Message-ID: <936e828c-15e0-5223-7daa-94b2fafc2602@amlogic.com>
Date:   Mon, 10 Jan 2022 16:55:21 +0800
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Subject: Re: [PATCH] tty: serial: meson: Request the register region in
 meson_uart_probe()
Content-Language: en-US
To:     <linux-serial@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-amlogic@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>
CC:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>
References: <20220110082616.13474-1-yu.tu@amlogic.com>
 <20220110082616.13474-5-yu.tu@amlogic.com>
From:   Yu Tu <yu.tu@amlogic.com>
In-Reply-To: <20220110082616.13474-5-yu.tu@amlogic.com>
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Hi All,
	I'm really sorry for sending the wrong specified file. Please ignore 
the email. I will resend V4.

On 2022/1/10 16:26, Yu Tu wrote:
> This simplifies resetting the UART controller during probe and will make
> it easier to integrate the common clock code which will require the
> registers at probe time as well.
> 
> Signed-off-by: Yu Tu <yu.tu@amlogic.com>
> ---
>   drivers/tty/serial/meson_uart.c | 24 ++++++------------------
>   1 file changed, 6 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
> index c9a37602ffd0..99efe62a1507 100644
> --- a/drivers/tty/serial/meson_uart.c
> +++ b/drivers/tty/serial/meson_uart.c
> @@ -397,24 +397,11 @@ static int meson_uart_verify_port(struct uart_port *port,
>   
>   static void meson_uart_release_port(struct uart_port *port)
>   {
> -	devm_iounmap(port->dev, port->membase);
> -	port->membase = NULL;
> -	devm_release_mem_region(port->dev, port->mapbase, port->mapsize);
> +	/* nothing to do */
>   }
>   
>   static int meson_uart_request_port(struct uart_port *port)
>   {
> -	if (!devm_request_mem_region(port->dev, port->mapbase, port->mapsize,
> -				     dev_name(port->dev))) {
> -		dev_err(port->dev, "Memory region busy\n");
> -		return -EBUSY;
> -	}
> -
> -	port->membase = devm_ioremap(port->dev, port->mapbase,
> -					     port->mapsize);
> -	if (!port->membase)
> -		return -ENOMEM;
> -
>   	return 0;
>   }
>   
> @@ -728,6 +715,10 @@ static int meson_uart_probe(struct platform_device *pdev)
>   	if (!port)
>   		return -ENOMEM;
>   
> +	port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
> +	if (IS_ERR(port->membase))
> +		return PTR_ERR(port->membase);
> +
>   	ret = meson_uart_probe_clocks(pdev, port);
>   	if (ret)
>   		return ret;
> @@ -749,10 +740,7 @@ static int meson_uart_probe(struct platform_device *pdev)
>   	platform_set_drvdata(pdev, port);
>   
>   	/* reset port before registering (and possibly registering console) */
> -	if (meson_uart_request_port(port) >= 0) {
> -		meson_uart_reset(port);
> -		meson_uart_release_port(port);
> -	}
> +	meson_uart_reset(port);
>   
>   	ret = uart_add_one_port(&meson_uart_driver, port);
>   	if (ret)
> 
> base-commit: b3a9e3b9622ae10064826dccb4f7a52bd88c7407
> prerequisite-patch-id: 97a514f3447511cb204179ce03ae99dc1d5902d9