On Sat, Jan 10, 2015 at 2:07 AM, Eduardo Valentin <edubezval@xxxxxxxxx> wrote:
> On Thu, Jan 08, 2015 at 09:33:54PM +0800, Chen-Yu Tsai wrote:
>> 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
>
> Ok. We use in the thermal framework miliCelsius as the temperature
> unit. Can you make sure the resulting temperature is in miliCelsius?
Yes the result is in miliCelsius.
>>
>> >>> + 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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