| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 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. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA |
| */ |
| |
| #ifndef _DEVICE_I2C_H_ |
| #define _DEVICE_I2C_H_ |
| |
| #include <stdint.h> |
| #include <stdlib.h> |
| |
| struct i2c_seg |
| { |
| int read; |
| uint8_t chip; |
| uint8_t *buf; |
| int len; |
| }; |
| |
| int platform_i2c_transfer(unsigned bus, struct i2c_seg *segments, int count); |
| |
| #define SOFTWARE_I2C_MAX_BUS 10 /* increase as necessary */ |
| |
| struct software_i2c_ops { |
| void (*set_sda)(unsigned bus, int high); |
| void (*set_scl)(unsigned bus, int high); |
| int (*get_sda)(unsigned bus); |
| int (*get_scl)(unsigned bus); |
| }; |
| |
| extern struct software_i2c_ops *software_i2c[]; |
| |
| int software_i2c_transfer(unsigned bus, struct i2c_seg *segments, int count); |
| void software_i2c_wedge_ack(unsigned bus, u8 chip); |
| void software_i2c_wedge_read(unsigned bus, u8 chip, u8 reg, int bit_count); |
| void software_i2c_wedge_write(unsigned bus, u8 chip, u8 reg, int bit_count); |
| |
| /* |
| * software_i2c is supposed to be a debug feature. It's usually not compiled in, |
| * but when it is it can be dynamically enabled at runtime for certain busses. |
| * Need this ugly stub to arbitrate since I2C device drivers hardcode |
| * 'i2c_transfer()' as their entry point. |
| */ |
| static inline int i2c_transfer(unsigned bus, struct i2c_seg *segments, |
| int count) |
| { |
| if (CONFIG_SOFTWARE_I2C) |
| if (bus < SOFTWARE_I2C_MAX_BUS && software_i2c[bus]) |
| return software_i2c_transfer(bus, segments, count); |
| |
| return platform_i2c_transfer(bus, segments, count); |
| } |
| |
| /* |
| * Read a raw chunk of data in one segment and one frame. |
| * |
| * [start][slave addr][r][data][stop] |
| */ |
| static inline int i2c_read_raw(unsigned bus, uint8_t chip, uint8_t *data, |
| int len) |
| { |
| struct i2c_seg seg = |
| { .read = 1, .chip = chip, .buf = data, .len = len }; |
| return i2c_transfer(bus, &seg, 1); |
| } |
| |
| /* |
| * Write a raw chunk of data in one segment and one frame. |
| * |
| * [start][slave addr][w][data][stop] |
| */ |
| static inline int i2c_write_raw(unsigned bus, uint8_t chip, uint8_t *data, |
| int len) |
| { |
| struct i2c_seg seg = |
| { .read = 0, .chip = chip, .buf = data, .len = len }; |
| return i2c_transfer(bus, &seg, 1); |
| } |
| |
| /** |
| * Read a byte with two segments in one frame |
| * |
| * [start][slave addr][w][register addr][start][slave addr][r][data][stop] |
| */ |
| static inline int i2c_readb(unsigned bus, uint8_t chip, uint8_t reg, |
| uint8_t *data) |
| { |
| struct i2c_seg seg[2]; |
| |
| seg[0].read = 0; |
| seg[0].chip = chip; |
| seg[0].buf = ® |
| seg[0].len = 1; |
| seg[1].read = 1; |
| seg[1].chip = chip; |
| seg[1].buf = data; |
| seg[1].len = 1; |
| |
| return i2c_transfer(bus, seg, ARRAY_SIZE(seg)); |
| } |
| |
| /** |
| * Write a byte with one segment in one frame. |
| * |
| * [start][slave addr][w][register addr][data][stop] |
| */ |
| static inline int i2c_writeb(unsigned bus, uint8_t chip, uint8_t reg, |
| uint8_t data) |
| { |
| struct i2c_seg seg; |
| uint8_t buf[] = {reg, data}; |
| |
| seg.read = 0; |
| seg.chip = chip; |
| seg.buf = buf; |
| seg.len = ARRAY_SIZE(buf); |
| |
| return i2c_transfer(bus, &seg, 1); |
| } |
| |
| #endif /* _DEVICE_I2C_H_ */ |