[PATCH v4 6/8] hwmon: pwm-fan: Extract __set_pwm() function to only modify PWM duty cycle

Lukasz Majewski
2015-02-18T10:07:34Z

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@samsung.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
---
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