Initial revision

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_ */