diff options
| -rw-r--r-- | Documentation/powerpc/booting-without-of.txt | 52 | ||||
| -rw-r--r-- | arch/powerpc/Kconfig | 5 | ||||
| -rw-r--r-- | include/asm-powerpc/gpio.h | 56 |
3 files changed, 113 insertions, 0 deletions
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 2aafda9254f..528b4822f45 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -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 ======================================== diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 1d4d19f6d6e..c51b6bba5fc 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -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 diff --git a/include/asm-powerpc/gpio.h b/include/asm-powerpc/gpio.h new file mode 100644 index 00000000000..77ad3a890f3 --- /dev/null +++ b/include/asm-powerpc/gpio.h @@ -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 */ |