linux-kernel - [PATCH RESEND v6 4/6] hwmon: pwm-fan: Extract __set_pwm() function to only modify PWM duty cycle

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Date:	Wed, 04 Mar 2015 13:03:42 +0100
From:	Lukasz Majewski <l.majewski@...sung.com>
To:	Eduardo Valentin <edubezval@...il.com>,
	Kamil Debski <k.debski@...sung.com>,
	Jean Delvare <jdelvare@...e.de>,
	Guenter Roeck <linux@...ck-us.net>,
	Kukjin Kim <kgene@...nel.org>
Cc:	lm-sensors@...sensors.org,
	Linux PM list <linux-pm@...r.kernel.org>,
	"linux-samsung-soc@...r.kernel.org" 
	<linux-samsung-soc@...r.kernel.org>, devicetree@...r.kernel.org,
	Lukasz Majewski <l.majewski@...ess.pl>,
	Kukjin Kim <kgene.kim@...sung.com>,
	linux-kernel@...r.kernel.org,
	Sjoerd Simons <sjoerd.simons@...labora.co.uk>,
	Abhilash Kesavan <kesavan.abhilash@...il.com>,
	Abhilash Kesavan <a.kesavan@...sung.com>,
	Lukasz Majewski <l.majewski@...sung.com>
Subject: [PATCH RESEND v6 4/6] hwmon: pwm-fan: Extract __set_pwm() function to
 only modify PWM duty cycle

It was necessary to decouple code handling writing to sysfs from the one
responsible for setting PWM of the fan.
Due to that, new __set_pwm() method was extracted, which is responsible for
only setting new PWM duty cycle.

Signed-off-by: Lukasz Majewski <l.majewski@...sung.com>
---
Changes for v2:
- None
Changes for v3:
- The commit headline has been reedited.
Changes for v4:
- Protect "if (ctx->pwm_value == pwm)" with ctx lock
- Initialize ret with zero
Changes for v5:
- None
Changes for v6:
- None
---
 drivers/hwmon/pwm-fan.c | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 1991d903..bd42d39 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -33,20 +33,14 @@ struct pwm_fan_ctx {
 	unsigned char pwm_value;
 };
 
-static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
-		       const char *buf, size_t count)
+static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
 {
-	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
-	unsigned long pwm, duty;
-	ssize_t ret;
-
-	if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
-		return -EINVAL;
+	unsigned long duty;
+	int ret = 0;
 
 	mutex_lock(&ctx->lock);
-
 	if (ctx->pwm_value == pwm)
-		goto exit_set_pwm_no_change;
+		goto exit_set_pwm_err;
 
 	if (pwm == 0) {
 		pwm_disable(ctx->pwm);
@@ -66,13 +60,28 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
 
 exit_set_pwm:
 	ctx->pwm_value = pwm;
-exit_set_pwm_no_change:
-	ret = count;
 exit_set_pwm_err:
 	mutex_unlock(&ctx->lock);
 	return ret;
 }
 
+static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
+		       const char *buf, size_t count)
+{
+	struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
+	unsigned long pwm;
+	int ret;
+
+	if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
+		return -EINVAL;
+
+	ret = __set_pwm(ctx, pwm);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
 static ssize_t show_pwm(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
-- 
2.0.0.rc2

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