[PATCH RFC 1/2] gpio: Add a block GPIO API to gpiolib

Jean-Christophe PLAGNIOL-VILLARD plagnioj at jcrosoft.com
Fri Sep 28 05:08:48 EDT 2012


On 10:51 Fri 28 Sep     , Roland Stigge wrote:
> Hi!
> 
> On 09/28/2012 09:51 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> >> Right - will add checking for the request state of the respective GPIOs.
> >>
> >> The list of GPIOs to handle is defined by the offset (specified GPIO)
> >> and bitmapped list.
> >>
> >> If it looks more natural, I can change this to a list of ints specifying
> >> GPIOs directly.
> > you pass the correctly information to the gpiolib
> > 
> > as if you do not request the gpio the gpiolib will auto request the gpios
> > so you api will be 
> > int gpio_get_block(unsigned int *gpios, u8* values, size_t size);
> > 
> > return an error
> > 
> > int gpio_set_block(unsigned int *gpios, u8* set, size_t size);
> > 
> > so you do not care about the banks you work on the gpiolib framework will call
> > each gpio_chip seperatly. If the set_block get_block is not availlable the
> > gpiolib could fallback to get/set
> > 
> > inside of the gpiolib that you call each bank with a bitmapped list is correct
> > but not in the public gpiolib API
> 
> Good idea! Talking about the public API (your above gpio_set_block()):
> *gpios is a list of GPIOs, but set is still bitmapped (mapped onto the
> list specified in *gpios)? To prevent confusion about what the size
> argument means (number of gpios in *gpios _or_ number of bytes in the
> bitmap *set) - wouldn't it be clearer to have a "bool *set" and "bool
> *values" list?
public API list of gpio as example

gpios = {1, 33, 34, 55};
set = {1, 0, 0 ,1};

gpio_set_blocks(gpios, set, 4);

private you do just provide the array related to the gpio_chip
lets assume 4 bank with 32 gpio each

gpio0 = {1};
set0 = {1};

gpio1 = {33, 34};
set1 = {0, 0};

gpio2 = {55};
set2 = {1};

set_blocks(gpio_chip0, gpio0, set0, 1);
set_blocks(gpio_chip1, gpio1, set1, 2);
set_blocks(gpio_chip2, gpio2, set2, 1);

Best Regards,
J.



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