[PATCH v3 0/4] watchdog: mt7621-wdt: avoid globals and arch dependencies

[PATCH v3 0/4] watchdog: mt7621-wdt: avoid globals and arch dependencies

[Sergio Paracuellos]

Hi all,

This series make an update in the MT7621 SoC's watchdog driver code. This
SoC already provides a system controller node to access reset status
register needed for the watchdog. Instead of using MIPS architecture
dependent operations in header 'asm/mach-ralink/ralink_regs.h' use
a phandle to the system controller node and use it through regmap APIs
from the code. Driver is also using some globals that are not needed at
all if a driver data structure is used along the code. Hence, add all
new needed stuff inside a new driver data structure. With this changes
driver can be properly compile tested.

Thanks in advance for reviewing this!

V1 of this series here [0].
V2 os thise series here [1].

Changes in v3:
    - rename phandler from 'ralink,sysctl' into 'mediatek,sysctl'.
    - Drop error message added in PATHC 3 that modifies functionality and we
      only want to maintain current functionaloty by now.

Changes in v2:
    - Remove no needed compatible 'syscon' from bindings.
    - Rewrite new syscon phandle description in bindings.
    - Remove 'syscon' from compatible in 'mt7621.dtsi'.
    - Split PATCH 3 into two different patches:
        - PATCH 3: removes static globals using a driver data structure.
        - PATCH 4: remove ralink architecture dependent includes and code.

Best regards,
    Sergio Paracuellos

[0]: https://lore.kernel.org/linux-watchdog/20230210065621.598120-1-sergio.paracuellos@gmail.com/T/#t
[1]: https://lore.kernel.org/linux-watchdog/20230210121735.639089-1-sergio.paracuellos@gmail.com/T/#t

Sergio Paracuellos (4):
  dt-bindings: watchdog: mt7621-wdt: add phandle to access system
    controller registers
  mips: dts: ralink: mt7621: add phandle to system controller node for
    watchdog
  watchdog: mt7621-wdt: avoid static global declarations
  watchdog: mt7621-wdt: avoid ralink architecture dependent code

 .../watchdog/mediatek,mt7621-wdt.yaml         |   7 ++
 arch/mips/boot/dts/ralink/mt7621.dtsi         |   1 +
 drivers/watchdog/Kconfig                      |   2 +
 drivers/watchdog/mt7621_wdt.c                 | 119 ++++++++++++------
 4 files changed, 88 insertions(+), 41 deletions(-)

-- 
2.25.1

[PATCH v3 1/4] dt-bindings: watchdog: mt7621-wdt: add phandle to access system controller registers

[Sergio Paracuellos]

MT7621 SoC provides a system controller node for accessing to some registers.
Add a phandle in this node to avoid using MIPS related arch operations and
includes in watchdog driver code.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
---
 .../devicetree/bindings/watchdog/mediatek,mt7621-wdt.yaml  | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/watchdog/mediatek,mt7621-wdt.yaml b/Documentation/devicetree/bindings/watchdog/mediatek,mt7621-wdt.yaml
index b2b17fdf4..a668d0c2f 100644
--- a/Documentation/devicetree/bindings/watchdog/mediatek,mt7621-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/mediatek,mt7621-wdt.yaml
@@ -19,6 +19,12 @@ properties:
   reg:
     maxItems: 1
 
+  mediatek,sysctl:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      phandle to system controller 'sysc' syscon node which
+      controls system registers
+
 required:
   - compatible
   - reg
@@ -30,4 +36,5 @@ examples:
     watchdog@100 {
       compatible = "mediatek,mt7621-wdt";
       reg = <0x100 0x100>;
+      mediatek,sysctl = <&sysc>;
     };
-- 
2.25.1

[PATCH v3 2/4] mips: dts: ralink: mt7621: add phandle to system controller node for watchdog

[Sergio Paracuellos]

To allow to access system controller registers from watchdog driver code
add a phandle in the watchdog 'wdt' node. This avoid using arch dependent
operations in driver code.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
---
 arch/mips/boot/dts/ralink/mt7621.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/mips/boot/dts/ralink/mt7621.dtsi b/arch/mips/boot/dts/ralink/mt7621.dtsi
index 5ca40fd21..764916eaf 100644
--- a/arch/mips/boot/dts/ralink/mt7621.dtsi
+++ b/arch/mips/boot/dts/ralink/mt7621.dtsi
@@ -73,6 +73,7 @@ sysc: syscon@0 {
 		wdt: wdt@100 {
 			compatible = "mediatek,mt7621-wdt";
 			reg = <0x100 0x100>;
+			mediatek,sysctl = <&sysc>;
 		};
 
 		gpio: gpio@600 {
-- 
2.25.1

[PATCH v3 3/4] watchdog: mt7621-wdt: avoid static global declarations

[Sergio Paracuellos]

Instead of using static global definitions in driver code, refactor code
introducing a new watchdog driver data structure and use it along the
code.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
---
 drivers/watchdog/mt7621_wdt.c | 102 ++++++++++++++++++++++------------
 1 file changed, 65 insertions(+), 37 deletions(-)

diff --git a/drivers/watchdog/mt7621_wdt.c b/drivers/watchdog/mt7621_wdt.c
index a8aa3522c..40fb2c9ba 100644
--- 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 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 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 watchdog_device *w, unsigned int t)
 
 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_wdt_ops = {
 	.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);
+	struct watchdog_device *mt7621_wdt;
+	struct mt7621_wdt_data *drvdata;
+	int err;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
 
-	mt7621_wdt_reset = devm_reset_control_get_exclusive(dev, NULL);
-	if (!IS_ERR(mt7621_wdt_reset))
-		reset_control_deassert(mt7621_wdt_reset);
+	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(drvdata->base))
+		return PTR_ERR(drvdata->base);
 
-	mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause();
+	drvdata->rst = devm_reset_control_get_exclusive(dev, NULL);
+	if (!IS_ERR(drvdata->rst))
+		reset_control_deassert(drvdata->rst);
 
-	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)) {
+	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 platform_device *pdev)
 		 * 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[] = {
-- 
2.25.1

[PATCH v3 4/4] watchdog: mt7621-wdt: avoid ralink architecture dependent code

[Sergio Paracuellos]

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>
---
 drivers/watchdog/Kconfig      |  2 ++
 drivers/watchdog/mt7621_wdt.c | 19 ++++++++++++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index b64bc49c7..0759de670 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1865,6 +1865,8 @@ config GXP_WATCHDOG
 config MT7621_WDT
 	tristate "Mediatek SoC watchdog"
 	select WATCHDOG_CORE
+	select REGMAP_MMIO
+	select MFD_SYSCON
 	depends on SOC_MT7620 || SOC_MT7621
 	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 40fb2c9ba..9ed07c187 100644
--- 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 +148,10 @@ 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))
+		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 +167,7 @@ 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);
-- 
2.25.1

Re: [PATCH v3 2/4] mips: dts: ralink: mt7621: add phandle to system controller node for watchdog

[Arınç ÜNAL]

Could you also change the node name to watchdog@100? make dtbs_check 
points it out:

wdt@100: $nodename:0: 'wdt@100' does not match '^watchdog(@.*|-[0-9a-f])?$'

Thanks.
Arınç

On 10.02.2023 20:38, Sergio Paracuellos wrote:
> To allow to access system controller registers from watchdog driver code
> add a phandle in the watchdog 'wdt' node. This avoid using arch dependent
> operations in driver code.
> 
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> ---
>   arch/mips/boot/dts/ralink/mt7621.dtsi | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/mips/boot/dts/ralink/mt7621.dtsi b/arch/mips/boot/dts/ralink/mt7621.dtsi
> index 5ca40fd21..764916eaf 100644
> --- a/arch/mips/boot/dts/ralink/mt7621.dtsi
> +++ b/arch/mips/boot/dts/ralink/mt7621.dtsi
> @@ -73,6 +73,7 @@ sysc: syscon@0 {
>   		wdt: wdt@100 {
>   			compatible = "mediatek,mt7621-wdt";
>   			reg = <0x100 0x100>;
> +			mediatek,sysctl = <&sysc>;
>   		};
>   
>   		gpio: gpio@600 {

Re: [PATCH v3 3/4] watchdog: mt7621-wdt: avoid static global declarations

[Guenter Roeck]

On Fri, Feb 10, 2023 at 06:38:40PM +0100, Sergio Paracuellos wrote:
> Instead of using static global definitions in driver code, refactor code
> introducing a new watchdog driver data structure and use it along the
> code.
> 
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/watchdog/mt7621_wdt.c | 102 ++++++++++++++++++++++------------
>  1 file changed, 65 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/watchdog/mt7621_wdt.c b/drivers/watchdog/mt7621_wdt.c
> index a8aa3522c..40fb2c9ba 100644
> --- 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 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 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 watchdog_device *w, unsigned int t)
>  
>  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_wdt_ops = {
>  	.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);
> +	struct watchdog_device *mt7621_wdt;
> +	struct mt7621_wdt_data *drvdata;
> +	int err;
> +
> +	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> +	if (!drvdata)
> +		return -ENOMEM;
>  
> -	mt7621_wdt_reset = devm_reset_control_get_exclusive(dev, NULL);
> -	if (!IS_ERR(mt7621_wdt_reset))
> -		reset_control_deassert(mt7621_wdt_reset);
> +	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(drvdata->base))
> +		return PTR_ERR(drvdata->base);
>  
> -	mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause();
> +	drvdata->rst = devm_reset_control_get_exclusive(dev, NULL);
> +	if (!IS_ERR(drvdata->rst))
> +		reset_control_deassert(drvdata->rst);
>  
> -	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)) {
> +	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 platform_device *pdev)
>  		 * 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[] = {
> -- 
> 2.25.1
> 

Re: [PATCH v3 4/4] watchdog: mt7621-wdt: avoid ralink architecture dependent code

[Guenter Roeck]

On Fri, Feb 10, 2023 at 06:38:41PM +0100, Sergio Paracuellos wrote:
> 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>

> ---
>  drivers/watchdog/Kconfig      |  2 ++
>  drivers/watchdog/mt7621_wdt.c | 19 ++++++++++++++-----
>  2 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index b64bc49c7..0759de670 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1865,6 +1865,8 @@ config GXP_WATCHDOG
>  config MT7621_WDT
>  	tristate "Mediatek SoC watchdog"
>  	select WATCHDOG_CORE
> +	select REGMAP_MMIO
> +	select MFD_SYSCON
>  	depends on SOC_MT7620 || SOC_MT7621
>  	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 40fb2c9ba..9ed07c187 100644
> --- 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 +148,10 @@ 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))
> +		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 +167,7 @@ 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);
> -- 
> 2.25.1
> 

Re: [PATCH v3 2/4] mips: dts: ralink: mt7621: add phandle to system controller node for watchdog

[Sergio Paracuellos]

Hi Arınç,

On Fri, Feb 10, 2023 at 6:47 PM Arınç ÜNAL <arinc.unal@arinc9.com> wrote:
>
> Could you also change the node name to watchdog@100? make dtbs_check
> points it out:
>
> wdt@100: $nodename:0: 'wdt@100' does not match '^watchdog(@.*|-[0-9a-f])?$'

Sure, let me add a small patch fixing this warning in the series.

>
> Thanks.
> Arınç

Best regards,
    Sergio Paracuellos

>
> On 10.02.2023 20:38, Sergio Paracuellos wrote:
> > To allow to access system controller registers from watchdog driver code
> > add a phandle in the watchdog 'wdt' node. This avoid using arch dependent
> > operations in driver code.
> >
> > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> > ---
> >   arch/mips/boot/dts/ralink/mt7621.dtsi | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/mips/boot/dts/ralink/mt7621.dtsi b/arch/mips/boot/dts/ralink/mt7621.dtsi
> > index 5ca40fd21..764916eaf 100644
> > --- a/arch/mips/boot/dts/ralink/mt7621.dtsi
> > +++ b/arch/mips/boot/dts/ralink/mt7621.dtsi
> > @@ -73,6 +73,7 @@ sysc: syscon@0 {
> >               wdt: wdt@100 {
> >                       compatible = "mediatek,mt7621-wdt";
> >                       reg = <0x100 0x100>;
> > +                     mediatek,sysctl = <&sysc>;
> >               };
> >
> >               gpio: gpio@600 {