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From: Andy Shevchenko <andy.shevchenko@gmail.com>
Date: Wed, 5 Jun 2024 22:00:20 +0300
Message-ID: <CAHp75VfWZhmw00QP-ra4Zajn7LMvDW+NUT2fMx5kqeQ9eHLv5A@mail.gmail.com>
Subject: Re: [PATCH v11 6/8] platform: cznic: turris-omnia-mcu: Add support
 for MCU provided TRNG
To: =?UTF-8?B?TWFyZWsgQmVow7pu?= <kabel@kernel.org>, 
	Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Gregory CLEMENT <gregory.clement@bootlin.com>, Arnd Bergmann <arnd@arndb.de>, soc@kernel.org, 
	arm@kernel.org, Andy Shevchenko <andy@kernel.org>, Hans de Goede <hdegoede@redhat.com>, 
	=?UTF-8?Q?Ilpo_J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>, 
	Olivia Mackall <olivia@selenic.com>, Herbert Xu <herbert@gondor.apana.org.au>, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-crypto@vger.kernel.org
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On Wed, Jun 5, 2024 at 7:19=E2=80=AFPM Marek Beh=C3=BAn <kabel@kernel.org> =
wrote:
>
> Add support for true random number generator provided by the MCU.
> New Omnia boards come without the Atmel SHA204-A chip. Instead the
> crypto functionality is provided by new microcontroller, which has
> a TRNG peripheral.

+Cc: Bart for gpiochip_get_desc() usage.

...

> +#include <linux/bitfield.h>
> +#include <linux/completion.h>

+ errno.h

> +#include <linux/gpio/consumer.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/hw_random.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/minmax.h>
> +#include <linux/module.h>
> +#include <linux/string.h>

> +#include <linux/turris-omnia-mcu-interface.h>

As per other patches.

> +#include <linux/types.h>
> +
> +#include "turris-omnia-mcu.h"

...

> +       irq_idx =3D omnia_int_to_gpio_idx[__bf_shf(OMNIA_INT_TRNG)];
> +       irq =3D gpiod_to_irq(gpiochip_get_desc(&mcu->gc, irq_idx));
> +       if (irq < 0)
> +               return dev_err_probe(dev, irq, "Cannot get TRNG IRQ\n");

Okay, it's a bit more complicated than that. The gpiochip_get_desc()
shouldn't be used. Bart, what can you suggest to do here? Opencoding
it doesn't sound to me a (fully) correct approach in a long term.

--
With Best Regards,
Andy Shevchenko