diff options
Diffstat (limited to 'drivers/power/reset/sc27xx-poweroff.c')
-rw-r--r-- | drivers/power/reset/sc27xx-poweroff.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/power/reset/sc27xx-poweroff.c b/drivers/power/reset/sc27xx-poweroff.c new file mode 100644 index 0000000..65c477e --- /dev/null +++ b/drivers/power/reset/sc27xx-poweroff.c @@ -0,0 +1,66 @@ +// 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/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) + +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. + */ +void sc27xx_poweroff_shutdown(void) +{ +#ifdef CONFIG_PM_SLEEP_SMP + int cpu = smp_processor_id(); + + freeze_secondary_cpus(cpu); +#endif +} + +static struct syscore_ops poweroff_syscore_ops = { + .shutdown = sc27xx_poweroff_shutdown, +}; + +static void sc27xx_poweroff_do_poweroff(void) +{ + 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", + }, +}; +builtin_platform_driver(sc27xx_poweroff_driver); |