linux-kernel - [PATCH] spi: cs42l43: Use actual ACPI firmware node for chip selects

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Message-ID: <20251119164017.1115791-1-ckeepax@opensource.cirrus.com>
Date: Wed, 19 Nov 2025 16:40:17 +0000
From: Charles Keepax <ckeepax@...nsource.cirrus.com>
To: broonie@...nel.org, brgl@...ev.pl, linus.walleij@...aro.org
Cc: andy@...nel.org, p.zabel@...gutronix.de, linux-gpio@...r.kernel.org,
        linux-spi@...r.kernel.org, bartosz.golaszewski@...aro.org,
        linux-kernel@...r.kernel.org, patches@...nsource.cirrus.com
Subject: [PATCH] spi: cs42l43: Use actual ACPI firmware node for chip selects

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 bit of a hack. A software
node is added with the same name as the pinctrl driver, as the look
up was name based this caused the GPIO looks to return the pinctrl
driver even though the swnode is not associated with the pinctrl
driver. 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. But other patches also add support
for linking a swnode to a real fwnode node [1]. As such switch over to
just passing the real fwnode for the pinctrl property to avoid any
issues.

[1] https://lore.kernel.org/linux-gpio/20251106-reset-gpios-swnodes-v6-0-69aa852de9e4@linaro.org/

Signed-off-by: Charles Keepax <ckeepax@...nsource.cirrus.com>
---

Ok here is what I would propose to fix this one, IMPORTANT NOTE: this
does depend on the first four patches of the linked chain which I don't
think are merged yet. But I would argue if we are removing the name
based look up, we should add support for fwnodes at the same time.

 drivers/spi/spi-cs42l43.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/drivers/spi/spi-cs42l43.c b/drivers/spi/spi-cs42l43.c
index 14307dd800b74..b7dd5f6ecc30e 100644
--- a/drivers/spi/spi-cs42l43.c
+++ b/drivers/spi/spi-cs42l43.c
@@ -52,12 +52,8 @@ 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(NULL, 0, GPIO_ACTIVE_LOW),
 	SOFTWARE_NODE_REFERENCE(&swnode_gpio_undefined),
 };
 
@@ -324,11 +320,6 @@ 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 +382,9 @@ 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;
+		struct property_entry *props;
+
 		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 +397,20 @@ 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");
+		props = devm_kmemdup(priv->dev, cs42l43_cs_props, sizeof(cs42l43_cs_props),
+				     GFP_KERNEL);
+		if (!props)
+			return -ENOMEM;
 
-		ret = devm_add_action_or_reset(priv->dev, cs42l43_release_sw_node, NULL);
-		if (ret)
-			return ret;
+		args = devm_kmemdup(priv->dev, cs42l43_cs_refs, sizeof(cs42l43_cs_refs),
+				    GFP_KERNEL);
+		if (!args)
+			return -ENOMEM;
+
+		args[0].fwnode = fwnode;
+		props->pointer = args;
 
-		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