From 6ef35398e827dcf321a012c8f7a4d8d739674db6 Mon Sep 17 00:00:00 2001 From: Neil Armstrong Date: Mon, 12 Aug 2019 16:28:50 -0700 Subject: [PATCH] rtc: Add Amlogic Virtual Wake RTC The Amlogic Meson GX 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 [khilman: rebase to v5.3-rc, rework and modernization] Signed-off-by: Kevin Hilman Link: https://lore.kernel.org/r/20190812232850.8016-3-khilman@kernel.org Signed-off-by: Alexandre Belloni --- MAINTAINERS | 1 + drivers/rtc/Kconfig | 11 +++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-meson-vrtc.c | 156 +++++++++++++++++++++++++++++++++++ 4 files changed, 169 insertions(+) create mode 100644 drivers/rtc/rtc-meson-vrtc.c diff --git a/MAINTAINERS b/MAINTAINERS index 783569e3c4b4..2ae83e1acb05 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1443,6 +1443,7 @@ F: arch/arm64/boot/dts/amlogic/ F: drivers/pinctrl/meson/ F: drivers/mmc/host/meson* F: drivers/soc/amlogic/ +F: drivers/rtc/rtc-meson* N: meson ARM/Amlogic Meson SoC Sound Drivers diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 24d16030d60c..59fbf8b761b9 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/RK809/RK817/RK818 RTC" depends on MFD_RK808 diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 9fe0e938272c..bd87a004b346 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -102,6 +102,7 @@ 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..4621a4715179 --- /dev/null +++ b/drivers/rtc/rtc-meson-vrtc.c @@ -0,0 +1,156 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 BayLibre, SAS + * Author: Neil Armstrong + * Copyright (C) 2015 Amlogic, Inc. All rights reserved. + */ +#include +#include +#include +#include +#include +#include + +struct meson_vrtc_data { + void __iomem *io_alarm; + struct rtc_device *rtc; + unsigned long alarm_time; + bool enabled; +}; + +static int meson_vrtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct timespec64 time; + + dev_dbg(dev, "%s\n", __func__); + ktime_get_raw_ts64(&time); + rtc_time64_to_tm(time.tv_sec, tm); + + return 0; +} + +static void meson_vrtc_set_wakeup_time(struct meson_vrtc_data *vrtc, + unsigned long time) +{ + writel_relaxed(time, vrtc->io_alarm); +} + +static int meson_vrtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct meson_vrtc_data *vrtc = dev_get_drvdata(dev); + + dev_dbg(dev, "%s: alarm->enabled=%d\n", __func__, alarm->enabled); + if (alarm->enabled) + vrtc->alarm_time = rtc_tm_to_time64(&alarm->time); + else + vrtc->alarm_time = 0; + + return 0; +} + +static int meson_vrtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct meson_vrtc_data *vrtc = dev_get_drvdata(dev); + + vrtc->enabled = enabled; + return 0; +} + +static const struct rtc_class_ops meson_vrtc_ops = { + .read_time = meson_vrtc_read_time, + .set_alarm = meson_vrtc_set_alarm, + .alarm_irq_enable = meson_vrtc_alarm_irq_enable, +}; + +static int meson_vrtc_probe(struct platform_device *pdev) +{ + struct meson_vrtc_data *vrtc; + int ret; + + vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL); + if (!vrtc) + return -ENOMEM; + + vrtc->io_alarm = devm_platform_ioremap_resource(pdev, 0); + 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_allocate_device(&pdev->dev); + if (IS_ERR(vrtc->rtc)) + return PTR_ERR(vrtc->rtc); + + vrtc->rtc->ops = &meson_vrtc_ops; + ret = rtc_register_device(vrtc->rtc); + if (ret) + return ret; + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int meson_vrtc_suspend(struct device *dev) +{ + struct meson_vrtc_data *vrtc = dev_get_drvdata(dev); + + dev_dbg(dev, "%s\n", __func__); + if (vrtc->alarm_time) { + unsigned long local_time; + long alarm_secs; + struct timespec64 time; + + ktime_get_raw_ts64(&time); + local_time = time.tv_sec; + + dev_dbg(dev, "alarm_time = %lus, local_time=%lus\n", + vrtc->alarm_time, local_time); + alarm_secs = vrtc->alarm_time - local_time; + if (alarm_secs > 0) { + meson_vrtc_set_wakeup_time(vrtc, alarm_secs); + dev_dbg(dev, "system will wakeup in %lds.\n", + alarm_secs); + } else { + dev_err(dev, "alarm time already passed: %lds.\n", + alarm_secs); + } + } + + return 0; +} + +static int meson_vrtc_resume(struct device *dev) +{ + struct meson_vrtc_data *vrtc = dev_get_drvdata(dev); + + dev_dbg(dev, "%s\n", __func__); + + vrtc->alarm_time = 0; + meson_vrtc_set_wakeup_time(vrtc, 0); + return 0; +} +#endif +static SIMPLE_DEV_PM_OPS(meson_vrtc_pm_ops, + meson_vrtc_suspend, meson_vrtc_resume); + +static const struct of_device_id meson_vrtc_dt_match[] = { + { .compatible = "amlogic,meson-vrtc"}, + {}, +}; +MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match); + +static struct platform_driver meson_vrtc_driver = { + .probe = meson_vrtc_probe, + .driver = { + .name = "meson-vrtc", + .of_match_table = meson_vrtc_dt_match, + .pm = &meson_vrtc_pm_ops, + }, +}; + +module_platform_driver(meson_vrtc_driver); + +MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver"); +MODULE_LICENSE("GPL");