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Commit 6231f3de authored by Philip Rakity's avatar Philip Rakity Committed by Chris Ball
Browse files

mmc: sdhci: Add regulator support for vccq (voltage regualor) 



On some systems the host controller does not support vccq
signaling.  This is supplied by a dedicated regulator (vqmmc).
Add support for this regulator.

Signed-off-by: default avatarPhilip Rakity <prakity@marvell.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 137ccd46

drivers/mmc/host/sdhci.c

+116 −65
Original line number Diff line number Diff line
@@ -1597,30 +1597,23 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable) 
	spin_unlock_irqrestore(&host->lock, flags);

}



static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host,

						struct mmc_ios *ios)

static int sdhci_do_3_3v_signal_voltage_switch(struct sdhci_host *host,

						u16 ctrl)

{

	u8 pwr;

	u16 clk, ctrl;

	u32 present_state;



	/*

	 * Signal Voltage Switching is only applicable for Host Controllers

	 * v3.00 and above.

	 */

	if (host->version < SDHCI_SPEC_300)

		return 0;

	int ret;



	/*

	 * We first check whether the request is to set signalling voltage

	 * to 3.3V. If so, we change the voltage to 3.3V and return quickly.

	 */

	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {

	/* Set 1.8V Signal Enable in the Host Control2 register to 0 */

	ctrl &= ~SDHCI_CTRL_VDD_180;

	sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);



	if (host->vqmmc) {

		ret = regulator_set_voltage(host->vqmmc, 3300000, 3300000);

		if (ret) {

			pr_warning("%s: Switching to 3.3V signalling voltage "

				   " failed\n", mmc_hostname(host->mmc));

			return -EIO;

		}

	}

	/* Wait for 5ms */

	usleep_range(5000, 5500);
@@ -1628,13 +1621,21 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, 
	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

	if (!(ctrl & SDHCI_CTRL_VDD_180))

		return 0;

		else {

			pr_info(DRIVER_NAME ": Switching to 3.3V "

				"signalling voltage failed\n");



	pr_warning("%s: 3.3V regulator output did not became stable\n",

		   mmc_hostname(host->mmc));



	return -EIO;

}

	} else if (!(ctrl & SDHCI_CTRL_VDD_180) &&

		  (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)) {



static int sdhci_do_1_8v_signal_voltage_switch(struct sdhci_host *host,

						u16 ctrl)

{

	u8 pwr;

	u16 clk;

	u32 present_state;

	int ret;



	/* Stop SDCLK */

	clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);

	clk &= ~SDHCI_CLOCK_CARD_EN;
@@ -1648,6 +1649,13 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, 
		 * Enable 1.8V Signal Enable in the Host Control2

		 * register

		 */

		if (host->vqmmc)

			ret = regulator_set_voltage(host->vqmmc,

				1800000, 1800000);

		else

			ret = 0;



		if (!ret) {

			ctrl |= SDHCI_CTRL_VDD_180;

			sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
@@ -1673,6 +1681,7 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, 
					return 0;

			}

		}

	}



	/*

	 * If we are here, that means the switch to 1.8V signaling
@@ -1692,10 +1701,35 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, 
	if (host->vmmc)

		regulator_enable(host->vmmc);



		pr_info(DRIVER_NAME ": Switching to 1.8V signalling "

			"voltage failed, retrying with S18R set to 0\n");

	pr_warning("%s: Switching to 1.8V signalling voltage failed, "

		   "retrying with S18R set to 0\n", mmc_hostname(host->mmc));



	return -EAGAIN;

	} else

}



static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host,

						struct mmc_ios *ios)

{

	u16 ctrl;



	/*

	 * Signal Voltage Switching is only applicable for Host Controllers

	 * v3.00 and above.

	 */

	if (host->version < SDHCI_SPEC_300)

		return 0;



	/*

	 * We first check whether the request is to set signalling voltage

	 * to 3.3V. If so, we change the voltage to 3.3V and return quickly.

	 */

	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)

		return sdhci_do_3_3v_signal_voltage_switch(host, ctrl);

	else if (!(ctrl & SDHCI_CTRL_VDD_180) &&

			(ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180))

		return sdhci_do_1_8v_signal_voltage_switch(host, ctrl);

	else

		/* No signal voltage switch required */

		return 0;

}
@@ -2802,6 +2836,18 @@ int sdhci_add_host(struct sdhci_host *host) 
	    !(host->mmc->caps & MMC_CAP_NONREMOVABLE))

		mmc->caps |= MMC_CAP_NEEDS_POLL;



	/* If vqmmc regulator and no 1.8V signalling, then there's no UHS */

	host->vqmmc = regulator_get(mmc_dev(mmc), "vqmmc");

	if (IS_ERR(host->vqmmc)) {

		pr_info("%s: no vqmmc regulator found\n", mmc_hostname(mmc));

		host->vqmmc = NULL;

	}

	else if (regulator_is_supported_voltage(host->vqmmc, 1800000, 1800000))

		regulator_enable(host->vqmmc);

	else

		caps[1] &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |

		       SDHCI_SUPPORT_DDR50);



	/* Any UHS-I mode in caps implies SDR12 and SDR25 support. */

	if (caps[1] & (SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |

		       SDHCI_SUPPORT_DDR50))
@@ -3122,6 +3168,11 @@ void sdhci_remove_host(struct sdhci_host *host, int dead) 
	if (host->vmmc)

		regulator_put(host->vmmc);



	if (host->vqmmc) {

		regulator_disable(host->vqmmc);

		regulator_put(host->vqmmc);

	}



	kfree(host->adma_desc);

	kfree(host->align_buffer);

include/linux/mmc/sdhci.h

+2 −1
Original line number Diff line number Diff line
@@ -97,7 +97,8 @@ struct sdhci_host { 


	const struct sdhci_ops *ops;	/* Low level hw interface */



	struct regulator *vmmc;	/* Power regulator */

	struct regulator *vmmc;		/* Power regulator (vmmc) */

	struct regulator *vqmmc;	/* Signaling regulator (vccq) */



	/* Internal data */

	struct mmc_host *mmc;	/* MMC structure */