platform/chrome: cros_usbpd_notify: Amend ACPI driver to plat

Convert the ACPI driver into the equivalent platform driver, with the
same ACPI match table as before. This allows the device driver to access
the parent platform EC device and its cros_ec_device struct, which will
be required to communicate with the EC to pull PD Host event information
from it.

Also change the ACPI driver name to "cros-usbpd-notify-acpi" so that
there is no confusion between it and the "regular" platform driver on
platforms that have both CONFIG_ACPI and CONFIG_OF enabled.
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

drivers/platform/chrome/cros_usbpd_notify.c

@@ -12,6 +12,7 @@
 #include <linux/platform_device.h>
 
 #define DRV_NAME "cros-usbpd-notify"
+#define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"
 #define ACPI_DRV_NAME "GOOG0003"
 
 static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);
@@ -54,14 +55,61 @@ EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);
 
 #ifdef CONFIG_ACPI
 
-static int cros_usbpd_notify_add_acpi(struct acpi_device *adev)
+static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data)
 {
+	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+}
+
+static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
+{
+	struct cros_usbpd_notify_data *pdnotify;
+	struct device *dev = &pdev->dev;
+	struct acpi_device *adev;
+	struct cros_ec_device *ec_dev;
+	acpi_status status;
+
+	adev = ACPI_COMPANION(dev);
+
+	pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
+	if (!pdnotify)
+		return -ENOMEM;
+
+	/* Get the EC device pointer needed to talk to the EC. */
+	ec_dev = dev_get_drvdata(dev->parent);
+	if (!ec_dev) {
+		/*
+		 * We continue even for older devices which don't have the
+		 * correct device heirarchy, namely, GOOG0003 is a child
+		 * of GOOG0004.
+		 */
+		dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");
+	}
+
+	pdnotify->dev = dev;
+	pdnotify->ec = ec_dev;
+
+	status = acpi_install_notify_handler(adev->handle,
+					     ACPI_ALL_NOTIFY,
+					     cros_usbpd_notify_acpi,
+					     pdnotify);
+	if (ACPI_FAILURE(status)) {
+		dev_warn(dev, "Failed to register notify handler %08x\n",
+			 status);
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
-static void cros_usbpd_notify_acpi(struct acpi_device *adev, u32 event)
+static int cros_usbpd_notify_remove_acpi(struct platform_device *pdev)
 {
-	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
+	struct device *dev = &pdev->dev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+
+	acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
+				   cros_usbpd_notify_acpi);
+
+	return 0;
 }
 
 static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
@@ -70,14 +118,13 @@ static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
 };
 MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);
 
-static struct acpi_driver cros_usbpd_notify_acpi_driver = {
-	.name = DRV_NAME,
-	.class = DRV_NAME,
-	.ids = cros_usbpd_notify_acpi_device_ids,
-	.ops = {
-		.add = cros_usbpd_notify_add_acpi,
-		.notify = cros_usbpd_notify_acpi,
+static struct platform_driver cros_usbpd_notify_acpi_driver = {
+	.driver = {
+		.name = DRV_NAME_PLAT_ACPI,
+		.acpi_match_table = cros_usbpd_notify_acpi_device_ids,
 	},
+	.probe = cros_usbpd_notify_probe_acpi,
+	.remove = cros_usbpd_notify_remove_acpi,
 };
 
 #endif /* CONFIG_ACPI */
@@ -157,7 +204,7 @@ static int __init cros_usbpd_notify_init(void)
 		return ret;
 
 #ifdef CONFIG_ACPI
-	acpi_bus_register_driver(&cros_usbpd_notify_acpi_driver);
+	platform_driver_register(&cros_usbpd_notify_acpi_driver);
 #endif
 	return 0;
 }
@@ -165,7 +212,7 @@ static int __init cros_usbpd_notify_init(void)
 static void __exit cros_usbpd_notify_exit(void)
 {
 #ifdef CONFIG_ACPI
-	acpi_bus_unregister_driver(&cros_usbpd_notify_acpi_driver);
+	platform_driver_unregister(&cros_usbpd_notify_acpi_driver);
 #endif
 	platform_driver_unregister(&cros_usbpd_notify_plat_driver);
 }