From: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
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 <narmstrong@xxxxxxxxxxxx>
[khilman: rebase to v5.3-rc, rework and modernization]
Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
---
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 e72f65b61176..7cd325ecc10b 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 6b09c21dc1b6..b50fd3aa81b3 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 <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 {
+ 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");
--
2.22.0
