Hi, Biju,
On 01.07.2025 17:38, Biju Das wrote:
> Hi Geert,
>
>> -----Original Message-----
>> From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>> Sent: 01 July 2025 12:50
>> Subject: Re: [PATCH] arm64: dts: renesas: r9a09g047e57-smarc: Add gpio keys
>>
>> Hi Biju,
>>
>> On Tue, 1 Jul 2025 at 13:40, Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
>>>> From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> On Mon, 14 Apr 2025
>>>> at 17:38, Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
>>>>> RZ/G3E SMARC EVK has 3 user buttons called USER_SW1, USER_SW2 and
>>>>> USER_SW3. Add a DT node in device tree to instantiate the
>>>>> gpio-keys driver for these buttons.
>>>>>
>>>>> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
>>
>>>>> --- a/arch/arm64/boot/dts/renesas/renesas-smarc2.dtsi
>>>>> +++ b/arch/arm64/boot/dts/renesas/renesas-smarc2.dtsi
>>>>> @@ -12,8 +12,13 @@
>>>>> * SW_SDIO_M2E:
>>>>> * 0 - SMARC SDIO signal is connected to uSD1
>>>>> * 1 - SMARC SDIO signal is connected to M.2 Key E connector
>>>>> + *
>>>>> + * GPIO keys are enabled by default. Use PMOD_GPIO macros to
>>>>> + disable them
>>>>> + * if needed.
>>>>> */
>>>>>
>>>>> +#include <dt-bindings/input/input.h>
>>>>> +
>>>>> / {
>>>>> model = "Renesas RZ SMARC Carrier-II Board";
>>>>> compatible = "renesas,smarc2-evk"; @@ -27,6 +32,31 @@
>>>>> aliases {
>>>>> serial3 = &scif0;
>>>>> mmc1 = &sdhi1;
>>>>> };
>>>>> +
>>>>> + keys: keys {
>>>>> + compatible = "gpio-keys";
>>>>> +
>>>>> + key-1 {
>>>>> + interrupts-extended = <&pinctrl KEY_1_GPIO
>>>>> + IRQ_TYPE_EDGE_FALLING>;
>>>>
>>>> So you are using them as interrupts. Don't you need to configure pin
>>>> control for that (function 15 = IRQ14)?
>>>
>>> The same pin can be configured as TINT or IRQ15, currently it is configured as TINT IRQ.
>>> Is it ok?
>>
>> OK.
>>
>>>> Alternatively, can't you use them as gpios with interrupt facilities?
>>>
>>> interrupts-extended = <&pinctrl KEY_1_GPIO IRQ_TYPE_EDGE_FALLING>;
>>>
>>> The TINT IRQ will provide the same right? Am I missing anything here?
>>
>> When you use interrupts directly, the system will detect only key presses, and fake (timer-based) key
>> releases.
>> When you use GPIOs with interrupt-capability, the system can detect both key presses and releases.
>>
>> See also commit cab3511ea7a0b1fc ("ARM: dts: marzen: Add slide switches").
>
> As per [1], for GPIOs with interrupt-capability, IRQ controller needs to support both edges.
> But TINT supports Rising or Falling edge, but not both. So, we cannot use this.
If I clearly understand it, this has been solved on RZ/G3S SMARC Carrier-II
by defining these pins as gpio hogs:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/renesas/rzg3s-smarc.dtsi#n141
Thank you,
Claudiu
>
> That is the reason using interrupt directly.
>
> [1]
> https://elixir.bootlin.com/linux/v6.16-rc4/source/drivers/input/keyboard/gpio_keys.c#L980
>
>
> Cheers,
> Biju
