// 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/i2c.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"
/* USB5744 register offset and mask */
#define USB5744_CMD_ATTACH 0xAA
#define USB5744_CMD_ATTACH_LSB 0x56
#define USB5744_CMD_CREG_ACCESS 0x99
#define USB5744_CMD_CREG_ACCESS_LSB 0x37
#define USB5744_CREG_MEM_ADDR 0x00
#define USB5744_CREG_WRITE 0x00
#define USB5744_CREG_RUNTIMEFLAGS2 0x41
#define USB5744_CREG_RUNTIMEFLAGS2_LSB 0x1D
#define USB5744_CREG_BYPASS_UDC_SUSPEND BIT(3)
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);
fsleep(onboard_dev->pdata->power_on_delay_us);
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_5744_i2c_init(struct i2c_client *client)
{
#if IS_ENABLED(CONFIG_I2C)
struct device *dev = &client->dev;
int ret;
/*
* Set BYPASS_UDC_SUSPEND bit to ensure MCU is always enabled
* and ready to respond to SMBus runtime commands.
* The command writes 5 bytes to memory and single data byte in
* configuration register.
*/
char wr_buf[7] = {USB5744_CREG_MEM_ADDR, 5,
USB5744_CREG_WRITE, 1,
USB5744_CREG_RUNTIMEFLAGS2,
USB5744_CREG_RUNTIMEFLAGS2_LSB,
USB5744_CREG_BYPASS_UDC_SUSPEND};
ret = i2c_smbus_write_block_data(client, 0, sizeof(wr_buf), wr_buf);
if (ret)
return dev_err_probe(dev, ret, "BYPASS_UDC_SUSPEND bit configuration failed\n");
ret = i2c_smbus_write_word_data(client, USB5744_CMD_CREG_ACCESS,
USB5744_CMD_CREG_ACCESS_LSB);
if (ret)
return dev_err_probe(dev, ret, "Configuration Register Access Command failed\n");
/* Send SMBus command to boot hub. */
ret = i2c_smbus_write_word_data(client, USB5744_CMD_ATTACH,
USB5744_CMD_ATTACH_LSB);
if (ret < 0)
return dev_err_probe(dev, ret, "USB Attach with SMBus command failed\n");
return ret;
#else
return -ENODEV;
#endif
}
static int onboard_dev_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct onboard_dev *onboard_dev;
struct device_node *i2c_node;
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;
i2c_node = of_parse_phandle(pdev->dev.of_node, "i2c-bus", 0);
if (i2c_node) {
struct i2c_client *client;
client = of_find_i2c_device_by_node(i2c_node);
of_node_put(i2c_node);
if (!client) {
err = -EPROBE_DEFER;
goto err_power_off;
}
if (of_device_is_compatible(pdev->dev.of_node, "usb424,2744") ||
of_device_is_compatible(pdev->dev.of_node, "usb424,5744"))
err = onboard_dev_5744_i2c_init(client);
put_device(&client->dev);
if (err < 0)
goto err_power_off;
}
/*
* 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;
err_power_off:
onboard_dev_power_off(onboard_dev);
return err;
}
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 bool onboard_dev_usbdev_match(struct usb_device *udev)
{
/* Onboard devices using this driver must have a device tree node */
return !!udev->dev.of_node;
}
static int onboard_dev_usbdev_probe(struct usb_device *udev)
{
struct device *dev = &udev->dev;
struct onboard_dev *onboard_dev;
int err;
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",
.match = onboard_dev_usbdev_match,
.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 <[email protected]>");
MODULE_DESCRIPTION("Driver for discrete onboard USB devices");
MODULE_LICENSE("GPL v2");
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