diff options
Diffstat (limited to 'drivers/usb/misc/onboard_usb_dev.c')
| -rw-r--r-- | drivers/usb/misc/onboard_usb_dev.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/drivers/usb/misc/onboard_usb_dev.c b/drivers/usb/misc/onboard_usb_dev.c new file mode 100644 index 0000000000..f2bcc1a8b9 --- /dev/null +++ b/drivers/usb/misc/onboard_usb_dev.c @@ -0,0 +1,550 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for onboard USB devices + * + * Copyright (c) 2022, Google LLC + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/export.h> +#include <linux/err.h> +#include <linux/gpio/consumer.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_dev.h> +#include <linux/workqueue.h> + +#include "onboard_usb_dev.h" + +static void onboard_dev_attach_usb_driver(struct work_struct *work); + +static struct usb_device_driver onboard_dev_usbdev_driver; +static DECLARE_WORK(attach_usb_driver_work, onboard_dev_attach_usb_driver); + +/************************** Platform driver **************************/ + +struct usbdev_node { + struct usb_device *udev; + struct list_head list; +}; + +struct onboard_dev { + struct regulator_bulk_data supplies[MAX_SUPPLIES]; + struct device *dev; + const struct onboard_dev_pdata *pdata; + struct gpio_desc *reset_gpio; + bool always_powered_in_suspend; + bool is_powered_on; + bool going_away; + struct list_head udev_list; + struct mutex lock; + struct clk *clk; +}; + +static int onboard_dev_get_regulators(struct onboard_dev *onboard_dev) +{ + const char * const *supply_names = onboard_dev->pdata->supply_names; + unsigned int num_supplies = onboard_dev->pdata->num_supplies; + struct device *dev = onboard_dev->dev; + unsigned int i; + int err; + + if (num_supplies > MAX_SUPPLIES) + return dev_err_probe(dev, -EINVAL, "max %d supplies supported!\n", + MAX_SUPPLIES); + + for (i = 0; i < num_supplies; i++) + onboard_dev->supplies[i].supply = supply_names[i]; + + err = devm_regulator_bulk_get(dev, num_supplies, onboard_dev->supplies); + if (err) + dev_err(dev, "Failed to get regulator supplies: %pe\n", + ERR_PTR(err)); + + return err; +} + +static int onboard_dev_power_on(struct onboard_dev *onboard_dev) +{ + int err; + + err = clk_prepare_enable(onboard_dev->clk); + if (err) { + dev_err(onboard_dev->dev, "failed to enable clock: %pe\n", + ERR_PTR(err)); + return err; + } + + err = regulator_bulk_enable(onboard_dev->pdata->num_supplies, + onboard_dev->supplies); + if (err) { + dev_err(onboard_dev->dev, "failed to enable supplies: %pe\n", + ERR_PTR(err)); + goto disable_clk; + } + + fsleep(onboard_dev->pdata->reset_us); + gpiod_set_value_cansleep(onboard_dev->reset_gpio, 0); + + onboard_dev->is_powered_on = true; + + return 0; + +disable_clk: + clk_disable_unprepare(onboard_dev->clk); + return err; +} + +static int onboard_dev_power_off(struct onboard_dev *onboard_dev) +{ + int err; + + gpiod_set_value_cansleep(onboard_dev->reset_gpio, 1); + + err = regulator_bulk_disable(onboard_dev->pdata->num_supplies, + onboard_dev->supplies); + if (err) { + dev_err(onboard_dev->dev, "failed to disable supplies: %pe\n", + ERR_PTR(err)); + return err; + } + + clk_disable_unprepare(onboard_dev->clk); + + onboard_dev->is_powered_on = false; + + return 0; +} + +static int __maybe_unused onboard_dev_suspend(struct device *dev) +{ + struct onboard_dev *onboard_dev = dev_get_drvdata(dev); + struct usbdev_node *node; + bool power_off = true; + + if (onboard_dev->always_powered_in_suspend) + return 0; + + mutex_lock(&onboard_dev->lock); + + list_for_each_entry(node, &onboard_dev->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(&onboard_dev->lock); + + if (!power_off) + return 0; + + return onboard_dev_power_off(onboard_dev); +} + +static int __maybe_unused onboard_dev_resume(struct device *dev) +{ + struct onboard_dev *onboard_dev = dev_get_drvdata(dev); + + if (onboard_dev->is_powered_on) + return 0; + + return onboard_dev_power_on(onboard_dev); +} + +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_dev_add_usbdev(struct onboard_dev *onboard_dev, + struct usb_device *udev) +{ + struct usbdev_node *node; + char link_name[64]; + int err; + + mutex_lock(&onboard_dev->lock); + + if (onboard_dev->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, &onboard_dev->udev_list); + + mutex_unlock(&onboard_dev->lock); + + get_udev_link_name(udev, link_name, sizeof(link_name)); + WARN_ON(sysfs_create_link(&onboard_dev->dev->kobj, &udev->dev.kobj, + link_name)); + + return 0; + +error: + mutex_unlock(&onboard_dev->lock); + + return err; +} + +static void onboard_dev_remove_usbdev(struct onboard_dev *onboard_dev, + 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(&onboard_dev->dev->kobj, link_name); + + mutex_lock(&onboard_dev->lock); + + list_for_each_entry(node, &onboard_dev->udev_list, list) { + if (node->udev == udev) { + list_del(&node->list); + kfree(node); + break; + } + } + + mutex_unlock(&onboard_dev->lock); +} + +static ssize_t always_powered_in_suspend_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + const struct onboard_dev *onboard_dev = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%d\n", onboard_dev->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_dev *onboard_dev = dev_get_drvdata(dev); + bool val; + int ret; + + ret = kstrtobool(buf, &val); + if (ret < 0) + return ret; + + onboard_dev->always_powered_in_suspend = val; + + return count; +} +static DEVICE_ATTR_RW(always_powered_in_suspend); + +static struct attribute *onboard_dev_attrs[] = { + &dev_attr_always_powered_in_suspend.attr, + NULL, +}; + +static umode_t onboard_dev_attrs_are_visible(struct kobject *kobj, + struct attribute *attr, + int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct onboard_dev *onboard_dev = dev_get_drvdata(dev); + + if (attr == &dev_attr_always_powered_in_suspend.attr && + !onboard_dev->pdata->is_hub) + return 0; + + return attr->mode; +} + +static const struct attribute_group onboard_dev_group = { + .is_visible = onboard_dev_attrs_are_visible, + .attrs = onboard_dev_attrs, +}; +__ATTRIBUTE_GROUPS(onboard_dev); + + +static void onboard_dev_attach_usb_driver(struct work_struct *work) +{ + int err; + + err = driver_attach(&onboard_dev_usbdev_driver.driver); + if (err) + pr_err("Failed to attach USB driver: %pe\n", ERR_PTR(err)); +} + +static int onboard_dev_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct onboard_dev *onboard_dev; + int err; + + onboard_dev = devm_kzalloc(dev, sizeof(*onboard_dev), GFP_KERNEL); + if (!onboard_dev) + return -ENOMEM; + + onboard_dev->pdata = device_get_match_data(dev); + if (!onboard_dev->pdata) + return -EINVAL; + + if (!onboard_dev->pdata->is_hub) + onboard_dev->always_powered_in_suspend = true; + + onboard_dev->dev = dev; + + err = onboard_dev_get_regulators(onboard_dev); + if (err) + return err; + + onboard_dev->clk = devm_clk_get_optional(dev, NULL); + if (IS_ERR(onboard_dev->clk)) + return dev_err_probe(dev, PTR_ERR(onboard_dev->clk), + "failed to get clock\n"); + + onboard_dev->reset_gpio = devm_gpiod_get_optional(dev, "reset", + GPIOD_OUT_HIGH); + if (IS_ERR(onboard_dev->reset_gpio)) + return dev_err_probe(dev, PTR_ERR(onboard_dev->reset_gpio), + "failed to get reset GPIO\n"); + + mutex_init(&onboard_dev->lock); + INIT_LIST_HEAD(&onboard_dev->udev_list); + + dev_set_drvdata(dev, onboard_dev); + + err = onboard_dev_power_on(onboard_dev); + if (err) + return err; + + /* + * The USB driver might have been detached from the USB devices by + * onboard_dev_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. + */ + schedule_work(&attach_usb_driver_work); + + return 0; +} + +static void onboard_dev_remove(struct platform_device *pdev) +{ + struct onboard_dev *onboard_dev = dev_get_drvdata(&pdev->dev); + struct usbdev_node *node; + struct usb_device *udev; + + onboard_dev->going_away = true; + + mutex_lock(&onboard_dev->lock); + + /* unbind the USB devices to avoid dangling references to this device */ + while (!list_empty(&onboard_dev->udev_list)) { + node = list_first_entry(&onboard_dev->udev_list, + struct usbdev_node, list); + udev = node->udev; + + /* + * Unbinding the driver will call onboard_dev_remove_usbdev(), + * which acquires onboard_dev->lock. We must release the lock + * first. + */ + get_device(&udev->dev); + mutex_unlock(&onboard_dev->lock); + device_release_driver(&udev->dev); + put_device(&udev->dev); + mutex_lock(&onboard_dev->lock); + } + + mutex_unlock(&onboard_dev->lock); + + onboard_dev_power_off(onboard_dev); +} + +MODULE_DEVICE_TABLE(of, onboard_dev_match); + +static const struct dev_pm_ops __maybe_unused onboard_dev_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_dev_suspend, onboard_dev_resume) +}; + +static struct platform_driver onboard_dev_driver = { + .probe = onboard_dev_probe, + .remove_new = onboard_dev_remove, + + .driver = { + .name = "onboard-usb-dev", + .of_match_table = onboard_dev_match, + .pm = pm_ptr(&onboard_dev_pm_ops), + .dev_groups = onboard_dev_groups, + }, +}; + +/************************** USB driver **************************/ + +#define VENDOR_ID_CYPRESS 0x04b4 +#define VENDOR_ID_GENESYS 0x05e3 +#define VENDOR_ID_MICROCHIP 0x0424 +#define VENDOR_ID_REALTEK 0x0bda +#define VENDOR_ID_TI 0x0451 +#define VENDOR_ID_VIA 0x2109 +#define VENDOR_ID_XMOS 0x20B1 + +/* + * Returns the onboard_dev platform device that is associated with the USB + * device passed as parameter. + */ +static struct onboard_dev *_find_onboard_dev(struct device *dev) +{ + struct platform_device *pdev; + struct device_node *np; + struct onboard_dev *onboard_dev; + + 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); + } + + onboard_dev = dev_get_drvdata(&pdev->dev); + put_device(&pdev->dev); + + /* + * The presence of drvdata 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 (!onboard_dev) + return ERR_PTR(-EPROBE_DEFER); + + return onboard_dev; +} + +static int onboard_dev_usbdev_probe(struct usb_device *udev) +{ + struct device *dev = &udev->dev; + struct onboard_dev *onboard_dev; + int err; + + /* ignore supported devices without device tree node */ + if (!dev->of_node) + return -ENODEV; + + onboard_dev = _find_onboard_dev(dev); + if (IS_ERR(onboard_dev)) + return PTR_ERR(onboard_dev); + + dev_set_drvdata(dev, onboard_dev); + + err = onboard_dev_add_usbdev(onboard_dev, udev); + if (err) + return err; + + return 0; +} + +static void onboard_dev_usbdev_disconnect(struct usb_device *udev) +{ + struct onboard_dev *onboard_dev = dev_get_drvdata(&udev->dev); + + onboard_dev_remove_usbdev(onboard_dev, udev); +} + +static const struct usb_device_id onboard_dev_id_table[] = { + { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6504) }, /* CYUSB33{0,1,2}x/CYUSB230x 3.0 HUB */ + { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB33{0,1,2}x/CYUSB230x 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6570) }, /* CY7C6563x 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 HUB */ + { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 HUB */ + { USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.1 HUB */ + { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 HUB */ + { USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 HUB */ + { USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 HUB */ + { USB_DEVICE(VENDOR_ID_TI, 0x8025) }, /* TI USB8020B 3.0 HUB */ + { USB_DEVICE(VENDOR_ID_TI, 0x8027) }, /* TI USB8020B 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 HUB */ + { USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 HUB */ + { USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 2.0 HUB */ + { USB_DEVICE(VENDOR_ID_XMOS, 0x0013) }, /* XMOS XVF3500 Voice Processor */ + {} +}; +MODULE_DEVICE_TABLE(usb, onboard_dev_id_table); + +static struct usb_device_driver onboard_dev_usbdev_driver = { + .name = "onboard-usb-dev", + .probe = onboard_dev_usbdev_probe, + .disconnect = onboard_dev_usbdev_disconnect, + .generic_subclass = 1, + .supports_autosuspend = 1, + .id_table = onboard_dev_id_table, +}; + +static int __init onboard_dev_init(void) +{ + int ret; + + ret = usb_register_device_driver(&onboard_dev_usbdev_driver, THIS_MODULE); + if (ret) + return ret; + + ret = platform_driver_register(&onboard_dev_driver); + if (ret) + usb_deregister_device_driver(&onboard_dev_usbdev_driver); + + return ret; +} +module_init(onboard_dev_init); + +static void __exit onboard_dev_exit(void) +{ + usb_deregister_device_driver(&onboard_dev_usbdev_driver); + platform_driver_unregister(&onboard_dev_driver); + + cancel_work_sync(&attach_usb_driver_work); +} +module_exit(onboard_dev_exit); + +MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>"); +MODULE_DESCRIPTION("Driver for discrete onboard USB devices"); +MODULE_LICENSE("GPL v2"); |