android_kernel_samsung_hero.../drivers/cpuidle/lpm-workarounds.c
2016-08-17 16:41:52 +08:00

134 lines
3.2 KiB
C

/* Copyright (c) 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.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/rpm-smd-regulator.h>
static struct regulator *lpm_cx_reg;
static struct work_struct dummy_vote_work;
static struct workqueue_struct *lpm_wa_wq;
static bool lpm_wa_cx_turbo_unvote;
/* While exiting from RPM assisted power collapse on some targets like MSM8939
* the CX is bumped to turbo mode by RPM. To reduce the power impact, APSS
* low power driver need to remove the CX turbo vote.
*/
static void send_dummy_cx_vote(struct work_struct *w)
{
if (lpm_cx_reg) {
regulator_set_voltage(lpm_cx_reg,
RPM_REGULATOR_CORNER_SUPER_TURBO,
RPM_REGULATOR_CORNER_SUPER_TURBO);
regulator_set_voltage(lpm_cx_reg,
RPM_REGULATOR_CORNER_NONE,
RPM_REGULATOR_CORNER_SUPER_TURBO);
}
}
/*
* lpm_wa_cx_unvote_send(): Unvote for CX turbo mode
*/
void lpm_wa_cx_unvote_send(void)
{
if (lpm_wa_cx_turbo_unvote)
queue_work(lpm_wa_wq, &dummy_vote_work);
}
EXPORT_SYMBOL(lpm_wa_cx_unvote_send);
static int lpm_wa_cx_unvote_init(struct platform_device *pdev)
{
int ret = 0;
lpm_cx_reg = devm_regulator_get(&pdev->dev, "lpm-cx");
if (IS_ERR(lpm_cx_reg)) {
ret = PTR_ERR(lpm_cx_reg);
if (ret != -EPROBE_DEFER)
pr_err("Unable to get the CX regulator\n");
return ret;
}
INIT_WORK(&dummy_vote_work, send_dummy_cx_vote);
lpm_wa_wq = alloc_workqueue("lpm-wa",
WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_HIGHPRI, 1);
return ret;
}
static int lpm_wa_cx_unvote_exit(void)
{
if (lpm_wa_wq)
destroy_workqueue(lpm_wa_wq);
return 0;
}
static int lpm_wa_probe(struct platform_device *pdev)
{
int ret = 0;
lpm_wa_cx_turbo_unvote = of_property_read_bool(pdev->dev.of_node,
"qcom,lpm-wa-cx-turbo-unvote");
if (lpm_wa_cx_turbo_unvote) {
ret = lpm_wa_cx_unvote_init(pdev);
if (ret) {
pr_err("%s: Failed to initialize lpm_wa_cx_unvote (%d)\n",
__func__, ret);
return ret;
}
}
return ret;
}
static int lpm_wa_remove(struct platform_device *pdev)
{
int ret = 0;
if (lpm_wa_cx_turbo_unvote)
ret = lpm_wa_cx_unvote_exit();
return ret;
}
static struct of_device_id lpm_wa_mtch_tbl[] = {
{.compatible = "qcom,lpm-workarounds"},
{},
};
static struct platform_driver lpm_wa_driver = {
.probe = lpm_wa_probe,
.remove = lpm_wa_remove,
.driver = {
.name = "lpm-workarounds",
.owner = THIS_MODULE,
.of_match_table = lpm_wa_mtch_tbl,
},
};
static int __init lpm_wa_module_init(void)
{
int ret;
ret = platform_driver_register(&lpm_wa_driver);
if (ret)
pr_info("Error registering %s\n", lpm_wa_driver.driver.name);
return ret;
}
late_initcall(lpm_wa_module_init);