hwmon: (aspeed-pwm-tacho) On read failure return -ETIMEDOUT

When the controller fails to provide an RPM reading within the alloted
time; the driver returns -ETIMEDOUT and no file contents.

Signed-off-by: Patrick Venture <venture@google.com>
Fixes: 2d7a548a3e ("drivers: hwmon: Support for ASPEED PWM/Fan tach")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Patrick Venture 2017-05-30 12:42:01 -07:00 committed by Guenter Roeck
parent 08fd5e76c2
commit 7ed1c5e5dd
1 changed files with 9 additions and 3 deletions

View File

@ -7,6 +7,7 @@
*/
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/delay.h>
#include <linux/hwmon.h>
@ -494,7 +495,7 @@ static u32 aspeed_get_fan_tach_ch_measure_period(struct aspeed_pwm_tacho_data
return clk / (clk_unit * div_h * div_l * tacho_div * tacho_unit);
}
static u32 aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
u8 fan_tach_ch)
{
u32 raw_data, tach_div, clk_source, sec, val;
@ -510,6 +511,9 @@ static u32 aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
msleep(sec);
regmap_read(priv->regmap, ASPEED_PTCR_RESULT, &val);
if (!(val & RESULT_STATUS_MASK))
return -ETIMEDOUT;
raw_data = val & RESULT_VALUE_MASK;
tach_div = priv->type_fan_tach_clock_division[type];
tach_div = 0x4 << (tach_div * 2);
@ -561,12 +565,14 @@ static ssize_t show_rpm(struct device *dev, struct device_attribute *attr,
{
struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
int index = sensor_attr->index;
u32 rpm;
int rpm;
struct aspeed_pwm_tacho_data *priv = dev_get_drvdata(dev);
rpm = aspeed_get_fan_tach_ch_rpm(priv, index);
if (rpm < 0)
return rpm;
return sprintf(buf, "%u\n", rpm);
return sprintf(buf, "%d\n", rpm);
}
static umode_t pwm_is_visible(struct kobject *kobj,