Re: [PATCHv9 02/20] thermal: introduce device tree parser

Wei Ni
2014-01-07T02:48:02Z

Hi, Eduardo
Will you consider my comments :)

Thanks.
Wei.

On 12/31/2013 06:17 PM, Wei Ni wrote:
> On 11/13/2013 03:46 AM, Eduardo Valentin wrote:
>> This patch introduces a device tree bindings for
>> describing the hardware thermal behavior and limits.
>> Also a parser to read and interpret the data and feed
>> it in the thermal framework is presented.
>>
>> This patch introduces a thermal data parser for device
>> tree. The parsed data is used to build thermal zones
>> and thermal binding parameters. The output data
>> can then be used to deploy thermal policies.
>>
>> This patch adds also documentation regarding this
>> API and how to define tree nodes to use
>> this infrastructure.
>>
>> Note that, in order to be able to have control
>> on the sensor registration on the DT thermal zone,
>> it was required to allow changing the thermal zone
>> .get_temp callback. For this reason, this patch
>> also removes the 'const' modifier from the .ops
>> field of thermal zone devices.
>>
>> ...
>> +
>> +static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
>> + enum thermal_trend *trend)
>> +{
>> + struct __thermal_zone *data = tz->devdata;
>> + long dev_trend;
>> + int r;
>> +
>> + if (!data->get_trend)
>> + return -EINVAL;
>> +
>> + r = data->get_trend(data->sensor_data, &dev_trend);
> I think the ->get_trend should be defined as:
> .get_trend(*dev, int, *long)
> so that the "trip" can be passed into it, otherwise the "trip" can't be
> used.
> And the dev_trend should be returned as THERMAL_TREND_XXX directly.
> because the THERM_TREND_xx is more than three states.
>
> The code may be something like:
> r = data->get_trend(data->sensor_data, trip, &dev_trend);
> if (r)
> return r;
> *trend = dev_trend;
> return 0;
>> + if (r)
>> + return r;
>> +
>> + /* TODO: These intervals might have some thresholds, but in core code */
>> + if (dev_trend > 0)
>> + *trend = THERMAL_TREND_RAISING;
>> + else if (dev_trend < 0)
>> + *trend = THERMAL_TREND_DROPPING;
>> + else
>> + *trend = THERMAL_TREND_STABLE;
>> +
>> + return 0;
>> +}
>> +
>> .....
>> +
>> +/*** sensor API ***/
>> +
>> +static struct thermal_zone_device *
>> +thermal_zone_of_add_sensor(struct device_node *zone,
>> + struct device_node *sensor, void *data,
>> + int (*get_temp)(void *, long *),
>> + int (*get_trend)(void *, long *))
>> +{
>> + struct thermal_zone_device *tzd;
>> + struct __thermal_zone *tz;
>> +
>> + tzd = thermal_zone_get_zone_by_name(zone->name);
> I think we could get the thermal zone by node,
> something like:
> thermal_zone_get_zone_by_node(zone);
> so that it can get unique zone.
>
> I think we can add a member "struct device_node *np" in the
> thermal_zone_device,
> and set it after you call thermal_zone_device_register successfully.
> Then add following codes:
> thermal_zone_get_zone_by_node(struct device_node *node)
> {
> struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-ENODEV);
> bool found = false;
>
> if (!node)
> return ERR_PTR(-EINVAL);
>
> mutex_lock(&thermal_list_lock);
> list_for_each_entry(pos, &thermal_tz_list, node)
> if (node == pos->np) {
> ref = pos;
> found = true;
> break;
> }
> mutex_unlock(&thermal_list_lock);
>
> return ref;
> }
>
> Thanks.
> Wei.
>> + if (IS_ERR(tzd))
>> + return ERR_PTR(-EPROBE_DEFER);
>> +
>> + tz = tzd->devdata;
>> +
>> + mutex_lock(&tzd->lock);
>> + tz->get_temp = get_temp;
>> + tz->get_trend = get_trend;
>> + tz->sensor_data = data;
>> +
>> + tzd->ops->get_temp = of_thermal_get_temp;
>> + tzd->ops->get_trend = of_thermal_get_trend;
>> + mutex_unlock(&tzd->lock);
>> +
>> + return tzd;
>> +}
>> +
>>
>

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