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    Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio · 58cf279a
    Linus Torvalds authored
    Pull GPIO updates from Linus Walleij:
     "Here is the bulk of GPIO changes for v4.5.
    
      Notably there are big refactorings mostly by myself, aimed at getting
      the gpio_chip into a shape that makes me believe I can proceed to
      preserve state for a proper userspace ABI (character device) that has
      already been proposed once, but resulted in the feedback that I need
      to go back and restructure stuff.  So I've been restructuring stuff.
      On the way I ran into brokenness (return code from the get_value()
      callback) and had to fix it.  Also, refactored generic GPIO to be
      simpler.
    
      Some of that is still waiting to trickle down from the subsystems all
      over the kernel that provide random gpio_chips, I've touched every
      single GPIO driver in the kernel now, oh man I didn't know I was
      responsible for so much...
    
      Apart from that we're churning along as usual.
    
      I took some effort to test and retest so it should merge nicely and we
      shook out a couple of bugs in -next.
    
      Infrastructural changes:
    
       - In struct gpio_chip, rename the .dev node to .parent to better
         reflect the fact that this is not the GPIO struct device
         abstraction.  We will add that soon so this would be totallt
         confusing.
    
       - It was noted that the driver .get_value() callbacks was sometimes
         reporting negative -ERR values to the gpiolib core, expecting them
         to be propagated to consumer gpiod_get_value() and gpio_get_value()
         calls.  This was not happening, so as there was a mess of drivers
         returning negative errors and some returning "anything else than
         zero" to indicate that a line was active.  As some would have bit
         31 set to indicate "line active" it clashed with negative error
         codes.  This is fixed by the largeish series clamping values in all
         drivers with !!value to [0,1] and then augmenting the code to
         propagate error codes to consumers.  (Includes some ACKed patches
         in other subsystems.)
    
       - Add a void *data pointer to struct gpio_chip.  The container_of()
         design pattern is indeed very nice, but we want to reform the
         struct gpio_chip to be a non-volative, stateless business, and keep
         states internal to the gpiolib to be able to hold on to the state
         when adding a proper userspace ABI (character device) further down
         the road.  To achieve this, drivers need a handle at the internal
         state that is not dependent on their struct gpio_chip() so we add
         gpiochip_add_data() and gpiochip_get_data() following the pattern
         of many other subsystems.  All the "use gpiochip data pointer"
         patches transforms drivers to this scheme.
    
       - The Generic GPIO chip header has been merged into the general
         <linux/gpio/driver.h> header, and the custom header for that
         removed.  Instead of having a separate mm_gpio_chip struct for
         these generic drivers, merge that into struct gpio_chip,
         simplifying the code and removing the need for separate and
         confusing includes.
    
      Misc improvements:
    
       - Stabilize the way GPIOs are looked up from the ACPI legacy
         specification.
    
       - Incremental driver features for PXA, PCA953X, Lantiq (patches from
         the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48
    
      New drivers:
    
       - Add a GPIO chip to the ALSA SoC AC97 driver.
    
       - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir,
         but the branch is merged here too to account for infrastructural
         changes).
    
       - The sx150x driver now supports the sx1502"
    
    * tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits)
      gpio: generic: make bgpio_pdata always visible
      gpiolib: fix chip order in gpio list
      gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()
      gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs()
      gpio: brcmstb: Allow building driver for BMIPS_GENERIC
      gpio: brcmstb: Set endian flags for big-endian MIPS
      gpio: moxart: fix build regression
      gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs()
      leds: pca9532: use gpiochip data pointer
      leds: tca6507: use gpiochip data pointer
      hid: cp2112: use gpiochip data pointer
      bcma: gpio: use gpiochip data pointer
      avr32: gpio: use gpiochip data pointer
      video: fbdev: via: use gpiochip data pointer
      gpio: pch: Optimize pch_gpio_get()
      Revert "pinctrl: lantiq: Implement gpio_chip.to_irq"
      pinctrl: nsp-gpio: use gpiochip data pointer
      pinctrl: vt8500-wmt: use gpiochip data pointer
      pinctrl: exynos5440: use gpiochip data pointer
      pinctrl: at91-pio4: use gpiochip data pointer
      ...
    58cf279a