Re: [RFC PATCH 1/2] USB: core: let USB device know device node
From: Alan Stern <hidden>
Date: 2016-01-08 22:50:13
Also in:
linux-arm-kernel
On Fri, 8 Jan 2016, Peter Chen wrote:
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 descirbe these at device tree. In this commit, it uses "reg" in dts as port number to match the 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 <redacted> ---
+#include <linux/module.h> +#include <linux/moduleparam.h>
Do you need those two #include's?
+#include <linux/of.h> + +/** + * usb_of_find_node - Find the device node match port number + * @dev: the parent device node
The parameter is actually named "parent".
+ * @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_find_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_find_node);
+quoted hunk
diff --git a/include/linux/usb.h b/include/linux/usb.h index 89533ba..a3a0b07 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h@@ -21,6 +21,7 @@ #include <linux/sched.h> /* for current && schedule_timeout */ #include <linux/mutex.h> /* for struct mutex */ #include <linux/pm_runtime.h> /* for runtime PM */ +#include <linux/of.h> /* for device tree */
I think you don't need this line. You can simply write: struct device_node; just like the two lines below.
quoted hunk
struct usb_device; struct usb_driver;@@ -616,6 +617,7 @@ struct usb_device { struct usb3_lpm_parameters u1_params; struct usb3_lpm_parameters u2_params; unsigned lpm_disable_count; + struct device_node *of_node; /* associated device tree node */ }; #define to_usb_device(d) container_of(d, struct usb_device, dev)
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