czw., 19 gru 2019 o 18:24 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> napisał(a): > > On Thu, Dec 19, 2019 at 06:15:27PM +0100, Bartosz Golaszewski wrote: > > From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx> > > > > Currently there is no way for user-space to be informed about changes > > in status of GPIO lines e.g. when someone else requests the line or its > > config changes. We can only periodically re-read the line-info. This > > is fine for simple one-off user-space tools, but any daemon that provides > > a centralized access to GPIO chips would benefit hugely from an event > > driven line info synchronization. > > > > This patch adds a new ioctl() that allows user-space processes to reuse > > the file descriptor associated with the character device for watching > > any changes in line properties. Every such event contains the updated > > line information. > > > > Currently the events are generated on three types of status changes: when > > a line is requested, when it's released and when its config is changed. > > The first two are self-explanatory. For the third one: this will only > > happen when another user-space process calls the new SET_CONFIG ioctl() > > as any changes that can happen from within the kernel (i.e. > > set_transitory() or set_debounce()) are of no interest to user-space. > > > > Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx> > > --- > > drivers/gpio/gpiolib.c | 191 ++++++++++++++++++++++++++++++++++++-- > > drivers/gpio/gpiolib.h | 1 + > > include/uapi/linux/gpio.h | 24 +++++ > > tools/gpio/gpio-watch | Bin 0 -> 26528 bytes > > Did you mean for this binary file to be checked in? > No, of course not, it's a mistake. I'll remove it in v4. Bart