kernel-device: Add get_wwandev_sysfs_path

The wwan subsystem is a new bus agnostic framework exposing wwan
device and its components (ports, netdev...). It can be useful to
get the wwan device a device belongs to

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>

src/kerneldevice/mm-kernel-device-generic.c

@@ -58,6 +58,7 @@ struct _MMKernelDeviceGenericPrivate {
     gchar  **drivers;
     gchar  **subsystems;
     gchar   *sysfs_path;
+    gchar   *wwandev_sysfs_path;
     gchar   *interface_sysfs_path;
     guint8   interface_class;
     guint8   interface_subclass;
@@ -460,6 +461,30 @@ preload_contents_usb (MMKernelDeviceGeneric *self)
     self->priv->subsystems = (gchar **) g_ptr_array_free (subsystems, FALSE);
 }
 
+static void
+preload_contents_wwan (MMKernelDeviceGeneric *self)
+{
+    g_autofree gchar *iter = NULL;
+
+    /* Find the first parent device subsystem */
+    iter = g_path_get_dirname(self->priv->sysfs_path);
+    while (iter && (g_strcmp0 (iter, "/") != 0)) {
+        g_autofree gchar *current_subsystem = NULL;
+        gchar            *parent;
+
+        current_subsystem = read_sysfs_attribute_link_basename (iter, "subsystem");
+        if (current_subsystem) {
+            if (g_strcmp0 (current_subsystem, "wwan") == 0)
+                self->priv->wwandev_sysfs_path = g_strdup (iter);
+            break;
+        }
+
+        parent = g_path_get_dirname (iter);
+        g_clear_pointer (&iter, g_free);
+        iter = parent;
+    }
+}
+
 static gchar *
 find_device_bus_subsystem (MMKernelDeviceGeneric *self)
 {
@@ -518,6 +543,8 @@ preload_contents (MMKernelDeviceGeneric *self)
     else
         preload_contents_other (self);
 
+    preload_contents_wwan (self); /* wwan is bus agnostic class */
+
     if (!bus_subsys)
         return;
 
@@ -580,6 +607,12 @@ kernel_device_get_sysfs_path (MMKernelDevice *self)
     return MM_KERNEL_DEVICE_GENERIC (self)->priv->sysfs_path;
 }
 
+static const gchar *
+kernel_device_get_wwandev_sysfs_path (MMKernelDevice *self)
+{
+    return MM_KERNEL_DEVICE_GENERIC (self)->priv->wwandev_sysfs_path;
+}
+
 static gint
 kernel_device_get_interface_number (MMKernelDevice *self)
 {
@@ -1200,6 +1233,7 @@ mm_kernel_device_generic_class_init (MMKernelDeviceGenericClass *klass)
     kernel_device_class->get_name                  = kernel_device_get_name;
     kernel_device_class->get_driver                = kernel_device_get_driver;
     kernel_device_class->get_sysfs_path            = kernel_device_get_sysfs_path;
+    kernel_device_class->get_wwandev_sysfs_path    = kernel_device_get_wwandev_sysfs_path;
     kernel_device_class->get_physdev_uid           = kernel_device_get_physdev_uid;
     kernel_device_class->get_physdev_vid           = kernel_device_get_physdev_vid;
     kernel_device_class->get_physdev_pid           = kernel_device_get_physdev_pid;

src/kerneldevice/mm-kernel-device-udev.c

@@ -347,6 +347,27 @@ kernel_device_get_sysfs_path (MMKernelDevice *_self)
             NULL);
 }
 
+static const gchar *
+kernel_device_get_wwandev_sysfs_path (MMKernelDevice *_self)
+{
+    g_autoptr(GUdevDevice) parent = NULL;
+    MMKernelDeviceUdev *self;
+    const gchar *subsys;
+
+    self = MM_KERNEL_DEVICE_UDEV (_self);
+    parent = g_udev_device_get_parent (self->priv->device);
+
+    if (!parent)
+        return NULL;
+
+    subsys = g_udev_device_get_subsystem (parent);
+
+    if (!subsys || g_strcmp0 (subsys, "wwan"))
+        return NULL;
+
+    return g_udev_device_get_sysfs_path (parent);
+}
+
 static const gchar *
 kernel_device_get_physdev_uid (MMKernelDevice *_self)
 {
@@ -780,6 +801,7 @@ mm_kernel_device_udev_class_init (MMKernelDeviceUdevClass *klass)
     kernel_device_class->get_name                  = kernel_device_get_name;
     kernel_device_class->get_driver                = kernel_device_get_driver;
     kernel_device_class->get_sysfs_path            = kernel_device_get_sysfs_path;
+    kernel_device_class->get_wwandev_sysfs_path    = kernel_device_get_wwandev_sysfs_path;
     kernel_device_class->get_physdev_uid           = kernel_device_get_physdev_uid;
     kernel_device_class->get_physdev_vid           = kernel_device_get_physdev_vid;
     kernel_device_class->get_physdev_pid           = kernel_device_get_physdev_pid;

src/kerneldevice/mm-kernel-device.c

@@ -73,6 +73,14 @@ mm_kernel_device_get_sysfs_path (MMKernelDevice *self)
             NULL);
 }
 
+const gchar *
+mm_kernel_device_get_wwandev_sysfs_path (MMKernelDevice *self)
+{
+    return (MM_KERNEL_DEVICE_GET_CLASS (self)->get_wwandev_sysfs_path ?
+            MM_KERNEL_DEVICE_GET_CLASS (self)->get_wwandev_sysfs_path (self) :
+            NULL);
+}
+
 const gchar *
 mm_kernel_device_get_physdev_uid (MMKernelDevice *self)
 {

src/kerneldevice/mm-kernel-device.h

@@ -43,6 +43,8 @@ struct _MMKernelDeviceClass {
     const gchar * (* get_driver)      (MMKernelDevice *self);
     const gchar * (* get_sysfs_path)  (MMKernelDevice *self);
 
+    const gchar * (* get_wwandev_sysfs_path) (MMKernelDevice *self);
+
     gint          (* get_interface_number)      (MMKernelDevice *self);
     gint          (* get_interface_class)       (MMKernelDevice *self);
     gint          (* get_interface_subclass)    (MMKernelDevice *self);
@@ -77,6 +79,8 @@ const gchar *mm_kernel_device_get_name        (MMKernelDevice *self);
 const gchar *mm_kernel_device_get_driver      (MMKernelDevice *self);
 const gchar *mm_kernel_device_get_sysfs_path  (MMKernelDevice *self);
 
+const gchar *mm_kernel_device_get_wwandev_sysfs_path  (MMKernelDevice *self);
+
 gint         mm_kernel_device_get_interface_number      (MMKernelDevice *self);
 gint         mm_kernel_device_get_interface_class       (MMKernelDevice *self);
 gint         mm_kernel_device_get_interface_subclass    (MMKernelDevice *self);