ACK: [PATCH] USB: core: let USB device know device node
Colin Ian King
colin.king at canonical.com
Thu Oct 18 13:30:31 UTC 2018
On 18/10/2018 14:24, Paolo Pisati wrote:
> From: Peter Chen <peter.chen at freescale.com>
>
> BugLink: http://bugs.launchpad.net/bugs/1798578
>
> 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>
> Acked-by: Philipp Zabel <p.zabel at pengutronix.de>
> Acked-by: Alan Stern <stern at rowland.harvard.edu>
> Acked-by: Rob Herring <robh at kernel.org>
> Acked-by: Arnd Bergmann <arnd at arndb.de>
> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> (cherry picked from commit 69bec725985324e79b1c47ea287815ac4ddb0521)
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>
> ---
> .../devicetree/bindings/usb/usb-device.txt | 28 +++++++++++++
> 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, 93 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..1c35e7b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/usb-device.txt
> @@ -0,0 +1,28 @@
> +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 textual representation of VID, PID shall
> + be in lower case hexadecimal with leading zeroes suppressed. 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 = "usb5e3,608";
> + 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 f8bbd0b..3fdb2f8 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>
> @@ -469,6 +470,7 @@ 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 {
> @@ -493,6 +495,14 @@ 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 c3fe9e4..bc7644b 100644
> --- a/include/linux/usb/of.h
> +++ b/include/linux/usb/of.h
> @@ -15,6 +15,8 @@
> 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 bool of_usb_host_tpl_support(struct device_node *np)
> {
> @@ -25,6 +27,11 @@ 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)
>
Clean cherry pick, fixes the issue, limited regression potential and has
been tested, so..
Acked-by: Colin Ian King <colin.king at canonical.com>
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