[PATCH 1/1] mtd: cfi_flash: read device tree correctly

[Rick Chen]

Hi Heinrich

> From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Heinrich Schuchardt
> Sent: Tuesday, July 21, 2020 10:51 AM
> To: Stefan Roese
> Cc: Simon Glass; u-boot at lists.denx.de; Heinrich Schuchardt
> Subject: [PATCH 1/1] mtd: cfi_flash: read device tree correctly
>
> dev_read_size_cells() and dev_read_addr_cells() do not walk up the device tree to find the number of cells. On error they return 1 and 2 respectively. On qemu_arm64_defconfig this leads to the incorrect detection of address of the second flash bank as 0x400000000000000 instead of 0x4000000.
>
> When running
>
>     qemu-system-aarch64 -machine virt -bios u-boot.bin \
>     -cpu cortex-a53 -nographic \
>     -drive if=pflash,format=raw,index=1,file=envstore.img
>
> the command 'saveenv' fails with
>
>     Saving Environment to Flash... Error: start and/or end address not on
>     sector boundary
>     Error: start and/or end address not on sector boundary
>     Failed (1)
>
> due to this incorrect address.
>
> Use function fdtdec_get_addr_size_auto_noparent() to read the array of flash banks from the device tree.
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  drivers/mtd/cfi_flash.c | 20 ++++++++------------
>  1 file changed, 8 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c index b7289ba539..dfa104bcf0 100644
> --- a/drivers/mtd/cfi_flash.c
> +++ b/drivers/mtd/cfi_flash.c
> @@ -2469,28 +2469,24 @@ unsigned long flash_init(void)  static int cfi_flash_probe(struct udevice *dev)  {
>         const fdt32_t *cell;
> -       int addrc, sizec;
> -       int len, idx;
> -
> -       addrc = dev_read_addr_cells(dev);
> -       sizec = dev_read_size_cells(dev);
> +       int len;
>
>         /* decode regs; there may be multiple reg tuples. */
>         cell = dev_read_prop(dev, "reg", &len);
>         if (!cell)
>                 return -ENOENT;
> -       idx = 0;
> -       len /= sizeof(fdt32_t);
> -       while (idx < len) {
> +
> +       for (cfi_flash_num_flash_banks = 0; ; ++cfi_flash_num_flash_banks) {
>                 phys_addr_t addr;
>
> -               addr = dev_translate_address(dev, cell + idx);
> +               addr = fdtdec_get_addr_size_auto_noparent(
> +                               gd->fdt_blob, dev_of_offset(dev), "reg",
> +                               cfi_flash_num_flash_banks, NULL, false);
> +               if (addr == FDT_ADDR_T_NONE)
> +                       break;
>
>                 flash_info[cfi_flash_num_flash_banks].dev = dev;
>                 flash_info[cfi_flash_num_flash_banks].base = addr;
> -               cfi_flash_num_flash_banks++;
> -
> -               idx += addrc + sizec;
>         }
>         gd->bd->bi_flashstart = flash_info[0].base;
>
> --
> 2.27.0
>

This patch remind me that I have encounter flash bank detection
problem on AE350 platform a period time ago.
And have commit a patch to work around this problem as below:

commit cca8b1e5b20cdab7299a5ee7139e70783f73ccdf

    riscv: dts: Add #address-cells and #size-cells in nor node

    Those are required for cfi-flash driver to get correct address information.
    Also modify size description correctly.

With this patch, there is unnecessary to re-declaration address-cells
and size-cells in nor node indeed.

Tested-by: Rick Chen <rick at andestech.com>

Thanks,
Rick