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/*
* cpld-gpio-bus.c: provides support for the CPLD GPIO bus found on some LaCie
* boards (as the 2Big/5Big Network v2 and the 2Big NAS). This parallel GPIO
* bus exposes two registers (address and data). Each of this register is made
* up of several dedicated GPIOs. An extra GPIO is used to notify the CPLD that
* the registers have been updated.
*
* Mostly this bus is used to configure the LEDs on LaCie boards.
*
* Copyright (C) 2013 Simon Guinot <simon.guinot@sequanux.org>
*
* 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.
*/
#include <asm/arch/gpio.h>
#include "cpld-gpio-bus.h"
static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr)
{
int pin;
for (pin = 0; pin < bus->num_addr; pin++)
kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1);
}
static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data)
{
int pin;
for (pin = 0; pin < bus->num_data; pin++)
kw_gpio_set_value(bus->data[pin], (data >> pin) & 1);
}
static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus)
{
/* The transfer is enabled on the raising edge. */
kw_gpio_set_value(bus->enable, 0);
kw_gpio_set_value(bus->enable, 1);
}
void cpld_gpio_bus_write(struct cpld_gpio_bus *bus,
unsigned addr, unsigned value)
{
cpld_gpio_bus_set_addr(bus, addr);
cpld_gpio_bus_set_data(bus, value);
cpld_gpio_bus_enable_select(bus);
}
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