regulator: max1586: Implement get_voltage_sel callback

This is required since commit f7df20ec32
"regulator: core: Use list_voltage() to read single voltage regulators",
otherwise _regulator_get_voltage returns rdev->desc->ops->list_voltage(rdev, 0).

The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
the set up value. Thus this patch caches the setting when setting new voltage.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 41 insertions, 3 deletions

diff --git a/drivers/regulator/max1586.c b/drivers/regulator/max1586.c
index f67af3c1b963..ed2d3912efde 100644
--- a/drivers/regulator/max1586.c
+++ b/drivers/regulator/max1586.c
@@ -44,6 +44,9 @@ struct max1586_data {
         unsigned int min_uV;
         unsigned int max_uV;
 
+        unsigned int v3_curr_sel;
+        unsigned int v6_curr_sel;
+
         struct regulator_dev *rdev[0];
 };
 
@@ -63,31 +66,60 @@ static int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
  * R24 and R25=100kOhm as described in the data sheet.
  * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
  */
+static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
+{
+        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
+
+        return max1586->v3_curr_sel;
+}
+
 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
                                       unsigned selector)
 {
         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
         struct i2c_client *client = max1586->client;
+        int ret;
         u8 v3_prog;
 
         dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
                 regulator_list_voltage_linear(rdev, selector) / 1000);
 
         v3_prog = I2C_V3_SELECT | (u8) selector;
-        return i2c_smbus_write_byte(client, v3_prog);
+        ret = i2c_smbus_write_byte(client, v3_prog);
+        if (ret)
+                return ret;
+
+        max1586->v3_curr_sel = selector;
+
+        return 0;
+}
+
+static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
+{
+        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
+
+        return max1586->v6_curr_sel;
 }
 
 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
                                       unsigned int selector)
 {
-        struct i2c_client *client = rdev_get_drvdata(rdev);
+        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
+        struct i2c_client *client = max1586->client;
         u8 v6_prog;
+        int ret;
 
         dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
                 rdev->desc->volt_table[selector] / 1000);
 
         v6_prog = I2C_V6_SELECT | (u8) selector;
-        return i2c_smbus_write_byte(client, v6_prog);
+        ret = i2c_smbus_write_byte(client, v6_prog);
+        if (ret)
+                return ret;
+
+        max1586->v6_curr_sel = selector;
+
+        return 0;
 }
 
 /*
@@ -95,12 +127,14 @@ static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
  * the set up value.
  */
 static struct regulator_ops max1586_v3_ops = {
+        .get_voltage_sel = max1586_v3_get_voltage_sel,
         .set_voltage_sel = max1586_v3_set_voltage_sel,
         .list_voltage = regulator_list_voltage_linear,
         .map_voltage = regulator_map_voltage_linear,
 };
 
 static struct regulator_ops max1586_v6_ops = {
+        .get_voltage_sel = max1586_v6_get_voltage_sel,
         .set_voltage_sel = max1586_v6_set_voltage_sel,
         .list_voltage = regulator_list_voltage_table,
 };
@@ -148,6 +182,10 @@ static int __devinit max1586_pmic_probe(struct i2c_client *client,
         max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
         max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 
+        /* Set curr_sel to default voltage on power-up */
+        max1586->v3_curr_sel = 24; /* 1.3V */
+        max1586->v6_curr_sel = 0;
+
         rdev = max1586->rdev;
         for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
                 id = pdata->subdevs[i].id;