Commit c8a019e7 authored by Quentin Schulz's avatar Quentin Schulz Committed by Ulf Hansson
Browse files

mmc: sdhci-of-at91: factor out clks and presets setting 



The setting of clocks and presets is currently done in probe only but
once deep PM support is added, it'll be needed in the resume function.

Let's create a function for this setting.

Signed-off-by: default avatarQuentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: default avatarLudovic Desroches <ludovic.desroches@microchip.com>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 62b1ab2a

drivers/mmc/host/sdhci-of-at91.c

+82 −65
Original line number Diff line number Diff line
@@ -146,6 +146,84 @@ static const struct of_device_id sdhci_at91_dt_match[] = { 
};

MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);



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			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);

	}



	/*

	 * We have to set preset values because it depends on the clk_mul

	 * value. Moreover, SDR104 is supported in a degraded mode since the

	 * 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;

	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,

	       host->ioaddr + SDHCI_PRESET_FOR_SDR12);

	preset_div = DIV_ROUND_UP(real_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;

	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,

	       host->ioaddr + SDHCI_PRESET_FOR_SDR50);

	preset_div = DIV_ROUND_UP(real_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;

	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,

	       host->ioaddr + SDHCI_PRESET_FOR_DDR50);



	clk_prepare_enable(priv->mainck);

	clk_prepare_enable(priv->gck);



	return 0;

}



#ifdef CONFIG_PM

static int sdhci_at91_runtime_suspend(struct device *dev)

{
@@ -210,11 +288,7 @@ static int sdhci_at91_probe(struct platform_device *pdev) 
	struct sdhci_host		*host;

	struct sdhci_pltfm_host		*pltfm_host;

	struct sdhci_at91_priv		*priv;

	unsigned int			caps0, caps1;

	unsigned int			clk_base, clk_mul;

	unsigned int			gck_rate, real_gck_rate;

	int				ret;

	unsigned int			preset_div;



	match = of_match_device(sdhci_at91_dt_match, &pdev->dev);

	if (!match)
@@ -246,66 +320,9 @@ static int sdhci_at91_probe(struct platform_device *pdev) 
		return PTR_ERR(priv->gck);

	}



	/*

	 * 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(&pdev->dev, "failed to set gck");

		goto hclock_disable_unprepare;

	}

	/*

	 * 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(&pdev->dev, "update clk mul to %u as gck rate is %u Hz\n",

			 clk_mul, real_gck_rate);

	}



	/*

	 * We have to set preset values because it depends on the clk_mul

	 * value. Moreover, SDR104 is supported in a degraded mode since the

	 * 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;

	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,

	       host->ioaddr + SDHCI_PRESET_FOR_SDR12);

	preset_div = DIV_ROUND_UP(real_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;

	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,

	       host->ioaddr + SDHCI_PRESET_FOR_SDR50);

	preset_div = DIV_ROUND_UP(real_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;

	writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,

	       host->ioaddr + SDHCI_PRESET_FOR_DDR50);



	clk_prepare_enable(priv->mainck);

	clk_prepare_enable(priv->gck);

	ret = sdhci_at91_set_clks_presets(&pdev->dev);

	if (ret)

		goto sdhci_pltfm_free;



	ret = mmc_of_parse(host->mmc);

	if (ret)
@@ -368,8 +385,8 @@ static int sdhci_at91_probe(struct platform_device *pdev) 
clocks_disable_unprepare:

	clk_disable_unprepare(priv->gck);

	clk_disable_unprepare(priv->mainck);

hclock_disable_unprepare:

	clk_disable_unprepare(priv->hclock);

sdhci_pltfm_free:

	sdhci_pltfm_free(pdev);

	return ret;

}