Date:   Mon, 20 Feb 2023 05:40:43 -0800
From:   Piyush Malgujar <pmalgujar@marvell.com>
To:     Adrian Hunter <adrian.hunter@intel.com>
CC:     <linux-mmc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <ulf.hansson@linaro.org>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>,
        <yamada.masahiro@socionext.com>, <devicetree@vger.kernel.org>,
        Brad Larson <blarson@amd.com>, <jannadurai@marvell.com>,
        <cchavva@marvell.com>, Dhananjay Kangude <dkangude@cadence.com>
Subject: Re: [PATCH v2 1/5] drivers: mmc: sdhci-cadence: Reformat the code
Message-ID: <20230220134043.GB24729@Dell2s-9>
References: <20230123192735.21136-1-pmalgujar@marvell.com>
 <20230123192735.21136-2-pmalgujar@marvell.com>
 <d08a1fc5-727c-7845-7aeb-729c5aa68189@intel.com>
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In-Reply-To: <d08a1fc5-727c-7845-7aeb-729c5aa68189@intel.com>
User-Agent: Mutt/1.9.4 (2018-02-28)
Precedence: bulk

Hi Adrian,

Thank you for your review comments.

On Thu, Feb 02, 2023 at 08:42:33PM +0200, Adrian Hunter wrote:
> On 23/01/23 21:27, Piyush Malgujar wrote:
> > From: Dhananjay Kangude <dkangude@cadence.com>
> > 
> > Reformat the code so that further SD6 changes could be
> > added and it could be isolated from SD4 related code.
> > Also renamed functions accordingly.
> 
> It is good to have the renaming and white space changes
> in a separate patch, but there is also some restructuring
> in this patch that needs to be in 1 or more separate patches.
> 
> There are also still some white space changes in the next
> patch.
> 
> > 
> > Signed-off-by: Dhananjay Kangude <dkangude@cadence.com>
> > Co-developed-by: Jayanthi Annadurai <jannadurai@marvell.com>
> > Signed-off-by: Jayanthi Annadurai <jannadurai@marvell.com>
> > Signed-off-by: Piyush Malgujar <pmalgujar@marvell.com>
> > ---
> >  drivers/mmc/host/sdhci-cadence.c | 165 ++++++++++++++++++++-----------
> >  1 file changed, 110 insertions(+), 55 deletions(-)
> > 
> > diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
> > index 6f2de54a598773879bf339aae8450f63e1251509..cb108ff9abda32767b356bb572abdf8626746cd6 100644
> > --- a/drivers/mmc/host/sdhci-cadence.c
> > +++ b/drivers/mmc/host/sdhci-cadence.c
> > @@ -15,14 +15,14 @@
> >  
> >  #include "sdhci-pltfm.h"
> >  
> > -/* HRS - Host Register Set (specific to Cadence) */
> > +/* SD 4.0 Controller HRS - Host Register Set (specific to Cadence) */
> >  #define SDHCI_CDNS_HRS04		0x10		/* PHY access port */
> > -#define   SDHCI_CDNS_HRS04_ACK			BIT(26)
> > -#define   SDHCI_CDNS_HRS04_RD			BIT(25)
> > -#define   SDHCI_CDNS_HRS04_WR			BIT(24)
> > -#define   SDHCI_CDNS_HRS04_RDATA		GENMASK(23, 16)
> > -#define   SDHCI_CDNS_HRS04_WDATA		GENMASK(15, 8)
> > -#define   SDHCI_CDNS_HRS04_ADDR			GENMASK(5, 0)
> > +#define SDHCI_CDNS_SD4_HRS04_ACK		BIT(26)
> > +#define SDHCI_CDNS_SD4_HRS04_RD			BIT(25)
> > +#define SDHCI_CDNS_SD4_HRS04_WR			BIT(24)
> > +#define SDHCI_CDNS_SD4_HRS04_RDATA		GENMASK(23, 16)
> > +#define SDHCI_CDNS_SD4_HRS04_WDATA		GENMASK(15, 8)
> > +#define SDHCI_CDNS_SD4_HRS04_ADDR		GENMASK(5, 0)
> >  
> >  #define SDHCI_CDNS_HRS06		0x18		/* eMMC control */
> >  #define   SDHCI_CDNS_HRS06_TUNE_UP		BIT(15)
> > @@ -38,7 +38,7 @@
> >  /* SRS - Slot Register Set (SDHCI-compatible) */
> >  #define SDHCI_CDNS_SRS_BASE		0x200
> >  
> > -/* PHY */
> > +/* PHY registers for SD4 controller */
> >  #define SDHCI_CDNS_PHY_DLY_SD_HS	0x00
> >  #define SDHCI_CDNS_PHY_DLY_SD_DEFAULT	0x01
> >  #define SDHCI_CDNS_PHY_DLY_UHS_SDR12	0x02
> > @@ -59,24 +59,43 @@
> >   */
> >  #define SDHCI_CDNS_MAX_TUNING_LOOP	40
> >  
> > -struct sdhci_cdns_phy_param {
> > +struct sdhci_cdns_priv;
> > +
> > +struct sdhci_cdns_sd4_phy_param {
> >  	u8 addr;
> >  	u8 data;
> >  };
> >  
> > +struct sdhci_cdns_data {
> > +	int (*phy_init)(struct sdhci_cdns_priv *priv);
> > +	int (*set_tune_val)(struct sdhci_host *host, unsigned int val);
> > +};
> > +
> > +struct sdhci_cdns_sd4_phy {
> > +	unsigned int nr_phy_params;
> > +	struct sdhci_cdns_sd4_phy_param phy_params[];
> > +};
> > +
> >  struct sdhci_cdns_priv {
> >  	void __iomem *hrs_addr;
> >  	bool enhanced_strobe;
> > -	unsigned int nr_phy_params;
> > -	struct sdhci_cdns_phy_param phy_params[];
> > +	const struct sdhci_cdns_data *cdns_data;
> > +	void *phy;
> >  };
> >  
> > -struct sdhci_cdns_phy_cfg {
> > +struct sdhci_cdns_sd4_phy_cfg {
> >  	const char *property;
> >  	u8 addr;
> >  };
> >  
> > -static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
> > +struct sdhci_cdns_of_data {
> > +	const struct sdhci_pltfm_data *pltfm_data;
> > +	const struct sdhci_cdns_data *cdns_data;
> > +	int (*phy_probe)(struct platform_device *pdev,
> > +			 struct sdhci_cdns_priv *priv);
> > +};
> > +
> > +static const struct sdhci_cdns_sd4_phy_cfg sdhci_cdns_sd4_phy_cfgs[] = {
> >  	{ "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
> >  	{ "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
> >  	{ "cdns,phy-input-delay-sd-uhs-sdr12", SDHCI_CDNS_PHY_DLY_UHS_SDR12, },
> > @@ -90,80 +109,80 @@ static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
> >  	{ "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
> >  };
> >  
> > -static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
> > -				    u8 addr, u8 data)
> > +static int sdhci_cdns_sd4_write_phy_reg(struct sdhci_cdns_priv *priv,
> > +					u8 addr, u8 data)
> >  {
> >  	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
> >  	u32 tmp;
> >  	int ret;
> >  
> > -	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS04_ACK),
> > +	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_SD4_HRS04_ACK),
> >  				 0, 10);
> >  	if (ret)
> >  		return ret;
> >  
> > -	tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
> > -	      FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
> > +	tmp = FIELD_PREP(SDHCI_CDNS_SD4_HRS04_WDATA, data) |
> > +	      FIELD_PREP(SDHCI_CDNS_SD4_HRS04_ADDR, addr);
> >  	writel(tmp, reg);
> >  
> > -	tmp |= SDHCI_CDNS_HRS04_WR;
> > +	tmp |= SDHCI_CDNS_SD4_HRS04_WR;
> >  	writel(tmp, reg);
> >  
> > -	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
> > +	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_SD4_HRS04_ACK, 0, 10);
> >  	if (ret)
> >  		return ret;
> >  
> > -	tmp &= ~SDHCI_CDNS_HRS04_WR;
> > +	tmp &= ~SDHCI_CDNS_SD4_HRS04_WR;
> >  	writel(tmp, reg);
> >  
> > -	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS04_ACK),
> > +	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_SD4_HRS04_ACK),
> >  				 0, 10);
> >  
> >  	return ret;
> >  }
> >  
> > -static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
> > +static unsigned int sdhci_cdns_sd4_phy_param_count(struct device_node *np)
> >  {
> >  	unsigned int count = 0;
> >  	int i;
> >  
> > -	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
> > -		if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
> > +	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_sd4_phy_cfgs); i++)
> > +		if (of_property_read_bool(np, sdhci_cdns_sd4_phy_cfgs[i].property))
> >  			count++;
> >  
> >  	return count;
> >  }
> >  
> > -static void sdhci_cdns_phy_param_parse(struct device_node *np,
> > -				       struct sdhci_cdns_priv *priv)
> > +static void sdhci_cdns_sd4_phy_param_parse(struct device_node *np,
> > +					   struct sdhci_cdns_sd4_phy *phy)
> >  {
> > -	struct sdhci_cdns_phy_param *p = priv->phy_params;
> > +	struct sdhci_cdns_sd4_phy_param *p = phy->phy_params;
> >  	u32 val;
> >  	int ret, i;
> >  
> > -	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
> > -		ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
> > +	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_sd4_phy_cfgs); i++) {
> > +		ret = of_property_read_u32(np, sdhci_cdns_sd4_phy_cfgs[i].property,
> >  					   &val);
> >  		if (ret)
> >  			continue;
> >  
> > -		p->addr = sdhci_cdns_phy_cfgs[i].addr;
> > +		p->addr = sdhci_cdns_sd4_phy_cfgs[i].addr;
> >  		p->data = val;
> >  		p++;
> >  	}
> >  }
> >  
> > -static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
> > +static int sdhci_cdns_sd4_phy_init(struct sdhci_cdns_priv *priv)
> >  {
> >  	int ret, i;
> > +	struct sdhci_cdns_sd4_phy *phy = priv->phy;
> >  
> > -	for (i = 0; i < priv->nr_phy_params; i++) {
> > -		ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
> > -					       priv->phy_params[i].data);
> > +	for (i = 0; i < phy->nr_phy_params; i++) {
> > +		ret = sdhci_cdns_sd4_write_phy_reg(priv, phy->phy_params[i].addr,
> > +						   phy->phy_params[i].data);
> >  		if (ret)
> >  			return ret;
> >  	}
> > -
> >  	return 0;
> >  }
> >  
> > @@ -202,7 +221,28 @@ static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
> >  	return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
> >  }
> >  
> > -static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
> > +static int sdhci_cdns_sd4_phy_probe(struct platform_device *pdev,
> > +				    struct sdhci_cdns_priv *priv)
> > +{
> > +	unsigned int nr_phy_params;
> > +	struct sdhci_cdns_sd4_phy *phy;
> > +	struct device *dev = &pdev->dev;
> > +
> > +	nr_phy_params = sdhci_cdns_sd4_phy_param_count(dev->of_node);
> > +	phy = devm_kzalloc(dev, struct_size(phy, phy_params, nr_phy_params),
> > +			   GFP_KERNEL);
> > +	if (!phy)
> > +		return -ENOMEM;
> > +
> > +	phy->nr_phy_params = nr_phy_params;
> > +
> > +	sdhci_cdns_sd4_phy_param_parse(dev->of_node, phy);
> > +	priv->phy = phy;
> > +
> > +	return 0;
> > +}
> > +
> > +static int sdhci_cdns_sd4_set_tune_val(struct sdhci_host *host, unsigned int val)
> >  {
> >  	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
> >  	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
> > @@ -255,7 +295,7 @@ static int sdhci_cdns_execute_tuning(struct sdhci_host *host, u32 opcode)
> >  		return 0;
> >  
> >  	for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
> > -		if (sdhci_cdns_set_tune_val(host, i) ||
> > +		if (sdhci_cdns_sd4_set_tune_val(host, i) ||
> >  		    mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
> >  			cur_streak = 0;
> >  		} else { /* good */
> > @@ -272,7 +312,7 @@ static int sdhci_cdns_execute_tuning(struct sdhci_host *host, u32 opcode)
> >  		return -EIO;
> >  	}
> >  
> > -	return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
> > +	return sdhci_cdns_sd4_set_tune_val(host, end_of_streak - max_streak / 2);
> >  }
> >  
> >  static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
> > @@ -309,7 +349,7 @@ static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
> >  		sdhci_set_uhs_signaling(host, timing);
> >  }
> >  
> > -static const struct sdhci_ops sdhci_cdns_ops = {
> > +static const struct sdhci_ops sdhci_cdns_sd4_ops = {
> >  	.set_clock = sdhci_set_clock,
> >  	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
> >  	.set_bus_width = sdhci_set_bus_width,
> > @@ -319,12 +359,23 @@ static const struct sdhci_ops sdhci_cdns_ops = {
> >  };
> >  
> >  static const struct sdhci_pltfm_data sdhci_cdns_uniphier_pltfm_data = {
> > -	.ops = &sdhci_cdns_ops,
> > +	.ops = &sdhci_cdns_sd4_ops,
> >  	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
> >  };
> >  
> > -static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
> > -	.ops = &sdhci_cdns_ops,
> > +static const struct sdhci_pltfm_data sdhci_cdns_sd4_pltfm_data = {
> > +	.ops = &sdhci_cdns_sd4_ops,
> > +};
> > +
> > +static const struct sdhci_cdns_data sdhci_cdns_sd4_data = {
> > +	.phy_init = sdhci_cdns_sd4_phy_init,
> > +	.set_tune_val = sdhci_cdns_sd4_set_tune_val,
> > +};
> > +
> > +static const struct sdhci_cdns_of_data sdhci_cdns_sd4_of_data = {
> > +	.pltfm_data = &sdhci_cdns_sd4_pltfm_data,
> > +	.cdns_data = &sdhci_cdns_sd4_data,
> > +	.phy_probe = sdhci_cdns_sd4_phy_probe,
> >  };
> >  
> >  static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
> > @@ -350,11 +401,10 @@ static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
> >  static int sdhci_cdns_probe(struct platform_device *pdev)
> >  {
> >  	struct sdhci_host *host;
> > -	const struct sdhci_pltfm_data *data;
> > +	const struct sdhci_cdns_of_data *data;
> >  	struct sdhci_pltfm_host *pltfm_host;
> >  	struct sdhci_cdns_priv *priv;
> >  	struct clk *clk;
> > -	unsigned int nr_phy_params;
> >  	int ret;
> >  	struct device *dev = &pdev->dev;
> >  	static const u16 version = SDHCI_SPEC_400 << SDHCI_SPEC_VER_SHIFT;
> > @@ -368,12 +418,12 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
> >  		return ret;
> >  
> >  	data = of_device_get_match_data(dev);
> > -	if (!data)
> > -		data = &sdhci_cdns_pltfm_data;
> > +	if (!data) {
> > +		return PTR_ERR(clk);
> > +		goto disable_clk;
> 
> 'return' followed by 'goto'
> 
> Please review patches before submitting.
> 
> > +	}
> >  
> > -	nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
> > -	host = sdhci_pltfm_init(pdev, data,
> > -				struct_size(priv, phy_params, nr_phy_params));
> > +	host = sdhci_pltfm_init(pdev, data->pltfm_data, sizeof(*priv));
> >  	if (IS_ERR(host)) {
> >  		ret = PTR_ERR(host);
> >  		goto disable_clk;
> > @@ -383,9 +433,9 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
> >  	pltfm_host->clk = clk;
> >  
> >  	priv = sdhci_pltfm_priv(pltfm_host);
> > -	priv->nr_phy_params = nr_phy_params;
> >  	priv->hrs_addr = host->ioaddr;
> >  	priv->enhanced_strobe = false;
> > +	priv->cdns_data = data->cdns_data;
> >  	host->ioaddr += SDHCI_CDNS_SRS_BASE;
> >  	host->mmc_host_ops.hs400_enhanced_strobe =
> >  				sdhci_cdns_hs400_enhanced_strobe;
> > @@ -398,9 +448,11 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
> >  	if (ret)
> >  		goto free;
> >  
> > -	sdhci_cdns_phy_param_parse(dev->of_node, priv);
> > +	ret = data->phy_probe(pdev, priv);
> > +	if (ret)
> > +		goto free;
> >  
> > -	ret = sdhci_cdns_phy_init(priv);
> > +	ret = priv->cdns_data->phy_init(priv);
> >  	if (ret)
> >  		goto free;
> >  
> > @@ -429,7 +481,7 @@ static int sdhci_cdns_resume(struct device *dev)
> >  	if (ret)
> >  		return ret;
> >  
> > -	ret = sdhci_cdns_phy_init(priv);
> > +	ret = priv->cdns_data->phy_init(priv);
> >  	if (ret)
> >  		goto disable_clk;
> >  
> > @@ -455,7 +507,10 @@ static const struct of_device_id sdhci_cdns_match[] = {
> >  		.compatible = "socionext,uniphier-sd4hc",
> >  		.data = &sdhci_cdns_uniphier_pltfm_data,
> >  	},
> > -	{ .compatible = "cdns,sd4hc" },
> > +	{
> > +		.compatible = "cdns,sd4hc",
> > +		.data = &sdhci_cdns_sd4_of_data,
> 
> sdhci_cdns_uniphier_pltfm_data is a pointer to a struct sdhci_pltfm_data, but
> sdhci_cdns_sd4_of_data is a pointer to a struct sdhci_cdns_of_data.
> That is error prone.  For example, you dereference data->cdns_data
> unconditionally even though it does not exist for sdhci_cdns_uniphier_pltfm_data.
> 

This will be taken care in V3, will handle sdhci_cdns_uniphier_pltfm_data in same
manner as sdhci_cdns_sd4_of_data and make it compatible with the design.

> Also this patch is in conflict with the approach taken by:
> 
> https://lore.kernel.org/linux-mmc/20230119035136.21603-14-blarson@amd.com/
> 

The above patch seems to be specific to Elba Soc for SD4.
The approach taken in our patches is more generic modular and also incorporates
SD6 controller.

> > +	},
> >  	{ /* sentinel */ }
> >  };
> >  MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
> 

Rest of the comments will be taken care in V3.

Thanks,
Piyush