Re: [PATCH 1/2] ARM: dts: sun5i: Add touchscreen node to reference-design-tablet.dtsi

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 14-11-16 21:08, Maxime Ripard wrote:
> Hi,
>
> On Sun, Nov 13, 2016 at 08:22:02PM +0100, Hans de Goede wrote:
>> Just like on sun8i all sun5i tablets use the same interrupt and power
>> gpios for their touchscreens. I've checked all known a13 fex files and
>> only the UTOO P66 uses a different gpio for the interrupt.
>>
>> Add a touchscreen node to sun5i-reference-design-tablet.dtsi, which
>> fills in the necessary gpios to avoid duplication in the tablet dts files,
>> just like we do in sun8i-reference-design-tablet.dtsi.
>>
>> This will make future patches adding touchscreen nodes to a13 tablets
>> simpler.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  arch/arm/boot/dts/sun5i-a13-utoo-p66.dts           | 38 ++++++++--------------
>>  .../boot/dts/sun5i-reference-design-tablet.dtsi    | 25 ++++++++++++++
>>  2 files changed, 39 insertions(+), 24 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/sun5i-a13-utoo-p66.dts b/arch/arm/boot/dts/sun5i-a13-utoo-p66.dts
>> index a8b0bcc..3d7ff10 100644
>> --- a/arch/arm/boot/dts/sun5i-a13-utoo-p66.dts
>> +++ b/arch/arm/boot/dts/sun5i-a13-utoo-p66.dts
>> @@ -83,22 +83,6 @@
>>  	allwinner,pins = "PG3";
>>  };
>>
>> -&i2c1 {
>> -	icn8318: touchscreen@40 {
>> -		compatible = "chipone,icn8318";
>> -		reg = <0x40>;
>> -		interrupt-parent = <&pio>;
>> -		interrupts = <6 9 IRQ_TYPE_EDGE_FALLING>; /* EINT9 (PG9) */
>> -		pinctrl-names = "default";
>> -		pinctrl-0 = <&ts_wake_pin_p66>;
>> -		wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
>> -		touchscreen-size-x = <800>;
>> -		touchscreen-size-y = <480>;
>> -		touchscreen-inverted-x;
>> -		touchscreen-swapped-x-y;
>> -	};
>> -};
>> -
>>  &mmc2 {
>>  	pinctrl-names = "default";
>>  	pinctrl-0 = <&mmc2_pins_a>;
>> @@ -121,20 +105,26 @@
>>  		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>>  		allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
>>  	};
>> -
>> -	ts_wake_pin_p66: ts_wake_pin@0 {
>> -		allwinner,pins = "PB3";
>> -		allwinner,function = "gpio_out";
>> -		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>> -		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
>> -	};
>> -
>>  };
>>
>>  &reg_usb0_vbus {
>>  	gpio = <&pio 1 4 GPIO_ACTIVE_HIGH>; /* PB4 */
>>  };
>>
>> +&touchscreen {
>> +	compatible = "chipone,icn8318";
>> +	reg = <0x40>;
>> +	/* The P66 uses a different EINT then the reference design */
>> +	interrupts = <6 9 IRQ_TYPE_EDGE_FALLING>; /* EINT9 (PG9) */
>> +	/* The icn8318 binding expects wake-gpios instead of power-gpios */
>> +	wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
>> +	touchscreen-size-x = <800>;
>> +	touchscreen-size-y = <480>;
>> +	touchscreen-inverted-x;
>> +	touchscreen-swapped-x-y;
>> +	status = "okay";
>> +};
>> +
>>  &uart1 {
>>  	/* The P66 uses the uart pins as gpios */
>>  	status = "disabled";
>> diff --git a/arch/arm/boot/dts/sun5i-reference-design-tablet.dtsi b/arch/arm/boot/dts/sun5i-reference-design-tablet.dtsi
>> index 20cc940..7af488a 100644
>> --- a/arch/arm/boot/dts/sun5i-reference-design-tablet.dtsi
>> +++ b/arch/arm/boot/dts/sun5i-reference-design-tablet.dtsi
>> @@ -41,6 +41,7 @@
>>   */
>>  #include "sunxi-reference-design-tablet.dtsi"
>>
>> +#include <dt-bindings/interrupt-controller/irq.h>
>>  #include <dt-bindings/pwm/pwm.h>
>>
>>  / {
>> @@ -84,6 +85,23 @@
>>  };
>>
>>  &i2c1 {
>> +	/*
>> +	 * The gsl1680 is rated at 400KHz and it will not work reliable at
>> +	 * 100KHz, this has been confirmed on multiple different q8 tablets.
>> +	 * All other devices on this bus are also rated for 400KHz.
>> +	 */
>> +	clock-frequency = <400000>;
>> +
>> +	touchscreen: touchscreen {
>> +		interrupt-parent = <&pio>;
>> +		interrupts = <6 11 IRQ_TYPE_EDGE_FALLING>; /* EINT11 (PG11) */
>> +		pinctrl-names = "default";
>> +		pinctrl-0 = <&ts_power_pin>;
>> +		power-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
>> +		/* Tablet dts must provide reg and compatible */
>> +		status = "disabled";
>> +	};
>> +
>>  	pcf8563: rtc@51 {
>>  		compatible = "nxp,pcf8563";
>>  		reg = <0x51>;
>> @@ -125,6 +143,13 @@
>>  		allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
>>  	};
>>
>> +	ts_power_pin: ts_power_pin {
>> +		allwinner,pins = "PB3";
>> +		allwinner,function = "gpio_out";
>> +		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>> +		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
>> +	};
>> +
>
> For the next release, we'll switch to the generic pin mux properties
> ("pins" and "function"), and we actually implemented the fact that the
> drive and pull properties are optional, so you can drop them both.
>
> You'll need next + http://lists.infradead.org/pipermail/linux-arm-kernel/2016-November/467123.html

Ok, before I send a v2 first a question about this, for the touchscreen
case I actually need:

		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;

Because otherwise when the touchscreen controller is powered by a separate
regulator and that regulator is off, then it may draw just enough current
from its enable pin to be sort-of listening to the i2c bus and mess up
that bus.

So is this the default, or do we get the power-on default when not
specifying these? If it is the power-on default then we do need to
specify these, because AFAICT the power-on drive strength typically
is 20 mA.

Regards,

Hans