blob: b833c4e1fa697deb958581df5c584d809f992481 [file] [log] [blame]
/*
* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/proxy-consumer.h>
struct proxy_consumer {
struct list_head list;
struct regulator *reg;
bool enable;
int min_uV;
int max_uV;
u32 current_uA;
};
static DEFINE_MUTEX(proxy_consumer_list_mutex);
static LIST_HEAD(proxy_consumer_list);
static bool proxy_consumers_removed;
/**
* regulator_proxy_consumer_register() - conditionally register a proxy consumer
* for the specified regulator and set its boot time parameters
* @reg_dev: Device pointer of the regulator
* @reg_node: Device node pointer of the regulator
*
* Returns a struct proxy_consumer pointer corresponding to the regulator on
* success, ERR_PTR() if an error occurred, or NULL if no proxy consumer is
* needed for the regulator. This function calls
* regulator_get(reg_dev, "proxy") after first checking if any proxy consumer
* properties are present in the reg_node device node. After that, the voltage,
* minimum current, and/or the enable state will be set based upon the device
* node property values.
*/
struct proxy_consumer *regulator_proxy_consumer_register(struct device *reg_dev,
struct device_node *reg_node)
{
struct proxy_consumer *consumer = NULL;
const char *reg_name = "";
u32 voltage[2] = {0};
int rc;
/* Return immediately if no proxy consumer properties are specified. */
if (!of_find_property(reg_node, "qcom,proxy-consumer-enable", NULL)
&& !of_find_property(reg_node, "qcom,proxy-consumer-voltage", NULL)
&& !of_find_property(reg_node, "qcom,proxy-consumer-current", NULL))
return NULL;
mutex_lock(&proxy_consumer_list_mutex);
/* Do not register new consumers if they cannot be removed later. */
if (proxy_consumers_removed) {
rc = -EPERM;
goto unlock;
}
if (dev_name(reg_dev))
reg_name = dev_name(reg_dev);
consumer = kzalloc(sizeof(*consumer), GFP_KERNEL);
if (!consumer) {
pr_err("kzalloc failed\n");
rc = -ENOMEM;
goto unlock;
}
consumer->enable
= of_property_read_bool(reg_node, "qcom,proxy-consumer-enable");
of_property_read_u32(reg_node, "qcom,proxy-consumer-current",
&consumer->current_uA);
rc = of_property_read_u32_array(reg_node, "qcom,proxy-consumer-voltage",
voltage, 2);
if (!rc) {
consumer->min_uV = voltage[0];
consumer->max_uV = voltage[1];
}
dev_dbg(reg_dev, "proxy consumer request: enable=%d, voltage_range=[%d, %d] uV, min_current=%d uA\n",
consumer->enable, consumer->min_uV, consumer->max_uV,
consumer->current_uA);
consumer->reg = regulator_get(reg_dev, "proxy");
if (IS_ERR_OR_NULL(consumer->reg)) {
rc = PTR_ERR(consumer->reg);
pr_err("regulator_get() failed for %s, rc=%d\n", reg_name, rc);
goto unlock;
}
if (consumer->max_uV > 0 && consumer->min_uV <= consumer->max_uV) {
rc = regulator_set_voltage(consumer->reg, consumer->min_uV,
consumer->max_uV);
if (rc) {
pr_err("regulator_set_voltage %s failed, rc=%d\n",
reg_name, rc);
goto free_regulator;
}
}
if (consumer->current_uA > 0) {
rc = regulator_set_optimum_mode(consumer->reg,
consumer->current_uA);
if (rc < 0) {
pr_err("regulator_set_optimum_mode %s failed, rc=%d\n",
reg_name, rc);
goto remove_voltage;
}
}
if (consumer->enable) {
rc = regulator_enable(consumer->reg);
if (rc) {
pr_err("regulator_enable %s failed, rc=%d\n", reg_name,
rc);
goto remove_current;
}
}
list_add(&consumer->list, &proxy_consumer_list);
mutex_unlock(&proxy_consumer_list_mutex);
return consumer;
remove_current:
regulator_set_optimum_mode(consumer->reg, 0);
remove_voltage:
regulator_set_voltage(consumer->reg, 0, INT_MAX);
free_regulator:
regulator_put(consumer->reg);
unlock:
kfree(consumer);
mutex_unlock(&proxy_consumer_list_mutex);
return ERR_PTR(rc);
}
/* proxy_consumer_list_mutex must be held by caller. */
static int regulator_proxy_consumer_remove(struct proxy_consumer *consumer)
{
int rc = 0;
if (consumer->enable) {
rc = regulator_disable(consumer->reg);
if (rc)
pr_err("regulator_disable failed, rc=%d\n", rc);
}
if (consumer->current_uA > 0) {
rc = regulator_set_optimum_mode(consumer->reg, 0);
if (rc < 0)
pr_err("regulator_set_optimum_mode failed, rc=%d\n",
rc);
}
if (consumer->max_uV > 0 && consumer->min_uV <= consumer->max_uV) {
rc = regulator_set_voltage(consumer->reg, 0, INT_MAX);
if (rc)
pr_err("regulator_set_voltage failed, rc=%d\n", rc);
}
regulator_put(consumer->reg);
list_del(&consumer->list);
kfree(consumer);
return rc;
}
/**
* regulator_proxy_consumer_unregister() - unregister a proxy consumer and
* remove its boot time requests
* @consumer: Pointer to proxy_consumer to be removed
*
* Returns 0 on success or errno on failure. This function removes all requests
* made by the proxy consumer in regulator_proxy_consumer_register() and then
* frees the consumer's resources.
*/
int regulator_proxy_consumer_unregister(struct proxy_consumer *consumer)
{
int rc = 0;
if (IS_ERR_OR_NULL(consumer))
return 0;
mutex_lock(&proxy_consumer_list_mutex);
if (!proxy_consumers_removed)
rc = regulator_proxy_consumer_remove(consumer);
mutex_unlock(&proxy_consumer_list_mutex);
return rc;
}
/*
* Remove all proxy requests at late_initcall_sync. The assumption is that all
* devices have probed at this point and made their own regulator requests.
*/
static int __init regulator_proxy_consumer_remove_all(void)
{
struct proxy_consumer *consumer;
struct proxy_consumer *temp;
mutex_lock(&proxy_consumer_list_mutex);
proxy_consumers_removed = true;
if (!list_empty(&proxy_consumer_list))
pr_info("removing regulator proxy consumer requests\n");
list_for_each_entry_safe(consumer, temp, &proxy_consumer_list, list) {
regulator_proxy_consumer_remove(consumer);
}
mutex_unlock(&proxy_consumer_list_mutex);
return 0;
}
late_initcall_sync(regulator_proxy_consumer_remove_all);