diff options
| author | Patrick Venture <venture@google.com> | 2017-05-30 12:42:01 -0700 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2017-05-30 15:15:40 -0700 |
| commit | 7ed1c5e5ddbb87aef9df7f8a8a714bcffe90f0eb (patch) | |
| tree | 3c99738ca60c33f8cf559cafde0ccabcec4a4afe /drivers/hwmon/aspeed-pwm-tacho.c | |
| parent | 08fd5e76c268b7a5353302825b6b63a6027ddd0a (diff) | |
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: 2d7a548a3eff ("drivers: hwmon: Support for ASPEED PWM/Fan tach")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/aspeed-pwm-tacho.c')
| -rw-r--r-- | drivers/hwmon/aspeed-pwm-tacho.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c index 48403a2115be..12b716b70ead 100644 --- a/drivers/hwmon/aspeed-pwm-tacho.c +++ b/drivers/hwmon/aspeed-pwm-tacho.c @@ -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, |