1*83d290c5STom Rini // SPDX-License-Identifier: GPL-2.0+ 2d5cc3f52SSimon Guinot /* 3d5cc3f52SSimon Guinot * cpld-gpio-bus.c: provides support for the CPLD GPIO bus found on some LaCie 4d5cc3f52SSimon Guinot * boards (as the 2Big/5Big Network v2 and the 2Big NAS). This parallel GPIO 5d5cc3f52SSimon Guinot * bus exposes two registers (address and data). Each of this register is made 6d5cc3f52SSimon Guinot * up of several dedicated GPIOs. An extra GPIO is used to notify the CPLD that 7d5cc3f52SSimon Guinot * the registers have been updated. 8d5cc3f52SSimon Guinot * 9d5cc3f52SSimon Guinot * Mostly this bus is used to configure the LEDs on LaCie boards. 10d5cc3f52SSimon Guinot * 11d5cc3f52SSimon Guinot * Copyright (C) 2013 Simon Guinot <simon.guinot@sequanux.org> 12d5cc3f52SSimon Guinot */ 13d5cc3f52SSimon Guinot 14d5cc3f52SSimon Guinot #include <asm/arch/gpio.h> 15d5cc3f52SSimon Guinot #include "cpld-gpio-bus.h" 16d5cc3f52SSimon Guinot 17d5cc3f52SSimon Guinot static void cpld_gpio_bus_set_addr(struct cpld_gpio_bus *bus, unsigned addr) 18d5cc3f52SSimon Guinot { 19d5cc3f52SSimon Guinot int pin; 20d5cc3f52SSimon Guinot 21d5cc3f52SSimon Guinot for (pin = 0; pin < bus->num_addr; pin++) 22d5cc3f52SSimon Guinot kw_gpio_set_value(bus->addr[pin], (addr >> pin) & 1); 23d5cc3f52SSimon Guinot } 24d5cc3f52SSimon Guinot 25d5cc3f52SSimon Guinot static void cpld_gpio_bus_set_data(struct cpld_gpio_bus *bus, unsigned data) 26d5cc3f52SSimon Guinot { 27d5cc3f52SSimon Guinot int pin; 28d5cc3f52SSimon Guinot 29d5cc3f52SSimon Guinot for (pin = 0; pin < bus->num_data; pin++) 30d5cc3f52SSimon Guinot kw_gpio_set_value(bus->data[pin], (data >> pin) & 1); 31d5cc3f52SSimon Guinot } 32d5cc3f52SSimon Guinot 33d5cc3f52SSimon Guinot static void cpld_gpio_bus_enable_select(struct cpld_gpio_bus *bus) 34d5cc3f52SSimon Guinot { 35d5cc3f52SSimon Guinot /* The transfer is enabled on the raising edge. */ 36d5cc3f52SSimon Guinot kw_gpio_set_value(bus->enable, 0); 37d5cc3f52SSimon Guinot kw_gpio_set_value(bus->enable, 1); 38d5cc3f52SSimon Guinot } 39d5cc3f52SSimon Guinot 40d5cc3f52SSimon Guinot void cpld_gpio_bus_write(struct cpld_gpio_bus *bus, 41d5cc3f52SSimon Guinot unsigned addr, unsigned value) 42d5cc3f52SSimon Guinot { 43d5cc3f52SSimon Guinot cpld_gpio_bus_set_addr(bus, addr); 44d5cc3f52SSimon Guinot cpld_gpio_bus_set_data(bus, value); 45d5cc3f52SSimon Guinot cpld_gpio_bus_enable_select(bus); 46d5cc3f52SSimon Guinot } 47