regulator: gpio-regulator: Allow use of GPIO controlled regulators though DT

Here we provide the GPIO Regulator driver with Device Tree capability, so
that when a platform is booting with DT instead of platform data we can
still make full use of it.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Lee Jones 2012-10-15 14:16:59 +01:00 committed by Mark Brown
parent ddffeb8c4d
commit 006694d099
2 changed files with 130 additions and 0 deletions

View File

@ -0,0 +1,36 @@
GPIO controlled regulators
Required properties:
- compatible : Must be "regulator-gpio".
Optional properties:
- gpio-enable : GPIO to use to enable/disable the regulator.
- gpios : GPIO group used to control voltage.
- states : Selection of available voltages and GPIO configs.
- startup-delay-us : Startup time in microseconds.
- enable-active-high : Polarity of GPIO is active high (default is low).
Any property defined as part of the core regulator binding defined in
regulator.txt can also be used.
Example:
mmciv: gpio-regulator {
compatible = "regulator-gpio";
regulator-name = "mmci-gpio-supply";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <2600000>;
regulator-boot-on;
gpio-enable = <&gpio0 23 0x4>;
gpios = <&gpio0 24 0x4
&gpio0 25 0x4>;
states = <1800000 0x3
2200000 0x2
2600000 0x1
2900000 0x0>;
startup-delay-us = <100000>;
enable-active-high;
};

View File

@ -28,9 +28,12 @@
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/gpio-regulator.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
struct gpio_regulator_data {
struct regulator_desc desc;
@ -129,6 +132,84 @@ static struct regulator_ops gpio_regulator_voltage_ops = {
.list_voltage = gpio_regulator_list_voltage,
};
struct gpio_regulator_config *
of_get_gpio_regulator_config(struct device *dev, struct device_node *np)
{
struct gpio_regulator_config *config;
struct property *prop;
const char *regtype;
int proplen, gpio, i;
config = devm_kzalloc(dev,
sizeof(struct gpio_regulator_config),
GFP_KERNEL);
if (!config)
return ERR_PTR(-ENOMEM);
config->init_data = of_get_regulator_init_data(dev, np);
if (!config->init_data)
return ERR_PTR(-EINVAL);
config->supply_name = config->init_data->constraints.name;
if (of_property_read_bool(np, "enable-active-high"))
config->enable_high = true;
if (of_property_read_bool(np, "enable-at-boot"))
config->enabled_at_boot = true;
of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
/* Fetch GPIOs. */
for (i = 0; ; i++)
if (of_get_named_gpio(np, "gpios", i) < 0)
break;
config->nr_gpios = i;
config->gpios = devm_kzalloc(dev,
sizeof(struct gpio) * config->nr_gpios,
GFP_KERNEL);
if (!config->gpios)
return ERR_PTR(-ENOMEM);
for (i = 0; config->nr_gpios; i++) {
gpio = of_get_named_gpio(np, "gpios", i);
if (gpio < 0)
break;
config->gpios[i].gpio = gpio;
}
/* Fetch states. */
prop = of_find_property(np, "states", NULL);
proplen = prop->length / sizeof(int);
config->states = devm_kzalloc(dev,
sizeof(struct gpio_regulator_state)
* (proplen / 2),
GFP_KERNEL);
if (!config->states)
return ERR_PTR(-ENOMEM);
for (i = 0; i < proplen / 2; i++) {
config->states[i].value =
be32_to_cpup((int *)prop->value + (i * 2));
config->states[i].gpios =
be32_to_cpup((int *)prop->value + (i * 2 + 1));
}
config->nr_states = i;
of_property_read_string(np, "regulator-type", &regtype);
if (!strncmp("voltage", regtype, 7))
config->type = REGULATOR_VOLTAGE;
else if (!strncmp("current", regtype, 7))
config->type = REGULATOR_CURRENT;
return config;
}
static struct regulator_ops gpio_regulator_current_ops = {
.get_current_limit = gpio_regulator_get_value,
.set_current_limit = gpio_regulator_set_current_limit,
@ -137,10 +218,17 @@ static struct regulator_ops gpio_regulator_current_ops = {
static int __devinit gpio_regulator_probe(struct platform_device *pdev)
{
struct gpio_regulator_config *config = pdev->dev.platform_data;
struct device_node *np = pdev->dev.of_node;
struct gpio_regulator_data *drvdata;
struct regulator_config cfg = { };
int ptr, ret, state;
if (np) {
config = of_get_gpio_regulator_config(&pdev->dev, np);
if (IS_ERR(config))
return PTR_ERR(config);
}
drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
GFP_KERNEL);
if (drvdata == NULL) {
@ -270,12 +358,18 @@ static int __devexit gpio_regulator_remove(struct platform_device *pdev)
return 0;
}
static const struct of_device_id regulator_gpio_of_match[] __devinitconst = {
{ .compatible = "regulator-gpio", },
{},
};
static struct platform_driver gpio_regulator_driver = {
.probe = gpio_regulator_probe,
.remove = __devexit_p(gpio_regulator_remove),
.driver = {
.name = "gpio-regulator",
.owner = THIS_MODULE,
.of_match_table = regulator_gpio_of_match,
},
};