On Mon, May 29, 2017 at 04:15:36PM +0200, Johan Hovold wrote:
> On Mon, May 29, 2017 at 11:01:52AM +0200, Martin Fuzzey wrote:
> > However my larger question is that I don't see how to associate a DT
> > node with a USB *interface* rather than a USB *device*.
>
> I started looking into this a while back but got interrupted. I have
> some preliminary code, mostly lacking associated documentation.
> I'll post my work as an RFC shortly, and add you on CC.
Here's a preview.
Johan
>From 5db86d55975ef0e047ab3157d59de0869aa88acf Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@xxxxxxxxxx>
Date: Fri, 21 Apr 2017 19:55:59 +0200
Subject: [RFC] USB: of: add support for interface nodes
Add support for USB-interface OF-nodes. Interfaces are children of
USB-device nodes and are identified by a configuration value and an
interface number:
&usb1 { /* root hub */
device@1 { /* device at port 1 */
compatible = <usb1234,5678>;
reg = <1>;
device@1,0 { /* interface 0 of configuration 1 */
compatible = <usbif1234,5678,config1.0>;
reg = <1 0>;
};
};
};
FIXME: documentation, mention spec
Not-Signed-off-yet-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/core/message.c | 14 +++++++++-----
drivers/usb/core/of.c | 30 ++++++++++++++++++++++++++++++
include/linux/usb/of.h | 9 +++++++++
3 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 4c38ea41ae96..921b66e34a03 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -18,6 +18,7 @@
#include <linux/usb/cdc.h>
#include <linux/usb/quirks.h>
#include <linux/usb/hcd.h> /* for usbcore internals */
+#include <linux/usb/of.h>
#include <asm/byteorder.h>
#include "usb.h"
@@ -1548,6 +1549,7 @@ static void usb_release_interface(struct device *dev)
kref_put(&intfc->ref, usb_release_interface_cache);
usb_put_dev(interface_to_usbdev(intf));
+ of_node_put(dev->of_node);
kfree(intf);
}
@@ -1833,6 +1835,7 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
struct usb_interface_cache *intfc;
struct usb_interface *intf;
struct usb_host_interface *alt;
+ u8 ifnum;
cp->interface[i] = intf = new_interfaces[i];
intfc = cp->intf_cache[i];
@@ -1851,11 +1854,13 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
if (!alt)
alt = &intf->altsetting[0];
- intf->intf_assoc =
- find_iad(dev, cp, alt->desc.bInterfaceNumber);
+ ifnum = alt->desc.bInterfaceNumber;
+ intf->intf_assoc = find_iad(dev, cp, ifnum);
intf->cur_altsetting = alt;
usb_enable_interface(dev, intf, true);
intf->dev.parent = &dev->dev;
+ intf->dev.of_node = usb_of_find_interface_node(dev,
+ configuration, ifnum);
intf->dev.driver = NULL;
intf->dev.bus = &usb_bus_type;
intf->dev.type = &usb_if_device_type;
@@ -1870,9 +1875,8 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
intf->minor = -1;
device_initialize(&intf->dev);
pm_runtime_no_callbacks(&intf->dev);
- dev_set_name(&intf->dev, "%d-%s:%d.%d",
- dev->bus->busnum, dev->devpath,
- configuration, alt->desc.bInterfaceNumber);
+ dev_set_name(&intf->dev, "%d-%s:%d.%d", dev->bus->busnum,
+ dev->devpath, configuration, ifnum);
usb_get_dev(dev);
}
kfree(new_interfaces);
diff --git a/drivers/usb/core/of.c b/drivers/usb/core/of.c
index 17a4af02cf5b..87e257eb8eeb 100644
--- a/drivers/usb/core/of.c
+++ b/drivers/usb/core/of.c
@@ -51,6 +51,36 @@ struct device_node *usb_of_get_child_node(struct device_node *parent,
EXPORT_SYMBOL_GPL(usb_of_get_child_node);
/**
+ * usb_of_find_interface_node() - find a USB-interface device node
+ * @udev: USB device of interface
+ * @config: configuration value
+ * @ifnum: interface number
+ *
+ * Look up the device node of an interface given its USB device, configuration
+ * value, and interface number.
+ *
+ * Return: A pointer to the node with incremented refcount if found, or
+ * %NULL otherwise.
+ */
+struct device_node *usb_of_find_interface_node(struct usb_device *udev,
+ u8 config, u8 ifnum)
+{
+ struct device_node *node;
+ u32 reg[2];
+
+ for_each_child_of_node(udev->dev.of_node, node) {
+ if (of_property_read_u32_array(node, "reg", reg, 2))
+ continue;
+
+ if (reg[0] == config && reg[1] == ifnum)
+ return node;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(usb_of_find_interface_node);
+
+/**
* usb_of_get_companion_dev - Find the companion device
* @dev: the device pointer to find a companion
*
diff --git a/include/linux/usb/of.h b/include/linux/usb/of.h
index 4031f47629ec..27d9ed28e734 100644
--- a/include/linux/usb/of.h
+++ b/include/linux/usb/of.h
@@ -11,6 +11,8 @@
#include <linux/usb/otg.h>
#include <linux/usb/phy.h>
+struct usb_device;
+
#if IS_ENABLED(CONFIG_OF)
enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0);
bool of_usb_host_tpl_support(struct device_node *np);
@@ -18,6 +20,8 @@ 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_node *usb_of_find_interface_node(struct usb_device *udev,
+ u8 config, u8 ifnum);
struct device *usb_of_get_companion_dev(struct device *dev);
#else
static inline enum usb_dr_mode
@@ -39,6 +43,11 @@ static inline struct device_node *usb_of_get_child_node
{
return NULL;
}
+struct device_node *usb_of_find_interface_node(struct usb_device *udev,
+ u8 config, u8 ifnum);
+{
+ return NULL;
+}
static inline struct device *usb_of_get_companion_dev(struct device *dev)
{
return NULL;
--
2.13.0
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