serial.h

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * USB Serial Converter stuff
  4 *
  5 *	Copyright (C) 1999 - 2012
  6 *	    Greg Kroah-Hartman (greg@kroah.com)
  7 */
  8
  9#ifndef __LINUX_USB_SERIAL_H
 10#define __LINUX_USB_SERIAL_H
 11
 12#include <linux/kref.h>
 13#include <linux/mutex.h>
 14#include <linux/serial.h>
 15#include <linux/kfifo.h>
 16
 17/* The maximum number of ports one device can grab at once */
 18#define MAX_NUM_PORTS		16
 19
 20/* USB serial flags */
 21#define USB_SERIAL_WRITE_BUSY	0
 22#define USB_SERIAL_THROTTLED	1
 23
 24/**
 25 * usb_serial_port: structure for the specific ports of a device.
 26 * @serial: pointer back to the struct usb_serial owner of this port.
 27 * @port: pointer to the corresponding tty_port for this port.
 28 * @lock: spinlock to grab when updating portions of this structure.
 29 * @minor: the minor number of the port
 30 * @port_number: the struct usb_serial port number of this port (starts at 0)
 31 * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
 32 * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
 33 * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
 34 *	for this port.
 35 * @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
 36 * @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
 37 * @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
 38 * @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
 39 *	for this port.
 40 * @bulk_in_buffer: pointer to the bulk in buffer for this port.
 41 * @bulk_in_size: the size of the bulk_in_buffer, in bytes.
 42 * @read_urb: pointer to the bulk in struct urb for this port.
 43 * @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
 44 *	port.
 45 * @bulk_in_buffers: pointers to the bulk in buffers for this port
 46 * @read_urbs: pointers to the bulk in urbs for this port
 47 * @read_urbs_free: status bitmap the for bulk in urbs
 48 * @bulk_out_buffer: pointer to the bulk out buffer for this port.
 49 * @bulk_out_size: the size of the bulk_out_buffer, in bytes.
 50 * @write_urb: pointer to the bulk out struct urb for this port.
 51 * @write_fifo: kfifo used to buffer outgoing data
 52 * @bulk_out_buffers: pointers to the bulk out buffers for this port
 53 * @write_urbs: pointers to the bulk out urbs for this port
 54 * @write_urbs_free: status bitmap the for bulk out urbs
 55 * @icount: interrupt counters
 56 * @tx_bytes: number of bytes currently in host stack queues
 57 * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
 58 *	port.
 59 * @flags: usb serial port flags
 60 * @work: work queue entry for the line discipline waking up.
 61 * @dev: pointer to the serial device
 62 *
 63 * This structure is used by the usb-serial core and drivers for the specific
 64 * ports of a device.
 65 */
 66struct usb_serial_port {
 67	struct usb_serial	*serial;
 68	struct tty_port		port;
 69	spinlock_t		lock;
 70	u32			minor;
 71	u8			port_number;
 72
 73	unsigned char		*interrupt_in_buffer;
 74	struct urb		*interrupt_in_urb;
 75	__u8			interrupt_in_endpointAddress;
 76
 77	unsigned char		*interrupt_out_buffer;
 78	int			interrupt_out_size;
 79	struct urb		*interrupt_out_urb;
 80	__u8			interrupt_out_endpointAddress;
 81
 82	unsigned char		*bulk_in_buffer;
 83	int			bulk_in_size;
 84	struct urb		*read_urb;
 85	__u8			bulk_in_endpointAddress;
 86
 87	unsigned char		*bulk_in_buffers[2];
 88	struct urb		*read_urbs[2];
 89	unsigned long		read_urbs_free;
 90
 91	unsigned char		*bulk_out_buffer;
 92	int			bulk_out_size;
 93	struct urb		*write_urb;
 94	struct kfifo		write_fifo;
 95
 96	unsigned char		*bulk_out_buffers[2];
 97	struct urb		*write_urbs[2];
 98	unsigned long		write_urbs_free;
 99	__u8			bulk_out_endpointAddress;
100
101	struct async_icount	icount;
102	int			tx_bytes;
103
104	unsigned long		flags;
105	struct work_struct	work;
106	unsigned long		sysrq; /* sysrq timeout */
107	struct device		dev;
108};
109#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
110
111/* get and set the port private data pointer helper functions */
112static inline void *usb_get_serial_port_data(struct usb_serial_port *port)
113{
114	return dev_get_drvdata(&port->dev);
115}
116
117static inline void usb_set_serial_port_data(struct usb_serial_port *port,
118					    void *data)
119{
120	dev_set_drvdata(&port->dev, data);
121}
122
123/**
124 * usb_serial - structure used by the usb-serial core for a device
125 * @dev: pointer to the struct usb_device for this device
126 * @type: pointer to the struct usb_serial_driver for this device
127 * @interface: pointer to the struct usb_interface for this device
128 * @sibling: pointer to the struct usb_interface of any sibling interface
129 * @suspend_count: number of suspended (sibling) interfaces
130 * @num_ports: the number of ports this device has
131 * @num_interrupt_in: number of interrupt in endpoints we have
132 * @num_interrupt_out: number of interrupt out endpoints we have
133 * @num_bulk_in: number of bulk in endpoints we have
134 * @num_bulk_out: number of bulk out endpoints we have
135 * @port: array of struct usb_serial_port structures for the different ports.
136 * @private: place to put any driver specific information that is needed.  The
137 *	usb-serial driver is required to manage this data, the usb-serial core
138 *	will not touch this.  Use usb_get_serial_data() and
139 *	usb_set_serial_data() to access this.
140 */
141struct usb_serial {
142	struct usb_device		*dev;
143	struct usb_serial_driver	*type;
144	struct usb_interface		*interface;
145	struct usb_interface		*sibling;
146	unsigned int			suspend_count;
147	unsigned char			disconnected:1;
148	unsigned char			attached:1;
149	unsigned char			minors_reserved:1;
150	unsigned char			num_ports;
151	unsigned char			num_port_pointers;
152	unsigned char			num_interrupt_in;
153	unsigned char			num_interrupt_out;
154	unsigned char			num_bulk_in;
155	unsigned char			num_bulk_out;
156	struct usb_serial_port		*port[MAX_NUM_PORTS];
157	struct kref			kref;
158	struct mutex			disc_mutex;
159	void				*private;
160};
161#define to_usb_serial(d) container_of(d, struct usb_serial, kref)
162
163/* get and set the serial private data pointer helper functions */
164static inline void *usb_get_serial_data(struct usb_serial *serial)
165{
166	return serial->private;
167}
168
169static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
170{
171	serial->private = data;
172}
173
174struct usb_serial_endpoints {
175	unsigned char num_bulk_in;
176	unsigned char num_bulk_out;
177	unsigned char num_interrupt_in;
178	unsigned char num_interrupt_out;
179	struct usb_endpoint_descriptor *bulk_in[MAX_NUM_PORTS];
180	struct usb_endpoint_descriptor *bulk_out[MAX_NUM_PORTS];
181	struct usb_endpoint_descriptor *interrupt_in[MAX_NUM_PORTS];
182	struct usb_endpoint_descriptor *interrupt_out[MAX_NUM_PORTS];
183};
184
185/**
186 * usb_serial_driver - describes a usb serial driver
187 * @description: pointer to a string that describes this driver.  This string
188 *	used in the syslog messages when a device is inserted or removed.
189 * @id_table: pointer to a list of usb_device_id structures that define all
190 *	of the devices this structure can support.
191 * @num_ports: the number of different ports this device will have.
192 * @num_bulk_in: minimum number of bulk-in endpoints
193 * @num_bulk_out: minimum number of bulk-out endpoints
194 * @num_interrupt_in: minimum number of interrupt-in endpoints
195 * @num_interrupt_out: minimum number of interrupt-out endpoints
196 * @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer
197 *	(0 = end-point size)
198 * @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size)
199 * @calc_num_ports: pointer to a function to determine how many ports this
200 *	device has dynamically. It can also be used to verify the number of
201 *	endpoints or to modify the port-endpoint mapping. It will be called
202 *	after the probe() callback is called, but before attach().
203 * @probe: pointer to the driver's probe function.
204 *	This will be called when the device is inserted into the system,
205 *	but before the device has been fully initialized by the usb_serial
206 *	subsystem.  Use this function to download any firmware to the device,
207 *	or any other early initialization that might be needed.
208 *	Return 0 to continue on with the initialization sequence.  Anything
209 *	else will abort it.
210 * @attach: pointer to the driver's attach function.
211 *	This will be called when the struct usb_serial structure is fully
212 *	set up.  Do any local initialization of the device, or any private
213 *	memory structure allocation at this point in time.
214 * @disconnect: pointer to the driver's disconnect function.  This will be
215 *	called when the device is unplugged or unbound from the driver.
216 * @release: pointer to the driver's release function.  This will be called
217 *	when the usb_serial data structure is about to be destroyed.
218 * @usb_driver: pointer to the struct usb_driver that controls this
219 *	device.  This is necessary to allow dynamic ids to be added to
220 *	the driver from sysfs.
221 *
222 * This structure is defines a USB Serial driver.  It provides all of
223 * the information that the USB serial core code needs.  If the function
224 * pointers are defined, then the USB serial core code will call them when
225 * the corresponding tty port functions are called.  If they are not
226 * called, the generic serial function will be used instead.
227 *
228 * The driver.owner field should be set to the module owner of this driver.
229 * The driver.name field should be set to the name of this driver (remember
230 * it will show up in sysfs, so it needs to be short and to the point.
231 * Using the module name is a good idea.)
232 */
233struct usb_serial_driver {
234	const char *description;
235	const struct usb_device_id *id_table;
236
237	struct list_head	driver_list;
238	struct device_driver	driver;
239	struct usb_driver	*usb_driver;
240	struct usb_dynids	dynids;
241
242	unsigned char		num_ports;
243
244	unsigned char		num_bulk_in;
245	unsigned char		num_bulk_out;
246	unsigned char		num_interrupt_in;
247	unsigned char		num_interrupt_out;
248
249	size_t			bulk_in_size;
250	size_t			bulk_out_size;
251
252	int (*probe)(struct usb_serial *serial, const struct usb_device_id *id);
253	int (*attach)(struct usb_serial *serial);
254	int (*calc_num_ports)(struct usb_serial *serial,
255			struct usb_serial_endpoints *epds);
256
257	void (*disconnect)(struct usb_serial *serial);
258	void (*release)(struct usb_serial *serial);
259
260	int (*port_probe)(struct usb_serial_port *port);
261	void (*port_remove)(struct usb_serial_port *port);
262
263	int (*suspend)(struct usb_serial *serial, pm_message_t message);
264	int (*resume)(struct usb_serial *serial);
265	int (*reset_resume)(struct usb_serial *serial);
266
267	/* serial function calls */
268	/* Called by console and by the tty layer */
269	int  (*open)(struct tty_struct *tty, struct usb_serial_port *port);
270	void (*close)(struct usb_serial_port *port);
271	int  (*write)(struct tty_struct *tty, struct usb_serial_port *port,
272			const unsigned char *buf, int count);
273	/* Called only by the tty layer */
274	unsigned int (*write_room)(struct tty_struct *tty);
275	int  (*ioctl)(struct tty_struct *tty,
276		      unsigned int cmd, unsigned long arg);
277	void (*get_serial)(struct tty_struct *tty, struct serial_struct *ss);
278	int  (*set_serial)(struct tty_struct *tty, struct serial_struct *ss);
279	void (*set_termios)(struct tty_struct *tty, struct usb_serial_port *port,
280			    const struct ktermios *old);
281	int (*break_ctl)(struct tty_struct *tty, int break_state);
282	unsigned int (*chars_in_buffer)(struct tty_struct *tty);
283	void (*wait_until_sent)(struct tty_struct *tty, long timeout);
284	bool (*tx_empty)(struct usb_serial_port *port);
285	void (*throttle)(struct tty_struct *tty);
286	void (*unthrottle)(struct tty_struct *tty);
287	int  (*tiocmget)(struct tty_struct *tty);
288	int  (*tiocmset)(struct tty_struct *tty,
289			 unsigned int set, unsigned int clear);
290	int  (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
291	int  (*get_icount)(struct tty_struct *tty,
292			struct serial_icounter_struct *icount);
293	/* Called by the tty layer for port level work. There may or may not
294	   be an attached tty at this point */
295	void (*dtr_rts)(struct usb_serial_port *port, int on);
296	int  (*carrier_raised)(struct usb_serial_port *port);
297	/* Called by the usb serial hooks to allow the user to rework the
298	   termios state */
299	void (*init_termios)(struct tty_struct *tty);
300	/* USB events */
301	void (*read_int_callback)(struct urb *urb);
302	void (*write_int_callback)(struct urb *urb);
303	void (*read_bulk_callback)(struct urb *urb);
304	void (*write_bulk_callback)(struct urb *urb);
305	/* Called by the generic read bulk callback */
306	void (*process_read_urb)(struct urb *urb);
307	/* Called by the generic write implementation */
308	int (*prepare_write_buffer)(struct usb_serial_port *port,
309						void *dest, size_t size);
310};
311#define to_usb_serial_driver(d) \
312	container_of(d, struct usb_serial_driver, driver)
313
314#define usb_serial_register_drivers(serial_drivers, name, id_table) \
315	__usb_serial_register_drivers(serial_drivers, THIS_MODULE, name, id_table)
316int __usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
317				  struct module *owner, const char *name,
318				  const struct usb_device_id *id_table);
319void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
320void usb_serial_port_softint(struct usb_serial_port *port);
321
322int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
323int usb_serial_resume(struct usb_interface *intf);
324
325/* USB Serial console functions */
326#ifdef CONFIG_USB_SERIAL_CONSOLE
327void usb_serial_console_init(int minor);
328void usb_serial_console_exit(void);
329void usb_serial_console_disconnect(struct usb_serial *serial);
330#else
331static inline void usb_serial_console_init(int minor) { }
332static inline void usb_serial_console_exit(void) { }
333static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
334#endif
335
336/* Functions needed by other parts of the usbserial core */
337struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
338void usb_serial_put(struct usb_serial *serial);
339
340int usb_serial_claim_interface(struct usb_serial *serial, struct usb_interface *intf);
341
342int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port);
343int usb_serial_generic_write_start(struct usb_serial_port *port, gfp_t mem_flags);
344int usb_serial_generic_write(struct tty_struct *tty, struct usb_serial_port *port,
345		const unsigned char *buf, int count);
346void usb_serial_generic_close(struct usb_serial_port *port);
347int usb_serial_generic_resume(struct usb_serial *serial);
348unsigned int usb_serial_generic_write_room(struct tty_struct *tty);
349unsigned int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
350void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout);
351void usb_serial_generic_read_bulk_callback(struct urb *urb);
352void usb_serial_generic_write_bulk_callback(struct urb *urb);
353void usb_serial_generic_throttle(struct tty_struct *tty);
354void usb_serial_generic_unthrottle(struct tty_struct *tty);
355int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg);
356int usb_serial_generic_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount);
357int usb_serial_generic_register(void);
358void usb_serial_generic_deregister(void);
359int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port, gfp_t mem_flags);
360void usb_serial_generic_process_read_urb(struct urb *urb);
361int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port, void *dest, size_t size);
362
363#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
364int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch);
365int usb_serial_handle_break(struct usb_serial_port *port);
366#else
367static inline int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
368{
369	return 0;
370}
371static inline int usb_serial_handle_break(struct usb_serial_port *port)
372{
373	return 0;
374}
375#endif
376
377void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
378		struct tty_struct *tty, unsigned int status);
379
380
381int usb_serial_bus_register(struct usb_serial_driver *device);
382void usb_serial_bus_deregister(struct usb_serial_driver *device);
383
384extern const struct bus_type usb_serial_bus_type;
385extern struct tty_driver *usb_serial_tty_driver;
386
387static inline void usb_serial_debug_data(struct device *dev,
388					 const char *function, int size,
389					 const unsigned char *data)
390{
391	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
392		function, size, size, data);
393}
394
395/*
396 * Macro for reporting errors in write path to avoid infinite loop
397 * when port is used as a console.
398 */
399#define dev_err_console(usport, fmt, ...)				\
400do {									\
401	static bool __print_once;					\
402	struct usb_serial_port *__port = (usport);			\
403									\
404	if (!__port->port.console || !__print_once) {			\
405		__print_once = true;					\
406		dev_err(&__port->dev, fmt, ##__VA_ARGS__);		\
407	}								\
408} while (0)
409
410/*
411 * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
412 * @__serial_drivers: list of usb_serial drivers to register
413 * @__ids: all device ids that @__serial_drivers bind to
414 *
415 * Helper macro for USB serial drivers which do not do anything special
416 * in module init/exit. This eliminates a lot of boilerplate. Each
417 * module may only use this macro once, and calling it replaces
418 * module_init() and module_exit()
419 *
420 */
421#define usb_serial_module_driver(__name, __serial_drivers, __ids)	\
422static int __init usb_serial_module_init(void)				\
423{									\
424	return usb_serial_register_drivers(__serial_drivers,		\
425					   __name, __ids);		\
426}									\
427module_init(usb_serial_module_init);					\
428static void __exit usb_serial_module_exit(void)				\
429{									\
430	usb_serial_deregister_drivers(__serial_drivers);		\
431}									\
432module_exit(usb_serial_module_exit);
433
434#define module_usb_serial_driver(__serial_drivers, __ids)		\
435	usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
436
437#endif /* __LINUX_USB_SERIAL_H */
438