[U-Boot] [PATCH v2] fdt: Pass the device serial number through devicetree

[Simon Glass]

Hi Paul,

On 21 May 2015 at 03:27, Paul Kocialkowski <contact at paulk.fr> wrote:
> Before device-tree, the device serial number used to be passed to the kernel
> using ATAGs (on ARM). This is now deprecated and all the handover to the kernel
> should now be done using device-tree. Thus, this passes the serial-number
> property to the kernel using the serial-number property of the root node, as
> expected by the kernel.
>
> The serial number is a string that somewhat represents the device's serial
> number. It might come from some form of storage (e.g. an eeprom) and be
> programmed at factory-time by the manufacturer or come from identification
> bits available in e.g. the SoC.
>
> Signed-off-by: Paul Kocialkowski <contact at paulk.fr>

Reviewed-by: Simon Glass <sgj at chromium.org>

But please see a nit below.

> ---
>  common/fdt_support.c              | 25 +++++++++++++++++++++++++
>  common/image-fdt.c                |  4 ++++
>  doc/device-tree-bindings/root.txt |  4 ++++
>  include/fdt_support.h             |  1 +
>  4 files changed, 34 insertions(+)
>  create mode 100644 doc/device-tree-bindings/root.txt
>
> diff --git a/common/fdt_support.c b/common/fdt_support.c
> index 9e50148..10648b5 100644
> --- a/common/fdt_support.c
> +++ b/common/fdt_support.c
> @@ -194,6 +194,31 @@ static inline int fdt_setprop_uxx(void *fdt, int nodeoffset, const char *name,
>                 return fdt_setprop_u32(fdt, nodeoffset, name, (uint32_t)val);
>  }
>
> +int fdt_root(void *fdt)
> +{
> +       char *serial;
> +       int err;
> +
> +       err = fdt_check_header(fdt);
> +       if (err < 0) {
> +               printf("fdt_root: %s\n", fdt_strerror(err));
> +               return err;
> +       }
> +
> +       serial = getenv("serial#");
> +       if (serial) {
> +               err = fdt_setprop(fdt, 0, "serial-number", serial,
> +                                 strlen(serial) + 1);
> +
> +               if (err < 0) {
> +                       printf("WARNING: could not set serial-number %s.\n",
> +                              fdt_strerror(err));
> +                       return err;
> +               }
> +       }
> +
> +       return 0;
> +}
>
>  int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end)
>  {
> diff --git a/common/image-fdt.c b/common/image-fdt.c
> index 7e2da7b..80e3e63 100644
> --- a/common/image-fdt.c
> +++ b/common/image-fdt.c
> @@ -471,6 +471,10 @@ int image_setup_libfdt(bootm_headers_t *images, void *blob,
>         int ret = -EPERM;
>         int fdt_ret;
>
> +       if (fdt_root(blob) < 0) {
> +               printf("ERROR: root node setup failed\n");
> +               goto err;
> +       }
>         if (fdt_chosen(blob) < 0) {
>                 printf("ERROR: /chosen node create failed\n");
>                 goto err;
> diff --git a/doc/device-tree-bindings/root.txt b/doc/device-tree-bindings/root.txt
> new file mode 100644
> index 0000000..001ccf3
> --- /dev/null
> +++ b/doc/device-tree-bindings/root.txt
> @@ -0,0 +1,4 @@
> +The root node
> +
> +Optional properties:
> +  - serial-number : a string representing the device's serial number
> diff --git a/include/fdt_support.h b/include/fdt_support.h
> index 5d4f28d..56185c9 100644
> --- a/include/fdt_support.h
> +++ b/include/fdt_support.h
> @@ -16,6 +16,7 @@ u32 fdt_getprop_u32_default_node(const void *fdt, int off, int cell,
>                                 const char *prop, const u32 dflt);
>  u32 fdt_getprop_u32_default(const void *fdt, const char *path,
>                                 const char *prop, const u32 dflt);
> +int fdt_root(void *fdt);

Please can you add a comment for this in the standard style?

>  int fdt_chosen(void *fdt);
>  int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end);
>  void do_fixup_by_path(void *fdt, const char *path, const char *prop,
> --
> 1.9.1
>

Regards,
Simon