![Mark Brown](/assets/img/avatar_default.png)
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
359 lines
8.8 KiB
C
359 lines
8.8 KiB
C
/*
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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 program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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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/gpio-regulator.h>
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#include <linux/gpio.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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struct gpio_regulator_data {
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struct regulator_desc desc;
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struct regulator_dev *dev;
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int enable_gpio;
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bool enable_high;
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bool is_enabled;
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unsigned startup_delay;
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struct gpio *gpios;
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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_is_enabled(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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return data->is_enabled;
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}
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static int gpio_regulator_enable(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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if (gpio_is_valid(data->enable_gpio)) {
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gpio_set_value_cansleep(data->enable_gpio, data->enable_high);
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data->is_enabled = true;
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}
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return 0;
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}
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static int gpio_regulator_disable(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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if (gpio_is_valid(data->enable_gpio)) {
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gpio_set_value_cansleep(data->enable_gpio, !data->enable_high);
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data->is_enabled = false;
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}
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return 0;
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}
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static int gpio_regulator_enable_time(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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return data->startup_delay;
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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_value(struct regulator_dev *dev,
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int min, int max)
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{
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struct gpio_regulator_data *data = rdev_get_drvdata(dev);
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int ptr, target, state;
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target = -1;
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for (ptr = 0; ptr < data->nr_states; ptr++)
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if (data->states[ptr].value >= min &&
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data->states[ptr].value <= max)
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target = data->states[ptr].gpios;
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if (target < 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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gpio_set_value(data->gpios[ptr].gpio, 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_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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return gpio_regulator_set_value(dev, min_uV, max_uV);
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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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return gpio_regulator_set_value(dev, min_uA, max_uA);
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}
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static struct regulator_ops gpio_regulator_voltage_ops = {
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.is_enabled = gpio_regulator_is_enabled,
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.enable = gpio_regulator_enable,
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.disable = gpio_regulator_disable,
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.enable_time = gpio_regulator_enable_time,
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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 regulator_ops gpio_regulator_current_ops = {
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.is_enabled = gpio_regulator_is_enabled,
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.enable = gpio_regulator_enable,
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.disable = gpio_regulator_disable,
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.enable_time = gpio_regulator_enable_time,
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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 __devinit gpio_regulator_probe(struct platform_device *pdev)
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{
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struct gpio_regulator_config *config = pdev->dev.platform_data;
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struct gpio_regulator_data *drvdata;
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int ptr, ret, state;
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drvdata = kzalloc(sizeof(struct gpio_regulator_data), GFP_KERNEL);
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if (drvdata == NULL) {
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dev_err(&pdev->dev, "Failed to allocate device data\n");
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return -ENOMEM;
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}
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drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
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if (drvdata->desc.name == NULL) {
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dev_err(&pdev->dev, "Failed to allocate supply name\n");
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ret = -ENOMEM;
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goto err;
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}
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drvdata->gpios = kmemdup(config->gpios,
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config->nr_gpios * sizeof(struct gpio),
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GFP_KERNEL);
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if (drvdata->gpios == NULL) {
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dev_err(&pdev->dev, "Failed to allocate gpio data\n");
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ret = -ENOMEM;
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goto err_name;
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}
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drvdata->states = kmemdup(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(&pdev->dev, "Failed to allocate state data\n");
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ret = -ENOMEM;
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goto err_memgpio;
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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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/* 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(&pdev->dev, "No regulator type set\n");
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ret = -EINVAL;
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goto err_memgpio;
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break;
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}
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drvdata->enable_gpio = config->enable_gpio;
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drvdata->startup_delay = config->startup_delay;
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if (gpio_is_valid(config->enable_gpio)) {
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drvdata->enable_high = config->enable_high;
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ret = gpio_request(config->enable_gpio, config->supply_name);
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if (ret) {
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dev_err(&pdev->dev,
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"Could not obtain regulator enable GPIO %d: %d\n",
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config->enable_gpio, ret);
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goto err_memstate;
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}
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/* set output direction without changing state
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* to prevent glitch
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*/
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if (config->enabled_at_boot) {
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drvdata->is_enabled = true;
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ret = gpio_direction_output(config->enable_gpio,
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config->enable_high);
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} else {
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drvdata->is_enabled = false;
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ret = gpio_direction_output(config->enable_gpio,
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!config->enable_high);
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}
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if (ret) {
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dev_err(&pdev->dev,
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"Could not configure regulator enable GPIO %d direction: %d\n",
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config->enable_gpio, ret);
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goto err_enablegpio;
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}
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} else {
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/* Regulator without GPIO control is considered
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* always enabled
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*/
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drvdata->is_enabled = true;
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}
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drvdata->nr_gpios = config->nr_gpios;
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ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
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if (ret) {
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dev_err(&pdev->dev,
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"Could not obtain regulator setting GPIOs: %d\n", ret);
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goto err_enablegpio;
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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->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
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state |= (1 << ptr);
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}
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drvdata->state = state;
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drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
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config->init_data, drvdata);
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if (IS_ERR(drvdata->dev)) {
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ret = PTR_ERR(drvdata->dev);
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dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
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goto err_stategpio;
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}
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platform_set_drvdata(pdev, drvdata);
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return 0;
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err_stategpio:
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gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
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err_enablegpio:
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if (gpio_is_valid(config->enable_gpio))
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gpio_free(config->enable_gpio);
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err_memstate:
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kfree(drvdata->states);
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err_memgpio:
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kfree(drvdata->gpios);
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err_name:
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kfree(drvdata->desc.name);
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err:
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kfree(drvdata);
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return ret;
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}
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static int __devexit gpio_regulator_remove(struct platform_device *pdev)
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{
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struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
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regulator_unregister(drvdata->dev);
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gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
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kfree(drvdata->states);
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kfree(drvdata->gpios);
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if (gpio_is_valid(drvdata->enable_gpio))
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gpio_free(drvdata->enable_gpio);
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kfree(drvdata->desc.name);
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kfree(drvdata);
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return 0;
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}
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static struct platform_driver gpio_regulator_driver = {
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.probe = gpio_regulator_probe,
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.remove = __devexit_p(gpio_regulator_remove),
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.driver = {
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.name = "gpio-regulator",
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.owner = THIS_MODULE,
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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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