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1// SPDX-License-Identifier: GPL-2.02/*3 * Power off through MediaTek PMIC4 *5 * Copyright (C) 2018 MediaTek Inc.6 *7 * Author: Sean Wang <sean.wang@mediatek.com>8 *9 */10 11#include <linux/err.h>12#include <linux/module.h>13#include <linux/of.h>14#include <linux/platform_device.h>15#include <linux/mfd/mt6397/core.h>16#include <linux/mfd/mt6397/rtc.h>17#include <linux/reboot.h>18 19struct mt6323_pwrc {20 struct device *dev;21 struct regmap *regmap;22 u32 base;23};24 25static int mt6323_do_pwroff(struct sys_off_data *data)26{27 struct mt6323_pwrc *pwrc = data->cb_data;28 unsigned int val;29 int ret;30 31 regmap_write(pwrc->regmap, pwrc->base + RTC_BBPU, RTC_BBPU_KEY);32 regmap_write(pwrc->regmap, pwrc->base + RTC_WRTGR_MT6323, 1);33 34 ret = regmap_read_poll_timeout(pwrc->regmap,35 pwrc->base + RTC_BBPU, val,36 !(val & RTC_BBPU_CBUSY),37 MTK_RTC_POLL_DELAY_US,38 MTK_RTC_POLL_TIMEOUT);39 if (ret)40 dev_err(pwrc->dev, "failed to write BBPU: %d\n", ret);41 42 /* Wait some time until system down, otherwise, notice with a warn */43 mdelay(1000);44 45 WARN_ONCE(1, "Unable to power off system\n");46 47 return NOTIFY_DONE;48}49 50static int mt6323_pwrc_probe(struct platform_device *pdev)51{52 struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);53 struct mt6323_pwrc *pwrc;54 struct resource *res;55 int ret;56 57 pwrc = devm_kzalloc(&pdev->dev, sizeof(*pwrc), GFP_KERNEL);58 if (!pwrc)59 return -ENOMEM;60 61 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);62 if (!res)63 return -EINVAL;64 65 pwrc->base = res->start;66 pwrc->regmap = mt6397_chip->regmap;67 pwrc->dev = &pdev->dev;68 69 ret = devm_register_sys_off_handler(pwrc->dev,70 SYS_OFF_MODE_POWER_OFF,71 SYS_OFF_PRIO_DEFAULT,72 mt6323_do_pwroff,73 pwrc);74 if (ret)75 return dev_err_probe(pwrc->dev, ret, "failed to register power-off handler\n");76 77 return 0;78}79 80static const struct of_device_id mt6323_pwrc_dt_match[] = {81 { .compatible = "mediatek,mt6323-pwrc" },82 {},83};84MODULE_DEVICE_TABLE(of, mt6323_pwrc_dt_match);85 86static struct platform_driver mt6323_pwrc_driver = {87 .probe = mt6323_pwrc_probe,88 .driver = {89 .name = "mt6323-pwrc",90 .of_match_table = mt6323_pwrc_dt_match,91 },92};93 94module_platform_driver(mt6323_pwrc_driver);95 96MODULE_DESCRIPTION("Poweroff driver for MT6323 PMIC");97MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");98