leds-netxbig.c

/*
 * leds-netxbig.c - Driver for the 2Big and 5Big Network series LEDs
 *
 * Copyright (C) 2010 LaCie
 *
 * Author: Simon Guinot <sguinot@lacie.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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/module.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/leds.h>
#include <linux/platform_data/leds-kirkwood-netxbig.h>

/*
 * GPIO extension bus.
 */

static DEFINE_SPINLOCK(gpio_ext_lock);

static void gpio_ext_set_addr(struct netxbig_gpio_ext *gpio_ext, int addr)
{
	int pin;

	for (pin = 0; pin < gpio_ext->num_addr; pin++)
		gpio_set_value(gpio_ext->addr[pin], (addr >> pin) & 1);
}

static void gpio_ext_set_data(struct netxbig_gpio_ext *gpio_ext, int data)
{
	int pin;

	for (pin = 0; pin < gpio_ext->num_data; pin++)
		gpio_set_value(gpio_ext->data[pin], (data >> pin) & 1);
}

static void gpio_ext_enable_select(struct netxbig_gpio_ext *gpio_ext)
{
	/* Enable select is done on the raising edge. */
	gpio_set_value(gpio_ext->enable, 0);
	gpio_set_value(gpio_ext->enable, 1);
}

static void gpio_ext_set_value(struct netxbig_gpio_ext *gpio_ext,
			       int addr, int value)
{
	unsigned long flags;

	spin_lock_irqsave(&gpio_ext_lock, flags);
	gpio_ext_set_addr(gpio_ext, addr);
	gpio_ext_set_data(gpio_ext, value);
	gpio_ext_enable_select(gpio_ext);