// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2018 Spreadtrum Communications Inc.
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* Copyright (C) 2018 Linaro Ltd.
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*/
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#include <linux/cpu.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/regmap.h>
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#include <linux/syscore_ops.h>
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#define SC27XX_PWR_PD_HW 0xc2c
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#define SC27XX_PWR_OFF_EN BIT(0)
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#define SC27XX_SLP_CTRL 0xdf0
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#define SC27XX_LDO_XTL_EN BIT(3)
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static struct regmap *regmap;
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/*
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* On Spreadtrum platform, we need power off system through external SC27xx
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* series PMICs, and it is one similar SPI bus mapped by regmap to access PMIC,
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* which is not fast io access.
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*
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* So before stopping other cores, we need release other cores' resource by
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* taking cpus down to avoid racing regmap or spi mutex lock when poweroff
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* system through PMIC.
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*/
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static void sc27xx_poweroff_shutdown(void)
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{
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#ifdef CONFIG_HOTPLUG_CPU
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int cpu;
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for_each_online_cpu(cpu) {
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if (cpu != smp_processor_id())
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remove_cpu(cpu);
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}
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#endif
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}
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static struct syscore_ops poweroff_syscore_ops = {
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.shutdown = sc27xx_poweroff_shutdown,
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};
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static void sc27xx_poweroff_do_poweroff(void)
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{
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/* Disable the external subsys connection's power firstly */
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regmap_write(regmap, SC27XX_SLP_CTRL, SC27XX_LDO_XTL_EN);
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regmap_write(regmap, SC27XX_PWR_PD_HW, SC27XX_PWR_OFF_EN);
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}
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static int sc27xx_poweroff_probe(struct platform_device *pdev)
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{
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if (regmap)
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return -EINVAL;
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regmap = dev_get_regmap(pdev->dev.parent, NULL);
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if (!regmap)
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return -ENODEV;
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pm_power_off = sc27xx_poweroff_do_poweroff;
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register_syscore_ops(&poweroff_syscore_ops);
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return 0;
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}
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static struct platform_driver sc27xx_poweroff_driver = {
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.probe = sc27xx_poweroff_probe,
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.driver = {
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.name = "sc27xx-poweroff",
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},
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};
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module_platform_driver(sc27xx_poweroff_driver);
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MODULE_DESCRIPTION("Power off driver for SC27XX PMIC Device");
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MODULE_AUTHOR("Baolin Wang <baolin.wang@unisoc.com>");
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MODULE_LICENSE("GPL v2");
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