1 files changed, 69 insertions, 14 deletions

diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index c5f0d936b003..fe97d6085f6d 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -32,7 +32,18 @@ static ssize_t modalias_show(struct device *dev,
         if (len != -ENODEV)
                 return len;
 
-        return of_device_modalias(dev, buf, PAGE_SIZE);
+        len = of_device_modalias(dev, buf, PAGE_SIZE);
+        if (len != -ENODEV)
+                return len;
+
+        if (dev->parent->parent->bus == &platform_bus_type) {
+                struct platform_device *pdev =
+                        to_platform_device(dev->parent->parent);
+
+                len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
+        }
+
+        return len;
 }
 static DEVICE_ATTR_RO(modalias);
 
@@ -46,13 +57,18 @@ static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
         int rc;
 
-        /* TODO: platform modalias */
-
         rc = acpi_device_uevent_modalias(dev, env);
         if (rc != -ENODEV)
                 return rc;
 
-        return of_device_uevent_modalias(dev, env);
+        rc = of_device_uevent_modalias(dev, env);
+        if (rc != -ENODEV)
+                return rc;
+
+        if (dev->parent->parent->bus == &platform_bus_type)
+                rc = dev->parent->parent->bus->uevent(dev->parent->parent, env);
+
+        return rc;
 }
 
 static void serdev_device_release(struct device *dev)
@@ -88,11 +104,17 @@ static int serdev_device_match(struct device *dev, struct device_driver *drv)
         if (!is_serdev_device(dev))
                 return 0;
 
-        /* TODO: platform matching */
         if (acpi_driver_match_device(dev, drv))
                 return 1;
 
-        return of_driver_match_device(dev, drv);
+        if (of_driver_match_device(dev, drv))
+                return 1;
+
+        if (dev->parent->parent->bus == &platform_bus_type &&
+            dev->parent->parent->bus->match(dev->parent->parent, drv))
+                return 1;
+
+        return 0;
 }
 
 /**
@@ -729,16 +751,45 @@ static inline int acpi_serdev_register_devices(struct serdev_controller *ctrl)
 }
 #endif /* CONFIG_ACPI */
 
+static int platform_serdev_register_devices(struct serdev_controller *ctrl)
+{
+        struct serdev_device *serdev;
+        int err;
+
+        if (ctrl->dev.parent->bus != &platform_bus_type)
+                return -ENODEV;
+
+        serdev = serdev_device_alloc(ctrl);
+        if (!serdev) {
+                dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
+                                    dev_name(ctrl->dev.parent));
+                return -ENOMEM;
+        }
+
+        pm_runtime_no_callbacks(&serdev->dev);
+
+        err = serdev_device_add(serdev);
+        if (err) {
+                dev_err(&serdev->dev,
+                        "failure adding device. status %d\n", err);
+                serdev_device_put(serdev);
+        }
+
+        return err;
+}
+
+
 /**
- * serdev_controller_add() - Add an serdev controller
+ * serdev_controller_add_platform() - Add an serdev controller
  * @ctrl:       controller to be registered.
+ * @platform:   whether to permit fallthrough to platform device probe
  *
  * Register a controller previously allocated via serdev_controller_alloc() with
- * the serdev core.
+ * the serdev core. Optionally permit probing via a platform device fallback.
  */
-int serdev_controller_add(struct serdev_controller *ctrl)
+int serdev_controller_add_platform(struct serdev_controller *ctrl, bool platform)
 {
-        int ret_of, ret_acpi, ret;
+        int ret, ret_of, ret_acpi, ret_platform = -ENODEV;
 
         /* Can't register until after driver model init */
         if (WARN_ON(!is_registered))
@@ -752,9 +803,13 @@ int serdev_controller_add(struct serdev_controller *ctrl)
 
         ret_of = of_serdev_register_devices(ctrl);
         ret_acpi = acpi_serdev_register_devices(ctrl);
-        if (ret_of && ret_acpi) {
-                dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
-                        ERR_PTR(ret_of), ERR_PTR(ret_acpi));
+        if (platform)
+                ret_platform = platform_serdev_register_devices(ctrl);
+        if (ret_of && ret_acpi && ret_platform) {
+                dev_dbg(&ctrl->dev,
+                        "no devices registered: of:%pe acpi:%pe platform:%pe\n",
+                        ERR_PTR(ret_of), ERR_PTR(ret_acpi),
+                        ERR_PTR(ret_platform));
                 ret = -ENODEV;
                 goto err_rpm_disable;
         }
@@ -768,7 +823,7 @@ err_rpm_disable:
         device_del(&ctrl->dev);
         return ret;
 };
-EXPORT_SYMBOL_GPL(serdev_controller_add);
+EXPORT_SYMBOL_GPL(serdev_controller_add_platform);
 
 /* Remove a device associated with a controller */
 static int serdev_remove_device(struct device *dev, void *data)