Re: [PATCH v5 04/14] media: cadence: csi2rx: Add external DPHY support
From: Laurent Pinchart
Date: Wed Dec 29 2021 - 23:43:28 EST
On Fri, Dec 24, 2021 at 12:46:05AM +0530, Pratyush Yadav wrote:
> Some platforms like TI's J721E can have the CSI2RX paired with an
> external DPHY. Add support to enable and configure the DPHY using the
> generic PHY framework.
>
> Signed-off-by: Pratyush Yadav <p.yadav@xxxxxx>
>
> ---
>
> Changes in v5:
> - Only error out when phy_pm_runtime_get_sync() returns a negative
> value. A positive value can be returned if the phy was already
> resumed.
> - Do not query the source subdev for format. Use the newly added
> internal format instead.
>
> Changes in v4:
> - Drop the call to set PHY submode. It is now being done via compatible
> on the DPHY side.
>
> Changes in v3:
> - Use v4l2_get_link_freq() to calculate pixel clock.
>
> Changes in v2:
> - Use phy_pm_runtime_get_sync() and phy_pm_runtime_put() before making
> calls to set PHY mode, etc. to make sure it is ready.
>
> drivers/media/platform/cadence/cdns-csi2rx.c | 98 ++++++++++++++++++--
> 1 file changed, 88 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index 4a2a5a9d019b..afd4a0da8235 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -30,6 +30,12 @@
> #define CSI2RX_STATIC_CFG_DLANE_MAP(llane, plane) ((plane) << (16 + (llane) * 4))
> #define CSI2RX_STATIC_CFG_LANES_MASK GENMASK(11, 8)
>
> +#define CSI2RX_DPHY_LANE_CTRL_REG 0x40
> +#define CSI2RX_DPHY_CL_RST BIT(16)
> +#define CSI2RX_DPHY_DL_RST(i) BIT((i) + 12)
> +#define CSI2RX_DPHY_CL_EN BIT(4)
> +#define CSI2RX_DPHY_DL_EN(i) BIT(i)
> +
> #define CSI2RX_STREAM_BASE(n) (((n) + 1) * 0x100)
>
> #define CSI2RX_STREAM_CTRL_REG(n) (CSI2RX_STREAM_BASE(n) + 0x000)
> @@ -137,6 +143,57 @@ static void csi2rx_reset(struct csi2rx_priv *csi2rx)
> writel(0, csi2rx->base + CSI2RX_SOFT_RESET_REG);
> }
>
> +static int csi2rx_configure_external_dphy(struct csi2rx_priv *csi2rx)
> +{
> + union phy_configure_opts opts = { };
> + struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
> + const struct csi2rx_fmt *fmt;
> + s64 pixel_clock;
> + int ret;
> + u8 bpp;
> + bool got_pm = true;
> +
> + fmt = csi2rx_get_fmt_by_code(csi2rx->fmt.code);
> + bpp = fmt->bpp;
> +
> + /*
> + * Do not divide by the number of lanes here. That will be done by
> + * phy_mipi_dphy_get_default_config().
> + */
> + pixel_clock = v4l2_get_link_freq(csi2rx->source_subdev->ctrl_handler,
> + 1, 2);
> + if (pixel_clock < 0)
> + return pixel_clock;
> +
> + ret = phy_mipi_dphy_get_default_config(pixel_clock, bpp,
You could use fmt->bpp here and drop the bpp variable.
> + csi2rx->num_lanes, cfg);
> + if (ret)
> + return ret;
> +
> + ret = phy_pm_runtime_get_sync(csi2rx->dphy);
> + if (ret == -ENOTSUPP)
> + got_pm = false;
phy_pm_runtime_put() returns -ENOTSUPP when runtime PM isn't enabled,
without calling pm_runtime_put(). I think you could write here
ret = phy_pm_runtime_get_sync(csi2rx->dphy);
if (ret < 0 && ret != -ENOTSUPP)
return ret;
then drop the got_pm variable, and call phy_pm_runtime_put()
unconditionally below.
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> + else if (ret < 0)
> + return ret;
> +
> + ret = phy_power_on(csi2rx->dphy);
> + if (ret)
> + goto out;
> +
> + ret = phy_configure(csi2rx->dphy, &opts);
> + if (ret) {
> + /* Can't do anything if it fails. Ignore the return value. */
> + phy_power_off(csi2rx->dphy);
> + goto out;
> + }
> +
> +out:
> + if (got_pm)
> + phy_pm_runtime_put(csi2rx->dphy);
> +
> + return ret;
> +}
> +
> static int csi2rx_start(struct csi2rx_priv *csi2rx)
> {
> unsigned int i;
> @@ -175,6 +232,17 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
> if (ret)
> goto err_disable_pclk;
>
> + /* Enable DPHY clk and data lanes. */
> + if (csi2rx->dphy) {
> + reg = CSI2RX_DPHY_CL_EN | CSI2RX_DPHY_CL_RST;
> + for (i = 0; i < csi2rx->num_lanes; i++) {
> + reg |= CSI2RX_DPHY_DL_EN(csi2rx->lanes[i] - 1);
> + reg |= CSI2RX_DPHY_DL_RST(csi2rx->lanes[i] - 1);
> + }
> +
> + writel(reg, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
> + }
> +
> /*
> * Create a static mapping between the CSI virtual channels
> * and the output stream.
> @@ -205,10 +273,21 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
> if (ret)
> goto err_disable_pixclk;
>
> + if (csi2rx->dphy) {
> + ret = csi2rx_configure_external_dphy(csi2rx);
> + if (ret) {
> + dev_err(csi2rx->dev,
> + "Failed to configure external DPHY: %d\n", ret);
> + goto err_disable_sysclk;
> + }
> + }
> +
> clk_disable_unprepare(csi2rx->p_clk);
>
> return 0;
>
> +err_disable_sysclk:
> + clk_disable_unprepare(csi2rx->sys_clk);
> err_disable_pixclk:
> for (; i > 0; i--)
> clk_disable_unprepare(csi2rx->pixel_clk[i - 1]);
> @@ -236,6 +315,13 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx)
>
> if (v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false))
> dev_warn(csi2rx->dev, "Couldn't disable our subdev\n");
> +
> + if (csi2rx->dphy) {
> + writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
> +
> + if (phy_power_off(csi2rx->dphy))
> + dev_warn(csi2rx->dev, "Couldn't power off DPHY\n");
> + }
> }
>
> static int csi2rx_s_stream(struct v4l2_subdev *subdev, int enable)
> @@ -438,15 +524,6 @@ static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
> return PTR_ERR(csi2rx->dphy);
> }
>
> - /*
> - * FIXME: Once we'll have external D-PHY support, the check
> - * will need to be removed.
> - */
> - if (csi2rx->dphy) {
> - dev_err(&pdev->dev, "External D-PHY not supported yet\n");
> - return -EINVAL;
> - }
> -
> ret = clk_prepare_enable(csi2rx->p_clk);
> if (ret) {
> dev_err(&pdev->dev, "Couldn't prepare and enable P clock\n");
> @@ -476,7 +553,7 @@ static int csi2rx_get_resources(struct csi2rx_priv *csi2rx,
> * FIXME: Once we'll have internal D-PHY support, the check
> * will need to be removed.
> */
> - if (csi2rx->has_internal_dphy) {
> + if (!csi2rx->dphy && csi2rx->has_internal_dphy) {
> dev_err(&pdev->dev, "Internal D-PHY not supported yet\n");
> return -EINVAL;
> }
> @@ -601,6 +678,7 @@ static int csi2rx_probe(struct platform_device *pdev)
> dev_info(&pdev->dev,
> "Probed CSI2RX with %u/%u lanes, %u streams, %s D-PHY\n",
> csi2rx->num_lanes, csi2rx->max_lanes, csi2rx->max_streams,
> + csi2rx->dphy ? "external" :
> csi2rx->has_internal_dphy ? "internal" : "no");
>
> return 0;
--
Regards,
Laurent Pinchart