[PATCH 1/3] dt-bindings: sdhci-of-at91: new compatible string and update properties

[PATCH 1/3] dt-bindings: sdhci-of-at91: new compatible string and update properties

[Ludovic Desroches]

There is a new compatible string for the SAM9X60 sdhci device. It involves
an update of the properties about the clocks stuff.

Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
---
 .../devicetree/bindings/mmc/sdhci-atmel.txt   | 25 ++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
index 1b662d7171a0..364ceea330b6 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
@@ -5,12 +5,19 @@ Documentation/devicetree/bindings/mmc/mmc.txt and the properties used by the
 sdhci-of-at91 driver.
 
 Required properties:
-- compatible:		Must be "atmel,sama5d2-sdhci".
+- compatible:		Must be "atmel,sama5d2-sdhci" or "microchip,sam9x60-sdhci".
 - clocks:		Phandlers to the clocks.
-- clock-names:		Must be "hclock", "multclk", "baseclk";
+- clock-names:		Must be "hclock", "multclk", "baseclk" for
+			"atmel,sama5d2-sdhci".
+			Must be "hclock", "multclk" for "microchip,sam9x60-sdhci".
 
+Optional properties:
+- assigned-clocks:	The same with "multclk".
+- assigned-clock-rates	The rate of "multclk" in order to not rely on the
+			gck configuration set by previous components.
 
-Example:
+
+Examples:
 
 sdmmc0: sdio-host@a0000000 {
 	compatible = "atmel,sama5d2-sdhci";
@@ -18,4 +25,16 @@ sdmmc0: sdio-host@a0000000 {
 	interrupts = <31 IRQ_TYPE_LEVEL_HIGH 0>;
 	clocks = <&sdmmc0_hclk>, <&sdmmc0_gclk>, <&main>;
 	clock-names = "hclock", "multclk", "baseclk";
+	assigned-clocks = <&sdmmc0_gclk>;
+	assigned-clock-rates = <480000000>;
+};
+
+sdmmc0: sdio-host@80000000 {
+	compatible = "microchip,sam9x60-sdhci";
+	reg = <0x80000000 0x300>;
+	interrupts = <12 IRQ_TYPE_LEVEL_HIGH 0>;
+	clocks = <&pmc PMC_TYPE_PERIPHERAL 12>, <&pmc PMC_TYPE_GCK 12>;
+	clock-names = "hclock", "multclk";
+	assigned-clocks = <&pmc PMC_TYPE_GCK 12>;
+	assigned-clock-rates = <100000000>;
 };
-- 
2.23.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 2/3] mmc: sdhci-of-at91: rework clocks management to support SAM9x60 device

[Ludovic Desroches]

In the SAM9x60 SoC, there are only two clocks instead of three for the
SDHCI device. The base clk is no longer provided, it is generated
internally from the mult clk.

The values of the base clk and mul in the capabilities registers may not
reflect the reality as the mult clk is a programmable clock which can take
several rates. As we can't trust those values, take them from the clock
tree and update the capabilities according to.

As we can have the same pitfall, in some cases, with the SAMA5D2 Soc,
stop relying on capabilities too.

Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
---
 drivers/mmc/host/sdhci-of-at91.c | 104 +++++++++++++++++--------------
 1 file changed, 57 insertions(+), 47 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
index e7d1920729fb..a9c126f14d85 100644
--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -30,7 +30,14 @@
 
 #define SDHCI_AT91_PRESET_COMMON_CONF	0x400 /* drv type B, programmable clock mode */
 
+struct sdhci_at91_soc_data {
+	const struct sdhci_pltfm_data *pdata;
+	bool baseclk_is_generated_internally;
+	unsigned int divider_for_baseclk;
+};
+
 struct sdhci_at91_priv {
+	const struct sdhci_at91_soc_data *soc_data;
 	struct clk *hclock;
 	struct clk *gck;
 	struct clk *mainck;
@@ -130,12 +137,24 @@ static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
 	.set_power		= sdhci_at91_set_power,
 };
 
-static const struct sdhci_pltfm_data soc_data_sama5d2 = {
+static const struct sdhci_pltfm_data sdhci_sama5d2_pdata = {
 	.ops = &sdhci_at91_sama5d2_ops,
 };
 
+static const struct sdhci_at91_soc_data soc_data_sama5d2 = {
+	.pdata = &sdhci_sama5d2_pdata,
+	.baseclk_is_generated_internally = false,
+};
+
+static const struct sdhci_at91_soc_data soc_data_sam9x60 = {
+	.pdata = &sdhci_sama5d2_pdata,
+	.baseclk_is_generated_internally = true,
+	.divider_for_baseclk = 2,
+};
+
 static const struct of_device_id sdhci_at91_dt_match[] = {
 	{ .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
+	{ .compatible = "microchip,sam9x60-sdhci", .data = &soc_data_sam9x60 },
 	{}
 };
 MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
@@ -145,50 +164,36 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
 	struct sdhci_host *host = dev_get_drvdata(dev);
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
-	int ret;
 	unsigned int			caps0, caps1;
 	unsigned int			clk_base, clk_mul;
-	unsigned int			gck_rate, real_gck_rate;
+	unsigned int			gck_rate, clk_base_rate;
 	unsigned int			preset_div;
 
-	/*
-	 * The mult clock is provided by as a generated clock by the PMC
-	 * controller. In order to set the rate of gck, we have to get the
-	 * base clock rate and the clock mult from capabilities.
-	 */
 	clk_prepare_enable(priv->hclock);
 	caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
 	caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
-	clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
-	clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
-	gck_rate = clk_base * 1000000 * (clk_mul + 1);
-	ret = clk_set_rate(priv->gck, gck_rate);
-	if (ret < 0) {
-		dev_err(dev, "failed to set gck");
-		clk_disable_unprepare(priv->hclock);
-		return ret;
-	}
-	/*
-	 * We need to check if we have the requested rate for gck because in
-	 * some cases this rate could be not supported. If it happens, the rate
-	 * is the closest one gck can provide. We have to update the value
-	 * of clk mul.
-	 */
-	real_gck_rate = clk_get_rate(priv->gck);
-	if (real_gck_rate != gck_rate) {
-		clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
-		caps1 &= (~SDHCI_CLOCK_MUL_MASK);
-		caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) &
-			  SDHCI_CLOCK_MUL_MASK);
-		/* Set capabilities in r/w mode. */
-		writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN,
-		       host->ioaddr + SDMMC_CACR);
-		writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
-		/* Set capabilities in ro mode. */
-		writel(0, host->ioaddr + SDMMC_CACR);
-		dev_info(dev, "update clk mul to %u as gck rate is %u Hz\n",
-			 clk_mul, real_gck_rate);
-	}
+
+	gck_rate = clk_get_rate(priv->gck);
+	if (priv->soc_data->baseclk_is_generated_internally)
+		clk_base_rate = gck_rate / priv->soc_data->divider_for_baseclk;
+	else
+		clk_base_rate = clk_get_rate(priv->mainck);
+
+	clk_base = clk_base_rate / 1000000;
+	clk_mul = gck_rate / clk_base_rate - 1;
+
+	caps0 &= (~SDHCI_CLOCK_V3_BASE_MASK);
+	caps0 |= ((clk_base << SDHCI_CLOCK_BASE_SHIFT) & SDHCI_CLOCK_V3_BASE_MASK);
+	caps1 &= (~SDHCI_CLOCK_MUL_MASK);
+	caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK);
+	/* Set capabilities in r/w mode. */
+	writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);
+	writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
+	/* Set capabilities in ro mode. */
+	writel(0, host->ioaddr + SDMMC_CACR);
+
+	dev_info(dev, "update clk mul to %u as gck rate is %u Hz and clk base is %u Hz\n",
+		 clk_mul, gck_rate, clk_base_rate);
 
 	/*
 	 * We have to set preset values because it depends on the clk_mul
@@ -196,19 +201,19 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
 	 * maximum sd clock value is 120 MHz instead of 208 MHz. For that
 	 * reason, we need to use presets to support SDR104.
 	 */
-	preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1;
+	preset_div = DIV_ROUND_UP(gck_rate, 24000000) - 1;
 	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 	       host->ioaddr + SDHCI_PRESET_FOR_SDR12);
-	preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
+	preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
 	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 	       host->ioaddr + SDHCI_PRESET_FOR_SDR25);
-	preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1;
+	preset_div = DIV_ROUND_UP(gck_rate, 100000000) - 1;
 	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 	       host->ioaddr + SDHCI_PRESET_FOR_SDR50);
-	preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1;
+	preset_div = DIV_ROUND_UP(gck_rate, 120000000) - 1;
 	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 	       host->ioaddr + SDHCI_PRESET_FOR_SDR104);
-	preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
+	preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
 	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 	       host->ioaddr + SDHCI_PRESET_FOR_DDR50);
 
@@ -303,7 +308,7 @@ static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
 static int sdhci_at91_probe(struct platform_device *pdev)
 {
 	const struct of_device_id	*match;
-	const struct sdhci_pltfm_data	*soc_data;
+	const struct sdhci_at91_soc_data	*soc_data;
 	struct sdhci_host		*host;
 	struct sdhci_pltfm_host		*pltfm_host;
 	struct sdhci_at91_priv		*priv;
@@ -314,17 +319,22 @@ static int sdhci_at91_probe(struct platform_device *pdev)
 		return -EINVAL;
 	soc_data = match->data;
 
-	host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv));
+	host = sdhci_pltfm_init(pdev, soc_data->pdata, sizeof(*priv));
 	if (IS_ERR(host))
 		return PTR_ERR(host);
 
 	pltfm_host = sdhci_priv(host);
 	priv = sdhci_pltfm_priv(pltfm_host);
+	priv->soc_data = soc_data;
 
 	priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
 	if (IS_ERR(priv->mainck)) {
-		dev_err(&pdev->dev, "failed to get baseclk\n");
-		return PTR_ERR(priv->mainck);
+		if (soc_data->baseclk_is_generated_internally) {
+			priv->mainck = NULL;
+		} else {
+			dev_err(&pdev->dev, "failed to get baseclk\n");
+			return PTR_ERR(priv->mainck);
+		}
 	}
 
 	priv->hclock = devm_clk_get(&pdev->dev, "hclock");
-- 
2.23.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 3/3] ARM: dts: at91: sama5d2: set the sdmmc gclk frequency

[Ludovic Desroches]

Set the frequency of the generated clock used by sdmmc devices in order
to not rely on the configuration done by previous components.

Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
---
 arch/arm/boot/dts/sama5d2.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/sama5d2.dtsi b/arch/arm/boot/dts/sama5d2.dtsi
index 2e2c1a7b1d1d..8d79ff75e3cd 100644
--- a/arch/arm/boot/dts/sama5d2.dtsi
+++ b/arch/arm/boot/dts/sama5d2.dtsi
@@ -300,6 +300,8 @@
 			interrupts = <31 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&pmc PMC_TYPE_PERIPHERAL 31>, <&pmc PMC_TYPE_GCK 31>, <&pmc PMC_TYPE_CORE PMC_MAIN>;
 			clock-names = "hclock", "multclk", "baseclk";
+			assigned-clocks = <&pmc PMC_TYPE_GCK 31>;
+			assigned-clock-rates = <480000000>;
 			status = "disabled";
 		};
 
@@ -309,6 +311,8 @@
 			interrupts = <32 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&pmc PMC_TYPE_PERIPHERAL 32>, <&pmc PMC_TYPE_GCK 32>, <&pmc PMC_TYPE_CORE PMC_MAIN>;
 			clock-names = "hclock", "multclk", "baseclk";
+			assigned-clocks = <&pmc PMC_TYPE_GCK 32>;
+			assigned-clock-rates = <480000000>;
 			status = "disabled";
 		};
 
-- 
2.23.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 2/3] mmc: sdhci-of-at91: rework clocks management to support SAM9x60 device

[Eugen.Hristev]

On 12.09.2019 23:09, Ludovic Desroches wrote:

> 
> In the SAM9x60 SoC, there are only two clocks instead of three for the
> SDHCI device. The base clk is no longer provided, it is generated
> internally from the mult clk.
> 
> The values of the base clk and mul in the capabilities registers may not
> reflect the reality as the mult clk is a programmable clock which can take
> several rates. As we can't trust those values, take them from the clock
> tree and update the capabilities according to.
> 
> As we can have the same pitfall, in some cases, with the SAMA5D2 Soc,
> stop relying on capabilities too.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> ---
>   drivers/mmc/host/sdhci-of-at91.c | 104 +++++++++++++++++--------------
>   1 file changed, 57 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index e7d1920729fb..a9c126f14d85 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -30,7 +30,14 @@
>   
>   #define SDHCI_AT91_PRESET_COMMON_CONF	0x400 /* drv type B, programmable clock mode */
>   
> +struct sdhci_at91_soc_data {
> +	const struct sdhci_pltfm_data *pdata;
> +	bool baseclk_is_generated_internally;
> +	unsigned int divider_for_baseclk;
> +};
> +
>   struct sdhci_at91_priv {
> +	const struct sdhci_at91_soc_data *soc_data;
>   	struct clk *hclock;
>   	struct clk *gck;
>   	struct clk *mainck;
> @@ -130,12 +137,24 @@ static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
>   	.set_power		= sdhci_at91_set_power,
>   };
>   
> -static const struct sdhci_pltfm_data soc_data_sama5d2 = {
> +static const struct sdhci_pltfm_data sdhci_sama5d2_pdata = {
>   	.ops = &sdhci_at91_sama5d2_ops,
>   };
>   
> +static const struct sdhci_at91_soc_data soc_data_sama5d2 = {
> +	.pdata = &sdhci_sama5d2_pdata,
> +	.baseclk_is_generated_internally = false,
> +};
> +
> +static const struct sdhci_at91_soc_data soc_data_sam9x60 = {
> +	.pdata = &sdhci_sama5d2_pdata,
> +	.baseclk_is_generated_internally = true,
> +	.divider_for_baseclk = 2,
> +};
> +
>   static const struct of_device_id sdhci_at91_dt_match[] = {
>   	{ .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
> +	{ .compatible = "microchip,sam9x60-sdhci", .data = &soc_data_sam9x60 },
>   	{}
>   };
>   MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
> @@ -145,50 +164,36 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
>   	struct sdhci_host *host = dev_get_drvdata(dev);
>   	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>   	struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
> -	int ret;
>   	unsigned int			caps0, caps1;
>   	unsigned int			clk_base, clk_mul;
> -	unsigned int			gck_rate, real_gck_rate;
> +	unsigned int			gck_rate, clk_base_rate;
>   	unsigned int			preset_div;
>   
> -	/*
> -	 * The mult clock is provided by as a generated clock by the PMC
> -	 * controller. In order to set the rate of gck, we have to get the
> -	 * base clock rate and the clock mult from capabilities.
> -	 */
>   	clk_prepare_enable(priv->hclock);
>   	caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
>   	caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
> -	clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
> -	clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
> -	gck_rate = clk_base * 1000000 * (clk_mul + 1);
> -	ret = clk_set_rate(priv->gck, gck_rate);
> -	if (ret < 0) {
> -		dev_err(dev, "failed to set gck");
> -		clk_disable_unprepare(priv->hclock);
> -		return ret;
> -	}
> -	/*
> -	 * We need to check if we have the requested rate for gck because in
> -	 * some cases this rate could be not supported. If it happens, the rate
> -	 * is the closest one gck can provide. We have to update the value
> -	 * of clk mul.
> -	 */
> -	real_gck_rate = clk_get_rate(priv->gck);
> -	if (real_gck_rate != gck_rate) {
> -		clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
> -		caps1 &= (~SDHCI_CLOCK_MUL_MASK);
> -		caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) &
> -			  SDHCI_CLOCK_MUL_MASK);
> -		/* Set capabilities in r/w mode. */
> -		writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN,
> -		       host->ioaddr + SDMMC_CACR);
> -		writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
> -		/* Set capabilities in ro mode. */
> -		writel(0, host->ioaddr + SDMMC_CACR);
> -		dev_info(dev, "update clk mul to %u as gck rate is %u Hz\n",
> -			 clk_mul, real_gck_rate);
> -	}
> +
> +	gck_rate = clk_get_rate(priv->gck);
> +	if (priv->soc_data->baseclk_is_generated_internally)
> +		clk_base_rate = gck_rate / priv->soc_data->divider_for_baseclk;
> +	else
> +		clk_base_rate = clk_get_rate(priv->mainck);
> +
> +	clk_base = clk_base_rate / 1000000;
> +	clk_mul = gck_rate / clk_base_rate - 1;
> +
> +	caps0 &= (~SDHCI_CLOCK_V3_BASE_MASK);
> +	caps0 |= ((clk_base << SDHCI_CLOCK_BASE_SHIFT) & SDHCI_CLOCK_V3_BASE_MASK);
> +	caps1 &= (~SDHCI_CLOCK_MUL_MASK);
> +	caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK);
> +	/* Set capabilities in r/w mode. */
> +	writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);

Hi Ludovic,

I have a feeling that here you may wish to also write the caps0 to the 
SDHC_CAPABILITIES:
writel(caps0, host->ioaddr + SDHCI_CAPABILITIES);

You are computing the caps0 but not writing them to register.

Eugen

> +	writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
> +	/* Set capabilities in ro mode. */
> +	writel(0, host->ioaddr + SDMMC_CACR);
> +
> +	dev_info(dev, "update clk mul to %u as gck rate is %u Hz and clk base is %u Hz\n",
> +		 clk_mul, gck_rate, clk_base_rate);
>   
>   	/*
>   	 * We have to set preset values because it depends on the clk_mul
> @@ -196,19 +201,19 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
>   	 * maximum sd clock value is 120 MHz instead of 208 MHz. For that
>   	 * reason, we need to use presets to support SDR104.
>   	 */
> -	preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1;
> +	preset_div = DIV_ROUND_UP(gck_rate, 24000000) - 1;
>   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
>   	       host->ioaddr + SDHCI_PRESET_FOR_SDR12);
> -	preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> +	preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
>   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
>   	       host->ioaddr + SDHCI_PRESET_FOR_SDR25);
> -	preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1;
> +	preset_div = DIV_ROUND_UP(gck_rate, 100000000) - 1;
>   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
>   	       host->ioaddr + SDHCI_PRESET_FOR_SDR50);
> -	preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1;
> +	preset_div = DIV_ROUND_UP(gck_rate, 120000000) - 1;
>   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
>   	       host->ioaddr + SDHCI_PRESET_FOR_SDR104);
> -	preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> +	preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
>   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
>   	       host->ioaddr + SDHCI_PRESET_FOR_DDR50);
>   
> @@ -303,7 +308,7 @@ static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
>   static int sdhci_at91_probe(struct platform_device *pdev)
>   {
>   	const struct of_device_id	*match;
> -	const struct sdhci_pltfm_data	*soc_data;
> +	const struct sdhci_at91_soc_data	*soc_data;
>   	struct sdhci_host		*host;
>   	struct sdhci_pltfm_host		*pltfm_host;
>   	struct sdhci_at91_priv		*priv;
> @@ -314,17 +319,22 @@ static int sdhci_at91_probe(struct platform_device *pdev)
>   		return -EINVAL;
>   	soc_data = match->data;
>   
> -	host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv));
> +	host = sdhci_pltfm_init(pdev, soc_data->pdata, sizeof(*priv));
>   	if (IS_ERR(host))
>   		return PTR_ERR(host);
>   
>   	pltfm_host = sdhci_priv(host);
>   	priv = sdhci_pltfm_priv(pltfm_host);
> +	priv->soc_data = soc_data;
>   
>   	priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
>   	if (IS_ERR(priv->mainck)) {
> -		dev_err(&pdev->dev, "failed to get baseclk\n");
> -		return PTR_ERR(priv->mainck);
> +		if (soc_data->baseclk_is_generated_internally) {
> +			priv->mainck = NULL;
> +		} else {
> +			dev_err(&pdev->dev, "failed to get baseclk\n");
> +			return PTR_ERR(priv->mainck);
> +		}
>   	}
>   
>   	priv->hclock = devm_clk_get(&pdev->dev, "hclock");
> 
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/3] dt-bindings: sdhci-of-at91: new compatible string and update properties

[Rob Herring]

On Thu, Sep 12, 2019 at 10:09:06PM +0200, Ludovic Desroches wrote:
> There is a new compatible string for the SAM9X60 sdhci device. It involves
> an update of the properties about the clocks stuff.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> ---
>  .../devicetree/bindings/mmc/sdhci-atmel.txt   | 25 ++++++++++++++++---
>  1 file changed, 22 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
> index 1b662d7171a0..364ceea330b6 100644
> --- a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
> +++ b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
> @@ -5,12 +5,19 @@ Documentation/devicetree/bindings/mmc/mmc.txt and the properties used by the
>  sdhci-of-at91 driver.
>  
>  Required properties:
> -- compatible:		Must be "atmel,sama5d2-sdhci".
> +- compatible:		Must be "atmel,sama5d2-sdhci" or "microchip,sam9x60-sdhci".
>  - clocks:		Phandlers to the clocks.
> -- clock-names:		Must be "hclock", "multclk", "baseclk";
> +- clock-names:		Must be "hclock", "multclk", "baseclk" for
> +			"atmel,sama5d2-sdhci".
> +			Must be "hclock", "multclk" for "microchip,sam9x60-sdhci".
>  
> +Optional properties:
> +- assigned-clocks:	The same with "multclk".
> +- assigned-clock-rates	The rate of "multclk" in order to not rely on the
> +			gck configuration set by previous components.
>  
> -Example:
> +
> +Examples:
>  
>  sdmmc0: sdio-host@a0000000 {
>  	compatible = "atmel,sama5d2-sdhci";
> @@ -18,4 +25,16 @@ sdmmc0: sdio-host@a0000000 {
>  	interrupts = <31 IRQ_TYPE_LEVEL_HIGH 0>;
>  	clocks = <&sdmmc0_hclk>, <&sdmmc0_gclk>, <&main>;
>  	clock-names = "hclock", "multclk", "baseclk";
> +	assigned-clocks = <&sdmmc0_gclk>;
> +	assigned-clock-rates = <480000000>;
> +};
> +
> +sdmmc0: sdio-host@80000000 {

mmc@...

Though I don't see much value in a second example. Examples are not a 
complete enumeration of all possible dts entries.

> +	compatible = "microchip,sam9x60-sdhci";
> +	reg = <0x80000000 0x300>;
> +	interrupts = <12 IRQ_TYPE_LEVEL_HIGH 0>;
> +	clocks = <&pmc PMC_TYPE_PERIPHERAL 12>, <&pmc PMC_TYPE_GCK 12>;
> +	clock-names = "hclock", "multclk";
> +	assigned-clocks = <&pmc PMC_TYPE_GCK 12>;
> +	assigned-clock-rates = <100000000>;
>  };
> -- 
> 2.23.0
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 2/3] mmc: sdhci-of-at91: rework clocks management to support SAM9x60 device

[Ludovic Desroches]

On Fri, Sep 20, 2019 at 11:34:50AM +0200, Eugen Hristev - M18282 wrote:
> 
> 
> On 12.09.2019 23:09, Ludovic Desroches wrote:
> 
> > 
> > In the SAM9x60 SoC, there are only two clocks instead of three for the
> > SDHCI device. The base clk is no longer provided, it is generated
> > internally from the mult clk.
> > 
> > The values of the base clk and mul in the capabilities registers may not
> > reflect the reality as the mult clk is a programmable clock which can take
> > several rates. As we can't trust those values, take them from the clock
> > tree and update the capabilities according to.
> > 
> > As we can have the same pitfall, in some cases, with the SAMA5D2 Soc,
> > stop relying on capabilities too.
> > 
> > Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> > ---
> >   drivers/mmc/host/sdhci-of-at91.c | 104 +++++++++++++++++--------------
> >   1 file changed, 57 insertions(+), 47 deletions(-)
> > 
> > diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> > index e7d1920729fb..a9c126f14d85 100644
> > --- a/drivers/mmc/host/sdhci-of-at91.c
> > +++ b/drivers/mmc/host/sdhci-of-at91.c
> > @@ -30,7 +30,14 @@
> >   
> >   #define SDHCI_AT91_PRESET_COMMON_CONF	0x400 /* drv type B, programmable clock mode */
> >   
> > +struct sdhci_at91_soc_data {
> > +	const struct sdhci_pltfm_data *pdata;
> > +	bool baseclk_is_generated_internally;
> > +	unsigned int divider_for_baseclk;
> > +};
> > +
> >   struct sdhci_at91_priv {
> > +	const struct sdhci_at91_soc_data *soc_data;
> >   	struct clk *hclock;
> >   	struct clk *gck;
> >   	struct clk *mainck;
> > @@ -130,12 +137,24 @@ static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
> >   	.set_power		= sdhci_at91_set_power,
> >   };
> >   
> > -static const struct sdhci_pltfm_data soc_data_sama5d2 = {
> > +static const struct sdhci_pltfm_data sdhci_sama5d2_pdata = {
> >   	.ops = &sdhci_at91_sama5d2_ops,
> >   };
> >   
> > +static const struct sdhci_at91_soc_data soc_data_sama5d2 = {
> > +	.pdata = &sdhci_sama5d2_pdata,
> > +	.baseclk_is_generated_internally = false,
> > +};
> > +
> > +static const struct sdhci_at91_soc_data soc_data_sam9x60 = {
> > +	.pdata = &sdhci_sama5d2_pdata,
> > +	.baseclk_is_generated_internally = true,
> > +	.divider_for_baseclk = 2,
> > +};
> > +
> >   static const struct of_device_id sdhci_at91_dt_match[] = {
> >   	{ .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
> > +	{ .compatible = "microchip,sam9x60-sdhci", .data = &soc_data_sam9x60 },
> >   	{}
> >   };
> >   MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
> > @@ -145,50 +164,36 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
> >   	struct sdhci_host *host = dev_get_drvdata(dev);
> >   	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> >   	struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
> > -	int ret;
> >   	unsigned int			caps0, caps1;
> >   	unsigned int			clk_base, clk_mul;
> > -	unsigned int			gck_rate, real_gck_rate;
> > +	unsigned int			gck_rate, clk_base_rate;
> >   	unsigned int			preset_div;
> >   
> > -	/*
> > -	 * The mult clock is provided by as a generated clock by the PMC
> > -	 * controller. In order to set the rate of gck, we have to get the
> > -	 * base clock rate and the clock mult from capabilities.
> > -	 */
> >   	clk_prepare_enable(priv->hclock);
> >   	caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
> >   	caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
> > -	clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
> > -	clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
> > -	gck_rate = clk_base * 1000000 * (clk_mul + 1);
> > -	ret = clk_set_rate(priv->gck, gck_rate);
> > -	if (ret < 0) {
> > -		dev_err(dev, "failed to set gck");
> > -		clk_disable_unprepare(priv->hclock);
> > -		return ret;
> > -	}
> > -	/*
> > -	 * We need to check if we have the requested rate for gck because in
> > -	 * some cases this rate could be not supported. If it happens, the rate
> > -	 * is the closest one gck can provide. We have to update the value
> > -	 * of clk mul.
> > -	 */
> > -	real_gck_rate = clk_get_rate(priv->gck);
> > -	if (real_gck_rate != gck_rate) {
> > -		clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
> > -		caps1 &= (~SDHCI_CLOCK_MUL_MASK);
> > -		caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) &
> > -			  SDHCI_CLOCK_MUL_MASK);
> > -		/* Set capabilities in r/w mode. */
> > -		writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN,
> > -		       host->ioaddr + SDMMC_CACR);
> > -		writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
> > -		/* Set capabilities in ro mode. */
> > -		writel(0, host->ioaddr + SDMMC_CACR);
> > -		dev_info(dev, "update clk mul to %u as gck rate is %u Hz\n",
> > -			 clk_mul, real_gck_rate);
> > -	}
> > +
> > +	gck_rate = clk_get_rate(priv->gck);
> > +	if (priv->soc_data->baseclk_is_generated_internally)
> > +		clk_base_rate = gck_rate / priv->soc_data->divider_for_baseclk;
> > +	else
> > +		clk_base_rate = clk_get_rate(priv->mainck);
> > +
> > +	clk_base = clk_base_rate / 1000000;
> > +	clk_mul = gck_rate / clk_base_rate - 1;
> > +
> > +	caps0 &= (~SDHCI_CLOCK_V3_BASE_MASK);
> > +	caps0 |= ((clk_base << SDHCI_CLOCK_BASE_SHIFT) & SDHCI_CLOCK_V3_BASE_MASK);
> > +	caps1 &= (~SDHCI_CLOCK_MUL_MASK);
> > +	caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK);
> > +	/* Set capabilities in r/w mode. */
> > +	writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);
> 
> Hi Ludovic,
> 
> I have a feeling that here you may wish to also write the caps0 to the 
> SDHC_CAPABILITIES:
> writel(caps0, host->ioaddr + SDHCI_CAPABILITIES);
> 
> You are computing the caps0 but not writing them to register.

Hi Eugen,

It slipped through the net as it didn't cause error when I tested it.
Thanks, I'll fix it.

Ludovic

> 
> Eugen
> 
> > +	writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
> > +	/* Set capabilities in ro mode. */
> > +	writel(0, host->ioaddr + SDMMC_CACR);
> > +
> > +	dev_info(dev, "update clk mul to %u as gck rate is %u Hz and clk base is %u Hz\n",
> > +		 clk_mul, gck_rate, clk_base_rate);
> >   
> >   	/*
> >   	 * We have to set preset values because it depends on the clk_mul
> > @@ -196,19 +201,19 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
> >   	 * maximum sd clock value is 120 MHz instead of 208 MHz. For that
> >   	 * reason, we need to use presets to support SDR104.
> >   	 */
> > -	preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1;
> > +	preset_div = DIV_ROUND_UP(gck_rate, 24000000) - 1;
> >   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> >   	       host->ioaddr + SDHCI_PRESET_FOR_SDR12);
> > -	preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> > +	preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
> >   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> >   	       host->ioaddr + SDHCI_PRESET_FOR_SDR25);
> > -	preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1;
> > +	preset_div = DIV_ROUND_UP(gck_rate, 100000000) - 1;
> >   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> >   	       host->ioaddr + SDHCI_PRESET_FOR_SDR50);
> > -	preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1;
> > +	preset_div = DIV_ROUND_UP(gck_rate, 120000000) - 1;
> >   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> >   	       host->ioaddr + SDHCI_PRESET_FOR_SDR104);
> > -	preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> > +	preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
> >   	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> >   	       host->ioaddr + SDHCI_PRESET_FOR_DDR50);
> >   
> > @@ -303,7 +308,7 @@ static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
> >   static int sdhci_at91_probe(struct platform_device *pdev)
> >   {
> >   	const struct of_device_id	*match;
> > -	const struct sdhci_pltfm_data	*soc_data;
> > +	const struct sdhci_at91_soc_data	*soc_data;
> >   	struct sdhci_host		*host;
> >   	struct sdhci_pltfm_host		*pltfm_host;
> >   	struct sdhci_at91_priv		*priv;
> > @@ -314,17 +319,22 @@ static int sdhci_at91_probe(struct platform_device *pdev)
> >   		return -EINVAL;
> >   	soc_data = match->data;
> >   
> > -	host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv));
> > +	host = sdhci_pltfm_init(pdev, soc_data->pdata, sizeof(*priv));
> >   	if (IS_ERR(host))
> >   		return PTR_ERR(host);
> >   
> >   	pltfm_host = sdhci_priv(host);
> >   	priv = sdhci_pltfm_priv(pltfm_host);
> > +	priv->soc_data = soc_data;
> >   
> >   	priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
> >   	if (IS_ERR(priv->mainck)) {
> > -		dev_err(&pdev->dev, "failed to get baseclk\n");
> > -		return PTR_ERR(priv->mainck);
> > +		if (soc_data->baseclk_is_generated_internally) {
> > +			priv->mainck = NULL;
> > +		} else {
> > +			dev_err(&pdev->dev, "failed to get baseclk\n");
> > +			return PTR_ERR(priv->mainck);
> > +		}
> >   	}
> >   
> >   	priv->hclock = devm_clk_get(&pdev->dev, "hclock");
> > 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/3] dt-bindings: sdhci-of-at91: new compatible string and update properties

[Ludovic Desroches]

On Mon, Sep 30, 2019 at 09:56:13AM -0500, Rob Herring wrote:
> On Thu, Sep 12, 2019 at 10:09:06PM +0200, Ludovic Desroches wrote:
> > There is a new compatible string for the SAM9X60 sdhci device. It involves
> > an update of the properties about the clocks stuff.
> > 
> > Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> > ---
> >  .../devicetree/bindings/mmc/sdhci-atmel.txt   | 25 ++++++++++++++++---
> >  1 file changed, 22 insertions(+), 3 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
> > index 1b662d7171a0..364ceea330b6 100644
> > --- a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
> > +++ b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
> > @@ -5,12 +5,19 @@ Documentation/devicetree/bindings/mmc/mmc.txt and the properties used by the
> >  sdhci-of-at91 driver.
> >  
> >  Required properties:
> > -- compatible:		Must be "atmel,sama5d2-sdhci".
> > +- compatible:		Must be "atmel,sama5d2-sdhci" or "microchip,sam9x60-sdhci".
> >  - clocks:		Phandlers to the clocks.
> > -- clock-names:		Must be "hclock", "multclk", "baseclk";
> > +- clock-names:		Must be "hclock", "multclk", "baseclk" for
> > +			"atmel,sama5d2-sdhci".
> > +			Must be "hclock", "multclk" for "microchip,sam9x60-sdhci".
> >  
> > +Optional properties:
> > +- assigned-clocks:	The same with "multclk".
> > +- assigned-clock-rates	The rate of "multclk" in order to not rely on the
> > +			gck configuration set by previous components.
> >  
> > -Example:
> > +
> > +Examples:
> >  
> >  sdmmc0: sdio-host@a0000000 {
> >  	compatible = "atmel,sama5d2-sdhci";
> > @@ -18,4 +25,16 @@ sdmmc0: sdio-host@a0000000 {
> >  	interrupts = <31 IRQ_TYPE_LEVEL_HIGH 0>;
> >  	clocks = <&sdmmc0_hclk>, <&sdmmc0_gclk>, <&main>;
> >  	clock-names = "hclock", "multclk", "baseclk";
> > +	assigned-clocks = <&sdmmc0_gclk>;
> > +	assigned-clock-rates = <480000000>;
> > +};
> > +
> > +sdmmc0: sdio-host@80000000 {
> 
> mmc@...
> 
> Though I don't see much value in a second example. Examples are not a 
> complete enumeration of all possible dts entries.
> 

Ok, I'll skip this example.

Ludovic

> > +	compatible = "microchip,sam9x60-sdhci";
> > +	reg = <0x80000000 0x300>;
> > +	interrupts = <12 IRQ_TYPE_LEVEL_HIGH 0>;
> > +	clocks = <&pmc PMC_TYPE_PERIPHERAL 12>, <&pmc PMC_TYPE_GCK 12>;
> > +	clock-names = "hclock", "multclk";
> > +	assigned-clocks = <&pmc PMC_TYPE_GCK 12>;
> > +	assigned-clock-rates = <100000000>;
> >  };
> > -- 
> > 2.23.0
> > 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel