1. 09 Feb, 2016 1 commit
    • Linus Walleij's avatar
      gpio: make the gpiochip a real device · ff2b1359
      Linus Walleij authored
      GPIO chips have been around for years, but were never real devices,
      instead they were piggy-backing on a parent device (such as a
      platform_device or amba_device) but this was always optional.
      GPIO chips could also exist without any device at all, with its
      struct device *parent (ex *dev) pointer being set to null.
      
      When sysfs was in use, a mock device would be created, with the
      optional parent assigned, or just floating orphaned with NULL
      as parent.
      
      If sysfs is active, it will use this device as parent.
      
      We now create a gpio_device struct containing a real
      struct device and move the subsystem over to using that. The
      list of struct gpio_chip:s is augmented to hold struct
      gpio_device:s and we find gpio_chips:s by first looking up
      the struct gpio_device.
      
      The struct gpio_device is designed to stay around even if the
      gpio_chip is removed, so as to satisfy users in userspace
      that need a backing data structure to hold the state of the
      session initiated with e.g. a character device even if there is
      no physical chip anymore.
      
      From this point on, gpiochips are devices.
      
      Cc: Johan Hovold <johan@kernel.org>
      Cc: Michael Welling <mwelling@ieee.org>
      Cc: Markus Pargmann <mpa@pengutronix.de>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      ff2b1359
  2. 24 Jan, 2016 39 commits