From eb25082657be3e7639e349fc926afdcbb0a4dc65 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Tue, 17 Feb 2009 14:49:01 -0800 Subject: [PATCH] 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: David Brownell Acked-by: Tony Lindgren Signed-off-by: Pierre Ossman --- drivers/mmc/host/omap_hsmmc.c | 43 +++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 10 deletions(-) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 4dba48642e6..3bfd0facb79 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -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); -- 2.41.1