Re: [PATCH v2] gpiolib: Export gpiochip_request_own_desc and gpiochip_free_own_desc

Guenter Roeck
2014-07-22T06:53:30Z

On 07/21/2014 11:43 PM, Mika Westerberg wrote:
> On Mon, Jul 21, 2014 at 10:18:25PM -0700, Guenter Roeck wrote:
>> Both functions were introduced to let gpio drivers request their own
>> gpio pins. Without exporting the functions, this can however only be
>> used by gpio drivers built into the kernel.
>
> The reason why these are private to drivers is that those are dangerous
> if used blindly.
>
>> Secondary impact is that the functions can not currently be used by
>> platform initialization code associated with the gpio-pca953x driver.
>> This code permits auto-export of gpio pins through platform data, but
>> if this functionality is used, the module can no longer be unloaded due
>> to the problem solved with the introduction of gpiochip_request_own_desc
>> and gpiochip_free_own_desc.
>>
>> Export both function so they can be used from modules and from
>> platform initialization code.
>
> However, you have valid reason above. I wonder if this requires
> some documentation in Documentation/gpio/driver.txt?
>
Sure. Any idea what I should write, or do you want me to come up with something ?

>> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>> ---
>> v2: Move function declarations from consumer.h to driver.h.
>>
>> drivers/gpio/gpiolib.c | 2 ++
>> drivers/gpio/gpiolib.h | 3 ---
>> include/linux/gpio/driver.h | 3 +++
>> 3 files changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
>> index 43d9e34..04c647e 100644
>> --- a/drivers/gpio/gpiolib.c
>> +++ b/drivers/gpio/gpiolib.c
>> @@ -1953,6 +1953,7 @@ int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
>>
>> return __gpiod_request(desc, label);
>> }
>> +EXPORT_SYMBOL(gpiochip_request_own_desc);
>
> EXPORT_SYMBOL_GPL?
>
Ok.

Thanks,
Guenter