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linux-stable/drivers/usb/misc/onboard_usb_hub.c
Frieder Schrempf 24af68a0ed usb: misc: onboard_usb_hub: Add support for Cypress CY7C6563x 
The Cypress CY7C6563x is a 2/4-port USB 2.0 hub. Add support for
this hub in the driver in order to bring up reset, supply or clock
dependencies.

There is no reset pulse width given in the datasheet so we expect
a minimal value of 1us to be enough. This hasn't been tested though
due to lack of hardware which has the reset connected to a GPIO.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Link: https://lore.kernel.org/r/20231127112234.109073-3-frieder@fris.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-27 19:13:22 +00:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for onboard USB hubs
*
* 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_hub.h>
#include <linux/workqueue.h>
#include "onboard_usb_hub.h"
/*
* Use generic names, as the actual names might differ between hubs. If a new
* hub requires more than the currently supported supplies, add a new one here.
*/
static const char * const supply_names[] = {
"vdd",
"vdd2",
};
#define MAX_SUPPLIES ARRAY_SIZE(supply_names)
static void onboard_hub_attach_usb_driver(struct work_struct *work);
static struct usb_device_driver onboard_hub_usbdev_driver;
static DECLARE_WORK(attach_usb_driver_work, onboard_hub_attach_usb_driver);
/************************** Platform driver **************************/
struct usbdev_node {
struct usb_device *udev;
struct list_head list;
};
struct onboard_hub {
struct regulator_bulk_data supplies[MAX_SUPPLIES];
struct device *dev;
const struct onboard_hub_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_hub_power_on(struct onboard_hub *hub)
{
int err;
err = clk_prepare_enable(hub->clk);
if (err) {
dev_err(hub->dev, "failed to enable clock: %pe\n", ERR_PTR(err));
return err;
}
err = regulator_bulk_enable(hub->pdata->num_supplies, hub->supplies);
if (err) {
dev_err(hub->dev, "failed to enable supplies: %pe\n", ERR_PTR(err));
return err;
}
fsleep(hub->pdata->reset_us);
gpiod_set_value_cansleep(hub->reset_gpio, 0);
hub->is_powered_on = true;
return 0;
}
static int onboard_hub_power_off(struct onboard_hub *hub)
{
int err;
gpiod_set_value_cansleep(hub->reset_gpio, 1);
err = regulator_bulk_disable(hub->pdata->num_supplies, hub->supplies);
if (err) {
dev_err(hub->dev, "failed to disable supplies: %pe\n", ERR_PTR(err));
return err;
}
clk_disable_unprepare(hub->clk);
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: %pe\n", ERR_PTR(err));
}
static int onboard_hub_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct onboard_hub *hub;
unsigned int i;
int err;
hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL);
if (!hub)
return -ENOMEM;
hub->pdata = device_get_match_data(&pdev->dev);
if (!hub->pdata)
return -EINVAL;
if (hub->pdata->num_supplies > MAX_SUPPLIES)
return dev_err_probe(dev, -EINVAL, "max %zu supplies supported!\n",
MAX_SUPPLIES);
for (i = 0; i < hub->pdata->num_supplies; i++)
hub->supplies[i].supply = supply_names[i];
err = devm_regulator_bulk_get(dev, hub->pdata->num_supplies, hub->supplies);
if (err) {
dev_err(dev, "Failed to get regulator supplies: %pe\n", ERR_PTR(err));
return err;
}
hub->clk = devm_clk_get_optional(dev, NULL);
if (IS_ERR(hub->clk))
return dev_err_probe(dev, PTR_ERR(hub->clk), "failed to get clock\n");
hub->reset_gpio = devm_gpiod_get_optional(dev, "reset",
GPIOD_OUT_HIGH);
if (IS_ERR(hub->reset_gpio))
return dev_err_probe(dev, PTR_ERR(hub->reset_gpio), "failed to get reset GPIO\n");
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.
*/
schedule_work(&attach_usb_driver_work);
return 0;
}
static void 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;
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);
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_new = 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_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
/*
* 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_CYPRESS, 0x6504) }, /* CYUSB33{0,1,2}x/CYUSB230x 3.0 */
{ USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB33{0,1,2}x/CYUSB230x 2.0 */
{ USB_DEVICE(VENDOR_ID_CYPRESS, 0x6570) }, /* CY7C6563x 2.0 */
{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 */
{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 */
{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 */
{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 */
{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 */
{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 */
{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 */
{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 */
{ 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 */
{ USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 */
{ USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 */
{ USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 */
{ USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 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,
};
static int __init onboard_hub_init(void)
{
int ret;
ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE);
if (ret)
return ret;
ret = platform_driver_register(&onboard_hub_driver);
if (ret)
usb_deregister_device_driver(&onboard_hub_usbdev_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);
cancel_work_sync(&attach_usb_driver_work);
}
module_exit(onboard_hub_exit);
MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
MODULE_DESCRIPTION("Driver for discrete onboard USB hubs");
MODULE_LICENSE("GPL v2");
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