I'm working with a TunnelCreek + EG20T platform which has two GPIO drivers:
gpio-sch - for the CPU GPIO lines gpio-pch - for the EG20T GPIO lines I can see the PCH GPIO lines in /sys/class/gpio, but not the CPU lines: # dmesg | grep -i gpio pch_gpio 0000:03:00.2: enabling device (0000 -> 0002) gpiochip_find_base: found new base at 244 gpiochip_add: registered GPIOs 244 to 255 on device: 0000:03:00.2 gpiochip_add: registered GPIOs 0 to 4 on device: sch_gpio_core gpiochip_add: registered GPIOs 5 to 13 on device: sch_gpio_resume gpio_request: gpio-0 (sysfs) status -22 gpio_request: gpio-243 (sysfs) status -22 gpio_request: gpio-256 (sysfs) status -22 # ls /sys/class/gpio export gpiochip244 unexport I can export 244-255 and manipulate and read them through the sys interface. I cannot seem to access 0-13, although the dmesg above seems to have successfully added them (and the core/resume pin mapping is correct for a TunnelCreek CPU). I'm not seeing any obvious difference in how the two drivers probe and setup the chip that explains why one is accessible and the other is not. I've enabled the following GPIO CONFIG* options: $ cat config-minnow.gpio | grep -e "^CONFIG_.*GPIO" CONFIG_GENERIC_GPIO=y CONFIG_KEYBOARD_GPIO=y CONFIG_KEYBOARD_GPIO_POLLED=y CONFIG_SPI_GPIO=y CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB=y CONFIG_GPIOLIB=y CONFIG_DEBUG_GPIO=y CONFIG_GPIO_SYSFS=y CONFIG_GPIO_GENERIC=y CONFIG_GPIO_GENERIC_PLATFORM=y CONFIG_GPIO_SCH=y CONFIG_GPIO_PCH=y CONFIG_LEDS_GPIO=y I'm working with 3.4.26, but I have not seen anything in the gpio-sch.c driver commit log that would suggest a fix has landed. I suspect I am missing something fundamental about how these lines get exported. Any ideas on what I might be missing? Is it that some other driver has claimed these GPIO lines? If so, how do I determine which one? Thanks! -- Darren Hart Intel Open Source Technology Center Yocto Project - Technical Lead - Linux Kernel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
