From mboxrd@z Thu Jan  1 00:00:00 1970
From: narmstrong@baylibre.com (Neil Armstrong)
Date: Thu, 23 Mar 2017 08:50:18 +0100
Subject: [PATCH 3/3] meson_uart: adds the core clock handling to the driver
In-Reply-To: <321e8a6f-0ec1-af24-8e9d-23000bf67806@gmail.com>
References: <321e8a6f-0ec1-af24-8e9d-23000bf67806@gmail.com>
Message-ID: <58D37E3A.3000205@baylibre.com>
To: linus-amlogic@lists.infradead.org
List-Id: linus-amlogic.lists.infradead.org



Le 22/03/2017 21:46, Helmut Klein a ?crit :
> the added lines are 1:1 ripped off amlogic's driver. They do what i want them to do.
> 
> I've hot no idea, if they are acceptable in that form.
> 
> 
> diff -Napur a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
> --- a/drivers/tty/serial/meson_uart.c    2017-03-09 21:09:47.000000000 +0100
> +++ b/drivers/tty/serial/meson_uart.c    2017-03-22 19:01:38.581613578 +0100
> @@ -600,6 +600,7 @@ static int meson_uart_probe(struct platf
>      struct resource *res_mem, *res_irq;
>      struct uart_port *port;
>      struct clk *clk;
> +    struct clk *core_clk;
>      int ret = 0;
> 
>      if (pdev->dev.of_node)
> @@ -625,6 +626,15 @@ static int meson_uart_probe(struct platf
>      if (!port)
>          return -ENOMEM;
> 
> +    core_clk = devm_clk_get(&pdev->dev, "core");
> +    if (!IS_ERR(core_clk)) {
> +        ret = clk_prepare_enable(core_clk);
> +        if(ret) {
> +            dev_err(&pdev->dev, "couldn't enable clkc\n");
> +            return ret;
> +        }
> +    }

it's correct, but the another way to go is :
if (IS_ERR(core_clk))
	core_clk = NULL;

ret = clk_prepare_enable(core_clk);
if(ret) {
    dev_err(&pdev->dev, "couldn't enable clkc\n");
    return ret;
}

clk_prepare_enable will accept NULL clk.

> +
>      clk = clk_get(&pdev->dev, NULL);
>      if (IS_ERR(clk))
>          return PTR_ERR(clk);
> 

Please also Cc the tty/serial maintainer here also.

Neil