[POWERPC] Implement support for the GPIO LIB API
This implements support for the GPIO LIB API. Two calls are still
unimplemented though: irq_to_gpio and gpio_to_irq.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index 2aafda9..528b482 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -88,6 +88,10 @@
3) OpenPIC Interrupt Controllers
4) ISA Interrupt Controllers
+ VIII - Specifying GPIO information for devices
+ 1) gpios property
+ 2) gpio-controller nodes
+
Appendix A - Sample SOC node for MPC8540
@@ -3431,6 +3435,54 @@
2 = high to low edge sensitive type enabled
3 = low to high edge sensitive type enabled
+VIII - Specifying GPIO information for devices
+==============================================
+
+1) gpios property
+-----------------
+
+Nodes that makes use of GPIOs should define them using `gpios' property,
+format of which is: <&gpio-controller1-phandle gpio1-specifier
+ &gpio-controller2-phandle gpio2-specifier
+ 0 /* holes are permitted, means no GPIO 3 */
+ &gpio-controller4-phandle gpio4-specifier
+ ...>;
+
+Note that gpio-specifier length is controller dependent.
+
+gpio-specifier may encode: bank, pin position inside the bank,
+whether pin is open-drain and whether pin is logically inverted.
+
+Example of the node using GPIOs:
+
+ node {
+ gpios = <&qe_pio_e 18 0>;
+ };
+
+In this example gpio-specifier is "18 0" and encodes GPIO pin number,
+and empty GPIO flags as accepted by the "qe_pio_e" gpio-controller.
+
+2) gpio-controller nodes
+------------------------
+
+Every GPIO controller node must have #gpio-cells property defined,
+this information will be used to translate gpio-specifiers.
+
+Example of two SOC GPIO banks defined as gpio-controller nodes:
+
+ qe_pio_a: gpio-controller@1400 {
+ #gpio-cells = <2>;
+ compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
+ reg = <0x1400 0x18>;
+ gpio-controller;
+ };
+
+ qe_pio_e: gpio-controller@1460 {
+ #gpio-cells = <2>;
+ compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank";
+ reg = <0x1460 0x18>;
+ gpio-controller;
+ };
Appendix A - Sample SOC node for MPC8540
========================================