Re: [PATCH v6 2/8] media: qcom: camss: csiphy-3ph: Use odd bits for configuring C-PHY lanes

[Frank Li <Frank.li@nxp.com>]

On Wed, Jun 03, 2026 at 01:30:40AM +0200, David Heidelberg wrote:
> 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.
>
> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> Acked-by: Cory Keitz <ckeitz@amazon.com>
> Reviewed-by: Bryan O'Donoghue <bod@kernel.org>

Suppose two Bryan is the same person?

> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
>  .../platform/qcom/camss/camss-csiphy-3ph-1-0.c     | 39 +++++++++++++++++-----
>  1 file changed, 31 insertions(+), 8 deletions(-)
>
> 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 dac8d2ecf7995..15876eb973718 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
> @@ -9,16 +9,17 @@
>   */
>
>  #include "camss.h"
>  #include "camss-csiphy.h"
>
>  #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))
>  #define CSIPHY_3PH_LNn_CFG2(n)			(0x004 + 0x100 * (n))
>  #define CSIPHY_3PH_LNn_CFG2_LP_REC_EN_INT	BIT(3)
>  #define CSIPHY_3PH_LNn_CFG3(n)			(0x008 + 0x100 * (n))
>  #define CSIPHY_3PH_LNn_CFG4(n)			(0x00c + 0x100 * (n))
>  #define CSIPHY_3PH_LNn_CFG4_T_HS_CLK_MISS	0xa4
> @@ -1108,23 +1109,32 @@ static void csiphy_gen2_config_lanes(struct csiphy_device *csiphy,
>  		writel_relaxed(val, csiphy->base + r->reg_addr);
>  		if (r->delay_us)
>  			udelay(r->delay_us);
>  	}
>  }
>
>  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);

suggest small tuning to move common logic out of switch

switch (lane_cfg->phy_cfg) {
case V4L2_MBUS_CSI2_CPHY:
	off = 1;
	lane_mask = 0;
case V4L2_MBUS_CSI2_DPHY:
	off = 0;
	lane_mask = CSIPHY_3PH_CMN_CSI_COMMON_CTRL5_CLK_ENABLE;
}

for (int i = 0; i < lane_cfg->num_data; i++)
	lane_mask |= BIT(lane_cfg->data[i].pos+ off);

the same as below block

Frank
> +		break;
> +	default:
> +		break;
> +	}
>
>  	return lane_mask;
>  }
>
>  static bool csiphy_is_gen2(u32 version)
>  {
>  	bool ret = false;
>
> @@ -1155,19 +1165,32 @@ static void csiphy_lanes_enable(struct csiphy_device *csiphy,
>  	struct csiphy_lanes_cfg *c = &cfg->csi2->lane_cfg;
>  	struct csiphy_device_regs *regs = csiphy->regs;
>  	u8 settle_cnt;
>  	u8 val;
>  	int i;
>
>  	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:
> +		WARN_ONCE(1, "Unsupported bus type %d!\n", c->phy_cfg);
> +	}
>
>  	writel_relaxed(val, csiphy->base +
>  		       CSIPHY_3PH_CMN_CSI_COMMON_CTRLn(regs->offset, 5));
>
>  	val = CSIPHY_3PH_CMN_CSI_COMMON_CTRL6_COMMON_PWRDN_B;
>  	writel_relaxed(val, csiphy->base +
>  		       CSIPHY_3PH_CMN_CSI_COMMON_CTRLn(regs->offset, 6));
>
>
> --
> 2.53.0
>