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375 lines
9.5 KiB
375 lines
9.5 KiB
// 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 <[email protected]> |
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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 <[email protected]> |
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* |
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* Copyright (c) 2009 Nokia Corporation |
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* Roger Quadros <[email protected]> |
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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 <[email protected]>"); |
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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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