hwmon: (pwm-fan) Add optional regulator support

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

1 files changed, 42 insertions, 1 deletions

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 2c944825026f..167221c7628a 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)
+                        return PTR_ERR(ctx->reg_en);
+
+                ctx->reg_en = NULL;
+        } 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 @@ err_pwm_disable:
         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;
 }
 
@@ -307,6 +332,14 @@ static int pwm_fan_suspend(struct device *dev)
                 pwm_disable(ctx->pwm);
         }
 
+        if (ctx->reg_en) {
+                ret = regulator_disable(ctx->reg_en);
+                if (ret) {
+                        dev_err(dev, "Failed to disable fan supply: %d\n", ret);
+                        return ret;
+                }
+        }
+
         return 0;
 }
 
@@ -317,6 +350,14 @@ 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);
+                        return ret;
+                }
+        }
+
         if (ctx->pwm_value == 0)
                 return 0;