[U-Boot] [PATCH v3] nios2: add gpio support

[Sergei Shtylyov <sshtylyov@mvista.com>]

Hello.

Thomas Chou wrote:

> This patch adds driver for a trivial gpio core, which is described
> in http://nioswiki.com/GPIO.
>
> When CONFIG_SYS_GPIO_BASE is not defined, board may provide
> its own driver.
>
> Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
> ---
> arch dir reorganized.
>
>  arch/nios2/include/asm/gpio.h |   52 +++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 52 insertions(+), 0 deletions(-)
>  create mode 100644 arch/nios2/include/asm/gpio.h
>
> diff --git a/arch/nios2/include/asm/gpio.h b/arch/nios2/include/asm/gpio.h
> new file mode 100644
> index 0000000..cd2df7d
> --- /dev/null
> +++ b/arch/nios2/include/asm/gpio.h
> @@ -0,0 +1,52 @@
> +/*
> + * nios2 gpio driver
> + *
> + * This gpio core is described in http://nioswiki.com/GPIO
> + * bit[0] data
> + * bit[1] output enable
> + *
> + * when CONFIG_SYS_GPIO_BASE is not defined, board may provide
> + * its own driver.
> + *
> + * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef _ASM_NIOS2_GPIO_H_
> +#define _ASM_NIOS2_GPIO_H_ 1
> +
> +#ifdef CONFIG_SYS_GPIO_BASE
> +#include <asm/io.h>
> +
> +static inline int gpio_direction_input(unsigned gpio)
> +{
> +	writel(1, CONFIG_SYS_GPIO_BASE + ((gpio) << 2));
>   
> +	return 0;
> +}
> +
> +static inline int gpio_direction_output(unsigned gpio, int value)
> +{
> +	writel(value ? 3 : 2, CONFIG_SYS_GPIO_BASE + ((gpio) << 2));
> +	return 0;
> +}
> +
> +static inline int gpio_get_value(unsigned gpio)
> +{
> +	return readl(CONFIG_SYS_GPIO_BASE + ((gpio) << 2));
> +}
> +
> +static inline void gpio_set_value(unsigned gpio, int value)
> +{
> +	writel(value ? 3 : 2, CONFIG_SYS_GPIO_BASE + ((gpio) << 2));
> +}
>   

   Why enclose 'gpio' into () when it's not within a macro?

WBR, Sergei