mmc: Move regulator handling closer to core

After discovering a problem in regulator reference counting I took Mark
Brown's advice to move the reference count into the MMC core by making the
regulator status a member of struct mmc_host.

I took this opportunity to also implement NULL versions of
the regulator functions so as to rid the driver code from
some ugly #ifdef CONFIG_REGULATOR clauses.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Sundar Iyer <sundar.iyer@stericsson.com>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Cliff Brake <cbrake@bec-systems.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

5 files changed, 101 insertions, 37 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index c5e3c9bf6fdd..46029d5c0364 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -772,8 +772,9 @@ EXPORT_SYMBOL(mmc_regulator_get_ocrmask);
 
 /**
  * mmc_regulator_set_ocr - set regulator to match host->ios voltage
- * @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
+ * @mmc: the host to regulate
  * @supply: regulator to use
+ * @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
  *
  * Returns zero on success, else negative errno.
  *
@@ -781,15 +782,12 @@ EXPORT_SYMBOL(mmc_regulator_get_ocrmask);
  * a particular supply voltage.  This would normally be called from the
  * set_ios() method.
  */
-int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit)
+int mmc_regulator_set_ocr(struct mmc_host *mmc,
+                        struct regulator *supply,
+                        unsigned short vdd_bit)
 {
         int                     result = 0;
         int                     min_uV, max_uV;
-        int                     enabled;
-
-        enabled = regulator_is_enabled(supply);
-        if (enabled < 0)
-                return enabled;
 
         if (vdd_bit) {
                 int             tmp;
@@ -820,17 +818,25 @@ int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit)
                 else
                         result = 0;
 
-                if (result == 0 && !enabled)
+                if (result == 0 && !mmc->regulator_enabled) {
                         result = regulator_enable(supply);
-        } else if (enabled) {
+                        if (!result)
+                                mmc->regulator_enabled = true;
+                }
+        } else if (mmc->regulator_enabled) {
                 result = regulator_disable(supply);
+                if (result == 0)
+                        mmc->regulator_enabled = false;
         }
 
+        if (result)
+                dev_err(mmc_dev(mmc),
+                        "could not set regulator OCR (%d)\n", result);
         return result;
 }
 EXPORT_SYMBOL(mmc_regulator_set_ocr);
 
-#endif
+#endif /* CONFIG_REGULATOR */
 
 /*
  * Mask off any voltages we don't support and select
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 5f2e72d38b5d..87b4fc6c98c2 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -523,19 +523,27 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
         struct mmci_host *host = mmc_priv(mmc);
         u32 pwr = 0;
         unsigned long flags;
+        int ret;
 
         switch (ios->power_mode) {
         case MMC_POWER_OFF:
-                if(host->vcc &&
-                   regulator_is_enabled(host->vcc))
-                        regulator_disable(host->vcc);
+                if (host->vcc)
+                        ret = mmc_regulator_set_ocr(mmc, host->vcc, 0);
                 break;
         case MMC_POWER_UP:
-#ifdef CONFIG_REGULATOR
-                if (host->vcc)
-                        /* This implicitly enables the regulator */
-                        mmc_regulator_set_ocr(host->vcc, ios->vdd);
-#endif
+                if (host->vcc) {
+                        ret = mmc_regulator_set_ocr(mmc, host->vcc, ios->vdd);
+                        if (ret) {
+                                dev_err(mmc_dev(mmc), "unable to set OCR\n");
+                                /*
+                                 * The .set_ios() function in the mmc_host_ops
+                                 * struct return void, and failing to set the
+                                 * power should be rare so we print an error
+                                 * and return here.
+                                 */
+                                return;
+                        }
+                }
                 if (host->plat->vdd_handler)
                         pwr |= host->plat->vdd_handler(mmc_dev(mmc), ios->vdd,
                                                        ios->power_mode);
@@ -869,8 +877,8 @@ static int __devexit mmci_remove(struct amba_device *dev)
                 clk_disable(host->clk);
                 clk_put(host->clk);
 
-                if (regulator_is_enabled(host->vcc))
-                        regulator_disable(host->vcc);
+                if (host->vcc)
+                        mmc_regulator_set_ocr(mmc, host->vcc, 0);
                 regulator_put(host->vcc);
 
                 mmc_free_host(mmc);
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 03c26e026506..8c863ccb1bfe 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -250,9 +250,9 @@ static int omap_hsmmc_1_set_power(struct device *dev, int slot, int power_on,
                 mmc_slot(host).before_set_reg(dev, slot, power_on, vdd);
 
         if (power_on)
-                ret = mmc_regulator_set_ocr(host->vcc, vdd);
+                ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
         else
-                ret = mmc_regulator_set_ocr(host->vcc, 0);
+                ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
 
         if (mmc_slot(host).after_set_reg)
                 mmc_slot(host).after_set_reg(dev, slot, power_on, vdd);
@@ -291,18 +291,23 @@ static int omap_hsmmc_23_set_power(struct device *dev, int slot, int power_on,
          * chips/cards need an interface voltage rail too.
          */
         if (power_on) {
-                ret = mmc_regulator_set_ocr(host->vcc, vdd);
+                ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
                 /* Enable interface voltage rail, if needed */
                 if (ret == 0 && host->vcc_aux) {
                         ret = regulator_enable(host->vcc_aux);
                         if (ret < 0)
-                                ret = mmc_regulator_set_ocr(host->vcc, 0);
+                                ret = mmc_regulator_set_ocr(host->mmc,
+                                                        host->vcc, 0);
                 }
         } else {
+                /* Shut down the rail */
                 if (host->vcc_aux)
                         ret = regulator_disable(host->vcc_aux);
-                if (ret == 0)
-                        ret = mmc_regulator_set_ocr(host->vcc, 0);
+                if (!ret) {
+                        /* Then proceed to shut down the local regulator */
+                        ret = mmc_regulator_set_ocr(host->mmc,
+                                                host->vcc, 0);
+                }
         }
 
         if (mmc_slot(host).after_set_reg)
@@ -343,9 +348,9 @@ static int omap_hsmmc_23_set_sleep(struct device *dev, int slot, int sleep,
         if (cardsleep) {
                 /* VCC can be turned off if card is asleep */
                 if (sleep)
-                        err = mmc_regulator_set_ocr(host->vcc, 0);
+                        err = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
                 else
-                        err = mmc_regulator_set_ocr(host->vcc, vdd);
+                        err = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
         } else
                 err = regulator_set_mode(host->vcc, mode);
         if (err)
diff --git a/drivers/mmc/host/pxamci.c b/drivers/mmc/host/pxamci.c
index b7dfcac31e8a..7257738fd7da 100644
--- a/drivers/mmc/host/pxamci.c
+++ b/drivers/mmc/host/pxamci.c
@@ -99,14 +99,25 @@ static inline void pxamci_init_ocr(struct pxamci_host *host)
         }
 }
 
-static inline void pxamci_set_power(struct pxamci_host *host, unsigned int vdd)
+static inline int pxamci_set_power(struct pxamci_host *host,
+                                    unsigned char power_mode,
+                                    unsigned int vdd)
 {
         int on;
 
-#ifdef CONFIG_REGULATOR
-        if (host->vcc)
-                mmc_regulator_set_ocr(host->vcc, vdd);
-#endif
+        if (host->vcc) {
+                int ret;
+
+                if (power_mode == MMC_POWER_UP) {
+                        ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
+                        if (ret)
+                                return ret;
+                } else if (power_mode == MMC_POWER_OFF) {
+                        ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
+                        if (ret)
+                                return ret;
+                }
+        }
         if (!host->vcc && host->pdata &&
             gpio_is_valid(host->pdata->gpio_power)) {
                 on = ((1 << vdd) & host->pdata->ocr_mask);
@@ -115,6 +126,8 @@ static inline void pxamci_set_power(struct pxamci_host *host, unsigned int vdd)
         }
         if (!host->vcc && host->pdata && host->pdata->setpower)
                 host->pdata->setpower(mmc_dev(host->mmc), vdd);
+
+        return 0;
 }
 
 static void pxamci_stop_clock(struct pxamci_host *host)
@@ -490,9 +503,21 @@ static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
         }
 
         if (host->power_mode != ios->power_mode) {
+                int ret;
+
                 host->power_mode = ios->power_mode;
 
-                pxamci_set_power(host, ios->vdd);
+                ret = pxamci_set_power(host, ios->power_mode, ios->vdd);
+                if (ret) {
+                        dev_err(mmc_dev(mmc), "unable to set power\n");
+                        /*
+                         * The .set_ios() function in the mmc_host_ops
+                         * struct return void, and failing to set the
+                         * power should be rare so we print an error and
+                         * return here.
+                         */
+                        return;
+                }
 
                 if (ios->power_mode == MMC_POWER_ON)
                         host->cmdat |= CMDAT_INIT;
@@ -503,8 +528,8 @@ static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
         else
                 host->cmdat &= ~CMDAT_SD_4DAT;
 
-        pr_debug("PXAMCI: clkrt = %x cmdat = %x\n",
-                 host->clkrt, host->cmdat);
+        dev_dbg(mmc_dev(mmc), "PXAMCI: clkrt = %x cmdat = %x\n",
+                host->clkrt, host->cmdat);
 }
 
 static void pxamci_enable_sdio_irq(struct mmc_host *host, int enable)
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 20be040649a9..ccac56ae1286 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -212,6 +212,10 @@ struct mmc_host {
         struct led_trigger      *led;           /* activity led */
 #endif
 
+#ifdef CONFIG_REGULATOR
+        bool                    regulator_enabled; /* regulator state */
+#endif
+
         struct dentry           *debugfs_root;
 
         unsigned long           private[0] ____cacheline_aligned;
@@ -250,8 +254,24 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)
 
 struct regulator;
 
+#ifdef CONFIG_REGULATOR
 int mmc_regulator_get_ocrmask(struct regulator *supply);
-int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit);
+int mmc_regulator_set_ocr(struct mmc_host *mmc,
+                        struct regulator *supply,
+                        unsigned short vdd_bit);
+#else
+static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
+{
+        return 0;
+}
+
+static inline int mmc_regulator_set_ocr(struct mmc_host *mmc,
+                                 struct regulator *supply,
+                                 unsigned short vdd_bit)
+{
+        return 0;
+}
+#endif
 
 int mmc_card_awake(struct mmc_host *host);
 int mmc_card_sleep(struct mmc_host *host);