From: Balaji T K <balaj...@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 <balaj...@ti.com>
Signed-off-by: Sourav Poddar <sourav.pod...@ti.com>
[kis...@ti.com : cleanup the voltage switch sequence]
Signed-off-by: Kishon Vijay Abraham I <kis...@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

--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to