On Thu, Jun 1, 2017 at 10:28 PM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > On Thu, Jun 01, 2017 at 01:33:55PM -0700, Andrey Smirnov wrote: >> On Thu, Jun 1, 2017 at 12:19 AM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: >> > On Tue, May 30, 2017 at 07:52:26AM -0700, Andrey Smirnov wrote: >> >> So far this particular aspect of various DT-bindings has been handled >> >> on a per-driver basis. With this change, hopefully, we'll have a >> >> single place to handle necessary logic inversions and eventually >> >> would be able to migrate existing users as well as avoiding adding >> >> redundant code to new drivers. >> >> >> >> Cc: cphealy@xxxxxxxxx >> >> Cc: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx> >> >> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx> >> >> --- >> >> drivers/gpio/gpiolib.c | 42 ++++++++++++++++++++++++++++++++++++++++-- >> >> include/gpio.h | 20 ++++++++++++++++++++ >> >> 2 files changed, 60 insertions(+), 2 deletions(-) >> >> >> >> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c >> >> index 1f57c76..36d8874 100644 >> >> --- a/drivers/gpio/gpiolib.c >> >> +++ b/drivers/gpio/gpiolib.c >> >> @@ -13,6 +13,7 @@ static LIST_HEAD(chip_list); >> >> struct gpio_info { >> >> struct gpio_chip *chip; >> >> bool requested; >> >> + bool active_low; >> >> char *label; >> >> }; >> >> >> >> @@ -45,6 +46,15 @@ static struct gpio_info *gpio_to_desc(unsigned gpio) >> >> return NULL; >> >> } >> >> >> >> +static int gpio_adjust_value(struct gpio_info *gi, >> >> + int value) >> >> +{ >> >> + if (value < 0) >> >> + return value; >> >> + >> >> + return !!value ^ gi->active_low; >> >> +} >> >> + >> >> int gpio_request(unsigned gpio, const char *label) >> >> { >> >> struct gpio_info *gi = gpio_to_desc(gpio); >> >> @@ -69,6 +79,7 @@ int gpio_request(unsigned gpio, const char *label) >> >> } >> >> >> >> gi->requested = true; >> >> + gi->active_low = false; >> >> gi->label = xstrdup(label); >> >> >> >> done: >> >> @@ -93,6 +104,7 @@ void gpio_free(unsigned gpio) >> >> gi->chip->ops->free(gi->chip, gpio - gi->chip->base); >> >> >> >> gi->requested = false; >> >> + gi->active_low = false; >> >> free(gi->label); >> >> gi->label = NULL; >> >> } >> >> @@ -111,10 +123,15 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) >> >> if (err) >> >> return err; >> >> >> >> + if (flags & GPIOF_ACTIVE_LOW) { >> >> + struct gpio_info *gi = gpio_to_desc(gpio); >> >> + gi->active_low = true; >> >> + } >> >> + >> >> if (flags & GPIOF_DIR_IN) >> >> err = gpio_direction_input(gpio); >> >> else >> >> - err = gpio_direction_output(gpio, >> >> + err = gpio_direction_active(gpio, >> >> (flags & GPIOF_INIT_HIGH) ? 1 : 0); >> > >> > And here things get messy. >> > >> > For me 'high' and 'low' represent the physical values of a GPIO whereas >> > "active" and "inactive" represent the logical values of a GPIO. The flag >> > is named GPIOF_INIT_*HIGH*, not GPIOF_INIT_*ACTIVE*, which means a GPIO >> > with this flag should get the physical 'high' value, not the logical >> > 'active' value. >> > >> > They goofed the binding in the kernel, so I'm afraid there's nothing we >> > can do about this :( >> >> So do we want to: >> >> a) Keep things as is in v2(I am assuming that is not really an option) >> b) Improve the optics by introducing GPIOF_INIT_ACTIVE, but keeping >> the behavior of hog nodes consistent with Linux kernel > > We must keep the behaviour consistent with the Kernel, everything else > is not an option. A GPIOF_INIT_ACTIVE flag sounds like a good idea. The > place where "output-[high|low]" is translated into this flag seems a > good place to put a big comment what is going on. > Sounds good. I'll update the patchset accordingly. Thanks, Andrey Smirnov _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox