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 * SPDX-License-Identifier: GPL-2.0+ 13 */ 14 15 #include <asm/arch/gpio.h> 16 #include "cpld-gpio-bus.h" 17 18 static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr) 19 { 20 int pin; 21 22 for (pin = 0; pin < bus->num_addr; pin++) 23 kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1); 24 } 25 26 static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data) 27 { 28 int pin; 29 30 for (pin = 0; pin < bus->num_data; pin++) 31 kw_gpio_set_value(bus->data[pin], (data >> pin) & 1); 32 } 33 34 static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus) 35 { 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); 39 } 40 41 void cpld_gpio_bus_write(struct cpld_gpio_bus *bus, 42 unsigned addr, unsigned value) 43 { 44 cpld_gpio_bus_set_addr(bus, addr); 45 cpld_gpio_bus_set_data(bus, value); 46 cpld_gpio_bus_enable_select(bus); 47 } 48