[PATCH 3/3] riscv: qemu: Implement is_flash_available() for MTD NOR

[Bin Meng]

On Sat, Jan 15, 2022 at 12:20 AM Anup Patel <apatel at ventanamicro.com> wrote:
>
> Currently, if MTD NOR is enabled then U-Boot tries to issue flash
> commands even when CFI flash DT node is not present. This causes
> access fault on RISC-V emulators or ISS which do not emulate CFI
> flash. To handle this issue, we implement is_flash_available() for
> qemu-riscv board which will return 1 only if CFI flash DT node is
> present.
>
> Fixes: d248627f9d42 ("riscv: qemu: Enable MTD NOR flash support")
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
>  board/emulation/qemu-riscv/qemu-riscv.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c
> index b0d9dd59b1..cd02dae1ab 100644
> --- a/board/emulation/qemu-riscv/qemu-riscv.c
> +++ b/board/emulation/qemu-riscv/qemu-riscv.c
> @@ -8,6 +8,7 @@
>  #include <env.h>
>  #include <fdtdec.h>
>  #include <image.h>
> +#include <linux/libfdt.h>
>  #include <log.h>
>  #include <spl.h>
>  #include <init.h>
> @@ -16,6 +17,22 @@
>
>  DECLARE_GLOBAL_DATA_PTR;
>
> +#if IS_ENABLED(CONFIG_MTD_NOR_FLASH)
> +int is_flash_available(void)
> +{
> +       if (IS_ENABLED(CONFIG_OF_SEPARATE) || IS_ENABLED(CONFIG_OF_BOARD)) {

Why is this if statement needed?

All QEMU riscv* defconfigs are using CONFIG_OF_BOARD, and there is no
OF_SEPARATE use case since QEMU DTBs are always consumed by U-Boot.

> +               const void *fdt =
> +                       (const void *)(uintptr_t)gd->arch.firmware_fdt_addr;
> +               int rc = fdt_node_offset_by_compatible(fdt, -1, "cfi-flash");
> +
> +               if (rc >= 0)
> +                       return 1;
> +       }
> +
> +       return 0;
> +}
> +#endif
> +
>  int board_init(void)
>  {
>         /*

Regards,
Bin