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

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Message-Id: <1548781631-5736-2-git-send-email-stefan.wahren@i2se.com>
Date:   Tue, 29 Jan 2019 18:07:11 +0100
From:   Stefan Wahren <stefan.wahren@...e.com>
To:     Kamil Debski <kamil@...as.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Jean Delvare <jdelvare@...e.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>
Cc:     linux-hwmon@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Stefan Wahren <stefan.wahren@...e.com>
Subject: [PATCH 2/2] 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@...e.com>
---
 drivers/hwmon/pwm-fan.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 2c94482..9e0591e 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;
@@ -244,6 +246,23 @@ static int pwm_fan_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan");
+	if (!IS_ERR(ctx->reg_en)) {
+		ret = regulator_enable(ctx->reg_en);
+		if (ret)
+			dev_err(&pdev->dev,
+				"Failed to enable fan supply: %d\n", ret);
+	} else {
+		switch (PTR_ERR(ctx->reg_en)) {
+		case -ENODEV:
+		case -ENOSYS:
+			ctx->reg_en = NULL;
+			break;
+		default:
+			return PTR_ERR(ctx->reg_en);
+		}
+	}
+
 	hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
 						       ctx, pwm_fan_groups);
 	if (IS_ERR(hwmon)) {
@@ -287,6 +306,10 @@ 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 +322,12 @@ 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 +346,12 @@ 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