Re: [PATCH 05/16] media: cadence: csi2rx: Add external DPHY support
From: Chunfeng Yun
Date: Thu Apr 08 2021 - 04:14:13 EST
On Wed, 2021-04-07 at 00:24 +0530, Pratyush Yadav wrote:
> On 31/03/21 05:24PM, Chunfeng Yun wrote:
> > On Tue, 2021-03-30 at 23:03 +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.
> > >
> > > Get the pixel rate and bpp from the subdev and pass them on to the DPHY
> > > along with the number of lanes. All other settings are left to their
> > > default values.
> > >
> > > Signed-off-by: Pratyush Yadav <p.yadav@xxxxxx>
> > > ---
> > > drivers/media/platform/cadence/cdns-csi2rx.c | 147 +++++++++++++++++--
> > > 1 file changed, 137 insertions(+), 10 deletions(-)
> > >
> > > diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> > > index c68a3eac62cd..31bd80e3f780 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)
> > > @@ -54,6 +60,11 @@ enum csi2rx_pads {
> > > CSI2RX_PAD_MAX,
> > > };
> > >
> > > +struct csi2rx_fmt {
> > > + u32 code;
> > > + u8 bpp;
> > > +};
> > > +
> > > struct csi2rx_priv {
> > > struct device *dev;
> > > unsigned int count;
> > > @@ -85,6 +96,52 @@ struct csi2rx_priv {
> > > int source_pad;
> > > };
> > >
> > > +static const struct csi2rx_fmt formats[] = {
> > > + {
> > > + .code = MEDIA_BUS_FMT_YUYV8_2X8,
> > > + .bpp = 16,
> > > + },
> > > + {
> > > + .code = MEDIA_BUS_FMT_UYVY8_2X8,
> > > + .bpp = 16,
> > > + },
> > > + {
> > > + .code = MEDIA_BUS_FMT_YVYU8_2X8,
> > > + .bpp = 16,
> > > + },
> > > + {
> > > + .code = MEDIA_BUS_FMT_VYUY8_2X8,
> > > + .bpp = 16,
> > > + },
> > > +};
> > > +
> > > +static u8 csi2rx_get_bpp(u32 code)
> > > +{
> > > + int i;
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(formats); i++) {
> > > + if (formats[i].code == code)
> > > + return formats[i].bpp;
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static s64 csi2rx_get_pixel_rate(struct csi2rx_priv *csi2rx)
> > > +{
> > > + struct v4l2_ctrl *ctrl;
> > > +
> > > + ctrl = v4l2_ctrl_find(csi2rx->source_subdev->ctrl_handler,
> > > + V4L2_CID_PIXEL_RATE);
> > > + if (!ctrl) {
> > > + dev_err(csi2rx->dev, "no pixel rate control in subdev: %s\n",
> > > + csi2rx->source_subdev->name);
> > > + return -EINVAL;
> > > + }
> > > +
> > > + return v4l2_ctrl_g_ctrl_int64(ctrl);
> > > +}
> > > +
> > > static inline
> > > struct csi2rx_priv *v4l2_subdev_to_csi2rx(struct v4l2_subdev *subdev)
> > > {
> > > @@ -101,6 +158,55 @@ 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;
> > > + struct v4l2_subdev_format sd_fmt;
> > > + s64 pixel_rate;
> > > + int ret;
> > > + u8 bpp;
> > > +
> > > + sd_fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > > + sd_fmt.pad = 0;
> > > +
> > > + ret = v4l2_subdev_call(csi2rx->source_subdev, pad, get_fmt, NULL,
> > > + &sd_fmt);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + bpp = csi2rx_get_bpp(sd_fmt.format.code);
> > > + if (!bpp)
> > > + return -EINVAL;
> > > +
> > > + pixel_rate = csi2rx_get_pixel_rate(csi2rx);
> > > + if (pixel_rate < 0)
> > > + return pixel_rate;
> > > +
> > > + ret = phy_mipi_dphy_get_default_config(pixel_rate, bpp,
> > > + csi2rx->num_lanes, cfg);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + ret = phy_set_mode_ext(csi2rx->dphy, PHY_MODE_MIPI_DPHY,
> > > + PHY_MIPI_DPHY_SUBMODE_RX);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + ret = phy_power_on(csi2rx->dphy);
> > > + if (ret)
> > > + return ret;
> > Seems phy_power_on, then phy_set_mode_ext?
>
> Shouldn't the mode be set before the PHY is powered on so the correct
> power on procedure can be performed based on the mode of operation?
Of course, it is fine for cnds-dphy.
But it depends on HW design and also phy driver;
if the mode is controlled in PHY IP register, we can't access it before
phy_power_on if no phy_init called (e.g. clock/power is not enabled).
Just let you pay attention on the phy sequence.
Thanks
>
> >
> > > +
> > > + ret = phy_configure(csi2rx->dphy, &opts);
> > > + if (ret) {
> > > + /* Can't do anything if it fails. Ignore the return value. */
> > > + phy_power_off(csi2rx->dphy);
> > > + return ret;
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > static int csi2rx_start(struct csi2rx_priv *csi2rx)
> > > {
> > > unsigned int i;
> > > @@ -139,6 +245,17 @@ 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.
> > > @@ -169,10 +286,21 @@ 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]);
> > > @@ -200,6 +328,13 @@ 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)
> > > @@ -306,15 +441,6 @@ 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;
> > > - }
> > > -
> > > clk_prepare_enable(csi2rx->p_clk);
> > > dev_cfg = readl(csi2rx->base + CSI2RX_DEVICE_CFG_REG);
> > > clk_disable_unprepare(csi2rx->p_clk);
> > > @@ -339,7 +465,7 @@ 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;
> > > }
> > > @@ -460,6 +586,7 @@ 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;
> >
>