[PATCH 1/3] ARM: pxa: Add DT support to pxa2xx-uart

[Grant Likely]

On Tue, Nov 01, 2011 at 07:32:32PM +0100, Marek Vasut wrote:
> Add device tree binding for PXA2xx UARTs. Tested on Vpac270 board.
> 
> Signed-off-by: Marek Vasut <marek.vasut at gmail.com>
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Grant Likely <grant.likely at secretlab.ca>
> ---
>  drivers/tty/serial/pxa.c |   50 +++++++++++++++++++++++++++++++++++++++++++--
>  1 files changed, 47 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
> index 531931c..836cbb4 100644
> --- a/drivers/tty/serial/pxa.c
> +++ b/drivers/tty/serial/pxa.c
> @@ -43,6 +43,8 @@
>  #include <linux/clk.h>
>  #include <linux/io.h>
>  #include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>  
>  struct uart_pxa_port {
>  	struct uart_port        port;
> @@ -761,11 +763,50 @@ static const struct dev_pm_ops serial_pxa_pm_ops = {
>  };
>  #endif
>  
> +#ifdef CONFIG_OF
> +static struct of_device_id serial_pxa_dt_ids[] = {
> +	{ .compatible = "marvell,pxa2xx-uart" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
> +
> +static int serial_pxa_probe_dt(struct platform_device *pdev, int *portid)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	static int portnum;
> +
> +	if (!np)
> +		return -ENODEV;
> +
> +	/* PXA has up to four UART ports */
> +	*portid = portnum++;
> +	if (*portid >= 4)
> +		return -ENODEV;
> +
> +	/* Check if we're probing compatible ports only! */
> +	if (of_get_property(np, "marvell,pxa250", NULL))

This looks wrong.  Compatibility should be based solely on the
'compatible' property of the device node.  A separate
of_get_property() doesn't make much sense.  You can use
of_device_is_compatible(), or a better option would probably be to use
of_match_device() so that you can add additional setup data from the
.data field in the serial_pxa_dt_ids list.

> +		if (!cpu_is_pxa25x())
> +			return -EINVAL;

Do you really want to fail silently here?  If the cpu does not match
pxa25x, then there is something very wrong with the device tree data
for the machine.  I would fail loudly with WARN_ON() or dev_err().  :-)

> +
> +	return 0;
> +}
> +#else
> +static inline int serial_pxa_probe_dt(struct platform_device *pdev, int *portid)
> +{
> +	return 0;
> +}
> +#endif
> +
>  static int serial_pxa_probe(struct platform_device *dev)
>  {
>  	struct uart_pxa_port *sport;
>  	struct resource *mmres, *irqres;
>  	int ret;
> +	int portid = dev->id;
> +
> +	ret = serial_pxa_probe_dt(dev, &portid);
> +	if (ret == -EINVAL)
> +		return 0;
>  
>  	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
>  	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
> @@ -788,12 +829,12 @@ static int serial_pxa_probe(struct platform_device *dev)
>  	sport->port.irq = irqres->start;
>  	sport->port.fifosize = 64;
>  	sport->port.ops = &serial_pxa_pops;
> -	sport->port.line = dev->id;
> +	sport->port.line = portid;
>  	sport->port.dev = &dev->dev;
>  	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
>  	sport->port.uartclk = clk_get_rate(sport->clk);
>  
> -	switch (dev->id) {
> +	switch (portid) {
>  	case 0: sport->name = "FFUART"; break;
>  	case 1: sport->name = "BTUART"; break;
>  	case 2: sport->name = "STUART"; break;
> @@ -809,7 +850,7 @@ static int serial_pxa_probe(struct platform_device *dev)
>  		goto err_clk;
>  	}
>  
> -	serial_pxa_ports[dev->id] = sport;
> +	serial_pxa_ports[portid] = sport;
>  
>  	uart_add_one_port(&serial_pxa_reg, &sport->port);
>  	platform_set_drvdata(dev, sport);
> @@ -846,6 +887,9 @@ static struct platform_driver serial_pxa_driver = {
>  #ifdef CONFIG_PM
>  		.pm	= &serial_pxa_pm_ops,
>  #endif
> +#ifdef CONFIG_OF
> +		.of_match_table = serial_pxa_dt_ids,
> +#endif

Doing it this way eliminates the #ifdef:

	.of_match_table = of_match_ptr(serial_pxa_dt_ids),

Otherwise looks good.

g.