From 36e9615bd70dc8cd5d7d4831943f788f5231350f Mon Sep 17 00:00:00 2001
From: Dudley Du <dudl@cypress.com>
Date: Thu, 30 Jul 2015 11:19:18 -0700
Subject: [PATCH] Input: cyapa - add regulator vcc support

We need to power up the chip before we can initialize it.

On systems that delegate task of powering up regulators to firmware we
assume that we'll be simply given a dummy regulator.

Signed-off-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/mouse/cyapa.c | 29 +++++++++++++++++++++++++++++
 drivers/input/mouse/cyapa.h |  1 +
 2 files changed, 30 insertions(+)

diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
index 6195ccb3cfde..1479ca996647 100644
--- a/drivers/input/mouse/cyapa.c
+++ b/drivers/input/mouse/cyapa.c
@@ -21,6 +21,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <linux/pm_runtime.h>
@@ -1241,6 +1242,13 @@ static void cyapa_remove_sysfs_group(void *data)
 	sysfs_remove_group(&cyapa->client->dev.kobj, &cyapa_sysfs_group);
 }
 
+static void cyapa_disable_regulator(void *data)
+{
+	struct cyapa *cyapa = data;
+
+	regulator_disable(cyapa->vcc);
+}
+
 static int cyapa_probe(struct i2c_client *client,
 		       const struct i2c_device_id *dev_id)
 {
@@ -1274,6 +1282,27 @@ static int cyapa_probe(struct i2c_client *client,
 	sprintf(cyapa->phys, "i2c-%d-%04x/input0", client->adapter->nr,
 		client->addr);
 
+	cyapa->vcc = devm_regulator_get(dev, "vcc");
+	if (IS_ERR(cyapa->vcc)) {
+		error = PTR_ERR(cyapa->vcc);
+		dev_err(dev, "failed to get vcc regulator: %d\n", error);
+		return error;
+	}
+
+	error = regulator_enable(cyapa->vcc);
+	if (error) {
+		dev_err(dev, "failed to enable regulator: %d\n", error);
+		return error;
+	}
+
+	error = devm_add_action(dev, cyapa_disable_regulator, cyapa);
+	if (error) {
+		cyapa_disable_regulator(cyapa);
+		dev_err(dev, "failed to add disable regulator action: %d\n",
+			error);
+		return error;
+	}
+
 	error = cyapa_initialize(cyapa);
 	if (error) {
 		dev_err(dev, "failed to detect and initialize tp device.\n");
diff --git a/drivers/input/mouse/cyapa.h b/drivers/input/mouse/cyapa.h
index af1253640590..b812bba8cdd7 100644
--- a/drivers/input/mouse/cyapa.h
+++ b/drivers/input/mouse/cyapa.h
@@ -321,6 +321,7 @@ struct cyapa {
 	u8 status[BL_STATUS_SIZE];
 	bool operational; /* true: ready for data reporting; false: not. */
 
+	struct regulator *vcc;
 	struct i2c_client *client;
 	struct input_dev *input;
 	char phys[32];	/* Device physical location */