[PATCH 04/11] mmc: host: omap_hsmmc: add voltage switch support for UHS SD card

Kishon Vijay Abraham I
2015-07-30T07:49:48Z

From: Balaji T K <balajitk@ti.com>

UHS sd card i/o data line can operate at 3V and 1.8V on UHS speed
modes. Add support for signal voltage switch and check for card_busy.

Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
[kishon@ti.com : cleanup the voltage switch sequence]
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/mmc/host/omap_hsmmc.c | 129 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 129 insertions(+)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 306e5c0..e960b5c 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -112,6 +112,9 @@
/* PSTATE */
#define DLEV_DAT(x) (1 << (20 + (x)))

+/* AC12 */
+#define AC12_V1V8_SIGEN (1 << 19)
+
/* Interrupt masks for IE and ISE register */
#define CC_EN (1 << 0)
#define TC_EN (1 << 1)
@@ -151,6 +154,12 @@
#define VDD_1V8 1800000 /* 180000 uV */
#define VDD_3V0 3000000 /* 300000 uV */
#define VDD_165_195 (ffs(MMC_VDD_165_195) - 1)
+#define VDD_30_31 (ffs(MMC_VDD_30_31) - 1)
+
+#define CON_CLKEXTFREE (1 << 16)
+#define CON_PADEN (1 << 15)
+#define PSTATE_CLEV (1 << 24)
+#define PSTATE_DLEV (0xF << 20)

/*
* One controller can have multiple slots, like on some omap boards using
@@ -1851,6 +1860,124 @@ static int omap_hsmmc_multi_io_quirk(struct mmc_card *card,
return blk_size;
}

+static int omap_hsmmc_start_signal_voltage_switch(struct mmc_host *mmc,
+ struct mmc_ios *ios)
+{
+ struct omap_hsmmc_host *host;
+ u32 val = 0;
+ int ret = 0;
+
+ host = mmc_priv(mmc);
+
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
+ val = OMAP_HSMMC_READ(host->base, CAPA);
+ if (!(val & VS30))
+ return -EOPNOTSUPP;
+
+ omap_hsmmc_conf_bus_power(host, ios->signal_voltage);
+
+ val = OMAP_HSMMC_READ(host->base, AC12);
+ val &= ~AC12_V1V8_SIGEN;
+ OMAP_HSMMC_WRITE(host->base, AC12, val);
+
+ ret = mmc_pdata(host)->set_power(host->dev, 1, VDD_30_31);
+ if (ret) {
+ dev_dbg(mmc_dev(host->mmc), "failed to switch to 3v\n");
+ return ret;
+ }
+
+ dev_dbg(mmc_dev(host->mmc), " i/o voltage switch to 3V\n");
+ } else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
+ val = OMAP_HSMMC_READ(host->base, CAPA);
+ if (!(val & VS18))
+ return -EOPNOTSUPP;
+
+ omap_hsmmc_conf_bus_power(host, ios->signal_voltage);
+
+ val = OMAP_HSMMC_READ(host->base, AC12);
+ val |= AC12_V1V8_SIGEN;
+ OMAP_HSMMC_WRITE(host->base, AC12, val);
+
+ ret = mmc_pdata(host)->set_power(host->dev, 1, VDD_165_195);
+ if (ret < 0) {
+ dev_dbg(mmc_dev(host->mmc), "failed to switch 1.8v\n");
+ return ret;
+ }
+ } else {
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int omap_hsmmc_card_busy_low(struct omap_hsmmc_host *host)
+{
+ u32 val;
+ unsigned long timeout;
+
+ val = OMAP_HSMMC_READ(host->base, CON);
+ val &= ~CON_CLKEXTFREE;
+ val |= CON_PADEN;
+ OMAP_HSMMC_WRITE(host->base, CON, val);
+
+ timeout = jiffies + msecs_to_jiffies(1);
+ do {
+ val = OMAP_HSMMC_READ(host->base, PSTATE);
+ if (!(val & (PSTATE_CLEV | PSTATE_DLEV)))
+ return true;
+
+ usleep_range(100, 200);
+ } while (!time_after(jiffies, timeout));
+
+ dev_err(mmc_dev(host->mmc), "timeout : i/o low 0x%x\n", val);
+
+ return false;
+}
+
+static int omap_hsmmc_card_busy_high(struct omap_hsmmc_host *host)
+{
+ u32 val;
+ unsigned long timeout;
+
+ val = OMAP_HSMMC_READ(host->base, CON);
+ val |= CLKEXTFREE;
+ OMAP_HSMMC_WRITE(host->base, CON, val);
+
+ timeout = jiffies + msecs_to_jiffies(1);
+ do {
+ val = OMAP_HSMMC_READ(host->base, PSTATE);
+ if ((val & PSTATE_CLEV) && (val & PSTATE_DLEV)) {
+ val = OMAP_HSMMC_READ(host->base, CON);
+ val &= ~(CON_CLKEXTFREE | CON_PADEN);
+ OMAP_HSMMC_WRITE(host->base, CON, val);
+ return false;
+ }
+
+ usleep_range(100, 200);
+ } while (!time_after(jiffies, timeout));
+
+ dev_err(mmc_dev(host->mmc), "timeout : i/o high 0x%x\n", val);
+
+ return true;
+}
+
+static int omap_hsmmc_card_busy(struct mmc_host *mmc)
+{
+ struct omap_hsmmc_host *host;
+ u32 val;
+ int ret;
+
+ host = mmc_priv(mmc);
+
+ val = OMAP_HSMMC_READ(host->base, AC12);
+ if (val & AC12_V1V8_SIGEN)
+ ret = omap_hsmmc_card_busy_high(host);
+ else
+ ret = omap_hsmmc_card_busy_low(host);
+
+ return ret;
+}
+
static struct mmc_host_ops omap_hsmmc_ops = {
.post_req = omap_hsmmc_post_req,
.pre_req = omap_hsmmc_pre_req,
@@ -1860,6 +1987,8 @@ static struct mmc_host_ops omap_hsmmc_ops = {
.get_ro = mmc_gpio_get_ro,
.init_card = omap_hsmmc_init_card,
.enable_sdio_irq = omap_hsmmc_enable_sdio_irq,
+ .start_signal_voltage_switch = omap_hsmmc_start_signal_voltage_switch,
+ .card_busy = omap_hsmmc_card_busy,
};

#ifdef CONFIG_DEBUG_FS
--
1.7.9.5