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References: <20231228125805.661725-1-tudor.ambarus@linaro.org> <20231228125805.661725-7-tudor.ambarus@linaro.org>
In-Reply-To: <20231228125805.661725-7-tudor.ambarus@linaro.org>
From: Peter Griffin <peter.griffin@linaro.org>
Date: Mon, 8 Jan 2024 14:34:08 +0000
Message-ID: <CADrjBPpkBe4FsTHMOnQ-RLBjDCFM_QW8QZ0uVn35aX_9uiuo1A@mail.gmail.com>
Subject: Re: [PATCH v2 06/12] tty: serial: samsung: add gs101 earlycon support
To: Tudor Ambarus <tudor.ambarus@linaro.org>
Cc: robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, 
	mturquette@baylibre.com, sboyd@kernel.org, conor+dt@kernel.org, 
	andi.shyti@kernel.org, alim.akhtar@samsung.com, gregkh@linuxfoundation.org, 
	jirislaby@kernel.org, s.nawrocki@samsung.com, tomasz.figa@gmail.com, 
	cw00.choi@samsung.com, arnd@arndb.de, semen.protsenko@linaro.org, 
	andre.draszik@linaro.org, saravanak@google.com, willmcvicker@google.com, 
	linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, 
	linux-clk@vger.kernel.org, devicetree@vger.kernel.org, 
	linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, 
	linux-serial@vger.kernel.org, kernel-team@android.com
Content-Type: text/plain; charset="UTF-8"

Hi Tudor,

On Thu, 28 Dec 2023 at 12:58, Tudor Ambarus <tudor.ambarus@linaro.org> wrote:
>
> The entire bus (PERIC) on which the GS101 serial resides only allows
> 32-bit register accesses. The reg-io-width dt property is disallowed
> for the "google,gs101-uart" compatible and instead the iotype is
> inferred from the compatible. Always set UPIO_MEM32 iotype for the
> gs101 earlycon.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

That's a nice addition to avoid folks shooting themselves in the foot
when enabling earlycon.

Reviewed-by: Peter Griffin <peter.griffin@linaro.org>


> ---
> v2: update commit message
>
>  drivers/tty/serial/samsung_tty.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index 938127179acf..2fbaaf0e756b 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -2812,6 +2812,17 @@ OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
>  OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
>                         s5pv210_early_console_setup);
>
> +static int __init gs101_early_console_setup(struct earlycon_device *device,
> +                                           const char *opt)
> +{
> +       /* gs101 always expects MMIO32 register accesses. */
> +       device->port.iotype = UPIO_MEM32;
> +
> +       return s5pv210_early_console_setup(device, opt);
> +}
> +
> +OF_EARLYCON_DECLARE(gs101, "google,gs101-uart", gs101_early_console_setup);
> +
>  /* Apple S5L */
>  static int __init apple_s5l_early_console_setup(struct earlycon_device *device,
>                                                 const char *opt)
> --
> 2.43.0.472.g3155946c3a-goog
>