Commit 1a71fb84 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wim Van Sebroeck
Browse files

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: default avatarWolfram Sang <w.sang@pengutronix.de>
Acked-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarWim 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 */

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