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.
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Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
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
...
Broadcom introduced new bus as replacement for older SSB. It is based on AMBA,
however from programming point of view there is nothing AMBA specific we use.
Standard AMBA drivers are platform specific, have hardcoded addresses and use
AMBA standard fields like CID and PID.
In case of Broadcom's cards every device consists of:
1) Broadcom specific AMBA device. It is put on AMBA bus, but can not be treated
as standard AMBA device. Reading it's CID or PID can cause machine lockup.
2) AMBA standard devices called ports or wrappers. They have CIDs (AMBA_CID)
and PIDs (0x103BB369), but we do not use that info for anything. One of that
devices is used for managing Broadcom specific core.
Addresses of AMBA devices are not hardcoded in driver and have to be read from
EPROM.
In this situation we decided to introduce separated bus. It can contain up to
16 devices identified by Broadcom specific fields: manufacturer, id, revision
and class.
58cf279aca