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regulator: max8973: add mechanism to enable/disable through GPIO 

MAX8973 supports the voltage output enable/disable through its EN
pin. This EN pin can be connected through GPIO from host processor.
Add support to provide GPIO number from platform/DT and if it is
valid GPIO then enable external control default.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Laxman Dewangan 2015-04-23 16:10:24 +05:30 committed by Mark Brown
parent c2ffa97378
commit 69eb0980ab
3 changed files with 29 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/devicetree/bindings/regulator/max8973-regulator.txt
View File

@ -12,6 +12,8 @@ Optional properties:
-maxim,externally-enable: boolean, externally control the regulator output
enable/disable.
-maxim,enable-gpio: GPIO for enable control. If the valid GPIO is provided
then externally enable control will be considered.
-maxim,dvs-gpio: GPIO which is connected to DVS pin of device.
-maxim,dvs-default-state: Default state of GPIO during initialisation.
1 for HIGH and 0 for LOW.

29
drivers/regulator/max8973-regulator.c
View File

@ -96,6 +96,7 @@ struct max8973_chip {
struct regulator_desc desc;
struct regmap *regmap;
bool enable_external_control;
int enable_gpio;
int dvs_gpio;
int lru_index[MAX8973_MAX_VOUT_REG];
int curr_vout_val[MAX8973_MAX_VOUT_REG];
@ -379,6 +380,7 @@ static struct max8973_regulator_platform_data *max8973_parse_dt(
pdata->enable_ext_control = of_property_read_bool(np,
"maxim,externally-enable");
pdata->enable_gpio = of_get_named_gpio(np, "maxim,enable-gpio", 0);
pdata->dvs_gpio = of_get_named_gpio(np, "maxim,dvs-gpio", 0);
ret = of_property_read_u32(np, "maxim,dvs-default-state", &pval);
@ -409,6 +411,7 @@ static int max8973_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct max8973_regulator_platform_data *pdata;
struct regulator_init_data *ridata;
struct regulator_config config = { };
struct regulator_dev *rdev;
struct max8973_chip *max;
@ -427,7 +430,8 @@ static int max8973_probe(struct i2c_client *client,
return -EIO;
}
if (pdata->dvs_gpio == -EPROBE_DEFER)
if ((pdata->dvs_gpio == -EPROBE_DEFER) ||
(pdata->enable_gpio == -EPROBE_DEFER))
return -EPROBE_DEFER;
max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
@ -453,6 +457,15 @@ static int max8973_probe(struct i2c_client *client,
max->desc.uV_step = MAX8973_VOLATGE_STEP;
max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;
max->dvs_gpio = (pdata->dvs_gpio) ? pdata->dvs_gpio : -EINVAL;
max->enable_gpio = (pdata->enable_gpio) ? pdata->enable_gpio : -EINVAL;
max->enable_external_control = pdata->enable_ext_control;
max->curr_gpio_val = pdata->dvs_def_state;
max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
if (gpio_is_valid(max->enable_gpio))
max->enable_external_control = true;
if (!pdata->enable_ext_control) {
max->desc.enable_reg = MAX8973_VOUT;
max->desc.enable_mask = MAX8973_VOUT_ENABLE;
@ -461,11 +474,6 @@ static int max8973_probe(struct i2c_client *client,
max->ops.is_enabled = regulator_is_enabled_regmap;
}
max->dvs_gpio = (pdata->dvs_gpio) ? pdata->dvs_gpio : -EINVAL;
max->enable_external_control = pdata->enable_ext_control;
max->curr_gpio_val = pdata->dvs_def_state;
max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
max->lru_index[0] = max->curr_vout_reg;
if (gpio_is_valid(max->dvs_gpio)) {
@ -509,6 +517,15 @@ static int max8973_probe(struct i2c_client *client,
config.of_node = client->dev.of_node;
config.regmap = max->regmap;
if (gpio_is_valid(max->enable_gpio)) {
ridata = pdata->reg_init_data;
config.ena_gpio_flags = GPIOF_OUT_INIT_LOW;
if (ridata && (ridata->constraints.always_on ||
ridata->constraints.boot_on))
config.ena_gpio_flags = GPIOF_OUT_INIT_HIGH;
config.ena_gpio = max->enable_gpio;
}
/* Register the regulators */
rdev = devm_regulator_register(&client->dev, &max->desc, &config);
if (IS_ERR(rdev)) {

4
include/linux/regulator/max8973-regulator.h
View File

@ -58,6 +58,9 @@
* control signal from EN input pin. If it is false then
* voltage output will be enabled/disabled through EN bit of
* device register.
* @enable_gpio: Enable GPIO. If EN pin is controlled through GPIO from host
* then GPIO number can be provided. If no GPIO controlled then
* it should be -1.
* @dvs_gpio: GPIO for dvs. It should be -1 if this is tied with fixed logic.
* @dvs_def_state: Default state of dvs. 1 if it is high else 0.
*/
@ -65,6 +68,7 @@ struct max8973_regulator_platform_data {
struct regulator_init_data *reg_init_data;
unsigned long control_flags;
bool enable_ext_control;
int enable_gpio;
int dvs_gpio;
unsigned dvs_def_state:1;
};