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>
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 20be040..ccac56a 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -212,6 +212,10 @@
 	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 @@
 
 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);