include/i2c.h

   1 /*
   2  * Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
   3  * Copyright (C) 2009 - 2013 Heiko Schocher <hs@denx.de>
   4  * Changes for multibus/multiadapter I2C support.
   5  *
   6  * (C) Copyright 2001
   7  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  *
  11  * The original I2C interface was
  12  *   (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
  13  *   AIRVENT SAM s.p.a - RIMINI(ITALY)
  14  * but has been changed substantially.
  15  */
  16
  17 #ifndef _I2C_H_
  18 #define _I2C_H_
  19
  20 /*
  21  * Configuration items.
  22  */
  23 /* TODO: config.h? */
  24 #define I2C_RXTX_LEN    128     /* maximum tx/rx buffer length */
  25
  26
  27 /*
  28  * Initialization, must be called once on start up, may be called
  29  * repeatedly to change the speed.
  30  */
  31 void i2c_init(uint32_t speed);
  32
  33 /*
  34  * Probe the given I2C chip address.  Returns 0 if a chip responded,
  35  * not 0 on failure.
  36  */
  37 int i2c_probe(uint8_t chip);
  38
  39 /*
  40  * Read/Write interface:
  41  *   chip:    I2C chip address, range 0..127
  42  *   addr:    Memory (register) address within the chip
  43  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
  44  *              memories, 0 for register type devices with only one
  45  *              register)
  46  *   buffer:  Where to read/write the data
  47  *   len:     How many bytes to read/write
  48  *
  49  *   Returns: 0 on success, not 0 on failure
  50  */
  51 int i2c_read(uint8_t chip, unsigned int addr, uint_fast8_t alen,
  52                                 uint8_t *buffer, uint_fast8_t len);
  53 int i2c_write(uint8_t chip, unsigned int addr, uint_fast8_t alen,
  54                                 uint8_t *buffer, uint_fast8_t len);
  55
  56 /*
  57  * Utility routines to read/write registers.
  58  */
  59 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
  60
  61 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
  62
  63 #endif /* _I2C_H_*/