Re: [PATCH v3 2/2] serial: mxs-auart: Allow device tree probing

[Marek Vasut <marex@denx.de>]

Dear Fabio Estevam,

> Allow device tree probing.
> 
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Cc: Rob Herring <rob.herring@calxeda.com>
> Cc: Alan Cox <alan@linux.intel.com>
> Cc: <linux-serial@vger.kernel.org>
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

Acked-by: Marek Vasut <marex@denx.de>

> ---
> 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                     |   49
> +++++++++++++++++++- 2 files changed, 75 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@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..87bbe9c 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;
> @@ -769,13 +799,29 @@ static int __devexit mxs_auart_remove(struct
> platform_device *pdev) return 0;
>  }
> 
> +static struct platform_device_id mxs_auart_devtype[] = {
> +	{
> +		.name = "mxs-auart",
> +		/* sentinel */
> +	}
> +};
> +MODULE_DEVICE_TABLE(platform, mxs_auart_devtype);
> +
> +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,
>  	},
> +		.id_table = mxs_auart_devtype,
>  };
> 
>  static int __init mxs_auart_init(void)
> @@ -807,3 +853,4 @@ 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");

Best regards,
Marek Vasut