Re: [PATCH 2/2] [POWERPC] Implement support for the GPIO LIB API

["Grant Likely" <grant.likely@secretlab.ca>]

On Fri, Apr 11, 2008 at 7:06 AM, Anton Vorontsov
<avorontsov@ru.mvista.com> wrote:
> This patch implements support for the GPIO LIB API. Two calls
>  unimplemented though: irq_to_gpio and gpio_to_irq.
>
>  Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>

I like it

Acked-by: Grant Likely <grant.likely@secretlab.ca>

>  ---
>   Documentation/powerpc/booting-without-of.txt |   52 ++++++++++++++++++++++++
>   arch/powerpc/Kconfig                         |    5 ++
>   include/asm-powerpc/gpio.h                   |   56 ++++++++++++++++++++++++++
>   3 files changed, 113 insertions(+), 0 deletions(-)
>   create mode 100644 include/asm-powerpc/gpio.h
>
>  diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
>  index b506245..e9e0c2f 100644
>  --- a/Documentation/powerpc/booting-without-of.txt
>  +++ b/Documentation/powerpc/booting-without-of.txt
>  @@ -66,6 +66,10 @@ 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
>
>
>  @@ -2925,6 +2929,54 @@ 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 0b27cbd..f328509 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 0000000..77ad3a8
>  --- /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 */
>  --
>  1.5.4.5
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>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.