omap_hsmmc: context save/restore support

Keep the context over PM dynamic OFF states.

Signed-off-by: Denis Karpov <ext-denis.2.karpov@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 184 insertions, 10 deletions

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 30b863b2c510..74d506a6ffec 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -37,6 +37,7 @@
 
 /* OMAP HSMMC Host Controller Registers */
 #define OMAP_HSMMC_SYSCONFIG    0x0010
+#define OMAP_HSMMC_SYSSTATUS    0x0014
 #define OMAP_HSMMC_CON          0x002C
 #define OMAP_HSMMC_BLK          0x0104
 #define OMAP_HSMMC_ARG          0x0108
@@ -96,6 +97,8 @@
 #define DUAL_VOLT_OCR_BIT       7
 #define SRC                     (1 << 25)
 #define SRD                     (1 << 26)
+#define SOFTRESET               (1 << 1)
+#define RESETDONE               (1 << 0)
 
 /*
  * FIXME: Most likely all the data using these _DEVID defines should come
@@ -154,6 +157,8 @@ struct mmc_omap_host {
         int                     slot_id;
         int                     dbclk_enabled;
         int                     response_busy;
+        int                     context_loss;
+
         struct  omap_mmc_platform_data  *pdata;
 };
 
@@ -168,6 +173,166 @@ static void omap_mmc_stop_clock(struct mmc_omap_host *host)
                 dev_dbg(mmc_dev(host->mmc), "MMC Clock is not stoped\n");
 }
 
+#ifdef CONFIG_PM
+
+/*
+ * Restore the MMC host context, if it was lost as result of a
+ * power state change.
+ */
+static int omap_mmc_restore_ctx(struct mmc_omap_host *host)
+{
+        struct mmc_ios *ios = &host->mmc->ios;
+        struct omap_mmc_platform_data *pdata = host->pdata;
+        int context_loss = 0;
+        u32 hctl, capa, con;
+        u16 dsor = 0;
+        unsigned long timeout;
+
+        if (pdata->get_context_loss_count) {
+                context_loss = pdata->get_context_loss_count(host->dev);
+                if (context_loss < 0)
+                        return 1;
+        }
+
+        dev_dbg(mmc_dev(host->mmc), "context was %slost\n",
+                context_loss == host->context_loss ? "not " : "");
+        if (host->context_loss == context_loss)
+                return 1;
+
+        /* Wait for hardware reset */
+        timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
+        while ((OMAP_HSMMC_READ(host->base, SYSSTATUS) & RESETDONE) != RESETDONE
+                && time_before(jiffies, timeout))
+                ;
+
+        /* Do software reset */
+        OMAP_HSMMC_WRITE(host->base, SYSCONFIG, SOFTRESET);
+        timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
+        while ((OMAP_HSMMC_READ(host->base, SYSSTATUS) & RESETDONE) != RESETDONE
+                && time_before(jiffies, timeout))
+                ;
+
+        OMAP_HSMMC_WRITE(host->base, SYSCONFIG,
+                        OMAP_HSMMC_READ(host->base, SYSCONFIG) | AUTOIDLE);
+
+        if (host->id == OMAP_MMC1_DEVID) {
+                if (host->power_mode != MMC_POWER_OFF &&
+                    (1 << ios->vdd) <= MMC_VDD_23_24)
+                        hctl = SDVS18;
+                else
+                        hctl = SDVS30;
+                capa = VS30 | VS18;
+        } else {
+                hctl = SDVS18;
+                capa = VS18;
+        }
+
+        OMAP_HSMMC_WRITE(host->base, HCTL,
+                        OMAP_HSMMC_READ(host->base, HCTL) | hctl);
+
+        OMAP_HSMMC_WRITE(host->base, CAPA,
+                        OMAP_HSMMC_READ(host->base, CAPA) | capa);
+
+        OMAP_HSMMC_WRITE(host->base, HCTL,
+                        OMAP_HSMMC_READ(host->base, HCTL) | SDBP);
+
+        timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
+        while ((OMAP_HSMMC_READ(host->base, HCTL) & SDBP) != SDBP
+                && time_before(jiffies, timeout))
+                ;
+
+        OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
+        OMAP_HSMMC_WRITE(host->base, ISE, INT_EN_MASK);
+        OMAP_HSMMC_WRITE(host->base, IE, INT_EN_MASK);
+
+        /* Do not initialize card-specific things if the power is off */
+        if (host->power_mode == MMC_POWER_OFF)
+                goto out;
+
+        con = OMAP_HSMMC_READ(host->base, CON);
+        switch (ios->bus_width) {
+        case MMC_BUS_WIDTH_8:
+                OMAP_HSMMC_WRITE(host->base, CON, con | DW8);
+                break;
+        case MMC_BUS_WIDTH_4:
+                OMAP_HSMMC_WRITE(host->base, CON, con & ~DW8);
+                OMAP_HSMMC_WRITE(host->base, HCTL,
+                        OMAP_HSMMC_READ(host->base, HCTL) | FOUR_BIT);
+                break;
+        case MMC_BUS_WIDTH_1:
+                OMAP_HSMMC_WRITE(host->base, CON, con & ~DW8);
+                OMAP_HSMMC_WRITE(host->base, HCTL,
+                        OMAP_HSMMC_READ(host->base, HCTL) & ~FOUR_BIT);
+                break;
+        }
+
+        if (ios->clock) {
+                dsor = OMAP_MMC_MASTER_CLOCK / ios->clock;
+                if (dsor < 1)
+                        dsor = 1;
+
+                if (OMAP_MMC_MASTER_CLOCK / dsor > ios->clock)
+                        dsor++;
+
+                if (dsor > 250)
+                        dsor = 250;
+        }
+
+        OMAP_HSMMC_WRITE(host->base, SYSCTL,
+                OMAP_HSMMC_READ(host->base, SYSCTL) & ~CEN);
+        OMAP_HSMMC_WRITE(host->base, SYSCTL, (dsor << 6) | (DTO << 16));
+        OMAP_HSMMC_WRITE(host->base, SYSCTL,
+                OMAP_HSMMC_READ(host->base, SYSCTL) | ICE);
+
+        timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
+        while ((OMAP_HSMMC_READ(host->base, SYSCTL) & ICS) != ICS
+                && time_before(jiffies, timeout))
+                ;
+
+        OMAP_HSMMC_WRITE(host->base, SYSCTL,
+                OMAP_HSMMC_READ(host->base, SYSCTL) | CEN);
+
+        con = OMAP_HSMMC_READ(host->base, CON);
+        if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
+                OMAP_HSMMC_WRITE(host->base, CON, con | OD);
+        else
+                OMAP_HSMMC_WRITE(host->base, CON, con & ~OD);
+out:
+        host->context_loss = context_loss;
+
+        dev_dbg(mmc_dev(host->mmc), "context is restored\n");
+        return 0;
+}
+
+/*
+ * Save the MMC host context (store the number of power state changes so far).
+ */
+static void omap_mmc_save_ctx(struct mmc_omap_host *host)
+{
+        struct omap_mmc_platform_data *pdata = host->pdata;
+        int context_loss;
+
+        if (pdata->get_context_loss_count) {
+                context_loss = pdata->get_context_loss_count(host->dev);
+                if (context_loss < 0)
+                        return;
+                host->context_loss = context_loss;
+        }
+}
+
+#else
+
+static int omap_mmc_restore_ctx(struct mmc_omap_host *host)
+{
+        return 0;
+}
+
+static void omap_mmc_save_ctx(struct mmc_omap_host *host)
+{
+}
+
+#endif
+
 /*
  * Send init stream sequence to card
  * before sending IDLE command
@@ -830,6 +995,7 @@ static int omap_mmc_enable(struct mmc_host *mmc)
         if (err)
                 return err;
         dev_dbg(mmc_dev(host->mmc), "mmc_fclk: enabled\n");
+        omap_mmc_restore_ctx(host);
         return 0;
 }
 
@@ -837,6 +1003,7 @@ static int omap_mmc_disable(struct mmc_host *mmc, int lazy)
 {
         struct mmc_omap_host *host = mmc_priv(mmc);
 
+        omap_mmc_save_ctx(host);
         clk_disable(host->fclk);
         dev_dbg(mmc_dev(host->mmc), "mmc_fclk: disabled\n");
         return 0;
@@ -941,7 +1108,7 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
         /* Wait till the ICS bit is set */
         timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
-        while ((OMAP_HSMMC_READ(host->base, SYSCTL) & ICS) != 0x2
+        while ((OMAP_HSMMC_READ(host->base, SYSCTL) & ICS) != ICS
                 && time_before(jiffies, timeout))
                 msleep(1);
 
@@ -1021,12 +1188,19 @@ static int mmc_regs_show(struct seq_file *s, void *data)
 {
         struct mmc_host *mmc = s->private;
         struct mmc_omap_host *host = mmc_priv(mmc);
+        struct omap_mmc_platform_data *pdata = host->pdata;
+        int context_loss = 0;
+
+        if (pdata->get_context_loss_count)
+                context_loss = pdata->get_context_loss_count(host->dev);
 
         seq_printf(s, "mmc%d:\n"
                         " enabled:\t%d\n"
                         " nesting_cnt:\t%d\n"
+                        " ctx_loss:\t%d:%d\n"
                         "\nregs:\n",
-                        mmc->index, mmc->enabled ? 1 : 0, mmc->nesting_cnt);
+                        mmc->index, mmc->enabled ? 1 : 0, mmc->nesting_cnt,
+                        host->context_loss, context_loss);
 
         if (clk_enable(host->fclk) != 0) {
                 seq_printf(s, "can't read the regs\n");
@@ -1151,6 +1325,8 @@ static int __init omap_mmc_probe(struct platform_device *pdev)
                 goto err1;
         }
 
+        omap_mmc_save_ctx(host);
+
         mmc->caps |= MMC_CAP_DISABLE;
         mmc_set_disable_delay(mmc, 100);
         if (mmc_host_enable(host->mmc) != 0) {
@@ -1385,21 +1561,19 @@ static int omap_mmc_resume(struct platform_device *pdev)
                 return 0;
 
         if (host) {
-
-                if (mmc_host_enable(host->mmc) != 0)
-                        goto clk_en_err;
-
                 ret = clk_enable(host->iclk);
-                if (ret) {
-                        mmc_host_disable(host->mmc);
-                        clk_put(host->fclk);
+                if (ret)
                         goto clk_en_err;
-                }
 
                 if (clk_enable(host->dbclk) != 0)
                         dev_dbg(mmc_dev(host->mmc),
                                         "Enabling debounce clk failed\n");
 
+                if (mmc_host_enable(host->mmc) != 0) {
+                        clk_disable(host->iclk);
+                        goto clk_en_err;
+                }
+
                 omap_hsmmc_init(host);
 
                 if (host->pdata->resume) {