[PATCH v2] spi: cs42l43: Use actual ACPI firmware node for chip selects

[Charles Keepax <ckeepax@opensource.cirrus.com>]

On some systems the cs42l43 has amplifiers attached to its SPI
controller that are not properly defined in ACPI. Currently
software nodes are added to support this case, however, the chip
selects for these devices are specified using a hack. A software
node is added with the same name as the pinctrl driver, as the
look up was name based, this allowed the GPIO look up to return
the pinctrl driver even though the swnode was not owned by it.
This was necessary as the swnodes did not support directly
linking to real firmware nodes.

Since commit e5d527be7e69 ("gpio: swnode: don't use the swnode's
name as the key for GPIO lookup") changed the lookup to be
fwnode based this hack will no longer find the pinctrl driver,
resulting in the driver not probing. There is no pinctrl driver
attached to the swnode itself. But other patches did add support
for linking a swnode to a real fwnode node [1]. As such the hack
is no longer needed, so switch over to just passing the real
fwnode for the pinctrl property to avoid any issues.

Link: https://lore.kernel.org/linux-gpio/20251106-reset-gpios-swnodes-v6-0-69aa852de9e4@linaro.org/ [1]
Fixes: 439fbc97502a ("spi: cs42l43: Add bridged cs35l56 amplifiers")
Fixes: e5d527be7e69 ("gpio: swnode: don't use the swnode's name as the key for GPIO lookup")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

IMPORTANT NOTE: This depends both functionally and build wise on the
linked series from Bart, it probably makes sense for him to pull the
patch into his series.

Changes since v1:
 - Add missing tags
 - Move swnode config onto the stack, since the core copies it

 drivers/spi/spi-cs42l43.c | 40 ++++++++++-----------------------------
 1 file changed, 10 insertions(+), 30 deletions(-)

diff --git a/drivers/spi/spi-cs42l43.c b/drivers/spi/spi-cs42l43.c
index 14307dd800b74..43079f292d6f7 100644
--- a/drivers/spi/spi-cs42l43.c
+++ b/drivers/spi/spi-cs42l43.c
@@ -52,20 +52,6 @@ static struct spi_board_info amp_info_template = {
 	.mode			= SPI_MODE_0,
 };
 
-static const struct software_node cs42l43_gpiochip_swnode = {
-	.name			= "cs42l43-pinctrl",
-};
-
-static const struct software_node_ref_args cs42l43_cs_refs[] = {
-	SOFTWARE_NODE_REFERENCE(&cs42l43_gpiochip_swnode, 0, GPIO_ACTIVE_LOW),
-	SOFTWARE_NODE_REFERENCE(&swnode_gpio_undefined),
-};
-
-static const struct property_entry cs42l43_cs_props[] = {
-	PROPERTY_ENTRY_REF_ARRAY("cs-gpios", cs42l43_cs_refs),
-	{}
-};
-
 static int cs42l43_spi_tx(struct regmap *regmap, const u8 *buf, unsigned int len)
 {
 	const u8 *end = buf + len;
@@ -324,11 +310,6 @@ static void cs42l43_release_of_node(void *data)
 	fwnode_handle_put(data);
 }
 
-static void cs42l43_release_sw_node(void *data)
-{
-	software_node_unregister(&cs42l43_gpiochip_swnode);
-}
-
 static int cs42l43_spi_probe(struct platform_device *pdev)
 {
 	struct cs42l43 *cs42l43 = dev_get_drvdata(pdev->dev.parent);
@@ -391,6 +372,15 @@ static int cs42l43_spi_probe(struct platform_device *pdev)
 	fwnode_property_read_u32(xu_fwnode, "01fa-sidecar-instances", &nsidecars);
 
 	if (nsidecars) {
+		struct software_node_ref_args args[] = {
+			SOFTWARE_NODE_REFERENCE(fwnode, 0, GPIO_ACTIVE_LOW),
+			SOFTWARE_NODE_REFERENCE(&swnode_gpio_undefined),
+		};
+		struct property_entry props[] = {
+			PROPERTY_ENTRY_REF_ARRAY_LEN("cs-gpios", args, ARRAY_SIZE(args)),
+			{ }
+		};
+
 		ret = fwnode_property_read_u32(xu_fwnode, "01fa-spk-id-val", &spkid);
 		if (!ret) {
 			dev_dbg(priv->dev, "01fa-spk-id-val = %d\n", spkid);
@@ -403,17 +393,7 @@ static int cs42l43_spi_probe(struct platform_device *pdev)
 						     "Failed to get spk-id-gpios\n");
 		}
 
-		ret = software_node_register(&cs42l43_gpiochip_swnode);
-		if (ret)
-			return dev_err_probe(priv->dev, ret,
-					     "Failed to register gpio swnode\n");
-
-		ret = devm_add_action_or_reset(priv->dev, cs42l43_release_sw_node, NULL);
-		if (ret)
-			return ret;
-
-		ret = device_create_managed_software_node(&priv->ctlr->dev,
-							  cs42l43_cs_props, NULL);
+		ret = device_create_managed_software_node(&priv->ctlr->dev, props, NULL);
 		if (ret)
 			return dev_err_probe(priv->dev, ret, "Failed to add swnode\n");
 	} else {
-- 
2.47.3