[PATCH] ASoC: cs35l56: Workaround for ACPI with broken spk-id-gpios property

[Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>]

The ACPI in some SoundWire laptops has a spk-id-gpios property but
it points to the wrong Device node. This patch adds a workaround to
try to get the GPIO directly from the correct Device node.

If the attempt to get the GPIOs from the property fails, the workaround
looks for the SDCA node "AF01", which is where the GpioIo resource is
defined. If this exists, a spk-id-gpios mapping is added to that node
and then the GPIO is got from that node using the property.

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
---
 sound/soc/codecs/cs35l56.c | 93 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index 98d3957c66e7..2c1313e34cce 100644
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -5,6 +5,7 @@
 // Copyright (C) 2023 Cirrus Logic, Inc. and
 //                    Cirrus Logic International Semiconductor Ltd.
 
+#include <linux/acpi.h>
 #include <linux/completion.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
@@ -15,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
@@ -1260,6 +1262,94 @@ static int cs35l56_get_firmware_uid(struct cs35l56_private *cs35l56)
 	return 0;
 }
 
+/*
+ * Some SoundWire laptops have a spk-id-gpios property but it points to
+ * the wrong ACPI Device node so can't be used to get the GPIO. Try to
+ * find the SDCA node containing the GpioIo resource and add a GPIO
+ * mapping to it.
+ */
+static const struct acpi_gpio_params cs35l56_af01_first_gpio = { 0, 0, false };
+static const struct acpi_gpio_mapping cs35l56_af01_spkid_gpios_mapping[] = {
+	{ "spk-id-gpios", &cs35l56_af01_first_gpio, 1 },
+	{ }
+};
+
+static void cs35l56_acpi_dev_release_driver_gpios(void *adev)
+{
+	acpi_dev_remove_driver_gpios(adev);
+}
+
+static int cs35l56_try_get_broken_sdca_spkid_gpio(struct cs35l56_private *cs35l56)
+{
+	struct fwnode_handle *af01_fwnode;
+	const union acpi_object *obj;
+	struct gpio_desc *desc;
+	int ret;
+
+	/* Find the SDCA node containing the GpioIo */
+	af01_fwnode = device_get_named_child_node(cs35l56->base.dev, "AF01");
+	if (!af01_fwnode) {
+		dev_dbg(cs35l56->base.dev, "No AF01 node\n");
+		return -ENOENT;
+	}
+
+	ret = acpi_dev_get_property(ACPI_COMPANION(cs35l56->base.dev),
+				    "spk-id-gpios", ACPI_TYPE_PACKAGE, &obj);
+	if (ret) {
+		dev_dbg(cs35l56->base.dev, "Could not get spk-id-gpios package: %d\n", ret);
+		return -ENOENT;
+	}
+
+	/* The broken properties we can handle are a 4-element package (one GPIO) */
+	if (obj->package.count != 4) {
+		dev_warn(cs35l56->base.dev, "Unexpected spk-id element count %d\n",
+			 obj->package.count);
+		return -ENOENT;
+	}
+
+	/* Add a GPIO mapping if it doesn't already have one */
+	if (!fwnode_property_present(af01_fwnode, "spk-id-gpios")) {
+		struct acpi_device *adev = to_acpi_device_node(af01_fwnode);
+
+		/*
+		 * Can't use devm_acpi_dev_add_driver_gpios() because the
+		 * mapping isn't being added to the node pointed to by
+		 * ACPI_COMPANION().
+		 */
+		ret = acpi_dev_add_driver_gpios(adev, cs35l56_af01_spkid_gpios_mapping);
+		if (ret) {
+			return dev_err_probe(cs35l56->base.dev, ret,
+					     "Failed to add gpio mapping to AF01\n");
+		}
+
+		ret = devm_add_action_or_reset(cs35l56->base.dev,
+					       cs35l56_acpi_dev_release_driver_gpios,
+					       adev);
+		if (ret)
+			return ret;
+
+		dev_dbg(cs35l56->base.dev, "Added spk-id-gpios mapping to AF01\n");
+	}
+
+	desc = fwnode_gpiod_get_index(af01_fwnode, "spk-id", 0, GPIOD_IN, NULL);
+	if (IS_ERR(desc)) {
+		ret = PTR_ERR(desc);
+		return dev_err_probe(cs35l56->base.dev, ret, "Get GPIO from AF01 failed\n");
+	}
+
+	ret = gpiod_get_value_cansleep(desc);
+	gpiod_put(desc);
+
+	if (ret < 0) {
+		dev_err_probe(cs35l56->base.dev, ret, "Error reading spk-id GPIO\n");
+		return ret;
+		}
+
+	dev_info(cs35l56->base.dev, "Got spk-id from AF01\n");
+
+	return ret;
+}
+
 int cs35l56_common_probe(struct cs35l56_private *cs35l56)
 {
 	int ret;
@@ -1304,6 +1394,9 @@ int cs35l56_common_probe(struct cs35l56_private *cs35l56)
 	}
 
 	ret = cs35l56_get_speaker_id(&cs35l56->base);
+	if (ACPI_COMPANION(cs35l56->base.dev) && cs35l56->sdw_peripheral && (ret == -ENOENT))
+		ret = cs35l56_try_get_broken_sdca_spkid_gpio(cs35l56);
+
 	if ((ret < 0) && (ret != -ENOENT))
 		goto err;
 
-- 
2.30.2