lkml.org 
[lkml]   [2013]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/6] serial: 8250_dw: add support for clocks property when using DeviceTree
Hi,

On Thu, Mar 07, 2013 at 11:14:15PM +0100, Maxime Ripard wrote:
> From: Emilio López <emilio@elopez.com.ar>
>
> This commit implements support for using the "clocks" DT property, instead
> of having to use clock-frequency.
>
> Signed-off-by: Emilio López <emilio@elopez.com.ar>
> ---
> drivers/tty/serial/8250/8250_dw.c | 32 ++++++++++++++++++++++----------
> 1 file changed, 22 insertions(+), 10 deletions(-)

<snip>

> @@ -137,8 +140,15 @@ static int dw8250_probe_of(struct uart_port *p)
> p->regshift = val;
>
> if (of_property_read_u32(np, "clock-frequency", &val)) {
> - dev_err(p->dev, "no clock-frequency property set\n");
> - return -EINVAL;
> + /* Get clk rate through clk driver if present */
> + data->clk = clk_get(p->dev, NULL);
> + if (IS_ERR(data->clk)) {
> + dev_err(p->dev, "clk or clock-frequency not defined\n");
> + return -EINVAL;
> + }
> +
> + clk_prepare_enable(data->clk);
> + val = clk_get_rate(data->clk);

Don't get the clk here..

> }
> p->uartclk = val;
>
> @@ -300,6 +310,12 @@ static int dw8250_probe(struct platform_device *pdev)

Get it here so it is then handled for also others besides DT users.
And prefer devm_clk_get(). Something like this:

...
uart.port.membase = ioremap(regs->start, resource_size(regs));
if (!uart.port.membase)
return -ENOMEM;

+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->clk = devm_clk_get(&pdev->dev, NULL);
+ clk_prepare_enable(data->clk);
+
uart.port.iotype = UPIO_MEM;
uart.port.serial_in = dw8250_serial_in;
uart.port.serial_out = dw8250_serial_out;
+ uart.port.private_data = data;
+ uart.port.uartclk = clk_get_rate(data->clk);

dw8250_setup_port(&uart);
...

Then in dw8250_probe_of() you need to use the "clock-frequency"
property only when p->uartclk is 0.

Thanks,

--
heikki
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2013-03-15 14:43    [W:0.061 / U:1.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site