Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

[POWERPC] Implement support for the GPIO LIB API

Browse source 
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>
This commit is contained in:
Anton Vorontsov 2008-04-11 23:06:36 +10:00 committed by Paul Mackerras
parent 863fbf4966
commit b7ce341585
3 changed files with 113 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

52
Documentation/powerpc/booting-without-of.txt
View file

@ -88,6 +88,10 @@ Table of Contents
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 @@ encodings listed below:
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
========================================

5
arch/powerpc/Kconfig
View file

@ -81,6 +81,11 @@ config GENERIC_FIND_NEXT_BIT
bool
default y
config GENERIC_GPIO
bool
help
Generic GPIO API support
config ARCH_NO_VIRT_TO_BUS
def_bool PPC64

56
include/asm-powerpc/gpio.h Normal file
View file

@ -0,0 +1,56 @@
/*
* Generic GPIO API implementation for PowerPC.
*
* Copyright (c) 2007-2008 MontaVista Software, Inc.
*
* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#ifndef __ASM_POWERPC_GPIO_H
#define __ASM_POWERPC_GPIO_H
#include <linux/errno.h>
#include <asm-generic/gpio.h>
#ifdef CONFIG_HAVE_GPIO_LIB
/*
* We don't (yet) implement inlined/rapid versions for on-chip gpios.
* Just call gpiolib.
*/
static inline int gpio_get_value(unsigned int gpio)
{
return __gpio_get_value(gpio);
}
static inline void gpio_set_value(unsigned int gpio, int value)
{
__gpio_set_value(gpio, value);
}
static inline int gpio_cansleep(unsigned int gpio)
{
return __gpio_cansleep(gpio);
}
/*
* Not implemented, yet.
*/
static inline int gpio_to_irq(unsigned int gpio)
{
return -ENOSYS;
}
static inline int irq_to_gpio(unsigned int irq)
{
return -EINVAL;
}
#endif /* CONFIG_HAVE_GPIO_LIB */
#endif /* __ASM_POWERPC_GPIO_H */