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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (C) 2018 Spreadtrum Communications Inc.4 * Copyright (C) 2018 Linaro Ltd.5 */6 7#include <linux/cpu.h>8#include <linux/kernel.h>9#include <linux/module.h>10#include <linux/platform_device.h>11#include <linux/pm.h>12#include <linux/regmap.h>13#include <linux/syscore_ops.h>14 15#define SC27XX_PWR_PD_HW 0xc2c16#define SC27XX_PWR_OFF_EN BIT(0)17#define SC27XX_SLP_CTRL 0xdf018#define SC27XX_LDO_XTL_EN BIT(3)19 20static struct regmap *regmap;21 22/*23 * On Spreadtrum platform, we need power off system through external SC27xx24 * series PMICs, and it is one similar SPI bus mapped by regmap to access PMIC,25 * which is not fast io access.26 *27 * So before stopping other cores, we need release other cores' resource by28 * taking cpus down to avoid racing regmap or spi mutex lock when poweroff29 * system through PMIC.30 */31static void sc27xx_poweroff_shutdown(void)32{33#ifdef CONFIG_HOTPLUG_CPU34 int cpu;35 36 for_each_online_cpu(cpu) {37 if (cpu != smp_processor_id())38 remove_cpu(cpu);39 }40#endif41}42 43static struct syscore_ops poweroff_syscore_ops = {44 .shutdown = sc27xx_poweroff_shutdown,45};46 47static void sc27xx_poweroff_do_poweroff(void)48{49 /* Disable the external subsys connection's power firstly */50 regmap_write(regmap, SC27XX_SLP_CTRL, SC27XX_LDO_XTL_EN);51 52 regmap_write(regmap, SC27XX_PWR_PD_HW, SC27XX_PWR_OFF_EN);53}54 55static int sc27xx_poweroff_probe(struct platform_device *pdev)56{57 if (regmap)58 return -EINVAL;59 60 regmap = dev_get_regmap(pdev->dev.parent, NULL);61 if (!regmap)62 return -ENODEV;63 64 pm_power_off = sc27xx_poweroff_do_poweroff;65 register_syscore_ops(&poweroff_syscore_ops);66 return 0;67}68 69static struct platform_driver sc27xx_poweroff_driver = {70 .probe = sc27xx_poweroff_probe,71 .driver = {72 .name = "sc27xx-poweroff",73 },74};75module_platform_driver(sc27xx_poweroff_driver);76 77MODULE_DESCRIPTION("Power off driver for SC27XX PMIC Device");78MODULE_AUTHOR("Baolin Wang <baolin.wang@unisoc.com>");79MODULE_LICENSE("GPL v2");80