[u-boot][PATCH 10/14] mtd: rawnand: omap_gpmc: support u-boot driver model

[Adam Ford]

On Tue, Oct 11, 2022 at 6:52 AM Roger Quadros <rogerq at kernel.org> wrote:
>
> Adds driver model support.
>
> We need to be able to self initialize the NAND controller/chip
> at probe and so enable CONFIG_SYS_NAND_SELF_INIT.
>
> Doing so requires nand_register() API which is provided by nand.c
> and needs to be enabled during SPL build via CONFIG_SPL_NAND_INIT.
> But nand.c also provides nand_init() so we need to get rid of nand_init()
> in omap_gpmc driver if CONFIG_SPL_NAND_INIT is set.
>
> Signed-off-by: Roger Quadros <rogerq at kernel.org>
> ---
>  drivers/mtd/nand/raw/Kconfig     |  1 +
>  drivers/mtd/nand/raw/omap_gpmc.c | 55 +++++++++++++++++++++++++++++++-
>  2 files changed, 55 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> index bc5cabdfc2..1d23144ce4 100644
> --- a/drivers/mtd/nand/raw/Kconfig
> +++ b/drivers/mtd/nand/raw/Kconfig
> @@ -190,6 +190,7 @@ config NAND_LPC32XX_SLC
>  config NAND_OMAP_GPMC
>         bool "Support OMAP GPMC NAND controller"
>         depends on ARCH_OMAP2PLUS || ARCH_KEYSTONE || ARCH_K3
> +       select SYS_NAND_SELF_INIT if ARCH_K3

I have a question about this down below.

>         help
>           Enables omap_gpmc.c driver for OMAPx and AMxxxx platforms.
>           GPMC controller is used for parallel NAND flash devices, and can
> diff --git a/drivers/mtd/nand/raw/omap_gpmc.c b/drivers/mtd/nand/raw/omap_gpmc.c
> index e772a914c8..7192ca9e5a 100644
> --- a/drivers/mtd/nand/raw/omap_gpmc.c
> +++ b/drivers/mtd/nand/raw/omap_gpmc.c
> @@ -7,6 +7,7 @@
>  #include <common.h>
>  #include <log.h>
>  #include <asm/io.h>
> +#include <dm/uclass.h>
>  #include <linux/errno.h>
>
>  #ifdef CONFIG_ARCH_OMAP2PLUS
> @@ -1121,7 +1122,7 @@ int __maybe_unused omap_nand_switch_ecc(uint32_t hardware, uint32_t eccstrength)
>   *   nand_scan about special functionality. See the defines for further
>   *   explanation
>   */
> -int board_nand_init(struct nand_chip *nand)
> +int gpmc_nand_init(struct nand_chip *nand)
>  {
>         int32_t gpmc_config = 0;
>         int cs = cs_next++;
> @@ -1201,3 +1202,55 @@ int board_nand_init(struct nand_chip *nand)
>
>         return 0;
>  }
> +
> +static struct nand_chip *nand_chip;    /* First NAND chip for SPL use only */
> +
> +#if CONFIG_IS_ENABLED(SYS_NAND_SELF_INIT)
> +
> +static int gpmc_nand_probe(struct udevice *dev)
> +{
> +       struct nand_chip *nand = dev_get_priv(dev);
> +       struct mtd_info *mtd = nand_to_mtd(nand);
> +       int ret;
> +
> +       gpmc_nand_init(nand);
> +
> +       ret = nand_scan(mtd, CONFIG_SYS_NAND_MAX_CHIPS);
> +       if (ret)
> +               return ret;
> +
> +       ret = nand_register(0, mtd);
> +       if (ret)
> +               return ret;
> +
> +       if (!nand_chip)
> +               nand_chip = nand;
> +
> +       return 0;
> +}
> +
> +static const struct udevice_id gpmc_nand_ids[] = {
> +       { .compatible = "ti,am64-nand" },
> +       { .compatible = "ti,omap2-nand" },

The gpmc_nand_ids reference to omap2, but it's encapsulated inside the
SYS_NAND_SELF_INIT ifdef which appears to only be set if K3.  Should
this code be expected to work on OMAP2?  I don't think K3 is set for
OMAP2+.  If so, should the SYS_NAND_SELF_INIT be selected if OMAP2 is
selected?

I have a DM3730 that I can test with this.  Do you have a repo I can
point to to test?  If not, I'll pull the series from patchwork, but I
need to know what branch to use as a starting point.

thanks,

adam

> +       { }
> +};
> +
> +U_BOOT_DRIVER(gpmc_nand) = {
> +       .name           = "gpmc-nand",
> +       .id             = UCLASS_MTD,
> +       .of_match       = gpmc_nand_ids,
> +       .probe          = gpmc_nand_probe,
> +       .priv_auto      = sizeof(struct nand_chip),
> +};
> +
> +void board_nand_init(void)
> +{
> +       struct udevice *dev;
> +       int ret;
> +
> +       ret = uclass_get_device_by_driver(UCLASS_MTD,
> +                                         DM_DRIVER_GET(gpmc_nand), &dev);
> +       if (ret && ret != -ENODEV)
> +               pr_err("%s: Failed to get GPMC device: %d\n", __func__, ret);
> +}
> +#endif /* CONFIG_SYS_NAND_SELF_INIT */
> --
> 2.17.1
>