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/*
* Copyright (c) 2015-2016, 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.
*/
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/async.h>
#include <linux/clk/gdsc.h>
#include <linux/regulator/consumer.h>
#include <soc/qcom/subsystem_notif.h>
struct subsystem {
const char *name;
void *notif_handle;
struct notifier_block nb;
bool booted;
struct inrush_driver_data *drv_data;
};
struct inrush_driver_data {
int subsys_count;
int subsys_boot_count;
struct regulator *vreg;
/* Must be the last member */
struct subsystem *subsystems;
};
#define notifier_to_subsystem(d) container_of(d, struct subsystem, nb)
static void free_resources(void *data, async_cookie_t cookie)
{
struct inrush_driver_data *drv_data = data;
struct subsystem *subsys;
int i;
gdsc_allow_clear_retention(drv_data->vreg);
devm_regulator_put(drv_data->vreg);
for (i = 0; i < drv_data->subsys_count; i++) {
subsys = &drv_data->subsystems[i];
subsys_notif_unregister_notifier(subsys->notif_handle,
&subsys->nb);
}
kfree(drv_data);
pr_info("inrush-current-mitigation driver exited\n");
}
static int mitigate_inrush_notifier_cb(struct notifier_block *nb,
unsigned long code, void *ss_handle)
{
struct subsystem *subsys = notifier_to_subsystem(nb);
struct inrush_driver_data *drv_data = subsys->drv_data;
if (subsys->booted)
return NOTIFY_DONE;
switch (code) {
case SUBSYS_AFTER_POWERUP:
pr_info("%s: subsystem %s has completed powerup\n", __func__,
subsys->name);
subsys->booted = true;
drv_data->subsys_boot_count++;
break;
default:
return NOTIFY_DONE;
}
/*
* If all subsystems are up, job of this driver ends, lets
* free resources.
*/
if (drv_data->subsys_count == drv_data->subsys_boot_count)
async_schedule(free_resources, drv_data);
return NOTIFY_DONE;
}
static int mitigate_inrush_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
int i, retval;
struct subsystem *subsys;
struct inrush_driver_data *drv_data;
retval = of_property_count_strings(np,
"qcom,dependent-subsystems");
if (IS_ERR_VALUE(retval)) {
dev_err(dev, "Failed to get dependent subsystems\n");
return -EINVAL;
}
drv_data = kzalloc((retval * sizeof(struct subsystem) +
sizeof(struct inrush_driver_data)), GFP_KERNEL);
if (!drv_data)
return -ENOMEM;
drv_data->subsystems = (void *)drv_data +
sizeof(struct inrush_driver_data);
drv_data->subsys_count = retval;
for (i = 0; i < drv_data->subsys_count; i++) {
subsys = &drv_data->subsystems[i];
subsys->drv_data = drv_data;
of_property_read_string_index(np, "qcom,dependent-subsystems",
i, &subsys->name);
subsys->nb.notifier_call = mitigate_inrush_notifier_cb;
subsys->notif_handle =
subsys_notif_register_notifier(subsys->name,
&subsys->nb);
if (IS_ERR(subsys->notif_handle)) {
dev_err(dev, "Notifier registration failed for %s\n",
subsys->name);
retval = PTR_ERR(subsys->notif_handle);
goto err_subsys_notif;
}
}
drv_data->vreg = devm_regulator_get(dev, "vdd");
if (IS_ERR(drv_data->vreg)) {
dev_err(dev, "Failed to get regulator\n");
return PTR_ERR(drv_data->vreg);
}
return 0;
err_subsys_notif:
for (i = 0; i < drv_data->subsys_count; i++) {
subsys = &drv_data->subsystems[i];
subsys_notif_unregister_notifier(subsys->notif_handle,
&subsys->nb);
}
kfree(drv_data);
return retval;
}
static const struct of_device_id mitigate_inrush_match_table[] = {
{ .compatible = "qcom,msm-inrush-current-mitigation" },
{},
};
static struct platform_driver mitigate_inrush_driver = {
.probe = mitigate_inrush_probe,
.driver = {
.name = "msm-inrush-current",
.owner = THIS_MODULE,
.of_match_table = mitigate_inrush_match_table,
},
};
static int init_msm_mitigate_inrush(void)
{
return platform_driver_register(&mitigate_inrush_driver);
}
late_initcall(init_msm_mitigate_inrush);
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