Commit eb250826 authored by David Brownell's avatar David Brownell Committed by Pierre Ossman
Browse files

omap_hsmmc: only MMC1 allows HCTL.SDVS != 1.8V 



Based on a patch from Tony Lindgren ... after initialization,
never change HCTL.SDVS except for MMC1.  The other controller
instances only support 1.8V in that field, although they can
suport other card/SDIO/eMMC/... voltages with level shifting
solutions such as external transceivers.

MMC2 behavior sanity tested on Overo/WLAN, OMAP3430 SDP, and
custom hardware.  MMC1 also sanity tested on those platforms
plus Beagle.  This also fixes a bug preventing MMC2 (and also
presumably MMC3) from powering down when requested.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 249d0fa9

drivers/mmc/host/omap_hsmmc.c

+33 −10
Original line number Diff line number Diff line
@@ -55,6 +55,7 @@ 
#define VS30			(1 << 25)

#define SDVS18			(0x5 << 9)

#define SDVS30			(0x6 << 9)

#define SDVS33			(0x7 << 9)

#define SDVSCLR			0xFFFFF1FF

#define SDVSDET			0x00000400

#define AUTOIDLE		0x1
@@ -456,13 +457,20 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id) 
}



/*

 * Switch MMC operating voltage

 * Switch MMC interface voltage ... only relevant for MMC1.

 *

 * MMC2 and MMC3 use fixed 1.8V levels, and maybe a transceiver.

 * The MMC2 transceiver controls are used instead of DAT4..DAT7.

 * Some chips, like eMMC ones, use internal transceivers.

 */

static int omap_mmc_switch_opcond(struct mmc_omap_host *host, int vdd)

{

	u32 reg_val = 0;

	int ret;



	if (host->id != OMAP_MMC1_DEVID)

		return 0;



	/* Disable the clocks */

	clk_disable(host->fclk);

	clk_disable(host->iclk);
@@ -485,19 +493,26 @@ static int omap_mmc_switch_opcond(struct mmc_omap_host *host, int vdd) 
	OMAP_HSMMC_WRITE(host->base, HCTL,

		OMAP_HSMMC_READ(host->base, HCTL) & SDVSCLR);

	reg_val = OMAP_HSMMC_READ(host->base, HCTL);



	/*

	 * If a MMC dual voltage card is detected, the set_ios fn calls

	 * this fn with VDD bit set for 1.8V. Upon card removal from the

	 * slot, omap_mmc_set_ios sets the VDD back to 3V on MMC_POWER_OFF.

	 *

	 * Only MMC1 supports 3.0V.  MMC2 will not function if SDVS30 is

	 * set in HCTL.

	 * Cope with a bit of slop in the range ... per data sheets:

	 *  - "1.8V" for vdds_mmc1/vdds_mmc1a can be up to 2.45V max,

	 *    but recommended values are 1.71V to 1.89V

	 *  - "3.0V" for vdds_mmc1/vdds_mmc1a can be up to 3.5V max,

	 *    but recommended values are 2.7V to 3.3V

	 *

	 * Board setup code shouldn't permit anything very out-of-range.

	 * TWL4030-family VMMC1 and VSIM regulators are fine (avoiding the

	 * middle range) but VSIM can't power DAT4..DAT7 at more than 3V.

	 */

	if (host->id == OMAP_MMC1_DEVID && (((1 << vdd) == MMC_VDD_32_33) ||

				((1 << vdd) == MMC_VDD_33_34)))

		reg_val |= SDVS30;

	if ((1 << vdd) == MMC_VDD_165_195)

	if ((1 << vdd) <= MMC_VDD_23_24)

		reg_val |= SDVS18;

	else

		reg_val |= SDVS30;



	OMAP_HSMMC_WRITE(host->base, HCTL, reg_val);
@@ -759,10 +774,14 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) 
	case MMC_POWER_OFF:

		mmc_slot(host).set_power(host->dev, host->slot_id, 0, 0);

		/*

		 * Reset bus voltage to 3V if it got set to 1.8V earlier.

		 * Reset interface voltage to 3V if it's 1.8V now;

		 * only relevant on MMC-1, the others always use 1.8V.

		 *

		 * REVISIT: If we are able to detect cards after unplugging

		 * a 1.8V card, this code should not be needed.

		 */

		if (host->id != OMAP_MMC1_DEVID)

			break;

		if (!(OMAP_HSMMC_READ(host->base, HCTL) & SDVSDET)) {

			int vdd = fls(host->mmc->ocr_avail) - 1;

			if (omap_mmc_switch_opcond(host, vdd) != 0)
@@ -786,7 +805,9 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) 
	}



	if (host->id == OMAP_MMC1_DEVID) {

		/* Only MMC1 can operate at 3V/1.8V */

		/* Only MMC1 can interface at 3V without some flavor

		 * of external transceiver; but they all handle 1.8V.

		 */

		if ((OMAP_HSMMC_READ(host->base, HCTL) & SDVSDET) &&

			(ios->vdd == DUAL_VOLT_OCR_BIT)) {

				/*
@@ -1139,7 +1160,9 @@ static int omap_mmc_suspend(struct platform_device *pdev, pm_message_t state) 
						" level suspend\n");

			}



			if (!(OMAP_HSMMC_READ(host->base, HCTL) & SDVSDET)) {

			if (host->id == OMAP_MMC1_DEVID

					&& !(OMAP_HSMMC_READ(host->base, HCTL)

							& SDVSDET)) {

				OMAP_HSMMC_WRITE(host->base, HCTL,

					OMAP_HSMMC_READ(host->base, HCTL)

					& SDVSCLR);

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