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Diffstat (limited to 'include/i2c.h')
-rw-r--r-- | include/i2c.h | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/include/i2c.h b/include/i2c.h new file mode 100644 index 0000000..43d76fd --- /dev/null +++ b/include/i2c.h @@ -0,0 +1,82 @@ +/* + * (C) Copyright 2001 + * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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; either version 2 of + * the License, or (at your option) any later version. + * + * 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + * The original I2C interface was + * (C) 2000 by Paolo Scaffardi (arsenio@tin.it) + * AIRVENT SAM s.p.a - RIMINI(ITALY) + * but has been changed substantially. + */ + +#ifndef _I2C_H_ +#define _I2C_H_ + +/* + * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING + * + * The implementation MUST NOT use static or global variables if the + * I2C routines are used to read SDRAM configuration information + * because this is done before the memories are initialized. Limited + * use of stack-based variables are OK (the initial stack size is + * limited). + * + * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING + */ + +/* + * Configuration items. + */ +#define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */ + +/* + * Initialization, must be called once on start up, may be called + * repeatedly to change the speed and slave addresses. + */ +void i2c_init(int speed, int slaveaddr); + +/* + * Probe the given I2C chip address. Returns 0 if a chip responded, + * not 0 on failure. + */ +int i2c_probe(uchar chip); + +/* + * Read/Write interface: + * chip: I2C chip address, range 0..127 + * addr: Memory (register) address within the chip + * alen: Number of bytes to use for addr (typically 1, 2 for larger + * memories, 0 for register type devices with only one + * register) + * buffer: Where to read/write the data + * len: How many bytes to read/write + * + * Returns: 0 on success, not 0 on failure + */ +int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len); +int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); + +/* + * Utility routines to read/write registers. + */ +uchar i2c_reg_read (uchar chip, uchar reg); +void i2c_reg_write(uchar chip, uchar reg, uchar val); + +#endif /* _I2C_H_ */ |