Re: [PATCH] ARM: omap2+: gpmc-nand: Use dynamic platform_device_alloc()

[Roger Quadros <rogerq@ti.com>]

Hi Rostislav,

On 06/04/2014 05:24 PM, Rostislav Lisovy wrote:
> GPMC controller supports up to 8 memory devices connected to it.
> Since there is one statically allocated "struct platform_device
> gpmc_nand_device" it is not possible to configure the system to
> use more than one NAND device connected to the GPMC. This
> modification makes it possible to use up to 8 NAND devices
> connected to the GPMC controller.
> 
> Signed-off-by: Rostislav Lisovy <lisovy@merica.cz>
> ---
> 
> Tested on custom AM335x board with two different NAND chips
> (128 + 256 MiB) using GPMC configuration in FDT -- behaves
> correctly.
> 
> 
>  arch/arm/mach-omap2/gpmc-nand.c | 79 +++++++++++++++++++----------------------
>  1 file changed, 37 insertions(+), 42 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/gpmc-nand.c b/arch/arm/mach-omap2/gpmc-nand.c
> index 4349e82..c5481a8 100644
> --- a/arch/arm/mach-omap2/gpmc-nand.c
> +++ b/arch/arm/mach-omap2/gpmc-nand.c
> @@ -24,25 +24,6 @@
>  /* minimum size for IO mapping */
>  #define	NAND_IO_SIZE	4
>  
> -static struct resource gpmc_nand_resource[] = {
> -	{
> -		.flags		= IORESOURCE_MEM,
> -	},
> -	{
> -		.flags		= IORESOURCE_IRQ,
> -	},
> -	{
> -		.flags		= IORESOURCE_IRQ,
> -	},
> -};
> -
> -static struct platform_device gpmc_nand_device = {
> -	.name		= "omap2-nand",
> -	.id		= 0,
> -	.num_resources	= ARRAY_SIZE(gpmc_nand_resource),
> -	.resource	= gpmc_nand_resource,
> -};
> -
>  static bool gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)
>  {
>  	/* platforms which support all ECC schemes */
> @@ -93,43 +74,41 @@ int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
>  {
>  	int err	= 0;
>  	struct gpmc_settings s;
> -	struct device *dev = &gpmc_nand_device.dev;
> -
> -	memset(&s, 0, sizeof(struct gpmc_settings));
> +	struct platform_device *pdev;
> +	struct resource gpmc_nand_res[] = {
> +		{ .flags = IORESOURCE_MEM, },
> +		{ .flags = IORESOURCE_IRQ, },
> +		{ .flags = IORESOURCE_IRQ, },
> +	};
>  
> -	gpmc_nand_device.dev.platform_data = gpmc_nand_data;
> +	BUG_ON(gpmc_nand_data->cs >= GPMC_CS_NUM);
>  
>  	err = gpmc_cs_request(gpmc_nand_data->cs, NAND_IO_SIZE,
> -				(unsigned long *)&gpmc_nand_resource[0].start);
> +			      (unsigned long *)&gpmc_nand_res[0].start);
>  	if (err < 0) {
> -		dev_err(dev, "Cannot request GPMC CS %d, error %d\n",
> -			gpmc_nand_data->cs, err);
> +		pr_err("omap2-gpmc: Cannot request GPMC CS %d, error %d\n",
> +		       gpmc_nand_data->cs, err);
>  		return err;
>  	}
> -
> -	gpmc_nand_resource[0].end = gpmc_nand_resource[0].start +
> -							NAND_IO_SIZE - 1;
> -
> -	gpmc_nand_resource[1].start =
> -				gpmc_get_client_irq(GPMC_IRQ_FIFOEVENTENABLE);
> -	gpmc_nand_resource[2].start =
> -				gpmc_get_client_irq(GPMC_IRQ_COUNT_EVENT);
> +	gpmc_nand_res[0].end = gpmc_nand_res[0].start + NAND_IO_SIZE - 1;
> +	gpmc_nand_res[1].start = gpmc_get_client_irq(GPMC_IRQ_FIFOEVENTENABLE);
> +	gpmc_nand_res[2].start = gpmc_get_client_irq(GPMC_IRQ_COUNT_EVENT);
>  
>  	if (gpmc_t) {
>  		err = gpmc_cs_set_timings(gpmc_nand_data->cs, gpmc_t);
>  		if (err < 0) {
> -			dev_err(dev, "Unable to set gpmc timings: %d\n", err);
> +			pr_err("omap2-gpmc: Unable to set gpmc timings: %d\n", err);
>  			return err;
>  		}
>  	}
>  
> +	memset(&s, 0, sizeof(struct gpmc_settings));
>  	if (gpmc_nand_data->of_node)
>  		gpmc_read_settings_dt(gpmc_nand_data->of_node, &s);
>  	else
>  		gpmc_set_legacy(gpmc_nand_data, &s);
>  
>  	s.device_nand = true;
> -
>  	err = gpmc_cs_program_settings(gpmc_nand_data->cs, &s);
>  	if (err < 0)
>  		goto out_free_cs;
> @@ -141,18 +120,34 @@ int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
>  	gpmc_update_nand_reg(&gpmc_nand_data->reg, gpmc_nand_data->cs);
>  
>  	if (!gpmc_hwecc_bch_capable(gpmc_nand_data->ecc_opt)) {
> -		dev_err(dev, "Unsupported NAND ECC scheme selected\n");
> -		return -EINVAL;
> +		pr_err("omap2-nand: Unsupported NAND ECC scheme selected\n");
> +		err = -EINVAL;
> +		goto out_free_cs;
>  	}
>  
> -	err = platform_device_register(&gpmc_nand_device);
> -	if (err < 0) {
> -		dev_err(dev, "Unable to register NAND device\n");
> -		goto out_free_cs;
> +
> +	pdev = platform_device_alloc("omap2-nand", gpmc_nand_data->cs);
> +	if (pdev) {
> +		err = platform_device_add_resources(pdev, gpmc_nand_res,
> +						    ARRAY_SIZE(gpmc_nand_res));
> +		if (!err)
> +			pdev->dev.platform_data = gpmc_nand_data;
> +	} else {
> +		err = -ENOMEM;
> +	}
> +	if (err)
> +		goto out_free_pdev;

There is a slight problem here. If platform_device_alloc() fails,
we must jump to 'out_free_cs' and not 'out_free_pdev'.

> +
> +	err = platform_device_add(pdev);
> +	if (err) {
> +		dev_err(&pdev->dev, "Unable to register NAND device\n");
> +		goto out_free_pdev;
>  	}
>  
>  	return 0;
>  
> +out_free_pdev:
> +	platform_device_put(pdev);
>  out_free_cs:
>  	gpmc_cs_free(gpmc_nand_data->cs);
>  
> 

cheers,
-roger