This small series implements the optional regulator support for the
pwm-fan driver.
Changes in V2:
- address Guenter's comments:
- handle error case first
- drop ENOSYS handling
- implement more consistent bail out handling
- enable regulator before setup PWM
- make sure we disable regulator if probe fails
Stefan Wahren (2):
dt-bindings: hwmon: Add optional regulator support to pwm-fan
hwmon: pwm-fan: Add optional regulator support
.../devicetree/bindings/hwmon/pwm-fan.txt | 3 ++
drivers/hwmon/pwm-fan.c | 39 +++++++++++++++++++++-
2 files changed, 41 insertions(+), 1 deletion(-)
--
2.7.4
This adds an optional regulator support (e.g. switchable supply) to the
pwm fan binding.
Signed-off-by: Stefan Wahren <[email protected]>
---
Documentation/devicetree/bindings/hwmon/pwm-fan.txt | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
index c6d5332..49ca5d8 100644
--- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
+++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
@@ -6,6 +6,9 @@ Required properties:
- cooling-levels : PWM duty cycle values in a range from 0 to 255
which correspond to thermal cooling states
+Optional properties:
+- fan-supply : phandle to the regulator that provides power to the fan
+
Example:
fan0: pwm-fan {
compatible = "pwm-fan";
--
2.7.4
This adds optional regulator support to the pwm-fan driver. This is
necessary for pwm fans which are powered by a switchable supply.
Signed-off-by: Stefan Wahren <[email protected]>
---
drivers/hwmon/pwm-fan.c | 39 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 2c94482..344915c 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -23,6 +23,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
+#include <linux/regulator/consumer.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>
@@ -31,6 +32,7 @@
struct pwm_fan_ctx {
struct mutex lock;
struct pwm_device *pwm;
+ struct regulator *reg_en;
unsigned int pwm_value;
unsigned int pwm_fan_state;
unsigned int pwm_fan_max_state;
@@ -231,6 +233,21 @@ static int pwm_fan_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, ctx);
+ ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan");
+ if (IS_ERR(ctx->reg_en)) {
+ if (PTR_ERR(ctx->reg_en) == -ENODEV)
+ ctx->reg_en = NULL;
+ else
+ return PTR_ERR(ctx->reg_en);
+ } else {
+ ret = regulator_enable(ctx->reg_en);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to enable fan supply: %d\n", ret);
+ return ret;
+ }
+ }
+
ctx->pwm_value = MAX_PWM;
/* Set duty cycle to maximum allowed and enable PWM output */
@@ -241,7 +258,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
ret = pwm_apply_state(ctx->pwm, &state);
if (ret) {
dev_err(&pdev->dev, "Failed to configure PWM\n");
- return ret;
+ goto err_reg_disable;
}
hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
@@ -277,6 +294,10 @@ static int pwm_fan_probe(struct platform_device *pdev)
state.enabled = false;
pwm_apply_state(ctx->pwm, &state);
+err_reg_disable:
+ if (ctx->reg_en)
+ regulator_disable(ctx->reg_en);
+
return ret;
}
@@ -287,6 +308,10 @@ static int pwm_fan_remove(struct platform_device *pdev)
thermal_cooling_device_unregister(ctx->cdev);
if (ctx->pwm_value)
pwm_disable(ctx->pwm);
+
+ if (ctx->reg_en)
+ regulator_disable(ctx->reg_en);
+
return 0;
}
@@ -299,6 +324,12 @@ static int pwm_fan_suspend(struct device *dev)
pwm_get_args(ctx->pwm, &args);
+ if (ctx->reg_en) {
+ ret = regulator_disable(ctx->reg_en);
+ if (ret)
+ dev_err(dev, "Failed to disable fan supply: %d\n", ret);
+ }
+
if (ctx->pwm_value) {
ret = pwm_config(ctx->pwm, 0, args.period);
if (ret < 0)
@@ -317,6 +348,12 @@ static int pwm_fan_resume(struct device *dev)
unsigned long duty;
int ret;
+ if (ctx->reg_en) {
+ ret = regulator_enable(ctx->reg_en);
+ if (ret)
+ dev_err(dev, "Failed to enable fan supply: %d\n", ret);
+ }
+
if (ctx->pwm_value == 0)
return 0;
--
2.7.4
On Thu, Feb 07, 2019 at 05:38:00PM +0100, Stefan Wahren wrote:
> This adds optional regulator support to the pwm-fan driver. This is
> necessary for pwm fans which are powered by a switchable supply.
>
> Signed-off-by: Stefan Wahren <[email protected]>
> ---
> drivers/hwmon/pwm-fan.c | 39 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 2c94482..344915c 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -23,6 +23,7 @@
> #include <linux/of.h>
> #include <linux/platform_device.h>
> #include <linux/pwm.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/sysfs.h>
> #include <linux/thermal.h>
>
> @@ -31,6 +32,7 @@
> struct pwm_fan_ctx {
> struct mutex lock;
> struct pwm_device *pwm;
> + struct regulator *reg_en;
> unsigned int pwm_value;
> unsigned int pwm_fan_state;
> unsigned int pwm_fan_max_state;
> @@ -231,6 +233,21 @@ static int pwm_fan_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, ctx);
>
> + ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan");
> + if (IS_ERR(ctx->reg_en)) {
> + if (PTR_ERR(ctx->reg_en) == -ENODEV)
> + ctx->reg_en = NULL;
> + else
> + return PTR_ERR(ctx->reg_en);
if PTR_ERR(ctx->reg_en) != -ENODEV)
return PTR_ERR(ctx->reg_en);
ctx->reg_en = NULL;
would be a bit easier to read and avoid an else.
> + } else {
> + ret = regulator_enable(ctx->reg_en);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "Failed to enable fan supply: %d\n", ret);
> + return ret;
> + }
> + }
> +
> ctx->pwm_value = MAX_PWM;
>
> /* Set duty cycle to maximum allowed and enable PWM output */
> @@ -241,7 +258,7 @@ static int pwm_fan_probe(struct platform_device *pdev)
> ret = pwm_apply_state(ctx->pwm, &state);
> if (ret) {
> dev_err(&pdev->dev, "Failed to configure PWM\n");
> - return ret;
> + goto err_reg_disable;
> }
>
> hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
> @@ -277,6 +294,10 @@ static int pwm_fan_probe(struct platform_device *pdev)
> state.enabled = false;
> pwm_apply_state(ctx->pwm, &state);
>
> +err_reg_disable:
> + if (ctx->reg_en)
> + regulator_disable(ctx->reg_en);
> +
> return ret;
> }
>
> @@ -287,6 +308,10 @@ static int pwm_fan_remove(struct platform_device *pdev)
> thermal_cooling_device_unregister(ctx->cdev);
> if (ctx->pwm_value)
> pwm_disable(ctx->pwm);
> +
> + if (ctx->reg_en)
> + regulator_disable(ctx->reg_en);
> +
> return 0;
> }
>
> @@ -299,6 +324,12 @@ static int pwm_fan_suspend(struct device *dev)
>
> pwm_get_args(ctx->pwm, &args);
>
> + if (ctx->reg_en) {
> + ret = regulator_disable(ctx->reg_en);
> + if (ret)
> + dev_err(dev, "Failed to disable fan supply: %d\n", ret);
This is a bit weird. The error is returned to the caller, but only if
ctx->pwm_value is 0. Otherwise it is ignored. This warrants an explanation
(and some selling) if it is on purpose.
> + }
> +
> if (ctx->pwm_value) {
> ret = pwm_config(ctx->pwm, 0, args.period);
> if (ret < 0)
> @@ -317,6 +348,12 @@ static int pwm_fan_resume(struct device *dev)
> unsigned long duty;
> int ret;
>
> + if (ctx->reg_en) {
> + ret = regulator_enable(ctx->reg_en);
> + if (ret)
> + dev_err(dev, "Failed to enable fan supply: %d\n", ret);
Does it really make sense here to ignore this error ? After all,
the fan will likely not work if that error really happens. Doesn't
that count as resume failure ?
> + }
> +
> if (ctx->pwm_value == 0)
> return 0;
>
> --
> 2.7.4
>
On Thu, 7 Feb 2019 17:37:59 +0100, Stefan Wahren wrote:
> This adds an optional regulator support (e.g. switchable supply) to the
> pwm fan binding.
>
> Signed-off-by: Stefan Wahren <[email protected]>
> ---
> Documentation/devicetree/bindings/hwmon/pwm-fan.txt | 3 +++
> 1 file changed, 3 insertions(+)
>
Reviewed-by: Rob Herring <[email protected]>