mmc: add a function to get regulators, supplying card's power

Add a function to get regulators, supplying card's Vdd and Vccq on a
specific host. If a Vdd supplying regulator is found, the function checks,
whether a valid OCR mask can be obtained from it. The Vccq regulator is
optional. A failure to get it is not fatal.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/core.c

@@ -1022,6 +1022,29 @@ int mmc_regulator_set_ocr(struct mmc_host *mmc,
 }
 EXPORT_SYMBOL_GPL(mmc_regulator_set_ocr);
 
+int mmc_regulator_get_supply(struct mmc_host *mmc)
+{
+	struct device *dev = mmc_dev(mmc);
+	struct regulator *supply;
+	int ret;
+
+	supply = devm_regulator_get(dev, "vmmc");
+	mmc->supply.vmmc = supply;
+	mmc->supply.vqmmc = devm_regulator_get(dev, "vqmmc");
+
+	if (IS_ERR(supply))
+		return PTR_ERR(supply);
+
+	ret = mmc_regulator_get_ocrmask(supply);
+	if (ret > 0)
+		mmc->ocr_avail = ret;
+	else
+		dev_warn(mmc_dev(mmc), "Failed getting OCR mask: %d\n", ret);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mmc_regulator_get_supply);
+
 #endif /* CONFIG_REGULATOR */
 
 /*

include/linux/mmc/host.h

@@ -155,6 +155,13 @@ struct mmc_hotplug {
 	void *handler_priv;
 };
 
+struct regulator;
+
+struct mmc_supply {
+	struct regulator *vmmc;		/* Card power supply */
+	struct regulator *vqmmc;	/* Optional Vccq supply */
+};
+
 struct mmc_host {
 	struct device		*parent;
 	struct device		class_dev;
@@ -309,6 +316,7 @@ struct mmc_host {
 #ifdef CONFIG_REGULATOR
 	bool			regulator_enabled; /* regulator state */
 #endif
+	struct mmc_supply	supply;
 
 	struct dentry		*debugfs_root;
 
@@ -357,13 +365,12 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)
 	wake_up_process(host->sdio_irq_thread);
 }
 
-struct regulator;
-
 #ifdef CONFIG_REGULATOR
 int mmc_regulator_get_ocrmask(struct regulator *supply);
 int mmc_regulator_set_ocr(struct mmc_host *mmc,
 			struct regulator *supply,
 			unsigned short vdd_bit);
+int mmc_regulator_get_supply(struct mmc_host *mmc);
 #else
 static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
 {
@@ -376,6 +383,11 @@ static inline int mmc_regulator_set_ocr(struct mmc_host *mmc,
 {
 	return 0;
 }
+
+static inline int mmc_regulator_get_supply(struct mmc_host *mmc)
+{
+	return 0;
+}
 #endif
 
 int mmc_card_awake(struct mmc_host *host);