Messages in this thread | | | From | Baolin Wang <> | Date | Fri, 9 Feb 2018 14:25:40 +0800 | Subject | Re: [PATCH] power: reset: Add Spreadtrum SC27xx PMIC power off support |
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Hi Sebastian,
On 9 February 2018 at 05:50, Sebastian Reichel <sre@kernel.org> wrote: > Hi Baolin, > > On Mon, Jan 15, 2018 at 03:58:57PM +0800, Baolin Wang wrote: >> On Spreadtrum platform, we need power off system through external SC27xx >> series PMICs including the SC2720, SC2721, SC2723, SC2730 and SC2731 chips. >> Thus this patch adds SC27xx series PMICs power-off support. >> >> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> >> --- >> drivers/power/reset/Kconfig | 9 +++++ >> drivers/power/reset/Makefile | 1 + >> drivers/power/reset/sc27xx-poweroff.c | 65 +++++++++++++++++++++++++++++++++ >> 3 files changed, 75 insertions(+) >> create mode 100644 drivers/power/reset/sc27xx-poweroff.c >> >> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig >> index ca0de1a..611ae56 100644 >> --- a/drivers/power/reset/Kconfig >> +++ b/drivers/power/reset/Kconfig >> @@ -227,5 +227,14 @@ config SYSCON_REBOOT_MODE >> register, then the bootloader can read it to take different >> action according to the mode. >> >> +config POWER_RESET_SC27XX >> + tristate "Spreadtrum SC27xx PMIC power-off driver" >> + depends on MFD_SC27XX_PMIC || COMPILE_TEST >> + help >> + This driver supports powering off a system through >> + Spreadtrum SC27xx series PMICs. The SC27xx series >> + PMICs includes the SC2720, SC2721, SC2723, SC2730 >> + and SC2731 chips. >> + >> endif >> >> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile >> index aeb65ed..225d645 100644 >> --- a/drivers/power/reset/Makefile >> +++ b/drivers/power/reset/Makefile >> @@ -27,3 +27,4 @@ obj-$(CONFIG_POWER_RESET_RMOBILE) += rmobile-reset.o >> obj-$(CONFIG_POWER_RESET_ZX) += zx-reboot.o >> obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o >> obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o >> +obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o >> diff --git a/drivers/power/reset/sc27xx-poweroff.c b/drivers/power/reset/sc27xx-poweroff.c >> new file mode 100644 >> index 0000000..8e4b6a0 >> --- /dev/null >> +++ b/drivers/power/reset/sc27xx-poweroff.c >> @@ -0,0 +1,65 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2017 Spreadtrum Communications Inc. >> + * Copyright (c) 2017 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) >> + >> +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) >> +{ >> + int cpu = smp_processor_id(); >> + >> + freeze_secondary_cpus(cpu); >> +} >> + >> +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;
OK.
> >> + 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 void sc27xx_poweroff_remove(struct platform_device *pdev) { > if (pm_power_off == sc27xx_poweroff_do_poweroff) > pm_power_off = NULL; > regmap = NULL; > }
OK. I will add it in next version.
> >> +static struct platform_driver sc27xx_poweroff_driver = { >> + .probe = sc27xx_poweroff_probe, > > .remove = sc27xx_poweroff_remove, > >> + .driver = { >> + .name = "sc27xx-poweroff", >> + }, >> +}; >> +module_platform_driver(sc27xx_poweroff_driver); >> + >> +MODULE_DESCRIPTION("Spreadtrum SC27xx PMIC Poweroff Driver"); >> +MODULE_LICENSE("GPL v2"); > > MODULE_ALIAS("platform:sc27xx-poweroff");
OK. Thanks for your comments.
-- Baolin.wang Best Regards
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