linux/drivers/power/reset/mt6323-poweroff.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Power off through MediaTek PMIC
*
* Copyright (C) 2018 MediaTek Inc.
*
* Author: Sean Wang <sean.wang@mediatek.com>
*
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/mfd/mt6397/rtc.h>
struct mt6323_pwrc {
struct device *dev;
struct regmap *regmap;
u32 base;
};
static struct mt6323_pwrc *mt_pwrc;
static void mt6323_do_pwroff(void)
{
struct mt6323_pwrc *pwrc = mt_pwrc;
unsigned int val;
int ret;
regmap_write(pwrc->regmap, pwrc->base + RTC_BBPU, RTC_BBPU_KEY);
regmap_write(pwrc->regmap, pwrc->base + RTC_WRTGR, 1);
ret = regmap_read_poll_timeout(pwrc->regmap,
pwrc->base + RTC_BBPU, val,
!(val & RTC_BBPU_CBUSY),
MTK_RTC_POLL_DELAY_US,
MTK_RTC_POLL_TIMEOUT);
if (ret)
dev_err(pwrc->dev, "failed to write BBPU: %d\n", ret);
/* Wait some time until system down, otherwise, notice with a warn */
mdelay(1000);
WARN_ONCE(1, "Unable to power off system\n");
}
static int mt6323_pwrc_probe(struct platform_device *pdev)
{
struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
struct mt6323_pwrc *pwrc;
struct resource *res;
pwrc = devm_kzalloc(&pdev->dev, sizeof(*pwrc), GFP_KERNEL);
if (!pwrc)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pwrc->base = res->start;
pwrc->regmap = mt6397_chip->regmap;
pwrc->dev = &pdev->dev;
mt_pwrc = pwrc;
pm_power_off = &mt6323_do_pwroff;
return 0;
}
static int mt6323_pwrc_remove(struct platform_device *pdev)
{
if (pm_power_off == &mt6323_do_pwroff)
pm_power_off = NULL;
return 0;
}
static const struct of_device_id mt6323_pwrc_dt_match[] = {
{ .compatible = "mediatek,mt6323-pwrc" },
{},
};
MODULE_DEVICE_TABLE(of, mt6323_pwrc_dt_match);
static struct platform_driver mt6323_pwrc_driver = {
.probe = mt6323_pwrc_probe,
.remove = mt6323_pwrc_remove,
.driver = {
.name = "mt6323-pwrc",
.of_match_table = mt6323_pwrc_dt_match,
},
};
module_platform_driver(mt6323_pwrc_driver);
MODULE_DESCRIPTION("Poweroff driver for MT6323 PMIC");
MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_LICENSE("GPL v2");