commit f9deb41f91c41d9d91a24c84a555ec7fe82620da
author Samu Onkalo <samu.p.onkalo@nokia.com> Fri Oct 22 07:57:24 2010 -0400
committer Guenter Roeck <guenter.roeck@ericsson.com> Mon Oct 25 14:11:38 2010 -0700
tree c301a8324c3bbc779b752cdf47236575a87a26d2
parent 2a346996626ecbb4269c239e9ff7372a182907e9

hwmon: lis3: regulator control

Based on pm_runtime control, turn lis3 regulators on and off.
Perform context save and restore on transitions.

Feature is optional and must be enabled in platform data.

Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

drivers/hwmon/lis3lv02d_i2c.c

diff --git a/drivers/hwmon/lis3lv02d_i2c.c b/drivers/hwmon/lis3lv02d_i2c.c
index d520956..ec35c87 100644
--- a/drivers/hwmon/lis3lv02d_i2c.c
+++ b/drivers/hwmon/lis3lv02d_i2c.c
@@ -30,10 +30,29 @@
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/pm_runtime.h>
+#include <linux/delay.h>
 #include "lis3lv02d.h"
 
 #define DRV_NAME 	"lis3lv02d_i2c"
 
+static const char reg_vdd[]    = "Vdd";
+static const char reg_vdd_io[] = "Vdd_IO";
+
+static int lis3_reg_ctrl(struct lis3lv02d *lis3, bool state)
+{
+	int ret;
+	if (state == LIS3_REG_OFF) {
+		ret = regulator_bulk_disable(ARRAY_SIZE(lis3->regulators),
+					lis3->regulators);
+	} else {
+		ret = regulator_bulk_enable(ARRAY_SIZE(lis3->regulators),
+					lis3->regulators);
+		/* Chip needs time to wakeup. Not mentioned in datasheet */
+		usleep_range(10000, 20000);
+	}
+	return ret;
+}
+
 static inline s32 lis3_i2c_write(struct lis3lv02d *lis3, int reg, u8 value)
 {
 	struct i2c_client *c = lis3->bus_priv;
@@ -52,6 +71,13 @@
 	u8 reg;
 	int ret;
 
+	if (lis3->reg_ctrl)
+		lis3_reg_ctrl(lis3, LIS3_REG_ON);
+
+	lis3->read(lis3, WHO_AM_I, &reg);
+	if (reg != lis3->whoami)
+		printk(KERN_ERR "lis3: power on failure\n");
+
 	/* power up the device */
 	ret = lis3->read(lis3, CTRL_REG1, &reg);
 	if (ret < 0)
@@ -72,6 +98,10 @@
 	struct lis3lv02d_platform_data *pdata = client->dev.platform_data;
 
 	if (pdata) {
+		/* Regulator control is optional */
+		if (pdata->driver_features & LIS3_USE_REGULATOR_CTRL)
+			lis3_dev.reg_ctrl = lis3_reg_ctrl;
+
 		if (pdata->axis_x)
 			lis3lv02d_axis_map.x = pdata->axis_x;
 
@@ -88,6 +118,16 @@
 			goto fail;
 	}
 
+	if (lis3_dev.reg_ctrl) {
+		lis3_dev.regulators[0].supply = reg_vdd;
+		lis3_dev.regulators[1].supply = reg_vdd_io;
+		ret = regulator_bulk_get(&client->dev,
+					ARRAY_SIZE(lis3_dev.regulators),
+					lis3_dev.regulators);
+		if (ret < 0)
+			goto fail;
+	}
+
 	lis3_dev.pdata	  = pdata;
 	lis3_dev.bus_priv = client;
 	lis3_dev.init	  = lis3_i2c_init;
@@ -98,21 +138,34 @@
 	lis3_dev.pm_dev	  = &client->dev;
 
 	i2c_set_clientdata(client, &lis3_dev);
+
+	/* Provide power over the init call */
+	if (lis3_dev.reg_ctrl)
+		lis3_reg_ctrl(&lis3_dev, LIS3_REG_ON);
+
 	ret = lis3lv02d_init_device(&lis3_dev);
+
+	if (lis3_dev.reg_ctrl)
+		lis3_reg_ctrl(&lis3_dev, LIS3_REG_OFF);
 fail:
 	return ret;
 }
 
 static int __devexit lis3lv02d_i2c_remove(struct i2c_client *client)
 {
+	struct lis3lv02d *lis3 = i2c_get_clientdata(client);
 	struct lis3lv02d_platform_data *pdata = client->dev.platform_data;
 
 	if (pdata && pdata->release_resources)
 		pdata->release_resources();
 
 	lis3lv02d_joystick_disable();
+	lis3lv02d_remove_fs(&lis3_dev);
 
-	return lis3lv02d_remove_fs(&lis3_dev);
+	if (lis3_dev.reg_ctrl)
+		regulator_bulk_free(ARRAY_SIZE(lis3->regulators),
+				lis3_dev.regulators);
+	return 0;
 }
 
 #ifdef CONFIG_PM