From: Neil Armstrong <narmstrong@baylibre.com>
To: Zhang Ning <zhangn1985@qq.com>, linux-amlogic@lists.infradead.org
Subject: Re: [PATCH] Ask a question about why can't use GPIOAO: GPIO_TEST_N
Date: Mon, 18 Jul 2022 10:20:36 +0200 [thread overview]
Message-ID: <71e3e938-78fb-ed82-c5fb-81ba78550526@baylibre.com> (raw)
In-Reply-To: <tencent_CE3C171C6300ED12361ED2B813BF0D5A0608@qq.com>
Hi,
On 14/07/2022 04:07, Zhang Ning wrote:
> first this is not a code review, just ask a question.
>
> I started to enable MagicBox M16S, and sent patches for review.
>
> but leds are not enabled.
>
> I have tried, and found gpioao: GPIO_TEST_N can control led on off.
>
> thus I add it to dts:
>
> leds {
> compatible = "gpio-leds";
>
> led-white {
> color = <LED_COLOR_ID_WHITE>;
> function = LED_FUNCTION_POWER;
> gpios = <&gpio_ao GPIO_TEST_N GPIO_ACTIVE_HIGH>;
> default-state = "keep";
> };
> };
>
> but failed with error -22.
>
> and simply change GPIO_TEST_N to GPIOAO_2, no error.
>
> thus find pinctrl driver doesn't allow to use this gpio.
>
> why?
The TEST_N pinctrl needs a SMC call to set the pin GPIO direction, so it needs
more code to control the pin.
I did an experimental support a few years ago:
https://github.com/superna9999/linux/commits/amlogic/v4.19/gpio-test-n
I would need to be refreshed to work on 5.20.
Neil
>
> Signed-off-by: Zhang Ning <zhangn1985@qq.com>
> ---
> drivers/pinctrl/meson/pinctrl-meson-gxl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/meson/pinctrl-meson-gxl.c b/drivers/pinctrl/meson/pinctrl-meson-gxl.c
> index 51408996255b..fb5fa88b30c7 100644
> --- a/drivers/pinctrl/meson/pinctrl-meson-gxl.c
> +++ b/drivers/pinctrl/meson/pinctrl-meson-gxl.c
> @@ -820,7 +820,7 @@ static struct meson_bank meson_gxl_periphs_banks[] = {
>
> static struct meson_bank meson_gxl_aobus_banks[] = {
> /* name first last irq pullen pull dir out in */
> - BANK("AO", GPIOAO_0, GPIOAO_9, 0, 9, 0, 16, 0, 0, 0, 0, 0, 16, 1, 0),
> + BANK("AO", GPIOAO_0, GPIO_TEST_N, 0, 9, 0, 16, 0, 0, 0, 0, 0, 16, 1, 0),
> };
>
> static struct meson_pinctrl_data meson_gxl_periphs_pinctrl_data = {
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prev parent reply other threads:[~2022-07-18 8:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-14 2:07 Zhang Ning
2022-07-18 8:20 ` Neil Armstrong [this message]
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