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Commit 39487f66 authored by Vladimir Zapolskiy's avatar Vladimir Zapolskiy Committed by Wim Van Sebroeck
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watchdog: imx2_wdt: add pretimeout function support 



The change adds watchdog pretimeout notification handling to imx2_wdt
driver, if device data contains information about a valid interrupt.

It is unlikely but still possible (e.g. through a software limitation)
that only a subset of watchdogs on SoC has interrupt lines, hence
functionally the devices from these two groups have different
capabilities, and this is reflected in different watchdog_info
structs assigned to the devices.

Signed-off-by: default avatarVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 2accf320

drivers/watchdog/imx2_wdt.c

+48 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/clk.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/module.h>
@@ -50,6 +51,11 @@ 
#define IMX2_WDT_WRSR		0x04		/* Reset Status Register */

#define IMX2_WDT_WRSR_TOUT	BIT(1)		/* -> Reset due to Timeout */



#define IMX2_WDT_WICR		0x06		/* Interrupt Control Register */

#define IMX2_WDT_WICR_WIE	BIT(15)		/* -> Interrupt Enable */

#define IMX2_WDT_WICR_WTIS	BIT(14)		/* -> Interrupt Status */

#define IMX2_WDT_WICR_WICT	0xFF		/* -> Interrupt Count Timeout */



#define IMX2_WDT_WMCR		0x08		/* Misc Register */



#define IMX2_WDT_MAX_TIME	128
@@ -80,6 +86,12 @@ static const struct watchdog_info imx2_wdt_info = { 
	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,

};



static const struct watchdog_info imx2_wdt_pretimeout_info = {

	.identity = "imx2+ watchdog",

	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |

		   WDIOF_PRETIMEOUT,

};



static int imx2_wdt_restart(struct watchdog_device *wdog, unsigned long action,

			    void *data)

{
@@ -169,6 +181,35 @@ static int imx2_wdt_set_timeout(struct watchdog_device *wdog, 
	return 0;

}



static int imx2_wdt_set_pretimeout(struct watchdog_device *wdog,

				   unsigned int new_pretimeout)

{

	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);



	if (new_pretimeout >= IMX2_WDT_MAX_TIME)

		return -EINVAL;



	wdog->pretimeout = new_pretimeout;



	regmap_update_bits(wdev->regmap, IMX2_WDT_WICR,

			   IMX2_WDT_WICR_WIE | IMX2_WDT_WICR_WICT,

			   IMX2_WDT_WICR_WIE | (new_pretimeout << 1));

	return 0;

}



static irqreturn_t imx2_wdt_isr(int irq, void *wdog_arg)

{

	struct watchdog_device *wdog = wdog_arg;

	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);



	regmap_write_bits(wdev->regmap, IMX2_WDT_WICR,

			  IMX2_WDT_WICR_WTIS, IMX2_WDT_WICR_WTIS);



	watchdog_notify_pretimeout(wdog);



	return IRQ_HANDLED;

}



static int imx2_wdt_start(struct watchdog_device *wdog)

{

	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
@@ -188,6 +229,7 @@ static const struct watchdog_ops imx2_wdt_ops = { 
	.start = imx2_wdt_start,

	.ping = imx2_wdt_ping,

	.set_timeout = imx2_wdt_set_timeout,

	.set_pretimeout = imx2_wdt_set_pretimeout,

	.restart = imx2_wdt_restart,

};
@@ -236,6 +278,12 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) 
	wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000;

	wdog->parent		= &pdev->dev;



	ret = platform_get_irq(pdev, 0);

	if (ret > 0)

		if (!devm_request_irq(&pdev->dev, ret, imx2_wdt_isr, 0,

				      dev_name(&pdev->dev), wdog))

			wdog->info = &imx2_wdt_pretimeout_info;



	ret = clk_prepare_enable(wdev->clk);

	if (ret)

		return ret;