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

[Bin Meng]

On Tue, Jan 25, 2022 at 2:02 PM Anup Patel <apatel at ventanamicro.com> wrote:
>
> On Tue, Jan 25, 2022 at 10:33 AM Bin Meng <bmeng.cn at gmail.com> wrote:
> >
> > 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.
>
> I added the if statement for the case if someone disables CONFIG_OF_BOARD
> but I can remove it if you insist.
>

I see. But I if we give a dtb to QEMU without using CONFIG_OF_BOARD,
the dtb may still contain a node for flash so the logic you added is
still needed.

So I think you can just remove the if statement.

Also instead of using fdt_node_offset_by_compatible API please use
ofnode_device_is_compatible.

Regards,
Bin