regulator: max8973: add enable/disable regulator support

Add enable/disable regulator support instead of using
core api to save and restore vout and vout dfs values.

Change-Id: I252c88dfabed4fbd0b6a8dd2983fdeabc4fd264e
Signed-off-by: Venkat Reddy Talla <vreddytalla@nvidia.com>
Reviewed-on: http://git-master/r/709798
(cherry picked from commit f5c1083a2ff97e824c6b2d8c1416eb4572765261)
Reviewed-on: http://git-master/r/710191
Tested-by: Gagan Grover <ggrover@nvidia.com>
Reviewed-by: Mitch Luban <mluban@nvidia.com>

diff --git a/drivers/regulator/max8973-regulator.c b/drivers/regulator/max8973-regulator.c
index 0ed57bc59dfdb6a3296d72f3b761cbf5b8c4a34d..e9fdd0b86fce1615a33d801e45cfbba1718c878a 100644 (file)
--- a/drivers/regulator/max8973-regulator.c
+++ b/drivers/regulator/max8973-regulator.c
@@ -3,7 +3,7 @@
  *
  * Regulator driver for MAXIM 8973 DC-DC step-down switching regulator.
  *
- * Copyright (c) 2012, NVIDIA Corporation.
+ * Copyright (c) 2012-2015, NVIDIA CORPORATION.  All rights reserved.
  *
  * Author: Laxman Dewangan <ldewangan@nvidia.com>
  *
@@ -52,6 +52,7 @@
 #define MAX8973_CHIPID2                                        0x5
 
 #define MAX8973_MAX_VOUT_REG                           2
+#define MAX8973_MAX_REG                                        4
 
 /* MAX8973_VOUT */
 #define MAX8973_VOUT_ENABLE                            BIT(7)
@@ -120,10 +121,12 @@ struct max8973_chip {
        int enable_gpio;
        int lru_index[MAX8973_MAX_VOUT_REG];
        int curr_vout_val[MAX8973_MAX_VOUT_REG];
+       int cache_reg_val[MAX8973_MAX_REG];
        int curr_vout_reg;
        int sleep_vout_reg;
        int curr_gpio_val;
        int junction_temp_warning;
+       int enable_state;
        struct regulator_ops ops;
        enum device_id id;
        int irq;
@@ -320,6 +323,81 @@ static int max8973_set_ramp_delay(struct regulator_dev *rdev,
        return ret_val;
 }
 
+int max8973_regulator_enable(struct regulator_dev *rdev)
+{
+       struct max8973_chip *max = rdev_get_drvdata(rdev);
+       int ret;
+       int i;
+
+       if (gpio_is_valid(max->enable_gpio)) {
+               for (i = 0; i < MAX8973_MAX_REG; ++i) {
+                       ret = regmap_write(max->regmap, i,
+                                                max->cache_reg_val[i]);
+                       if (ret < 0) {
+                               dev_err(max->dev,
+                                       "reg %d write failed, err = %d\n",
+                                       i, ret);
+                               return ret;
+                       }
+               }
+       }
+
+       ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
+                               MAX8973_VOUT_ENABLE, MAX8973_VOUT_ENABLE);
+       if (ret < 0) {
+               dev_err(max->dev, "reg %d update failed, err = %d\n",
+                       MAX8973_VOUT, ret);
+               return ret;
+       }
+
+       if (gpio_is_valid(max->enable_gpio))
+               gpio_set_value_cansleep(max->enable_gpio, 1);
+
+       max->enable_state = true;
+       return 0;
+}
+
+int max8973_regulator_disable(struct regulator_dev *rdev)
+{
+       struct max8973_chip *max = rdev_get_drvdata(rdev);
+       int ret;
+       int i;
+
+       if (gpio_is_valid(max->enable_gpio)) {
+               for (i = 0; i < MAX8973_MAX_REG; ++i) {
+                       ret = regmap_read(max->regmap, i,
+                                               &max->cache_reg_val[i]);
+                       if (ret < 0) {
+                               dev_err(max->dev,
+                                       "reg %d read failed, err = %d\n",
+                                       i, ret);
+                               return ret;
+                       }
+               }
+               gpio_set_value_cansleep(max->enable_gpio, 0);
+               max->enable_state = false;
+       } else {
+               ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
+                                               MAX8973_VOUT_ENABLE, 0);
+               if (ret < 0) {
+                       dev_err(max->dev,
+                               "reg %d update failed, err = %d\n",
+                               MAX8973_VOUT, ret);
+                       return ret;
+               }
+       }
+
+       max->enable_state = false;
+       return 0;
+}
+
+static int max8973_regulator_is_enabled(struct regulator_dev *rdev)
+{
+       struct max8973_chip *max = rdev_get_drvdata(rdev);
+
+       return max->enable_state;
+}
+
 static const struct regulator_ops max8973_dcdc_ops = {
        .get_voltage_sel        = max8973_dcdc_get_voltage_sel,
        .set_voltage_sel        = max8973_dcdc_set_voltage_sel,
@@ -329,6 +407,9 @@ static const struct regulator_ops max8973_dcdc_ops = {
        .set_voltage_time_sel   = regulator_set_voltage_time_sel,
        .set_ramp_delay         = max8973_set_ramp_delay,
        .set_sleep_voltage_sel  = max8973_dcdc_set_sleep_voltage_sel,
+       .enable                 = max8973_regulator_enable,
+       .disable                = max8973_regulator_disable,
+       .is_enabled             = max8973_regulator_is_enabled,
 };
 
 static int max8973_init_dcdc(struct max8973_chip *max,
@@ -603,6 +684,8 @@ static int max8973_probe(struct i2c_client *client,
        struct max8973_chip *max;
        unsigned int chip_id;
        int ret;
+       int reg;
+       int gpio_flags;
 
        pdata = client->dev.platform_data;
        if (!pdata && client->dev.of_node)
@@ -666,16 +749,20 @@ static int max8973_probe(struct i2c_client *client,
        if (!pdata->enable_ext_control) {
                max->desc.enable_reg = MAX8973_VOUT;
                max->desc.enable_mask = MAX8973_VOUT_ENABLE;
-               max->ops.enable = regulator_enable_regmap;
-               max->ops.disable = regulator_disable_regmap;
-               max->ops.is_enabled = regulator_is_enabled_regmap;
        } else if (gpio_is_valid(pdata->enable_gpio)) {
-               config.ena_gpio = pdata->enable_gpio;
-
+               gpio_flags = GPIOF_OUT_INIT_LOW;
                if (pdata->reg_init_data) {
                        if (pdata->reg_init_data->constraints.always_on ||
                                pdata->reg_init_data->constraints.boot_on)
-                               config.ena_gpio_flags = GPIOF_OUT_INIT_HIGH;
+                               gpio_flags = GPIOF_OUT_INIT_HIGH;
+               }
+               ret = devm_gpio_request_one(&client->dev, pdata->enable_gpio,
+                               gpio_flags, "max8973-enable-gpio");
+               if (ret) {
+                       dev_err(&client->dev,
+                               "gpio_request for gpio %d failed, err = %d\n",
+                               pdata->enable_gpio, ret);
+                       return ret;
                }
        }
 
@@ -694,7 +781,6 @@ static int max8973_probe(struct i2c_client *client,
        max->lru_index[0] = max->curr_vout_reg;
 
        if (gpio_is_valid(max->dvs_gpio)) {
-               int gpio_flags;
                int i;
 
                gpio_flags = (pdata->dvs_def_state) ?
@@ -726,6 +812,19 @@ static int max8973_probe(struct i2c_client *client,
                }
        }
 
+       if (gpio_is_valid(max->enable_gpio)) {
+               for (reg = 0; reg < MAX8973_MAX_REG; ++reg) {
+                       ret = regmap_read(max->regmap, reg,
+                                       &max->cache_reg_val[reg]);
+                       if (ret < 0) {
+                               dev_err(max->dev,
+                                       "reg %d read failed, err = %d\n",
+                                       reg, ret);
+                               return ret;
+                       }
+               }
+       }
+
        config.dev = &client->dev;
        config.init_data = pdata->reg_init_data;
        config.driver_data = max;