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Date:   Thu, 7 Oct 2021 03:02:48 +0300
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Pratyush Yadav <p.yadav@ti.com>
Cc:     Vinod Koul <vkoul@kernel.org>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
        Nikhil Devshatwar <nikhil.nd@ti.com>,
        Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org
Subject: Re: [PATCH v5 1/6] phy: cdns-dphy: Prepare for Rx support
Message-ID: <YV45KDonmDV8BR+y@pendragon.ideasonboard.com>
References: <20210902185543.18875-1-p.yadav@ti.com>
 <20210902185543.18875-2-p.yadav@ti.com>
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In-Reply-To: <20210902185543.18875-2-p.yadav@ti.com>
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Hi Pratyush,

Thank you for the patch.

On Fri, Sep 03, 2021 at 12:25:38AM +0530, Pratyush Yadav wrote:
> The Rx programming sequence differs from the Tx programming sequence.
> Currently only Tx mode is supported. For example, the power on and off,
> validation, and configuration procedures are all different between Rx
> and Tx DPHYs. Currently they are only written from a Tx point of view
> and they won't work with an Rx DPHY.
> 
> Set the PHY ops from driver data, which makes it possible to use
> different PHY callbacks for Rx and Tx modes. Rename cdns_dphy_ops to
> cdns_dphy_tx_ops since they are only used by the Tx path. Also move
> probe() and remove() to a new struct called cdns_dphy_common_ops. These
> can be used by both Rx and Tx paths. cdns_dphy_rx_ops is not added since
> it is not needed by the reference Rx mode implementation as of now. It
> can be added later if needed.
> 
> The clocks "psm" and "pll_ref" are not used by the Rx path so check for
> them in the Tx path's probe() callback.
> 
> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> 
> ---
> 
> Changes in v5:
> - Based on Laurent's suggestion, add cdns_dphy_info which contains the
>   phy_ops and cdns_dphy_tx_ops (renamed from cdns_dphy_ops). This lets us
>   get rid of the phy ops wrappers.
> - Move probe() and remove() into cdns_dphy_common_ops() since they can
>   be used by both modes. Drop the check in power_on().
> - Get the clocks in the tx ops probe to make sure they are mandatory for
>   Tx mode but not for Rx mode.
> 
> Changes in v4:
> - Instead of having both Rx and Tx modes in the same driver data, keep
>   them separate since the op selection is based on compatible now. For
>   that reason, the cdns_dphy_driver_data struct is no longer needed.
> - Rename ref_dphy_ops to tx_ref_dphy_ops to clarify their purpose.
> - Drop submode checks in validate() hook.
> 
>  drivers/phy/cadence/cdns-dphy.c | 169 ++++++++++++++++++++------------
>  1 file changed, 108 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
> index ba042e39cfaf..e2c2b27c6539 100644
> --- a/drivers/phy/cadence/cdns-dphy.c
> +++ b/drivers/phy/cadence/cdns-dphy.c
> @@ -72,9 +72,13 @@ enum cdns_dphy_clk_lane_cfg {
>  };
>  
>  struct cdns_dphy;
> -struct cdns_dphy_ops {
> +
> +struct cdns_dphy_common_ops {
>  	int (*probe)(struct cdns_dphy *dphy);
>  	void (*remove)(struct cdns_dphy *dphy);
> +};
> +
> +struct cdns_dphy_tx_ops {
>  	void (*set_psm_div)(struct cdns_dphy *dphy, u8 div);
>  	void (*set_clk_lane_cfg)(struct cdns_dphy *dphy,
>  				 enum cdns_dphy_clk_lane_cfg cfg);
> @@ -83,12 +87,21 @@ struct cdns_dphy_ops {
>  	unsigned long (*get_wakeup_time_ns)(struct cdns_dphy *dphy);
>  };
>  
> +struct cdns_dphy_info {
> +	const struct phy_ops *phy_ops;
> +	const struct cdns_dphy_common_ops *common_ops;
> +
> +	/* Only set when DPHY is to be used in Tx mode. */
> +	const struct cdns_dphy_tx_ops *tx_ops;
> +};
> +
>  struct cdns_dphy {
>  	struct cdns_dphy_cfg cfg;
>  	void __iomem *regs;
> +	struct device *dev;
>  	struct clk *psm_clk;
>  	struct clk *pll_ref_clk;
> -	const struct cdns_dphy_ops *ops;
> +	const struct cdns_dphy_info *info;
>  	struct phy *phy;
>  };
>  
> @@ -135,6 +148,7 @@ static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
>  
>  static int cdns_dphy_setup_psm(struct cdns_dphy *dphy)
>  {
> +	const struct cdns_dphy_tx_ops *ops = dphy->info->tx_ops;
>  	unsigned long psm_clk_hz = clk_get_rate(dphy->psm_clk);
>  	unsigned long psm_div;
>  
> @@ -142,8 +156,8 @@ static int cdns_dphy_setup_psm(struct cdns_dphy *dphy)
>  		return -EINVAL;
>  
>  	psm_div = DIV_ROUND_CLOSEST(psm_clk_hz, 1000000);
> -	if (dphy->ops->set_psm_div)
> -		dphy->ops->set_psm_div(dphy, psm_div);
> +	if (ops && ops->set_psm_div)
> +		ops->set_psm_div(dphy, psm_div);
>  
>  	return 0;
>  }
> @@ -151,20 +165,31 @@ static int cdns_dphy_setup_psm(struct cdns_dphy *dphy)
>  static void cdns_dphy_set_clk_lane_cfg(struct cdns_dphy *dphy,
>  				       enum cdns_dphy_clk_lane_cfg cfg)
>  {
> -	if (dphy->ops->set_clk_lane_cfg)
> -		dphy->ops->set_clk_lane_cfg(dphy, cfg);
> +	const struct cdns_dphy_tx_ops *ops = dphy->info->tx_ops;
> +
> +	if (ops && ops->set_clk_lane_cfg)
> +		ops->set_clk_lane_cfg(dphy, cfg);
>  }
>  
>  static void cdns_dphy_set_pll_cfg(struct cdns_dphy *dphy,
>  				  const struct cdns_dphy_cfg *cfg)
>  {
> -	if (dphy->ops->set_pll_cfg)
> -		dphy->ops->set_pll_cfg(dphy, cfg);
> +	const struct cdns_dphy_tx_ops *ops = dphy->info->tx_ops;
> +
> +	if (ops && ops->set_pll_cfg)
> +		ops->set_pll_cfg(dphy, cfg);
>  }
>  
>  static unsigned long cdns_dphy_get_wakeup_time_ns(struct cdns_dphy *dphy)
>  {
> -	return dphy->ops->get_wakeup_time_ns(dphy);
> +	const struct cdns_dphy_tx_ops *ops = dphy->info->tx_ops;
> +
> +	if (!ops || !ops->get_wakeup_time_ns) {
> +		dev_err(dphy->dev, "get_wakeup_time_ns() is required\n");
> +		return 0;
> +	}
> +
> +	return ops->get_wakeup_time_ns(dphy);
>  }
>  
>  static unsigned long cdns_dphy_ref_get_wakeup_time_ns(struct cdns_dphy *dphy)
> @@ -199,20 +224,9 @@ static void cdns_dphy_ref_set_psm_div(struct cdns_dphy *dphy, u8 div)
>  	       dphy->regs + DPHY_PSM_CFG);
>  }
>  
> -/*
> - * This is the reference implementation of DPHY hooks. Specific integration of
> - * this IP may have to re-implement some of them depending on how they decided
> - * to wire things in the SoC.
> - */
> -static const struct cdns_dphy_ops ref_dphy_ops = {
> -	.get_wakeup_time_ns = cdns_dphy_ref_get_wakeup_time_ns,
> -	.set_pll_cfg = cdns_dphy_ref_set_pll_cfg,
> -	.set_psm_div = cdns_dphy_ref_set_psm_div,
> -};
> -
> -static int cdns_dphy_config_from_opts(struct phy *phy,
> -				      struct phy_configure_opts_mipi_dphy *opts,
> -				      struct cdns_dphy_cfg *cfg)
> +static int cdns_dphy_tx_config_from_opts(struct phy *phy,
> +					 struct phy_configure_opts_mipi_dphy *opts,
> +					 struct cdns_dphy_cfg *cfg)
>  {
>  	struct cdns_dphy *dphy = phy_get_drvdata(phy);
>  	unsigned int dsi_hfp_ext = 0;
> @@ -232,24 +246,14 @@ static int cdns_dphy_config_from_opts(struct phy *phy,
>  	return 0;
>  }
>  
> -static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
> -			      union phy_configure_opts *opts)
> -{
> -	struct cdns_dphy_cfg cfg = { 0 };
> -
> -	if (mode != PHY_MODE_MIPI_DPHY)
> -		return -EINVAL;
> -
> -	return cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
> -}
> -
> -static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
> +static int cdns_dphy_tx_configure(struct phy *phy,
> +				  union phy_configure_opts *opts)
>  {
>  	struct cdns_dphy *dphy = phy_get_drvdata(phy);
>  	struct cdns_dphy_cfg cfg = { 0 };
>  	int ret;
>  
> -	ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
> +	ret = cdns_dphy_tx_config_from_opts(dphy->phy, &opts->mipi_dphy, &cfg);
>  	if (ret)
>  		return ret;
>  
> @@ -279,7 +283,19 @@ static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
>  	return 0;
>  }
>  
> -static int cdns_dphy_power_on(struct phy *phy)
> +static int cdns_dphy_tx_validate(struct phy *phy, enum phy_mode mode,
> +				 int submode, union phy_configure_opts *opts)
> +{
> +	struct cdns_dphy *dphy = phy_get_drvdata(phy);
> +	struct cdns_dphy_cfg cfg = { 0 };
> +
> +	if (mode != PHY_MODE_MIPI_DPHY)
> +		return -EINVAL;
> +
> +	return cdns_dphy_tx_config_from_opts(dphy->phy, &opts->mipi_dphy, &cfg);
> +}
> +
> +static int cdns_dphy_tx_power_on(struct phy *phy)
>  {
>  	struct cdns_dphy *dphy = phy_get_drvdata(phy);
>  
> @@ -293,7 +309,7 @@ static int cdns_dphy_power_on(struct phy *phy)
>  	return 0;
>  }
>  
> -static int cdns_dphy_power_off(struct phy *phy)
> +static int cdns_dphy_tx_power_off(struct phy *phy)
>  {
>  	struct cdns_dphy *dphy = phy_get_drvdata(phy);
>  
> @@ -303,16 +319,51 @@ static int cdns_dphy_power_off(struct phy *phy)
>  	return 0;
>  }
>  
> -static const struct phy_ops cdns_dphy_ops = {
> -	.configure	= cdns_dphy_configure,
> -	.validate	= cdns_dphy_validate,
> -	.power_on	= cdns_dphy_power_on,
> -	.power_off	= cdns_dphy_power_off,
> +static int cdns_dphy_tx_probe(struct cdns_dphy *dphy)
> +{
> +	dphy->psm_clk = devm_clk_get(dphy->dev, "psm");
> +	if (IS_ERR(dphy->psm_clk))
> +		return PTR_ERR(dphy->psm_clk);
> +
> +	dphy->pll_ref_clk = devm_clk_get(dphy->dev, "pll_ref");
> +	if (IS_ERR(dphy->pll_ref_clk))
> +		return PTR_ERR(dphy->pll_ref_clk);
> +
> +	return 0;
> +}
> +
> +/*
> + * This is the reference implementation of DPHY hooks. Specific integration of
> + * this IP may have to re-implement some of them depending on how they decided
> + * to wire things in the SoC.
> + */
> +static const struct cdns_dphy_tx_ops tx_ref_dphy_ops = {
> +	.get_wakeup_time_ns = cdns_dphy_ref_get_wakeup_time_ns,
> +	.set_pll_cfg = cdns_dphy_ref_set_pll_cfg,
> +	.set_psm_div = cdns_dphy_ref_set_psm_div,
> +};
> +
> +static const struct cdns_dphy_common_ops tx_ref_common_ops = {
> +	.probe = cdns_dphy_tx_probe,
> +};
> +
> +static const struct phy_ops tx_ref_phy_ops = {
> +	.power_on = cdns_dphy_tx_power_on,
> +	.power_off = cdns_dphy_tx_power_off,
> +	.validate = cdns_dphy_tx_validate,
> +	.configure = cdns_dphy_tx_configure,
> +};
> +
> +static const struct cdns_dphy_info tx_ref_info = {
> +	.phy_ops = &tx_ref_phy_ops,
> +	.common_ops = &tx_ref_common_ops,
> +	.tx_ops = &tx_ref_dphy_ops,
>  };
>  
>  static int cdns_dphy_probe(struct platform_device *pdev)
>  {
>  	struct phy_provider *phy_provider;
> +	const struct cdns_dphy_info *info;
>  	struct cdns_dphy *dphy;
>  	int ret;
>  
> @@ -320,34 +371,29 @@ static int cdns_dphy_probe(struct platform_device *pdev)
>  	if (!dphy)
>  		return -ENOMEM;
>  	dev_set_drvdata(&pdev->dev, dphy);
> +	dphy->dev = &pdev->dev;
>  
> -	dphy->ops = of_device_get_match_data(&pdev->dev);
> -	if (!dphy->ops)
> +	info = of_device_get_match_data(&pdev->dev);
> +	if (!info)
>  		return -EINVAL;
>  
> +	dphy->info = info;
> +
>  	dphy->regs = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(dphy->regs))
>  		return PTR_ERR(dphy->regs);
>  
> -	dphy->psm_clk = devm_clk_get(&pdev->dev, "psm");
> -	if (IS_ERR(dphy->psm_clk))
> -		return PTR_ERR(dphy->psm_clk);
> -
> -	dphy->pll_ref_clk = devm_clk_get(&pdev->dev, "pll_ref");
> -	if (IS_ERR(dphy->pll_ref_clk))
> -		return PTR_ERR(dphy->pll_ref_clk);
> -
> -	if (dphy->ops->probe) {
> -		ret = dphy->ops->probe(dphy);
> +	if (info->common_ops && info->common_ops->probe) {
> +		ret = info->common_ops->probe(dphy);
>  		if (ret)
>  			return ret;
>  	}
>  
> -	dphy->phy = devm_phy_create(&pdev->dev, NULL, &cdns_dphy_ops);
> +	dphy->phy = devm_phy_create(&pdev->dev, NULL, info->phy_ops);
>  	if (IS_ERR(dphy->phy)) {
>  		dev_err(&pdev->dev, "failed to create PHY\n");
> -		if (dphy->ops->remove)
> -			dphy->ops->remove(dphy);
> +		if (info->common_ops && info->common_ops->remove)
> +			info->common_ops->remove(dphy);
>  		return PTR_ERR(dphy->phy);
>  	}
>  
> @@ -361,15 +407,16 @@ static int cdns_dphy_probe(struct platform_device *pdev)
>  static int cdns_dphy_remove(struct platform_device *pdev)
>  {
>  	struct cdns_dphy *dphy = dev_get_drvdata(&pdev->dev);
> +	const struct cdns_dphy_info *info = dphy->info;
>  
> -	if (dphy->ops->remove)
> -		dphy->ops->remove(dphy);
> +	if (info->common_ops && info->common_ops->remove)
> +		info->common_ops->remove(dphy);
>  
>  	return 0;
>  }
>  
>  static const struct of_device_id cdns_dphy_of_match[] = {
> -	{ .compatible = "cdns,dphy", .data = &ref_dphy_ops },
> +	{ .compatible = "cdns,dphy", .data = &tx_ref_info },
>  	{ /* sentinel */ },
>  };
>  MODULE_DEVICE_TABLE(of, cdns_dphy_of_match);

-- 
Regards,

Laurent Pinchart