[PATCH v4 2/2] serial: mxs-auart: Allow device tree probing

[Subodh Nijsure]

If one were to try run console on one of the /dev/ttyAPP* ports, as is 
the case for hardware I am working with, console output wouldn't show up 
without the following diff:

Let me know if should send formal patch or we can include it as part of v5?

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index ca3d25e..2ced332 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -761,7 +761,7 @@ static int __devinit mxs_auart_probe(struct 
platform_device *pdev)

         platform_set_drvdata(pdev, s);

-       auart_port[pdev->id] = s;
+       auart_port[s->port.line] = s;

         mxs_auart_reset(&s->port)

-Subodh

On 06/18/2012 06:06 AM, Fabio Estevam wrote:
> Allow device tree probing.
>
> Cc: Grant Likely<grant.likely at secretlab.ca>
> Cc: Rob Herring<rob.herring at calxeda.com>
> Cc: Alan Cox<alan at linux.intel.com>
> Cc:<linux-serial at vger.kernel.org>
> Signed-off-by: Fabio Estevam<fabio.estevam at freescale.com>
> ---
> Changes since v3:
> - Remove unneeded mxs_auart_devtype
> Changes since v2:
> - Change compatible string
> - Add aliases information in bindings doc
> - Remove unneeded mxs_auart_probe_pdev function
> - Remove "ifdef CONFIG_OF"
> - Remove of_match_ptr wrapper
> Changes since v1:
> - Merged patches 3 and 5 from v1 into this one
>   .../bindings/tty/serial/fsl-mxs-auart.txt          |   27 +++++++++++++
>   drivers/tty/serial/mxs-auart.c                     |   40 +++++++++++++++++++-
>   2 files changed, 66 insertions(+), 1 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
>
> diff --git a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
> new file mode 100644
> index 0000000..2ee903f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
> @@ -0,0 +1,27 @@
> +* Freescale MXS Application UART (AUART)
> +
> +Required properties:
> +- compatible : Should be "fsl,<soc>-auart". The supported SoCs include
> +  imx23 and imx28.
> +- reg : Address and length of the register set for the device
> +- interrupts : Should contain the auart interrupt numbers
> +
> +Example:
> +auart0: serial at 8006a000 {
> +	compatible = "fsl,imx28-auart", "fsl,imx23-auart";
> +	reg =<0x8006a000 0x2000>;
> +	interrupts =<112 70 71>;
> +};
> +
> +Note: Each auart port should have an alias correctly numbered in "aliases"
> +node.
> +
> +Example:
> +
> +aliases {
> +	serial0 =&auart0;
> +	serial1 =&auart1;
> +	serial2 =&auart2;
> +	serial3 =&auart3;
> +	serial4 =&auart4;
> +};
> diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
> index ec56d83..103087d 100644
> --- a/drivers/tty/serial/mxs-auart.c
> +++ b/drivers/tty/serial/mxs-auart.c
> @@ -33,6 +33,7 @@
>   #include<linux/delay.h>
>   #include<linux/io.h>
>   #include<linux/pinctrl/consumer.h>
> +#include<linux/of_device.h>
>
>   #include<asm/cacheflush.h>
>
> @@ -675,6 +676,30 @@ static struct uart_driver auart_driver = {
>   #endif
>   };
>
> +/*
> + * This function returns 1 if pdev isn't a device instatiated by dt, 0 if it
> + * could successfully get all information from dt or a negative errno.
> + */
> +static int serial_mxs_probe_dt(struct mxs_auart_port *s,
> +		struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	int ret;
> +
> +	if (!np)
> +		/* no device tree device */
> +		return 1;
> +
> +	ret = of_alias_get_id(np, "serial");
> +	if (ret<  0) {
> +		dev_err(&pdev->dev, "failed to get alias id: %d\n", ret);
> +		return ret;
> +	}
> +	s->port.line = ret;
> +
> +	return 0;
> +}
> +
>   static int __devinit mxs_auart_probe(struct platform_device *pdev)
>   {
>   	struct mxs_auart_port *s;
> @@ -689,6 +714,12 @@ static int __devinit mxs_auart_probe(struct platform_device *pdev)
>   		goto out;
>   	}
>
> +	ret = serial_mxs_probe_dt(s, pdev);
> +	if (ret>  0)
> +		s->port.line = pdev->id<  0 ? 0 : pdev->id;
> +	else if (ret<  0)
> +		goto out_free;
> +
>   	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
>   	if (IS_ERR(pinctrl)) {
>   		ret = PTR_ERR(pinctrl);
> @@ -711,7 +742,6 @@ static int __devinit mxs_auart_probe(struct platform_device *pdev)
>   	s->port.membase = ioremap(r->start, resource_size(r));
>   	s->port.ops =&mxs_auart_ops;
>   	s->port.iotype = UPIO_MEM;
> -	s->port.line = pdev->id<  0 ? 0 : pdev->id;
>   	s->port.fifosize = 16;
>   	s->port.uartclk = clk_get_rate(s->clk);
>   	s->port.type = PORT_IMX;
> @@ -769,12 +799,19 @@ static int __devexit mxs_auart_remove(struct platform_device *pdev)
>   	return 0;
>   }
>
> +static struct of_device_id mxs_auart_dt_ids[] = {
> +	{ .compatible = "fsl,imx23-auart", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids);
> +
>   static struct platform_driver mxs_auart_driver = {
>   	.probe = mxs_auart_probe,
>   	.remove = __devexit_p(mxs_auart_remove),
>   	.driver = {
>   		.name = "mxs-auart",
>   		.owner = THIS_MODULE,
> +		.of_match_table = mxs_auart_dt_ids,
>   	},
>   };
>
> @@ -807,3 +844,4 @@ module_init(mxs_auart_init);
>   module_exit(mxs_auart_exit);
>   MODULE_LICENSE("GPL");
>   MODULE_DESCRIPTION("Freescale MXS application uart driver");
> +MODULE_ALIAS("platform:mxs-auart");