1*d5cc3f52SSimon Guinot /* 2*d5cc3f52SSimon Guinot * cpld-gpio-bus.c: provides support for the CPLD GPIO bus found on some LaCie 3*d5cc3f52SSimon Guinot * boards (as the 2Big/5Big Network v2 and the 2Big NAS). This parallel GPIO 4*d5cc3f52SSimon Guinot * bus exposes two registers (address and data). Each of this register is made 5*d5cc3f52SSimon Guinot * up of several dedicated GPIOs. An extra GPIO is used to notify the CPLD that 6*d5cc3f52SSimon Guinot * the registers have been updated. 7*d5cc3f52SSimon Guinot * 8*d5cc3f52SSimon Guinot * Mostly this bus is used to configure the LEDs on LaCie boards. 9*d5cc3f52SSimon Guinot * 10*d5cc3f52SSimon Guinot * Copyright (C) 2013 Simon Guinot <simon.guinot@sequanux.org> 11*d5cc3f52SSimon Guinot * 12*d5cc3f52SSimon Guinot * This program is free software; you can redistribute it and/or 13*d5cc3f52SSimon Guinot * modify it under the terms of the GNU General Public License as 14*d5cc3f52SSimon Guinot * published by the Free Software Foundation; either version 2 of 15*d5cc3f52SSimon Guinot * the License, or (at your option) any later version. 16*d5cc3f52SSimon Guinot */ 17*d5cc3f52SSimon Guinot 18*d5cc3f52SSimon Guinot #include <asm/arch/gpio.h> 19*d5cc3f52SSimon Guinot #include "cpld-gpio-bus.h" 20*d5cc3f52SSimon Guinot 21*d5cc3f52SSimon Guinot static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr) 22*d5cc3f52SSimon Guinot { 23*d5cc3f52SSimon Guinot int pin; 24*d5cc3f52SSimon Guinot 25*d5cc3f52SSimon Guinot for (pin = 0; pin < bus->num_addr; pin++) 26*d5cc3f52SSimon Guinot kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1); 27*d5cc3f52SSimon Guinot } 28*d5cc3f52SSimon Guinot 29*d5cc3f52SSimon Guinot static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data) 30*d5cc3f52SSimon Guinot { 31*d5cc3f52SSimon Guinot int pin; 32*d5cc3f52SSimon Guinot 33*d5cc3f52SSimon Guinot for (pin = 0; pin < bus->num_data; pin++) 34*d5cc3f52SSimon Guinot kw_gpio_set_value(bus->data[pin], (data >> pin) & 1); 35*d5cc3f52SSimon Guinot } 36*d5cc3f52SSimon Guinot 37*d5cc3f52SSimon Guinot static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus) 38*d5cc3f52SSimon Guinot { 39*d5cc3f52SSimon Guinot /* The transfer is enabled on the raising edge. */ 40*d5cc3f52SSimon Guinot kw_gpio_set_value(bus->enable, 0); 41*d5cc3f52SSimon Guinot kw_gpio_set_value(bus->enable, 1); 42*d5cc3f52SSimon Guinot } 43*d5cc3f52SSimon Guinot 44*d5cc3f52SSimon Guinot void cpld_gpio_bus_write(struct cpld_gpio_bus *bus, 45*d5cc3f52SSimon Guinot unsigned addr, unsigned value) 46*d5cc3f52SSimon Guinot { 47*d5cc3f52SSimon Guinot cpld_gpio_bus_set_addr(bus, addr); 48*d5cc3f52SSimon Guinot cpld_gpio_bus_set_data(bus, value); 49*d5cc3f52SSimon Guinot cpld_gpio_bus_enable_select(bus); 50*d5cc3f52SSimon Guinot } 51