Commit e1b2dc70 authored by Simon Arlott's avatar Simon Arlott Committed by Linus Walleij

pinctrl: add bcm2835 driver

The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt
controller, and pinmux/control device.

Original driver by Simon Arlott.
Rewrite including GPIO chip device by Chris Boot.

Upstreaming changes by Stephen Warren:
* Wrote DT binding documentation.
* Changed brcm,function to an integer to more directly match the
  datasheet, and to match brcm,pins being an integer.
* Implemented pull-up/down pin config.
* Removed read-only DT property and related code. The restriction this
  implemented are driven by the board, not the GPIO HW block, so don't
  really make sense of a HW block binding, were in general incomplete
  (since they could only know about the few pins hard-coded into the
  Raspberry Pi B board design and not the uncommitted GPIOS), and are
  better represented simply by not writing incorrect data into pin
  configuration nodes.
* Don't set GPIO_IN function select in gpio_request_enable() to avoid
  glitches; defer this to gpio_set_direction(). Consequently, removed
  empty bcm2835_pmx_gpio_request_enable().
* Simplified enabled_irq_map[]; make it explicitly 1 entry per bank.
* Lifted use of enabled_irq_map[] outside the per-interrupt loop in
  IRQ handler, thus fixing an issue where the code was indexing into
  enabled_irq_map[] by intra-bank GPIO ID, not global GPIO ID.
* Removed locking in IRQ handler, since all other code uses
  spin_lock_irqsave() and so guarantees it doesn't run concurrently
  with the handler.
* Moved duplicated BUILD_BUG_ON()s into probe(). Also check size of
  bcm2835_gpio_pins[].
* Remove range-checking from bcm2835_pctl_get_groups_count() since we've
  decided to trust the pinctrl core.
* Made bcm2835_pmx_gpio_disable_free() call bcm2835_pinctrl_fsel_set()
  directly for simplicity.
* Fixed body of dt_free_map() to match latest dt_node_to_map().
* Removed GPIO ownership check from bcm2835_pmx_enable() since the pinctrl
  core owns doing this.
* Made irq_chip and pinctrl_gpio_range .name == MODULE_NAME so it's more
  descriptive.
* Simplified remove(); removed call to non-existent
  pinctrl_remove_gpio_range(), remove early return on error.
* Don't force gpiochip's base to 0. Set gpio_range.base to gpiochip's
  base GPIO number.
* Error-handling cleanups in probe().
* Switched to module_platform_driver() rather than open-coding.
* Made pin, group, and function names lower-case.
* s/broadcom/brcm/ in DT property names.
* s/2708/2835/.
* Fixed a couple minor checkpatch warnings, and other minor cleanup.
Signed-off-by: default avatarSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: default avatarChris Boot <bootc@bootc.net>
Signed-off-by: default avatarStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij's avatarLinus Walleij <linus.walleij@linaro.org>
parent b0e181d0
Broadcom BCM2835 GPIO (and pinmux) controller
The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt
controller, and pinmux/control device.
Required properties:
- compatible: "brcm,bcm2835-gpio"
- reg: Should contain the physical address of the GPIO module's registes.
- gpio-controller: Marks the device node as a GPIO controller.
- #gpio-cells : Should be two. The first cell is the pin number and the
second cell is used to specify optional parameters:
- bit 0 specifies polarity (0 for normal, 1 for inverted)
- interrupts : The interrupt outputs from the controller. One interrupt per
individual bank followed by the "all banks" interrupt.
- interrupt-controller: Marks the device node as an interrupt controller.
- #interrupt-cells : Should be 2.
The first cell is the GPIO number.
The second cell is used to specify flags:
bits[3:0] trigger type and level flags:
1 = low-to-high edge triggered.
2 = high-to-low edge triggered.
4 = active high level-sensitive.
8 = active low level-sensitive.
Valid combinations are 1, 2, 3, 4, 8.
Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
Please refer to pinctrl-bindings.txt in this directory for details of the
common pinctrl bindings used by client devices, including the meaning of the
phrase "pin configuration node".
Each pin configuration node lists the pin(s) to which it applies, and one or
more of the mux function to select on those pin(s), and pull-up/down
configuration. Each subnode only affects those parameters that are explicitly
listed. In other words, a subnode that lists only a mux function implies no
information about any pull configuration. Similarly, a subnode that lists only
a pul parameter implies no information about the mux function.
Required subnode-properties:
- brcm,pins: An array of cells. Each cell contains the ID of a pin. Valid IDs
are the integer GPIO IDs; 0==GPIO0, 1==GPIO1, ... 53==GPIO53.
Optional subnode-properties:
- brcm,function: Integer, containing the function to mux to the pin(s):
0: GPIO in
1: GPIO out
2: alt5
3: alt4
4: alt0
5: alt1
6: alt2
7: alt3
- brcm,pull: Integer, representing the pull-down/up to apply to the pin(s):
0: none
1: down
2: up
Each of brcm,function and brcm,pull may contain either a single value which
will be applied to all pins in brcm,pins, or 1 value for each entry in
brcm,pins.
Example:
gpio: gpio {
compatible = "brcm,bcm2835-gpio";
reg = <0x2200000 0xb4>;
interrupts = <2 17>, <2 19>, <2 18>, <2 20>;
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
};
......@@ -26,6 +26,11 @@ config DEBUG_PINCTRL
help
Say Y here to add some extra checks and diagnostics to PINCTRL calls.
config PINCTRL_BCM2835
bool
select PINMUX
select PINCONF
config PINCTRL_IMX
bool
select PINMUX
......
......@@ -9,6 +9,7 @@ ifeq ($(CONFIG_OF),y)
obj-$(CONFIG_PINCTRL) += devicetree.o
endif
obj-$(CONFIG_GENERIC_PINCONF) += pinconf-generic.o
obj-$(CONFIG_PINCTRL_BCM2835) += pinctrl-bcm2835.o
obj-$(CONFIG_PINCTRL_IMX) += pinctrl-imx.o
obj-$(CONFIG_PINCTRL_IMX35) += pinctrl-imx35.o
obj-$(CONFIG_PINCTRL_IMX51) += pinctrl-imx51.o
......
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