Re: [PATCH] debugfs: allow to use regmap for print regs

[Greg Kroah-Hartman]

On Wed, Jan 11, 2023 at 02:15:41PM +0800, Li Chen wrote:
> Currently, debugfs_regset32 only contains void __iomem *base,
> and it is not friendly to regmap user.
> 
> Let's add regmap to debugfs_regset32, and add regmap
> support to debugfs_print_reg32.
> 
> Signed-off-by: Li Chen <me@linux.beauty>
> ---
>  fs/debugfs/file.c       | 23 +++++++++++++++++++----
>  include/linux/debugfs.h | 10 +++++++---
>  2 files changed, 26 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> index b54f470e0d03..c4663cfc20b6 100644
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -1112,8 +1112,10 @@ EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
>   * @regs: an array if struct debugfs_reg32 structures
>   * @nregs: the length of the above array
>   * @base: the base address to be used in reading the registers
> + * @regmap: regmap to be used in reading the registers
>   * @prefix: a string to be prefixed to every output line
>   *
> + * user should pick one of two from base and regmap
>   * This function outputs a text block describing the current values of
>   * some 32-bit hardware registers. It is meant to be used within debugfs
>   * files based on seq_file that need to show registers, intermixed with other
> @@ -1122,15 +1124,27 @@ EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
>   * for example configuration of dma channels
>   */
>  void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
> -			  int nregs, void __iomem *base, char *prefix)
> +			  int nregs, void __iomem *base, struct regmap *regmap,
> +			  char *prefix)

This is confusing, please just provide a new function for regmap instead
of trying to overload this function.  You can use the same function
inside the debugfs core like this, but never export such a complex set
of parameters to actual users, that's just painful.

thanks,

greg k-h