// SPDX-License-Identifier: GPL-2.0-or-later
/*
* gpio-regulator.c
*
* Copyright 2011 Heiko Stuebner <[email protected]>
*
* based on fixed.c
*
* Copyright 2008 Wolfson Microelectronics PLC.
*
* Author: Mark Brown <[email protected]>
*
* Copyright (c) 2009 Nokia Corporation
* Roger Quadros <[email protected]>
*
* This is useful for systems with mixed controllable and
* non-controllable regulators, as well as for allowing testing on
* systems with no controllable regulators.
*/
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/module.h>
#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/consumer.h>
#include <linux/slab.h>
#include <linux/of.h>
struct gpio_regulator_data {
struct regulator_desc desc;
struct gpio_desc **gpiods;
int nr_gpios;
struct gpio_regulator_state *states;
int nr_states;
int state;
};
static int gpio_regulator_get_value(struct regulator_dev *dev)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
int ptr;
for (ptr = 0; ptr < data->nr_states; ptr++)
if (data->states[ptr].gpios == data->state)
return data->states[ptr].value;
return -EINVAL;
}
static int gpio_regulator_set_voltage(struct regulator_dev *dev,
int min_uV, int max_uV,
unsigned *selector)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
int ptr, target = 0, state, best_val = INT_MAX;
for (ptr = 0; ptr < data->nr_states; ptr++)
if (data->states[ptr].value < best_val &&
data->states[ptr].value >= min_uV &&
data->states[ptr].value <= max_uV) {
target = data->states[ptr].gpios;
best_val = data->states[ptr].value;
if (selector)
*selector = ptr;
}
if (best_val == INT_MAX)
return -EINVAL;
for (ptr = 0; ptr < data->nr_gpios; ptr++) {
state = (target & (1 << ptr)) >> ptr;
gpiod_set_value_cansleep(data->gpiods[ptr], state);
}
data->state = target;
return 0;
}
static int gpio_regulator_list_voltage(struct regulator_dev *dev,
unsigned selector)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
if (selector >= data->nr_states)
return -EINVAL;
return data->states[selector].value;
}
static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
int min_uA, int max_uA)
{
struct gpio_regulator_data *data = rdev_get_drvdata(dev);
int ptr, target = 0, state, best_val = 0;
for (ptr = 0; ptr < data->nr_states; ptr++)
if (data->states[ptr].value > best_val &&
data->states[ptr].value >= min_uA &&
data->states[ptr].value <= max_uA) {
target = data->states[ptr].gpios;
best_val = data->states[ptr].value;
}
if (best_val == 0)
return -EINVAL;
for (ptr = 0; ptr < data->nr_gpios; ptr++) {
state = (target & (1 << ptr)) >> ptr;
gpiod_set_value_cansleep(data->gpiods[ptr], state);
}
data->state = target;
return 0;
}
static const struct regulator_ops gpio_regulator_voltage_ops = {
.get_voltage = gpio_regulator_get_value,
.set_voltage = gpio_regulator_set_voltage,
.list_voltage = gpio_regulator_list_voltage,
};
static struct gpio_regulator_config *
of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
const struct regulator_desc *desc)
{
struct gpio_regulator_config *config;
const char *regtype;
int proplen, i;
int ngpios;
int ret;
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, desc);
if (!config->init_data)
return ERR_PTR(-EINVAL);
config->supply_name = config->init_data->constraints.name;
if (config->init_data->constraints.boot_on)
config->enabled_at_boot = true;
/*
* Do not use: undocumented device tree property.
* This is kept around solely for device tree ABI stability.
*/
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);
/* Fetch GPIO init levels */
ngpios = gpiod_count(dev, NULL);
if (ngpios > 0) {
config->gflags = devm_kzalloc(dev,
sizeof(enum gpiod_flags)
* ngpios,
GFP_KERNEL);
if (!config->gflags)
return ERR_PTR(-ENOMEM);
for (i = 0; i < ngpios; i++) {
u32 val;
ret = of_property_read_u32_index(np, "gpios-states", i,
&val);
/* Default to high per specification */
if (ret)
config->gflags[i] = GPIOD_OUT_HIGH;
else
config->gflags[i] =
val ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
}
}
config->ngpios = ngpios;
/* Fetch states. */
proplen = of_property_count_u32_elems(np, "states");
if (proplen < 0) {
dev_err(dev, "No 'states' property found\n");
return ERR_PTR(-EINVAL);
}
config->states = devm_kcalloc(dev,
proplen / 2,
sizeof(struct gpio_regulator_state),
GFP_KERNEL);
if (!config->states)
return ERR_PTR(-ENOMEM);
for (i = 0; i < proplen / 2; i++) {
of_property_read_u32_index(np, "states", i * 2,
&config->states[i].value);
of_property_read_u32_index(np, "states", i * 2 + 1,
&config->states[i].gpios);
}
config->nr_states = i;
config->type = REGULATOR_VOLTAGE;
ret = of_property_read_string(np, "regulator-type", ®type);
if (ret >= 0) {
if (!strncmp("voltage", regtype, 7))
config->type = REGULATOR_VOLTAGE;
else if (!strncmp("current", regtype, 7))
config->type = REGULATOR_CURRENT;
else
dev_warn(dev, "Unknown regulator-type '%s'\n",
regtype);
}
if (of_property_present(np, "vin-supply"))
config->input_supply = "vin";
return config;
}
static const struct regulator_ops gpio_regulator_current_ops = {
.get_current_limit = gpio_regulator_get_value,
.set_current_limit = gpio_regulator_set_current_limit,
};
static int gpio_regulator_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct gpio_regulator_config *config = dev_get_platdata(dev);
struct device_node *np = dev->of_node;
struct gpio_regulator_data *drvdata;
struct regulator_config cfg = { };
struct regulator_dev *rdev;
enum gpiod_flags gflags;
int ptr, ret, state, i;
drvdata = devm_kzalloc(dev, sizeof(struct gpio_regulator_data),
GFP_KERNEL);
if (drvdata == NULL)
return -ENOMEM;
if (np) {
config = of_get_gpio_regulator_config(dev, np,
&drvdata->desc);
if (IS_ERR(config))
return PTR_ERR(config);
}
drvdata->desc.name = devm_kstrdup(dev, config->supply_name, GFP_KERNEL);
if (drvdata->desc.name == NULL) {
dev_err(dev, "Failed to allocate supply name\n");
return -ENOMEM;
}
drvdata->gpiods = devm_kzalloc(dev, sizeof(struct gpio_desc *),
GFP_KERNEL);
if (config->input_supply) {
drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
config->input_supply,
GFP_KERNEL);
if (!drvdata->desc.supply_name) {
dev_err(&pdev->dev,
"Failed to allocate input supply\n");
return -ENOMEM;
}
}
if (!drvdata->gpiods)
return -ENOMEM;
for (i = 0; i < config->ngpios; i++) {
drvdata->gpiods[i] = devm_gpiod_get_index(dev,
NULL,
i,
config->gflags[i]);
if (IS_ERR(drvdata->gpiods[i]))
return PTR_ERR(drvdata->gpiods[i]);
/* This is good to know */
gpiod_set_consumer_name(drvdata->gpiods[i], drvdata->desc.name);
}
drvdata->nr_gpios = config->ngpios;
drvdata->states = devm_kmemdup(dev,
config->states,
config->nr_states *
sizeof(struct gpio_regulator_state),
GFP_KERNEL);
if (drvdata->states == NULL) {
dev_err(dev, "Failed to allocate state data\n");
return -ENOMEM;
}
drvdata->nr_states = config->nr_states;
drvdata->desc.owner = THIS_MODULE;
drvdata->desc.enable_time = config->startup_delay;
/* handle regulator type*/
switch (config->type) {
case REGULATOR_VOLTAGE:
drvdata->desc.type = REGULATOR_VOLTAGE;
drvdata->desc.ops = &gpio_regulator_voltage_ops;
drvdata->desc.n_voltages = config->nr_states;
break;
case REGULATOR_CURRENT:
drvdata->desc.type = REGULATOR_CURRENT;
drvdata->desc.ops = &gpio_regulator_current_ops;
break;
default:
dev_err(dev, "No regulator type set\n");
return -EINVAL;
}
/* build initial state from gpio init data. */
state = 0;
for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
if (config->gflags[ptr] == GPIOD_OUT_HIGH)
state |= (1 << ptr);
}
drvdata->state = state;
cfg.dev = dev;
cfg.init_data = config->init_data;
cfg.driver_data = drvdata;
cfg.of_node = np;
/*
* The signal will be inverted by the GPIO core if flagged so in the
* descriptor.
*/
if (config->enabled_at_boot)
gflags = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
else
gflags = GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
cfg.ena_gpiod = gpiod_get_optional(dev, "enable", gflags);
if (IS_ERR(cfg.ena_gpiod))
return PTR_ERR(cfg.ena_gpiod);
rdev = devm_regulator_register(dev, &drvdata->desc, &cfg);
if (IS_ERR(rdev)) {
ret = PTR_ERR(rdev);
dev_err(dev, "Failed to register regulator: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, drvdata);
return 0;
}
#if defined(CONFIG_OF)
static const struct of_device_id regulator_gpio_of_match[] = {
{ .compatible = "regulator-gpio", },
{},
};
MODULE_DEVICE_TABLE(of, regulator_gpio_of_match);
#endif
static struct platform_driver gpio_regulator_driver = {
.probe = gpio_regulator_probe,
.driver = {
.name = "gpio-regulator",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
.of_match_table = of_match_ptr(regulator_gpio_of_match),
},
};
static int __init gpio_regulator_init(void)
{
return platform_driver_register(&gpio_regulator_driver);
}
subsys_initcall(gpio_regulator_init);
static void __exit gpio_regulator_exit(void)
{
platform_driver_unregister(&gpio_regulator_driver);
}
module_exit(gpio_regulator_exit);
MODULE_AUTHOR("Heiko Stuebner <[email protected]>");
MODULE_DESCRIPTION("gpio voltage regulator");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-regulator");
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