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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: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Guenter 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: Ralf Baechle <ralf@linux-mips.org>
zero-colors
Hauke Mehrtens 2017-08-20 00:18:11 +02:00 committed by Ralf Baechle
parent 3147f448f7
commit 710322ba8c
1 changed files with 69 additions and 5 deletions

View File

@ -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);