usb: of: add functions to bind a companion controller

EHCI controllers will have a companion controller. However, on platform
bus, there was difficult to bind them in previous code. So, this
patch adds helper functions to bind them using a "companion" property.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
index bfadeb1..0a74ab8 100644 (file)
--- a/Documentation/devicetree/bindings/usb/generic.txt
+++ b/Documentation/devicetree/bindings/usb/generic.txt
@@ -22,6 +22,7 @@ Optional properties:
                        property is used if any real OTG features(HNP/SRP/ADP)
                        is enabled, if ADP is required, otg-rev should be
                        0x0200 or above.
+ - companion: phandle of a companion
  - hnp-disable: tells OTG controllers we want to disable OTG HNP, normally HNP
                        is the basic function of real OTG except you want it
                        to be a srp-capable only B device.

diff --git a/drivers/usb/core/of.c b/drivers/usb/core/of.c
index 3de4f88..d787f19 100644 (file)
--- a/drivers/usb/core/of.c
+++ b/drivers/usb/core/of.c
@@ -18,6 +18,7 @@
  */
 
 #include <linux/of.h>
+#include <linux/of_platform.h>
 #include <linux/usb/of.h>
 
 /**
@@ -46,3 +47,25 @@ struct device_node *usb_of_get_child_node(struct device_node *parent,
 }
 EXPORT_SYMBOL_GPL(usb_of_get_child_node);
 
+/**
+ * usb_of_get_companion_dev - Find the companion device
+ * @dev: the device pointer to find a companion
+ *
+ * Find the companion device from platform bus.
+ *
+ * Return: On success, a pointer to the companion device, %NULL on failure.
+ */
+struct device *usb_of_get_companion_dev(struct device *dev)
+{
+       struct device_node *node;
+       struct platform_device *pdev = NULL;
+
+       node = of_parse_phandle(dev->of_node, "companion", 0);
+       if (node)
+               pdev = of_find_device_by_node(node);
+
+       of_node_put(node);
+
+       return pdev ? &pdev->dev : NULL;
+}
+EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);

diff --git a/include/linux/usb/of.h b/include/linux/usb/of.h
index 5ff9032..4031f47 100644 (file)
--- a/include/linux/usb/of.h
+++ b/include/linux/usb/of.h
@@ -18,6 +18,7 @@ int of_usb_update_otg_caps(struct device_node *np,
                        struct usb_otg_caps *otg_caps);
 struct device_node *usb_of_get_child_node(struct device_node *parent,
                        int portnum);
+struct device *usb_of_get_companion_dev(struct device *dev);
 #else
 static inline enum usb_dr_mode
 of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
@@ -38,6 +39,10 @@ static inline struct device_node *usb_of_get_child_node
 {
        return NULL;
 }
+static inline struct device *usb_of_get_companion_dev(struct device *dev)
+{
+       return NULL;
+}
 #endif
 
 #if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_USB_SUPPORT)