mfd: stmpe: add optional regulators

The STMPE has VCC and VIO supply lines, and sometimes (as on
Ux500) this comes from a software-controlled regulator. Make
it possible to supply the STMPE with power from these
regulators.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/mfd/stmpe.c

@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/mfd/core.h>
 #include <linux/delay.h>
+#include <linux/regulator/consumer.h>
 #include "stmpe.h"
 
 static int __stmpe_enable(struct stmpe *stmpe, unsigned int blocks)
@@ -1186,6 +1187,18 @@ int stmpe_probe(struct stmpe_client_info *ci, int partnum)
 	stmpe->variant = stmpe_variant_info[partnum];
 	stmpe->regs = stmpe->variant->regs;
 	stmpe->num_gpios = stmpe->variant->num_gpios;
+	stmpe->vcc = devm_regulator_get_optional(ci->dev, "vcc");
+	if (!IS_ERR(stmpe->vcc)) {
+		ret = regulator_enable(stmpe->vcc);
+		if (ret)
+			dev_warn(ci->dev, "failed to enable VCC supply\n");
+	}
+	stmpe->vio = devm_regulator_get_optional(ci->dev, "vio");
+	if (!IS_ERR(stmpe->vio)) {
+		ret = regulator_enable(stmpe->vio);
+		if (ret)
+			dev_warn(ci->dev, "failed to enable VIO supply\n");
+	}
 	dev_set_drvdata(stmpe->dev, stmpe);
 
 	if (ci->init)
@@ -1252,6 +1265,11 @@ int stmpe_probe(struct stmpe_client_info *ci, int partnum)
 
 int stmpe_remove(struct stmpe *stmpe)
 {
+	if (!IS_ERR(stmpe->vio))
+		regulator_disable(stmpe->vio);
+	if (!IS_ERR(stmpe->vcc))
+		regulator_disable(stmpe->vcc);
+
 	mfd_remove_devices(stmpe->dev);
 
 	return 0;