![Laxman Dewangan](/assets/img/avatar_default.png)
Adding flag on fixed regulator board configuration structure to specify whether gpio is open drain type or not. Passing this information to gpio library when requesting gpio so that gpio driver can set the pin state accordingly, for open drain type: - Pin can be set HIGH as setting as input, PULL UP on pin make this as HIGH. - Pin can be set LOW as setting it as output and drive to LOW. The non-open drain pin can be set HIGH/LOW by setting it to output and driving it to HIGH/LOW. Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
323 lines
8.2 KiB
C
323 lines
8.2 KiB
C
/*
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* 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/fixed.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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#include <linux/of.h>
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#include <linux/of_gpio.h>
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#include <linux/regulator/of_regulator.h>
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#include <linux/regulator/machine.h>
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struct fixed_voltage_data {
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struct regulator_desc desc;
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struct regulator_dev *dev;
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int microvolts;
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int gpio;
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unsigned startup_delay;
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bool enable_high;
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bool is_enabled;
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};
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/**
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* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
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* @dev: device requesting for fixed_voltage_config
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*
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* Populates fixed_voltage_config structure by extracting data from device
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* tree node, returns a pointer to the populated structure of NULL if memory
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* alloc fails.
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*/
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static struct fixed_voltage_config *
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of_get_fixed_voltage_config(struct device *dev)
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{
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struct fixed_voltage_config *config;
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struct device_node *np = dev->of_node;
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const __be32 *delay;
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struct regulator_init_data *init_data;
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config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
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GFP_KERNEL);
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if (!config)
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return NULL;
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config->init_data = of_get_regulator_init_data(dev, dev->of_node);
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if (!config->init_data)
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return NULL;
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init_data = config->init_data;
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init_data->constraints.apply_uV = 0;
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config->supply_name = init_data->constraints.name;
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if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
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config->microvolts = init_data->constraints.min_uV;
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} else {
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dev_err(dev,
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"Fixed regulator specified with variable voltages\n");
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return NULL;
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}
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if (init_data->constraints.boot_on)
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config->enabled_at_boot = true;
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config->gpio = of_get_named_gpio(np, "gpio", 0);
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delay = of_get_property(np, "startup-delay-us", NULL);
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if (delay)
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config->startup_delay = be32_to_cpu(*delay);
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if (of_find_property(np, "enable-active-high", NULL))
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config->enable_high = true;
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return config;
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}
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static int fixed_voltage_is_enabled(struct regulator_dev *dev)
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{
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struct fixed_voltage_data *data = rdev_get_drvdata(dev);
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return data->is_enabled;
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}
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static int fixed_voltage_enable(struct regulator_dev *dev)
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{
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struct fixed_voltage_data *data = rdev_get_drvdata(dev);
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gpio_set_value_cansleep(data->gpio, data->enable_high);
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data->is_enabled = true;
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return 0;
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}
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static int fixed_voltage_disable(struct regulator_dev *dev)
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{
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struct fixed_voltage_data *data = rdev_get_drvdata(dev);
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gpio_set_value_cansleep(data->gpio, !data->enable_high);
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data->is_enabled = false;
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return 0;
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}
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static int fixed_voltage_enable_time(struct regulator_dev *dev)
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{
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struct fixed_voltage_data *data = rdev_get_drvdata(dev);
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return data->startup_delay;
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}
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static int fixed_voltage_get_voltage(struct regulator_dev *dev)
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{
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struct fixed_voltage_data *data = rdev_get_drvdata(dev);
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if (data->microvolts)
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return data->microvolts;
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else
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return -EINVAL;
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}
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static int fixed_voltage_list_voltage(struct regulator_dev *dev,
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unsigned selector)
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{
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struct fixed_voltage_data *data = rdev_get_drvdata(dev);
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if (selector != 0)
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return -EINVAL;
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return data->microvolts;
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}
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static struct regulator_ops fixed_voltage_gpio_ops = {
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.is_enabled = fixed_voltage_is_enabled,
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.enable = fixed_voltage_enable,
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.disable = fixed_voltage_disable,
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.enable_time = fixed_voltage_enable_time,
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.get_voltage = fixed_voltage_get_voltage,
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.list_voltage = fixed_voltage_list_voltage,
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};
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static struct regulator_ops fixed_voltage_ops = {
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.get_voltage = fixed_voltage_get_voltage,
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.list_voltage = fixed_voltage_list_voltage,
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};
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static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
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{
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struct fixed_voltage_config *config;
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struct fixed_voltage_data *drvdata;
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int ret;
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if (pdev->dev.of_node)
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config = of_get_fixed_voltage_config(&pdev->dev);
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else
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config = pdev->dev.platform_data;
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if (!config)
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return -ENOMEM;
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drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
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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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ret = -ENOMEM;
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goto err;
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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->desc.type = REGULATOR_VOLTAGE;
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drvdata->desc.owner = THIS_MODULE;
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if (config->microvolts)
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drvdata->desc.n_voltages = 1;
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drvdata->microvolts = config->microvolts;
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drvdata->gpio = config->gpio;
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drvdata->startup_delay = config->startup_delay;
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if (gpio_is_valid(config->gpio)) {
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int gpio_flag;
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drvdata->enable_high = config->enable_high;
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/* FIXME: Remove below print warning
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*
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* config->gpio must be set to -EINVAL by platform code if
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* GPIO control is not required. However, early adopters
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* not requiring GPIO control may forget to initialize
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* config->gpio to -EINVAL. This will cause GPIO 0 to be used
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* for GPIO control.
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*
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* This warning will be removed once there are a couple of users
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* for this driver.
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*/
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if (!config->gpio)
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dev_warn(&pdev->dev,
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"using GPIO 0 for regulator enable control\n");
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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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drvdata->is_enabled = config->enabled_at_boot;
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ret = drvdata->is_enabled ?
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config->enable_high : !config->enable_high;
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gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
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if (config->gpio_is_open_drain)
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gpio_flag |= GPIOF_OPEN_DRAIN;
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ret = gpio_request_one(config->gpio, gpio_flag,
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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->gpio, ret);
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goto err_name;
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}
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drvdata->desc.ops = &fixed_voltage_gpio_ops;
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} else {
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drvdata->desc.ops = &fixed_voltage_ops;
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}
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drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
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config->init_data, drvdata,
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pdev->dev.of_node);
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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_gpio;
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}
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platform_set_drvdata(pdev, drvdata);
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dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
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drvdata->microvolts);
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return 0;
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err_gpio:
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if (gpio_is_valid(config->gpio))
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gpio_free(config->gpio);
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err_name:
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kfree(drvdata->desc.name);
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err:
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return ret;
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}
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static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
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{
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struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
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regulator_unregister(drvdata->dev);
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if (gpio_is_valid(drvdata->gpio))
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gpio_free(drvdata->gpio);
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kfree(drvdata->desc.name);
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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 fixed_of_match[] __devinitconst = {
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{ .compatible = "regulator-fixed", },
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{},
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};
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MODULE_DEVICE_TABLE(of, fixed_of_match);
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#else
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#define fixed_of_match NULL
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#endif
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static struct platform_driver regulator_fixed_voltage_driver = {
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.probe = reg_fixed_voltage_probe,
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.remove = __devexit_p(reg_fixed_voltage_remove),
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.driver = {
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.name = "reg-fixed-voltage",
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.owner = THIS_MODULE,
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.of_match_table = fixed_of_match,
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},
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};
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static int __init regulator_fixed_voltage_init(void)
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{
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return platform_driver_register(®ulator_fixed_voltage_driver);
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}
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subsys_initcall(regulator_fixed_voltage_init);
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static void __exit regulator_fixed_voltage_exit(void)
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{
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platform_driver_unregister(®ulator_fixed_voltage_driver);
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}
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module_exit(regulator_fixed_voltage_exit);
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MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
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MODULE_DESCRIPTION("Fixed voltage regulator");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:reg-fixed-voltage");
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