[PATCH 1/3] serial: mxs-auart: distinguish the different SOCs

[Shawn Guo]

On Tue, Oct 16, 2012 at 02:03:04PM +0800, Huang Shijie wrote:
> From: Huang Shijie <shijie8 at gmail.com>
> 
> The current mxs-auart driver is used for both mx23 and mx28.
> 
> But in mx23, the DMA has a bug(see errata:2836). We can not add the
> DMA support in mx23, but we can add DMA support to auart in mx28.
> 
> So in order to add the DMA support for the auart in mx28, we should add
> the platform_device_id to distinguish the distinguish SOCs.
> 
> Signed-off-by: Huang Shijie <b32955 at freescale.com>
> ---
>  .../bindings/tty/serial/fsl-mxs-auart.txt          |    2 +-
>  arch/arm/boot/dts/imx28.dtsi                       |   10 +++---
>  drivers/tty/serial/mxs-auart.c                     |   28 +++++++++++++++----
>  3 files changed, 28 insertions(+), 12 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
> index 2ee903f..a154bf1 100644
> --- a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
> +++ b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
> @@ -8,7 +8,7 @@ Required properties:
>  
>  Example:
>  auart0: serial at 8006a000 {
> -	compatible = "fsl,imx28-auart", "fsl,imx23-auart";
> +	compatible = "fsl,imx28-auart";
>  	reg = <0x8006a000 0x2000>;
>  	interrupts = <112 70 71>;
>  };
> diff --git a/arch/arm/boot/dts/imx28.dtsi b/arch/arm/boot/dts/imx28.dtsi
> index e16d631..6ed9215 100644
> --- a/arch/arm/boot/dts/imx28.dtsi
> +++ b/arch/arm/boot/dts/imx28.dtsi
> @@ -795,7 +795,7 @@
>  			};
>  
>  			auart0: serial at 8006a000 {
> -				compatible = "fsl,imx28-auart", "fsl,imx23-auart";
> +				compatible = "fsl,imx28-auart";
>  				reg = <0x8006a000 0x2000>;
>  				interrupts = <112 70 71>;
>  				clocks = <&clks 45>;
> @@ -803,7 +803,7 @@
>  			};
>  
>  			auart1: serial at 8006c000 {
> -				compatible = "fsl,imx28-auart", "fsl,imx23-auart";
> +				compatible = "fsl,imx28-auart";
>  				reg = <0x8006c000 0x2000>;
>  				interrupts = <113 72 73>;
>  				clocks = <&clks 45>;
> @@ -811,7 +811,7 @@
>  			};
>  
>  			auart2: serial at 8006e000 {
> -				compatible = "fsl,imx28-auart", "fsl,imx23-auart";
> +				compatible = "fsl,imx28-auart";
>  				reg = <0x8006e000 0x2000>;
>  				interrupts = <114 74 75>;
>  				clocks = <&clks 45>;
> @@ -819,7 +819,7 @@
>  			};
>  
>  			auart3: serial at 80070000 {
> -				compatible = "fsl,imx28-auart", "fsl,imx23-auart";
> +				compatible = "fsl,imx28-auart";
>  				reg = <0x80070000 0x2000>;
>  				interrupts = <115 76 77>;
>  				clocks = <&clks 45>;
> @@ -827,7 +827,7 @@
>  			};
>  
>  			auart4: serial at 80072000 {
> -				compatible = "fsl,imx28-auart", "fsl,imx23-auart";
> +				compatible = "fsl,imx28-auart";
>  				reg = <0x80072000 0x2000>;
>  				interrupts = <116 78 79>;
>  				clocks = <&clks 45>;

All changes above are unnecessary.  With "fsl,imx28-auart" added to
driver's compatible, driver will match it first.

> diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
> index 6db3baa..cd9ec1d 100644
> --- a/drivers/tty/serial/mxs-auart.c
> +++ b/drivers/tty/serial/mxs-auart.c
> @@ -37,6 +37,11 @@
>  
>  #include <asm/cacheflush.h>
>  
> +/* Use the platform_id to distinguish different Archs. */
> +#define IS_MX23			0x0
> +#define IS_MX28			0x1

I do not like the name.  We are distinguishing the IP not SoC, but just
happen to use SoC to identify the version.

You can look at drivers/mmc/host/sdhci-esdhc-imx.c for example.

> +#define AUART_IS_MX23(x)	((x)->pdev->id_entry->driver_data == IS_MX23)
> +

Use inline function.

>  #define MXS_AUART_PORTS 5
>  
>  #define AUART_CTRL0			0x00000000
> @@ -124,6 +129,7 @@ struct mxs_auart_port {
>  
>  	struct clk *clk;
>  	struct device *dev;
> +	struct platform_device *pdev;
>  };
>  
>  static void mxs_auart_stop_tx(struct uart_port *u);
> @@ -680,6 +686,19 @@ static struct uart_driver auart_driver = {
>  #endif
>  };
>  
> +static const struct platform_device_id auart_ids[] = {
> +	{ .name = "imx23-auart", .driver_data = IS_MX23, },
> +	{ .name = "imx28-auart", .driver_data = IS_MX28, },
> +	{},
> +};
> +

The driver is only used on mach-mxs.  Since mach-mxs becomes a DT only
platform, auart_ids is not really needed.  Look, you do not use it in
mxs_auart_driver for probing at all.

> +static struct of_device_id mxs_auart_dt_ids[] = {
> +	{ .compatible = "fsl,imx23-auart", .data = (void *)&auart_ids[0] },
> +	{ .compatible = "fsl,imx28-auart", .data = (void *)&auart_ids[1] },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids);
> +
>  /*
>   * 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.
> @@ -701,6 +720,8 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s,
>  	}
>  	s->port.line = ret;
>  
> +	pdev->id_entry = of_match_device(mxs_auart_dt_ids, &pdev->dev)->data;
> +
>  	return 0;
>  }
>  
> @@ -753,6 +774,7 @@ static int __devinit mxs_auart_probe(struct platform_device *pdev)
>  
>  	s->flags = 0;
>  	s->ctrl = 0;
> +	s->pdev = pdev;

What is this for?

Shawn

>  
>  	s->irq = platform_get_irq(pdev, 0);
>  	s->port.irq = s->irq;
> @@ -805,12 +827,6 @@ 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),
> -- 
> 1.7.0.4
> 
>