[PATCH v4 2/3] usb: typec: cros_ec_ucsi: Load driver from OF and ACPI definitions

[Jameson Thies <jthies@google.com>]

Add support for cros_ec_ucsi to load based on "google,cros-ec-ucsi"
compatible devices and "GOOG0021" ACPI nodes.

Signed-off-by: Jameson Thies <jthies@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
---
 drivers/usb/typec/ucsi/cros_ec_ucsi.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/ucsi/cros_ec_ucsi.c b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
index eed2a7d0ebc6..0c19ba84d11c 100644
--- a/drivers/usb/typec/ucsi/cros_ec_ucsi.c
+++ b/drivers/usb/typec/ucsi/cros_ec_ucsi.c
@@ -5,11 +5,13 @@
  * Copyright 2024 Google LLC.
  */
 
+#include <linux/acpi.h>
 #include <linux/container_of.h>
 #include <linux/dev_printk.h>
 #include <linux/jiffies.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_usbpd_notify.h>
 #include <linux/platform_data/cros_ec_proto.h>
@@ -235,7 +237,6 @@ static void cros_ucsi_destroy(struct cros_ucsi_data *udata)
 static int cros_ucsi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct cros_ec_dev *ec_data = dev_get_drvdata(dev->parent);
 	struct cros_ucsi_data *udata;
 	int ret;
 
@@ -243,9 +244,16 @@ static int cros_ucsi_probe(struct platform_device *pdev)
 	if (!udata)
 		return -ENOMEM;
 
+	/* ACPI and OF FW nodes for cros_ec_ucsi are children of the ChromeOS EC. If the
+	 * cros_ec_ucsi device has an ACPI or OF FW node, its parent is the ChromeOS EC device.
+	 * Platforms without a FW node for cros_ec_ucsi may add it as a subdevice of cros_ec_dev.
+	 */
 	udata->dev = dev;
+	if (is_acpi_device_node(dev->fwnode) || is_of_node(dev->fwnode))
+		udata->ec = dev_get_drvdata(dev->parent);
+	else
+		udata->ec = ((struct cros_ec_dev *)dev_get_drvdata(dev->parent))->ec_dev;
 
-	udata->ec = ec_data->ec_dev;
 	if (!udata->ec)
 		return dev_err_probe(dev, -ENODEV, "couldn't find parent EC device\n");
 
@@ -326,10 +334,24 @@ static const struct platform_device_id cros_ucsi_id[] = {
 };
 MODULE_DEVICE_TABLE(platform, cros_ucsi_id);
 
+static const struct acpi_device_id cros_ec_ucsi_acpi_device_ids[] = {
+	{ "GOOG0021", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, cros_ec_ucsi_acpi_device_ids);
+
+static const struct of_device_id cros_ucsi_of_match[] = {
+	{ .compatible = "google,cros-ec-ucsi", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, cros_ucsi_of_match);
+
 static struct platform_driver cros_ucsi_driver = {
 	.driver = {
 		.name = KBUILD_MODNAME,
 		.pm = &cros_ucsi_pm_ops,
+		.acpi_match_table = cros_ec_ucsi_acpi_device_ids,
+		.of_match_table = cros_ucsi_of_match,
 	},
 	.id_table = cros_ucsi_id,
 	.probe = cros_ucsi_probe,
-- 
2.51.0.858.gf9c4a03a3a-goog