xref: /openbmc/linux/drivers/usb/serial/metro-usb.c (revision 95c96174)
1 /*
2   Some of this code is credited to Linux USB open source files that are
3   distributed with Linux.
4 
5   Copyright:	2007 Metrologic Instruments. All rights reserved.
6   Copyright:	2011 Azimut Ltd. <http://azimutrzn.ru/>
7 */
8 
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/tty.h>
12 #include <linux/module.h>
13 #include <linux/usb.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/tty_driver.h>
17 #include <linux/tty_flip.h>
18 #include <linux/moduleparam.h>
19 #include <linux/spinlock.h>
20 #include <linux/errno.h>
21 #include <linux/uaccess.h>
22 #include <linux/usb/serial.h>
23 
24 /* Version Information */
25 #define DRIVER_VERSION "v1.2.0.0"
26 #define DRIVER_DESC "Metrologic Instruments Inc. - USB-POS driver"
27 
28 /* Product information. */
29 #define FOCUS_VENDOR_ID			0x0C2E
30 #define FOCUS_PRODUCT_ID		0x0720
31 #define FOCUS_PRODUCT_ID_UNI		0x0710
32 
33 #define METROUSB_SET_REQUEST_TYPE	0x40
34 #define METROUSB_SET_MODEM_CTRL_REQUEST	10
35 #define METROUSB_SET_BREAK_REQUEST	0x40
36 #define METROUSB_MCR_NONE		0x08	/* Deactivate DTR and RTS. */
37 #define METROUSB_MCR_RTS		0x0a	/* Activate RTS. */
38 #define METROUSB_MCR_DTR		0x09	/* Activate DTR. */
39 #define WDR_TIMEOUT			5000	/* default urb timeout. */
40 
41 /* Private data structure. */
42 struct metrousb_private {
43 	spinlock_t lock;
44 	int throttled;
45 	unsigned long control_state;
46 };
47 
48 /* Device table list. */
49 static struct usb_device_id id_table[] = {
50 	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID) },
51 	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_UNI) },
52 	{ }, /* Terminating entry. */
53 };
54 MODULE_DEVICE_TABLE(usb, id_table);
55 
56 /* Input parameter constants. */
57 static bool debug;
58 
59 static void metrousb_read_int_callback(struct urb *urb)
60 {
61 	struct usb_serial_port *port = urb->context;
62 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
63 	struct tty_struct *tty;
64 	unsigned char *data = urb->transfer_buffer;
65 	int throttled = 0;
66 	int result = 0;
67 	unsigned long flags = 0;
68 
69 	dev_dbg(&port->dev, "%s\n", __func__);
70 
71 	switch (urb->status) {
72 	case 0:
73 		/* Success status, read from the port. */
74 		break;
75 	case -ECONNRESET:
76 	case -ENOENT:
77 	case -ESHUTDOWN:
78 		/* urb has been terminated. */
79 		dev_dbg(&port->dev,
80 			"%s - urb shutting down, error code=%d\n",
81 			__func__, result);
82 		return;
83 	default:
84 		dev_dbg(&port->dev,
85 			"%s - non-zero urb received, error code=%d\n",
86 			__func__, result);
87 		goto exit;
88 	}
89 
90 
91 	/* Set the data read from the usb port into the serial port buffer. */
92 	tty = tty_port_tty_get(&port->port);
93 	if (!tty) {
94 		dev_dbg(&port->dev, "%s - bad tty pointer - exiting\n",
95 			__func__);
96 		return;
97 	}
98 
99 	if (tty && urb->actual_length) {
100 		/* Loop through the data copying each byte to the tty layer. */
101 		tty_insert_flip_string(tty, data, urb->actual_length);
102 
103 		/* Force the data to the tty layer. */
104 		tty_flip_buffer_push(tty);
105 	}
106 	tty_kref_put(tty);
107 
108 	/* Set any port variables. */
109 	spin_lock_irqsave(&metro_priv->lock, flags);
110 	throttled = metro_priv->throttled;
111 	spin_unlock_irqrestore(&metro_priv->lock, flags);
112 
113 	/* Continue trying to read if set. */
114 	if (!throttled) {
115 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
116 				 usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
117 				 port->interrupt_in_urb->transfer_buffer,
118 				 port->interrupt_in_urb->transfer_buffer_length,
119 				 metrousb_read_int_callback, port, 1);
120 
121 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
122 
123 		if (result)
124 			dev_dbg(&port->dev,
125 				"%s - failed submitting interrupt in urb, error code=%d\n",
126 				__func__, result);
127 	}
128 	return;
129 
130 exit:
131 	/* Try to resubmit the urb. */
132 	result = usb_submit_urb(urb, GFP_ATOMIC);
133 	if (result)
134 		dev_dbg(&port->dev,
135 			"%s - failed submitting interrupt in urb, error code=%d\n",
136 			__func__, result);
137 }
138 
139 static void metrousb_cleanup(struct usb_serial_port *port)
140 {
141 	dev_dbg(&port->dev, "%s\n", __func__);
142 
143 	if (port->serial->dev) {
144 		/* Shutdown any interrupt in urbs. */
145 		if (port->interrupt_in_urb) {
146 			usb_unlink_urb(port->interrupt_in_urb);
147 			usb_kill_urb(port->interrupt_in_urb);
148 		}
149 	}
150 }
151 
152 static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)
153 {
154 	struct usb_serial *serial = port->serial;
155 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
156 	unsigned long flags = 0;
157 	int result = 0;
158 
159 	dev_dbg(&port->dev, "%s\n", __func__);
160 
161 	/* Make sure the urb is initialized. */
162 	if (!port->interrupt_in_urb) {
163 		dev_dbg(&port->dev, "%s - interrupt urb not initialized\n",
164 			__func__);
165 		return -ENODEV;
166 	}
167 
168 	/* Set the private data information for the port. */
169 	spin_lock_irqsave(&metro_priv->lock, flags);
170 	metro_priv->control_state = 0;
171 	metro_priv->throttled = 0;
172 	spin_unlock_irqrestore(&metro_priv->lock, flags);
173 
174 	/*
175 	 * Force low_latency on so that our tty_push actually forces the data
176 	 * through, otherwise it is scheduled, and with high data rates (like
177 	 * with OHCI) data can get lost.
178 	 */
179 	if (tty)
180 		tty->low_latency = 1;
181 
182 	/* Clear the urb pipe. */
183 	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);
184 
185 	/* Start reading from the device */
186 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
187 			  usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
188 			   port->interrupt_in_urb->transfer_buffer,
189 			   port->interrupt_in_urb->transfer_buffer_length,
190 			   metrousb_read_int_callback, port, 1);
191 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
192 
193 	if (result) {
194 		dev_dbg(&port->dev,
195 			"%s - failed submitting interrupt in urb, error code=%d\n",
196 			__func__, result);
197 		goto exit;
198 	}
199 
200 	dev_dbg(&port->dev, "%s - port open\n", __func__);
201 exit:
202 	return result;
203 }
204 
205 static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
206 {
207 	int retval = 0;
208 	unsigned char mcr = METROUSB_MCR_NONE;
209 
210 	dev_dbg(&serial->dev->dev, "%s - control state = %d\n",
211 		__func__, control_state);
212 
213 	/* Set the modem control value. */
214 	if (control_state & TIOCM_DTR)
215 		mcr |= METROUSB_MCR_DTR;
216 	if (control_state & TIOCM_RTS)
217 		mcr |= METROUSB_MCR_RTS;
218 
219 	/* Send the command to the usb port. */
220 	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
221 				METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
222 				control_state, 0, NULL, 0, WDR_TIMEOUT);
223 	if (retval < 0)
224 		dev_dbg(&serial->dev->dev,
225 			"%s - set modem ctrl=0x%x failed, error code=%d\n",
226 			__func__, mcr, retval);
227 
228 	return retval;
229 }
230 
231 static void metrousb_shutdown(struct usb_serial *serial)
232 {
233 	int i = 0;
234 
235 	dev_dbg(&serial->dev->dev, "%s\n", __func__);
236 
237 	/* Stop reading and writing on all ports. */
238 	for (i = 0; i < serial->num_ports; ++i) {
239 		/* Close any open urbs. */
240 		metrousb_cleanup(serial->port[i]);
241 
242 		/* Free memory. */
243 		kfree(usb_get_serial_port_data(serial->port[i]));
244 		usb_set_serial_port_data(serial->port[i], NULL);
245 
246 		dev_dbg(&serial->dev->dev, "%s - freed port number=%d\n",
247 			__func__, serial->port[i]->number);
248 	}
249 }
250 
251 static int metrousb_startup(struct usb_serial *serial)
252 {
253 	struct metrousb_private *metro_priv;
254 	struct usb_serial_port *port;
255 	int i = 0;
256 
257 	dev_dbg(&serial->dev->dev, "%s\n", __func__);
258 
259 	/* Loop through the serial ports setting up the private structures.
260 	 * Currently we only use one port. */
261 	for (i = 0; i < serial->num_ports; ++i) {
262 		port = serial->port[i];
263 
264 		/* Declare memory. */
265 		metro_priv = kzalloc(sizeof(struct metrousb_private), GFP_KERNEL);
266 		if (!metro_priv)
267 			return -ENOMEM;
268 
269 		/* Initialize memory. */
270 		spin_lock_init(&metro_priv->lock);
271 		usb_set_serial_port_data(port, metro_priv);
272 
273 		dev_dbg(&serial->dev->dev, "%s - port number=%d\n ",
274 			__func__, port->number);
275 	}
276 
277 	return 0;
278 }
279 
280 static void metrousb_throttle(struct tty_struct *tty)
281 {
282 	struct usb_serial_port *port = tty->driver_data;
283 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
284 	unsigned long flags = 0;
285 
286 	dev_dbg(tty->dev, "%s\n", __func__);
287 
288 	/* Set the private information for the port to stop reading data. */
289 	spin_lock_irqsave(&metro_priv->lock, flags);
290 	metro_priv->throttled = 1;
291 	spin_unlock_irqrestore(&metro_priv->lock, flags);
292 }
293 
294 static int metrousb_tiocmget(struct tty_struct *tty)
295 {
296 	unsigned long control_state = 0;
297 	struct usb_serial_port *port = tty->driver_data;
298 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
299 	unsigned long flags = 0;
300 
301 	dev_dbg(tty->dev, "%s\n", __func__);
302 
303 	spin_lock_irqsave(&metro_priv->lock, flags);
304 	control_state = metro_priv->control_state;
305 	spin_unlock_irqrestore(&metro_priv->lock, flags);
306 
307 	return control_state;
308 }
309 
310 static int metrousb_tiocmset(struct tty_struct *tty,
311 			     unsigned int set, unsigned int clear)
312 {
313 	struct usb_serial_port *port = tty->driver_data;
314 	struct usb_serial *serial = port->serial;
315 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
316 	unsigned long flags = 0;
317 	unsigned long control_state = 0;
318 
319 	dev_dbg(tty->dev, "%s - set=%d, clear=%d\n", __func__, set, clear);
320 
321 	spin_lock_irqsave(&metro_priv->lock, flags);
322 	control_state = metro_priv->control_state;
323 
324 	/* Set the RTS and DTR values. */
325 	if (set & TIOCM_RTS)
326 		control_state |= TIOCM_RTS;
327 	if (set & TIOCM_DTR)
328 		control_state |= TIOCM_DTR;
329 	if (clear & TIOCM_RTS)
330 		control_state &= ~TIOCM_RTS;
331 	if (clear & TIOCM_DTR)
332 		control_state &= ~TIOCM_DTR;
333 
334 	metro_priv->control_state = control_state;
335 	spin_unlock_irqrestore(&metro_priv->lock, flags);
336 	return metrousb_set_modem_ctrl(serial, control_state);
337 }
338 
339 static void metrousb_unthrottle(struct tty_struct *tty)
340 {
341 	struct usb_serial_port *port = tty->driver_data;
342 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
343 	unsigned long flags = 0;
344 	int result = 0;
345 
346 	dev_dbg(tty->dev, "%s\n", __func__);
347 
348 	/* Set the private information for the port to resume reading data. */
349 	spin_lock_irqsave(&metro_priv->lock, flags);
350 	metro_priv->throttled = 0;
351 	spin_unlock_irqrestore(&metro_priv->lock, flags);
352 
353 	/* Submit the urb to read from the port. */
354 	port->interrupt_in_urb->dev = port->serial->dev;
355 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
356 	if (result)
357 		dev_dbg(tty->dev,
358 			"failed submitting interrupt in urb error code=%d\n",
359 			result);
360 }
361 
362 static struct usb_driver metrousb_driver = {
363 	.name =		"metro-usb",
364 	.probe =	usb_serial_probe,
365 	.disconnect =	usb_serial_disconnect,
366 	.id_table =	id_table
367 };
368 
369 static struct usb_serial_driver metrousb_device = {
370 	.driver = {
371 		.owner =	THIS_MODULE,
372 		.name =		"metro-usb",
373 	},
374 	.description		= "Metrologic USB to serial converter.",
375 	.id_table		= id_table,
376 	.num_ports		= 1,
377 	.open			= metrousb_open,
378 	.close			= metrousb_cleanup,
379 	.read_int_callback	= metrousb_read_int_callback,
380 	.attach			= metrousb_startup,
381 	.release		= metrousb_shutdown,
382 	.throttle		= metrousb_throttle,
383 	.unthrottle		= metrousb_unthrottle,
384 	.tiocmget		= metrousb_tiocmget,
385 	.tiocmset		= metrousb_tiocmset,
386 };
387 
388 static struct usb_serial_driver * const serial_drivers[] = {
389 	&metrousb_device,
390 	NULL,
391 };
392 
393 module_usb_serial_driver(metrousb_driver, serial_drivers);
394 
395 MODULE_LICENSE("GPL");
396 MODULE_AUTHOR("Philip Nicastro");
397 MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
398 MODULE_DESCRIPTION(DRIVER_DESC);
399 
400 /* Module input parameters */
401 module_param(debug, bool, S_IRUGO | S_IWUSR);
402 MODULE_PARM_DESC(debug, "Print debug info (bool 1=on, 0=off)");
403