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