This series adds:
- the onboard_usb_hub_driver
- glue in the generic hub code to create and destroy the
onboard_usb_hub platform devices if needed
- 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 v24:
- changed USB_ONBOARD_HUB from bool to tristate and fixed Makefile
entry
- renamed 'companion-hub' property to 'peer-hub'
- added comment to onboard_hub_create_pdevs() doc that explains the
somewhat convoluted logic of the function
- only cancel the driver attach work in onboard_hub_remove() if the
function wasn't called by the work job itself
- added patch "dt-bindings: usb: rts5411: Rename property
'companion-hub' to 'peer-hub'"
Changes in v23:
- refactored onboard_hub_create_pdevs()
- got rid of CONFIG_USB_ONBOARD_HUB_ACTUAL
Changes in v22:
- call onboard_hub_create/destroy_pdevs() from hub_probe/disconnect()
instead of doing it from the HCD. When the pdevs are create from the
HCD usb_of_get_device_node() (called by onboard_hub_create_pdevs())
may return NULL because the USB device for the root hub doesn't
exist yet. Creating the pdevs from the hub code also has the
advantage of enabling support for nested onboard hubs (as long as
all hubs in the chain have DT nodes and are supported by the driver).
- moved onboard_hub_create_pdevs(), onboard_hub_destroy_pdevs() and
of_is_onboard_usb_hub() into a separate file to allow them to be
linked into the USB core module (if CONFIG_USB=m)
- Added extra checks to ensure only one platform device is created
for each physical hub. This is necessary because
onboard_hub_create_pdevs() is now called from hub_probe() instead
of usb_add_hcd(). As a result the function is called twice for
typical USB3 hub, once for the USB3 part of the hub, and once for
USB <= 2.x. Generally the parent hub downstream of the primary HCD
creates the onboard hub platform device.
- use kzalloc() instead of devm_kzalloc() to allocate list entries. Using
managed memory can cause issues since the managed memory is allocated
before the device is probed.
- use a workqueue to (re-)attach the USB driver during/after _probe().
This is necessary to avoid self-deadlocks on systems with nested
onboard hubs.
- don't initialize list_head in onboard_hub_create_pdevs(), this needs
to be done by the owner, to ensure that onboard_hub_destroy_pdevs()
is called with a struct that was properly initialized even when
onboard_hub_create_pdevs() is not called.
- rebased series on v5.19-rc1
Changes in v21:
- dropped patch 'driver core: Export device_is_bound()'
- refactored _find_onboard_hub()
- removed 'onboard_hub_dev' symlinks from USB devices
- dropped patch 'arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub'
(will be sent separately)
- rebased series on v5.17-rc4
Changes in v20:
- addressed review comments from Stephen
- changed DT node names for hubs
Changes in v19:
- added VID:PID pairs and compatible strings for RTS5414 hub
- updated comments with RTS5411 USB versions to reflect those
reported/supported by the hub
- rebased series on v5.16
Changes in v18:
- introduced hidden Kconfig option to align module vs. builtin
choice with CONFIG_USB (thanks Doug!)
- added patch 'driver core: Export device_is_bound()'
- also adjust device tree of pompom rev1
- dropped the following patches, which aren't needed anymore by this
series (though they might still be useful on their own):
- usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
- arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
- ARM: configs: Explicitly enable USB_XHCI_PLATFORM where needed
Changes in v17:
- rebased on top of v5.16-rc1
- moved creation of onboard_hub platform devices from xhci_platform
to the generic HCD code
- addressed review comments for the onboard_hub driver
- moved Kconfig/defconfig changes to the end of the series. The
onboard_hub driver doesn't depend on XHCI_PLATFORM anymore,
hence these changes aren't really required for the driver, but
they still seem to be a worthwhile improvement
Changes in v16:
- added patch 'ARM: configs: Explicitly enable USB_XHCI_PLATFORM
where needed' to keep arm32 defconfigs effectively unchanged
Changes in v15:
- adjusted dependencies of USB_DWC3_CORE to make sure it can only
be enabled when at least one of USB_DWC3_HOST, USB_DWC3_GADGET
or USB_DWC3_DUAL_ROLE is selectable
Changes in v14:
- rebased on top of v5.14-rc1
- dropped DT binding patch which landed in v5.13
Changes in v13:
- added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
'depends on'" to the series to avoid Kconfig conflicts
- added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
to the series to keep effective defconfig unchanged
Changes in v12:
- onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
in onboard_hub.h to also check for the driver built as module
- onboard_hub_driver: include onboard_hub.h again to make sure there
are prototype declarations for the public functions
Changes in v11:
- support multiple onboard hubs connected to the same parent
- don't include ‘onboard_hub.h’ from the onboard hub driver
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 (4):
of/platform: Add stubs for of_platform_device_create/destroy()
dt-bindings: usb: rts5411: Rename property 'companion-hub' to
'peer-hub'
usb: misc: Add onboard_usb_hub driver
usb: core: hub: Create platform devices for onboard hubs in
hub_probe()
.../sysfs-bus-platform-onboard-usb-hub | 8 +
.../bindings/usb/realtek,rts5411.yaml | 10 +-
MAINTAINERS | 7 +
drivers/usb/core/Makefile | 4 +
drivers/usb/core/hub.c | 9 +-
drivers/usb/core/hub.h | 1 +
drivers/usb/misc/Kconfig | 16 +
drivers/usb/misc/Makefile | 1 +
drivers/usb/misc/onboard_usb_hub.c | 428 ++++++++++++++++++
drivers/usb/misc/onboard_usb_hub.h | 17 +
drivers/usb/misc/onboard_usb_hub_pdevs.c | 142 ++++++
include/linux/of_platform.h | 22 +-
include/linux/usb/onboard_hub.h | 18 +
13 files changed, 673 insertions(+), 10 deletions(-)
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 drivers/usb/misc/onboard_usb_hub.h
create mode 100644 drivers/usb/misc/onboard_usb_hub_pdevs.c
create mode 100644 include/linux/usb/onboard_hub.h
--
2.37.0.rc0.161.g10f37bed90-goog
Call onboard_hub_create/destroy_pdevs() from hub_probe/disconnect()
to create/destroy platform devices for onboard USB hubs that may be
connected to the hub. The onboard hubs must have nodes in the
device tree.
onboard_hub_create/destroy_pdevs() are NOPs unless
CONFIG_USB_ONBOARD_HUB=y/m.
Also add a field to struct usb_hub to keep track of the onboard hub
platform devices that are owned by the hub.
Signed-off-by: Matthias Kaehlcke <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
---
Changes in v24:
- none
Changes in v23:
- added Doug's 'Reviewed-by' tag
Changes in v22:
- patch added to the series (moved creation/deletion from HCD)
drivers/usb/core/hub.c | 9 ++++++++-
drivers/usb/core/hub.h | 1 +
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 68e9121c1878..8055130ee602 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -23,6 +23,7 @@
#include <linux/usb.h>
#include <linux/usbdevice_fs.h>
#include <linux/usb/hcd.h>
+#include <linux/usb/onboard_hub.h>
#include <linux/usb/otg.h>
#include <linux/usb/quirks.h>
#include <linux/workqueue.h>
@@ -1752,6 +1753,8 @@ static void hub_disconnect(struct usb_interface *intf)
if (hub->quirk_disable_autosuspend)
usb_autopm_put_interface(intf);
+ onboard_hub_destroy_pdevs(&hub->onboard_hub_devs);
+
kref_put(&hub->kref, hub_release);
}
@@ -1869,6 +1872,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
INIT_DELAYED_WORK(&hub->leds, led_work);
INIT_DELAYED_WORK(&hub->init_work, NULL);
INIT_WORK(&hub->events, hub_event);
+ INIT_LIST_HEAD(&hub->onboard_hub_devs);
spin_lock_init(&hub->irq_urb_lock);
timer_setup(&hub->irq_urb_retry, hub_retry_irq_urb, 0);
usb_get_intf(intf);
@@ -1889,8 +1893,11 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
usb_autopm_get_interface_no_resume(intf);
}
- if (hub_configure(hub, &desc->endpoint[0].desc) >= 0)
+ if (hub_configure(hub, &desc->endpoint[0].desc) >= 0) {
+ onboard_hub_create_pdevs(hdev, &hub->onboard_hub_devs);
+
return 0;
+ }
hub_disconnect(intf);
return -ENODEV;
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 22ea1f4f2d66..ccf90052d12a 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -73,6 +73,7 @@ struct usb_hub {
spinlock_t irq_urb_lock;
struct timer_list irq_urb_retry;
struct usb_port **ports;
+ struct list_head onboard_hub_devs;
};
/**
--
2.37.0.rc0.161.g10f37bed90-goog
In the context of USB the term 'companion-hub' is misleading, change the
name of the property to 'peer-hub'.
There are no upstream users of the 'companion-hub' property, neither in
the device tree, nor on the driver side, so renaming it shouldn't cause
any compatibility issues with existing device trees.
Changes in v24:
- patch added to the series
Signed-off-by: Matthias Kaehlcke <[email protected]>
---
(no changes since v1)
.../devicetree/bindings/usb/realtek,rts5411.yaml | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/Documentation/devicetree/bindings/usb/realtek,rts5411.yaml b/Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
index 04ee255eb4f0..50f2b505bdeb 100644
--- a/Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
+++ b/Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
@@ -25,13 +25,13 @@ properties:
description:
phandle to the regulator that provides power to the hub.
- companion-hub:
+ peer-hub:
$ref: '/schemas/types.yaml#/definitions/phandle'
description:
- phandle to the companion hub on the controller.
+ phandle to the peer hub on the controller.
required:
- - companion-hub
+ - peer-hub
- compatible
- reg
@@ -49,7 +49,7 @@ examples:
compatible = "usbbda,5411";
reg = <1>;
vdd-supply = <&pp3300_hub>;
- companion-hub = <&hub_3_0>;
+ peer-hub = <&hub_3_0>;
};
/* 3.0 hub on port 2 */
@@ -57,6 +57,6 @@ examples:
compatible = "usbbda,411";
reg = <2>;
vdd-supply = <&pp3300_hub>;
- companion-hub = <&hub_2_0>;
+ peer-hub = <&hub_2_0>;
};
};
--
2.37.0.rc0.161.g10f37bed90-goog
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).
Co-developed-by: Ravi Chandra Sadineni <[email protected]>
Signed-off-by: Ravi Chandra Sadineni <[email protected]>
Signed-off-by: Matthias Kaehlcke <[email protected]>
---
Changes in v24:
- changed USB_ONBOARD_HUB from bool to tristate and fixed Makefile
entry
- renamed 'companion-hub' property to 'peer-hub'
- added comment to onboard_hub_create_pdevs() doc that explains the
somewhat convoluted logic of the function
- only cancel the driver attach work in onboard_hub_remove() if the
function wasn't called by the work itself
Changes in v23:
- refactored onboard_hub_create_pdevs()
- bail out before the loop for root hubs connected to
the secondary HCD
- check for exisiting pdev in the companion hub branch
instead of doing it afterwards
- added note about the role of the platform devices to
documentation of onboard_hub_create_pdevs()
- got rid of CONFIG_USB_ONBOARD_HUB_ACTUAL, it's not needed anymore
now that onboard_hub_create/destroy_pdevs() are linked into the USB
core
- added some more details to comment about the need to re-attach the
USB driver
Changes in v22:
- moved onboard_hub_create_pdevs(), onboard_hub_destroy_pdevs() and
of_is_onboard_usb_hub() into a separate file to allow them to be
linked into the USB core module (if CONFIG_USB=m)
- Added extra checks to ensure only one platform device is created
for each physical hub. This is necessary because
onboard_hub_create_pdevs() is now called from hub_probe() instead
of usb_add_hcd(). As a result the function is called twice for
typical USB3 hub, once for the USB3 part of the hub, and once for
USB <= 2.x. Generally the parent hub downstream of the primary HCD
creates the onboard hub platform device.
- use kzalloc() instead of devm_kzalloc() to allocate list entries. Using
managed memory can cause issues since the managed memory is allocated
before the device is probed.
- use a workqueue to (re-)attach the USB driver during/after _probe().
This is necessary to avoid self-deadlocks on systems with nested
onboard hubs.
- don't initialize list_head in onboard_hub_create_pdevs(), this needs
to be done by the owner, to ensure that onboard_hub_destroy_pdevs()
is called with a struct that was properly initialized even when
onboard_hub_create_pdevs() is not called.
- moved 'onboard_hub_match' into an include, so it can be used
by both the the onboard hub driver and of_is_onboard_usb_hub()
- removed note from the commit message which said that currently only
onboard hubs connected to a root hub are supported. This isn't the
case anymore.
- updated kernel version and date in sysfs documentation
- removed tags from Doug and Alan since this version changes quite
a few things
Changes in v21:
- refactored _find_onboard_hub()
- check presence of drvdata instead of using device_is_bound()
- return -ENODEV if the platform device can't be found
- always check drvdata, not only when looking for the companion
hub
- added comment explaining probe deferral
- removed 'onboard_hub_dev' symlinks from USB devices
- updated documentation of 'always_powered_in_suspend' sysfs attribute
Changes in v20:
- s/nontrivial/non-trivial/ in Kconfig doc
- added include of 'export.h'
- initialize variable 'power_off' in onboard_hub_suspend() at
declaration time
- renamed set_udev_link_name() to get_udev_link_name()
- use kzalloc to allocate struct usbdev_node instead of devm_kzalloc()
- release the lock in onboard_hub_add_usbdev() before calling
get_udev_link_name()
- free struct usbdev_node in onboard_hub_remove_usbdev(), now that
it doesn't used managed memory
- make struct onboard_hub const in always_powered_in_suspend_show()
- call put_device() if pdev is not bound in _find_onboard_hub()
- get driver data before calling put_device() in _find_onboard_hub()
- log platform device name when sysfs link creation fails in
onboard_hub_usbdev_probe()
- added kernel doc for onboard_hub_create_pdevs() and
onboard_hub_destroy_pdevs()
- added 'Reviewed-by' tag from Doug
Changes in v19:
- added VID:PID pairs and compatible strings for RTS5414 hub
- updated comments with RTS5411 USB versions to reflect those
reported/supported by the hub
Changes in v18:
- introduced hidden Kconfig option to align module vs. builtin
choice with CONFIG_USB (thanks Doug!)
- refactored onboard_hub_create_pdevs()
Changes in v17:
- updated date and kernel version in ABI documentation for
'always_powered_in_suspend' attribute
- removed obsolete .yaml entry from MAINTAINERS file
- added entry for ABI documentation to MAINTAINERS file
- renamed struct 'udev_node' to 'usbdev_node'
- changed return logic in onboard_hub_suspend/resume() to
get rid of 'rc' variable
- added helper set_udev_link_name() to set link names for
onboard hub USB devices
- use of_parse_phandle() instead of of_property_read_u32() +
of_find_node_by_phandle() combo
- defer probing in _find_onboard_hub() if the platform device
isn't bound yet
- initialize list head passed as parameter to
onboard_hub_create_pdevs() instead of relying on the caller
to do so
- don't require the 'companion-hub' property to be specified.
This is needed to support hubs without companion hub
- use devm_kzalloc() to allocate platform device list entries
and stop freeing them explicitly
- remove unnecessary INIT_LIST_HEAD() of platform device list
entries
- use '%pOF' to print DT node name
- delete platform device list entries from the list of devices
in onboard_hub_destroy_pdevs(). It shouldn't be strictly
necessary, but better be on the safe side.
Changes in v16:
- none
Changes in v15:
- none
Changes in v14:
- none
Changes in v13:
- none
Changes in v12:
- use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE) in onboard_hub.h to
also check for the driver built as module
- include onboard_hub.h again from the driver to make sure there are
prototype declarations for the public functions
- remove indentation from label in onboard_hub_create_pdevs()
Changes in v11:
- added onboard_hub_create/destroy_pdevs() helpers, to support multiple onboard
hubs connected to the same parent hub
- don't include ‘onboard_hub.h’ from the onboard hub driver
- updated commit message
- added ‘Acked-by' from Alan
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/core/Makefile | 4 +
drivers/usb/misc/Kconfig | 16 +
drivers/usb/misc/Makefile | 1 +
drivers/usb/misc/onboard_usb_hub.c | 428 ++++++++++++++++++
drivers/usb/misc/onboard_usb_hub.h | 17 +
drivers/usb/misc/onboard_usb_hub_pdevs.c | 142 ++++++
include/linux/usb/onboard_hub.h | 18 +
9 files changed, 641 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 drivers/usb/misc/onboard_usb_hub.h
create mode 100644 drivers/usb/misc/onboard_usb_hub_pdevs.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..42deb0552065
--- /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: June 2022
+KernelVersion: 5.20
+Contact: Matthias Kaehlcke <[email protected]>
+ [email protected]
+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 3cf9842d9233..8ae44cd423a3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14795,6 +14795,13 @@ S: Maintained
T: git git://linuxtv.org/media_tree.git
F: drivers/media/i2c/ov9734.c
+ONBOARD USB HUB DRIVER
+M: Matthias Kaehlcke <[email protected]>
+L: [email protected]
+S: Maintained
+F: Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
+F: drivers/usb/misc/onboard_usb_hub.c
+
ONENAND FLASH DRIVER
M: Kyungmin Park <[email protected]>
L: [email protected]
diff --git a/drivers/usb/core/Makefile b/drivers/usb/core/Makefile
index 18e874b0441e..7d338e9c0657 100644
--- a/drivers/usb/core/Makefile
+++ b/drivers/usb/core/Makefile
@@ -12,6 +12,10 @@ usbcore-$(CONFIG_OF) += of.o
usbcore-$(CONFIG_USB_PCI) += hcd-pci.o
usbcore-$(CONFIG_ACPI) += usb-acpi.o
+ifdef CONFIG_USB_ONBOARD_HUB
+usbcore-y += ../misc/onboard_usb_hub_pdevs.o
+endif
+
obj-$(CONFIG_USB) += usbcore.o
obj-$(CONFIG_USB_LEDS_TRIGGER_USBPORT) += ledtrig-usbport.o
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 4c5ddbd75b7e..9367c12c7e6f 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -295,3 +295,19 @@ 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 non-trivial form of initialization, such as enabling a
+ power regulator. An example for such a hub is the Realtek
+ RTS5411.
+
+ This driver can be used as a module but its state (module vs
+ builtin) must match the state of the USB subsystem. Enabling
+ this config will enable the driver and it will automatically
+ match the state of the USB subsystem. If this driver is a
+ module it will be called onboard_usb_hub.
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index 35bdb4b6c3b6..93581baec3a8 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -33,3 +33,4 @@ 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..6b9b949d17d3
--- /dev/null
+++ b/drivers/usb/misc/onboard_usb_hub.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for onboard USB hubs
+ *
+ * Copyright (c) 2022, Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.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/slab.h>
+#include <linux/suspend.h>
+#include <linux/sysfs.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/onboard_hub.h>
+#include <linux/workqueue.h>
+
+#include "onboard_usb_hub.h"
+
+static struct usb_device_driver onboard_hub_usbdev_driver;
+
+/************************** Platform driver **************************/
+
+struct usbdev_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 work_struct attach_usb_driver_work;
+ 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 usbdev_node *node;
+ bool power_off = true;
+
+ if (hub->always_powered_in_suspend)
+ return 0;
+
+ 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)
+ return 0;
+
+ return onboard_hub_power_off(hub);
+}
+
+static int __maybe_unused onboard_hub_resume(struct device *dev)
+{
+ struct onboard_hub *hub = dev_get_drvdata(dev);
+
+ if (hub->is_powered_on)
+ return 0;
+
+ return onboard_hub_power_on(hub);
+}
+
+static inline void get_udev_link_name(const struct usb_device *udev, char *buf, size_t size)
+{
+ snprintf(buf, size, "usb_dev.%s", dev_name(&udev->dev));
+}
+
+static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev)
+{
+ struct usbdev_node *node;
+ char link_name[64];
+ int err;
+
+ mutex_lock(&hub->lock);
+
+ if (hub->going_away) {
+ err = -EINVAL;
+ goto error;
+ }
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node) {
+ err = -ENOMEM;
+ goto error;
+ }
+
+ node->udev = udev;
+
+ list_add(&node->list, &hub->udev_list);
+
+ mutex_unlock(&hub->lock);
+
+ get_udev_link_name(udev, link_name, sizeof(link_name));
+ WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name));
+
+ return 0;
+
+error:
+ mutex_unlock(&hub->lock);
+
+ return err;
+}
+
+static void onboard_hub_remove_usbdev(struct onboard_hub *hub, const struct usb_device *udev)
+{
+ struct usbdev_node *node;
+ char link_name[64];
+
+ get_udev_link_name(udev, link_name, sizeof(link_name));
+ 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);
+ kfree(node);
+ break;
+ }
+ }
+
+ mutex_unlock(&hub->lock);
+}
+
+static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ const 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 void onboard_hub_attach_usb_driver(struct work_struct *work)
+{
+ int err;
+
+ err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver);
+ if (err)
+ pr_err("Failed to attach USB driver: %d\n", err);
+}
+
+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() (e.g. through an 'unbind' by userspace),
+ * make sure to re-attach it if needed.
+ *
+ * This needs to be done deferred to avoid self-deadlocks on systems
+ * with nested onboard hubs.
+ */
+ INIT_WORK(&hub->attach_usb_driver_work, onboard_hub_attach_usb_driver);
+ schedule_work(&hub->attach_usb_driver_work);
+
+ return 0;
+}
+
+static int onboard_hub_remove(struct platform_device *pdev)
+{
+ struct onboard_hub *hub = dev_get_drvdata(&pdev->dev);
+ struct usbdev_node *node;
+ struct usb_device *udev;
+
+ hub->going_away = true;
+
+ if (&hub->attach_usb_driver_work != current_work())
+ cancel_work_sync(&hub->attach_usb_driver_work);
+
+ 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 usbdev_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);
+}
+
+MODULE_DEVICE_TABLE(of, onboard_hub_match);
+
+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;
+ struct onboard_hub *hub;
+
+ pdev = of_find_device_by_node(dev->of_node);
+ if (!pdev) {
+ np = of_parse_phandle(dev->of_node, "peer-hub", 0);
+ if (!np) {
+ dev_err(dev, "failed to find device node for peer hub\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ pdev = of_find_device_by_node(np);
+ of_node_put(np);
+
+ if (!pdev)
+ return ERR_PTR(-ENODEV);
+ }
+
+ hub = dev_get_drvdata(&pdev->dev);
+ put_device(&pdev->dev);
+
+ /*
+ * The presence of drvdata ('hub') indicates that the platform driver
+ * finished probing. This handles the case where (conceivably) we could
+ * be running at the exact same time as the platform driver's probe. If
+ * we detect the race we request probe deferral and we'll come back and
+ * try again.
+ */
+ if (!hub)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return hub;
+}
+
+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;
+
+ return 0;
+}
+
+static void onboard_hub_usbdev_disconnect(struct usb_device *udev)
+{
+ struct onboard_hub *hub = dev_get_drvdata(&udev->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 3.1 */
+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 */
+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 */
+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 */
+ {}
+};
+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,
+};
+
+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 <[email protected]>");
+MODULE_DESCRIPTION("Driver for discrete onboard USB hubs");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/usb/misc/onboard_usb_hub.h b/drivers/usb/misc/onboard_usb_hub.h
new file mode 100644
index 000000000000..d3a5b6938582
--- /dev/null
+++ b/drivers/usb/misc/onboard_usb_hub.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2022, Google LLC
+ */
+
+#ifndef _USB_MISC_ONBOARD_USB_HUB_H
+#define _USB_MISC_ONBOARD_USB_HUB_H
+
+static const struct of_device_id onboard_hub_match[] = {
+ { .compatible = "usbbda,411" },
+ { .compatible = "usbbda,5411" },
+ { .compatible = "usbbda,414" },
+ { .compatible = "usbbda,5414" },
+ {}
+};
+
+#endif /* _USB_MISC_ONBOARD_USB_HUB_H */
diff --git a/drivers/usb/misc/onboard_usb_hub_pdevs.c b/drivers/usb/misc/onboard_usb_hub_pdevs.c
new file mode 100644
index 000000000000..a0a5f719129f
--- /dev/null
+++ b/drivers/usb/misc/onboard_usb_hub_pdevs.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * API for creating and destroying USB onboard hub platform devices
+ *
+ * Copyright (c) 2022, Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/of.h>
+
+#include "onboard_usb_hub.h"
+
+struct pdev_list_entry {
+ struct platform_device *pdev;
+ struct list_head node;
+};
+
+static bool of_is_onboard_usb_hub(const struct device_node *np)
+{
+ return !!of_match_node(onboard_hub_match, np);
+}
+
+/**
+ * onboard_hub_create_pdevs -- create platform devices for onboard USB hubs
+ * @parent_hub : parent hub to scan for connected onboard hubs
+ * @pdev_list : list of onboard hub platform devices owned by the parent hub
+ *
+ * Creates a platform device for each supported onboard hub that is connected to
+ * the given parent hub. The platform device is in charge of initializing the
+ * hub (enable regulators, take the hub out of reset, ...) and can optionally
+ * control whether the hub remains powered during system suspend or not.
+ *
+ * To keep track of the platform devices they are added to a list that is owned
+ * by the parent hub.
+ *
+ * Some background about the logic in this function, which can be a bit hard
+ * to follow:
+ *
+ * Root hubs don't have dedicated device tree nodes, but use the node of their
+ * HCD. The primary and secondary HCD are usually represented by a single DT
+ * node. That means the root hubs of the primary and secondary HCD share the
+ * same device tree node (the HCD node). As a result this function can be called
+ * twice with the same DT node for root hubs. We only want to create a single
+ * platform device for each physical onboard hub, hence for root hubs the loop
+ * is only executed for the root hub of the primary HCD. Since the function
+ * scans through all child nodes it still creates pdevs for onboard hubs
+ * connected to the root hub of the secondary HCD if needed.
+ *
+ * Further there must be only one platform device for onboard hubs with a peer
+ * hub (the hub is a single physical device). To achieve this two measures are
+ * taken: pdevs for onboard hubs with a peer are only created when the function
+ * is called on behalf of the parent hub that is connected to the primary HCD
+ * (directly or through other hubs). For onboard hubs connected to root hubs
+ * the function processes the nodes of both peers. A platform device is only
+ * created if the peer hub doesn't have one already.
+ */
+void onboard_hub_create_pdevs(struct usb_device *parent_hub, struct list_head *pdev_list)
+{
+ int i;
+ struct usb_hcd *hcd = bus_to_hcd(parent_hub->bus);
+ struct device_node *np, *npc;
+ struct platform_device *pdev;
+ struct pdev_list_entry *pdle;
+
+ if (!parent_hub->dev.of_node)
+ return;
+
+ if (!parent_hub->parent && !usb_hcd_is_primary_hcd(hcd))
+ return;
+
+ for (i = 1; i <= parent_hub->maxchild; i++) {
+ np = usb_of_get_device_node(parent_hub, i);
+ if (!np)
+ continue;
+
+ if (!of_is_onboard_usb_hub(np))
+ goto node_put;
+
+ npc = of_parse_phandle(np, "peer-hub", 0);
+ if (npc) {
+ if (!usb_hcd_is_primary_hcd(hcd)) {
+ of_node_put(npc);
+ goto node_put;
+ }
+
+ pdev = of_find_device_by_node(npc);
+ of_node_put(npc);
+
+ if (pdev) {
+ put_device(&pdev->dev);
+ goto node_put;
+ }
+ }
+
+ pdev = of_platform_device_create(np, NULL, &parent_hub->dev);
+ if (!pdev) {
+ dev_err(&parent_hub->dev,
+ "failed to create platform device for onboard hub '%pOF'\n", np);
+ goto node_put;
+ }
+
+ pdle = kzalloc(sizeof(*pdle), GFP_KERNEL);
+ if (!pdle) {
+ of_platform_device_destroy(&pdev->dev, NULL);
+ goto node_put;
+ }
+
+ pdle->pdev = pdev;
+ list_add(&pdle->node, pdev_list);
+
+node_put:
+ of_node_put(np);
+ }
+}
+EXPORT_SYMBOL_GPL(onboard_hub_create_pdevs);
+
+/**
+ * onboard_hub_destroy_pdevs -- free resources of onboard hub platform devices
+ * @pdev_list : list of onboard hub platform devices
+ *
+ * Destroys the platform devices in the given list and frees the memory associated
+ * with the list entry.
+ */
+void onboard_hub_destroy_pdevs(struct list_head *pdev_list)
+{
+ struct pdev_list_entry *pdle, *tmp;
+
+ list_for_each_entry_safe(pdle, tmp, pdev_list, node) {
+ list_del(&pdle->node);
+ of_platform_device_destroy(&pdle->pdev->dev, NULL);
+ kfree(pdle);
+ }
+}
+EXPORT_SYMBOL_GPL(onboard_hub_destroy_pdevs);
diff --git a/include/linux/usb/onboard_hub.h b/include/linux/usb/onboard_hub.h
new file mode 100644
index 000000000000..d9373230556e
--- /dev/null
+++ b/include/linux/usb/onboard_hub.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_USB_ONBOARD_HUB_H
+#define __LINUX_USB_ONBOARD_HUB_H
+
+struct usb_device;
+struct list_head;
+
+#if IS_ENABLED(CONFIG_USB_ONBOARD_HUB)
+void onboard_hub_create_pdevs(struct usb_device *parent_hub, struct list_head *pdev_list);
+void onboard_hub_destroy_pdevs(struct list_head *pdev_list);
+#else
+static inline void onboard_hub_create_pdevs(struct usb_device *parent_hub,
+ struct list_head *pdev_list) {}
+static inline void onboard_hub_destroy_pdevs(struct list_head *pdev_list) {}
+#endif
+
+#endif /* __LINUX_USB_ONBOARD_HUB_H */
--
2.37.0.rc0.161.g10f37bed90-goog
Hi,
On Thu, Jun 30, 2022 at 12:35 PM Matthias Kaehlcke <[email protected]> wrote:
>
> In the context of USB the term 'companion-hub' is misleading, change the
> name of the property to 'peer-hub'.
>
> There are no upstream users of the 'companion-hub' property, neither in
> the device tree, nor on the driver side, so renaming it shouldn't cause
> any compatibility issues with existing device trees.
>
> Changes in v24:
> - patch added to the series
>
> Signed-off-by: Matthias Kaehlcke <[email protected]>
> ---
>
> (no changes since v1)
>
> .../devicetree/bindings/usb/realtek,rts5411.yaml | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
Matches what Alan said...
Reviewed-by: Douglas Anderson <[email protected]>
Hi,
On Thu, Jun 30, 2022 at 12:35 PM Matthias Kaehlcke <[email protected]> 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).
>
> Co-developed-by: Ravi Chandra Sadineni <[email protected]>
> Signed-off-by: Ravi Chandra Sadineni <[email protected]>
> Signed-off-by: Matthias Kaehlcke <[email protected]>
> ---
>
> Changes in v24:
> - changed USB_ONBOARD_HUB from bool to tristate and fixed Makefile
> entry
> - renamed 'companion-hub' property to 'peer-hub'
> - added comment to onboard_hub_create_pdevs() doc that explains the
> somewhat convoluted logic of the function
> - only cancel the driver attach work in onboard_hub_remove() if the
> function wasn't called by the work itself
>
> Changes in v23:
> - refactored onboard_hub_create_pdevs()
> - bail out before the loop for root hubs connected to
> the secondary HCD
> - check for exisiting pdev in the companion hub branch
> instead of doing it afterwards
> - added note about the role of the platform devices to
> documentation of onboard_hub_create_pdevs()
> - got rid of CONFIG_USB_ONBOARD_HUB_ACTUAL, it's not needed anymore
> now that onboard_hub_create/destroy_pdevs() are linked into the USB
> core
> - added some more details to comment about the need to re-attach the
> USB driver
>
> Changes in v22:
> - moved onboard_hub_create_pdevs(), onboard_hub_destroy_pdevs() and
> of_is_onboard_usb_hub() into a separate file to allow them to be
> linked into the USB core module (if CONFIG_USB=m)
> - Added extra checks to ensure only one platform device is created
> for each physical hub. This is necessary because
> onboard_hub_create_pdevs() is now called from hub_probe() instead
> of usb_add_hcd(). As a result the function is called twice for
> typical USB3 hub, once for the USB3 part of the hub, and once for
> USB <= 2.x. Generally the parent hub downstream of the primary HCD
> creates the onboard hub platform device.
> - use kzalloc() instead of devm_kzalloc() to allocate list entries. Using
> managed memory can cause issues since the managed memory is allocated
> before the device is probed.
> - use a workqueue to (re-)attach the USB driver during/after _probe().
> This is necessary to avoid self-deadlocks on systems with nested
> onboard hubs.
> - don't initialize list_head in onboard_hub_create_pdevs(), this needs
> to be done by the owner, to ensure that onboard_hub_destroy_pdevs()
> is called with a struct that was properly initialized even when
> onboard_hub_create_pdevs() is not called.
> - moved 'onboard_hub_match' into an include, so it can be used
> by both the the onboard hub driver and of_is_onboard_usb_hub()
> - removed note from the commit message which said that currently only
> onboard hubs connected to a root hub are supported. This isn't the
> case anymore.
> - updated kernel version and date in sysfs documentation
> - removed tags from Doug and Alan since this version changes quite
> a few things
>
> Changes in v21:
> - refactored _find_onboard_hub()
> - check presence of drvdata instead of using device_is_bound()
> - return -ENODEV if the platform device can't be found
> - always check drvdata, not only when looking for the companion
> hub
> - added comment explaining probe deferral
> - removed 'onboard_hub_dev' symlinks from USB devices
> - updated documentation of 'always_powered_in_suspend' sysfs attribute
>
> Changes in v20:
> - s/nontrivial/non-trivial/ in Kconfig doc
> - added include of 'export.h'
> - initialize variable 'power_off' in onboard_hub_suspend() at
> declaration time
> - renamed set_udev_link_name() to get_udev_link_name()
> - use kzalloc to allocate struct usbdev_node instead of devm_kzalloc()
> - release the lock in onboard_hub_add_usbdev() before calling
> get_udev_link_name()
> - free struct usbdev_node in onboard_hub_remove_usbdev(), now that
> it doesn't used managed memory
> - make struct onboard_hub const in always_powered_in_suspend_show()
> - call put_device() if pdev is not bound in _find_onboard_hub()
> - get driver data before calling put_device() in _find_onboard_hub()
> - log platform device name when sysfs link creation fails in
> onboard_hub_usbdev_probe()
> - added kernel doc for onboard_hub_create_pdevs() and
> onboard_hub_destroy_pdevs()
> - added 'Reviewed-by' tag from Doug
>
> Changes in v19:
> - added VID:PID pairs and compatible strings for RTS5414 hub
> - updated comments with RTS5411 USB versions to reflect those
> reported/supported by the hub
>
> Changes in v18:
> - introduced hidden Kconfig option to align module vs. builtin
> choice with CONFIG_USB (thanks Doug!)
> - refactored onboard_hub_create_pdevs()
>
> Changes in v17:
> - updated date and kernel version in ABI documentation for
> 'always_powered_in_suspend' attribute
> - removed obsolete .yaml entry from MAINTAINERS file
> - added entry for ABI documentation to MAINTAINERS file
> - renamed struct 'udev_node' to 'usbdev_node'
> - changed return logic in onboard_hub_suspend/resume() to
> get rid of 'rc' variable
> - added helper set_udev_link_name() to set link names for
> onboard hub USB devices
> - use of_parse_phandle() instead of of_property_read_u32() +
> of_find_node_by_phandle() combo
> - defer probing in _find_onboard_hub() if the platform device
> isn't bound yet
> - initialize list head passed as parameter to
> onboard_hub_create_pdevs() instead of relying on the caller
> to do so
> - don't require the 'companion-hub' property to be specified.
> This is needed to support hubs without companion hub
> - use devm_kzalloc() to allocate platform device list entries
> and stop freeing them explicitly
> - remove unnecessary INIT_LIST_HEAD() of platform device list
> entries
> - use '%pOF' to print DT node name
> - delete platform device list entries from the list of devices
> in onboard_hub_destroy_pdevs(). It shouldn't be strictly
> necessary, but better be on the safe side.
>
> Changes in v16:
> - none
>
> Changes in v15:
> - none
>
> Changes in v14:
> - none
>
> Changes in v13:
> - none
>
> Changes in v12:
> - use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE) in onboard_hub.h to
> also check for the driver built as module
> - include onboard_hub.h again from the driver to make sure there are
> prototype declarations for the public functions
> - remove indentation from label in onboard_hub_create_pdevs()
>
> Changes in v11:
> - added onboard_hub_create/destroy_pdevs() helpers, to support multiple onboard
> hubs connected to the same parent hub
> - don't include ‘onboard_hub.h’ from the onboard hub driver
> - updated commit message
> - added ‘Acked-by' from Alan
>
> 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/core/Makefile | 4 +
> drivers/usb/misc/Kconfig | 16 +
> drivers/usb/misc/Makefile | 1 +
> drivers/usb/misc/onboard_usb_hub.c | 428 ++++++++++++++++++
> drivers/usb/misc/onboard_usb_hub.h | 17 +
> drivers/usb/misc/onboard_usb_hub_pdevs.c | 142 ++++++
> include/linux/usb/onboard_hub.h | 18 +
> 9 files changed, 641 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 drivers/usb/misc/onboard_usb_hub.h
> create mode 100644 drivers/usb/misc/onboard_usb_hub_pdevs.c
> create mode 100644 include/linux/usb/onboard_hub.h
Reviewed-by: Douglas Anderson <[email protected]>
On Thu, 30 Jun 2022 12:35:28 -0700, Matthias Kaehlcke wrote:
> In the context of USB the term 'companion-hub' is misleading, change the
> name of the property to 'peer-hub'.
>
> There are no upstream users of the 'companion-hub' property, neither in
> the device tree, nor on the driver side, so renaming it shouldn't cause
> any compatibility issues with existing device trees.
>
> Changes in v24:
> - patch added to the series
>
> Signed-off-by: Matthias Kaehlcke <[email protected]>
> ---
>
> (no changes since v1)
>
> .../devicetree/bindings/usb/realtek,rts5411.yaml | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
Acked-by: Rob Herring <[email protected]>