Re: [PATCH v2 4/4] hwmon: (adt7470) Use standard update_interval property

Chris Packham
2021-08-29T21:09:19Z

On 28/08/21 9:29 am, Guenter Roeck wrote:
> On Thu, Aug 26, 2021 at 02:41:21PM +1200, Chris Packham wrote:
>> Instead of the non-standard auto_update_interval make use of the
>> update_interval property that is supported by the hwmon core.
>>
>> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
>> ---
>>
>> Notes:
>> I kind of anticipate a NAK on this because it affects the ABI. But I figured
>> I'd run it past the ML to see if moving towards the hwmon core is worth the hit
>> in ABI compatibility.
>>
> I personally don't mind (most likely no one is using it anyway), but let's
> wait until after the upcoming commit window closes to give people time to
> complain.

I know of one application using this sysfs entry. But it's our in-house
environmental monitoring code so if this gets merged I'll just update it
to use the new path.

One thought I had was we could do both. i.e. have an entry that conforms
to the hwmon core and a backwards compatible entry that just aliases the
new path.

>
> Guenter
>
>> Changes in v2:
>> - none
>>
>> drivers/hwmon/adt7470.c | 64 +++++++++++++++++++++++++----------------
>> 1 file changed, 39 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
>> index db19a52b13de..7afbd1e4721e 100644
>> --- a/drivers/hwmon/adt7470.c
>> +++ b/drivers/hwmon/adt7470.c
>> @@ -469,35 +469,37 @@ static struct adt7470_data *adt7470_update_device(struct device *dev)
>> return err < 0 ? ERR_PTR(err) : data;
>> }
>>
>> -static ssize_t auto_update_interval_show(struct device *dev,
>> - struct device_attribute *devattr,
>> - char *buf)
>> -{
>> - struct adt7470_data *data = adt7470_update_device(dev);
>> -
>> - if (IS_ERR(data))
>> - return PTR_ERR(data);
>> -
>> - return sprintf(buf, "%d\n", data->auto_update_interval);
>> -}
>> -
>> -static ssize_t auto_update_interval_store(struct device *dev,
>> - struct device_attribute *devattr,
>> - const char *buf, size_t count)
>> +static int adt7470_chip_read(struct device *dev, u32 attr, long *val)
>> {
>> struct adt7470_data *data = dev_get_drvdata(dev);
>> - long temp;
>>
>> - if (kstrtol(buf, 10, &temp))
>> - return -EINVAL;
>> + switch (attr) {
>> + case hwmon_chip_update_interval:
>> + *val = data->auto_update_interval;
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>>
>> - temp = clamp_val(temp, 0, 60000);
>> + return 0;
>> +}
>>
>> - mutex_lock(&data->lock);
>> - data->auto_update_interval = temp;
>> - mutex_unlock(&data->lock);
>> +static int adt7470_chip_write(struct device *dev, u32 attr, long val)
>> +{
>> + struct adt7470_data *data = dev_get_drvdata(dev);
>>
>> - return count;
>> + switch (attr) {
>> + case hwmon_chip_update_interval:
>> + val = clamp_val(val, 0, 60000);
>> + mutex_lock(&data->lock);
>> + data->auto_update_interval = val;
>> + mutex_unlock(&data->lock);
>> + break;
>> + default:
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + return 0;
>> }
>>
>> static ssize_t num_temp_sensors_show(struct device *dev,
>> @@ -1034,7 +1036,6 @@ static ssize_t pwm_auto_temp_store(struct device *dev,
>>
>> static DEVICE_ATTR_RW(alarm_mask);
>> static DEVICE_ATTR_RW(num_temp_sensors);
>> -static DEVICE_ATTR_RW(auto_update_interval);
>>
>> static SENSOR_DEVICE_ATTR_RW(force_pwm_max, force_pwm_max, 0);
>>
>> @@ -1066,7 +1067,6 @@ static SENSOR_DEVICE_ATTR_RW(pwm4_auto_channels_temp, pwm_auto_temp, 3);
>> static struct attribute *adt7470_attrs[] = {
>> &dev_attr_alarm_mask.attr,
>> &dev_attr_num_temp_sensors.attr,
>> - &dev_attr_auto_update_interval.attr,
>> &sensor_dev_attr_force_pwm_max.dev_attr.attr,
>> &sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
>> &sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
>> @@ -1097,6 +1097,8 @@ static int adt7470_read(struct device *dev, enum hwmon_sensor_types type, u32 at
>> int channel, long *val)
>> {
>> switch (type) {
>> + case hwmon_chip:
>> + return adt7470_chip_read(dev, attr, val);
>> case hwmon_temp:
>> return adt7470_temp_read(dev, attr, channel, val);
>> case hwmon_fan:
>> @@ -1112,6 +1114,8 @@ static int adt7470_write(struct device *dev, enum hwmon_sensor_types type, u32 a
>> int channel, long val)
>> {
>> switch (type) {
>> + case hwmon_chip:
>> + return adt7470_chip_write(dev, attr, val);
>> case hwmon_temp:
>> return adt7470_temp_write(dev, attr, channel, val);
>> case hwmon_fan:
>> @@ -1129,6 +1133,15 @@ static umode_t adt7470_is_visible(const void *_data, enum hwmon_sensor_types typ
>> umode_t mode = 0;
>>
>> switch (type) {
>> + case hwmon_chip:
>> + switch (attr) {
>> + case hwmon_chip_update_interval:
>> + mode = 0644;
>> + break;
>> + default:
>> + break;
>> + }
>> + break;
>> case hwmon_temp:
>> switch (attr) {
>> case hwmon_temp:
>> @@ -1187,6 +1200,7 @@ static const struct hwmon_ops adt7470_hwmon_ops = {
>> };
>>
>> static const struct hwmon_channel_info *adt7470_info[] = {
>> + HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
>> HWMON_CHANNEL_INFO(temp,
>> HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,
>> HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_ALARM,