[PATCH v3 1/5] lib: utils/fdt: Add fdt_parse_timebase_frequency() function

[Xiang W]

在 2021-09-25星期六的 10:07 +0530，Anup Patel写道：
> We add fdt_parse_timebase_frequency() function which can be used
> by ACLINT mtimer driver and platform code to get timebase frequency.
> 
> Signed-off-by: Anup Patel <anup.patel at wdc.com>
> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
Reviewed-by: Xiang W <wxjstz at 126.com>
> ---
>  include/sbi_utils/fdt/fdt_helper.h |  2 ++
>  lib/utils/fdt/fdt_helper.c         | 21 +++++++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/include/sbi_utils/fdt/fdt_helper.h
> b/include/sbi_utils/fdt/fdt_helper.h
> index 2246254..5cb7340 100644
> --- a/include/sbi_utils/fdt/fdt_helper.h
> +++ b/include/sbi_utils/fdt/fdt_helper.h
> @@ -50,6 +50,8 @@ int fdt_parse_hart_id(void *fdt, int cpu_offset,
> u32 *hartid);
>  
>  int fdt_parse_max_hart_id(void *fdt, u32 *max_hartid);
>  
> +int fdt_parse_timebase_frequency(void *fdt, unsigned long *freq);
> +
>  int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
>                                 struct platform_uart_data *uart);
>  
> diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
> index 5628337..5bf4021 100644
> --- a/lib/utils/fdt/fdt_helper.c
> +++ b/lib/utils/fdt/fdt_helper.c
> @@ -269,6 +269,27 @@ int fdt_parse_max_hart_id(void *fdt, u32
> *max_hartid)
>         return 0;
>  }
>  
> +int fdt_parse_timebase_frequency(void *fdt, unsigned long *freq)
> +{
> +       const fdt32_t *val;
> +       int len, cpus_offset;
> +
> +       if (!fdt || !freq)
> +               return SBI_EINVAL;
> +
> +       cpus_offset = fdt_path_offset(fdt, "/cpus");
> +       if (cpus_offset < 0)
> +               return cpus_offset;
> +
> +       val = fdt_getprop(fdt, cpus_offset, "timebase-frequency",
> &len);
> +       if (len > 0 && val)
> +               *freq = fdt32_to_cpu(*val);
> +       else
> +               return SBI_ENOENT;
> +
> +       return 0;
> +}
> +
>  int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
>                                 struct platform_uart_data *uart)
>  {
> -- 
> 2.25.1
> 
>