On Fri, Jan 09, 2015 at 06:17:48PM +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. > > This also adds a comment stating that we do not know the actual formula > for calculating the temperature. > > Signed-off-by: Chen-Yu Tsai <w...@csie.org> > ---
CC [M] drivers/input/touchscreen/sun4i-ts.o drivers/input/touchscreen/sun4i-ts.c:208:15: error: variable ‘sun4i_ts_tz_ops’ has initializer but incomplete type static struct thermal_zone_of_device_ops sun4i_ts_tz_ops = { ^ drivers/input/touchscreen/sun4i-ts.c:209:2: error: unknown field ‘get_temp’ specified in initializer .get_temp = get_temp, ^ drivers/input/touchscreen/sun4i-ts.c:209:2: warning: excess elements in struct initializer [enabled by default] drivers/input/touchscreen/sun4i-ts.c:209:2: warning: (near initialization for ‘sun4i_ts_tz_ops’) [enabled by default] drivers/input/touchscreen/sun4i-ts.c: In function ‘sun4i_ts_probe’: drivers/input/touchscreen/sun4i-ts.c:331:8: warning: passing argument 4 of ‘thermal_zone_of_sensor_register’ from incompatible pointer type [enabled by default] &sun4i_ts_tz_ops); ^ In file included from drivers/input/touchscreen/sun4i-ts.c:37:0: include/linux/thermal.h:302:1: note: expected ‘int (*)(void *, long int *)’ but argument is of type ‘struct thermal_zone_of_device_ops *’ thermal_zone_of_sensor_register(struct device *dev, int id, ^ drivers/input/touchscreen/sun4i-ts.c:331:8: error: too few arguments to function ‘thermal_zone_of_sensor_register’ &sun4i_ts_tz_ops); ^ In file included from drivers/input/touchscreen/sun4i-ts.c:37:0: include/linux/thermal.h:302:1: note: declared here thermal_zone_of_sensor_register(struct device *dev, int id, ^ make[1]: *** [drivers/input/touchscreen/sun4i-ts.o] Error 1 make: *** [drivers/input/touchscreen/sun4i-ts.o] Error 2 > > changes since v1: > > - clean up thermal zone sensor when input device register fails > - unconditionally unregister thermal zone sensor on removal. > the unregister function checks the pointers passed in. > - add comment explaining the lack of documents for the temperature > calculation formula > > --- > .../bindings/input/touchscreen/sun4i.txt | 2 + > drivers/input/touchscreen/sun4i-ts.c | 47 > ++++++++++++++++++++++ > 2 files changed, 49 insertions(+) > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt > b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt > index aef57791f40b..a8405bab6c00 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 > > Optional properties: > - allwinner,ts-attached: boolean indicating that an actual touchscreen is > @@ -17,4 +18,5 @@ Example: > reg = <0x01c25000 0x100>; > interrupts = <29>; > allwinner,ts-attached; > + #thermal-sensor-cells = <0>; > }; > diff --git a/drivers/input/touchscreen/sun4i-ts.c > b/drivers/input/touchscreen/sun4i-ts.c > index 28a06749ae42..aac49db0b09d 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 +182,33 @@ 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; > + > + /* > + * The user manuals do not contain the formula for calculating > + * the temperature. The formula used here is from the AXP209, > + * which is designed by X-Powers, an affiliate of Allwinner: > + * > + * temperature = -144.7 + (value * 0.1) > + * > + * This should be replaced with the correct one if such information > + * becomes available. > + */ > + *temp = (ts->temp_data - 1447) * 100; > + > + 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) > { > @@ -189,6 +218,16 @@ static ssize_t show_temp(struct device *dev, struct > device_attribute *devattr, > if (ts->temp_data == -1) > return -EAGAIN; > > + /* > + * The user manuals do not contain the formula for calculating > + * the temperature. The formula used here is from the AXP209, > + * which is designed by X-Powers, an affiliate of Allwinner: > + * > + * temperature = -144.7 + (value * 0.1) > + * > + * This should be replaced with the correct one if such information > + * becomes available. > + */ > return sprintf(buf, "%d\n", (ts->temp_data - 1447) * 100); Why duplicate it here, instead of doing: static int sun4i_get_temp(struct sun4i_ts_data *ts, int *temp) { if (ts->temp_data == -1) return -EAGAIN; /* comment */ *temp = (ts->temp_data - 1447) * 100); return 0; } static int sun4i_tz_get_temp(void *data, long *temp) { return sun4i_get_temp(data, temp); } static ssize_t sun4i_show_temp(...) { error = sun4i_get_temp(ts, &temp); if (error) return error; return sprintf(buf, "%d\n", temp); } Also, thermal core seems to allow creating hwmon devices for thermal zones, can we use this feature? Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html