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

From: Roger Quadros
Date: Wed Jul 09 2014 - 08:50:21 EST


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@xxxxxxxxx>
> ---
>
> 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
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