On 20-09-17 11:46:22, Matthias Kaehlcke wrote:
> The main issue this driver addresses is that a USB hub needs to be
> powered before it can be discovered. For onboard hubs 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 further 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 <ravisadineni@xxxxxxxxxxxx>
> Signed-off-by: Ravi Chandra Sadineni <ravisadineni@xxxxxxxxxxxx>
> Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> ---
>
> 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
>
> drivers/usb/misc/Kconfig | 15 ++
> drivers/usb/misc/Makefile | 1 +
> drivers/usb/misc/onboard_usb_hub.c | 329 +++++++++++++++++++++++++++++
> 3 files changed, 345 insertions(+)
> create mode 100644 drivers/usb/misc/onboard_usb_hub.c
>
> diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
> index 6818ea689cd9..e941244e24e5 100644
> --- a/drivers/usb/misc/Kconfig
> +++ b/drivers/usb/misc/Kconfig
> @@ -275,3 +275,18 @@ config USB_CHAOSKEY
>
> To compile this driver as a module, choose M here: the
> module will be called chaoskey.
> +
> +config USB_ONBOARD_HUB
> + tristate "Onboard USB hub support"
On board HUB belongs to HUB, this driver is just for possible power and
initialization requirements for HUB which is hard-wired on board. The
configuration name USB_HUB_POWER_SUPPLY may more suitable, and at the
menu and help, you could indicate it is special for HUBs which are
hard-wired on board.
> +static ssize_t power_off_in_suspend_show(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct onboard_hub *hub = dev_get_drvdata(dev);
> +
> + return sprintf(buf, "%d\n", hub->power_off_in_suspend);
> +}
> +
> +static ssize_t power_off_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 = strtobool(buf, &val);
> + if (ret < 0)
> + return ret;
> +
> + hub->power_off_in_suspend = val;
> +
> + return count;
> +}
> +static DEVICE_ATTR_RW(power_off_in_suspend);
> +
> +static int onboard_hub_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct onboard_hub *hub;
> + int rc;
> +
> + 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);
> +
> + rc = sysfs_create_file(&dev->kobj, &dev_attr_power_off_in_suspend.attr);
> + if (rc)
> + return rc;
You could use dev_groups for sysfs entry management.
> +/************************** USB driver **************************/
> +
> +#define VENDOR_ID_REALTEK 0x0bda
> +
> +static struct onboard_hub *_find_onboard_hub(struct device *dev)
> +{
> + const phandle *ph;
> + struct device_node *np;
> + struct platform_device *pdev;
> +
> + ph = of_get_property(dev->of_node, "hub", NULL);
> + if (!ph) {
> + dev_err(dev, "failed to read 'hub' property\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> + np = of_find_node_by_phandle(be32_to_cpu(*ph));
> + if (!np) {
> + dev_err(dev, "failed find device node for onboard hub\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> + pdev = of_find_device_by_node(np);
> + of_node_put(np);
> + if (!pdev)
> + return ERR_PTR(-EPROBE_DEFER);
> +
> + 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;
> +
> + /* 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(dev);
> +
> + dev_set_drvdata(dev, hub);
> +
> + onboard_hub_add_usbdev(hub, udev);
> +
> + 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);
> +
> + put_device(hub->dev);
> +}
> +
> +static const struct usb_device_id onboard_hub_id_table[] = {
> + { .idVendor = VENDOR_ID_REALTEK,
> + .idProduct = 0x0411, /* RTS5411 USB 3.0 */
> + .match_flags = USB_DEVICE_ID_MATCH_DEVICE },
> + { .idVendor = VENDOR_ID_REALTEK,
> + .idProduct = 0x5411, /* RTS5411 USB 2.0 */
> + .match_flags = USB_DEVICE_ID_MATCH_DEVICE },
> + {},
> +};
> +
> +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 rc;
> +
> + rc = platform_driver_register(&onboard_hub_driver);
> + if (rc)
> + return rc;
> +
> + return usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE);
> +}
> +device_initcall(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@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Onboard USB Hub driver");
Improve the description like mentioned above.
--
Thanks,
Peter Chen
