[PATCH 1/1] lib: utils: identify supported GPIO reset methods

[Heinrich Schuchardt <heinrich.schuchardt@canonical.com>]

On 9/29/21 6:16 AM, Anup Patel wrote:
> +Nikita
> 
> On Tue, Sep 28, 2021 at 5:13 PM Heinrich Schuchardt
> <heinrich.schuchardt@canonical.com> wrote:
>>
>> The GPIO reset driver supports reset and poweroff. But not all boards
>> support both. gpio_system_reset_check() must detect this situation.
>>
>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> 
> Looks good to me.
> 
> Reviewed-by: Anup Patel <anup.patel@wdc.com>
> 
> I had mentioned on the PMIC reset series that we need to improve
> the sbi_system.h device registration such that reset drivers can
> register a reset device for a range of reset types. This will allow
> separate reset drivers (e.g. PMIC+GPIO) for SiFive Unmatched.
> Also, reset_check() callback will not be required anymore.

Hello Anup,

thanks for reviewing.

Currently we keep a list of drivers in a static array. As we are 
acquiring more and drivers I would like to move to linker generated 
lists as Linux and U-Boot use the for enumerating drivers.

So a driver could look like:

int drv1_check(unsigned int type, unsigned int reason) {...}

void drv1_reset(unsigned int type, unsigned int reason) {...}

SRST_DRIVER(drv1) = {
         .name = "driver_1",
         .check = drv1_check,
         .reset = drv1_reset,
};

The linker will create a list of all SRST_DRIVER() instances over which 
we can iterate in our code.

Does this make sense to you?

Example code is available in
https://github.com/xypron/linker_generated_lists

Best regards

Heinrich