On Thu, Jan 8, 2015 at 12:24 AM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
> Hi,
>
> On Tue, Jan 6, 2015 at 11:24 PM, Eduardo Valentin <edubezval@xxxxxxxxx> wrote:
>> Hello Chen-Yu,
>>
>>
>> On Tue, Jan 06, 2015 at 10:35:13AM +0800, Chen-Yu Tsai wrote:
>>> The touchscreen controller has a temperature sensor embedded in the SoC,
>>> which already has hwmon support in the driver.
>>>
>>> Add DT thermal zone support so we can use it with cpufreq for thermal
>>> throttling.
>>>
>>> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
>>> ---
>>> .../bindings/input/touchscreen/sun4i.txt | 1 +
>>> drivers/input/touchscreen/sun4i-ts.c | 27 ++++++++++++++++++++++
>>> 2 files changed, 28 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
>>> index aef57791f40b..7f1110adbd24 100644
>>> --- a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
>>> +++ b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
>>> @@ -5,6 +5,7 @@ Required properties:
>>> - compatible: "allwinner,sun4i-a10-ts"
>>> - reg: mmio address range of the chip
>>> - interrupts: interrupt to which the chip is connected
>>> + - #thermal-sensor-cells: shall be 0
>>>
>>
>> You may want to update your Example section too, below.
>> Example:
>>
>> rtp: rtp@01c25000 {
>> compatible = "allwinner,sun4i-a10-ts";
>> reg = <0x01c25000 0x100>;
>> interrupts = <29>;
>> allwinner,ts-attached;
>> #thermal-sensor-cells = <0>;
>> };
>
> Ok.
>
>>
>>
>>> Optional properties:
>>> - allwinner,ts-attached: boolean indicating that an actual touchscreen is
>>> diff --git a/drivers/input/touchscreen/sun4i-ts.c b/drivers/input/touchscreen/sun4i-ts.c
>>> index 28a06749ae42..b6e9043446d6 100644
>>> --- a/drivers/input/touchscreen/sun4i-ts.c
>>> +++ b/drivers/input/touchscreen/sun4i-ts.c
>>> @@ -34,6 +34,7 @@
>>>
>>> #include <linux/err.h>
>>> #include <linux/hwmon.h>
>>> +#include <linux/thermal.h>
>>> #include <linux/init.h>
>>> #include <linux/input.h>
>>> #include <linux/interrupt.h>
>>> @@ -107,6 +108,7 @@
>>> struct sun4i_ts_data {
>>> struct device *dev;
>>> struct input_dev *input;
>>> + struct thermal_zone_device *tz;
>>> void __iomem *base;
>>> unsigned int irq;
>>> bool ignore_fifo_data;
>>> @@ -180,6 +182,23 @@ static void sun4i_ts_close(struct input_dev *dev)
>>> writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
>>> }
>>>
>>> +static int get_temp(void *data, long *temp)
>>> +{
>>> + struct sun4i_ts_data *ts = data;
>>> +
>>> + /* No temp_data until the first irq */
>>> + if (ts->temp_data == -1)
>>> + return -EAGAIN;
>>> +
>>> + *temp = (ts->temp_data - 1447) * 100;
>>> +
>>
>> Care to explain the formula in a simple comment?
>
> This was just copied from the hwmon section. AFAIK there is no documentation
> for the formula. It was probably copied from Allwinner's SDK code.
>
> Hans? Do you remember where you got this?
So this is from the AXP209 datasheet. The Allwinner SoC datasheets don't
mention the formula to calculate the temperature. But since Allwinner
and X-powers are affiliated, it's possible they use the same formula.
http://comments.gmane.org/gmane.comp.hardware.netbook.arm.sunxi/3838
>>> + return 0;
>>> +}
>>> +
>>> +static struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
>>> + .get_temp = get_temp,
>>> +};
>>> +
>>> static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
>>> char *buf)
>>> {
>>> @@ -288,6 +307,11 @@ static int sun4i_ts_probe(struct platform_device *pdev)
>>> if (IS_ERR(hwmon))
>>> return PTR_ERR(hwmon);
>>>
>>> + ts->tz = thermal_zone_of_sensor_register(ts->dev, 0, ts,
>>> + &sun4i_ts_tz_ops);
>>> + if (IS_ERR(ts->tz))
>>> + ts->tz = NULL;
>>> +
>>> writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
>>>
>>> if (ts_attached) {
>>
>> here.. if input_register_device fails, you will keep an orphan thermal zone
>> registered in your system:
>>
>> error = input_register_device(ts->input);
>> if (error) {
>> writel(0, ts->base + TP_INT_FIFOC);
>
> Will add an unregister call here.
>
>
> Thanks for the review.
>
> ChenYu
>
>> return error;
>> }
>> ...
>>
>>
>>> @@ -310,6 +334,9 @@ static int sun4i_ts_remove(struct platform_device *pdev)
>>> if (ts->input)
>>> input_unregister_device(ts->input);
>>>
>>> + if (ts->tz)
>>> + thermal_zone_of_sensor_unregister(ts->dev, ts->tz);
>>> +
>>> /* Deactivate all IRQs */
>>> writel(0, ts->base + TP_INT_FIFOC);
>>>
>>> --
>>> 2.1.4
>>>
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