[PATCH v3 0/2] hwmon: Add reset support to aspeed-pwm-tach

[PATCH v3 0/2] hwmon: Add reset support to aspeed-pwm-tach

[Joel Stanley]

This series adds reset support so the ASPEED SoC can operate the
PWM/Tach unit without out of tree workarounds.

v3 drops the header sorting patch which is already applied, and adds
Rob's ack to the bindings change.

Joel Stanley (2):
  dt-bindings: hwmon: aspeed-pwm-tacho: Add reset node
  hwmon: (aspeed-pwm-tacho) Deassert reset in probe

 .../devicetree/bindings/hwmon/aspeed-pwm-tacho.txt | 14 +++++---------
 drivers/hwmon/aspeed-pwm-tacho.c                   | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+), 9 deletions(-)

-- 
2.15.1

[PATCH v3 1/2] dt-bindings: hwmon: aspeed-pwm-tacho: Add reset node

[Joel Stanley]

The device tree bindings are updated to document the resets phandle, and
the example is updated to match what is expected for both the reset and
clock phandle.

Note that the bindings should have always had the reset controller, as
the hardware is unusable without it.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 .../devicetree/bindings/hwmon/aspeed-pwm-tacho.txt         | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
index 367c8203213b..3ac02988a1a5 100644
--- a/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
+++ b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
@@ -22,8 +22,9 @@ Required properties for pwm-tacho node:
 - compatible : should be "aspeed,ast2400-pwm-tacho" for AST2400 and
 	       "aspeed,ast2500-pwm-tacho" for AST2500.
 
-- clocks : a fixed clock providing input clock frequency(PWM
-	   and Fan Tach clock)
+- clocks : phandle to clock provider with the clock number in the second cell
+
+- resets : phandle to reset controller with the reset number in the second cell
 
 fan subnode format:
 ===================
@@ -48,19 +49,14 @@ Required properties for each child node:
 
 Examples:
 
-pwm_tacho_fixed_clk: fixedclk {
-	compatible = "fixed-clock";
-	#clock-cells = <0>;
-	clock-frequency = <24000000>;
-};
-
 pwm_tacho: pwmtachocontroller@1e786000 {
 	#address-cells = <1>;
 	#size-cells = <1>;
 	#cooling-cells = <2>;
 	reg = <0x1E786000 0x1000>;
 	compatible = "aspeed,ast2500-pwm-tacho";
-	clocks = <&pwm_tacho_fixed_clk>;
+	clocks = <&syscon ASPEED_CLK_APB>;
+	resets = <&syscon ASPEED_RESET_PWM>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default>;
 
-- 
2.15.1

[PATCH v3 2/2] hwmon: (aspeed-pwm-tacho) Deassert reset in probe

[Joel Stanley]

The ASPEED SoC must deassert a reset in order to use the PWM/tach
peripheral.

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/hwmon/aspeed-pwm-tacho.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 63a95e23ca81..693a3d53cab5 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -19,6 +19,7 @@
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <linux/reset.h>
 #include <linux/sysfs.h>
 #include <linux/thermal.h>
 
@@ -181,6 +182,7 @@ struct aspeed_cooling_device {
 
 struct aspeed_pwm_tacho_data {
 	struct regmap *regmap;
+	struct reset_control *rst;
 	unsigned long clk_freq;
 	bool pwm_present[8];
 	bool fan_tach_present[16];
@@ -905,6 +907,13 @@ static int aspeed_create_fan(struct device *dev,
 	return 0;
 }
 
+static void aspeed_pwm_tacho_remove(void *data)
+{
+	struct aspeed_pwm_tacho_data *priv = data;
+
+	reset_control_assert(priv->rst);
+}
+
 static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -931,6 +940,19 @@ static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
 			&aspeed_pwm_tacho_regmap_config);
 	if (IS_ERR(priv->regmap))
 		return PTR_ERR(priv->regmap);
+
+	priv->rst = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(priv->rst)) {
+		dev_err(dev,
+			"missing or invalid reset controller device tree entry");
+		return PTR_ERR(priv->rst);
+	}
+	reset_control_deassert(priv->rst);
+
+	ret = devm_add_action_or_reset(dev, aspeed_pwm_tacho_remove, priv);
+	if (ret)
+		return ret;
+
 	regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE, 0);
 	regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE_EXT, 0);
 
-- 
2.15.1

Re: [v3,1/2] dt-bindings: hwmon: aspeed-pwm-tacho: Add reset node

[Guenter Roeck]

On Sat, Dec 23, 2017 at 11:35:27PM +1030, Joel wrote:
> The device tree bindings are updated to document the resets phandle, and
> the example is updated to match what is expected for both the reset and
> clock phandle.
> 
> Note that the bindings should have always had the reset controller, as
> the hardware is unusable without it.
> 
> Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Signed-off-by: Joel Stanley <joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org>

Applied to hwmon-next.

Thanks,
Guenter

> ---
>  .../devicetree/bindings/hwmon/aspeed-pwm-tacho.txt         | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
> index 367c8203213b..3ac02988a1a5 100644
> --- a/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
> +++ b/Documentation/devicetree/bindings/hwmon/aspeed-pwm-tacho.txt
> @@ -22,8 +22,9 @@ Required properties for pwm-tacho node:
>  - compatible : should be "aspeed,ast2400-pwm-tacho" for AST2400 and
>  	       "aspeed,ast2500-pwm-tacho" for AST2500.
>  
> -- clocks : a fixed clock providing input clock frequency(PWM
> -	   and Fan Tach clock)
> +- clocks : phandle to clock provider with the clock number in the second cell
> +
> +- resets : phandle to reset controller with the reset number in the second cell
>  
>  fan subnode format:
>  ===================
> @@ -48,19 +49,14 @@ Required properties for each child node:
>  
>  Examples:
>  
> -pwm_tacho_fixed_clk: fixedclk {
> -	compatible = "fixed-clock";
> -	#clock-cells = <0>;
> -	clock-frequency = <24000000>;
> -};
> -
>  pwm_tacho: pwmtachocontroller@1e786000 {
>  	#address-cells = <1>;
>  	#size-cells = <1>;
>  	#cooling-cells = <2>;
>  	reg = <0x1E786000 0x1000>;
>  	compatible = "aspeed,ast2500-pwm-tacho";
> -	clocks = <&pwm_tacho_fixed_clk>;
> +	clocks = <&syscon ASPEED_CLK_APB>;
> +	resets = <&syscon ASPEED_RESET_PWM>;
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default>;
>  
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Re: [v3,2/2] hwmon: (aspeed-pwm-tacho) Deassert reset in probe

[Guenter Roeck]

On Sat, Dec 23, 2017 at 11:35:28PM +1030, Joel wrote:
> The ASPEED SoC must deassert a reset in order to use the PWM/tach
> peripheral.
> 
> Signed-off-by: Joel Stanley <joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org>

Applied to hwmon-next.

Thanks,
Guenter

> ---
>  drivers/hwmon/aspeed-pwm-tacho.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
> index 63a95e23ca81..693a3d53cab5 100644
> --- a/drivers/hwmon/aspeed-pwm-tacho.c
> +++ b/drivers/hwmon/aspeed-pwm-tacho.c
> @@ -19,6 +19,7 @@
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/regmap.h>
> +#include <linux/reset.h>
>  #include <linux/sysfs.h>
>  #include <linux/thermal.h>
>  
> @@ -181,6 +182,7 @@ struct aspeed_cooling_device {
>  
>  struct aspeed_pwm_tacho_data {
>  	struct regmap *regmap;
> +	struct reset_control *rst;
>  	unsigned long clk_freq;
>  	bool pwm_present[8];
>  	bool fan_tach_present[16];
> @@ -905,6 +907,13 @@ static int aspeed_create_fan(struct device *dev,
>  	return 0;
>  }
>  
> +static void aspeed_pwm_tacho_remove(void *data)
> +{
> +	struct aspeed_pwm_tacho_data *priv = data;
> +
> +	reset_control_assert(priv->rst);
> +}
> +
>  static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> @@ -931,6 +940,19 @@ static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
>  			&aspeed_pwm_tacho_regmap_config);
>  	if (IS_ERR(priv->regmap))
>  		return PTR_ERR(priv->regmap);
> +
> +	priv->rst = devm_reset_control_get_exclusive(dev, NULL);
> +	if (IS_ERR(priv->rst)) {
> +		dev_err(dev,
> +			"missing or invalid reset controller device tree entry");
> +		return PTR_ERR(priv->rst);
> +	}
> +	reset_control_deassert(priv->rst);
> +
> +	ret = devm_add_action_or_reset(dev, aspeed_pwm_tacho_remove, priv);
> +	if (ret)
> +		return ret;
> +
>  	regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE, 0);
>  	regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE_EXT, 0);
>  
--
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