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

[Roger Quadros <rogerq@ti.com>]

On 07/09/2014 03:49 PM, Roger Quadros wrote:
> 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'.

Nevermind. It shouldn't be a problem as platform_device_put() checks for NULL pdev.

cheers,
-roger