dm: i2c: Move slave details to child platdata

At present we go through various contortions to store the I2C's chip
address in its private data. This only exists when the chip is active so
must be set up when it is probed. Until the device is probed we don't
actually record what address it will appear on.

However, now that we can support per-child platform data, we can use that
instead. This allows us to set up the address when the child is bound,
and avoid the messy contortions.

Unfortunately this is a fairly large change and it seems to be difficult to
break it down further.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/drivers/i2c/sandbox_i2c.c b/drivers/i2c/sandbox_i2c.c
index e2f6c3b..a943aa6 100644
--- a/drivers/i2c/sandbox_i2c.c
+++ b/drivers/i2c/sandbox_i2c.c
@@ -25,24 +25,24 @@
 static int get_emul(struct udevice *dev, struct udevice **devp,
 		    struct dm_i2c_ops **opsp)
 {
-	struct dm_i2c_chip *priv;
+	struct dm_i2c_chip *plat;
 	int ret;
 
 	*devp = NULL;
 	*opsp = NULL;
-	priv = dev_get_parentdata(dev);
-	if (!priv->emul) {
+	plat = dev_get_parent_platdata(dev);
+	if (!plat->emul) {
 		ret = dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset,
 				       false);
 		if (ret)
 			return ret;
 
-		ret = device_get_child(dev, 0, &priv->emul);
+		ret = device_get_child(dev, 0, &plat->emul);
 		if (ret)
 			return ret;
 	}
-	*devp = priv->emul;
-	*opsp = i2c_get_ops(priv->emul);
+	*devp = plat->emul;
+	*opsp = i2c_get_ops(plat->emul);
 
 	return 0;
 }
@@ -82,20 +82,6 @@
 	.xfer		= sandbox_i2c_xfer,
 };
 
-static int sandbox_i2c_child_pre_probe(struct udevice *dev)
-{
-	struct dm_i2c_chip *i2c_chip = dev_get_parentdata(dev);
-
-	/* Ignore our test address */
-	if (i2c_chip->chip_addr == SANDBOX_I2C_TEST_ADDR)
-		return 0;
-	if (dev->of_offset == -1)
-		return 0;
-
-	return i2c_chip_ofdata_to_platdata(gd->fdt_blob, dev->of_offset,
-					   i2c_chip);
-}
-
 static const struct udevice_id sandbox_i2c_ids[] = {
 	{ .compatible = "sandbox,i2c" },
 	{ }
@@ -105,7 +91,5 @@
 	.name	= "i2c_sandbox",
 	.id	= UCLASS_I2C,
 	.of_match = sandbox_i2c_ids,
-	.per_child_auto_alloc_size = sizeof(struct dm_i2c_chip),
-	.child_pre_probe = sandbox_i2c_child_pre_probe,
 	.ops	= &sandbox_i2c_ops,
 };