hold the gpiobus lock between the gpio calls.
gpiobus_acquire_lock() now accepts a third parameter which tells gpiobus
what to do when the bus is already busy.
When GPIOBUS_WAIT wait is used, the calling thread will be put to sleep
until the bus became free.
With GPIOBUS_DONTWAIT the calling thread will receive EWOULDBLOCK right
away and then it can act upon.
This fixes the gpioiic(4) locking issues that arises when doing multiple
concurrent access on the bus.
gpioled(4).
Tested on RPi and BBB (using the hardware I2C controller and gpioiic(4) for
the I2C tests). It was also verified for regressions on RSPRO (MIPS/ar71xx)
used as reference for a non OFW-based system.
Update the gpioled(4) and gpioiic(4) man pages with some details and
examples about the FDT/OFW support.
Some compatibility details pointed out by imp@ will follow in subsequent
commits.
Approved by: adrian (mentor, implicit)
- license clause now contains "AUTHOR AND CONTRIBUTORS"
instead of just "AUTHOR"
- Add license/copyright to gpioc.c
Spotted by: Edward Tomasz Napierala, Andrew Turner
- GPIO bus controller interface
- GPIO bus interface
- Implementation of GPIO led(4) compatible device
- Implementation of iic(4) bus over GPIO (author: Luiz Otavio O Souza)
Tested by: Luiz Otavio O Souza, Alexandr Rybalko
