1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * USB Serial Converter Bus specific functions |
4 | * |
5 | * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com) |
6 | */ |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/errno.h> |
10 | #include <linux/tty.h> |
11 | #include <linux/slab.h> |
12 | #include <linux/module.h> |
13 | #include <linux/usb.h> |
14 | #include <linux/usb/serial.h> |
15 | |
16 | static int usb_serial_device_match(struct device *dev, |
17 | struct device_driver *drv) |
18 | { |
19 | const struct usb_serial_port *port = to_usb_serial_port(dev); |
20 | struct usb_serial_driver *driver = to_usb_serial_driver(drv); |
21 | |
22 | /* |
23 | * drivers are already assigned to ports in serial_probe so it's |
24 | * a simple check here. |
25 | */ |
26 | if (driver == port->serial->type) |
27 | return 1; |
28 | |
29 | return 0; |
30 | } |
31 | |
32 | static int usb_serial_device_probe(struct device *dev) |
33 | { |
34 | struct usb_serial_port *port = to_usb_serial_port(dev); |
35 | struct usb_serial_driver *driver; |
36 | struct device *tty_dev; |
37 | int retval = 0; |
38 | int minor; |
39 | |
40 | /* make sure suspend/resume doesn't race against port_probe */ |
41 | retval = usb_autopm_get_interface(intf: port->serial->interface); |
42 | if (retval) |
43 | return retval; |
44 | |
45 | driver = port->serial->type; |
46 | if (driver->port_probe) { |
47 | retval = driver->port_probe(port); |
48 | if (retval) |
49 | goto err_autopm_put; |
50 | } |
51 | |
52 | minor = port->minor; |
53 | tty_dev = tty_port_register_device(port: &port->port, driver: usb_serial_tty_driver, |
54 | index: minor, device: dev); |
55 | if (IS_ERR(ptr: tty_dev)) { |
56 | retval = PTR_ERR(ptr: tty_dev); |
57 | goto err_port_remove; |
58 | } |
59 | |
60 | usb_autopm_put_interface(intf: port->serial->interface); |
61 | |
62 | dev_info(&port->serial->dev->dev, |
63 | "%s converter now attached to ttyUSB%d\n" , |
64 | driver->description, minor); |
65 | |
66 | return 0; |
67 | |
68 | err_port_remove: |
69 | if (driver->port_remove) |
70 | driver->port_remove(port); |
71 | err_autopm_put: |
72 | usb_autopm_put_interface(intf: port->serial->interface); |
73 | |
74 | return retval; |
75 | } |
76 | |
77 | static void usb_serial_device_remove(struct device *dev) |
78 | { |
79 | struct usb_serial_port *port = to_usb_serial_port(dev); |
80 | struct usb_serial_driver *driver; |
81 | int minor; |
82 | int autopm_err; |
83 | |
84 | /* |
85 | * Make sure suspend/resume doesn't race against port_remove. |
86 | * |
87 | * Note that no further runtime PM callbacks will be made if |
88 | * autopm_get fails. |
89 | */ |
90 | autopm_err = usb_autopm_get_interface(intf: port->serial->interface); |
91 | |
92 | minor = port->minor; |
93 | tty_unregister_device(driver: usb_serial_tty_driver, index: minor); |
94 | |
95 | driver = port->serial->type; |
96 | if (driver->port_remove) |
97 | driver->port_remove(port); |
98 | |
99 | dev_info(dev, "%s converter now disconnected from ttyUSB%d\n" , |
100 | driver->description, minor); |
101 | |
102 | if (!autopm_err) |
103 | usb_autopm_put_interface(intf: port->serial->interface); |
104 | } |
105 | |
106 | static ssize_t new_id_store(struct device_driver *driver, |
107 | const char *buf, size_t count) |
108 | { |
109 | struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); |
110 | ssize_t retval = usb_store_new_id(dynids: &usb_drv->dynids, id_table: usb_drv->id_table, |
111 | driver, buf, count); |
112 | |
113 | if (retval >= 0 && usb_drv->usb_driver != NULL) |
114 | retval = usb_store_new_id(dynids: &usb_drv->usb_driver->dynids, |
115 | id_table: usb_drv->usb_driver->id_table, |
116 | driver: &usb_drv->usb_driver->drvwrap.driver, |
117 | buf, count); |
118 | return retval; |
119 | } |
120 | |
121 | static ssize_t new_id_show(struct device_driver *driver, char *buf) |
122 | { |
123 | struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); |
124 | |
125 | return usb_show_dynids(dynids: &usb_drv->dynids, buf); |
126 | } |
127 | static DRIVER_ATTR_RW(new_id); |
128 | |
129 | static struct attribute *usb_serial_drv_attrs[] = { |
130 | &driver_attr_new_id.attr, |
131 | NULL, |
132 | }; |
133 | ATTRIBUTE_GROUPS(usb_serial_drv); |
134 | |
135 | static void free_dynids(struct usb_serial_driver *drv) |
136 | { |
137 | struct usb_dynid *dynid, *n; |
138 | |
139 | spin_lock(lock: &drv->dynids.lock); |
140 | list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { |
141 | list_del(entry: &dynid->node); |
142 | kfree(objp: dynid); |
143 | } |
144 | spin_unlock(lock: &drv->dynids.lock); |
145 | } |
146 | |
147 | const struct bus_type usb_serial_bus_type = { |
148 | .name = "usb-serial" , |
149 | .match = usb_serial_device_match, |
150 | .probe = usb_serial_device_probe, |
151 | .remove = usb_serial_device_remove, |
152 | .drv_groups = usb_serial_drv_groups, |
153 | }; |
154 | |
155 | int usb_serial_bus_register(struct usb_serial_driver *driver) |
156 | { |
157 | int retval; |
158 | |
159 | driver->driver.bus = &usb_serial_bus_type; |
160 | spin_lock_init(&driver->dynids.lock); |
161 | INIT_LIST_HEAD(list: &driver->dynids.list); |
162 | |
163 | retval = driver_register(drv: &driver->driver); |
164 | |
165 | return retval; |
166 | } |
167 | |
168 | void usb_serial_bus_deregister(struct usb_serial_driver *driver) |
169 | { |
170 | free_dynids(drv: driver); |
171 | driver_unregister(drv: &driver->driver); |
172 | } |
173 | |
174 | |