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path: root/drivers/mmc/host/omap_hsmmc.c
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Diffstat (limited to 'drivers/mmc/host/omap_hsmmc.c')
-rw-r--r--drivers/mmc/host/omap_hsmmc.c98
1 files changed, 68 insertions, 30 deletions
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index db37490f67ec..a631c81dce12 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
@@ -375,6 +376,32 @@ static void mmc_omap_report_irq(struct mmc_omap_host *host, u32 status)
}
#endif /* CONFIG_MMC_DEBUG */
+/*
+ * MMC controller internal state machines reset
+ *
+ * Used to reset command or data internal state machines, using respectively
+ * SRC or SRD bit of SYSCTL register
+ * Can be called from interrupt context
+ */
+static inline void mmc_omap_reset_controller_fsm(struct mmc_omap_host *host,
+ unsigned long bit)
+{
+ unsigned long i = 0;
+ unsigned long limit = (loops_per_jiffy *
+ msecs_to_jiffies(MMC_TIMEOUT_MS));
+
+ OMAP_HSMMC_WRITE(host->base, SYSCTL,
+ OMAP_HSMMC_READ(host->base, SYSCTL) | bit);
+
+ while ((OMAP_HSMMC_READ(host->base, SYSCTL) & bit) &&
+ (i++ < limit))
+ cpu_relax();
+
+ if (OMAP_HSMMC_READ(host->base, SYSCTL) & bit)
+ dev_err(mmc_dev(host->mmc),
+ "Timeout waiting on controller reset in %s\n",
+ __func__);
+}
/*
* MMC controller IRQ handler
@@ -403,21 +430,17 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
(status & CMD_CRC)) {
if (host->cmd) {
if (status & CMD_TIMEOUT) {
- OMAP_HSMMC_WRITE(host->base, SYSCTL,
- OMAP_HSMMC_READ(host->base,
- SYSCTL) | SRC);
- while (OMAP_HSMMC_READ(host->base,
- SYSCTL) & SRC)
- ;
-
+ mmc_omap_reset_controller_fsm(host, SRC);
host->cmd->error = -ETIMEDOUT;
} else {
host->cmd->error = -EILSEQ;
}
end_cmd = 1;
}
- if (host->data)
+ if (host->data) {
mmc_dma_cleanup(host);
+ mmc_omap_reset_controller_fsm(host, SRD);
+ }
}
if ((status & DATA_TIMEOUT) ||
(status & DATA_CRC)) {
@@ -426,12 +449,7 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
mmc_dma_cleanup(host);
else
host->data->error = -EILSEQ;
- OMAP_HSMMC_WRITE(host->base, SYSCTL,
- OMAP_HSMMC_READ(host->base,
- SYSCTL) | SRD);
- while (OMAP_HSMMC_READ(host->base,
- SYSCTL) & SRD)
- ;
+ mmc_omap_reset_controller_fsm(host, SRD);
end_trans = 1;
}
}
@@ -456,13 +474,20 @@ 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 +510,26 @@ 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);
@@ -517,16 +549,15 @@ static void mmc_omap_detect(struct work_struct *work)
{
struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
mmc_carddetect_work);
+ struct omap_mmc_slot_data *slot = &mmc_slot(host);
+
+ host->carddetect = slot->card_detect(slot->card_detect_irq);
sysfs_notify(&host->mmc->class_dev.kobj, NULL, "cover_switch");
if (host->carddetect) {
mmc_detect_change(host->mmc, (HZ * 200) / 1000);
} else {
- OMAP_HSMMC_WRITE(host->base, SYSCTL,
- OMAP_HSMMC_READ(host->base, SYSCTL) | SRD);
- while (OMAP_HSMMC_READ(host->base, SYSCTL) & SRD)
- ;
-
+ mmc_omap_reset_controller_fsm(host, SRD);
mmc_detect_change(host->mmc, (HZ * 50) / 1000);
}
}
@@ -538,7 +569,6 @@ static irqreturn_t omap_mmc_cd_handler(int irq, void *dev_id)
{
struct mmc_omap_host *host = (struct mmc_omap_host *)dev_id;
- host->carddetect = mmc_slot(host).card_detect(irq);
schedule_work(&host->mmc_carddetect_work);
return IRQ_HANDLED;
@@ -757,10 +787,14 @@ 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)
@@ -784,7 +818,9 @@ 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)) {
/*
@@ -1137,7 +1173,9 @@ 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);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.