linux/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt
Tony Lindgren 3e6cee1786 pinctrl: single: Add support for wake-up interrupts
The pin control registers can have interrupts for example
for device wake-up. These interrupts can be treated as a
chained interrupt controller as suggested earlier by
Linus Walleij <linus.walleij@linaro.org>.

This patch adds support for interrupts in a way that
should be pretty generic, and works for the omaps that
support wake-up interrupts. On omaps, there's an
interrupt enable and interrupt status bit for each pin.
The two pinctrl domains on omaps share a single interrupt
from the PRM chained interrupt handler. Support for
other similar hardware should be easy to add.

Note that this patch does not attempt to handle the
wake-up interrupts automatically unlike the earlier
patches. This patch allows the device drivers to do
a request_irq() on the wake-up pins as needed. I'll
try to do also a separate generic patch for handling
the wake-up events automatically.

Also note that as this patch makes the pinctrl-single
an irq controller, the current bindings need some
extra trickery to use interrupts from two different
interrupt controllers for the same driver. So it
might be worth waiting a little on the patches
enabling the wake-up interrupts from drivers as there
should be a generic way to handle it coming. And also
there's been discussion of interrupts-extended binding
for using interrupts from multiple interrupt controllers.

In any case, this patch should be ready to go allowing
handling the wake-up interrupts in a generic way, or
separately from the device drivers.

Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Prakash Manjunathappa <prakash.pm@ti.com>
Cc: Roger Quadros <rogerq@ti.com>
Cc: linux-kernel@vger.kernel.org
Cc: Benoît Cousson <bcousson@baylibre.com>
Cc: devicetree@vger.kernel.org
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2013-10-10 15:30:30 -07:00

246 lines
7.6 KiB
Plaintext

One-register-per-pin type device tree based pinctrl driver
Required properties:
- compatible : "pinctrl-single" or "pinconf-single".
"pinctrl-single" means that pinconf isn't supported.
"pinconf-single" means that generic pinconf is supported.
- reg : offset and length of the register set for the mux registers
- pinctrl-single,register-width : pinmux register access width in bits
- pinctrl-single,function-mask : mask of allowed pinmux function bits
in the pinmux register
Optional properties:
- pinctrl-single,function-off : function off mode for disabled state if
available and same for all registers; if not specified, disabling of
pin functions is ignored
- pinctrl-single,bit-per-mux : boolean to indicate that one register controls
more than one pin, for which "pinctrl-single,function-mask" property specifies
position mask of pin.
- pinctrl-single,drive-strength : array of value that are used to configure
drive strength in the pinmux register. They're value of drive strength
current and drive strength mask.
/* drive strength current, mask */
pinctrl-single,power-source = <0x30 0xf0>;
- pinctrl-single,bias-pullup : array of value that are used to configure the
input bias pullup in the pinmux register.
/* input, enabled pullup bits, disabled pullup bits, mask */
pinctrl-single,bias-pullup = <0 1 0 1>;
- pinctrl-single,bias-pulldown : array of value that are used to configure the
input bias pulldown in the pinmux register.
/* input, enabled pulldown bits, disabled pulldown bits, mask */
pinctrl-single,bias-pulldown = <2 2 0 2>;
* Two bits to control input bias pullup and pulldown: User should use
pinctrl-single,bias-pullup & pinctrl-single,bias-pulldown. One bit means
pullup, and the other one bit means pulldown.
* Three bits to control input bias enable, pullup and pulldown. User should
use pinctrl-single,bias-pullup & pinctrl-single,bias-pulldown. Input bias
enable bit should be included in pullup or pulldown bits.
* Although driver could set PIN_CONFIG_BIAS_DISABLE, there's no property as
pinctrl-single,bias-disable. Because pinctrl single driver could implement
it by calling pulldown, pullup disabled.
- pinctrl-single,input-schmitt : array of value that are used to configure
input schmitt in the pinmux register. In some silicons, there're two input
schmitt value (rising-edge & falling-edge) in the pinmux register.
/* input schmitt value, mask */
pinctrl-single,input-schmitt = <0x30 0x70>;
- pinctrl-single,input-schmitt-enable : array of value that are used to
configure input schmitt enable or disable in the pinmux register.
/* input, enable bits, disable bits, mask */
pinctrl-single,input-schmitt-enable = <0x30 0x40 0 0x70>;
- pinctrl-single,gpio-range : list of value that are used to configure a GPIO
range. They're value of subnode phandle, pin base in pinctrl device, pin
number in this range, GPIO function value of this GPIO range.
The number of parameters is depend on #pinctrl-single,gpio-range-cells
property.
/* pin base, nr pins & gpio function */
pinctrl-single,gpio-range = <&range 0 3 0 &range 3 9 1>;
- interrupt-controller : standard interrupt controller binding if using
interrupts for wake-up events for example. In this case pinctrl-single
is set up as a chained interrupt controller and the wake-up interrupts
can be requested by the drivers using request_irq().
- #interrupt-cells : standard interrupt binding if using interrupts
This driver assumes that there is only one register for each pin (unless the
pinctrl-single,bit-per-mux is set), and uses the common pinctrl bindings as
specified in the pinctrl-bindings.txt document in this directory.
The pin configuration nodes for pinctrl-single are specified as pinctrl
register offset and value pairs using pinctrl-single,pins. Only the bits
specified in pinctrl-single,function-mask are updated. For example, setting
a pin for a device could be done with:
pinctrl-single,pins = <0xdc 0x118>;
Where 0xdc is the offset from the pinctrl register base address for the
device pinctrl register, and 0x118 contains the desired value of the
pinctrl register. See the device example and static board pins example
below for more information.
In case when one register changes more than one pin's mux the
pinctrl-single,bits need to be used which takes three parameters:
pinctrl-single,bits = <0xdc 0x18, 0xff>;
Where 0xdc is the offset from the pinctrl register base address for the
device pinctrl register, 0x18 is the desired value, and 0xff is the sub mask to
be used when applying this change to the register.
Optional sub-node: In case some pins could be configured as GPIO in the pinmux
register, those pins could be defined as a GPIO range. This sub-node is required
by pinctrl-single,gpio-range property.
Required properties in sub-node:
- #pinctrl-single,gpio-range-cells : the number of parameters after phandle in
pinctrl-single,gpio-range property.
range: gpio-range {
#pinctrl-single,gpio-range-cells = <3>;
};
Example:
/* SoC common file */
/* first controller instance for pins in core domain */
pmx_core: pinmux@4a100040 {
compatible = "pinctrl-single";
reg = <0x4a100040 0x0196>;
#address-cells = <1>;
#size-cells = <0>;
#interrupt-cells = <1>;
interrupt-controller;
pinctrl-single,register-width = <16>;
pinctrl-single,function-mask = <0xffff>;
};
/* second controller instance for pins in wkup domain */
pmx_wkup: pinmux@4a31e040 {
compatible = "pinctrl-single";
reg = <0x4a31e040 0x0038>;
#address-cells = <1>;
#size-cells = <0>;
#interrupt-cells = <1>;
interrupt-controller;
pinctrl-single,register-width = <16>;
pinctrl-single,function-mask = <0xffff>;
};
control_devconf0: pinmux@48002274 {
compatible = "pinctrl-single";
reg = <0x48002274 4>; /* Single register */
#address-cells = <1>;
#size-cells = <0>;
pinctrl-single,bit-per-mux;
pinctrl-single,register-width = <32>;
pinctrl-single,function-mask = <0x5F>;
};
/* third controller instance for pins in gpio domain */
pmx_gpio: pinmux@d401e000 {
compatible = "pinconf-single";
reg = <0xd401e000 0x0330>;
#address-cells = <1>;
#size-cells = <1>;
ranges;
pinctrl-single,register-width = <32>;
pinctrl-single,function-mask = <7>;
/* sparse GPIO range could be supported */
pinctrl-single,gpio-range = <&range 0 3 0 &range 3 9 1
&range 12 1 0 &range 13 29 1
&range 43 1 0 &range 44 49 1
&range 94 1 1 &range 96 2 1>;
range: gpio-range {
#pinctrl-single,gpio-range-cells = <3>;
};
};
/* board specific .dts file */
&pmx_core {
/*
* map all board specific static pins enabled by the pinctrl driver
* itself during the boot (or just set them up in the bootloader)
*/
pinctrl-names = "default";
pinctrl-0 = <&board_pins>;
board_pins: pinmux_board_pins {
pinctrl-single,pins = <
0x6c 0xf
0x6e 0xf
0x70 0xf
0x72 0xf
>;
};
uart0_pins: pinmux_uart0_pins {
pinctrl-single,pins = <
0x208 0 /* UART0_RXD (IOCFG138) */
0x20c 0 /* UART0_TXD (IOCFG139) */
>;
pinctrl-single,bias-pulldown = <0 2 2>;
pinctrl-single,bias-pullup = <0 1 1>;
};
/* map uart2 pins */
uart2_pins: pinmux_uart2_pins {
pinctrl-single,pins = <
0xd8 0x118
0xda 0
0xdc 0x118
0xde 0
>;
};
};
&control_devconf0 {
mcbsp1_pins: pinmux_mcbsp1_pins {
pinctrl-single,bits = <
0x00 0x18 0x18 /* FSR/CLKR signal from FSX/CLKX pin */
>;
};
mcbsp2_clks_pins: pinmux_mcbsp2_clks_pins {
pinctrl-single,bits = <
0x00 0x40 0x40 /* McBSP2 CLKS from McBSP_CLKS pin */
>;
};
};
&uart1 {
pinctrl-names = "default";
pinctrl-0 = <&uart0_pins>;
};
&uart2 {
pinctrl-names = "default";
pinctrl-0 = <&uart2_pins>;
};