Commit c4f07ece authored by Brian Norris's avatar Brian Norris Committed by Alexandre Belloni
Browse files

rtc: brcmstb-waketimer: Add Broadcom STB wake-timer



This adds support for the Broadcom STB wake-timer which is a timer in
the chip's 27Mhz clock domain that offers the ability to wake the system
(wake-up source) from suspend states (S2, S3, S5). It is supported using
the rtc framework allowing us to configure alarms for system wake-up.
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarMarkus Mayer <mmayer@broadcom.com>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent 3fde00a0
......@@ -197,6 +197,17 @@ config RTC_DRV_AC100
This driver can also be built as a module. If so, the module
will be called rtc-ac100.
config RTC_DRV_BRCMSTB
tristate "Broadcom STB wake-timer"
depends on ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
default ARCH_BRCMSTB || BMIPS_GENERIC
help
If you say yes here you get support for the wake-timer found on
Broadcom STB SoCs (BCM7xxx).
This driver can also be built as a module. If so, the module will
be called rtc-brcmstb-waketimer.
config RTC_DRV_AS3722
tristate "ams AS3722 RTC driver"
depends on MFD_AS3722
......
......@@ -36,6 +36,7 @@ obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o
obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o
obj-$(CONFIG_RTC_DRV_AU1XXX) += rtc-au1xxx.o
obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o
obj-$(CONFIG_RTC_DRV_BRCMSTB) += rtc-brcmstb-waketimer.o
obj-$(CONFIG_RTC_DRV_BQ32K) += rtc-bq32k.o
obj-$(CONFIG_RTC_DRV_BQ4802) += rtc-bq4802.o
obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o
......
/*
* Copyright © 2014-2017 Broadcom
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irqreturn.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_wakeup.h>
#include <linux/reboot.h>
#include <linux/rtc.h>
#include <linux/stat.h>
#include <linux/suspend.h>
struct brcmstb_waketmr {
struct rtc_device *rtc;
struct device *dev;
void __iomem *base;
int irq;
struct notifier_block reboot_notifier;
struct clk *clk;
u32 rate;
};
#define BRCMSTB_WKTMR_EVENT 0x00
#define BRCMSTB_WKTMR_COUNTER 0x04
#define BRCMSTB_WKTMR_ALARM 0x08
#define BRCMSTB_WKTMR_PRESCALER 0x0C
#define BRCMSTB_WKTMR_PRESCALER_VAL 0x10
#define BRCMSTB_WKTMR_DEFAULT_FREQ 27000000
static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
{
writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT);
(void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
}
static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
unsigned int secs)
{
brcmstb_waketmr_clear_alarm(timer);
writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
}
static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
{
struct brcmstb_waketmr *timer = data;
pm_wakeup_event(timer->dev, 0);
return IRQ_HANDLED;
}
struct wktmr_time {
u32 sec;
u32 pre;
};
static void wktmr_read(struct brcmstb_waketmr *timer,
struct wktmr_time *t)
{
u32 tmp;
do {
t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL);
} while (tmp >= timer->rate);
t->pre = timer->rate - tmp;
}
static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
{
struct device *dev = timer->dev;
int ret = 0;
if (device_may_wakeup(dev)) {
ret = enable_irq_wake(timer->irq);
if (ret) {
dev_err(dev, "failed to enable wake-up interrupt\n");
return ret;
}
}
return ret;
}
/* If enabled as a wakeup-source, arm the timer when powering off */
static int brcmstb_waketmr_reboot(struct notifier_block *nb,
unsigned long action, void *data)
{
struct brcmstb_waketmr *timer;
timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);
/* Set timer for cold boot */
if (action == SYS_POWER_OFF)
brcmstb_waketmr_prepare_suspend(timer);
return NOTIFY_DONE;
}
static int brcmstb_waketmr_gettime(struct device *dev,
struct rtc_time *tm)
{
struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
struct wktmr_time now;
wktmr_read(timer, &now);
rtc_time_to_tm(now.sec, tm);
return 0;
}
static int brcmstb_waketmr_settime(struct device *dev,
struct rtc_time *tm)
{
struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
time64_t sec;
sec = rtc_tm_to_time64(tm);
if (sec > U32_MAX || sec < 0)
return -EINVAL;
writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);
return 0;
}
static int brcmstb_waketmr_getalarm(struct device *dev,
struct rtc_wkalrm *alarm)
{
struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
time64_t sec;
u32 reg;
sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
if (sec != 0) {
/* Alarm is enabled */
alarm->enabled = 1;
rtc_time64_to_tm(sec, &alarm->time);
}
reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
alarm->pending = !!(reg & 1);
return 0;
}
static int brcmstb_waketmr_setalarm(struct device *dev,
struct rtc_wkalrm *alarm)
{
struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
time64_t sec;
if (alarm->enabled)
sec = rtc_tm_to_time64(&alarm->time);
else
sec = 0;
if (sec > U32_MAX || sec < 0)
return -EINVAL;
brcmstb_waketmr_set_alarm(timer, sec);
return 0;
}
/*
* Does not do much but keep the RTC class happy. We always support
* alarms.
*/
static int brcmstb_waketmr_alarm_enable(struct device *dev,
unsigned int enabled)
{
return 0;
}
static const struct rtc_class_ops brcmstb_waketmr_ops = {
.read_time = brcmstb_waketmr_gettime,
.set_time = brcmstb_waketmr_settime,
.read_alarm = brcmstb_waketmr_getalarm,
.set_alarm = brcmstb_waketmr_setalarm,
.alarm_irq_enable = brcmstb_waketmr_alarm_enable,
};
static int brcmstb_waketmr_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct brcmstb_waketmr *timer;
struct resource *res;
int ret;
timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
if (!timer)
return -ENOMEM;
platform_set_drvdata(pdev, timer);
timer->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
timer->base = devm_ioremap_resource(dev, res);
if (IS_ERR(timer->base))
return PTR_ERR(timer->base);
/*
* Set wakeup capability before requesting wakeup interrupt, so we can
* process boot-time "wakeups" (e.g., from S5 soft-off)
*/
device_set_wakeup_capable(dev, true);
device_wakeup_enable(dev);
timer->irq = platform_get_irq(pdev, 0);
if (timer->irq < 0)
return -ENODEV;
timer->clk = devm_clk_get(dev, NULL);
if (!IS_ERR(timer->clk)) {
ret = clk_prepare_enable(timer->clk);
if (ret)
return ret;
timer->rate = clk_get_rate(timer->clk);
if (!timer->rate)
timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
} else {
timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
timer->clk = NULL;
}
ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
"brcmstb-waketimer", timer);
if (ret < 0)
return ret;
timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
register_reboot_notifier(&timer->reboot_notifier);
timer->rtc = rtc_device_register("brcmstb-waketmr", dev,
&brcmstb_waketmr_ops, THIS_MODULE);
if (IS_ERR(timer->rtc)) {
dev_err(dev, "unable to register device\n");
unregister_reboot_notifier(&timer->reboot_notifier);
return PTR_ERR(timer->rtc);
}
dev_info(dev, "registered, with irq %d\n", timer->irq);
return ret;
}
static int brcmstb_waketmr_remove(struct platform_device *pdev)
{
struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);
unregister_reboot_notifier(&timer->reboot_notifier);
rtc_device_unregister(timer->rtc);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int brcmstb_waketmr_suspend(struct device *dev)
{
struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
return brcmstb_waketmr_prepare_suspend(timer);
}
static int brcmstb_waketmr_resume(struct device *dev)
{
struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
int ret;
if (!device_may_wakeup(dev))
return 0;
ret = disable_irq_wake(timer->irq);
brcmstb_waketmr_clear_alarm(timer);
return ret;
}
#endif /* CONFIG_PM_SLEEP */
static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops,
brcmstb_waketmr_suspend, brcmstb_waketmr_resume);
static const struct of_device_id brcmstb_waketmr_of_match[] = {
{ .compatible = "brcm,brcmstb-waketimer" },
{ /* sentinel */ },
};
static struct platform_driver brcmstb_waketmr_driver = {
.probe = brcmstb_waketmr_probe,
.remove = brcmstb_waketmr_remove,
.driver = {
.name = "brcmstb-waketimer",
.pm = &brcmstb_waketmr_pm_ops,
.of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
}
};
module_platform_driver(brcmstb_waketmr_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Brian Norris");
MODULE_AUTHOR("Markus Mayer");
MODULE_DESCRIPTION("Wake-up timer driver for STB chips");
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