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

Eduardo Valentin
2014-01-07T11:17:11Z

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On 06-01-2014 22:48, Wei Ni wrote:
> Hi, Eduardo
> Will you consider my comments :)

By now Wei, it is better if you start a new thread, by sending a patch
on top of it, as this thread has been already merged by Rui.

>
> 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;
>>> +}
>>> +
>>>
>>
>
>
>

--
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin

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