1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * cpld-gpio-bus.c: provides support for the CPLD GPIO bus found on some LaCie 4 * boards (as the 2Big/5Big Network v2 and the 2Big NAS). This parallel GPIO 5 * bus exposes two registers (address and data). Each of this register is made 6 * up of several dedicated GPIOs. An extra GPIO is used to notify the CPLD that 7 * the registers have been updated. 8 * 9 * Mostly this bus is used to configure the LEDs on LaCie boards. 10 * 11 * Copyright (C) 2013 Simon Guinot <simon.guinot (at) sequanux.org> 12 */ 13 14 #include <asm/arch/gpio.h> 15 #include "cpld-gpio-bus.h" 16 17 static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr) 18 { 19 int pin; 20 21 for (pin = 0; pin < bus->num_addr; pin++) 22 kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1); 23 } 24 25 static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data) 26 { 27 int pin; 28 29 for (pin = 0; pin < bus->num_data; pin++) 30 kw_gpio_set_value(bus->data[pin], (data >> pin) & 1); 31 } 32 33 static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus) 34 { 35 /* The transfer is enabled on the raising edge. */ 36 kw_gpio_set_value(bus->enable, 0); 37 kw_gpio_set_value(bus->enable, 1); 38 } 39 40 void cpld_gpio_bus_write(struct cpld_gpio_bus *bus, 41 unsigned addr, unsigned value) 42 { 43 cpld_gpio_bus_set_addr(bus, addr); 44 cpld_gpio_bus_set_data(bus, value); 45 cpld_gpio_bus_enable_select(bus); 46 } 47
