diff options
Diffstat (limited to 'drivers/usb/serial/bus.c')
| -rw-r--r-- | drivers/usb/serial/bus.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/usb/serial/bus.c b/drivers/usb/serial/bus.c new file mode 100644 index 000000000..9e38142ac --- /dev/null +++ b/drivers/usb/serial/bus.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * USB Serial Converter Bus specific functions + * + * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com) + */ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/tty.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/usb.h> +#include <linux/usb/serial.h> + +static int usb_serial_device_match(struct device *dev, + struct device_driver *drv) +{ + const struct usb_serial_port *port = to_usb_serial_port(dev); + struct usb_serial_driver *driver = to_usb_serial_driver(drv); + + /* + * drivers are already assigned to ports in serial_probe so it's + * a simple check here. + */ + if (driver == port->serial->type) + return 1; + + return 0; +} + +static int usb_serial_device_probe(struct device *dev) +{ + struct usb_serial_port *port = to_usb_serial_port(dev); + struct usb_serial_driver *driver; + struct device *tty_dev; + int retval = 0; + int minor; + + /* make sure suspend/resume doesn't race against port_probe */ + retval = usb_autopm_get_interface(port->serial->interface); + if (retval) + return retval; + + driver = port->serial->type; + if (driver->port_probe) { + retval = driver->port_probe(port); + if (retval) + goto err_autopm_put; + } + + minor = port->minor; + tty_dev = tty_port_register_device(&port->port, usb_serial_tty_driver, + minor, dev); + if (IS_ERR(tty_dev)) { + retval = PTR_ERR(tty_dev); + goto err_port_remove; + } + + usb_autopm_put_interface(port->serial->interface); + + dev_info(&port->serial->dev->dev, + "%s converter now attached to ttyUSB%d\n", + driver->description, minor); + + return 0; + +err_port_remove: + if (driver->port_remove) + driver->port_remove(port); +err_autopm_put: + usb_autopm_put_interface(port->serial->interface); + + return retval; +} + +static void usb_serial_device_remove(struct device *dev) +{ + struct usb_serial_port *port = to_usb_serial_port(dev); + struct usb_serial_driver *driver; + int minor; + int autopm_err; + + /* + * Make sure suspend/resume doesn't race against port_remove. + * + * Note that no further runtime PM callbacks will be made if + * autopm_get fails. + */ + autopm_err = usb_autopm_get_interface(port->serial->interface); + + minor = port->minor; + tty_unregister_device(usb_serial_tty_driver, minor); + + driver = port->serial->type; + if (driver->port_remove) + driver->port_remove(port); + + dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", + driver->description, minor); + + if (!autopm_err) + usb_autopm_put_interface(port->serial->interface); +} + +static ssize_t new_id_store(struct device_driver *driver, + const char *buf, size_t count) +{ + struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); + ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, + driver, buf, count); + + if (retval >= 0 && usb_drv->usb_driver != NULL) + retval = usb_store_new_id(&usb_drv->usb_driver->dynids, + usb_drv->usb_driver->id_table, + &usb_drv->usb_driver->drvwrap.driver, + buf, count); + return retval; +} + +static ssize_t new_id_show(struct device_driver *driver, char *buf) +{ + struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); + + return usb_show_dynids(&usb_drv->dynids, buf); +} +static DRIVER_ATTR_RW(new_id); + +static struct attribute *usb_serial_drv_attrs[] = { + &driver_attr_new_id.attr, + NULL, +}; +ATTRIBUTE_GROUPS(usb_serial_drv); + +static void free_dynids(struct usb_serial_driver *drv) +{ + struct usb_dynid *dynid, *n; + + spin_lock(&drv->dynids.lock); + list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { + list_del(&dynid->node); + kfree(dynid); + } + spin_unlock(&drv->dynids.lock); +} + +struct bus_type usb_serial_bus_type = { + .name = "usb-serial", + .match = usb_serial_device_match, + .probe = usb_serial_device_probe, + .remove = usb_serial_device_remove, + .drv_groups = usb_serial_drv_groups, +}; + +int usb_serial_bus_register(struct usb_serial_driver *driver) +{ + int retval; + + driver->driver.bus = &usb_serial_bus_type; + spin_lock_init(&driver->dynids.lock); + INIT_LIST_HEAD(&driver->dynids.list); + + retval = driver_register(&driver->driver); + + return retval; +} + +void usb_serial_bus_deregister(struct usb_serial_driver *driver) +{ + free_dynids(driver); + driver_unregister(&driver->driver); +} + |