[RFC PATCH 2/2] usb: Example for how to use device node at usb device driver

[Peter Chen]

In this example, we take HUB driver as an example to show how
to get properties in USB device driver if this device has device
node.

Signed-off-by: Peter Chen <peter.chen at freescale.com>
---
 arch/arm/boot/dts/imx6sx-sdb.dtsi | 9 +++++++++
 drivers/usb/core/hub.c            | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/arm/boot/dts/imx6sx-sdb.dtsi b/arch/arm/boot/dts/imx6sx-sdb.dtsi
index 94ac400..fe0fd95 100644
--- a/arch/arm/boot/dts/imx6sx-sdb.dtsi
+++ b/arch/arm/boot/dts/imx6sx-sdb.dtsi
@@ -275,6 +275,15 @@
 	vbus-supply = <&reg_usb_otg2_vbus>;
 	dr_mode = "host";
 	status = "okay";
+
+	#address-cells = <1>;
+	#size-cells = <0>;
+	hub: genesys at 01 {
+		compatible = "05e3,0608";
+		reg = <0x01>;
+		delay-duration-us = <50>;
+	};
+
 };
 
 &usdhc2 {
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 4c77001..1babfd4 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -27,6 +27,7 @@
 #include <linux/random.h>
 #include <linux/pm_qos.h>
 #include <linux/of_platform.h>
+#include <linux/of.h>
 
 #include <asm/uaccess.h>
 #include <asm/byteorder.h>
@@ -1748,6 +1749,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
 	struct usb_device *hdev;
 	struct usb_hub *hub;
 	int ret;
+	u32 duration_us = 0;
 
 	desc = intf->cur_altsetting;
 	hdev = interface_to_usbdev(intf);
@@ -1873,6 +1875,12 @@ descriptor_error:
 		return ret;
 	}
 
+	of_property_read_u32(hdev->dev.of_node, "delay-duration-us", &duration_us);
+	if (duration_us > 0) {
+		usleep_range(duration_us, duration_us + 10);
+		dev_info(&hdev->dev, "The delay is %d us\n", duration_us);
+	}
+
 	if (hub_configure(hub, endpoint) >= 0)
 		return 0;
 
-- 
1.9.1