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* [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver
@ 2021-05-11 22:52 Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 1/5] dt-bindings: usb: Add binding for Realtek RTS5411 hub controller Matthias Kaehlcke
                   ` (6 more replies)
  0 siblings, 7 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-11 22:52 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand
  Cc: Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Matthias Kaehlcke,
	Al Cooper, Alexander A. Klimov, Andy Gross, Bjorn Andersson,
	Christian Lamparter, Colin Ian King, Dmitry Osipenko,
	Fabio Estevam, Masahiro Yamada, Mathias Nyman, Vinod Koul,
	linux-arm-msm

This series adds:
- the onboard_usb_hub_driver
- glue in the xhci-plat driver to create the onboard_usb_hub
  platform device if needed
- a device tree binding for the Realtek RTS5411 USB hub controller
- device tree changes that add RTS5411 entries for the QCA SC7180
  based boards trogdor and lazor
- a couple of stubs for platform device functions to avoid
  unresolved symbols with certain kernel configs

The main issue the driver addresses is that a USB hub needs to be
powered before it can be discovered. For discrete onboard hubs (an
example for such a hub is the Realtek RTS5411) this is often solved
by supplying the hub with an 'always-on' regulator, which is kind
of a hack. Some onboard hubs may require further initialization
steps, like changing the state of a GPIO or enabling a clock, which
requires even more hacks. This driver creates a platform device
representing the hub which performs the necessary initialization.
Currently it only supports switching on a single regulator, support
for multiple regulators or other actions can be added as needed.
Different initialization sequences can be supported based on the
compatible string.

Besides performing the initialization the driver can be configured
to power the hub off during system suspend. This can help to extend
battery life on battery powered devices which have no requirements
to keep the hub powered during suspend. The driver can also be
configured to leave the hub powered when a wakeup capable USB device
is connected when suspending, and power it off otherwise.

Changes in v10:
- always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
- keep 'regulator-boot-on' property for pp3300_hub

Changes in v9:
- added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
  USB_PLATFORM_XHCI

Changes in v7:
- updated DT binding
- series rebased on qcom/arm64-for-5.13

Changes in v6:
- updated summary

Changes in v5:
- cover letter added

Matthias Kaehlcke (5):
  dt-bindings: usb: Add binding for Realtek RTS5411 hub controller
  USB: misc: Add onboard_usb_hub driver
  of/platform: Add stubs for of_platform_device_create/destroy()
  usb: host: xhci-plat: Create platform device for onboard hubs in
    probe()
  arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub

 .../sysfs-bus-platform-onboard-usb-hub        |   8 +
 .../bindings/usb/realtek,rts5411.yaml         |  62 +++
 MAINTAINERS                                   |   7 +
 .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
 .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  11 +-
 .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
 drivers/usb/host/Kconfig                      |   1 +
 drivers/usb/host/xhci-plat.c                  |  16 +
 drivers/usb/misc/Kconfig                      |  17 +
 drivers/usb/misc/Makefile                     |   1 +
 drivers/usb/misc/onboard_usb_hub.c            | 415 ++++++++++++++++++
 include/linux/of_platform.h                   |  22 +-
 include/linux/usb/hcd.h                       |   2 +
 include/linux/usb/onboard_hub.h               |  15 +
 15 files changed, 600 insertions(+), 34 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
 create mode 100644 Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
 create mode 100644 drivers/usb/misc/onboard_usb_hub.c
 create mode 100644 include/linux/usb/onboard_hub.h

-- 
2.31.1.607.g51e8a6a459-goog


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [PATCH v10 1/5] dt-bindings: usb: Add binding for Realtek RTS5411 hub controller
  2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
@ 2021-05-11 22:52 ` Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (5 subsequent siblings)
  6 siblings, 0 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-11 22:52 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand
  Cc: Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Matthias Kaehlcke,
	Rob Herring

The Realtek RTS5411 is a USB 3.0 hub controller with 4 ports.

This initial version of the binding only describes USB related
aspects of the RTS5411, it does not cover the option of
connecting the controller as an i2c slave.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---

Changes in v10:
- none

Changes in v9:
- added Rob's 'Reviewed-by' tag

Changes in v8:
- added entry for 'reg'
- marked 'companion-hub' as required
- changed node name of USB controller to 'usb'

Changes in v7:
- added type ref for 'companion-hub' property

Changes in v6:
- Realtek binding instead of generic onboard_usb_hub
- added 'companion-hub' property
- added reference to 'usb-device.yaml'
- 'fixed' indentation of compatible entries to keep yamllint happy
- added 'additionalProperties' entry
- updated commit message

Changes in v5:
- updated 'title'
- only use standard USB compatible strings
- deleted 'usb_hub' node
- renamed 'usb_controller' node to 'usb-controller'
- removed labels from USB nodes
- added 'vdd-supply' to USB nodes

Changes in v4:
- none

Changes in v3:
- updated commit message
- removed recursive reference to $self
- adjusted 'compatible' definition to support multiple entries
- changed USB controller phandle to be a node

Changes in v2:
- removed 'wakeup-source' and 'power-off-in-suspend' properties
- consistently use spaces for indentation in example

 .../bindings/usb/realtek,rts5411.yaml         | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/realtek,rts5411.yaml

diff --git a/Documentation/devicetree/bindings/usb/realtek,rts5411.yaml b/Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
new file mode 100644
index 000000000000..04ee255eb4f0
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/realtek,rts5411.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Binding for the Realtek RTS5411 USB 3.0 hub controller
+
+maintainers:
+  - Matthias Kaehlcke <mka@chromium.org>
+
+allOf:
+  - $ref: usb-device.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - usbbda,5411
+          - usbbda,411
+
+  reg: true
+
+  vdd-supply:
+    description:
+      phandle to the regulator that provides power to the hub.
+
+  companion-hub:
+    $ref: '/schemas/types.yaml#/definitions/phandle'
+    description:
+      phandle to the companion hub on the controller.
+
+required:
+  - companion-hub
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    usb {
+        dr_mode = "host";
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        /* 2.0 hub on port 1 */
+        hub_2_0: hub@1 {
+            compatible = "usbbda,5411";
+            reg = <1>;
+            vdd-supply = <&pp3300_hub>;
+            companion-hub = <&hub_3_0>;
+        };
+
+        /* 3.0 hub on port 2 */
+        hub_3_0: hub@2 {
+            compatible = "usbbda,411";
+            reg = <2>;
+            vdd-supply = <&pp3300_hub>;
+            companion-hub = <&hub_2_0>;
+        };
+    };
-- 
2.31.1.607.g51e8a6a459-goog


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 1/5] dt-bindings: usb: Add binding for Realtek RTS5411 hub controller Matthias Kaehlcke
@ 2021-05-11 22:52 ` Matthias Kaehlcke
  2021-05-18 17:05   ` Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 3/5] of/platform: Add stubs for of_platform_device_create/destroy() Matthias Kaehlcke
                   ` (4 subsequent siblings)
  6 siblings, 1 reply; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-11 22:52 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand
  Cc: Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Matthias Kaehlcke,
	Al Cooper, Alexander A. Klimov, Masahiro Yamada

The main issue this driver addresses is that a USB hub needs to be
powered before it can be discovered. For discrete onboard hubs (an
example for such a hub is the Realtek RTS5411) this is often solved
by supplying the hub with an 'always-on' regulator, which is kind
of a hack. Some onboard hubs may require further initialization
steps, like changing the state of a GPIO or enabling a clock, which
requires even more hacks. This driver creates a platform device
representing the hub which performs the necessary initialization.
Currently it only supports switching on a single regulator, support
for multiple regulators or other actions can be added as needed.
Different initialization sequences can be supported based on the
compatible string.

Besides performing the initialization the driver can be configured
to power the hub off during system suspend. This can help to extend
battery life on battery powered devices which have no requirements
to keep the hub powered during suspend. The driver can also be
configured to leave the hub powered when a wakeup capable USB device
is connected when suspending, and power it off otherwise.

Technically the driver consists of two drivers, the platform driver
described above and a very thin USB driver that subclasses the
generic driver. The purpose of this driver is to provide the platform
driver with the USB devices corresponding to the hub(s) (a hub
controller may provide multiple 'logical' hubs, e.g. one to support
USB 2.0 and another for USB 3.x).

Note: the driver currently only works with hubs connected directly
to a root hub, but it could be extended to support other
configurations if needed.

Co-developed-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---

Changes in v10:
- always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m

Changes in v9:
- none

Changes in v8:
- none

Changes in v7:
- don't declare stub for of_is_onboard_usb_hub() when
  CONFIG_COMPILE_TEST is defined

Changes in v6:
- use 'companion-hub' to locate the platform device, instead of
  scanning through the nodes of the parent
- added ABI documentation for 'always_powered_in_suspend'
- sysfs_emit() instead of sprintf() in always_powered_in_suspend_show()
- register sysfs attribute through driver.dev_groups
- evaluate return value of driver_attach() in _probe()
- use dev_warn() instead of WARN_ON() in _probe()
- include 'onboard_hub.h'

Changes in v5:
- the platform device is now instantiated from the same DT node
  as the 'primary' USB hub device
  - use the USB compatible strings for the platform device
  - refactored _find_onboard_hub() to search the parents child
    nodes for a platform device with a matching compatible string
  - added exported function of_is_onboard_usb_hub() to allow other
    drivers (like xhci_plat) to check if one of their child DT nodes
    is a supported hub
- use late suspend to make sure info about wakeup enabled descendants
  is updated
- call driver_attach() for the USB driver in onboard_hub_probe() to
  make sure the driver is re-attached after the device_release_driver()
  calls in onboard_hub_remove()
- renamed sysfs attribute 'power_off_in_suspend' to
  'always_powered_in_suspend'
- added sysfs symlinks between platform device and USB devices
- marked 'onboard_hub_pm_ops' as __maybe_unused
- removed 'realtek' compatible string which is not needed at this
  point
- fix log for regulator_disable() failure

Changes in v4:
- updated Kconfig documentation
- changed the loop in onboard_hub_remove() to release the hub lock
  before unbinding the USB device and make self deadlock prevention
  less clunky
- fixed return value in onboard_hub_usbdev_probe()
- added entry to MAINTAINERS file

Changes in v3:
- updated the commit message
- updated description in Kconfig
- remove include of 'core/usb.h'
- use 'is_powered_on' flag instead of 'has_wakeup_capable_descendants'
- added 'going_away' flag to struct onboard_hub
  - don't allow adding new USB devices when the platform device is going away
  - don't bother with deleting the list item in onboard_hub_remove_usbdev()
    when the platform device is going away
- don't assume in onboard_hub_suspend() that all USB hub devices are
  connected to the same controller
- removed unnecessary devm_kfree() from onboard_hub_remove_usbdev()
- fixed error handling in onboard_hub_remove_usbdev()
- use kstrtobool() instead of strtobool() in power_off_in_suspend_store()
- unbind USB devices in onboard_hub_remove() to avoid dangling references
  to the platform device
- moved put_device() for platform device to _find_onboard_hub()
- changed return value of onboard_hub_remove_usbdev() to void
- evaluate return value of onboard_hub_add_usbdev()
- register 'power_off_in_suspend' as managed device attribute
- use USB_DEVICE macro instead manual initialization
- add unwinding to onboard_hub_init()
- updated MODULE_DESCRIPTION
- use module_init() instead of device_initcall()

Changes in v2:
- check wakeup enabled state of the USB controller instead of
  using 'wakeup-source' property
- use sysfs attribute instead of DT property to determine if
  the hub should be powered off at all during system suspend
- added missing brace in onboard_hub_suspend()
- updated commit message
- use pm_ptr for pm_ops as suggested by Alan

Changes in v1:
- renamed the driver to 'onboard_usb_hub'
- single file for platform and USB driver
- USB hub devices register with the platform device
  - the DT includes a phandle of the platform device
- the platform device now controls when power is turned off
- the USB driver became a very thin subclass of the generic USB
  driver
- enabled autosuspend support

 .../sysfs-bus-platform-onboard-usb-hub        |   8 +
 MAINTAINERS                                   |   7 +
 drivers/usb/misc/Kconfig                      |  17 +
 drivers/usb/misc/Makefile                     |   1 +
 drivers/usb/misc/onboard_usb_hub.c            | 415 ++++++++++++++++++
 include/linux/usb/onboard_hub.h               |  15 +
 6 files changed, 463 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
 create mode 100644 drivers/usb/misc/onboard_usb_hub.c
 create mode 100644 include/linux/usb/onboard_hub.h

diff --git a/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub b/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
new file mode 100644
index 000000000000..e981d83648e6
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
@@ -0,0 +1,8 @@
+What:		/sys/bus/platform/devices/<dev>/always_powered_in_suspend
+Date:		March 2021
+KernelVersion:	5.13
+Contact:	Matthias Kaehlcke <matthias@kaehlcke.net>
+		linux-usb@vger.kernel.org
+Description:
+		(RW) Controls whether the USB hub remains always powered
+		during system suspend or not.
\ No newline at end of file
diff --git a/MAINTAINERS b/MAINTAINERS
index d92f85ca831d..882ae6e378c5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13297,6 +13297,13 @@ S:	Maintained
 T:	git git://linuxtv.org/media_tree.git
 F:	drivers/media/i2c/ov9734.c
 
+ONBOARD USB HUB DRIVER
+M:	Matthias Kaehlcke <mka@chromium.org>
+L:	linux-usb@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml
+F:	drivers/usb/misc/onboard_usb_hub.c
+
 ONENAND FLASH DRIVER
 M:	Kyungmin Park <kyungmin.park@samsung.com>
 L:	linux-mtd@lists.infradead.org
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 8f1144359012..f534269fbb20 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -284,3 +284,20 @@ config BRCM_USB_PINMAP
 	  This option enables support for remapping some USB external
 	  signals, which are typically on dedicated pins on the chip,
 	  to any gpio.
+
+config USB_ONBOARD_HUB
+	tristate "Onboard USB hub support"
+	depends on OF || COMPILE_TEST
+	help
+	  Say Y here if you want to support discrete onboard USB hubs that
+	  don't require an additional control bus for initialization, but
+	  need some nontrivial form of initialization, such as enabling a
+	  power regulator. An example for such a hub is the Realtek
+	  RTS5411.
+
+	  The driver can be configured to turn off the power of the hub
+	  during system suspend. This may reduce power consumption while
+	  the system is suspended.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called onboard_usb_hub.
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index 5f4e598573ab..2c5aec6f1b26 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -32,3 +32,4 @@ obj-$(CONFIG_USB_CHAOSKEY)		+= chaoskey.o
 obj-$(CONFIG_USB_SISUSBVGA)		+= sisusbvga/
 obj-$(CONFIG_USB_LINK_LAYER_TEST)	+= lvstest.o
 obj-$(CONFIG_BRCM_USB_PINMAP)		+= brcmstb-usb-pinmap.o
+obj-$(CONFIG_USB_ONBOARD_HUB)		+= onboard_usb_hub.o
diff --git a/drivers/usb/misc/onboard_usb_hub.c b/drivers/usb/misc/onboard_usb_hub.c
new file mode 100644
index 000000000000..db926699a5ec
--- /dev/null
+++ b/drivers/usb/misc/onboard_usb_hub.c
@@ -0,0 +1,415 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Driver for onboard USB hubs
+ *
+ * Copyright (c) 2020, Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/suspend.h>
+#include <linux/sysfs.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/onboard_hub.h>
+
+static struct usb_device_driver onboard_hub_usbdev_driver;
+
+/************************** Platform driver **************************/
+
+struct udev_node {
+	struct usb_device *udev;
+	struct list_head list;
+};
+
+struct onboard_hub {
+	struct regulator *vdd;
+	struct device *dev;
+	bool always_powered_in_suspend;
+	bool is_powered_on;
+	bool going_away;
+	struct list_head udev_list;
+	struct mutex lock;
+};
+
+static int onboard_hub_power_on(struct onboard_hub *hub)
+{
+	int err;
+
+	err = regulator_enable(hub->vdd);
+	if (err) {
+		dev_err(hub->dev, "failed to enable regulator: %d\n", err);
+		return err;
+	}
+
+	hub->is_powered_on = true;
+
+	return 0;
+}
+
+static int onboard_hub_power_off(struct onboard_hub *hub)
+{
+	int err;
+
+	err = regulator_disable(hub->vdd);
+	if (err) {
+		dev_err(hub->dev, "failed to disable regulator: %d\n", err);
+		return err;
+	}
+
+	hub->is_powered_on = false;
+
+	return 0;
+}
+
+static int __maybe_unused onboard_hub_suspend(struct device *dev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+	struct udev_node *node;
+	bool power_off;
+	int rc = 0;
+
+	if (hub->always_powered_in_suspend)
+		return 0;
+
+	power_off = true;
+
+	mutex_lock(&hub->lock);
+
+	list_for_each_entry(node, &hub->udev_list, list) {
+		if (!device_may_wakeup(node->udev->bus->controller))
+			continue;
+
+		if (usb_wakeup_enabled_descendants(node->udev)) {
+			power_off = false;
+			break;
+		}
+	}
+
+	mutex_unlock(&hub->lock);
+
+	if (power_off)
+		rc = onboard_hub_power_off(hub);
+
+	return rc;
+}
+
+static int __maybe_unused onboard_hub_resume(struct device *dev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+	int rc = 0;
+
+	if (!hub->is_powered_on)
+		rc = onboard_hub_power_on(hub);
+
+	return rc;
+}
+
+static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev)
+{
+	struct udev_node *node;
+	char link_name[64];
+	int ret = 0;
+
+	mutex_lock(&hub->lock);
+
+	if (hub->going_away) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	node = devm_kzalloc(hub->dev, sizeof(*node), GFP_KERNEL);
+	if (!node) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	node->udev = udev;
+
+	list_add(&node->list, &hub->udev_list);
+
+	snprintf(link_name, sizeof(link_name), "usb_dev.%s", dev_name(&udev->dev));
+	WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name));
+
+unlock:
+	mutex_unlock(&hub->lock);
+
+	return ret;
+}
+
+static void onboard_hub_remove_usbdev(struct onboard_hub *hub, struct usb_device *udev)
+{
+	struct udev_node *node;
+	char link_name[64];
+
+	snprintf(link_name, sizeof(link_name), "usb_dev.%s", dev_name(&udev->dev));
+	sysfs_remove_link(&hub->dev->kobj, link_name);
+
+	mutex_lock(&hub->lock);
+
+	list_for_each_entry(node, &hub->udev_list, list) {
+		if (node->udev == udev) {
+			list_del(&node->list);
+			break;
+		}
+	}
+
+	mutex_unlock(&hub->lock);
+}
+
+static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", hub->always_powered_in_suspend);
+}
+
+static ssize_t always_powered_in_suspend_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct onboard_hub *hub = dev_get_drvdata(dev);
+	bool val;
+	int ret;
+
+	ret = kstrtobool(buf, &val);
+	if (ret < 0)
+		return ret;
+
+	hub->always_powered_in_suspend = val;
+
+	return count;
+}
+static DEVICE_ATTR_RW(always_powered_in_suspend);
+
+static struct attribute *onboard_hub_attrs[] = {
+	&dev_attr_always_powered_in_suspend.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(onboard_hub);
+
+static int onboard_hub_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct onboard_hub *hub;
+	int err;
+
+	hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL);
+	if (!hub)
+		return -ENOMEM;
+
+	hub->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(hub->vdd))
+		return PTR_ERR(hub->vdd);
+
+	hub->dev = dev;
+	mutex_init(&hub->lock);
+	INIT_LIST_HEAD(&hub->udev_list);
+
+	dev_set_drvdata(dev, hub);
+
+	err = onboard_hub_power_on(hub);
+	if (err)
+		return err;
+
+	/*
+	 * The USB driver might have been detached from the USB devices by
+	 * onboard_hub_remove(), make sure to re-attach it if needed.
+	 */
+	err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver);
+	if (err) {
+		onboard_hub_power_off(hub);
+		return err;
+	}
+
+	return 0;
+}
+
+static int onboard_hub_remove(struct platform_device *pdev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(&pdev->dev);
+	struct udev_node *node;
+	struct usb_device *udev;
+
+	hub->going_away = true;
+
+	mutex_lock(&hub->lock);
+
+	/* unbind the USB devices to avoid dangling references to this device */
+	while (!list_empty(&hub->udev_list)) {
+		node = list_first_entry(&hub->udev_list, struct udev_node, list);
+		udev = node->udev;
+
+		/*
+		 * Unbinding the driver will call onboard_hub_remove_usbdev(),
+		 * which acquires hub->lock.  We must release the lock first.
+		 */
+		get_device(&udev->dev);
+		mutex_unlock(&hub->lock);
+		device_release_driver(&udev->dev);
+		put_device(&udev->dev);
+		mutex_lock(&hub->lock);
+	}
+
+	mutex_unlock(&hub->lock);
+
+	return onboard_hub_power_off(hub);
+}
+
+static const struct of_device_id onboard_hub_match[] = {
+	{ .compatible = "usbbda,411" },
+	{ .compatible = "usbbda,5411" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, onboard_hub_match);
+
+bool of_is_onboard_usb_hub(const struct device_node *np)
+{
+	return !!of_match_node(onboard_hub_match, np);
+}
+EXPORT_SYMBOL_GPL(of_is_onboard_usb_hub);
+
+static const struct dev_pm_ops __maybe_unused onboard_hub_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_hub_suspend, onboard_hub_resume)
+};
+
+static struct platform_driver onboard_hub_driver = {
+	.probe = onboard_hub_probe,
+	.remove = onboard_hub_remove,
+
+	.driver = {
+		.name = "onboard-usb-hub",
+		.of_match_table = onboard_hub_match,
+		.pm = pm_ptr(&onboard_hub_pm_ops),
+		.dev_groups = onboard_hub_groups,
+	},
+};
+
+/************************** USB driver **************************/
+
+#define VENDOR_ID_REALTEK	0x0bda
+
+/*
+ * Returns the onboard_hub platform device that is associated with the USB
+ * device passed as parameter.
+ */
+static struct onboard_hub *_find_onboard_hub(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct device_node *np;
+	phandle ph;
+
+	pdev = of_find_device_by_node(dev->of_node);
+	if (!pdev) {
+		if (of_property_read_u32(dev->of_node, "companion-hub", &ph)) {
+			dev_err(dev, "failed to read 'companion-hub' property\n");
+			return ERR_PTR(-EINVAL);
+		}
+
+		np = of_find_node_by_phandle(ph);
+		if (!np) {
+			dev_err(dev, "failed to find device node for companion hub\n");
+			return ERR_PTR(-EINVAL);
+		}
+
+		pdev = of_find_device_by_node(np);
+		of_node_put(np);
+
+		if (!pdev)
+			return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	put_device(&pdev->dev);
+
+	return dev_get_drvdata(&pdev->dev);
+}
+
+static int onboard_hub_usbdev_probe(struct usb_device *udev)
+{
+	struct device *dev = &udev->dev;
+	struct onboard_hub *hub;
+	int err;
+
+	/* ignore supported hubs without device tree node */
+	if (!dev->of_node)
+		return -ENODEV;
+
+	hub = _find_onboard_hub(dev);
+	if (IS_ERR(hub))
+		return PTR_ERR(hub);
+
+	dev_set_drvdata(dev, hub);
+
+	err = onboard_hub_add_usbdev(hub, udev);
+	if (err)
+		return err;
+
+	err = sysfs_create_link(&udev->dev.kobj, &hub->dev->kobj, "onboard_hub_dev");
+	if (err)
+		dev_warn(&udev->dev, "failed to create symlink to platform device: %d\n", err);
+
+	return 0;
+}
+
+static void onboard_hub_usbdev_disconnect(struct usb_device *udev)
+{
+	struct onboard_hub *hub = dev_get_drvdata(&udev->dev);
+
+	sysfs_remove_link(&udev->dev.kobj, "onboard_hub_dev");
+
+	onboard_hub_remove_usbdev(hub, udev);
+}
+
+static const struct usb_device_id onboard_hub_id_table[] = {
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.0 */
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.0 */
+	{},
+};
+
+MODULE_DEVICE_TABLE(usb, onboard_hub_id_table);
+
+static struct usb_device_driver onboard_hub_usbdev_driver = {
+
+	.name = "onboard-usb-hub",
+	.probe = onboard_hub_usbdev_probe,
+	.disconnect = onboard_hub_usbdev_disconnect,
+	.generic_subclass = 1,
+	.supports_autosuspend =	1,
+	.id_table = onboard_hub_id_table,
+};
+
+/************************** Driver (de)registration **************************/
+
+static int __init onboard_hub_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&onboard_hub_driver);
+	if (ret)
+		return ret;
+
+	ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE);
+	if (ret)
+		platform_driver_unregister(&onboard_hub_driver);
+
+	return ret;
+}
+module_init(onboard_hub_init);
+
+static void __exit onboard_hub_exit(void)
+{
+	usb_deregister_device_driver(&onboard_hub_usbdev_driver);
+	platform_driver_unregister(&onboard_hub_driver);
+}
+module_exit(onboard_hub_exit);
+
+MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
+MODULE_DESCRIPTION("Driver for discrete onboard USB hubs");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/usb/onboard_hub.h b/include/linux/usb/onboard_hub.h
new file mode 100644
index 000000000000..9be52dfae653
--- /dev/null
+++ b/include/linux/usb/onboard_hub.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_USB_ONBOARD_HUB_H
+#define __LINUX_USB_ONBOARD_HUB_H
+
+#ifdef CONFIG_USB_ONBOARD_HUB
+bool of_is_onboard_usb_hub(const struct device_node *np);
+#else
+static inline bool of_is_onboard_usb_hub(const struct device_node *np)
+{
+	return false;
+}
+#endif
+
+#endif /* __LINUX_USB_ONBOARD_HUB_H */
-- 
2.31.1.607.g51e8a6a459-goog


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [PATCH v10 3/5] of/platform: Add stubs for of_platform_device_create/destroy()
  2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 1/5] dt-bindings: usb: Add binding for Realtek RTS5411 hub controller Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
@ 2021-05-11 22:52 ` Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 4/5] usb: host: xhci-plat: Create platform device for onboard hubs in probe() Matthias Kaehlcke
                   ` (3 subsequent siblings)
  6 siblings, 0 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-11 22:52 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand
  Cc: Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Matthias Kaehlcke,
	Rob Herring

Code for platform_device_create() and of_platform_device_destroy() is
only generated if CONFIG_OF_ADDRESS=y. Add stubs to avoid unresolved
symbols when CONFIG_OF_ADDRESS is not set.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
---

Changes in v10:
- none

Changes in v9:
- added Rob's 'Acked-by' tag

Changes in v8:
- fixed C&P error in commit message

Changes in v7:
- none

Changes in v6:
- patch added to the series

 include/linux/of_platform.h | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index 84a966623e78..d15b6cd5e1c3 100644
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -61,16 +61,18 @@ static inline struct platform_device *of_find_device_by_node(struct device_node
 }
 #endif
 
+extern int of_platform_bus_probe(struct device_node *root,
+				 const struct of_device_id *matches,
+				 struct device *parent);
+
+#ifdef CONFIG_OF_ADDRESS
 /* Platform devices and busses creation */
 extern struct platform_device *of_platform_device_create(struct device_node *np,
 						   const char *bus_id,
 						   struct device *parent);
 
 extern int of_platform_device_destroy(struct device *dev, void *data);
-extern int of_platform_bus_probe(struct device_node *root,
-				 const struct of_device_id *matches,
-				 struct device *parent);
-#ifdef CONFIG_OF_ADDRESS
+
 extern int of_platform_populate(struct device_node *root,
 				const struct of_device_id *matches,
 				const struct of_dev_auxdata *lookup,
@@ -84,6 +86,18 @@ extern int devm_of_platform_populate(struct device *dev);
 
 extern void devm_of_platform_depopulate(struct device *dev);
 #else
+/* Platform devices and busses creation */
+static inline struct platform_device *of_platform_device_create(struct device_node *np,
+								const char *bus_id,
+								struct device *parent)
+{
+	return NULL;
+}
+static inline int of_platform_device_destroy(struct device *dev, void *data)
+{
+	return -ENODEV;
+}
+
 static inline int of_platform_populate(struct device_node *root,
 					const struct of_device_id *matches,
 					const struct of_dev_auxdata *lookup,
-- 
2.31.1.607.g51e8a6a459-goog


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [PATCH v10 4/5] usb: host: xhci-plat: Create platform device for onboard hubs in probe()
  2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (2 preceding siblings ...)
  2021-05-11 22:52 ` [PATCH v10 3/5] of/platform: Add stubs for of_platform_device_create/destroy() Matthias Kaehlcke
@ 2021-05-11 22:52 ` Matthias Kaehlcke
  2021-05-11 22:52 ` [PATCH v10 5/5] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub Matthias Kaehlcke
                   ` (2 subsequent siblings)
  6 siblings, 0 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-11 22:52 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand
  Cc: Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Matthias Kaehlcke,
	Al Cooper, Bjorn Andersson, Christian Lamparter, Colin Ian King,
	Dmitry Osipenko, Fabio Estevam, Masahiro Yamada, Mathias Nyman,
	Vinod Koul

Check during probe() if a hub supported by the onboard_usb_hub
driver is connected to the controller. If such a hub is found
create the corresponding platform device. This requires the
device tree to have a node for the hub with its vendor and
product id (which is not common for USB devices). Further the
platform device is only created when CONFIG_USB_ONBOARD_HUB=y/m.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---

Changes in v10:
- none

Changes in v9:
- added dependency on USB_ONBOARD_HUB (or !!USB_ONBOARD_HUB) to
  USB_XHCI_PLATFORM

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- patch added to the series

 drivers/usb/host/Kconfig     |  1 +
 drivers/usb/host/xhci-plat.c | 16 ++++++++++++++++
 include/linux/usb/hcd.h      |  2 ++
 3 files changed, 19 insertions(+)

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index b94f2a070c05..da50496787fe 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -54,6 +54,7 @@ config USB_XHCI_PCI_RENESAS
 config USB_XHCI_PLATFORM
 	tristate "Generic xHCI driver for a platform device"
 	select USB_XHCI_RCAR if ARCH_RENESAS
+	depends on USB_ONBOARD_HUB || !USB_ONBOARD_HUB
 	help
 	  Adds an xHCI host driver for a generic platform device, which
 	  provides a memory space and an irq.
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index c1edcc9b13ce..9c0fb7e8df1f 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -15,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/usb/onboard_hub.h>
 #include <linux/usb/phy.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
@@ -195,6 +196,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	int			ret;
 	int			irq;
 	struct xhci_plat_priv	*priv = NULL;
+	struct device_node	*np;
 
 
 	if (usb_disabled())
@@ -374,6 +376,17 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	 */
 	pm_runtime_forbid(&pdev->dev);
 
+	np = usb_of_get_device_node(hcd->self.root_hub, hcd->self.busnum);
+	if (np && of_is_onboard_usb_hub(np)) {
+		struct platform_device *pdev;
+
+		pdev = of_platform_device_create(np, NULL, NULL);
+		if (pdev)
+			hcd->onboard_hub_dev = &pdev->dev;
+		else
+			xhci_warn(xhci, "failed to create onboard hub platform device\n");
+	}
+
 	return 0;
 
 
@@ -420,6 +433,9 @@ static int xhci_plat_remove(struct platform_device *dev)
 	usb_remove_hcd(hcd);
 	usb_put_hcd(shared_hcd);
 
+	if (hcd->onboard_hub_dev)
+		of_platform_device_destroy(hcd->onboard_hub_dev, NULL);
+
 	clk_disable_unprepare(clk);
 	clk_disable_unprepare(reg_clk);
 	usb_put_hcd(hcd);
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 96281cd50ff6..d02a508e19b0 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -225,6 +225,8 @@ struct usb_hcd {
 	 * (ohci 32, uhci 1024, ehci 256/512/1024).
 	 */
 
+	struct device *onboard_hub_dev;
+
 	/* The HC driver's private data is stored at the end of
 	 * this structure.
 	 */
-- 
2.31.1.607.g51e8a6a459-goog


^ permalink raw reply	[flat|nested] 21+ messages in thread

* [PATCH v10 5/5] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
  2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (3 preceding siblings ...)
  2021-05-11 22:52 ` [PATCH v10 4/5] usb: host: xhci-plat: Create platform device for onboard hubs in probe() Matthias Kaehlcke
@ 2021-05-11 22:52 ` Matthias Kaehlcke
  2021-05-12  7:19 ` [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Alexander Dahl
  2021-05-21 12:30 ` Greg Kroah-Hartman
  6 siblings, 0 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-11 22:52 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand
  Cc: Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Matthias Kaehlcke,
	Andy Gross, Bjorn Andersson, linux-arm-msm

Add nodes for the onboard USB hub on trogdor devices. Remove the
'always-on' property from the hub regulator, since the regulator
is now managed by the onboard_usb_hub driver.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---

Changes in v10:
- keep 'regulator-boot-on' property
- updated commit message

Changes in v9:
- none

Changes in v8:
- none

Changes in v7:
- rebased on qcom/arm64-for-5.13 (with the rest of the series)

Changes in v6:
- added 'companion-hub' entry to both USB devices
- added 'vdd-supply' also to hub@2

Changes in v5:
- patch added to the series

 .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts | 19 ++++++++-----------
 .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts | 11 ++++-------
 .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts | 19 ++++++++-----------
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  | 19 ++++++++++++++++++-
 4 files changed, 38 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
index 5c997cd90069..bae85f6b2bfa 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r0.dts
@@ -23,17 +23,6 @@ &charger_thermal {
 	status = "disabled";
 };
 
-&pp3300_hub {
-	/* pp3300_l7c is used to power the USB hub */
-	/delete-property/regulator-always-on;
-	/delete-property/regulator-boot-on;
-};
-
-&pp3300_l7c {
-	regulator-always-on;
-	regulator-boot-on;
-};
-
 &sn65dsi86_out {
 	/*
 	 * Lane 0 was incorrectly mapped on the cable, but we've now decided
@@ -42,3 +31,11 @@ &sn65dsi86_out {
 	 */
 	lane-polarities = <1 0>;
 };
+
+&usb_hub_2_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
+
+&usb_hub_3_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts
index d9fbcc7bc5bd..45f014c3539d 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-lazor-r1.dts
@@ -23,13 +23,10 @@ &charger_thermal {
 	status = "disabled";
 };
 
-&pp3300_hub {
-	/* pp3300_l7c is used to power the USB hub */
-	/delete-property/regulator-always-on;
-	/delete-property/regulator-boot-on;
+&usb_hub_2_0 {
+	 vdd-supply = <&pp3300_l7c>;
 };
 
-&pp3300_l7c {
-	regulator-always-on;
-	regulator-boot-on;
+&usb_hub_3_0 {
+	 vdd-supply = <&pp3300_l7c>;
 };
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts b/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts
index 2b522f9e0d8f..2f5263e3d1b9 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-r1.dts
@@ -42,17 +42,6 @@ &panel {
 	compatible = "auo,b116xa01";
 };
 
-&pp3300_hub {
-	/* pp3300_l7c is used to power the USB hub */
-	/delete-property/regulator-always-on;
-	/delete-property/regulator-boot-on;
-};
-
-&pp3300_l7c {
-	regulator-always-on;
-	regulator-boot-on;
-};
-
 &sdhc_2 {
 	status = "okay";
 };
@@ -61,6 +50,14 @@ &trackpad {
 	interrupts = <58 IRQ_TYPE_EDGE_FALLING>;
 };
 
+&usb_hub_2_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
+
+&usb_hub_3_0 {
+	 vdd-supply = <&pp3300_l7c>;
+};
+
 /* PINCTRL - modifications to sc7180-trogdor.dtsi */
 
 &trackpad_int_1v8_odl {
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
index 192e2e424fde..0d6a7447dc77 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
@@ -206,7 +206,6 @@ pp3300_hub: pp3300-hub {
 		pinctrl-names = "default";
 		pinctrl-0 = <&en_pp3300_hub>;
 
-		regulator-always-on;
 		regulator-boot-on;
 
 		vin-supply = <&pp3300_a>;
@@ -848,6 +847,24 @@ &usb_1 {
 
 &usb_1_dwc3 {
 	dr_mode = "host";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	/* 2.0 hub on port 1 */
+	usb_hub_2_0: hub@1 {
+		compatible = "usbbda,5411";
+		reg = <1>;
+		vdd-supply = <&pp3300_hub>;
+		companion-hub = <&usb_hub_3_0>;
+	};
+
+	/* 3.0 hub on port 2 */
+	usb_hub_3_0: hub@2 {
+		compatible = "usbbda,411";
+		reg = <2>;
+		vdd-supply = <&pp3300_hub>;
+		companion-hub = <&usb_hub_2_0>;
+	};
 };
 
 &usb_1_hsphy {
-- 
2.31.1.607.g51e8a6a459-goog


^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver
  2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (4 preceding siblings ...)
  2021-05-11 22:52 ` [PATCH v10 5/5] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub Matthias Kaehlcke
@ 2021-05-12  7:19 ` Alexander Dahl
  2021-05-12 16:37   ` Matthias Kaehlcke
  2021-05-21 12:30 ` Greg Kroah-Hartman
  6 siblings, 1 reply; 21+ messages in thread
From: Alexander Dahl @ 2021-05-12  7:19 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Andy Gross, Bjorn Andersson,
	Christian Lamparter, Colin Ian King, Dmitry Osipenko,
	Fabio Estevam, Masahiro Yamada, Mathias Nyman, Vinod Koul,
	linux-arm-msm

Hello Matthias,

just a curious informal question, see below.

Am Tue, May 11, 2021 at 03:52:18PM -0700 schrieb Matthias Kaehlcke:
> This series adds:
> - the onboard_usb_hub_driver
> - glue in the xhci-plat driver to create the onboard_usb_hub
>   platform device if needed
> - a device tree binding for the Realtek RTS5411 USB hub controller
> - device tree changes that add RTS5411 entries for the QCA SC7180
>   based boards trogdor and lazor
> - a couple of stubs for platform device functions to avoid
>   unresolved symbols with certain kernel configs
> 
> The main issue the driver addresses is that a USB hub needs to be
> powered before it can be discovered. For discrete onboard hubs (an
> example for such a hub is the Realtek RTS5411) this is often solved
> by supplying the hub with an 'always-on' regulator, which is kind
> of a hack. Some onboard hubs may require further initialization
> steps, like changing the state of a GPIO or enabling a clock, which
> requires even more hacks. This driver creates a platform device
> representing the hub which performs the necessary initialization.
> Currently it only supports switching on a single regulator, support
> for multiple regulators or other actions can be added as needed.
> Different initialization sequences can be supported based on the
> compatible string.

This sounds like it would be useful for other hub controllers as well?
For example, would the Microchip USB3503 (former SMSC,
drivers/usb/misc/usb3503.c, [1]) fall into this category? That chip is
used on the "Cubietech Cubietruck Plus" for example.

> Besides performing the initialization the driver can be configured
> to power the hub off during system suspend. This can help to extend
> battery life on battery powered devices which have no requirements
> to keep the hub powered during suspend. The driver can also be
> configured to leave the hub powered when a wakeup capable USB device
> is connected when suspending, and power it off otherwise.

Sounds interesting.

Greets
Alex

[1] https://www.microchip.com/wwwproducts/en/USB3503

> Changes in v10:
> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
> - keep 'regulator-boot-on' property for pp3300_hub
> 
> Changes in v9:
> - added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
>   USB_PLATFORM_XHCI
> 
> Changes in v7:
> - updated DT binding
> - series rebased on qcom/arm64-for-5.13
> 
> Changes in v6:
> - updated summary
> 
> Changes in v5:
> - cover letter added
> 
> Matthias Kaehlcke (5):
>   dt-bindings: usb: Add binding for Realtek RTS5411 hub controller
>   USB: misc: Add onboard_usb_hub driver
>   of/platform: Add stubs for of_platform_device_create/destroy()
>   usb: host: xhci-plat: Create platform device for onboard hubs in
>     probe()
>   arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub
> 
>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
>  .../bindings/usb/realtek,rts5411.yaml         |  62 +++
>  MAINTAINERS                                   |   7 +
>  .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
>  .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  11 +-
>  .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
>  drivers/usb/host/Kconfig                      |   1 +
>  drivers/usb/host/xhci-plat.c                  |  16 +
>  drivers/usb/misc/Kconfig                      |  17 +
>  drivers/usb/misc/Makefile                     |   1 +
>  drivers/usb/misc/onboard_usb_hub.c            | 415 ++++++++++++++++++
>  include/linux/of_platform.h                   |  22 +-
>  include/linux/usb/hcd.h                       |   2 +
>  include/linux/usb/onboard_hub.h               |  15 +
>  15 files changed, 600 insertions(+), 34 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
>  create mode 100644 Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
>  create mode 100644 drivers/usb/misc/onboard_usb_hub.c
>  create mode 100644 include/linux/usb/onboard_hub.h
> 
> -- 
> 2.31.1.607.g51e8a6a459-goog
> 

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver
  2021-05-12  7:19 ` [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Alexander Dahl
@ 2021-05-12 16:37   ` Matthias Kaehlcke
  0 siblings, 0 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-12 16:37 UTC (permalink / raw)
  To: Alexander Dahl
  Cc: Greg Kroah-Hartman, Alan Stern, Rob Herring, Frank Rowand,
	Michal Simek, devicetree, Douglas Anderson, linux-usb,
	Peter Chen, linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Andy Gross, Bjorn Andersson,
	Christian Lamparter, Colin Ian King, Dmitry Osipenko,
	Fabio Estevam, Masahiro Yamada, Mathias Nyman, Vinod Koul,
	linux-arm-msm

Hi Alexander,

On Wed, May 12, 2021 at 09:19:54AM +0200, Alexander Dahl wrote:
> Hello Matthias,
> 
> just a curious informal question, see below.
> 
> Am Tue, May 11, 2021 at 03:52:18PM -0700 schrieb Matthias Kaehlcke:
> > This series adds:
> > - the onboard_usb_hub_driver
> > - glue in the xhci-plat driver to create the onboard_usb_hub
> >   platform device if needed
> > - a device tree binding for the Realtek RTS5411 USB hub controller
> > - device tree changes that add RTS5411 entries for the QCA SC7180
> >   based boards trogdor and lazor
> > - a couple of stubs for platform device functions to avoid
> >   unresolved symbols with certain kernel configs
> > 
> > The main issue the driver addresses is that a USB hub needs to be
> > powered before it can be discovered. For discrete onboard hubs (an
> > example for such a hub is the Realtek RTS5411) this is often solved
> > by supplying the hub with an 'always-on' regulator, which is kind
> > of a hack. Some onboard hubs may require further initialization
> > steps, like changing the state of a GPIO or enabling a clock, which
> > requires even more hacks. This driver creates a platform device
> > representing the hub which performs the necessary initialization.
> > Currently it only supports switching on a single regulator, support
> > for multiple regulators or other actions can be added as needed.
> > Different initialization sequences can be supported based on the
> > compatible string.
> 
> This sounds like it would be useful for other hub controllers as well?
> For example, would the Microchip USB3503 (former SMSC,
> drivers/usb/misc/usb3503.c, [1]) fall into this category? That chip is
> used on the "Cubietech Cubietruck Plus" for example.

usb3503.c provides two 'separate' USB3503 drivers (which share some
code), a i2c client driver and a platform driver. IIUC on a system with
an USB3503 only one of these drivers is used. Theoretically it should be
feasible to extend the onboard_usb_hub driver to cover the functionality
of the platform driver in usb3503.c (essentially to control GPIOs and
clocks at initialization time and suspend/resume). Another question is
whether that would be desirable, since the i2c and the platform driver
share code, which then would be duplicated in the i2c and onboard_usb_hub
driver, unless a way is found to keep sharing that code.

The i2c driver can't be completely replaced by the onboard_usb_hub
driver, due to the i2c communications. It might be possible to have the
i2c driver and the onboard_usb_hub collaborate, however I expect it
would take a certain effort to design and implement a solid solution.

Thanks

Matthias

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-11 22:52 ` [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
@ 2021-05-18 17:05   ` Matthias Kaehlcke
  2021-05-18 19:45     ` Alan Stern
  0 siblings, 1 reply; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-18 17:05 UTC (permalink / raw)
  To: Alan Stern
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

Hi Alan,

You seemed to have a generally favorable view of this driver,
but I haven't heard from you in a while :)

On v4 expressed a series of suggestions and concerns, which
should be addressed in this version:

https://lore.kernel.org/patchwork/patch/1313000/
https://lore.kernel.org/patchwork/patch/1313001/

Rob acked the DT binding and the of_platform change. Please let me
know if the USB part needs any further changes or if you think this
series is ready to land.

Thanks

Matthias

On Tue, May 11, 2021 at 03:52:20PM -0700, Matthias Kaehlcke wrote:
> The main issue this driver addresses is that a USB hub needs to be
> powered before it can be discovered. For discrete onboard hubs (an
> example for such a hub is the Realtek RTS5411) this is often solved
> by supplying the hub with an 'always-on' regulator, which is kind
> of a hack. Some onboard hubs may require further initialization
> steps, like changing the state of a GPIO or enabling a clock, which
> requires even more hacks. This driver creates a platform device
> representing the hub which performs the necessary initialization.
> Currently it only supports switching on a single regulator, support
> for multiple regulators or other actions can be added as needed.
> Different initialization sequences can be supported based on the
> compatible string.
> 
> Besides performing the initialization the driver can be configured
> to power the hub off during system suspend. This can help to extend
> battery life on battery powered devices which have no requirements
> to keep the hub powered during suspend. The driver can also be
> configured to leave the hub powered when a wakeup capable USB device
> is connected when suspending, and power it off otherwise.
> 
> Technically the driver consists of two drivers, the platform driver
> described above and a very thin USB driver that subclasses the
> generic driver. The purpose of this driver is to provide the platform
> driver with the USB devices corresponding to the hub(s) (a hub
> controller may provide multiple 'logical' hubs, e.g. one to support
> USB 2.0 and another for USB 3.x).
> 
> Note: the driver currently only works with hubs connected directly
> to a root hub, but it could be extended to support other
> configurations if needed.
> 
> Co-developed-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
> Signed-off-by: Ravi Chandra Sadineni <ravisadineni@chromium.org>
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
> 
> Changes in v10:
> - always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
> 
> Changes in v9:
> - none
> 
> Changes in v8:
> - none
> 
> Changes in v7:
> - don't declare stub for of_is_onboard_usb_hub() when
>   CONFIG_COMPILE_TEST is defined
> 
> Changes in v6:
> - use 'companion-hub' to locate the platform device, instead of
>   scanning through the nodes of the parent
> - added ABI documentation for 'always_powered_in_suspend'
> - sysfs_emit() instead of sprintf() in always_powered_in_suspend_show()
> - register sysfs attribute through driver.dev_groups
> - evaluate return value of driver_attach() in _probe()
> - use dev_warn() instead of WARN_ON() in _probe()
> - include 'onboard_hub.h'
> 
> Changes in v5:
> - the platform device is now instantiated from the same DT node
>   as the 'primary' USB hub device
>   - use the USB compatible strings for the platform device
>   - refactored _find_onboard_hub() to search the parents child
>     nodes for a platform device with a matching compatible string
>   - added exported function of_is_onboard_usb_hub() to allow other
>     drivers (like xhci_plat) to check if one of their child DT nodes
>     is a supported hub
> - use late suspend to make sure info about wakeup enabled descendants
>   is updated
> - call driver_attach() for the USB driver in onboard_hub_probe() to
>   make sure the driver is re-attached after the device_release_driver()
>   calls in onboard_hub_remove()
> - renamed sysfs attribute 'power_off_in_suspend' to
>   'always_powered_in_suspend'
> - added sysfs symlinks between platform device and USB devices
> - marked 'onboard_hub_pm_ops' as __maybe_unused
> - removed 'realtek' compatible string which is not needed at this
>   point
> - fix log for regulator_disable() failure
> 
> Changes in v4:
> - updated Kconfig documentation
> - changed the loop in onboard_hub_remove() to release the hub lock
>   before unbinding the USB device and make self deadlock prevention
>   less clunky
> - fixed return value in onboard_hub_usbdev_probe()
> - added entry to MAINTAINERS file
> 
> Changes in v3:
> - updated the commit message
> - updated description in Kconfig
> - remove include of 'core/usb.h'
> - use 'is_powered_on' flag instead of 'has_wakeup_capable_descendants'
> - added 'going_away' flag to struct onboard_hub
>   - don't allow adding new USB devices when the platform device is going away
>   - don't bother with deleting the list item in onboard_hub_remove_usbdev()
>     when the platform device is going away
> - don't assume in onboard_hub_suspend() that all USB hub devices are
>   connected to the same controller
> - removed unnecessary devm_kfree() from onboard_hub_remove_usbdev()
> - fixed error handling in onboard_hub_remove_usbdev()
> - use kstrtobool() instead of strtobool() in power_off_in_suspend_store()
> - unbind USB devices in onboard_hub_remove() to avoid dangling references
>   to the platform device
> - moved put_device() for platform device to _find_onboard_hub()
> - changed return value of onboard_hub_remove_usbdev() to void
> - evaluate return value of onboard_hub_add_usbdev()
> - register 'power_off_in_suspend' as managed device attribute
> - use USB_DEVICE macro instead manual initialization
> - add unwinding to onboard_hub_init()
> - updated MODULE_DESCRIPTION
> - use module_init() instead of device_initcall()
> 
> Changes in v2:
> - check wakeup enabled state of the USB controller instead of
>   using 'wakeup-source' property
> - use sysfs attribute instead of DT property to determine if
>   the hub should be powered off at all during system suspend
> - added missing brace in onboard_hub_suspend()
> - updated commit message
> - use pm_ptr for pm_ops as suggested by Alan
> 
> Changes in v1:
> - renamed the driver to 'onboard_usb_hub'
> - single file for platform and USB driver
> - USB hub devices register with the platform device
>   - the DT includes a phandle of the platform device
> - the platform device now controls when power is turned off
> - the USB driver became a very thin subclass of the generic USB
>   driver
> - enabled autosuspend support
> 
>  .../sysfs-bus-platform-onboard-usb-hub        |   8 +
>  MAINTAINERS                                   |   7 +
>  drivers/usb/misc/Kconfig                      |  17 +
>  drivers/usb/misc/Makefile                     |   1 +
>  drivers/usb/misc/onboard_usb_hub.c            | 415 ++++++++++++++++++
>  include/linux/usb/onboard_hub.h               |  15 +
>  6 files changed, 463 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
>  create mode 100644 drivers/usb/misc/onboard_usb_hub.c
>  create mode 100644 include/linux/usb/onboard_hub.h
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub b/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
> new file mode 100644
> index 000000000000..e981d83648e6
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
> @@ -0,0 +1,8 @@
> +What:		/sys/bus/platform/devices/<dev>/always_powered_in_suspend
> +Date:		March 2021
> +KernelVersion:	5.13
> +Contact:	Matthias Kaehlcke <matthias@kaehlcke.net>
> +		linux-usb@vger.kernel.org
> +Description:
> +		(RW) Controls whether the USB hub remains always powered
> +		during system suspend or not.
> \ No newline at end of file
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d92f85ca831d..882ae6e378c5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13297,6 +13297,13 @@ S:	Maintained
>  T:	git git://linuxtv.org/media_tree.git
>  F:	drivers/media/i2c/ov9734.c
>  
> +ONBOARD USB HUB DRIVER
> +M:	Matthias Kaehlcke <mka@chromium.org>
> +L:	linux-usb@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/usb/onboard_usb_hub.yaml
> +F:	drivers/usb/misc/onboard_usb_hub.c
> +
>  ONENAND FLASH DRIVER
>  M:	Kyungmin Park <kyungmin.park@samsung.com>
>  L:	linux-mtd@lists.infradead.org
> diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
> index 8f1144359012..f534269fbb20 100644
> --- a/drivers/usb/misc/Kconfig
> +++ b/drivers/usb/misc/Kconfig
> @@ -284,3 +284,20 @@ config BRCM_USB_PINMAP
>  	  This option enables support for remapping some USB external
>  	  signals, which are typically on dedicated pins on the chip,
>  	  to any gpio.
> +
> +config USB_ONBOARD_HUB
> +	tristate "Onboard USB hub support"
> +	depends on OF || COMPILE_TEST
> +	help
> +	  Say Y here if you want to support discrete onboard USB hubs that
> +	  don't require an additional control bus for initialization, but
> +	  need some nontrivial form of initialization, such as enabling a
> +	  power regulator. An example for such a hub is the Realtek
> +	  RTS5411.
> +
> +	  The driver can be configured to turn off the power of the hub
> +	  during system suspend. This may reduce power consumption while
> +	  the system is suspended.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called onboard_usb_hub.
> diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
> index 5f4e598573ab..2c5aec6f1b26 100644
> --- a/drivers/usb/misc/Makefile
> +++ b/drivers/usb/misc/Makefile
> @@ -32,3 +32,4 @@ obj-$(CONFIG_USB_CHAOSKEY)		+= chaoskey.o
>  obj-$(CONFIG_USB_SISUSBVGA)		+= sisusbvga/
>  obj-$(CONFIG_USB_LINK_LAYER_TEST)	+= lvstest.o
>  obj-$(CONFIG_BRCM_USB_PINMAP)		+= brcmstb-usb-pinmap.o
> +obj-$(CONFIG_USB_ONBOARD_HUB)		+= onboard_usb_hub.o
> diff --git a/drivers/usb/misc/onboard_usb_hub.c b/drivers/usb/misc/onboard_usb_hub.c
> new file mode 100644
> index 000000000000..db926699a5ec
> --- /dev/null
> +++ b/drivers/usb/misc/onboard_usb_hub.c
> @@ -0,0 +1,415 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + *  Driver for onboard USB hubs
> + *
> + * Copyright (c) 2020, Google LLC
> + */
> +
> +#include <linux/device.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/suspend.h>
> +#include <linux/sysfs.h>
> +#include <linux/usb.h>
> +#include <linux/usb/hcd.h>
> +#include <linux/usb/onboard_hub.h>
> +
> +static struct usb_device_driver onboard_hub_usbdev_driver;
> +
> +/************************** Platform driver **************************/
> +
> +struct udev_node {
> +	struct usb_device *udev;
> +	struct list_head list;
> +};
> +
> +struct onboard_hub {
> +	struct regulator *vdd;
> +	struct device *dev;
> +	bool always_powered_in_suspend;
> +	bool is_powered_on;
> +	bool going_away;
> +	struct list_head udev_list;
> +	struct mutex lock;
> +};
> +
> +static int onboard_hub_power_on(struct onboard_hub *hub)
> +{
> +	int err;
> +
> +	err = regulator_enable(hub->vdd);
> +	if (err) {
> +		dev_err(hub->dev, "failed to enable regulator: %d\n", err);
> +		return err;
> +	}
> +
> +	hub->is_powered_on = true;
> +
> +	return 0;
> +}
> +
> +static int onboard_hub_power_off(struct onboard_hub *hub)
> +{
> +	int err;
> +
> +	err = regulator_disable(hub->vdd);
> +	if (err) {
> +		dev_err(hub->dev, "failed to disable regulator: %d\n", err);
> +		return err;
> +	}
> +
> +	hub->is_powered_on = false;
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused onboard_hub_suspend(struct device *dev)
> +{
> +	struct onboard_hub *hub = dev_get_drvdata(dev);
> +	struct udev_node *node;
> +	bool power_off;
> +	int rc = 0;
> +
> +	if (hub->always_powered_in_suspend)
> +		return 0;
> +
> +	power_off = true;
> +
> +	mutex_lock(&hub->lock);
> +
> +	list_for_each_entry(node, &hub->udev_list, list) {
> +		if (!device_may_wakeup(node->udev->bus->controller))
> +			continue;
> +
> +		if (usb_wakeup_enabled_descendants(node->udev)) {
> +			power_off = false;
> +			break;
> +		}
> +	}
> +
> +	mutex_unlock(&hub->lock);
> +
> +	if (power_off)
> +		rc = onboard_hub_power_off(hub);
> +
> +	return rc;
> +}
> +
> +static int __maybe_unused onboard_hub_resume(struct device *dev)
> +{
> +	struct onboard_hub *hub = dev_get_drvdata(dev);
> +	int rc = 0;
> +
> +	if (!hub->is_powered_on)
> +		rc = onboard_hub_power_on(hub);
> +
> +	return rc;
> +}
> +
> +static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev)
> +{
> +	struct udev_node *node;
> +	char link_name[64];
> +	int ret = 0;
> +
> +	mutex_lock(&hub->lock);
> +
> +	if (hub->going_away) {
> +		ret = -EINVAL;
> +		goto unlock;
> +	}
> +
> +	node = devm_kzalloc(hub->dev, sizeof(*node), GFP_KERNEL);
> +	if (!node) {
> +		ret = -ENOMEM;
> +		goto unlock;
> +	}
> +
> +	node->udev = udev;
> +
> +	list_add(&node->list, &hub->udev_list);
> +
> +	snprintf(link_name, sizeof(link_name), "usb_dev.%s", dev_name(&udev->dev));
> +	WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name));
> +
> +unlock:
> +	mutex_unlock(&hub->lock);
> +
> +	return ret;
> +}
> +
> +static void onboard_hub_remove_usbdev(struct onboard_hub *hub, struct usb_device *udev)
> +{
> +	struct udev_node *node;
> +	char link_name[64];
> +
> +	snprintf(link_name, sizeof(link_name), "usb_dev.%s", dev_name(&udev->dev));
> +	sysfs_remove_link(&hub->dev->kobj, link_name);
> +
> +	mutex_lock(&hub->lock);
> +
> +	list_for_each_entry(node, &hub->udev_list, list) {
> +		if (node->udev == udev) {
> +			list_del(&node->list);
> +			break;
> +		}
> +	}
> +
> +	mutex_unlock(&hub->lock);
> +}
> +
> +static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr,
> +			   char *buf)
> +{
> +	struct onboard_hub *hub = dev_get_drvdata(dev);
> +
> +	return sysfs_emit(buf, "%d\n", hub->always_powered_in_suspend);
> +}
> +
> +static ssize_t always_powered_in_suspend_store(struct device *dev, struct device_attribute *attr,
> +			    const char *buf, size_t count)
> +{
> +	struct onboard_hub *hub = dev_get_drvdata(dev);
> +	bool val;
> +	int ret;
> +
> +	ret = kstrtobool(buf, &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	hub->always_powered_in_suspend = val;
> +
> +	return count;
> +}
> +static DEVICE_ATTR_RW(always_powered_in_suspend);
> +
> +static struct attribute *onboard_hub_attrs[] = {
> +	&dev_attr_always_powered_in_suspend.attr,
> +	NULL,
> +};
> +ATTRIBUTE_GROUPS(onboard_hub);
> +
> +static int onboard_hub_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct onboard_hub *hub;
> +	int err;
> +
> +	hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL);
> +	if (!hub)
> +		return -ENOMEM;
> +
> +	hub->vdd = devm_regulator_get(dev, "vdd");
> +	if (IS_ERR(hub->vdd))
> +		return PTR_ERR(hub->vdd);
> +
> +	hub->dev = dev;
> +	mutex_init(&hub->lock);
> +	INIT_LIST_HEAD(&hub->udev_list);
> +
> +	dev_set_drvdata(dev, hub);
> +
> +	err = onboard_hub_power_on(hub);
> +	if (err)
> +		return err;
> +
> +	/*
> +	 * The USB driver might have been detached from the USB devices by
> +	 * onboard_hub_remove(), make sure to re-attach it if needed.
> +	 */
> +	err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver);
> +	if (err) {
> +		onboard_hub_power_off(hub);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int onboard_hub_remove(struct platform_device *pdev)
> +{
> +	struct onboard_hub *hub = dev_get_drvdata(&pdev->dev);
> +	struct udev_node *node;
> +	struct usb_device *udev;
> +
> +	hub->going_away = true;
> +
> +	mutex_lock(&hub->lock);
> +
> +	/* unbind the USB devices to avoid dangling references to this device */
> +	while (!list_empty(&hub->udev_list)) {
> +		node = list_first_entry(&hub->udev_list, struct udev_node, list);
> +		udev = node->udev;
> +
> +		/*
> +		 * Unbinding the driver will call onboard_hub_remove_usbdev(),
> +		 * which acquires hub->lock.  We must release the lock first.
> +		 */
> +		get_device(&udev->dev);
> +		mutex_unlock(&hub->lock);
> +		device_release_driver(&udev->dev);
> +		put_device(&udev->dev);
> +		mutex_lock(&hub->lock);
> +	}
> +
> +	mutex_unlock(&hub->lock);
> +
> +	return onboard_hub_power_off(hub);
> +}
> +
> +static const struct of_device_id onboard_hub_match[] = {
> +	{ .compatible = "usbbda,411" },
> +	{ .compatible = "usbbda,5411" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, onboard_hub_match);
> +
> +bool of_is_onboard_usb_hub(const struct device_node *np)
> +{
> +	return !!of_match_node(onboard_hub_match, np);
> +}
> +EXPORT_SYMBOL_GPL(of_is_onboard_usb_hub);
> +
> +static const struct dev_pm_ops __maybe_unused onboard_hub_pm_ops = {
> +	SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_hub_suspend, onboard_hub_resume)
> +};
> +
> +static struct platform_driver onboard_hub_driver = {
> +	.probe = onboard_hub_probe,
> +	.remove = onboard_hub_remove,
> +
> +	.driver = {
> +		.name = "onboard-usb-hub",
> +		.of_match_table = onboard_hub_match,
> +		.pm = pm_ptr(&onboard_hub_pm_ops),
> +		.dev_groups = onboard_hub_groups,
> +	},
> +};
> +
> +/************************** USB driver **************************/
> +
> +#define VENDOR_ID_REALTEK	0x0bda
> +
> +/*
> + * Returns the onboard_hub platform device that is associated with the USB
> + * device passed as parameter.
> + */
> +static struct onboard_hub *_find_onboard_hub(struct device *dev)
> +{
> +	struct platform_device *pdev;
> +	struct device_node *np;
> +	phandle ph;
> +
> +	pdev = of_find_device_by_node(dev->of_node);
> +	if (!pdev) {
> +		if (of_property_read_u32(dev->of_node, "companion-hub", &ph)) {
> +			dev_err(dev, "failed to read 'companion-hub' property\n");
> +			return ERR_PTR(-EINVAL);
> +		}
> +
> +		np = of_find_node_by_phandle(ph);
> +		if (!np) {
> +			dev_err(dev, "failed to find device node for companion hub\n");
> +			return ERR_PTR(-EINVAL);
> +		}
> +
> +		pdev = of_find_device_by_node(np);
> +		of_node_put(np);
> +
> +		if (!pdev)
> +			return ERR_PTR(-EPROBE_DEFER);
> +	}
> +
> +	put_device(&pdev->dev);
> +
> +	return dev_get_drvdata(&pdev->dev);
> +}
> +
> +static int onboard_hub_usbdev_probe(struct usb_device *udev)
> +{
> +	struct device *dev = &udev->dev;
> +	struct onboard_hub *hub;
> +	int err;
> +
> +	/* ignore supported hubs without device tree node */
> +	if (!dev->of_node)
> +		return -ENODEV;
> +
> +	hub = _find_onboard_hub(dev);
> +	if (IS_ERR(hub))
> +		return PTR_ERR(hub);
> +
> +	dev_set_drvdata(dev, hub);
> +
> +	err = onboard_hub_add_usbdev(hub, udev);
> +	if (err)
> +		return err;
> +
> +	err = sysfs_create_link(&udev->dev.kobj, &hub->dev->kobj, "onboard_hub_dev");
> +	if (err)
> +		dev_warn(&udev->dev, "failed to create symlink to platform device: %d\n", err);
> +
> +	return 0;
> +}
> +
> +static void onboard_hub_usbdev_disconnect(struct usb_device *udev)
> +{
> +	struct onboard_hub *hub = dev_get_drvdata(&udev->dev);
> +
> +	sysfs_remove_link(&udev->dev.kobj, "onboard_hub_dev");
> +
> +	onboard_hub_remove_usbdev(hub, udev);
> +}
> +
> +static const struct usb_device_id onboard_hub_id_table[] = {
> +	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.0 */
> +	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.0 */
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(usb, onboard_hub_id_table);
> +
> +static struct usb_device_driver onboard_hub_usbdev_driver = {
> +
> +	.name = "onboard-usb-hub",
> +	.probe = onboard_hub_usbdev_probe,
> +	.disconnect = onboard_hub_usbdev_disconnect,
> +	.generic_subclass = 1,
> +	.supports_autosuspend =	1,
> +	.id_table = onboard_hub_id_table,
> +};
> +
> +/************************** Driver (de)registration **************************/
> +
> +static int __init onboard_hub_init(void)
> +{
> +	int ret;
> +
> +	ret = platform_driver_register(&onboard_hub_driver);
> +	if (ret)
> +		return ret;
> +
> +	ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE);
> +	if (ret)
> +		platform_driver_unregister(&onboard_hub_driver);
> +
> +	return ret;
> +}
> +module_init(onboard_hub_init);
> +
> +static void __exit onboard_hub_exit(void)
> +{
> +	usb_deregister_device_driver(&onboard_hub_usbdev_driver);
> +	platform_driver_unregister(&onboard_hub_driver);
> +}
> +module_exit(onboard_hub_exit);
> +
> +MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
> +MODULE_DESCRIPTION("Driver for discrete onboard USB hubs");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/usb/onboard_hub.h b/include/linux/usb/onboard_hub.h
> new file mode 100644
> index 000000000000..9be52dfae653
> --- /dev/null
> +++ b/include/linux/usb/onboard_hub.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef __LINUX_USB_ONBOARD_HUB_H
> +#define __LINUX_USB_ONBOARD_HUB_H
> +
> +#ifdef CONFIG_USB_ONBOARD_HUB
> +bool of_is_onboard_usb_hub(const struct device_node *np);
> +#else
> +static inline bool of_is_onboard_usb_hub(const struct device_node *np)
> +{
> +	return false;
> +}
> +#endif
> +
> +#endif /* __LINUX_USB_ONBOARD_HUB_H */
> -- 
> 2.31.1.607.g51e8a6a459-goog
> 

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-18 17:05   ` Matthias Kaehlcke
@ 2021-05-18 19:45     ` Alan Stern
  2021-05-18 21:40       ` Matthias Kaehlcke
  0 siblings, 1 reply; 21+ messages in thread
From: Alan Stern @ 2021-05-18 19:45 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Tue, May 18, 2021 at 10:05:49AM -0700, Matthias Kaehlcke wrote:
> Hi Alan,
> 
> You seemed to have a generally favorable view of this driver,
> but I haven't heard from you in a while :)
> 
> On v4 expressed a series of suggestions and concerns, which
> should be addressed in this version:
> 
> https://lore.kernel.org/patchwork/patch/1313000/
> https://lore.kernel.org/patchwork/patch/1313001/
> 
> Rob acked the DT binding and the of_platform change. Please let me
> know if the USB part needs any further changes or if you think this
> series is ready to land.

Those were long and complicated threads, and a lot of the material has
gone out of my brain since last October.  :-(

Still, at the time when this was first posted I don't remember there
being any big outstanding issues regarding the USB part of the
implementation.  It seemed to be pretty much all in order.

You can add:

Acked-by: Alan Stern <stern@rowland.harvard.edu>

to this patch.  Greg KH may have some thoughts of his own...

Alan Stern

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-18 19:45     ` Alan Stern
@ 2021-05-18 21:40       ` Matthias Kaehlcke
  2021-05-19  5:06         ` Greg Kroah-Hartman
  2021-05-19 14:43         ` Alan Stern
  0 siblings, 2 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-18 21:40 UTC (permalink / raw)
  To: Alan Stern, Greg Kroah-Hartman
  Cc: Rob Herring, Frank Rowand, Michal Simek, devicetree,
	Douglas Anderson, linux-usb, Peter Chen, linux-kernel,
	Stephen Boyd, Ravi Chandra Sadineni, Krzysztof Kozlowski,
	Bastien Nocera, Al Cooper, Alexander A. Klimov, Masahiro Yamada

On Tue, May 18, 2021 at 03:45:11PM -0400, Alan Stern wrote:
> On Tue, May 18, 2021 at 10:05:49AM -0700, Matthias Kaehlcke wrote:
> > Hi Alan,
> > 
> > You seemed to have a generally favorable view of this driver,
> > but I haven't heard from you in a while :)
> > 
> > On v4 expressed a series of suggestions and concerns, which
> > should be addressed in this version:
> > 
> > https://lore.kernel.org/patchwork/patch/1313000/
> > https://lore.kernel.org/patchwork/patch/1313001/
> > 
> > Rob acked the DT binding and the of_platform change. Please let me
> > know if the USB part needs any further changes or if you think this
> > series is ready to land.
> 
> Those were long and complicated threads, and a lot of the material has
> gone out of my brain since last October.  :-(
> 
> Still, at the time when this was first posted I don't remember there
> being any big outstanding issues regarding the USB part of the
> implementation.  It seemed to be pretty much all in order.
> 
> You can add:
> 
> Acked-by: Alan Stern <stern@rowland.harvard.edu>
> 
> to this patch.  Greg KH may have some thoughts of his own...

Thanks!

Could you also have a look at "[4/5] usb: host: xhci-plat:
Create platform device for onboard hubs in probe()"
(https://lore.kernel.org/patchwork/patch/1425453/)? It's a
relatively short patch that creates the platform device for
the driver from xhci-plat as you suggested in the v4
discussion.

Greg, are there any more concerns from your side?

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-18 21:40       ` Matthias Kaehlcke
@ 2021-05-19  5:06         ` Greg Kroah-Hartman
  2021-05-19 14:43         ` Alan Stern
  1 sibling, 0 replies; 21+ messages in thread
From: Greg Kroah-Hartman @ 2021-05-19  5:06 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Alan Stern, Rob Herring, Frank Rowand, Michal Simek, devicetree,
	Douglas Anderson, linux-usb, Peter Chen, linux-kernel,
	Stephen Boyd, Ravi Chandra Sadineni, Krzysztof Kozlowski,
	Bastien Nocera, Al Cooper, Alexander A. Klimov, Masahiro Yamada

On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> On Tue, May 18, 2021 at 03:45:11PM -0400, Alan Stern wrote:
> > On Tue, May 18, 2021 at 10:05:49AM -0700, Matthias Kaehlcke wrote:
> > > Hi Alan,
> > > 
> > > You seemed to have a generally favorable view of this driver,
> > > but I haven't heard from you in a while :)
> > > 
> > > On v4 expressed a series of suggestions and concerns, which
> > > should be addressed in this version:
> > > 
> > > https://lore.kernel.org/patchwork/patch/1313000/
> > > https://lore.kernel.org/patchwork/patch/1313001/
> > > 
> > > Rob acked the DT binding and the of_platform change. Please let me
> > > know if the USB part needs any further changes or if you think this
> > > series is ready to land.
> > 
> > Those were long and complicated threads, and a lot of the material has
> > gone out of my brain since last October.  :-(
> > 
> > Still, at the time when this was first posted I don't remember there
> > being any big outstanding issues regarding the USB part of the
> > implementation.  It seemed to be pretty much all in order.
> > 
> > You can add:
> > 
> > Acked-by: Alan Stern <stern@rowland.harvard.edu>
> > 
> > to this patch.  Greg KH may have some thoughts of his own...
> 
> Thanks!
> 
> Could you also have a look at "[4/5] usb: host: xhci-plat:
> Create platform device for onboard hubs in probe()"
> (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> relatively short patch that creates the platform device for
> the driver from xhci-plat as you suggested in the v4
> discussion.
> 
> Greg, are there any more concerns from your side?

Yes, I think there are, but like Alan said, it's been a long time since
I've looked at this.  I'll review it soon when I get a chance...

greg k-h

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-18 21:40       ` Matthias Kaehlcke
  2021-05-19  5:06         ` Greg Kroah-Hartman
@ 2021-05-19 14:43         ` Alan Stern
  2021-05-19 23:07           ` Matthias Kaehlcke
  1 sibling, 1 reply; 21+ messages in thread
From: Alan Stern @ 2021-05-19 14:43 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> 
> Could you also have a look at "[4/5] usb: host: xhci-plat:
> Create platform device for onboard hubs in probe()"
> (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> relatively short patch that creates the platform device for
> the driver from xhci-plat as you suggested in the v4
> discussion.

I'm not the maintainer for xhci-related drivers.

However, there is at least one thing about this patch which looks 
suspicious: Adding the onboard_hub_dev pointer to struct usb_hcd instead 
of to struct xhci_plat_priv, where it would make a lot more sense.

It's also worth mentioning that this approach won't work at all when the 
onboard hub is not at the top level (its parent isn't the root hub), or 
when more than one onboard hubs are connected to the same root hub.

Alan Stern

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-19 14:43         ` Alan Stern
@ 2021-05-19 23:07           ` Matthias Kaehlcke
  2021-05-20  2:05             ` Alan Stern
  0 siblings, 1 reply; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-19 23:07 UTC (permalink / raw)
  To: Alan Stern
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Wed, May 19, 2021 at 10:43:56AM -0400, Alan Stern wrote:
> On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> > 
> > Could you also have a look at "[4/5] usb: host: xhci-plat:
> > Create platform device for onboard hubs in probe()"
> > (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> > relatively short patch that creates the platform device for
> > the driver from xhci-plat as you suggested in the v4
> > discussion.
> 
> I'm not the maintainer for xhci-related drivers.
> 
> However, there is at least one thing about this patch which looks 
> suspicious: Adding the onboard_hub_dev pointer to struct usb_hcd instead 
> of to struct xhci_plat_priv, where it would make a lot more sense.

I can move it to struct usb_hcd if that's preferred

> It's also worth mentioning that this approach won't work at all when the 
> onboard hub is not at the top level (its parent isn't the root hub),

Yes, this limitation is mentioned in the commit message of '[2/5] USB:
misc: Add onboard_usb_hub driver'. It shouldn't be hard to add support
for nested hubs, however I currently have no such configuration for
testing, so I prefer to defer it until the need actually arises and
it can be tested.

> or when more than one onboard hubs are connected to the same root hub.

Right, currently that isn't supported. xhci-plat could iterate over the
ports and have a list of the platform devices it owns. It would also
require some logic to make sure only one platform device is created per
hub. Much of this code could probably live in the onboard_hub driver
and would also be used if support for non-root hubs is added.

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-19 23:07           ` Matthias Kaehlcke
@ 2021-05-20  2:05             ` Alan Stern
  2021-05-20 13:41               ` Matthias Kaehlcke
  0 siblings, 1 reply; 21+ messages in thread
From: Alan Stern @ 2021-05-20  2:05 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Wed, May 19, 2021 at 04:07:17PM -0700, Matthias Kaehlcke wrote:
> On Wed, May 19, 2021 at 10:43:56AM -0400, Alan Stern wrote:
> > On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> > > 
> > > Could you also have a look at "[4/5] usb: host: xhci-plat:
> > > Create platform device for onboard hubs in probe()"
> > > (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> > > relatively short patch that creates the platform device for
> > > the driver from xhci-plat as you suggested in the v4
> > > discussion.
> > 
> > I'm not the maintainer for xhci-related drivers.
> > 
> > However, there is at least one thing about this patch which looks 
> > suspicious: Adding the onboard_hub_dev pointer to struct usb_hcd instead 
> > of to struct xhci_plat_priv, where it would make a lot more sense.
> 
> I can move it to struct usb_hcd if that's preferred

Thinko: The patch already has it in struct usb_hcd.  I suggested moving 
it to struct xhci_plat_priv.

Alan Stern

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-20  2:05             ` Alan Stern
@ 2021-05-20 13:41               ` Matthias Kaehlcke
  2021-05-20 21:14                 ` Matthias Kaehlcke
  0 siblings, 1 reply; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-20 13:41 UTC (permalink / raw)
  To: Alan Stern
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Wed, May 19, 2021 at 10:05:21PM -0400, Alan Stern wrote:
> On Wed, May 19, 2021 at 04:07:17PM -0700, Matthias Kaehlcke wrote:
> > On Wed, May 19, 2021 at 10:43:56AM -0400, Alan Stern wrote:
> > > On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> > > > 
> > > > Could you also have a look at "[4/5] usb: host: xhci-plat:
> > > > Create platform device for onboard hubs in probe()"
> > > > (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> > > > relatively short patch that creates the platform device for
> > > > the driver from xhci-plat as you suggested in the v4
> > > > discussion.
> > > 
> > > I'm not the maintainer for xhci-related drivers.
> > > 
> > > However, there is at least one thing about this patch which looks 
> > > suspicious: Adding the onboard_hub_dev pointer to struct usb_hcd instead 
> > > of to struct xhci_plat_priv, where it would make a lot more sense.
> > 
> > I can move it to struct usb_hcd if that's preferred
> 
> Thinko: The patch already has it in struct usb_hcd.  I suggested moving 
> it to struct xhci_plat_priv.

Ah, didn't actively recall to which struct I added it to, it has been a
while since I wrote that patch ;-) Agreed that struct xhci_plat_priv is
a better place.

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-20 13:41               ` Matthias Kaehlcke
@ 2021-05-20 21:14                 ` Matthias Kaehlcke
  2021-05-21  1:14                   ` Alan Stern
  0 siblings, 1 reply; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-20 21:14 UTC (permalink / raw)
  To: Alan Stern
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Thu, May 20, 2021 at 06:41:23AM -0700, Matthias Kaehlcke wrote:
> On Wed, May 19, 2021 at 10:05:21PM -0400, Alan Stern wrote:
> > On Wed, May 19, 2021 at 04:07:17PM -0700, Matthias Kaehlcke wrote:
> > > On Wed, May 19, 2021 at 10:43:56AM -0400, Alan Stern wrote:
> > > > On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> > > > > 
> > > > > Could you also have a look at "[4/5] usb: host: xhci-plat:
> > > > > Create platform device for onboard hubs in probe()"
> > > > > (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> > > > > relatively short patch that creates the platform device for
> > > > > the driver from xhci-plat as you suggested in the v4
> > > > > discussion.
> > > > 
> > > > I'm not the maintainer for xhci-related drivers.
> > > > 
> > > > However, there is at least one thing about this patch which looks 
> > > > suspicious: Adding the onboard_hub_dev pointer to struct usb_hcd instead 
> > > > of to struct xhci_plat_priv, where it would make a lot more sense.
> > > 
> > > I can move it to struct usb_hcd if that's preferred
> > 
> > Thinko: The patch already has it in struct usb_hcd.  I suggested moving 
> > it to struct xhci_plat_priv.
> 
> Ah, didn't actively recall to which struct I added it to, it has been a
> while since I wrote that patch ;-)

> Agreed that struct xhci_plat_priv is a better place.

Or not, xhci_plat_priv is optional, which doesn't make it a good candidate
for holding a field that could be used by any xHCI controller.

Should I move the field to struct xhci_hcd instead?

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-20 21:14                 ` Matthias Kaehlcke
@ 2021-05-21  1:14                   ` Alan Stern
  2021-05-25 17:20                     ` Matthias Kaehlcke
  0 siblings, 1 reply; 21+ messages in thread
From: Alan Stern @ 2021-05-21  1:14 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Thu, May 20, 2021 at 02:14:15PM -0700, Matthias Kaehlcke wrote:
> On Thu, May 20, 2021 at 06:41:23AM -0700, Matthias Kaehlcke wrote:
> > On Wed, May 19, 2021 at 10:05:21PM -0400, Alan Stern wrote:
> > > On Wed, May 19, 2021 at 04:07:17PM -0700, Matthias Kaehlcke wrote:
> > > > On Wed, May 19, 2021 at 10:43:56AM -0400, Alan Stern wrote:
> > > > > On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> > > > > > 
> > > > > > Could you also have a look at "[4/5] usb: host: xhci-plat:
> > > > > > Create platform device for onboard hubs in probe()"
> > > > > > (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> > > > > > relatively short patch that creates the platform device for
> > > > > > the driver from xhci-plat as you suggested in the v4
> > > > > > discussion.
> > > > > 
> > > > > I'm not the maintainer for xhci-related drivers.
> > > > > 
> > > > > However, there is at least one thing about this patch which looks 
> > > > > suspicious: Adding the onboard_hub_dev pointer to struct usb_hcd instead 
> > > > > of to struct xhci_plat_priv, where it would make a lot more sense.
> > > > 
> > > > I can move it to struct usb_hcd if that's preferred
> > > 
> > > Thinko: The patch already has it in struct usb_hcd.  I suggested moving 
> > > it to struct xhci_plat_priv.
> > 
> > Ah, didn't actively recall to which struct I added it to, it has been a
> > while since I wrote that patch ;-)
> 
> > Agreed that struct xhci_plat_priv is a better place.
> 
> Or not, xhci_plat_priv is optional, which doesn't make it a good candidate
> for holding a field that could be used by any xHCI controller.

You could always allocate an xhci_plat_priv structure in cases where an 
onboard-hub device is present, if one doesn't exist already.

> Should I move the field to struct xhci_hcd instead?

That's another option.

Look, I'm not the person you should be asking about this.  What I say 
doesn't matter -- you need to get approval from Mathias Nyman, the 
xhci-hcd maintainer.

Alan Stern

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver
  2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
                   ` (5 preceding siblings ...)
  2021-05-12  7:19 ` [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Alexander Dahl
@ 2021-05-21 12:30 ` Greg Kroah-Hartman
  2021-05-25 17:42   ` Matthias Kaehlcke
  6 siblings, 1 reply; 21+ messages in thread
From: Greg Kroah-Hartman @ 2021-05-21 12:30 UTC (permalink / raw)
  To: Matthias Kaehlcke
  Cc: Alan Stern, Rob Herring, Frank Rowand, Michal Simek, devicetree,
	Douglas Anderson, linux-usb, Peter Chen, linux-kernel,
	Stephen Boyd, Ravi Chandra Sadineni, Krzysztof Kozlowski,
	Bastien Nocera, Al Cooper, Alexander A. Klimov, Andy Gross,
	Bjorn Andersson, Christian Lamparter, Colin Ian King,
	Dmitry Osipenko, Fabio Estevam, Masahiro Yamada, Mathias Nyman,
	Vinod Koul, linux-arm-msm

On Tue, May 11, 2021 at 03:52:18PM -0700, Matthias Kaehlcke wrote:
> This series adds:
> - the onboard_usb_hub_driver
> - glue in the xhci-plat driver to create the onboard_usb_hub
>   platform device if needed
> - a device tree binding for the Realtek RTS5411 USB hub controller
> - device tree changes that add RTS5411 entries for the QCA SC7180
>   based boards trogdor and lazor
> - a couple of stubs for platform device functions to avoid
>   unresolved symbols with certain kernel configs
> 
> The main issue the driver addresses is that a USB hub needs to be
> powered before it can be discovered. For discrete onboard hubs (an
> example for such a hub is the Realtek RTS5411) this is often solved
> by supplying the hub with an 'always-on' regulator, which is kind
> of a hack. Some onboard hubs may require further initialization
> steps, like changing the state of a GPIO or enabling a clock, which
> requires even more hacks. This driver creates a platform device
> representing the hub which performs the necessary initialization.
> Currently it only supports switching on a single regulator, support
> for multiple regulators or other actions can be added as needed.
> Different initialization sequences can be supported based on the
> compatible string.
> 
> Besides performing the initialization the driver can be configured
> to power the hub off during system suspend. This can help to extend
> battery life on battery powered devices which have no requirements
> to keep the hub powered during suspend. The driver can also be
> configured to leave the hub powered when a wakeup capable USB device
> is connected when suspending, and power it off otherwise.

I get a build error when I apply this series to my tree:

drivers/usb/misc/onboard_usb_hub.c:273:6: error: redefinition of ‘of_is_onboard_usb_hub’
  273 | bool of_is_onboard_usb_hub(const struct device_node *np)
      |      ^~~~~~~~~~~~~~~~~~~~~
In file included from drivers/usb/misc/onboard_usb_hub.c:21:
./include/linux/usb/onboard_hub.h:9:20: note: previous definition of ‘of_is_onboard_usb_hub’ with type ‘bool(const struct device_node *)’ {aka ‘_Bool(const struct device_node *)’}
    9 | static inline bool of_is_onboard_usb_hub(const struct device_node *np)
      |                    ^~~~~~~~~~~~~~~~~~~~~

Any thoughts?

greg k-h

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver
  2021-05-21  1:14                   ` Alan Stern
@ 2021-05-25 17:20                     ` Matthias Kaehlcke
  0 siblings, 0 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-25 17:20 UTC (permalink / raw)
  To: Alan Stern
  Cc: Greg Kroah-Hartman, Rob Herring, Frank Rowand, Michal Simek,
	devicetree, Douglas Anderson, linux-usb, Peter Chen,
	linux-kernel, Stephen Boyd, Ravi Chandra Sadineni,
	Krzysztof Kozlowski, Bastien Nocera, Al Cooper,
	Alexander A. Klimov, Masahiro Yamada

On Thu, May 20, 2021 at 09:14:36PM -0400, Alan Stern wrote:
> On Thu, May 20, 2021 at 02:14:15PM -0700, Matthias Kaehlcke wrote:
> > On Thu, May 20, 2021 at 06:41:23AM -0700, Matthias Kaehlcke wrote:
> > > On Wed, May 19, 2021 at 10:05:21PM -0400, Alan Stern wrote:
> > > > On Wed, May 19, 2021 at 04:07:17PM -0700, Matthias Kaehlcke wrote:
> > > > > On Wed, May 19, 2021 at 10:43:56AM -0400, Alan Stern wrote:
> > > > > > On Tue, May 18, 2021 at 02:40:47PM -0700, Matthias Kaehlcke wrote:
> > > > > > > 
> > > > > > > Could you also have a look at "[4/5] usb: host: xhci-plat:
> > > > > > > Create platform device for onboard hubs in probe()"
> > > > > > > (https://lore.kernel.org/patchwork/patch/1425453/)? It's a
> > > > > > > relatively short patch that creates the platform device for
> > > > > > > the driver from xhci-plat as you suggested in the v4
> > > > > > > discussion.
> > > > > > 
> > > > > > I'm not the maintainer for xhci-related drivers.
> > > > > > 
> > > > > > However, there is at least one thing about this patch which looks 
> > > > > > suspicious: Adding the onboard_hub_dev pointer to struct usb_hcd instead 
> > > > > > of to struct xhci_plat_priv, where it would make a lot more sense.
> > > > > 
> > > > > I can move it to struct usb_hcd if that's preferred
> > > > 
> > > > Thinko: The patch already has it in struct usb_hcd.  I suggested moving 
> > > > it to struct xhci_plat_priv.
> > > 
> > > Ah, didn't actively recall to which struct I added it to, it has been a
> > > while since I wrote that patch ;-)
> > 
> > > Agreed that struct xhci_plat_priv is a better place.
> > 
> > Or not, xhci_plat_priv is optional, which doesn't make it a good candidate
> > for holding a field that could be used by any xHCI controller.
> 
> You could always allocate an xhci_plat_priv structure in cases where an 
> onboard-hub device is present, if one doesn't exist already.

that's an option, thanks for the suggestion.

> > Should I move the field to struct xhci_hcd instead?
> 
> That's another option.
> 
> Look, I'm not the person you should be asking about this.  What I say 
> doesn't matter -- you need to get approval from Mathias Nyman, the 
> xhci-hcd maintainer.

ok, thanks

^ permalink raw reply	[flat|nested] 21+ messages in thread

* Re: [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver
  2021-05-21 12:30 ` Greg Kroah-Hartman
@ 2021-05-25 17:42   ` Matthias Kaehlcke
  0 siblings, 0 replies; 21+ messages in thread
From: Matthias Kaehlcke @ 2021-05-25 17:42 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: Alan Stern, Rob Herring, Frank Rowand, Michal Simek, devicetree,
	Douglas Anderson, linux-usb, Peter Chen, linux-kernel,
	Stephen Boyd, Ravi Chandra Sadineni, Krzysztof Kozlowski,
	Bastien Nocera, Al Cooper, Alexander A. Klimov, Andy Gross,
	Bjorn Andersson, Christian Lamparter, Colin Ian King,
	Dmitry Osipenko, Fabio Estevam, Masahiro Yamada, Mathias Nyman,
	Vinod Koul, linux-arm-msm

On Fri, May 21, 2021 at 02:30:39PM +0200, Greg Kroah-Hartman wrote:
> On Tue, May 11, 2021 at 03:52:18PM -0700, Matthias Kaehlcke wrote:
> > This series adds:
> > - the onboard_usb_hub_driver
> > - glue in the xhci-plat driver to create the onboard_usb_hub
> >   platform device if needed
> > - a device tree binding for the Realtek RTS5411 USB hub controller
> > - device tree changes that add RTS5411 entries for the QCA SC7180
> >   based boards trogdor and lazor
> > - a couple of stubs for platform device functions to avoid
> >   unresolved symbols with certain kernel configs
> > 
> > The main issue the driver addresses is that a USB hub needs to be
> > powered before it can be discovered. For discrete onboard hubs (an
> > example for such a hub is the Realtek RTS5411) this is often solved
> > by supplying the hub with an 'always-on' regulator, which is kind
> > of a hack. Some onboard hubs may require further initialization
> > steps, like changing the state of a GPIO or enabling a clock, which
> > requires even more hacks. This driver creates a platform device
> > representing the hub which performs the necessary initialization.
> > Currently it only supports switching on a single regulator, support
> > for multiple regulators or other actions can be added as needed.
> > Different initialization sequences can be supported based on the
> > compatible string.
> > 
> > Besides performing the initialization the driver can be configured
> > to power the hub off during system suspend. This can help to extend
> > battery life on battery powered devices which have no requirements
> > to keep the hub powered during suspend. The driver can also be
> > configured to leave the hub powered when a wakeup capable USB device
> > is connected when suspending, and power it off otherwise.
> 
> I get a build error when I apply this series to my tree:
> 
> drivers/usb/misc/onboard_usb_hub.c:273:6: error: redefinition of ‘of_is_onboard_usb_hub’
>   273 | bool of_is_onboard_usb_hub(const struct device_node *np)
>       |      ^~~~~~~~~~~~~~~~~~~~~
> In file included from drivers/usb/misc/onboard_usb_hub.c:21:
> ./include/linux/usb/onboard_hub.h:9:20: note: previous definition of ‘of_is_onboard_usb_hub’ with type ‘bool(const struct device_node *)’ {aka ‘_Bool(const struct device_node *)’}
>     9 | static inline bool of_is_onboard_usb_hub(const struct device_node *np)
>       |                    ^~~~~~~~~~~~~~~~~~~~~
> 
> Any thoughts?

That function keeps haunting me in different ways ...

I suspect this was a build with CONFIG_COMPILE_TEST=y. The driver is
compiled for such a config and has the actual implementation, however
the header defines the static inline unless CONFIG_USB_ONBOARD_HUB=y/m.

I realized earlier that the driver doesn't really need to include the
header, and planned to remove it in the next version, which might be
the most practical solution.

^ permalink raw reply	[flat|nested] 21+ messages in thread

end of thread, other threads:[~2021-05-25 17:42 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-11 22:52 [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
2021-05-11 22:52 ` [PATCH v10 1/5] dt-bindings: usb: Add binding for Realtek RTS5411 hub controller Matthias Kaehlcke
2021-05-11 22:52 ` [PATCH v10 2/5] USB: misc: Add onboard_usb_hub driver Matthias Kaehlcke
2021-05-18 17:05   ` Matthias Kaehlcke
2021-05-18 19:45     ` Alan Stern
2021-05-18 21:40       ` Matthias Kaehlcke
2021-05-19  5:06         ` Greg Kroah-Hartman
2021-05-19 14:43         ` Alan Stern
2021-05-19 23:07           ` Matthias Kaehlcke
2021-05-20  2:05             ` Alan Stern
2021-05-20 13:41               ` Matthias Kaehlcke
2021-05-20 21:14                 ` Matthias Kaehlcke
2021-05-21  1:14                   ` Alan Stern
2021-05-25 17:20                     ` Matthias Kaehlcke
2021-05-11 22:52 ` [PATCH v10 3/5] of/platform: Add stubs for of_platform_device_create/destroy() Matthias Kaehlcke
2021-05-11 22:52 ` [PATCH v10 4/5] usb: host: xhci-plat: Create platform device for onboard hubs in probe() Matthias Kaehlcke
2021-05-11 22:52 ` [PATCH v10 5/5] arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub Matthias Kaehlcke
2021-05-12  7:19 ` [PATCH v10 0/5] USB: misc: Add onboard_usb_hub driver Alexander Dahl
2021-05-12 16:37   ` Matthias Kaehlcke
2021-05-21 12:30 ` Greg Kroah-Hartman
2021-05-25 17:42   ` Matthias Kaehlcke

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