Add support for multiple I2C buses

Hello,

Attached is a patch providing support for multiple I2C buses at the
command level.  The second part of the patch includes an implementation
for the MPC834x CPU and MPC8349EMDS board.

/*** Note: This patch replaces ticket DNX#2006083042000018 ***/

Signed-off-by: Ben Warren <bwarren@qstreams.com>

Overview:

1. Include new 'i2c' command (based on USB implementation) using
CONFIG_I2C_CMD_TREE.

2. Allow multiple buses by defining CONFIG_I2C_MULTI_BUS.  Note that
the commands to change bus number and speed are only available under the
new 'i2c' command mentioned in the first bullet.

3. The option CFG_I2C_NOPROBES has been expanded to work in multi-bus
systems.  When CONFIG_I2C_MULTI_BUS is used, this option takes the form
of an array of bus-device pairs.  Otherwise, it is an array of uchar.

CHANGELOG:
        Added new 'i2c' master command for all I2C interaction.  This is
conditionally compiled with CONFIG_I2C_CMD_TREE.  New commands added for
setting I2C bus speed as well as changing the active bus if the board
has more than one (conditionally compiled with
CONFIG_I2C_MULTI_BUS).  Updated NOPROBE logic to handle multiple buses.
Updated README.

regards,
Ben

1 files changed, 45 insertions, 0 deletions

diff --git a/include/i2c.h b/include/i2c.h
index 6d39080d8f..97e006163a 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -82,4 +82,49 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
 uchar i2c_reg_read (uchar chip, uchar reg);
 void  i2c_reg_write(uchar chip, uchar reg, uchar val);
 
+/*
+ * Functions for setting the current I2C bus and its speed
+ */
+
+/*
+ * i2c_set_bus_num:
+ *
+ *  Change the active I2C bus.  Subsequent read/write calls will
+ *  go to this one.
+ *
+ * 	bus - bus index, zero based
+ *
+ * 	Returns: 0 on success, not 0 on failure
+ *
+ */
+int		i2c_set_bus_num(uchar bus);
+
+/*
+ * i2c_get_bus_num:
+ *
+ *  Returns index of currently active I2C bus.  Zero-based.
+ */
+
+uchar	i2c_get_bus_num(void);
+
+/*
+ * i2c_set_bus_speed:
+ *
+ *  Change the speed of the active I2C bus
+ *
+ * 	speed - bus speed in Hz
+ *
+ * 	Returns: 0 on success, not 0 on failure
+ *
+ */
+int		i2c_set_bus_speed(int);
+
+/*
+ * i2c_get_bus_speed:
+ *
+ *  Returns speed of currently active I2C bus in Hz
+ */
+
+int		i2c_get_bus_speed(void);
+
 #endif	/* _I2C_H_ */