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/drivers/regulator/userspace-consumer.c

http://github.com/mirrors/linux
C | 181 lines | 129 code | 36 blank | 16 comment | 21 complexity | 933ddb5fa72f26a4cc170d0c924192c2 MD5 | raw file
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * userspace-consumer.c
  4 *
  5 * Copyright 2009 CompuLab, Ltd.
  6 *
  7 * Author: Mike Rapoport <mike@compulab.co.il>
  8 *
  9 * Based of virtual consumer driver:
 10 *   Copyright 2008 Wolfson Microelectronics PLC.
 11 *   Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 12 */
 13
 14#include <linux/err.h>
 15#include <linux/mutex.h>
 16#include <linux/module.h>
 17#include <linux/platform_device.h>
 18#include <linux/regulator/consumer.h>
 19#include <linux/regulator/userspace-consumer.h>
 20#include <linux/slab.h>
 21
 22struct userspace_consumer_data {
 23	const char *name;
 24
 25	struct mutex lock;
 26	bool enabled;
 27
 28	int num_supplies;
 29	struct regulator_bulk_data *supplies;
 30};
 31
 32static ssize_t reg_show_name(struct device *dev,
 33			  struct device_attribute *attr, char *buf)
 34{
 35	struct userspace_consumer_data *data = dev_get_drvdata(dev);
 36
 37	return sprintf(buf, "%s\n", data->name);
 38}
 39
 40static ssize_t reg_show_state(struct device *dev,
 41			  struct device_attribute *attr, char *buf)
 42{
 43	struct userspace_consumer_data *data = dev_get_drvdata(dev);
 44
 45	if (data->enabled)
 46		return sprintf(buf, "enabled\n");
 47
 48	return sprintf(buf, "disabled\n");
 49}
 50
 51static ssize_t reg_set_state(struct device *dev, struct device_attribute *attr,
 52			 const char *buf, size_t count)
 53{
 54	struct userspace_consumer_data *data = dev_get_drvdata(dev);
 55	bool enabled;
 56	int ret;
 57
 58	/*
 59	 * sysfs_streq() doesn't need the \n's, but we add them so the strings
 60	 * will be shared with show_state(), above.
 61	 */
 62	if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
 63		enabled = true;
 64	else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
 65		enabled = false;
 66	else {
 67		dev_err(dev, "Configuring invalid mode\n");
 68		return count;
 69	}
 70
 71	mutex_lock(&data->lock);
 72	if (enabled != data->enabled) {
 73		if (enabled)
 74			ret = regulator_bulk_enable(data->num_supplies,
 75						    data->supplies);
 76		else
 77			ret = regulator_bulk_disable(data->num_supplies,
 78						     data->supplies);
 79
 80		if (ret == 0)
 81			data->enabled = enabled;
 82		else
 83			dev_err(dev, "Failed to configure state: %d\n", ret);
 84	}
 85	mutex_unlock(&data->lock);
 86
 87	return count;
 88}
 89
 90static DEVICE_ATTR(name, 0444, reg_show_name, NULL);
 91static DEVICE_ATTR(state, 0644, reg_show_state, reg_set_state);
 92
 93static struct attribute *attributes[] = {
 94	&dev_attr_name.attr,
 95	&dev_attr_state.attr,
 96	NULL,
 97};
 98
 99static const struct attribute_group attr_group = {
100	.attrs	= attributes,
101};
102
103static int regulator_userspace_consumer_probe(struct platform_device *pdev)
104{
105	struct regulator_userspace_consumer_data *pdata;
106	struct userspace_consumer_data *drvdata;
107	int ret;
108
109	pdata = dev_get_platdata(&pdev->dev);
110	if (!pdata)
111		return -EINVAL;
112
113	drvdata = devm_kzalloc(&pdev->dev,
114			       sizeof(struct userspace_consumer_data),
115			       GFP_KERNEL);
116	if (drvdata == NULL)
117		return -ENOMEM;
118
119	drvdata->name = pdata->name;
120	drvdata->num_supplies = pdata->num_supplies;
121	drvdata->supplies = pdata->supplies;
122
123	mutex_init(&drvdata->lock);
124
125	ret = devm_regulator_bulk_get(&pdev->dev, drvdata->num_supplies,
126				      drvdata->supplies);
127	if (ret) {
128		dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
129		return ret;
130	}
131
132	ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
133	if (ret != 0)
134		return ret;
135
136	if (pdata->init_on) {
137		ret = regulator_bulk_enable(drvdata->num_supplies,
138					    drvdata->supplies);
139		if (ret) {
140			dev_err(&pdev->dev,
141				"Failed to set initial state: %d\n", ret);
142			goto err_enable;
143		}
144	}
145
146	drvdata->enabled = pdata->init_on;
147	platform_set_drvdata(pdev, drvdata);
148
149	return 0;
150
151err_enable:
152	sysfs_remove_group(&pdev->dev.kobj, &attr_group);
153
154	return ret;
155}
156
157static int regulator_userspace_consumer_remove(struct platform_device *pdev)
158{
159	struct userspace_consumer_data *data = platform_get_drvdata(pdev);
160
161	sysfs_remove_group(&pdev->dev.kobj, &attr_group);
162
163	if (data->enabled)
164		regulator_bulk_disable(data->num_supplies, data->supplies);
165
166	return 0;
167}
168
169static struct platform_driver regulator_userspace_consumer_driver = {
170	.probe		= regulator_userspace_consumer_probe,
171	.remove		= regulator_userspace_consumer_remove,
172	.driver		= {
173		.name		= "reg-userspace-consumer",
174	},
175};
176
177module_platform_driver(regulator_userspace_consumer_driver);
178
179MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
180MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
181MODULE_LICENSE("GPL");