[PATCH V2 3/3] serial/imx: parse from device tree support

[Grant Likely]

On Mon, Mar 7, 2011 at 6:06 AM, Jason Liu <jason.hui at linaro.org> wrote:
> Signed-off-by: Jason Liu <r64343 at freescale.com>
> Signed-off-by: Jeremy Kerr <jeremy.kerr at canonical.com>

Hi Jason,

comments below.

> ---
>  drivers/tty/serial/imx.c |   79 ++++++++++++++++++++++++++++++++++++++++------
>  1 files changed, 69 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index dfcf4b1..1ebca28 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -53,6 +53,9 @@
>  #include <mach/hardware.h>
>  #include <mach/imx-uart.h>
>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +
>  /* Register definitions */
>  #define URXD0 0x0  /* Receiver Register */
>  #define URTX0 0x40 /* Transmitter Register */
> @@ -1224,6 +1227,53 @@ static int serial_imx_resume(struct platform_device *dev)
>        return 0;
>  }
>
> +#ifdef CONFIG_OF
> +static int serial_imx_probe_dt(struct imx_port *sport,
> +               struct platform_device *pdev)
> +{
> +       struct device_node *node = pdev->dev.of_node;
> +       static int line;
> +
> +       if (!node)
> +               return -ENODEV;
> +
> +       if (of_get_property(node, "rts-cts", NULL))
> +               sport->have_rtscts = 1;
> +
> +       if (of_get_property(node, "irda", NULL))
> +               sport->use_irda = 1;

These properties need to be documented in
Documentation/devicetree/bindings/serial.  Also, for device specific
properties, it is considered good practice to prefix the property name
with the vendor name; so "fsl,rts-cts" and "fsl,irda".  Also, slightly
more descriptive property names would probably be helpful:
"fsl,has-rts-cts" and "fsl,irda-mode"

> +
> +       sport->port.line = line++;
> +
> +       return 0;
> +}
> +#else
> +static int serial_imx_probe_dt(struct imx_port *sport,
> +               struct platform_device *pdev)
> +{
> +       return -ENODEV;
> +}
> +#endif
> +
> +static int serial_imx_probe_pdata(struct imx_port *sport,
> +               struct platform_device *pdev)
> +{
> +       struct imxuart_platform_data *pdata = pdev->dev.platform_data;
> +
> +       if (!pdata)
> +               return 0;
> +
> +       if (pdata->flags & IMXUART_HAVE_RTSCTS)
> +               sport->have_rtscts = 1;
> +
> +#ifdef CONFIG_IRDA
> +       if (pdata->flags & IMXUART_IRDA)
> +               sport->use_irda = 1;
> +#endif
> +       sport->port.line = pdev->id;
> +
> +       return 0;
> +}
>  static int serial_imx_probe(struct platform_device *pdev)
>  {
>        struct imx_port *sport;
> @@ -1236,6 +1286,12 @@ static int serial_imx_probe(struct platform_device *pdev)
>        if (!sport)
>                return -ENOMEM;
>
> +       ret = serial_imx_probe_dt(sport, pdev);
> +       if (ret == -ENODEV)
> +               ret = serial_imx_probe_pdata(sport, pdev);
> +       if (ret)
> +               goto free;
> +
>        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>        if (!res) {
>                ret = -ENODEV;
> @@ -1260,7 +1316,6 @@ static int serial_imx_probe(struct platform_device *pdev)
>        sport->port.fifosize = 32;
>        sport->port.ops = &imx_pops;
>        sport->port.flags = UPF_BOOT_AUTOCONF;
> -       sport->port.line = pdev->id;
>        init_timer(&sport->timer);
>        sport->timer.function = imx_timeout;
>        sport->timer.data     = (unsigned long)sport;
> @@ -1274,17 +1329,13 @@ static int serial_imx_probe(struct platform_device *pdev)
>
>        sport->port.uartclk = clk_get_rate(sport->clk);
>
> -       imx_ports[pdev->id] = sport;
> +       if (imx_ports[sport->port.line]) {
> +               ret = -EBUSY;
> +               goto clkput;
> +       }
> +       imx_ports[sport->port.line] = sport;
>
>        pdata = pdev->dev.platform_data;
> -       if (pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
> -               sport->have_rtscts = 1;
> -
> -#ifdef CONFIG_IRDA
> -       if (pdata && (pdata->flags & IMXUART_IRDA))
> -               sport->use_irda = 1;
> -#endif
> -
>        if (pdata && pdata->init) {
>                ret = pdata->init(pdev);
>                if (ret)
> @@ -1336,6 +1387,11 @@ static int serial_imx_remove(struct platform_device *pdev)
>        return 0;
>  }
>
> +static struct of_device_id imx_uart_matches[] = {
> +       { .compatible = "imx-uart" },

Should be "fsl,imx51-uart".  It is always a good idea to specify the exact part.

> +       {},
> +};
> +
>  static struct platform_driver serial_imx_driver = {
>        .probe          = serial_imx_probe,
>        .remove         = serial_imx_remove,
> @@ -1345,6 +1401,9 @@ static struct platform_driver serial_imx_driver = {
>        .driver         = {
>                .name   = "imx-uart",
>                .owner  = THIS_MODULE,
> +#if defined(CONFIG_OF)
> +               .of_match_table = imx_uart_matches,
> +#endif
>        },
>  };
>
> --
> 1.7.0.4
>
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.