From 33a7ab91d509fa33b4bcd3ce0038cc80298050da Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 12 Dec 2013 08:05:32 +0100 Subject: [PATCH] hwmon: (w83l768ng) Fix fan speed control range The W83L786NG stores the fan speed on 4 bits while the sysfs interface uses a 0-255 range. Thus the driver should scale the user input down to map it to the device range, and scale up the value read from the device before presenting it to the user. The reserved register nibble should be left unchanged. Signed-off-by: Jean Delvare Cc: stable@vger.kernel.org Reviewed-by: Guenter Roeck --- drivers/hwmon/w83l786ng.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/w83l786ng.c b/drivers/hwmon/w83l786ng.c index f190219fa84d..6ed76ceb9270 100644 --- a/drivers/hwmon/w83l786ng.c +++ b/drivers/hwmon/w83l786ng.c @@ -481,9 +481,11 @@ store_pwm(struct device *dev, struct device_attribute *attr, if (err) return err; val = clamp_val(val, 0, 255); + val = DIV_ROUND_CLOSEST(val, 0x11); mutex_lock(&data->update_lock); - data->pwm[nr] = val; + data->pwm[nr] = val * 0x11; + val |= w83l786ng_read_value(client, W83L786NG_REG_PWM[nr]) & 0xf0; w83l786ng_write_value(client, W83L786NG_REG_PWM[nr], val); mutex_unlock(&data->update_lock); return count; @@ -777,8 +779,9 @@ static struct w83l786ng_data *w83l786ng_update_device(struct device *dev) ? 0 : 1; data->pwm_enable[i] = ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 3) + 1; - data->pwm[i] = w83l786ng_read_value(client, - W83L786NG_REG_PWM[i]); + data->pwm[i] = + (w83l786ng_read_value(client, W83L786NG_REG_PWM[i]) + & 0x0f) * 0x11; }