From: Neil Armstrong <narmstrong@xxxxxxxxxxxx> The 64-bit Amlogic SoCs uses a special register to store the time in seconds to wakeup after a system suspend. In order to be able to reuse the RTC wakealarm feature, this driver implements a fake RTC device which uses the system time to deduce a suspend delay. Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx> [khilman: rebase to v5.2-rc, moved from do_gettimeofday()] Tested-by: Kevin Hilman <khilman@xxxxxxxxxxxx> Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxx> --- Originally written/sumbmitted by Neil as part of a broader/suspend resume series[1] for the GXBB family. Newer SoCs support PSCI properly, so don't need the PSCI changes there, and this driver alone enables RTC wakeups from suspend. [1] https://lore.kernel.org/lkml/1478183365-23708-1-git-send-email-narmstrong@xxxxxxxxxxxx/ drivers/rtc/Kconfig | 11 +++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-meson-vrtc.c | 149 +++++++++++++++++++++++++++++++++++ 3 files changed, 161 insertions(+) create mode 100644 drivers/rtc/rtc-meson-vrtc.c diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 5c0790eed656..78d2967d5ee3 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -373,6 +373,17 @@ config RTC_DRV_MAX77686 This driver can also be built as a module. If so, the module will be called rtc-max77686. +config RTC_DRV_MESON_VRTC + tristate "Amlogic Meson Virtual RTC" + depends on ARCH_MESON || COMPILE_TEST + default m if ARCH_MESON + help + If you say yes here you will get support for the + Virtual RTC of Amlogic SoCs. + + This driver can also be built as a module. If so, the module + will be called rtc-meson-vrtc. + config RTC_DRV_RK808 tristate "Rockchip RK805/RK808/RK818 RTC" depends on MFD_RK808 diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 9d997faa2c26..9485fb46b023 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -101,6 +101,7 @@ obj-$(CONFIG_RTC_DRV_MAX8907) += rtc-max8907.o obj-$(CONFIG_RTC_DRV_MAX8925) += rtc-max8925.o obj-$(CONFIG_RTC_DRV_MAX8997) += rtc-max8997.o obj-$(CONFIG_RTC_DRV_MAX8998) += rtc-max8998.o +obj-$(CONFIG_RTC_DRV_MESON_VRTC)+= rtc-meson-vrtc.o obj-$(CONFIG_RTC_DRV_MC13XXX) += rtc-mc13xxx.o obj-$(CONFIG_RTC_DRV_MCP795) += rtc-mcp795.o obj-$(CONFIG_RTC_DRV_MESON) += rtc-meson.o diff --git a/drivers/rtc/rtc-meson-vrtc.c b/drivers/rtc/rtc-meson-vrtc.c new file mode 100644 index 000000000000..f695f65ab199 --- /dev/null +++ b/drivers/rtc/rtc-meson-vrtc.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 BayLibre, SAS + * Author: Neil Armstrong <narmstrong@xxxxxxxxxxxx> + * Copyright (C) 2015 Amlogic, Inc. All rights reserved. + */ +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/time64.h> + +struct meson_vrtc_data { + struct platform_device *pdev; + void __iomem *io_alarm; + struct rtc_device *rtc; + unsigned long alarm_time; +}; + +static int meson_vrtc_read_time(struct device *dev, struct rtc_time *tm) +{ + unsigned long local_time; + struct timespec64 time; + + ktime_get_raw_ts64(&time); + local_time = time.tv_sec - (sys_tz.tz_minuteswest * 60); + rtc_time_to_tm(local_time, tm); + + return 0; +} + +static void meson_vrtc_set_wakeup_time(struct meson_vrtc_data *vrtc, + unsigned long time) +{ + writel_relaxed(time, vrtc->io_alarm); + + dev_dbg(&vrtc->pdev->dev, "set_wakeup_time: %lu\n", time); +} + +static int meson_vrtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct meson_vrtc_data *vrtc = dev_get_drvdata(dev); + struct timespec64 time; + unsigned long local_time; + unsigned long alarm_secs; + int ret; + + if (alarm->enabled) { + ret = rtc_tm_to_time(&alarm->time, &alarm_secs); + if (ret) + return ret; + + ktime_get_raw_ts64(&time); + local_time = time.tv_sec - (sys_tz.tz_minuteswest * 60); + + vrtc->alarm_time = alarm_secs; + + if (alarm_secs >= local_time) { + alarm_secs = alarm_secs - local_time; + + meson_vrtc_set_wakeup_time(vrtc, alarm_secs); + + pr_debug("system will wakeup %lus later\n", alarm_secs); + } + } else { + vrtc->alarm_time = 0; + meson_vrtc_set_wakeup_time(vrtc, 0); + } + + return 0; +} + +static int meson_vrtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct meson_vrtc_data *vrtc = dev_get_drvdata(dev); + + if (!vrtc->alarm_time) { + alm->enabled = true; + + rtc_time_to_tm(vrtc->alarm_time, &alm->time); + } + + return 0; +} + +static const struct rtc_class_ops meson_vrtc_ops = { + .read_time = meson_vrtc_read_time, + .set_alarm = meson_vrtc_set_alarm, + .read_alarm = meson_vrtc_read_alarm, +}; + +static int meson_vrtc_probe(struct platform_device *pdev) +{ + struct meson_vrtc_data *vrtc; + struct resource *res; + + vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL); + if (!vrtc) + return -ENOMEM; + + vrtc->pdev = pdev; + + /* Alarm registers */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + vrtc->io_alarm = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(vrtc->io_alarm)) + return PTR_ERR(vrtc->io_alarm); + + device_init_wakeup(&pdev->dev, 1); + + platform_set_drvdata(pdev, vrtc); + + vrtc->rtc = devm_rtc_device_register(&pdev->dev, "meson-vrtc", + &meson_vrtc_ops, THIS_MODULE); + if (IS_ERR(vrtc->rtc)) + return PTR_ERR(vrtc->rtc); + + return 0; +} + +int meson_vrtc_resume(struct platform_device *pdev) +{ + struct meson_vrtc_data *vrtc = platform_get_drvdata(pdev); + + meson_vrtc_set_wakeup_time(vrtc, 0); + + return 0; +} + +static const struct of_device_id meson_vrtc_dt_match[] = { + { .compatible = "amlogic,meson-vrtc"}, + {}, +}; +MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match); + +struct platform_driver meson_vrtc_driver = { + .driver = { + .name = "meson-vrtc", + .of_match_table = meson_vrtc_dt_match, + }, + .probe = meson_vrtc_probe, + .resume = meson_vrtc_resume, +}; + +module_platform_driver(meson_vrtc_driver); + +MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver"); +MODULE_LICENSE("GPL"); -- 2.21.0
