[PATCH v5 1/1] USB: core: let USB device know device node
Peter Chen
peter.chen at nxp.com
Tue Feb 16 00:42:52 PST 2016
From: Peter Chen <peter.chen at freescale.com>
Although most of USB devices are hot-plug's, there are still some devices
are hard wired on the board, eg, for HSIC and SSIC interface USB devices.
If these kinds of USB devices are multiple functions, and they can supply
other interfaces like i2c, gpios for other devices, we may need to
describe these at device tree.
In this commit, it uses "reg" in dts as physical port number to match
the phyiscal port number decided by USB core, if they are the same,
then the device node is for the device we are creating for USB core.
Signed-off-by: Peter Chen <peter.chen at freescale.com>
---
Changes for v5:
- Refine the code how to get the device node at usb_alloc_dev according
to Alan's comment.
- Point out "usbVID,PID" is the recommented compatible, and others
compatibles at binding doc could also be used.
Changes for v4:
- The range of "reg" should be 1-31, changing device node address
style as in lower case hexadecimal with leading zeroes suppressed
[binding doc, usb-device.txt]
- Improve the example at binding doc, it describes node from the top
(the controller)
- Delete the struct of_node * within struct usb_device
- Using usb_hcd_find_raw_port_number to get raw port number under root
hub port
Changes for v3:
- typo: s/descirbe/describe/
Changes for v2:
- Fix build error reported by kbuild robot, lack of "static" for
inline usb_of_get_child_node
- Fix typo, "devcie_node" -> "device_node"
- Add kernel-doc for of_node at struct usb_device
Changes from RFC:
- Fix the error address for binding doc, and add compatible for binding doc
- Change get child node API from "usb_of_find_node" to
"usb_of_get_child_node"
- Delete unecessary header files
- One typo
.../devicetree/bindings/usb/usb-device.txt | 26 ++++++++++++
drivers/usb/core/Makefile | 2 +-
drivers/usb/core/of.c | 47 ++++++++++++++++++++++
drivers/usb/core/usb.c | 10 +++++
include/linux/usb/of.h | 7 ++++
5 files changed, 91 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/usb/usb-device.txt
create mode 100644 drivers/usb/core/of.c
diff --git a/Documentation/devicetree/bindings/usb/usb-device.txt b/Documentation/devicetree/bindings/usb/usb-device.txt
new file mode 100644
index 0000000..a997a23
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/usb-device.txt
@@ -0,0 +1,26 @@
+Generic USB Device Properties
+
+Usually, we only use device tree for hard wired USB device.
+The reference binding doc is from:
+http://www.firmware.org/1275/bindings/usb/usb-1_0.ps
+
+Required properties:
+- compatible: usbVID,PID. The other compatible strings from the above
+ standard binding could also be used, but a device adhering to this
+ binding may leave out all except for usbVID,PID.
+- reg: the port number which this device is connecting to, the range
+ is 1-31.
+
+Example:
+
+&usb1 {
+ status = "okay";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ hub: genesys at 1 {
+ compatible = "usb05e3,0608";
+ reg = <1>;
+ };
+}
diff --git a/drivers/usb/core/Makefile b/drivers/usb/core/Makefile
index 2f6f932..9780877 100644
--- a/drivers/usb/core/Makefile
+++ b/drivers/usb/core/Makefile
@@ -5,7 +5,7 @@
usbcore-y := usb.o hub.o hcd.o urb.o message.o driver.o
usbcore-y += config.o file.o buffer.o sysfs.o endpoint.o
usbcore-y += devio.o notify.o generic.o quirks.o devices.o
-usbcore-y += port.o
+usbcore-y += port.o of.o
usbcore-$(CONFIG_PCI) += hcd-pci.o
usbcore-$(CONFIG_ACPI) += usb-acpi.o
diff --git a/drivers/usb/core/of.c b/drivers/usb/core/of.c
new file mode 100644
index 0000000..2289700
--- /dev/null
+++ b/drivers/usb/core/of.c
@@ -0,0 +1,47 @@
+/*
+ * of.c The helpers for hcd device tree support
+ *
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Author: Peter Chen <peter.chen at freescale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/of.h>
+
+/**
+ * usb_of_get_child_node - Find the device node match port number
+ * @parent: the parent device node
+ * @portnum: the port number which device is connecting
+ *
+ * Find the node from device tree according to its port number.
+ *
+ * Return: On success, a pointer to the device node, %NULL on failure.
+ */
+struct device_node *usb_of_get_child_node(struct device_node *parent,
+ int portnum)
+{
+ struct device_node *node;
+ u32 port;
+
+ for_each_child_of_node(parent, node) {
+ if (!of_property_read_u32(node, "reg", &port)) {
+ if (port == portnum)
+ return node;
+ }
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(usb_of_get_child_node);
+
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 16ade41..d9b2564 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -36,6 +36,7 @@
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/debugfs.h>
+#include <linux/usb/of.h>
#include <asm/io.h>
#include <linux/scatterlist.h>
@@ -470,6 +471,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
dev->route = 0;
dev->dev.parent = bus->controller;
+ dev->dev.of_node = bus->controller->of_node;
dev_set_name(&dev->dev, "usb%d", bus->busnum);
root_hub = 1;
} else {
@@ -494,6 +496,14 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
dev->dev.parent = &parent->dev;
dev_set_name(&dev->dev, "%d-%s", bus->busnum, dev->devpath);
+ if (!parent->parent) {
+ /* device under root hub's port */
+ port1 = usb_hcd_find_raw_port_number(usb_hcd,
+ port1);
+ }
+ dev->dev.of_node = usb_of_get_child_node(parent->dev.of_node,
+ port1);
+
/* hub driver sets up TT records */
}
diff --git a/include/linux/usb/of.h b/include/linux/usb/of.h
index 974bce9..de3237f 100644
--- a/include/linux/usb/of.h
+++ b/include/linux/usb/of.h
@@ -16,6 +16,8 @@ enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np);
bool of_usb_host_tpl_support(struct device_node *np);
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);
#else
static inline enum usb_dr_mode
of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
@@ -31,6 +33,11 @@ static inline int of_usb_update_otg_caps(struct device_node *np,
{
return 0;
}
+static inline struct device_node *usb_of_get_child_node
+ (struct device_node *parent, int portnum)
+{
+ return NULL;
+}
#endif
#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_USB_SUPPORT)
--
1.9.1
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