 1000 * 1000 * 1000);
>  	phy_dbg(1, phy, "ths_term: %d (0x%02x)\n", ths_term, ths_term);
>  
>  	/* THS_SETTLE: Programmed value = floor(105 ns/DDRClk period) + 4 */
> -	ths_settle = (105 * csi2_ddrclk_khz / 1000000) + 4;
> +	ths_settle = div_s64(105 * link_freq, 1000 * 1000 * 1000) + 4;
>  	phy_dbg(1, phy, "ths_settle: %d (0x%02x)\n", ths_settle, ths_settle);
>  
>  	reg0 = camerarx_read(phy, CAL_CSI2_PHY_REG0);
> @@ -270,14 +256,14 @@ static void cal_camerarx_ppi_disable(struct cal_camerarx *phy)
>  
>  static int cal_camerarx_start(struct cal_camerarx *phy)
>  {
> -	s64 external_rate;
> +	s64 link_freq;
>  	u32 sscounter;
>  	u32 val;
>  	int ret;
>  
> -	external_rate = cal_camerarx_get_external_rate(phy);
> -	if (external_rate < 0)
> -		return external_rate;
> +	link_freq = cal_camerarx_get_ext_link_freq(phy);
> +	if (link_freq < 0)
> +		return link_freq;
>  
>  	ret = v4l2_subdev_call(phy->source, core, s_power, 1);
>  	if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV) {
> @@ -325,7 +311,7 @@ static int cal_camerarx_start(struct cal_camerarx *phy)
>  	camerarx_read(phy, CAL_CSI2_PHY_REG0);
>  
>  	/* Program the PHY timing parameters. */
> -	cal_camerarx_config(phy, external_rate);
> +	cal_camerarx_config(phy, link_freq);
>  
>  	/*
>  	 *    b. Assert the FORCERXMODE signal.

-- 
Regards,

Laurent Pinchart