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Commit 710322ba authored by Hauke Mehrtens's avatar Hauke Mehrtens Committed by Ralf Baechle
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watchdog: lantiq: access boot cause register through regmap 



This patch avoids accessing the function ltq_reset_cause() and directly
accesses the register given over the syscon interface. The syscon
interface will be implemented for the xway SoCs for the falcon SoCs the
ltq_reset_cause() function never worked, because a wrong offset was used.

Signed-off-by: default avatarHauke Mehrtens <hauke@hauke-m.de>
Acked-by: default avatarGuenter Roeck <linux@reck-us.net>
Cc: martin.blumenstingl@googlemail.com
Cc: john@phrozen.org
Cc: robh@kernel.org
Cc: andy.shevchenko@gmail.com
Cc: p.zabel@pengutronix.de
Cc: kishon@ti.com
Cc: mark.rutland@arm.com
Cc: linux-mips@linux-mips.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-watchdog@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17123/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 3147f448

drivers/watchdog/lantiq_wdt.c

+69 −5
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 *  by the Free Software Foundation.

 *

 *  Copyright (C) 2010 John Crispin <john@phrozen.org>

 *  Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>

 *  Based on EP93xx wdt driver

 */
@@ -17,9 +18,20 @@ 
#include <linux/uaccess.h>

#include <linux/clk.h>

#include <linux/io.h>

#include <linux/regmap.h>

#include <linux/mfd/syscon.h>



#include <lantiq_soc.h>



#define LTQ_XRX_RCU_RST_STAT		0x0014

#define LTQ_XRX_RCU_RST_STAT_WDT	BIT(31)



/* CPU0 Reset Source Register */

#define LTQ_FALCON_SYS1_CPU0RS		0x0060

/* reset cause mask */

#define LTQ_FALCON_SYS1_CPU0RS_MASK	0x0007

#define LTQ_FALCON_SYS1_CPU0RS_WDT	0x02



/*

 * Section 3.4 of the datasheet

 * The password sequence protects the WDT control register from unintended
@@ -186,16 +198,70 @@ static struct miscdevice ltq_wdt_miscdev = { 
	.fops	= &ltq_wdt_fops,

};



typedef int (*ltq_wdt_bootstatus_set)(struct platform_device *pdev);



static int ltq_wdt_bootstatus_xrx(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct regmap *rcu_regmap;

	u32 val;

	int err;



	rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");

	if (IS_ERR(rcu_regmap))

		return PTR_ERR(rcu_regmap);



	err = regmap_read(rcu_regmap, LTQ_XRX_RCU_RST_STAT, &val);

	if (err)

		return err;



	if (val & LTQ_XRX_RCU_RST_STAT_WDT)

		ltq_wdt_bootstatus = WDIOF_CARDRESET;



	return 0;

}



static int ltq_wdt_bootstatus_falcon(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct regmap *rcu_regmap;

	u32 val;

	int err;



	rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,

						     "lantiq,rcu");

	if (IS_ERR(rcu_regmap))

		return PTR_ERR(rcu_regmap);



	err = regmap_read(rcu_regmap, LTQ_FALCON_SYS1_CPU0RS, &val);

	if (err)

		return err;



	if ((val & LTQ_FALCON_SYS1_CPU0RS_MASK) == LTQ_FALCON_SYS1_CPU0RS_WDT)

		ltq_wdt_bootstatus = WDIOF_CARDRESET;



	return 0;

}



static int

ltq_wdt_probe(struct platform_device *pdev)

{

	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	struct clk *clk;

	ltq_wdt_bootstatus_set ltq_wdt_bootstatus_set;

	int ret;



	ltq_wdt_membase = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(ltq_wdt_membase))

		return PTR_ERR(ltq_wdt_membase);



	ltq_wdt_bootstatus_set = of_device_get_match_data(&pdev->dev);

	if (ltq_wdt_bootstatus_set) {

		ret = ltq_wdt_bootstatus_set(pdev);

		if (ret)

			return ret;

	}



	/* we do not need to enable the clock as it is always running */

	clk = clk_get_io();

	if (IS_ERR(clk)) {
@@ -205,10 +271,6 @@ ltq_wdt_probe(struct platform_device *pdev) 
	ltq_io_region_clk_rate = clk_get_rate(clk);

	clk_put(clk);



	/* find out if the watchdog caused the last reboot */

	if (ltq_reset_cause() == LTQ_RST_CAUSE_WDTRST)

		ltq_wdt_bootstatus = WDIOF_CARDRESET;



	dev_info(&pdev->dev, "Init done\n");

	return misc_register(&ltq_wdt_miscdev);

}
@@ -222,7 +284,9 @@ ltq_wdt_remove(struct platform_device *pdev) 
}



static const struct of_device_id ltq_wdt_match[] = {

	{ .compatible = "lantiq,wdt" },

	{ .compatible = "lantiq,wdt", .data = NULL},

	{ .compatible = "lantiq,xrx100-wdt", .data = ltq_wdt_bootstatus_xrx },

	{ .compatible = "lantiq,falcon-wdt", .data = ltq_wdt_bootstatus_falcon },

	{},

};

MODULE_DEVICE_TABLE(of, ltq_wdt_match);