ramips: mt7621-wdt: use phandle to access system controller registers

These patches allow the driver to access some watchdog registers via a
phandle to the system controller node[1]. To apply these changes, we
need to add "mediatek,sysctl" to the SoC dtsi. This commit also remove
the redundent clocks, interrupts and resets properties.

[1] https://lore.kernel.org/all/20230214103936.1061078-2-sergio.paracuellos@gmail.com

Tested on Motorola MWR03 (MT7628)

Signed-off-by: Shiji Yang <yangshiji66@qq.com>

4 files changed, 322 insertions, 11 deletions

diff --git a/target/linux/ramips/dts/mt7621.dtsi b/target/linux/ramips/dts/mt7621.dtsi
index 84a7b306a7..f1f77282b2 100644
--- a/target/linux/ramips/dts/mt7621.dtsi
+++ b/target/linux/ramips/dts/mt7621.dtsi
@@ -61,9 +61,10 @@
 			reg = <0x0 0x100>;
 		};
 
-		wdt: wdt@100 {
+		wdt: watchdog@100 {
 			compatible = "mediatek,mt7621-wdt";
 			reg = <0x100 0x100>;
+			mediatek,sysctl = <&sysc>;
 		};
 
 		gpio: gpio@600 {
diff --git a/target/linux/ramips/dts/mt7628an.dtsi b/target/linux/ramips/dts/mt7628an.dtsi
index 74d2c980b5..d6c3a47b0b 100644
--- a/target/linux/ramips/dts/mt7628an.dtsi
+++ b/target/linux/ramips/dts/mt7628an.dtsi
@@ -46,16 +46,9 @@
 		};
 
 		watchdog: watchdog@100 {
-			compatible = "ralink,mt7628an-wdt", "mediatek,mt7621-wdt";
-			reg = <0x100 0x30>;
-
-			clocks = <&sysc 6>;
-
-			resets = <&sysc 8>;
-			reset-names = "wdt";
-
-			interrupt-parent = <&intc>;
-			interrupts = <24>;
+			compatible = "mediatek,mt7621-wdt";
+			reg = <0x100 0x100>;
+			mediatek,sysctl = <&sysc>;
 		};
 
 		intc: intc@200 {
diff --git a/target/linux/ramips/patches-5.15/009-v6.3-01-watchdog-mt7621-wdt-avoid-static-global-declarations.patch b/target/linux/ramips/patches-5.15/009-v6.3-01-watchdog-mt7621-wdt-avoid-static-global-declarations.patch
new file mode 100644
index 0000000000..e06d5621e1
--- /dev/null
+++ b/target/linux/ramips/patches-5.15/009-v6.3-01-watchdog-mt7621-wdt-avoid-static-global-declarations.patch
@@ -0,0 +1,213 @@
+From 783c7cb4659b53b5e1b809dac5e8cdf250145919 Mon Sep 17 00:00:00 2001
+From: Sergio Paracuellos <sergio.paracuellos@gmail.com>
+Date: Tue, 14 Feb 2023 11:39:35 +0100
+Subject: [PATCH 1/2] watchdog: mt7621-wdt: avoid static global declarations
+
+Instead of using static global definitions in driver code, refactor code
+introducing a new watchdog driver data structure and use it along the
+code.
+
+Reviewed-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
+Link: https://lore.kernel.org/r/20230214103936.1061078-5-sergio.paracuellos@gmail.com
+[groeck: unsigned -> unsigned int]
+Signed-off-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
+---
+ drivers/watchdog/mt7621_wdt.c | 102 +++++++++++++++++++++++++++---------------
+ 1 file changed, 65 insertions(+), 37 deletions(-)
+
+--- a/drivers/watchdog/mt7621_wdt.c
++++ b/drivers/watchdog/mt7621_wdt.c
+@@ -31,8 +31,11 @@
+ #define TMR1CTL_RESTART			BIT(9)
+ #define TMR1CTL_PRESCALE_SHIFT		16
+ 
+-static void __iomem *mt7621_wdt_base;
+-static struct reset_control *mt7621_wdt_reset;
++struct mt7621_wdt_data {
++	void __iomem *base;
++	struct reset_control *rst;
++	struct watchdog_device wdt;
++};
+ 
+ static bool nowayout = WATCHDOG_NOWAYOUT;
+ module_param(nowayout, bool, 0);
+@@ -40,27 +43,31 @@ MODULE_PARM_DESC(nowayout,
+ 		 "Watchdog cannot be stopped once started (default="
+ 		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+ 
+-static inline void rt_wdt_w32(unsigned reg, u32 val)
++static inline void rt_wdt_w32(void __iomem *base, unsigned int reg, u32 val)
+ {
+-	iowrite32(val, mt7621_wdt_base + reg);
++	iowrite32(val, base + reg);
+ }
+ 
+-static inline u32 rt_wdt_r32(unsigned reg)
++static inline u32 rt_wdt_r32(void __iomem *base, unsigned int reg)
+ {
+-	return ioread32(mt7621_wdt_base + reg);
++	return ioread32(base + reg);
+ }
+ 
+ static int mt7621_wdt_ping(struct watchdog_device *w)
+ {
+-	rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART);
++	struct mt7621_wdt_data *drvdata = watchdog_get_drvdata(w);
++
++	rt_wdt_w32(drvdata->base, TIMER_REG_TMRSTAT, TMR1CTL_RESTART);
+ 
+ 	return 0;
+ }
+ 
+ static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
+ {
++	struct mt7621_wdt_data *drvdata = watchdog_get_drvdata(w);
++
+ 	w->timeout = t;
+-	rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000);
++	rt_wdt_w32(drvdata->base, TIMER_REG_TMR1LOAD, t * 1000);
+ 	mt7621_wdt_ping(w);
+ 
+ 	return 0;
+@@ -68,29 +75,31 @@ static int mt7621_wdt_set_timeout(struct
+ 
+ static int mt7621_wdt_start(struct watchdog_device *w)
+ {
++	struct mt7621_wdt_data *drvdata = watchdog_get_drvdata(w);
+ 	u32 t;
+ 
+ 	/* set the prescaler to 1ms == 1000us */
+-	rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT);
++	rt_wdt_w32(drvdata->base, TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT);
+ 
+ 	mt7621_wdt_set_timeout(w, w->timeout);
+ 
+-	t = rt_wdt_r32(TIMER_REG_TMR1CTL);
++	t = rt_wdt_r32(drvdata->base, TIMER_REG_TMR1CTL);
+ 	t |= TMR1CTL_ENABLE;
+-	rt_wdt_w32(TIMER_REG_TMR1CTL, t);
++	rt_wdt_w32(drvdata->base, TIMER_REG_TMR1CTL, t);
+ 
+ 	return 0;
+ }
+ 
+ static int mt7621_wdt_stop(struct watchdog_device *w)
+ {
++	struct mt7621_wdt_data *drvdata = watchdog_get_drvdata(w);
+ 	u32 t;
+ 
+ 	mt7621_wdt_ping(w);
+ 
+-	t = rt_wdt_r32(TIMER_REG_TMR1CTL);
++	t = rt_wdt_r32(drvdata->base, TIMER_REG_TMR1CTL);
+ 	t &= ~TMR1CTL_ENABLE;
+-	rt_wdt_w32(TIMER_REG_TMR1CTL, t);
++	rt_wdt_w32(drvdata->base, TIMER_REG_TMR1CTL, t);
+ 
+ 	return 0;
+ }
+@@ -105,7 +114,9 @@ static int mt7621_wdt_bootcause(void)
+ 
+ static int mt7621_wdt_is_running(struct watchdog_device *w)
+ {
+-	return !!(rt_wdt_r32(TIMER_REG_TMR1CTL) & TMR1CTL_ENABLE);
++	struct mt7621_wdt_data *drvdata = watchdog_get_drvdata(w);
++
++	return !!(rt_wdt_r32(drvdata->base, TIMER_REG_TMR1CTL) & TMR1CTL_ENABLE);
+ }
+ 
+ static const struct watchdog_info mt7621_wdt_info = {
+@@ -121,30 +132,39 @@ static const struct watchdog_ops mt7621_
+ 	.set_timeout = mt7621_wdt_set_timeout,
+ };
+ 
+-static struct watchdog_device mt7621_wdt_dev = {
+-	.info = &mt7621_wdt_info,
+-	.ops = &mt7621_wdt_ops,
+-	.min_timeout = 1,
+-	.max_timeout = 0xfffful / 1000,
+-};
+-
+ static int mt7621_wdt_probe(struct platform_device *pdev)
+ {
+ 	struct device *dev = &pdev->dev;
+-	mt7621_wdt_base = devm_platform_ioremap_resource(pdev, 0);
+-	if (IS_ERR(mt7621_wdt_base))
+-		return PTR_ERR(mt7621_wdt_base);
+-
+-	mt7621_wdt_reset = devm_reset_control_get_exclusive(dev, NULL);
+-	if (!IS_ERR(mt7621_wdt_reset))
+-		reset_control_deassert(mt7621_wdt_reset);
+-
+-	mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause();
+-
+-	watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout,
+-			      dev);
+-	watchdog_set_nowayout(&mt7621_wdt_dev, nowayout);
+-	if (mt7621_wdt_is_running(&mt7621_wdt_dev)) {
++	struct watchdog_device *mt7621_wdt;
++	struct mt7621_wdt_data *drvdata;
++	int err;
++
++	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
++	if (!drvdata)
++		return -ENOMEM;
++
++	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
++	if (IS_ERR(drvdata->base))
++		return PTR_ERR(drvdata->base);
++
++	drvdata->rst = devm_reset_control_get_exclusive(dev, NULL);
++	if (!IS_ERR(drvdata->rst))
++		reset_control_deassert(drvdata->rst);
++
++	mt7621_wdt = &drvdata->wdt;
++	mt7621_wdt->info = &mt7621_wdt_info;
++	mt7621_wdt->ops = &mt7621_wdt_ops;
++	mt7621_wdt->min_timeout = 1;
++	mt7621_wdt->max_timeout = 0xfffful / 1000;
++	mt7621_wdt->parent = dev;
++
++	mt7621_wdt->bootstatus = mt7621_wdt_bootcause();
++
++	watchdog_init_timeout(mt7621_wdt, mt7621_wdt->max_timeout, dev);
++	watchdog_set_nowayout(mt7621_wdt, nowayout);
++	watchdog_set_drvdata(mt7621_wdt, drvdata);
++
++	if (mt7621_wdt_is_running(mt7621_wdt)) {
+ 		/*
+ 		 * Make sure to apply timeout from watchdog core, taking
+ 		 * the prescaler of this driver here into account (the
+@@ -154,17 +174,25 @@ static int mt7621_wdt_probe(struct platf
+ 		 * we first disable the watchdog, set the new prescaler
+ 		 * and timeout, and then re-enable the watchdog.
+ 		 */
+-		mt7621_wdt_stop(&mt7621_wdt_dev);
+-		mt7621_wdt_start(&mt7621_wdt_dev);
+-		set_bit(WDOG_HW_RUNNING, &mt7621_wdt_dev.status);
++		mt7621_wdt_stop(mt7621_wdt);
++		mt7621_wdt_start(mt7621_wdt);
++		set_bit(WDOG_HW_RUNNING, &mt7621_wdt->status);
+ 	}
+ 
+-	return devm_watchdog_register_device(dev, &mt7621_wdt_dev);
++	err = devm_watchdog_register_device(dev, &drvdata->wdt);
++	if (err)
++		return err;
++
++	platform_set_drvdata(pdev, drvdata);
++
++	return 0;
+ }
+ 
+ static void mt7621_wdt_shutdown(struct platform_device *pdev)
+ {
+-	mt7621_wdt_stop(&mt7621_wdt_dev);
++	struct mt7621_wdt_data *drvdata = platform_get_drvdata(pdev);
++
++	mt7621_wdt_stop(&drvdata->wdt);
+ }
+ 
+ static const struct of_device_id mt7621_wdt_match[] = {
diff --git a/target/linux/ramips/patches-5.15/009-v6.3-02-watchdog-mt7621-wdt-avoid-ralink-architecture-depend.patch b/target/linux/ramips/patches-5.15/009-v6.3-02-watchdog-mt7621-wdt-avoid-ralink-architecture-depend.patch
new file mode 100644
index 0000000000..8e6265404b
--- /dev/null
+++ b/target/linux/ramips/patches-5.15/009-v6.3-02-watchdog-mt7621-wdt-avoid-ralink-architecture-depend.patch
@@ -0,0 +1,104 @@
+From ff8ec4ac39ad413b580d611dbf68e1d8a82eba56 Mon Sep 17 00:00:00 2001
+From: Sergio Paracuellos <sergio.paracuellos@gmail.com>
+Date: Tue, 14 Feb 2023 11:39:36 +0100
+Subject: [PATCH 2/2] 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>
+---
+ drivers/watchdog/Kconfig      |  4 +++-
+ drivers/watchdog/mt7621_wdt.c | 22 +++++++++++++++++-----
+ 2 files changed, 20 insertions(+), 6 deletions(-)
+
+--- a/drivers/watchdog/Kconfig
++++ b/drivers/watchdog/Kconfig
+@@ -1799,7 +1799,9 @@ config RALINK_WDT
+ 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.
+ 
+--- 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 watchd
+ 	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_
+ 
+ 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 platf
+ 	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 platf
+ 	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);