Re: [PATCH 3/3] media: Add support for Cadence CSI2TX 2.1

From: Maxime Ripard
Date: Sat Jul 20 2019 - 04:26:08 EST


Hi,

On Thu, Jul 18, 2019 at 12:15:09PM +0100, Jan Kotas wrote:
> This patch adds support for CSI2TX v2.1 version of the controller.
>
> Signed-off-by: Jan Kotas <jank@xxxxxxxxxxx>
> ---
> drivers/media/platform/cadence/cdns-csi2tx.c | 142 +++++++++++++++++++++------
> 1 file changed, 112 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/media/platform/cadence/cdns-csi2tx.c b/drivers/media/platform/cadence/cdns-csi2tx.c
> index 232259c71..e4d08acfb 100644
> --- a/drivers/media/platform/cadence/cdns-csi2tx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2tx.c
> @@ -52,6 +52,17 @@
> #define CSI2TX_STREAM_IF_CFG_REG(n) (0x100 + (n) * 4)
> #define CSI2TX_STREAM_IF_CFG_FILL_LEVEL(n) ((n) & 0x1f)
>
> +/* CSI2TX V2 Registers */
> +#define CSI2TX_V2_DPHY_CFG_REG 0x28
> +#define CSI2TX_V2_DPHY_CFG_RESET BIT(16)
> +#define CSI2TX_V2_DPHY_CFG_CLOCK_MODE BIT(10)
> +#define CSI2TX_V2_DPHY_CFG_MODE_MASK GENMASK(9, 8)
> +#define CSI2TX_V2_DPHY_CFG_MODE_LPDT (2 << 8)
> +#define CSI2TX_V2_DPHY_CFG_MODE_HS (1 << 8)
> +#define CSI2TX_V2_DPHY_CFG_MODE_ULPS (0 << 8)
> +#define CSI2TX_V2_DPHY_CFG_CLK_ENABLE BIT(4)
> +#define CSI2TX_V2_DPHY_CFG_LANE_ENABLE(n) BIT(n)
> +
> #define CSI2TX_LANES_MAX 4
> #define CSI2TX_STREAMS_MAX 4
>
> @@ -70,6 +81,13 @@ struct csi2tx_fmt {
> u32 bpp;
> };
>
> +struct csi2tx_priv;
> +
> +/* CSI2TX Variant Operations */
> +struct csi2tx_vops {
> + void (*dphy_setup)(struct csi2tx_priv *csi2tx);
> +};
> +
> struct csi2tx_priv {
> struct device *dev;
> unsigned int count;
> @@ -82,6 +100,8 @@ struct csi2tx_priv {
>
> void __iomem *base;
>
> + struct csi2tx_vops *vops;
> +
> struct clk *esc_clk;
> struct clk *p_clk;
> struct clk *pixel_clk[CSI2TX_STREAMS_MAX];
> @@ -209,53 +229,92 @@ static const struct v4l2_subdev_pad_ops csi2tx_pad_ops = {
> .set_fmt = csi2tx_set_pad_format,
> };
>
> -static void csi2tx_reset(struct csi2tx_priv *csi2tx)
> +/* Set Wake Up value in the D-PHY */
> +static void csi2tx_dphy_set_wakeup(struct csi2tx_priv *csi2tx)
> {
> - writel(CSI2TX_CONFIG_SRST_REQ, csi2tx->base + CSI2TX_CONFIG_REG);
> -
> - udelay(10);
> + writel(CSI2TX_DPHY_CLK_WAKEUP_ULPS_CYCLES(32),
> + csi2tx->base + CSI2TX_DPHY_CLK_WAKEUP_REG);
> }
>
> -static int csi2tx_start(struct csi2tx_priv *csi2tx)
> +/*
> + * Finishes the D-PHY initialization
> + * reg dphy cfg value to be used
> + */
> +static void csi2tx_dphy_init_finish(struct csi2tx_priv *csi2tx, u32 reg)
> {
> - struct media_entity *entity = &csi2tx->subdev.entity;
> - struct media_link *link;
> unsigned int i;
> - u32 reg;
>
> - csi2tx_reset(csi2tx);
> + udelay(10);
>
> - writel(CSI2TX_CONFIG_CFG_REQ, csi2tx->base + CSI2TX_CONFIG_REG);
> + /* Enable our (clock and data) lanes */
> + reg |= CSI2TX_DPHY_CFG_CLK_ENABLE;
> + for (i = 0; i < csi2tx->num_lanes; i++)
> + reg |= CSI2TX_DPHY_CFG_LANE_ENABLE(csi2tx->lanes[i] - 1);
> + writel(reg, csi2tx->base + CSI2TX_DPHY_CFG_REG);
>
> udelay(10);
>
> - /* Configure our PPI interface with the D-PHY */
> - writel(CSI2TX_DPHY_CLK_WAKEUP_ULPS_CYCLES(32),
> - csi2tx->base + CSI2TX_DPHY_CLK_WAKEUP_REG);
> + /* Switch to HS mode */
> + reg &= ~CSI2TX_DPHY_CFG_MODE_MASK;
> + writel(reg | CSI2TX_DPHY_CFG_MODE_HS,
> + csi2tx->base + CSI2TX_DPHY_CFG_REG);
> +}
> +
> +/* Configures D-PHY in CSIv1.3 */
> +static void csi2tx_dphy_setup(struct csi2tx_priv *csi2tx)
> +{
> + u32 reg;
> + unsigned int i;
> +
> + csi2tx_dphy_set_wakeup(csi2tx);
>
> /* Put our lanes (clock and data) out of reset */
> reg = CSI2TX_DPHY_CFG_CLK_RESET | CSI2TX_DPHY_CFG_MODE_LPDT;
> for (i = 0; i < csi2tx->num_lanes; i++)
> - reg |= CSI2TX_DPHY_CFG_LANE_RESET(csi2tx->lanes[i]);
> + reg |= CSI2TX_DPHY_CFG_LANE_RESET(csi2tx->lanes[i] - 1);

This looks like a separate change?

> writel(reg, csi2tx->base + CSI2TX_DPHY_CFG_REG);
>
> - udelay(10);
> + csi2tx_dphy_init_finish(csi2tx, reg);
> +}
>
> - /* Enable our (clock and data) lanes */
> - reg |= CSI2TX_DPHY_CFG_CLK_ENABLE;
> - for (i = 0; i < csi2tx->num_lanes; i++)
> - reg |= CSI2TX_DPHY_CFG_LANE_ENABLE(csi2tx->lanes[i]);

And you have a similar change here that should be in a separate patch,
with a proper explanation.

Otherwise, the rest looks good.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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