spi: Propagate default fwnode to the SPI controller device

Most of the SPI controller drivers share the parent's fwnode
by explicit assignment. Propagate the default by SPI core,
so they may drop that in the code. Only corner cases may require
a special treatment and we simply (re)assign the controller's
fwnode explicitly (as it's done right now, no changes required
for that).

Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Tested-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260112203534.4186261-2-andriy.shevchenko@linux.intel.com
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: andy-shev

drivers/spi/spi-cs42l43.c

@@ -371,6 +371,14 @@ static int cs42l43_spi_probe(struct platform_device *pdev)
 
 	fwnode_property_read_u32(xu_fwnode, "01fa-sidecar-instances", &nsidecars);
 
+	/*
+	 * Depending on the value of nsidecars we either create a software node
+	 * or assign an fwnode. We don't want software node to be attached to
+	 * the default one. That's why we need to clear the SPI controller fwnode
+	 * first.
+	 */
+	device_set_node(&priv->ctlr->dev, NULL);
+
 	if (nsidecars) {
 		struct software_node_ref_args args[] = {
 			SOFTWARE_NODE_REFERENCE(fwnode, 0, GPIO_ACTIVE_LOW),

drivers/spi/spi.c

@@ -3072,6 +3072,9 @@ struct spi_controller *__spi_alloc_controller(struct device *dev,
 	else
 		ctlr->dev.class = &spi_controller_class;
 	ctlr->dev.parent = dev;
+
+	device_set_node(&ctlr->dev, dev_fwnode(dev));
+
 	pm_suspend_ignore_children(&ctlr->dev, true);
 	spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);