forked from mirrors/linux
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: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Markus Mayer <mmayer@broadcom.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Brian Norris
Alexandre Belloni
parent
3fde00a014
commit
c4f07ecee2
3 changed files with 342 additions and 0 deletions
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@ -197,6 +197,17 @@ config RTC_DRV_AC100
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This driver can also be built as a module. If so, the module
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will be called rtc-ac100.
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config RTC_DRV_BRCMSTB
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tristate "Broadcom STB wake-timer"
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depends on ARCH_BRCMSTB || BMIPS_GENERIC || COMPILE_TEST
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default ARCH_BRCMSTB || BMIPS_GENERIC
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help
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If you say yes here you get support for the wake-timer found on
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Broadcom STB SoCs (BCM7xxx).
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This driver can also be built as a module. If so, the module will
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be called rtc-brcmstb-waketimer.
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config RTC_DRV_AS3722
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tristate "ams AS3722 RTC driver"
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depends on MFD_AS3722
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@ -36,6 +36,7 @@ obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o
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obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o
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obj-$(CONFIG_RTC_DRV_AU1XXX) += rtc-au1xxx.o
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obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o
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obj-$(CONFIG_RTC_DRV_BRCMSTB) += rtc-brcmstb-waketimer.o
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obj-$(CONFIG_RTC_DRV_BQ32K) += rtc-bq32k.o
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obj-$(CONFIG_RTC_DRV_BQ4802) += rtc-bq4802.o
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obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o
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330
drivers/rtc/rtc-brcmstb-waketimer.c
Normal file
330
drivers/rtc/rtc-brcmstb-waketimer.c
Normal file
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@ -0,0 +1,330 @@
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/*
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* Copyright © 2014-2017 Broadcom
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/clk.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/irqreturn.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/pm_wakeup.h>
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#include <linux/reboot.h>
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#include <linux/rtc.h>
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#include <linux/stat.h>
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#include <linux/suspend.h>
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struct brcmstb_waketmr {
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struct rtc_device *rtc;
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struct device *dev;
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void __iomem *base;
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int irq;
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struct notifier_block reboot_notifier;
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struct clk *clk;
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u32 rate;
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};
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#define BRCMSTB_WKTMR_EVENT 0x00
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#define BRCMSTB_WKTMR_COUNTER 0x04
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#define BRCMSTB_WKTMR_ALARM 0x08
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#define BRCMSTB_WKTMR_PRESCALER 0x0C
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#define BRCMSTB_WKTMR_PRESCALER_VAL 0x10
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#define BRCMSTB_WKTMR_DEFAULT_FREQ 27000000
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static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
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{
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writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT);
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(void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
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}
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static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
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unsigned int secs)
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{
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brcmstb_waketmr_clear_alarm(timer);
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writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
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}
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static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
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{
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struct brcmstb_waketmr *timer = data;
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pm_wakeup_event(timer->dev, 0);
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return IRQ_HANDLED;
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}
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struct wktmr_time {
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u32 sec;
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u32 pre;
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};
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static void wktmr_read(struct brcmstb_waketmr *timer,
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struct wktmr_time *t)
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{
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u32 tmp;
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do {
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t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
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tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL);
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} while (tmp >= timer->rate);
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t->pre = timer->rate - tmp;
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}
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static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
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{
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struct device *dev = timer->dev;
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int ret = 0;
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if (device_may_wakeup(dev)) {
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ret = enable_irq_wake(timer->irq);
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if (ret) {
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dev_err(dev, "failed to enable wake-up interrupt\n");
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return ret;
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}
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}
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return ret;
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}
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/* If enabled as a wakeup-source, arm the timer when powering off */
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static int brcmstb_waketmr_reboot(struct notifier_block *nb,
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unsigned long action, void *data)
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{
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struct brcmstb_waketmr *timer;
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timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);
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/* Set timer for cold boot */
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if (action == SYS_POWER_OFF)
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brcmstb_waketmr_prepare_suspend(timer);
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return NOTIFY_DONE;
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}
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static int brcmstb_waketmr_gettime(struct device *dev,
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struct rtc_time *tm)
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{
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struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
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struct wktmr_time now;
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wktmr_read(timer, &now);
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rtc_time_to_tm(now.sec, tm);
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return 0;
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}
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static int brcmstb_waketmr_settime(struct device *dev,
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struct rtc_time *tm)
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{
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struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
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time64_t sec;
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sec = rtc_tm_to_time64(tm);
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if (sec > U32_MAX || sec < 0)
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return -EINVAL;
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writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);
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return 0;
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}
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static int brcmstb_waketmr_getalarm(struct device *dev,
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struct rtc_wkalrm *alarm)
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{
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struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
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time64_t sec;
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u32 reg;
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sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
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if (sec != 0) {
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/* Alarm is enabled */
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alarm->enabled = 1;
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rtc_time64_to_tm(sec, &alarm->time);
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}
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reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
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alarm->pending = !!(reg & 1);
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return 0;
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}
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static int brcmstb_waketmr_setalarm(struct device *dev,
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struct rtc_wkalrm *alarm)
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{
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struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
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time64_t sec;
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if (alarm->enabled)
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sec = rtc_tm_to_time64(&alarm->time);
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else
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sec = 0;
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if (sec > U32_MAX || sec < 0)
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return -EINVAL;
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brcmstb_waketmr_set_alarm(timer, sec);
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return 0;
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}
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/*
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* Does not do much but keep the RTC class happy. We always support
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* alarms.
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*/
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static int brcmstb_waketmr_alarm_enable(struct device *dev,
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unsigned int enabled)
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{
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return 0;
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}
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static const struct rtc_class_ops brcmstb_waketmr_ops = {
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.read_time = brcmstb_waketmr_gettime,
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.set_time = brcmstb_waketmr_settime,
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.read_alarm = brcmstb_waketmr_getalarm,
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.set_alarm = brcmstb_waketmr_setalarm,
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.alarm_irq_enable = brcmstb_waketmr_alarm_enable,
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};
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static int brcmstb_waketmr_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct brcmstb_waketmr *timer;
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struct resource *res;
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int ret;
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timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
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if (!timer)
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return -ENOMEM;
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platform_set_drvdata(pdev, timer);
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timer->dev = dev;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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timer->base = devm_ioremap_resource(dev, res);
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if (IS_ERR(timer->base))
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return PTR_ERR(timer->base);
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/*
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* Set wakeup capability before requesting wakeup interrupt, so we can
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* process boot-time "wakeups" (e.g., from S5 soft-off)
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*/
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device_set_wakeup_capable(dev, true);
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device_wakeup_enable(dev);
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timer->irq = platform_get_irq(pdev, 0);
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if (timer->irq < 0)
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return -ENODEV;
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timer->clk = devm_clk_get(dev, NULL);
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if (!IS_ERR(timer->clk)) {
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ret = clk_prepare_enable(timer->clk);
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if (ret)
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return ret;
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timer->rate = clk_get_rate(timer->clk);
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if (!timer->rate)
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timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
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} else {
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timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
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timer->clk = NULL;
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}
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ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
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"brcmstb-waketimer", timer);
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if (ret < 0)
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return ret;
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timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
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register_reboot_notifier(&timer->reboot_notifier);
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timer->rtc = rtc_device_register("brcmstb-waketmr", dev,
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&brcmstb_waketmr_ops, THIS_MODULE);
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if (IS_ERR(timer->rtc)) {
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dev_err(dev, "unable to register device\n");
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unregister_reboot_notifier(&timer->reboot_notifier);
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return PTR_ERR(timer->rtc);
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}
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dev_info(dev, "registered, with irq %d\n", timer->irq);
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return ret;
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}
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static int brcmstb_waketmr_remove(struct platform_device *pdev)
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{
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struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);
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unregister_reboot_notifier(&timer->reboot_notifier);
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rtc_device_unregister(timer->rtc);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int brcmstb_waketmr_suspend(struct device *dev)
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{
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struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
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return brcmstb_waketmr_prepare_suspend(timer);
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}
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static int brcmstb_waketmr_resume(struct device *dev)
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{
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struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
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int ret;
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if (!device_may_wakeup(dev))
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return 0;
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ret = disable_irq_wake(timer->irq);
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brcmstb_waketmr_clear_alarm(timer);
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return ret;
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}
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#endif /* CONFIG_PM_SLEEP */
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static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops,
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brcmstb_waketmr_suspend, brcmstb_waketmr_resume);
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static const struct of_device_id brcmstb_waketmr_of_match[] = {
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{ .compatible = "brcm,brcmstb-waketimer" },
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{ /* sentinel */ },
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};
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static struct platform_driver brcmstb_waketmr_driver = {
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.probe = brcmstb_waketmr_probe,
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.remove = brcmstb_waketmr_remove,
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.driver = {
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.name = "brcmstb-waketimer",
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.pm = &brcmstb_waketmr_pm_ops,
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.of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
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}
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};
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module_platform_driver(brcmstb_waketmr_driver);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Brian Norris");
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MODULE_AUTHOR("Markus Mayer");
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MODULE_DESCRIPTION("Wake-up timer driver for STB chips");
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