Re: [PATCH v13 1/4] drivers pps/generators: replace copy of pps-gen info struct with const pointer
From: Andy Shevchenko
Date: Mon Feb 10 2025 - 01:05:13 EST
On Mon, Feb 10, 2025 at 10:34:18AM +0530, subramanian.mohan@xxxxxxxxx wrote:
> From: Subramanian Mohan <subramanian.mohan@xxxxxxxxx>
>
> Some PPS generator drivers may need to retrieve a pointer to their
> internal data while executing the PPS generator enable() method.
>
> During the driver registration the pps_gen_device pointer is returned
> from the framework, and for that reason, there is difficulty in
> getting generator driver data back in the enable function. We won't be
> able to use container_of macro as it results in static assert, and we
> might end up in using static pointer.
>
> To solve the issue and to get back the generator driver data back, we
> should not copy the struct pps_gen_source_info within the struct
> pps_gen_device during the registration stage, but simply save the
> pointer of the driver one. In this manner, driver may get a pointer
> to their internal data as shown below:
>
> struct pps_gen_foo_data_s {
> ...
> struct pps_gen_source_info gen_info;
> struct pps_gen_device *pps_gen;
> ...
> };
>
> static int __init pps_gen_foo_init(void)
> {
> struct pps_gen_foo_data_s *foo;
> ...
>
> foo->pps_gen = pps_gen_register_source(&foo->gen_info);
> ...
> }
>
> Then, in the enable() method, we can retrieve the pointer to the main
> struct by using the code below:
>
> static int pps_gen_foo_enable(struct pps_gen_device *pps_gen, bool enable)
> {
> struct pps_gen_foo_data_s *foo = container_of(pps_gen->info,
> struct pps_gen_foo_data_s, gen_info);
TABs/spaces mix.
> ...
> }
> Signed-off-by: Rodolfo Giometti <giometti@xxxxxxxxxxxx>
Hmm... Is Rodolfo indeed a correct to be mentioned here?
I think you wanted Suggested-by with somebody else.
...
> -struct pps_gen_device *pps_gen_register_source(struct pps_gen_source_info *info)
> +struct pps_gen_device *pps_gen_register_source(
> + const struct pps_gen_source_info *info)
Still leave it a single line.
...
Otherwise looks good to me, thanks for taking this approach!
--
With Best Regards,
Andy Shevchenko