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>

1 files changed, 54 insertions, 1 deletions

diff --git a/drivers/hwmon/lis3lv02d_i2c.c b/drivers/hwmon/lis3lv02d_i2c.c
index d52095603e0..ec35c87819c 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 @@ static int lis3_i2c_init(struct lis3lv02d *lis3)
         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 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
         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 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
                         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 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
         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