1 /* 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. 7 * 8 * Mostly this bus is used to configure the LEDs on LaCie boards. 9 * 10 * Copyright (C) 2013 Simon Guinot <simon.guinot@sequanux.org> 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License as 14 * published by the Free Software Foundation; either version 2 of 15 * the License, or (at your option) any later version. 16 */ 17 18 #include <asm/arch/gpio.h> 19 #include "cpld-gpio-bus.h" 20 21 static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr) 22 { 23 int pin; 24 25 for (pin = 0; pin < bus->num_addr; pin++) 26 kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1); 27 } 28 29 static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data) 30 { 31 int pin; 32 33 for (pin = 0; pin < bus->num_data; pin++) 34 kw_gpio_set_value(bus->data[pin], (data >> pin) & 1); 35 } 36 37 static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus) 38 { 39 /* The transfer is enabled on the raising edge. */ 40 kw_gpio_set_value(bus->enable, 0); 41 kw_gpio_set_value(bus->enable, 1); 42 } 43 44 void cpld_gpio_bus_write(struct cpld_gpio_bus *bus, 45 unsigned addr, unsigned value) 46 { 47 cpld_gpio_bus_set_addr(bus, addr); 48 cpld_gpio_bus_set_data(bus, value); 49 cpld_gpio_bus_enable_select(bus); 50 } 51