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Diffstat (limited to 'src/include/device/i2c_simple.h')
| -rw-r--r-- | src/include/device/i2c_simple.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/include/device/i2c_simple.h b/src/include/device/i2c_simple.h new file mode 100644 index 0000000000..dcde601994 --- /dev/null +++ b/src/include/device/i2c_simple.h @@ -0,0 +1,157 @@ +/* + * 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. + */ + +#ifndef _DEVICE_I2C_SIMPLE_H_ +#define _DEVICE_I2C_SIMPLE_H_ + +#include <commonlib/helpers.h> +#include <device/i2c.h> + +int platform_i2c_transfer(unsigned int bus, struct i2c_msg *segments, + int count); + +#define SOFTWARE_I2C_MAX_BUS 10 /* increase as necessary */ + +struct software_i2c_ops { + void (*set_sda)(unsigned int bus, int high); + void (*set_scl)(unsigned int bus, int high); + int (*get_sda)(unsigned int bus); + int (*get_scl)(unsigned int bus); +}; + +extern struct software_i2c_ops *software_i2c[]; + +int software_i2c_transfer(unsigned int bus, struct i2c_msg *segments, + int count); +void software_i2c_wedge_ack(unsigned int bus, u8 slave); +void software_i2c_wedge_read(unsigned int bus, u8 slave, u8 reg, int bit_count); +void software_i2c_wedge_write(unsigned int bus, u8 slave, u8 reg, + int bit_count); + +int i2c_read_field(unsigned int bus, uint8_t slave, uint8_t reg, uint8_t *data, + uint8_t mask, uint8_t shift); +int i2c_write_field(unsigned int bus, uint8_t slave, uint8_t reg, uint8_t data, + uint8_t mask, uint8_t shift); + +/* + * 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 int bus, struct i2c_msg *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 int bus, uint8_t slave, uint8_t *data, + int len) +{ + struct i2c_msg seg = { + .flags = I2C_M_RD, .slave = slave, .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 int bus, uint8_t slave, uint8_t *data, + int len) +{ + struct i2c_msg seg = { + .flags = 0, .slave = slave, .buf = data, .len = len + }; + + return i2c_transfer(bus, &seg, 1); +} + +/** + * Read multi-bytes with two segments in one frame + * + * [start][slave addr][w][register addr][start][slave addr][r][data...][stop] + */ +static inline int i2c_read_bytes(unsigned int bus, uint8_t slave, uint8_t reg, + uint8_t *data, int len) +{ + struct i2c_msg seg[2]; + + seg[0].flags = 0; + seg[0].slave = slave; + seg[0].buf = ® + seg[0].len = 1; + seg[1].flags = I2C_M_RD; + seg[1].slave = slave; + seg[1].buf = data; + seg[1].len = len; + + return i2c_transfer(bus, seg, ARRAY_SIZE(seg)); +} + +/** + * 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 int bus, uint8_t slave, uint8_t reg, + uint8_t *data) +{ + struct i2c_msg seg[2]; + + seg[0].flags = 0; + seg[0].slave = slave; + seg[0].buf = ® + seg[0].len = 1; + seg[1].flags = I2C_M_RD; + seg[1].slave = slave; + 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 int bus, uint8_t slave, uint8_t reg, + uint8_t data) +{ + struct i2c_msg seg; + uint8_t buf[] = {reg, data}; + + seg.flags = 0; + seg.slave = slave; + seg.buf = buf; + seg.len = ARRAY_SIZE(buf); + + return i2c_transfer(bus, &seg, 1); +} + +#endif /* _DEVICE_I2C_SIMPLE_H_ */ |