Messages in this thread Patch in this message | | | From | Rajkumar Rampelli <> | Subject | [PATCH V2 7/9] hwmon: pwm-fan: add sysfs node to read rpm of fan | Date | Wed, 21 Mar 2018 10:10:42 +0530 |
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Add fan device attribute fan1_input in pwm-fan driver to read speed of fan in rotations per minute.
Signed-off-by: Rajkumar Rampelli <rrajk@nvidia.com> ---
V2: Removed generic-pwm-tachometer driver and using pwm-fan driver as per suggestions to read fan speed. Added fan device attribute to report speed of fan in rpms through hwmon sysfs.
drivers/hwmon/pwm-fan.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 70cc0d1..8dda209 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -98,11 +98,34 @@ static ssize_t show_pwm(struct device *dev, return sprintf(buf, "%u\n", ctx->pwm_value); } +static ssize_t show_rpm(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct pwm_fan_ctx *ptt = dev_get_drvdata(dev); + struct pwm_device *pwm = ptt->pwm; + struct pwm_capture result; + unsigned int rpm = 0; + int ret; + + ret = pwm_capture(pwm, &result, 0); + if (ret < 0) { + pr_err("Failed to capture PWM: %d\n", ret); + return ret; + } + + if (result.period) + rpm = DIV_ROUND_CLOSEST_ULL(60ULL * NSEC_PER_SEC, + result.period); + + return sprintf(buf, "%u\n", rpm); +} static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm, 0); +static SENSOR_DEVICE_ATTR(fan1_input, 0444, show_rpm, NULL, 0); static struct attribute *pwm_fan_attrs[] = { &sensor_dev_attr_pwm1.dev_attr.attr, + &sensor_dev_attr_fan1_input.dev_attr.attr, NULL, }; -- 2.1.4
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