linux-kernel - Re: [PATCH 2/5] phy: qcom: edp: Introduce aux_cfg array for version specific aux settings

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Message-ID: <ZuJHtXrZIRDd7Kyg@hu-bjorande-lv.qualcomm.com>
Date: Wed, 11 Sep 2024 18:45:25 -0700
From: Bjorn Andersson <quic_bjorande@...cinc.com>
To: Soutrik Mukhopadhyay <quic_mukhopad@...cinc.com>
CC: <vkoul@...nel.org>, <kishon@...nel.org>, <konradybcio@...nel.org>,
        <andersson@...nel.org>, <simona@...ll.ch>,
        <dmitry.baryshkov@...aro.org>, <abel.vesa@...aro.org>,
        <robdclark@...il.com>, <quic_abhinavk@...cinc.com>, <sean@...rly.run>,
        <marijn.suijten@...ainline.org>, <airlied@...il.com>,
        <daniel@...ll.ch>, <maarten.lankhorst@...ux.intel.com>,
        <mripard@...nel.org>, <tzimmermann@...e.de>, <robh@...nel.org>,
        <krzk+dt@...nel.org>, <conor+dt@...nel.org>, <quic_khsieh@...cinc.com>,
        <konrad.dybcio@...aro.org>, <quic_parellan@...cinc.com>,
        <linux-arm-msm@...r.kernel.org>, <linux-phy@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <dri-devel@...ts.freedesktop.org>,
        <freedreno@...ts.freedesktop.org>, <devicetree@...r.kernel.org>,
        <quic_riteshk@...cinc.com>, <quic_vproddut@...cinc.com>
Subject: Re: [PATCH 2/5] phy: qcom: edp: Introduce aux_cfg array for version
 specific aux settings

On Wed, Sep 11, 2024 at 03:38:10PM +0530, Soutrik Mukhopadhyay wrote:
> In order to support different HW versions, introduce aux_cfg array
> to move v4 specific aux configuration settings.
> 
> Signed-off-by: Soutrik Mukhopadhyay <quic_mukhopad@...cinc.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-edp.c | 34 +++++++++++++++++------------
>  1 file changed, 20 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-edp.c b/drivers/phy/qualcomm/phy-qcom-edp.c
> index da2b32fb5b45..0f860a807d1b 100644
> --- a/drivers/phy/qualcomm/phy-qcom-edp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-edp.c
> @@ -90,6 +90,7 @@ struct phy_ver_ops {
>  
>  struct qcom_edp_phy_cfg {
>  	bool is_edp;
> +	u8 *aux_cfg;
>  	const struct qcom_edp_swing_pre_emph_cfg *swing_pre_emph_cfg;
>  	const struct phy_ver_ops *ver_ops;
>  };
> @@ -186,11 +187,14 @@ static const struct qcom_edp_swing_pre_emph_cfg edp_phy_swing_pre_emph_cfg = {
>  	.pre_emphasis_hbr3_hbr2 = &edp_pre_emp_hbr2_hbr3,
>  };
>  
> +static u8 edp_phy_aux_cfg_v4[10] = {
> +	0x00, 0x13, 0x24, 0x00, 0x0a, 0x26, 0x0a, 0x03, 0x37, 0x03
> +};
> +
>  static int qcom_edp_phy_init(struct phy *phy)
>  {
>  	struct qcom_edp *edp = phy_get_drvdata(phy);
>  	int ret;
> -	u8 cfg8;
>  
>  	ret = regulator_bulk_enable(ARRAY_SIZE(edp->supplies), edp->supplies);
>  	if (ret)
> @@ -222,22 +226,20 @@ static int qcom_edp_phy_init(struct phy *phy)
>  	 * even needed.
>  	 */
>  	if (edp->cfg->swing_pre_emph_cfg && !edp->is_edp)
> -		cfg8 = 0xb7;
> -	else
> -		cfg8 = 0x37;
> +		edp->cfg->aux_cfg[8] = 0xb7;

If you have multiple instances of the eDP PHY they will all point to the
same edp_phy_aux_cfg_v4[], so making instance-specific modifications
to that array will not be okay.


Make edp_phy_aux_cfg_v4[] const to reduce the likelihood for someone
else to make this mistake in the future and make a local copy of the
array on the stack so that you can modify it.

Regards,
Bjorn

>  
>  	writel(0xfc, edp->edp + DP_PHY_MODE);
>  
> -	writel(0x00, edp->edp + DP_PHY_AUX_CFG0);
> -	writel(0x13, edp->edp + DP_PHY_AUX_CFG1);
> -	writel(0x24, edp->edp + DP_PHY_AUX_CFG2);
> -	writel(0x00, edp->edp + DP_PHY_AUX_CFG3);
> -	writel(0x0a, edp->edp + DP_PHY_AUX_CFG4);
> -	writel(0x26, edp->edp + DP_PHY_AUX_CFG5);
> -	writel(0x0a, edp->edp + DP_PHY_AUX_CFG6);
> -	writel(0x03, edp->edp + DP_PHY_AUX_CFG7);
> -	writel(cfg8, edp->edp + DP_PHY_AUX_CFG8);
> -	writel(0x03, edp->edp + DP_PHY_AUX_CFG9);
> +	writel(edp->cfg->aux_cfg[0], edp->edp + DP_PHY_AUX_CFG0);
> +	writel(edp->cfg->aux_cfg[1], edp->edp + DP_PHY_AUX_CFG1);
> +	writel(edp->cfg->aux_cfg[2], edp->edp + DP_PHY_AUX_CFG2);
> +	writel(edp->cfg->aux_cfg[3], edp->edp + DP_PHY_AUX_CFG3);
> +	writel(edp->cfg->aux_cfg[4], edp->edp + DP_PHY_AUX_CFG4);
> +	writel(edp->cfg->aux_cfg[5], edp->edp + DP_PHY_AUX_CFG5);
> +	writel(edp->cfg->aux_cfg[6], edp->edp + DP_PHY_AUX_CFG6);
> +	writel(edp->cfg->aux_cfg[7], edp->edp + DP_PHY_AUX_CFG7);
> +	writel(edp->cfg->aux_cfg[8], edp->edp + DP_PHY_AUX_CFG8);
> +	writel(edp->cfg->aux_cfg[9], edp->edp + DP_PHY_AUX_CFG9);
>  
>  	writel(PHY_AUX_STOP_ERR_MASK | PHY_AUX_DEC_ERR_MASK |
>  	       PHY_AUX_SYNC_ERR_MASK | PHY_AUX_ALIGN_ERR_MASK |
> @@ -519,16 +521,19 @@ static const struct phy_ver_ops qcom_edp_phy_ops_v4 = {
>  };
>  
>  static const struct qcom_edp_phy_cfg sc7280_dp_phy_cfg = {
> +	.aux_cfg = edp_phy_aux_cfg_v4,
>  	.ver_ops = &qcom_edp_phy_ops_v4,
>  };
>  
>  static const struct qcom_edp_phy_cfg sc8280xp_dp_phy_cfg = {
> +	.aux_cfg = edp_phy_aux_cfg_v4,
>  	.swing_pre_emph_cfg = &dp_phy_swing_pre_emph_cfg,
>  	.ver_ops = &qcom_edp_phy_ops_v4,
>  };
>  
>  static const struct qcom_edp_phy_cfg sc8280xp_edp_phy_cfg = {
>  	.is_edp = true,
> +	.aux_cfg = edp_phy_aux_cfg_v4,
>  	.swing_pre_emph_cfg = &edp_phy_swing_pre_emph_cfg,
>  	.ver_ops = &qcom_edp_phy_ops_v4,
>  };
> @@ -707,6 +712,7 @@ static const struct phy_ver_ops qcom_edp_phy_ops_v6 = {
>  };
>  
>  static struct qcom_edp_phy_cfg x1e80100_phy_cfg = {
> +	.aux_cfg = edp_phy_aux_cfg_v4,
>  	.swing_pre_emph_cfg = &dp_phy_swing_pre_emph_cfg,
>  	.ver_ops = &qcom_edp_phy_ops_v6,
>  };
> -- 
> 2.17.1
>