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author | Neil Armstrong <narmstrong@baylibre.com> | 2019-08-12 16:28:50 -0700 |
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committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-08-22 23:08:32 +0200 |
commit | 6ef35398e827dcf321a012c8f7a4d8d739674db6 (patch) | |
tree | 909abba1d080bff56d0f0a76d291eeee0cd6c5e9 /drivers/rtc/rtc-meson-vrtc.c | |
parent | ed16239637f6656d3e6656ed1753e70d7823d94f (diff) | |
download | linux-6ef35398e827dcf321a012c8f7a4d8d739674db6.tar.gz linux-6ef35398e827dcf321a012c8f7a4d8d739674db6.tar.bz2 linux-6ef35398e827dcf321a012c8f7a4d8d739674db6.zip |
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 <narmstrong@baylibre.com>
[khilman: rebase to v5.3-rc, rework and modernization]
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20190812232850.8016-3-khilman@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc/rtc-meson-vrtc.c')
-rw-r--r-- | drivers/rtc/rtc-meson-vrtc.c | 156 |
1 files changed, 156 insertions, 0 deletions
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@baylibre.com> + * 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"); |