/* * This file is part of the coreboot project. * * Copyright 2014 Google Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #ifndef __SRC_INCLUDE_GPIO_H__ #define __SRC_INCLUDE_GPIO_H__ #include <soc/gpio.h> #include <types.h> /* <soc/gpio.h> must typedef a gpio_t that fits in 32 bits. */ _Static_assert(sizeof(gpio_t) <= sizeof(u32), "gpio_t doesn't fit in lb_gpio"); /* The following functions must be implemented by SoC/board code. */ int gpio_get(gpio_t gpio); void gpio_set(gpio_t gpio, int value); void gpio_input_pulldown(gpio_t gpio); void gpio_input_pullup(gpio_t gpio); void gpio_input(gpio_t gpio); void gpio_output(gpio_t gpio, int value); int _gpio_base3_value(gpio_t gpio[], int num_gpio, int binary_first); /* * This function may be implemented by SoC/board code to provide * a mapping from a GPIO pin to controller by returning the ACPI * path for the controller that owns this GPIO. * * If not implemented the default handler will return NULL. */ const char *gpio_acpi_path(gpio_t gpio); /* * This function may be implemented by SoC/board code to provide * a mapping from the internal representation of a GPIO to the 16bit * value used in an ACPI GPIO pin table entry. * * If not implemented by the SOC the default handler will return 0 * because the underlying type of gpio_t is unknown. */ uint16_t gpio_acpi_pin(gpio_t gpio); /* * Read the value presented by the set of GPIOs, when each pin is interpreted * as a base-2 digit (LOW = 0, HIGH = 1). * * gpio[]: pin positions to read. gpio[0] is less significant than gpio[1]. * num_gpio: number of pins to read. * * There are also pulldown and pullup variants which default each gpio to * be configured with an internal pulldown and pullup, respectively. */ int gpio_base2_value(gpio_t gpio[], int num_gpio); int gpio_pulldown_base2_value(gpio_t gpio[], int num_gpio); int gpio_pullup_base2_value(gpio_t gpio[], int num_gpio); /* * Read the value presented by the set of GPIOs, when each pin is interpreted * as a base-3 digit (LOW = 0, HIGH = 1, Z/floating = 2). * Example: X1 = Z, X2 = 1 -> gpio_base3_value({GPIO(X1), GPIO(X2)}) = 5 * BASE3() from <base3.h> can generate numbers to compare the result to. * * gpio[]: pin positions to read. gpio[0] is less significant than gpio[1]. * num_gpio: number of pins to read. */ static inline int gpio_base3_value(gpio_t gpio[], int num_gpio) { return _gpio_base3_value(gpio, num_gpio, 0); } /* * Read the value presented by the set of GPIOs, when each pin is interpreted * as a base-3 digit (LOW = 0, HIGH = 1, Z/floating = 2) in a non-standard * ternary number system where the first 2^n natural numbers are represented * as they would be in a binary system (without any Z digits), and the following * 3^n-2^n numbers use the remaining ternary representations in the normal * ternary system order (skipping the values that were already used up). * This is useful for boards which initially used a binary board ID and later * decided to switch to tri-state after some revisions have already been built. * Example: For num_gpio = 2 we get the following representation: * * Number X1 X0 * 0 0 0 * 1 0 1 * 2 1 0 * 3 1 1 // Start counting ternaries back at 0 after this * 4 0 2 // Skipping 00 and 01 which are already used up * 5 1 2 // Skipping 10 and 11 which are already used up * 6 2 0 * 7 2 1 * 8 2 2 * * gpio[]: pin positions to read. gpio[0] is less significant than gpio[1]. * num_gpio: number of pins to read. */ static inline int gpio_binary_first_base3_value(gpio_t gpio[], int num_gpio) { return _gpio_base3_value(gpio, num_gpio, 1); } #endif /* __SRC_INCLUDE_GPIO_H__ */