i2c: Implement i2c_get_chip_by_phandle()
This new function enhances the i2c_get_chip*() toolbox by implementing a
variant that does not require a chip_addr. Instead, the desired device
is pointed to by a phandle.
Signed-off-by: Philip Richard Oberfichtner <pro@denx.de>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
index 8867a56..5405067 100644
--- a/drivers/i2c/i2c-uclass.c
+++ b/drivers/i2c/i2c-uclass.c
@@ -388,6 +388,81 @@
return 0;
}
+/* Find and probe I2C bus based on a chip attached to it */
+static int i2c_get_parent_bus(ofnode chip, struct udevice **devp)
+{
+ ofnode node;
+ struct udevice *dev;
+ int ret;
+
+ node = ofnode_get_parent(chip);
+ if (!ofnode_valid(node))
+ return -ENODEV;
+
+ ret = uclass_get_device_by_ofnode(UCLASS_I2C, node, &dev);
+ if (ret) {
+ *devp = NULL;
+ return ret;
+ }
+
+ *devp = dev;
+ return 0;
+}
+
+int i2c_get_chip_by_phandle(const struct udevice *parent, const char *prop_name,
+ struct udevice **devp)
+{
+ ofnode node;
+ uint phandle;
+ struct udevice *bus, *chip;
+ char *dev_name;
+ int ret;
+
+ debug("%s: Searching I2C chip for phandle \"%s\"\n",
+ __func__, prop_name);
+
+ dev_name = strdup(prop_name);
+ if (!dev_name) {
+ ret = -ENOMEM;
+ goto err_exit;
+ }
+
+ ret = dev_read_u32(parent, "i2cbcdev", &phandle);
+ if (ret)
+ goto err_exit;
+
+ node = ofnode_get_by_phandle(phandle);
+ if (!ofnode_valid(node)) {
+ ret = -ENODEV;
+ goto err_exit;
+ }
+
+ ret = i2c_get_parent_bus(node, &bus);
+ if (ret)
+ goto err_exit;
+
+ ret = device_bind_driver_to_node(bus, "i2c_generic_chip_drv",
+ dev_name, node, &chip);
+ if (ret)
+ goto err_exit;
+
+ ret = device_probe(chip);
+ if (ret) {
+ device_unbind(chip);
+ goto err_exit;
+ }
+
+ debug("%s succeeded\n", __func__);
+ *devp = chip;
+ return 0;
+
+err_exit:
+ free(dev_name);
+ debug("%s failed, ret = %d\n", __func__, ret);
+ *devp = NULL;
+ return ret;
+}
+
int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
struct udevice **devp)
{
diff --git a/include/i2c.h b/include/i2c.h
index ef3820e..4e59009 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -538,6 +538,18 @@
struct udevice **devp);
/**
+ * i2c_get_chip_by_phandle() - get a device to use to access a chip
+ * based on a phandle property pointing to it
+ *
+ * @parent: Parent device containing the phandle pointer
+ * @name: Name of phandle property in the parent device node
+ * @devp: Returns pointer to new device or NULL if not found
+ * Return: 0 on success, -ve on failure
+ */
+int i2c_get_chip_by_phandle(const struct udevice *parent, const char *prop_name,
+ struct udevice **devp);
+
+/**
* i2c_chip_of_to_plat() - Decode standard I2C platform data
*
* This decodes the chip address from a device tree node and puts it into