[U-Boot] [PATCH 2/4] fdt: Introduce fdtdec_get_alias_highest_id()

[Simon Glass]

Hi Michal,

On Fri, 18 Jan 2019 at 08:13, Michal Simek <michal.simek at xilinx.com> wrote:
>
> Find out the highest alias ID used for certain subsystem.
> This call will be used for alocating IDs for i2c buses which are not
> described in DT.
>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
>
>  include/fdtdec.h | 13 +++++++++++++
>  lib/fdtdec.c     | 33 +++++++++++++++++++++++++++++++++
>  2 files changed, 46 insertions(+)
>
> diff --git a/include/fdtdec.h b/include/fdtdec.h
> index f1bcbf837ffb..c2dd87ede226 100644
> --- a/include/fdtdec.h
> +++ b/include/fdtdec.h
> @@ -626,6 +626,19 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
>                          int *seqp);
>
>  /**
> + * Get the highest alias number for susbystem.
> + *
> + * It parses all aliases and find out highest recorded alias for subsystem.
> + * Aliases are of the form <base><num> where <num> is the sequence number.
> + *
> + * @param blob         Device tree blob (if NULL, then error is returned)
> + * @param base         Base name for alias susbystem (before the number)
> + *
> + * @return 0 highest alias ID, -1 if not found
> + */
> +int fdtdec_get_alias_highest_id(const void *blob, const char *base);
> +
> +/**
>   * Get a property from the /chosen node
>   *
>   * @param blob         Device tree blob (if NULL, then NULL is returned)
> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
> index 18663ce6bdac..55811975ef54 100644
> --- a/lib/fdtdec.c
> +++ b/lib/fdtdec.c
> @@ -549,6 +549,39 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int offset,
>         return -ENOENT;
>  }
>
> +int fdtdec_get_alias_highest_id(const void *blob, const char *base)
> +{
> +       int base_len = strlen(base);
> +       int prop_offset;
> +       int aliases;
> +       int max = -1;
> +
> +       debug("Looking for highest alias id for '%s'\n", base);
> +
> +       aliases = fdt_path_offset(blob, "/aliases");
> +       for (prop_offset = fdt_first_property_offset(blob, aliases);
> +            prop_offset > 0;
> +            prop_offset = fdt_next_property_offset(blob, prop_offset)) {
> +               const char *prop;
> +               const char *name;
> +               int len, val;
> +
> +               prop = fdt_getprop_by_offset(blob, prop_offset, &name, &len);
> +               debug("   - %s, %s\n", name, prop);
> +               if (*prop != '/' || prop[len - 1] ||
> +                   strncmp(name, base, base_len))
> +                       continue;
> +
> +               val = trailing_strtol(name);
> +               if (val > max) {
> +                       debug("Found seq %d\n", val);
> +                       max = val;
> +               }
> +       }
> +
> +       return max;

This looks right to me. Can you please add a test that calls this for
a few sandbox aliases?

> +}
> +
>  const char *fdtdec_get_chosen_prop(const void *blob, const char *name)
>  {
>         int chosen_node;
> --
> 1.9.1
>

Regards,
Simon


On Fri, 18 Jan 2019 at 08:13, Michal Simek <michal.simek at xilinx.com> wrote:
>
> Find out the highest alias ID used for certain subsystem.
> This call will be used for alocating IDs for i2c buses which are not
> described in DT.
>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
>
>  include/fdtdec.h | 13 +++++++++++++
>  lib/fdtdec.c     | 33 +++++++++++++++++++++++++++++++++
>  2 files changed, 46 insertions(+)
>
> diff --git a/include/fdtdec.h b/include/fdtdec.h
> index f1bcbf837ffb..c2dd87ede226 100644
> --- a/include/fdtdec.h
> +++ b/include/fdtdec.h
> @@ -626,6 +626,19 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
>                          int *seqp);
>
>  /**
> + * Get the highest alias number for susbystem.
> + *
> + * It parses all aliases and find out highest recorded alias for subsystem.
> + * Aliases are of the form <base><num> where <num> is the sequence number.
> + *
> + * @param blob         Device tree blob (if NULL, then error is returned)
> + * @param base         Base name for alias susbystem (before the number)
> + *
> + * @return 0 highest alias ID, -1 if not found
> + */
> +int fdtdec_get_alias_highest_id(const void *blob, const char *base);
> +
> +/**
>   * Get a property from the /chosen node
>   *
>   * @param blob         Device tree blob (if NULL, then NULL is returned)
> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
> index 18663ce6bdac..55811975ef54 100644
> --- a/lib/fdtdec.c
> +++ b/lib/fdtdec.c
> @@ -549,6 +549,39 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int offset,
>         return -ENOENT;
>  }
>
> +int fdtdec_get_alias_highest_id(const void *blob, const char *base)
> +{
> +       int base_len = strlen(base);
> +       int prop_offset;
> +       int aliases;
> +       int max = -1;
> +
> +       debug("Looking for highest alias id for '%s'\n", base);
> +
> +       aliases = fdt_path_offset(blob, "/aliases");
> +       for (prop_offset = fdt_first_property_offset(blob, aliases);
> +            prop_offset > 0;
> +            prop_offset = fdt_next_property_offset(blob, prop_offset)) {
> +               const char *prop;
> +               const char *name;
> +               int len, val;
> +
> +               prop = fdt_getprop_by_offset(blob, prop_offset, &name, &len);
> +               debug("   - %s, %s\n", name, prop);
> +               if (*prop != '/' || prop[len - 1] ||
> +                   strncmp(name, base, base_len))
> +                       continue;
> +
> +               val = trailing_strtol(name);
> +               if (val > max) {
> +                       debug("Found seq %d\n", val);
> +                       max = val;
> +               }
> +       }
> +
> +       return max;
> +}
> +
>  const char *fdtdec_get_chosen_prop(const void *blob, const char *name)
>  {
>         int chosen_node;
> --
> 1.9.1
>