Hi, On Wed, Apr 25, 2018 at 05:32:41PM +0800, sean.wang@mediatek.com wrote: > From: Sean Wang > > The power device is responsible for externally down or up the power > of the remote MediaTek SoC through the tiny circuit BBPU inside PMIC RTC. > > Though it's a part of RTC device, it would be better to be a standalone > driver than to be a part of existent RTC driver so as to let us make > concentration on works about power-controlling topic and to obtain > improvements while the subsystem power/reset constantly growing. I don't understand the above sentence. (I'm fine with adding the driver) > Currently, the most basic functionality supported is to just power off > the system by writing to a special bit field in BBPU register after the > system has reached pm_poweroff. > > Signed-off-by: Sean Wang > --- > drivers/power/reset/Kconfig | 10 ++++ > drivers/power/reset/Makefile | 1 + > drivers/power/reset/mt6323-poweroff.c | 97 +++++++++++++++++++++++++++++++++++ > include/linux/mfd/mt6397/rtc.h | 1 + > 4 files changed, 109 insertions(+) > create mode 100644 drivers/power/reset/mt6323-poweroff.c > > diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig > index df58fc8..7b49d71 100644 > --- a/drivers/power/reset/Kconfig > +++ b/drivers/power/reset/Kconfig > @@ -128,6 +128,16 @@ config POWER_RESET_LTC2952 > This driver supports an external powerdown trigger and board power > down via the LTC2952. Bindings are made in the device tree. > > +config POWER_RESET_MT6323 > + bool "MediaTek MT6323 power-off driver" > + depends on MFD_MT6397 > + help > + The power-off driver is responsible for externally shutdown down > + the power of a remote MediaTek SoC MT6323 is connected to through > + controlling a tiny circuit BBPU inside MT6323 RTC. > + > + Say Y if you have a board where MT6323 could be found. > + > config POWER_RESET_QNAP > bool "QNAP power-off driver" > depends on OF_GPIO && PLAT_ORION > diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile > index 7778c74..8836172 100644 > --- a/drivers/power/reset/Makefile > +++ b/drivers/power/reset/Makefile > @@ -11,6 +11,7 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o > obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o > obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o > obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o > +obj-$(CONFIG_POWER_RESET_MT6323) += mt6323-poweroff.o > obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o > obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o > obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o > diff --git a/drivers/power/reset/mt6323-poweroff.c b/drivers/power/reset/mt6323-poweroff.c > new file mode 100644 > index 0000000..c195766 > --- /dev/null > +++ b/drivers/power/reset/mt6323-poweroff.c > @@ -0,0 +1,97 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Power off through MediaTek PMIC > + * > + * Copyright (C) 2018 MediaTek Inc. > + * > + * Author: Sean Wang > + * > + */ > + > +#include > +#include > +#include Not needed > +#include > +#include > +#include > + > +struct mt6323_pwrc { > + struct device *dev; > + struct regmap *regmap; > + u32 base; > +}; > + > +static struct mt6323_pwrc *mt_pwrc; > + > +static void mt6323_do_pwroff(void) > +{ > + struct mt6323_pwrc *pwrc = mt_pwrc; > + unsigned int val; > + int ret; > + > + regmap_write(pwrc->regmap, pwrc->base + RTC_BBPU, RTC_BBPU_KEY); > + regmap_write(pwrc->regmap, pwrc->base + RTC_WRTGR, 1); > + > + ret = regmap_read_poll_timeout(pwrc->regmap, > + pwrc->base + RTC_BBPU, val, > + !(val & RTC_BBPU_CBUSY), > + MTK_RTC_POLL_DELAY_US, > + MTK_RTC_POLL_TIMEOUT); > + if (ret) > + dev_err(pwrc->dev, "failed to write BBPU: %d\n", ret); > + > + /* Wait some time until system down, otherwise, notice with a warn */ > + mdelay(1000); > + > + WARN_ONCE(1, "Unable to power off system\n"); > +} > + > +static int mt6323_pwrc_probe(struct platform_device *pdev) > +{ > + struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent); > + struct mt6323_pwrc *pwrc; > + struct resource *res; > + > + pwrc = devm_kzalloc(&pdev->dev, sizeof(*pwrc), GFP_KERNEL); > + if (!pwrc) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + pwrc->base = res->start; > + pwrc->regmap = mt6397_chip->regmap; > + pwrc->dev = &pdev->dev; > + mt_pwrc = pwrc; > + > + pm_power_off = &mt6323_do_pwroff; > + > + return 0; > +} > + > +static int mt6323_pwrc_remove(struct platform_device *pdev) > +{ > + if (pm_power_off == &mt6323_do_pwroff) > + pm_power_off = NULL; > + > + return 0; > +} > + > +static const struct of_device_id mt6323_pwrc_dt_match[] = { > + { .compatible = "mediatek,mt6323-pwrc" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, mt6323_pwrc_dt_match); Don't forget to remove the DT table when you respin the series for the requested binding changes. > +static struct platform_driver mt6323_pwrc_driver = { > + .probe = mt6323_pwrc_probe, > + .remove = mt6323_pwrc_remove, > + .driver = { > + .name = "mt6323-pwrc", > + .of_match_table = mt6323_pwrc_dt_match, > + }, > +}; > + > +module_platform_driver(mt6323_pwrc_driver); > + > +MODULE_DESCRIPTION("Poweroff driver for MT6323 PMIC"); > +MODULE_AUTHOR("Sean Wang "); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/linux/mfd/mt6397/rtc.h b/include/linux/mfd/mt6397/rtc.h > index 480977c..ac932c9 100644 > --- a/include/linux/mfd/mt6397/rtc.h > +++ b/include/linux/mfd/mt6397/rtc.h > @@ -16,6 +16,7 @@ > > #define RTC_BBPU 0x0000 > #define RTC_BBPU_CBUSY BIT(6) > +#define RTC_BBPU_KEY (0x43 << 8) > > #define RTC_WRTGR 0x003c The driver looks fine otherwise. -- Sebastian