2 * cpld-gpio-bus.c: provides support for the CPLD GPIO bus found on some LaCie
3 * boards (as the 2Big/5Big Network v2 and the 2Big NAS). This parallel GPIO
4 * bus exposes two registers (address and data). Each of this register is made
5 * up of several dedicated GPIOs. An extra GPIO is used to notify the CPLD that
6 * the registers have been updated.
8 * Mostly this bus is used to configure the LEDs on LaCie boards.
10 * Copyright (C) 2013 Simon Guinot <simon.guinot@sequanux.org>
12 * SPDX-License-Identifier: GPL-2.0+
15 #include <asm/arch/gpio.h>
16 #include "cpld-gpio-bus.h"
18 static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr)
22 for (pin = 0; pin < bus->num_addr; pin++)
23 kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1);
26 static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data)
30 for (pin = 0; pin < bus->num_data; pin++)
31 kw_gpio_set_value(bus->data[pin], (data >> pin) & 1);
34 static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus)
36 /* The transfer is enabled on the raising edge. */
37 kw_gpio_set_value(bus->enable, 0);
38 kw_gpio_set_value(bus->enable, 1);
41 void cpld_gpio_bus_write(struct cpld_gpio_bus *bus,
42 unsigned addr, unsigned value)
44 cpld_gpio_bus_set_addr(bus, addr);
45 cpld_gpio_bus_set_data(bus, value);
46 cpld_gpio_bus_enable_select(bus);