watchdog: mt7621-wdt: avoid ralink architecture dependent code

MT7621 SoC has a system controller node. Watchdog need to access to reset
status register. Ralink architecture and related driver are old and from
the beggining they are using some architecture dependent operations for
accessing this shared registers through 'asm/mach-ralink/ralink_regs.h'
header file. However this is not ideal from a driver perspective which can
just access to the system controller registers in an arch independent way
using regmap syscon APIs. Update Kconfig accordingly to select new added
dependencies and allow driver to be compile tested.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230214103936.1061078-6-sergio.paracuellos@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 0bc40b763b065210998eb886ec7192773016d535..3df3638ac8b0c431b8feaa44c9f72d5ebc9f40b2 100644 (file)
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1872,7 +1872,9 @@ config GXP_WATCHDOG
 config MT7621_WDT
        tristate "Mediatek SoC watchdog"
        select WATCHDOG_CORE
-       depends on SOC_MT7620 || SOC_MT7621
+       select REGMAP_MMIO
+       select MFD_SYSCON
+       depends on SOC_MT7620 || SOC_MT7621 || COMPILE_TEST
        help
          Hardware driver for the Mediatek/Ralink MT7621/8 SoC Watchdog Timer.
 

diff --git a/drivers/watchdog/mt7621_wdt.c b/drivers/watchdog/mt7621_wdt.c
index b02c1415fc716efbbc523e634d8d3ed6a9e99ed1..442731bba19469f5e61c0e7dc7351d4703d85beb 100644 (file)
--- a/drivers/watchdog/mt7621_wdt.c
+++ b/drivers/watchdog/mt7621_wdt.c
@@ -15,8 +15,8 @@
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
 #include <linux/mod_devicetable.h>
-
-#include <asm/mach-ralink/ralink_regs.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #define SYSC_RSTSTAT                   0x38
 #define WDT_RST_CAUSE                  BIT(1)
@@ -34,6 +34,7 @@
 struct mt7621_wdt_data {
        void __iomem *base;
        struct reset_control *rst;
+       struct regmap *sysc;
        struct watchdog_device wdt;
 };
 
@@ -104,9 +105,12 @@ static int mt7621_wdt_stop(struct watchdog_device *w)
        return 0;
 }
 
-static int mt7621_wdt_bootcause(void)
+static int mt7621_wdt_bootcause(struct mt7621_wdt_data *d)
 {
-       if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
+       u32 val;
+
+       regmap_read(d->sysc, SYSC_RSTSTAT, &val);
+       if (val & WDT_RST_CAUSE)
                return WDIOF_CARDRESET;
 
        return 0;
@@ -134,6 +138,7 @@ static const struct watchdog_ops mt7621_wdt_ops = {
 
 static int mt7621_wdt_probe(struct platform_device *pdev)
 {
+       struct device_node *np = pdev->dev.of_node;
        struct device *dev = &pdev->dev;
        struct watchdog_device *mt7621_wdt;
        struct mt7621_wdt_data *drvdata;
@@ -143,6 +148,13 @@ static int mt7621_wdt_probe(struct platform_device *pdev)
        if (!drvdata)
                return -ENOMEM;
 
+       drvdata->sysc = syscon_regmap_lookup_by_phandle(np, "mediatek,sysctl");
+       if (IS_ERR(drvdata->sysc)) {
+               drvdata->sysc = syscon_regmap_lookup_by_compatible("mediatek,mt7621-sysc");
+               if (IS_ERR(drvdata->sysc))
+                       return PTR_ERR(drvdata->sysc);
+       }
+
        drvdata->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(drvdata->base))
                return PTR_ERR(drvdata->base);
@@ -158,7 +170,7 @@ static int mt7621_wdt_probe(struct platform_device *pdev)
        mt7621_wdt->max_timeout = 0xfffful / 1000;
        mt7621_wdt->parent = dev;
 
-       mt7621_wdt->bootstatus = mt7621_wdt_bootcause();
+       mt7621_wdt->bootstatus = mt7621_wdt_bootcause(drvdata);
 
        watchdog_init_timeout(mt7621_wdt, mt7621_wdt->max_timeout, dev);
        watchdog_set_nowayout(mt7621_wdt, nowayout);