[PATCH] mmc: move regulator handling to core

[daniel@caiaq.de (Daniel Mack)]

At the moment, regulator operations are done from individual mmc host
drivers. This is a problem because the regulators are not claimed
exclusively but the mmc core enables and disables them according to the
return value of regulator_is_enabled(). That can lead to a number of
problems and warnings when regulators are shared among multiple
consumers or if regulators are marked as 'always_on'.

Fix this by moving the some logic to the core, and put the regulator
reference to the mmc_host struct and let it do its own supply state
tracking so that the reference counting in the regulator won't get
confused.

[Note that I could only compile-test the mmci.c change]

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Cliff Brake <cbrake@bec-systems.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: linux-mmc at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
---
 drivers/mmc/core/core.c   |   36 ++++++++++++++++++++----------------
 drivers/mmc/core/host.c   |    3 +++
 drivers/mmc/host/mmci.c   |   28 ++++++++++++----------------
 drivers/mmc/host/mmci.h   |    1 -
 drivers/mmc/host/pxamci.c |   20 ++++++++------------
 include/linux/mmc/host.h  |   10 ++++++----
 6 files changed, 49 insertions(+), 49 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 7dab2e5..9acb655 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -727,13 +727,13 @@ EXPORT_SYMBOL(mmc_vddrange_to_ocrmask);
  * regulator.  This would normally be called before registering the
  * MMC host adapter.
  */
-int mmc_regulator_get_ocrmask(struct regulator *supply)
+int mmc_regulator_get_ocrmask(struct mmc_host *host)
 {
 	int			result = 0;
 	int			count;
 	int			i;
 
-	count = regulator_count_voltages(supply);
+	count = regulator_count_voltages(host->vcc);
 	if (count < 0)
 		return count;
 
@@ -741,7 +741,7 @@ int mmc_regulator_get_ocrmask(struct regulator *supply)
 		int		vdd_uV;
 		int		vdd_mV;
 
-		vdd_uV = regulator_list_voltage(supply, i);
+		vdd_uV = regulator_list_voltage(host->vcc, i);
 		if (vdd_uV <= 0)
 			continue;
 
@@ -755,24 +755,22 @@ EXPORT_SYMBOL(mmc_regulator_get_ocrmask);
 
 /**
  * mmc_regulator_set_ocr - set regulator to match host->ios voltage
+ * @host: the mmc_host
  * @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
- * @supply: regulator to use
  *
  * Returns zero on success, else negative errno.
  *
  * MMC host drivers may use this to enable or disable a regulator using
- * a particular supply voltage.  This would normally be called from the
+ * the registered 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 *host, 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 (!host->vcc || IS_ERR(host->vcc))
+		return -EINVAL;
 
 	if (vdd_bit) {
 		int		tmp;
@@ -795,18 +793,24 @@ int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit)
 		/* avoid needless changes to this voltage; the regulator
 		 * might not allow this operation
 		 */
-		voltage = regulator_get_voltage(supply);
+		voltage = regulator_get_voltage(host->vcc);
 		if (voltage < 0)
 			result = voltage;
 		else if (voltage < min_uV || voltage > max_uV)
-			result = regulator_set_voltage(supply, min_uV, max_uV);
+			result = regulator_set_voltage(host->vcc, min_uV, max_uV);
 		else
 			result = 0;
 
-		if (result == 0 && !enabled)
-			result = regulator_enable(supply);
-	} else if (enabled) {
-		result = regulator_disable(supply);
+		if (result == 0 && !host->vcc_enabled) {
+			result = regulator_enable(host->vcc);
+
+			if (result == 0)
+				host->vcc_enabled = 1;
+		}
+	} else if (host->vcc_enabled) {
+		result = regulator_disable(host->vcc);
+		if (result == 0)
+			host->vcc_enabled = 0;
 	}
 
 	return result;
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index a268d12..f422d1f 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -18,6 +18,7 @@
 #include <linux/leds.h>
 
 #include <linux/mmc/host.h>
+#include <linux/regulator/consumer.h>
 
 #include "core.h"
 #include "host.h"
@@ -154,6 +155,8 @@ void mmc_remove_host(struct mmc_host *host)
 	mmc_remove_host_debugfs(host);
 #endif
 
+	regulator_put(host->vcc);
+
 	device_del(&host->class_dev);
 
 	led_trigger_unregister_simple(host->led);
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 705a589..eea9cde 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -455,15 +455,15 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 	switch (ios->power_mode) {
 	case MMC_POWER_OFF:
-		if(host->vcc &&
-		   regulator_is_enabled(host->vcc))
-			regulator_disable(host->vcc);
+		if(mmc->vcc && mmc->vcc_enabled) {
+			regulator_disable(mmc->vcc);
+			mmc->vcc_enabled = 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);
+		/* This implicitly enables the regulator */
+		mmc_regulator_set_ocr(mmc, ios->vdd);
 #endif
 		/*
 		 * The translate_vdd function is not used if you have
@@ -473,7 +473,7 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		 * a regulator, we might have some other platform specific
 		 * power control behind this translate function.
 		 */
-		if (!host->vcc && host->plat->translate_vdd)
+		if (!mmc->vcc && host->plat->translate_vdd)
 			pwr |= host->plat->translate_vdd(mmc_dev(mmc), ios->vdd);
 		/* The ST version does not have this, fall through to POWER_ON */
 		if (host->hw_designer != AMBA_VENDOR_ST) {
@@ -621,11 +621,11 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
 	mmc->f_max = min(host->mclk, fmax);
 #ifdef CONFIG_REGULATOR
 	/* If we're using the regulator framework, try to fetch a regulator */
-	host->vcc = regulator_get(&dev->dev, "vmmc");
-	if (IS_ERR(host->vcc))
-		host->vcc = NULL;
+	mmc->vcc = regulator_get(&dev->dev, "vmmc");
+	if (IS_ERR(mmc->vcc))
+		mmc->vcc = NULL;
 	else {
-		int mask = mmc_regulator_get_ocrmask(host->vcc);
+		int mask = mmc_regulator_get_ocrmask(mmc);
 
 		if (mask < 0)
 			dev_err(&dev->dev, "error getting OCR mask (%d)\n",
@@ -640,7 +640,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
 	}
 #endif
 	/* Fall back to platform data if no regulator is found */
-	if (host->vcc == NULL)
+	if (mmc->vcc == NULL)
 		mmc->ocr_avail = plat->ocr_mask;
 	mmc->caps = plat->capabilities;
 
@@ -777,10 +777,6 @@ 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);
-		regulator_put(host->vcc);
-
 		mmc_free_host(mmc);
 
 		amba_release_regions(dev);
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 1ceb9a9..a7f9a51 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -175,7 +175,6 @@ struct mmci_host {
 	struct scatterlist	*sg_ptr;
 	unsigned int		sg_off;
 	unsigned int		size;
-	struct regulator	*vcc;
 };
 
 static inline void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
diff --git a/drivers/mmc/host/pxamci.c b/drivers/mmc/host/pxamci.c
index fb0978c..25d2367 100644
--- a/drivers/mmc/host/pxamci.c
+++ b/drivers/mmc/host/pxamci.c
@@ -69,25 +69,23 @@ struct pxamci_host {
 	unsigned int		dma_dir;
 	unsigned int		dma_drcmrrx;
 	unsigned int		dma_drcmrtx;
-
-	struct regulator	*vcc;
 };
 
 static inline void pxamci_init_ocr(struct pxamci_host *host)
 {
 #ifdef CONFIG_REGULATOR
-	host->vcc = regulator_get(mmc_dev(host->mmc), "vmmc");
+	host->mmc->vcc = regulator_get(mmc_dev(host->mmc), "vmmc");
 
-	if (IS_ERR(host->vcc))
-		host->vcc = NULL;
+	if (IS_ERR(host->mmc->vcc))
+		host->mmc->vcc = NULL;
 	else {
-		host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->vcc);
+		host->mmc->ocr_avail = mmc_regulator_get_ocrmask(host->mmc);
 		if (host->pdata && host->pdata->ocr_mask)
 			dev_warn(mmc_dev(host->mmc),
 				"given ocr_mask will not be used\n");
 	}
 #endif
-	if (host->vcc == NULL) {
+	if (host->mmc->vcc == NULL) {
 		/* fall-back to platform data */
 		host->mmc->ocr_avail = host->pdata ?
 			host->pdata->ocr_mask :
@@ -100,10 +98,10 @@ static inline void pxamci_set_power(struct pxamci_host *host, unsigned int vdd)
 	int on;
 
 #ifdef CONFIG_REGULATOR
-	if (host->vcc)
-		mmc_regulator_set_ocr(host->vcc, vdd);
+	if (host->mmc->vcc)
+		mmc_regulator_set_ocr(host->mmc, vdd);
 #endif
-	if (!host->vcc && host->pdata &&
+	if (!host->mmc->vcc && host->pdata &&
 	    gpio_is_valid(host->pdata->gpio_power)) {
 		on = ((1 << vdd) & host->pdata->ocr_mask);
 		gpio_set_value(host->pdata->gpio_power,
@@ -775,8 +773,6 @@ static int pxamci_remove(struct platform_device *pdev)
 			gpio_free(gpio_ro);
 		if (gpio_is_valid(gpio_power))
 			gpio_free(gpio_power);
-		if (host->vcc)
-			regulator_put(host->vcc);
 
 		if (host->pdata && host->pdata->exit)
 			host->pdata->exit(&pdev->dev, mmc);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index eaf3636..2c1b079 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -111,6 +111,7 @@ struct mmc_host_ops {
 
 struct mmc_card;
 struct device;
+struct regulator;
 
 struct mmc_host {
 	struct device		*parent;
@@ -203,6 +204,9 @@ struct mmc_host {
 
 	struct dentry		*debugfs_root;
 
+	struct regulator	*vcc;
+	unsigned int		 vcc_enabled:1;
+
 	unsigned long		private[0] ____cacheline_aligned;
 };
 
@@ -237,10 +241,8 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)
 	wake_up_process(host->sdio_irq_thread);
 }
 
-struct regulator;
-
-int mmc_regulator_get_ocrmask(struct regulator *supply);
-int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit);
+int mmc_regulator_get_ocrmask(struct mmc_host *host);
+int mmc_regulator_set_ocr(struct mmc_host *host, unsigned short vdd_bit);
 
 int mmc_card_awake(struct mmc_host *host);
 int mmc_card_sleep(struct mmc_host *host);
-- 
1.6.5.2