dm: i2c: Add functions to read and write a register

Add driver model versions of the legacy functions to read and write a
single byte register. These are a useful shortcut in many cases.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Heiko Schocher <hs@denx.de>

1 files changed, 21 insertions, 0 deletions

diff --git a/include/i2c.h b/include/i2c.h
index 6fd73fae4cc..d794057f4b9 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -124,6 +124,27 @@ int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
 		 struct udevice **devp);
 
 /**
+ * dm_i2c_reg_read() - Read a value from an I2C register
+ *
+ * This reads a single value from the given address in an I2C chip
+ *
+ * @addr:	Address to read from
+ * @return value read, or -ve on error
+ */
+int dm_i2c_reg_read(struct udevice *dev, uint offset);
+
+/**
+ * dm_i2c_reg_write() - Write a value to an I2C register
+ *
+ * This writes a single value to the given address in an I2C chip
+ *
+ * @addr:	Address to write to
+ * @val:	Value to write (normally a byte)
+ * @return 0 on success, -ve on error
+ */
+int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
+
+/**
  * dm_i2c_set_bus_speed() - set the speed of a bus
  *
  * @bus:	Bus to adjust