[U-Boot] [PATCH v1 02/19] dm: i2c: Add dm_i2c_probe_device() to test the presence of a chip

[Jean-Jacques Hiblot]

In a non-DM environment, it is possible to test the presence of a chip
using i2c_probe(chip_addr).
dm_i2c_probe_device() brings the same functionality with a DM interface.
The intent is to be able to test the presence of a chip for the device has
been created with i2c_get_chip_for_busnum(bus_num, chip_addr, ...)

Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
---

 drivers/i2c/i2c-uclass.c |  8 ++++++++
 include/i2c.h            | 13 +++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
index c5a3c4e..ec88168 100644
--- a/drivers/i2c/i2c-uclass.c
+++ b/drivers/i2c/i2c-uclass.c
@@ -378,6 +378,14 @@ int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
 	return ret;
 }
 
+int dm_i2c_probe_device(struct udevice *dev)
+{
+	struct udevice *bus = dev_get_parent(dev);
+	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
+
+	return i2c_probe_chip(bus, chip->chip_addr, chip->flags);
+}
+
 int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 {
 	struct dm_i2c_ops *ops = i2c_get_ops(bus);
diff --git a/include/i2c.h b/include/i2c.h
index d33f827..3c8fde2 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -167,6 +167,19 @@ int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
 		 struct udevice **devp);
 
 /**
+ * dm_i2c_probe_dev() - probe the presence of a I2C device
+ *
+ * This can be useful to check for the existence of a chip already probed
+ * (software wise).
+ * It is typically implemented by writing the chip address to the bus
+ * and checking that the chip replies with an ACK.
+ *
+ * @bus:	Device to probe
+ * @return 0 if a chip was found at that address, -ve if not
+ */
+int dm_i2c_probe_device(struct udevice *dev);
+
+/**
  * dm_i2c_reg_read() - Read a value from an I2C register
  *
  * This reads a single value from the given address in an I2C chip
-- 
2.7.4