[PATCH V2 2/2] hwmon: pwm-fan: Add optional regulator support

Stefan Wahren
2019-02-07T16:39:16Z

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 <stefan.wahren@i2se.com>
---
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