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Commit 1a71fb84 authored Sep 27, 2011 by Wolfram Sang Committed by Wim Van Sebroeck Mar 01, 2013

rtc: stmp3xxx: add wdt-accessor function



This RTC also includes a watchdog timer. Provide an accessor function
for setting the watchdog timeout value which will be picked up by a
watchdog driver. Also register the platform_device for the watchdog here
to get the boot-time dependencies right.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

parent 3d3a6d18

drivers/rtc/rtc-stmp3xxx.c

+64 −0

Original line number	Diff line number	Diff line
		@@ -27,6 +27,8 @@
		#include <linux/slab.h>
		#include <linux/of_device.h>
		#include <linux/of.h>
		#include <linux/stmp_device.h>
		#include <linux/stmp3xxx_rtc_wdt.h>

		#include <mach/common.h>

		@@ -36,6 +38,7 @@
		#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001
		#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002
		#define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004
		#define STMP3XXX_RTC_CTRL_WATCHDOGEN 0x00000010

		#define STMP3XXX_RTC_STAT 0x10
		#define STMP3XXX_RTC_STAT_STALE_SHIFT 16
		@@ -45,6 +48,8 @@

		#define STMP3XXX_RTC_ALARM 0x40

		#define STMP3XXX_RTC_WATCHDOG 0x50

		#define STMP3XXX_RTC_PERSISTENT0 0x60
		#define STMP3XXX_RTC_PERSISTENT0_SET 0x64
		#define STMP3XXX_RTC_PERSISTENT0_CLR 0x68
		@@ -52,12 +57,70 @@
		#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004
		#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080

		#define STMP3XXX_RTC_PERSISTENT1 0x70
		/* missing bitmask in headers */
		#define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER 0x80000000

		struct stmp3xxx_rtc_data {
		struct rtc_device *rtc;
		void __iomem *io;
		int irq_alarm;
		};

		#if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG)
		/**
		* stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC
		* @dev: the parent device of the watchdog (= the RTC)
		* @timeout: the desired value for the timeout register of the watchdog.
		* 0 disables the watchdog
		*
		* The watchdog needs one register and two bits which are in the RTC domain.
		* To handle the resource conflict, the RTC driver will create another
		* platform_device for the watchdog driver as a child of the RTC device.
		* The watchdog driver is passed the below accessor function via platform_data
		* to configure the watchdog. Locking is not needed because accessing SET/CLR
		* registers is atomic.
		*/

		static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout)
		{
		struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);

		if (timeout) {
		writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG);
		writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
		rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET);
		writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
		rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET);
		} else {
		writel(STMP3XXX_RTC_CTRL_WATCHDOGEN,
		rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR);
		writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER,
		rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR);
		}
		}

		static struct stmp3xxx_wdt_pdata wdt_pdata = {
		.wdt_set_timeout = stmp3xxx_wdt_set_timeout,
		};

		static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
		{
		struct platform_device *wdt_pdev =
		platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id);

		if (wdt_pdev) {
		wdt_pdev->dev.parent = &rtc_pdev->dev;
		wdt_pdev->dev.platform_data = &wdt_pdata;
		platform_device_add(wdt_pdev);
		}
		}
		#else
		static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev)
		{
		}
		#endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */

		static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
		{
		/*
		@@ -233,6 +296,7 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev)
		goto out_irq_alarm;
		}

		stmp3xxx_wdt_register(pdev);
		return 0;

		out_irq_alarm:

include/linux/stmp3xxx_rtc_wdt.h

0 → 100644

+15 −0

Original line number	Diff line number	Diff line
		/*
		* stmp3xxx_rtc_wdt.h
		*
		* Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
		*
		* This file is released under the GPLv2.
		*/
		#ifndef __LINUX_STMP3XXX_RTC_WDT_H
		#define __LINUX_STMP3XXX_RTC_WDT_H

		struct stmp3xxx_wdt_pdata {
		void (wdt_set_timeout)(struct device dev, u32 timeout);
		};

		#endif /* __LINUX_STMP3XXX_RTC_WDT_H */