Re: [PATCH WIP v4 2/9] media: qcom: camss: csiphy-3ph: Use odd bits for configuring C-PHY lanes

[Bryan O'Donoghue <bryan.odonoghue@linaro.org>]

On 01/03/2026 00:51, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <david@ixit.cz>
> 
> So far, only D-PHY mode was supported, which uses even bits when enabling
> or masking lanes. For C-PHY configuration, the hardware instead requires
> using the odd bits.
> 
> Since there can be unrecognized configuration allow returning failure.
> 
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>   .../platform/qcom/camss/camss-csiphy-2ph-1-0.c     |  8 ++--
>   .../platform/qcom/camss/camss-csiphy-3ph-1-0.c     | 49 +++++++++++++++++-----
>   drivers/media/platform/qcom/camss/camss-csiphy.c   |  5 +--
>   drivers/media/platform/qcom/camss/camss-csiphy.h   |  6 +--
>   4 files changed, 48 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c b/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c
> index 9d67e7fa6366a..bb4b91f69616b 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c
> @@ -94,9 +94,9 @@ static u8 csiphy_settle_cnt_calc(s64 link_freq, u32 timer_clk_rate)
>   	return settle_cnt;
>   }
>   
> -static void csiphy_lanes_enable(struct csiphy_device *csiphy,
> -				struct csiphy_config *cfg,
> -				s64 link_freq, u8 lane_mask)
> +static int csiphy_lanes_enable(struct csiphy_device *csiphy,
> +			       struct csiphy_config *cfg,
> +			       s64 link_freq, u8 lane_mask)
>   {
>   	struct csiphy_lanes_cfg *c = &cfg->csi2->lane_cfg;
>   	u8 settle_cnt;
> @@ -132,6 +132,8 @@ static void csiphy_lanes_enable(struct csiphy_device *csiphy,
>   		writel_relaxed(0x3f, csiphy->base +
>   			       CAMSS_CSI_PHY_INTERRUPT_CLEARn(l));
>   	}
> +
> +	return 0;
>   }
>   
>   static void csiphy_lanes_disable(struct csiphy_device *csiphy,
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
> index 4154832745525..cf83c9e062b81 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
> @@ -14,6 +14,7 @@
>   #include <linux/delay.h>
>   #include <linux/interrupt.h>
>   #include <linux/io.h>
> +#include <linux/media-bus-format.h>
>   
>   #define CSIPHY_3PH_LNn_CFG1(n)			(0x000 + 0x100 * (n))
>   #define CSIPHY_3PH_LNn_CFG1_SWI_REC_DLY_PRG	(BIT(7) | BIT(6))
> @@ -993,13 +994,22 @@ static void csiphy_gen2_config_lanes(struct csiphy_device *csiphy,
>   
>   static u8 csiphy_get_lane_mask(struct csiphy_lanes_cfg *lane_cfg)
>   {
> -	u8 lane_mask;
> -	int i;
> +	u8 lane_mask = 0;
>   
> -	lane_mask = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;
> +	switch (lane_cfg->phy_cfg) {
> +	case V4L2_MBUS_CSI2_CPHY:
> +		for (int i = 0; i < lane_cfg->num_data; i++)
> +			lane_mask |= BIT(lane_cfg->data[i].pos + 1);
> +		break;
> +	case V4L2_MBUS_CSI2_DPHY:
> +		lane_mask = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;
>   
> -	for (i = 0; i < lane_cfg->num_data; i++)
> -		lane_mask |= 1 << lane_cfg->data[i].pos;
> +		for (int i = 0; i < lane_cfg->num_data; i++)
> +			lane_mask |= BIT(lane_cfg->data[i].pos);
> +		break;
> +	default:
> +		break;
> +	}
>   
>   	return lane_mask;
>   }
> @@ -1027,10 +1037,11 @@ static bool csiphy_is_gen2(u32 version)
>   	return ret;
>   }
>   
> -static void csiphy_lanes_enable(struct csiphy_device *csiphy,
> -				struct csiphy_config *cfg,
> -				s64 link_freq, u8 lane_mask)
> +static int csiphy_lanes_enable(struct csiphy_device *csiphy,
> +			       struct csiphy_config *cfg,
> +			       s64 link_freq, u8 lane_mask)
>   {
> +	struct device *dev = csiphy->camss->dev;
>   	struct csiphy_lanes_cfg *c = &cfg->csi2->lane_cfg;
>   	struct csiphy_device_regs *regs = csiphy->regs;
>   	u8 settle_cnt;
> @@ -1039,9 +1050,23 @@ static void csiphy_lanes_enable(struct csiphy_device *csiphy,
>   
>   	settle_cnt = csiphy_settle_cnt_calc(link_freq, csiphy->timer_clk_rate);
>   
> -	val = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;
> -	for (i = 0; i < c->num_data; i++)
> -		val |= BIT(c->data[i].pos * 2);
> +	val = 0;
> +
> +	switch (c->phy_cfg) {
> +	case V4L2_MBUS_CSI2_CPHY:
> +		for (i = 0; i < c->num_data; i++)
> +			val |= BIT((c->data[i].pos * 2) + 1);
> +		break;
> +	case V4L2_MBUS_CSI2_DPHY:
> +		val = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;
> +
> +		for (i = 0; i < c->num_data; i++)
> +			val |= BIT(c->data[i].pos * 2);
> +		break;
> +	default:
> +		dev_err(dev, "Unsupported bus type %d\n", c->phy_cfg);
> +		return -EINVAL;
> +	}
>   
>   	writel_relaxed(val, csiphy->base +
>   		       CSIPHY_3PH_CMN_CSI_COMMON_CTRLn(regs->offset, 5));
> @@ -1068,6 +1093,8 @@ static void csiphy_lanes_enable(struct csiphy_device *csiphy,
>   		writel_relaxed(0, csiphy->base +
>   			       CSIPHY_3PH_CMN_CSI_COMMON_CTRLn(regs->offset, i));
>   	}
> +
> +	return 0;
>   }
>   
>   static void csiphy_lanes_disable(struct csiphy_device *csiphy,
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.c b/drivers/media/platform/qcom/camss/camss-csiphy.c
> index 62623393f4144..938600f3defe1 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy.c
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.c
> @@ -265,6 +265,7 @@ static int csiphy_set_power(struct v4l2_subdev *sd, int on)
>   static int csiphy_stream_on(struct csiphy_device *csiphy)
>   {
>   	struct csiphy_config *cfg = &csiphy->cfg;
> +	const struct csiphy_hw_ops *ops = csiphy->res->hw_ops;
>   	s64 link_freq;
>   	u8 lane_mask = csiphy->res->hw_ops->get_lane_mask(&cfg->csi2->lane_cfg);
>   	u8 bpp = csiphy_get_bpp(csiphy->res->formats->formats, csiphy->res->formats->nformats,
> @@ -295,9 +296,7 @@ static int csiphy_stream_on(struct csiphy_device *csiphy)
>   		wmb();
>   	}
>   
> -	csiphy->res->hw_ops->lanes_enable(csiphy, cfg, link_freq, lane_mask);
> -
> -	return 0;
> +	return ops->lanes_enable(csiphy, cfg, link_freq, lane_mask);
>   }
>   
>   /*
> diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/drivers/media/platform/qcom/camss/camss-csiphy.h
> index d198171700e73..21cf2ce931c1d 100644
> --- a/drivers/media/platform/qcom/camss/camss-csiphy.h
> +++ b/drivers/media/platform/qcom/camss/camss-csiphy.h
> @@ -73,9 +73,9 @@ struct csiphy_hw_ops {
>   	void (*hw_version_read)(struct csiphy_device *csiphy,
>   				struct device *dev);
>   	void (*reset)(struct csiphy_device *csiphy);
> -	void (*lanes_enable)(struct csiphy_device *csiphy,
> -			     struct csiphy_config *cfg,
> -			     s64 link_freq, u8 lane_mask);
> +	int (*lanes_enable)(struct csiphy_device *csiphy,
> +			    struct csiphy_config *cfg,
> +			    s64 link_freq, u8 lane_mask);
>   	void (*lanes_disable)(struct csiphy_device *csiphy,
>   			      struct csiphy_config *cfg);
>   	irqreturn_t (*isr)(int irq, void *dev);
> 
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>