slimbus: core: add of_slim_device_get() helper

On SLIMBus controllers like Qcom NGD(non ported device), controller
can request logical address once the remote side is powered, having a
helper function like this to explicitly enumerate the bus is helpful.
Also codec drivers which are taking to interface device would need
such a helper too.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/drivers/slimbus/core.c b/drivers/slimbus/core.c
index 7ddfc675b131..88248a4ecad9 100644
--- a/drivers/slimbus/core.c
+++ b/drivers/slimbus/core.c
@@ -356,6 +356,45 @@ struct slim_device *slim_get_device(struct slim_controller *ctrl,
 }
 EXPORT_SYMBOL_GPL(slim_get_device);
 
+static int of_slim_match_dev(struct device *dev, void *data)
+{
+        struct device_node *np = data;
+        struct slim_device *sbdev = to_slim_device(dev);
+
+        return (sbdev->dev.of_node == np);
+}
+
+static struct slim_device *of_find_slim_device(struct slim_controller *ctrl,
+                                               struct device_node *np)
+{
+        struct slim_device *sbdev;
+        struct device *dev;
+
+        dev = device_find_child(ctrl->dev, np, of_slim_match_dev);
+        if (dev) {
+                sbdev = to_slim_device(dev);
+                return sbdev;
+        }
+
+        return NULL;
+}
+
+/**
+ * of_slim_get_device() - get handle to a device using dt node.
+ *
+ * @ctrl: Controller on which this device will be added/queried
+ * @np: node pointer to device
+ *
+ * Return: pointer to a device if it has already reported. Creates a new
+ * device and returns pointer to it if the device has not yet enumerated.
+ */
+struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
+                                       struct device_node *np)
+{
+        return of_find_slim_device(ctrl, np);
+}
+EXPORT_SYMBOL_GPL(of_slim_get_device);
+
 static int slim_device_alloc_laddr(struct slim_device *sbdev,
                                    bool report_present)
 {