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3acff11cef
When requesting the enable GPIO, the driver should do so with the
correct output level matching some expected state. This is especially
important if the regulator is a critical one, such as a supply for
the boot CPU. This is currently done by checking for the enable-at-boot
property, but this is not documented in the device tree binding, nor
does it match the common regulator properties.
Honor the common regulator-boot-on property by checking the boot_on
constraint setting within the DT probe path. This is the same as what
is done in the fixed regulator driver.
Also add a comment stating that the enable-at-boot property should not
be used.
Fixes: 006694d099
("regulator: gpio-regulator: Allow use of GPIO controlled regulators though DT")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20200720132809.26908-1-wens@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
376 lines
9.5 KiB
C
376 lines
9.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* gpio-regulator.c
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*
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* Copyright 2011 Heiko Stuebner <heiko@sntech.de>
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*
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* based on fixed.c
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*
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* Copyright 2008 Wolfson Microelectronics PLC.
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*
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* Copyright (c) 2009 Nokia Corporation
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* Roger Quadros <ext-roger.quadros@nokia.com>
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*
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* This is useful for systems with mixed controllable and
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* non-controllable regulators, as well as for allowing testing on
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* systems with no controllable regulators.
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*/
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/machine.h>
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#include <linux/regulator/of_regulator.h>
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#include <linux/regulator/gpio-regulator.h>
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#include <linux/gpio/consumer.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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struct gpio_regulator_data {
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struct regulator_desc desc;
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struct gpio_desc **gpiods;
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int nr_gpios;
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struct gpio_regulator_state *states;
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int nr_states;
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int state;
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};
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static int gpio_regulator_get_value(struct regulator_dev *dev)
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{
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struct gpio_regulator_data *data = rdev_get_drvdata(dev);
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int ptr;
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for (ptr = 0; ptr < data->nr_states; ptr++)
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if (data->states[ptr].gpios == data->state)
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return data->states[ptr].value;
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return -EINVAL;
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}
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static int gpio_regulator_set_voltage(struct regulator_dev *dev,
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int min_uV, int max_uV,
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unsigned *selector)
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{
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struct gpio_regulator_data *data = rdev_get_drvdata(dev);
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int ptr, target = 0, state, best_val = INT_MAX;
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for (ptr = 0; ptr < data->nr_states; ptr++)
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if (data->states[ptr].value < best_val &&
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data->states[ptr].value >= min_uV &&
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data->states[ptr].value <= max_uV) {
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target = data->states[ptr].gpios;
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best_val = data->states[ptr].value;
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if (selector)
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*selector = ptr;
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}
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if (best_val == INT_MAX)
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return -EINVAL;
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for (ptr = 0; ptr < data->nr_gpios; ptr++) {
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state = (target & (1 << ptr)) >> ptr;
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gpiod_set_value_cansleep(data->gpiods[ptr], state);
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}
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data->state = target;
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return 0;
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}
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static int gpio_regulator_list_voltage(struct regulator_dev *dev,
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unsigned selector)
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{
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struct gpio_regulator_data *data = rdev_get_drvdata(dev);
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if (selector >= data->nr_states)
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return -EINVAL;
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return data->states[selector].value;
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}
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static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
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int min_uA, int max_uA)
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{
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struct gpio_regulator_data *data = rdev_get_drvdata(dev);
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int ptr, target = 0, state, best_val = 0;
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for (ptr = 0; ptr < data->nr_states; ptr++)
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if (data->states[ptr].value > best_val &&
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data->states[ptr].value >= min_uA &&
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data->states[ptr].value <= max_uA) {
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target = data->states[ptr].gpios;
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best_val = data->states[ptr].value;
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}
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if (best_val == 0)
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return -EINVAL;
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for (ptr = 0; ptr < data->nr_gpios; ptr++) {
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state = (target & (1 << ptr)) >> ptr;
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gpiod_set_value_cansleep(data->gpiods[ptr], state);
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}
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data->state = target;
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return 0;
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}
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static const struct regulator_ops gpio_regulator_voltage_ops = {
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.get_voltage = gpio_regulator_get_value,
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.set_voltage = gpio_regulator_set_voltage,
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.list_voltage = gpio_regulator_list_voltage,
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};
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static struct gpio_regulator_config *
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of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
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const struct regulator_desc *desc)
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{
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struct gpio_regulator_config *config;
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const char *regtype;
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int proplen, i;
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int ngpios;
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int ret;
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config = devm_kzalloc(dev,
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sizeof(struct gpio_regulator_config),
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GFP_KERNEL);
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if (!config)
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return ERR_PTR(-ENOMEM);
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config->init_data = of_get_regulator_init_data(dev, np, desc);
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if (!config->init_data)
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return ERR_PTR(-EINVAL);
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config->supply_name = config->init_data->constraints.name;
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if (config->init_data->constraints.boot_on)
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config->enabled_at_boot = true;
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/*
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* Do not use: undocumented device tree property.
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* This is kept around solely for device tree ABI stability.
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*/
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if (of_property_read_bool(np, "enable-at-boot"))
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config->enabled_at_boot = true;
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of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
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/* Fetch GPIO init levels */
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ngpios = gpiod_count(dev, NULL);
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if (ngpios > 0) {
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config->gflags = devm_kzalloc(dev,
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sizeof(enum gpiod_flags)
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* ngpios,
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GFP_KERNEL);
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if (!config->gflags)
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return ERR_PTR(-ENOMEM);
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for (i = 0; i < ngpios; i++) {
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u32 val;
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ret = of_property_read_u32_index(np, "gpios-states", i,
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&val);
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/* Default to high per specification */
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if (ret)
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config->gflags[i] = GPIOD_OUT_HIGH;
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else
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config->gflags[i] =
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val ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
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}
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}
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config->ngpios = ngpios;
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/* Fetch states. */
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proplen = of_property_count_u32_elems(np, "states");
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if (proplen < 0) {
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dev_err(dev, "No 'states' property found\n");
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return ERR_PTR(-EINVAL);
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}
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config->states = devm_kcalloc(dev,
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proplen / 2,
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sizeof(struct gpio_regulator_state),
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GFP_KERNEL);
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if (!config->states)
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return ERR_PTR(-ENOMEM);
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for (i = 0; i < proplen / 2; i++) {
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of_property_read_u32_index(np, "states", i * 2,
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&config->states[i].value);
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of_property_read_u32_index(np, "states", i * 2 + 1,
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&config->states[i].gpios);
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}
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config->nr_states = i;
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config->type = REGULATOR_VOLTAGE;
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ret = of_property_read_string(np, "regulator-type", ®type);
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if (ret >= 0) {
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if (!strncmp("voltage", regtype, 7))
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config->type = REGULATOR_VOLTAGE;
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else if (!strncmp("current", regtype, 7))
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config->type = REGULATOR_CURRENT;
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else
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dev_warn(dev, "Unknown regulator-type '%s'\n",
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regtype);
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}
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return config;
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}
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static const struct regulator_ops gpio_regulator_current_ops = {
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.get_current_limit = gpio_regulator_get_value,
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.set_current_limit = gpio_regulator_set_current_limit,
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};
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static int gpio_regulator_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct gpio_regulator_config *config = dev_get_platdata(dev);
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struct device_node *np = dev->of_node;
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struct gpio_regulator_data *drvdata;
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struct regulator_config cfg = { };
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struct regulator_dev *rdev;
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enum gpiod_flags gflags;
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int ptr, ret, state, i;
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drvdata = devm_kzalloc(dev, sizeof(struct gpio_regulator_data),
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GFP_KERNEL);
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if (drvdata == NULL)
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return -ENOMEM;
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if (np) {
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config = of_get_gpio_regulator_config(dev, np,
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&drvdata->desc);
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if (IS_ERR(config))
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return PTR_ERR(config);
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}
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drvdata->desc.name = devm_kstrdup(dev, config->supply_name, GFP_KERNEL);
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if (drvdata->desc.name == NULL) {
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dev_err(dev, "Failed to allocate supply name\n");
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return -ENOMEM;
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}
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drvdata->gpiods = devm_kzalloc(dev, sizeof(struct gpio_desc *),
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GFP_KERNEL);
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if (!drvdata->gpiods)
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return -ENOMEM;
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for (i = 0; i < config->ngpios; i++) {
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drvdata->gpiods[i] = devm_gpiod_get_index(dev,
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NULL,
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i,
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config->gflags[i]);
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if (IS_ERR(drvdata->gpiods[i]))
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return PTR_ERR(drvdata->gpiods[i]);
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/* This is good to know */
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gpiod_set_consumer_name(drvdata->gpiods[i], drvdata->desc.name);
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}
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drvdata->nr_gpios = config->ngpios;
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drvdata->states = devm_kmemdup(dev,
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config->states,
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config->nr_states *
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sizeof(struct gpio_regulator_state),
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GFP_KERNEL);
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if (drvdata->states == NULL) {
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dev_err(dev, "Failed to allocate state data\n");
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return -ENOMEM;
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}
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drvdata->nr_states = config->nr_states;
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drvdata->desc.owner = THIS_MODULE;
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drvdata->desc.enable_time = config->startup_delay;
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/* handle regulator type*/
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switch (config->type) {
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case REGULATOR_VOLTAGE:
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drvdata->desc.type = REGULATOR_VOLTAGE;
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drvdata->desc.ops = &gpio_regulator_voltage_ops;
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drvdata->desc.n_voltages = config->nr_states;
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break;
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case REGULATOR_CURRENT:
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drvdata->desc.type = REGULATOR_CURRENT;
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drvdata->desc.ops = &gpio_regulator_current_ops;
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break;
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default:
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dev_err(dev, "No regulator type set\n");
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return -EINVAL;
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}
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/* build initial state from gpio init data. */
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state = 0;
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for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
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if (config->gflags[ptr] == GPIOD_OUT_HIGH)
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state |= (1 << ptr);
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}
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drvdata->state = state;
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cfg.dev = dev;
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cfg.init_data = config->init_data;
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cfg.driver_data = drvdata;
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cfg.of_node = np;
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/*
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* The signal will be inverted by the GPIO core if flagged so in the
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* descriptor.
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*/
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if (config->enabled_at_boot)
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gflags = GPIOD_OUT_HIGH | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
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else
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gflags = GPIOD_OUT_LOW | GPIOD_FLAGS_BIT_NONEXCLUSIVE;
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cfg.ena_gpiod = gpiod_get_optional(dev, "enable", gflags);
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if (IS_ERR(cfg.ena_gpiod))
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return PTR_ERR(cfg.ena_gpiod);
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rdev = devm_regulator_register(dev, &drvdata->desc, &cfg);
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if (IS_ERR(rdev)) {
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ret = PTR_ERR(rdev);
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dev_err(dev, "Failed to register regulator: %d\n", ret);
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return ret;
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}
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platform_set_drvdata(pdev, drvdata);
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return 0;
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}
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#if defined(CONFIG_OF)
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static const struct of_device_id regulator_gpio_of_match[] = {
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{ .compatible = "regulator-gpio", },
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{},
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};
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MODULE_DEVICE_TABLE(of, regulator_gpio_of_match);
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#endif
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static struct platform_driver gpio_regulator_driver = {
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.probe = gpio_regulator_probe,
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.driver = {
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.name = "gpio-regulator",
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.of_match_table = of_match_ptr(regulator_gpio_of_match),
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},
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};
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static int __init gpio_regulator_init(void)
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{
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return platform_driver_register(&gpio_regulator_driver);
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}
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subsys_initcall(gpio_regulator_init);
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static void __exit gpio_regulator_exit(void)
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{
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platform_driver_unregister(&gpio_regulator_driver);
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}
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module_exit(gpio_regulator_exit);
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MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
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MODULE_DESCRIPTION("gpio voltage regulator");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:gpio-regulator");
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