xref: /openbmc/linux/drivers/usb/serial/metro-usb.c (revision b6bec26c)
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/uaccess.h>
21 #include <linux/usb/serial.h>
22 
23 #define DRIVER_DESC "Metrologic Instruments Inc. - USB-POS driver"
24 
25 /* Product information. */
26 #define FOCUS_VENDOR_ID			0x0C2E
27 #define FOCUS_PRODUCT_ID_BI		0x0720
28 #define FOCUS_PRODUCT_ID_UNI		0x0700
29 
30 #define METROUSB_SET_REQUEST_TYPE	0x40
31 #define METROUSB_SET_MODEM_CTRL_REQUEST	10
32 #define METROUSB_SET_BREAK_REQUEST	0x40
33 #define METROUSB_MCR_NONE		0x08	/* Deactivate DTR and RTS. */
34 #define METROUSB_MCR_RTS		0x0a	/* Activate RTS. */
35 #define METROUSB_MCR_DTR		0x09	/* Activate DTR. */
36 #define WDR_TIMEOUT			5000	/* default urb timeout. */
37 
38 /* Private data structure. */
39 struct metrousb_private {
40 	spinlock_t lock;
41 	int throttled;
42 	unsigned long control_state;
43 };
44 
45 /* Device table list. */
46 static struct usb_device_id id_table[] = {
47 	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_BI) },
48 	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_UNI) },
49 	{ }, /* Terminating entry. */
50 };
51 MODULE_DEVICE_TABLE(usb, id_table);
52 
53 /* UNI-Directional mode commands for device configure */
54 #define UNI_CMD_OPEN	0x80
55 #define UNI_CMD_CLOSE	0xFF
56 
57 inline int metrousb_is_unidirectional_mode(struct usb_serial_port *port)
58 {
59 	__u16 product_id = le16_to_cpu(
60 		port->serial->dev->descriptor.idProduct);
61 
62 	return product_id == FOCUS_PRODUCT_ID_UNI;
63 }
64 
65 static int metrousb_send_unidirectional_cmd(u8 cmd, struct usb_serial_port *port)
66 {
67 	int ret;
68 	int actual_len;
69 	u8 *buffer_cmd = NULL;
70 
71 	if (!metrousb_is_unidirectional_mode(port))
72 		return 0;
73 
74 	buffer_cmd = kzalloc(sizeof(cmd), GFP_KERNEL);
75 	if (!buffer_cmd)
76 		return -ENOMEM;
77 
78 	*buffer_cmd = cmd;
79 
80 	ret = usb_interrupt_msg(port->serial->dev,
81 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
82 		buffer_cmd, sizeof(cmd),
83 		&actual_len, USB_CTRL_SET_TIMEOUT);
84 
85 	kfree(buffer_cmd);
86 
87 	if (ret < 0)
88 		return ret;
89 	else if (actual_len != sizeof(cmd))
90 		return -EIO;
91 	return 0;
92 }
93 
94 static void metrousb_read_int_callback(struct urb *urb)
95 {
96 	struct usb_serial_port *port = urb->context;
97 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
98 	struct tty_struct *tty;
99 	unsigned char *data = urb->transfer_buffer;
100 	int throttled = 0;
101 	int result = 0;
102 	unsigned long flags = 0;
103 
104 	dev_dbg(&port->dev, "%s\n", __func__);
105 
106 	switch (urb->status) {
107 	case 0:
108 		/* Success status, read from the port. */
109 		break;
110 	case -ECONNRESET:
111 	case -ENOENT:
112 	case -ESHUTDOWN:
113 		/* urb has been terminated. */
114 		dev_dbg(&port->dev,
115 			"%s - urb shutting down, error code=%d\n",
116 			__func__, urb->status);
117 		return;
118 	default:
119 		dev_dbg(&port->dev,
120 			"%s - non-zero urb received, error code=%d\n",
121 			__func__, urb->status);
122 		goto exit;
123 	}
124 
125 
126 	/* Set the data read from the usb port into the serial port buffer. */
127 	tty = tty_port_tty_get(&port->port);
128 	if (tty && urb->actual_length) {
129 		/* Loop through the data copying each byte to the tty layer. */
130 		tty_insert_flip_string(tty, data, urb->actual_length);
131 
132 		/* Force the data to the tty layer. */
133 		tty_flip_buffer_push(tty);
134 	}
135 	tty_kref_put(tty);
136 
137 	/* Set any port variables. */
138 	spin_lock_irqsave(&metro_priv->lock, flags);
139 	throttled = metro_priv->throttled;
140 	spin_unlock_irqrestore(&metro_priv->lock, flags);
141 
142 	/* Continue trying to read if set. */
143 	if (!throttled) {
144 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
145 				 usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
146 				 port->interrupt_in_urb->transfer_buffer,
147 				 port->interrupt_in_urb->transfer_buffer_length,
148 				 metrousb_read_int_callback, port, 1);
149 
150 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
151 
152 		if (result)
153 			dev_err(&port->dev,
154 				"%s - failed submitting interrupt in urb, error code=%d\n",
155 				__func__, result);
156 	}
157 	return;
158 
159 exit:
160 	/* Try to resubmit the urb. */
161 	result = usb_submit_urb(urb, GFP_ATOMIC);
162 	if (result)
163 		dev_err(&port->dev,
164 			"%s - failed submitting interrupt in urb, error code=%d\n",
165 			__func__, result);
166 }
167 
168 static void metrousb_write_int_callback(struct urb *urb)
169 {
170 	struct usb_serial_port *port = urb->context;
171 
172 	dev_warn(&port->dev, "%s not implemented yet.\n",
173 		__func__);
174 }
175 
176 static void metrousb_cleanup(struct usb_serial_port *port)
177 {
178 	dev_dbg(&port->dev, "%s\n", __func__);
179 
180 	usb_unlink_urb(port->interrupt_in_urb);
181 	usb_kill_urb(port->interrupt_in_urb);
182 
183 	mutex_lock(&port->serial->disc_mutex);
184 	if (!port->serial->disconnected)
185 		metrousb_send_unidirectional_cmd(UNI_CMD_CLOSE, port);
186 	mutex_unlock(&port->serial->disc_mutex);
187 }
188 
189 static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)
190 {
191 	struct usb_serial *serial = port->serial;
192 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
193 	unsigned long flags = 0;
194 	int result = 0;
195 
196 	dev_dbg(&port->dev, "%s\n", __func__);
197 
198 	/* Make sure the urb is initialized. */
199 	if (!port->interrupt_in_urb) {
200 		dev_err(&port->dev, "%s - interrupt urb not initialized\n",
201 			__func__);
202 		return -ENODEV;
203 	}
204 
205 	/* Set the private data information for the port. */
206 	spin_lock_irqsave(&metro_priv->lock, flags);
207 	metro_priv->control_state = 0;
208 	metro_priv->throttled = 0;
209 	spin_unlock_irqrestore(&metro_priv->lock, flags);
210 
211 	/* Clear the urb pipe. */
212 	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);
213 
214 	/* Start reading from the device */
215 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
216 			  usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
217 			   port->interrupt_in_urb->transfer_buffer,
218 			   port->interrupt_in_urb->transfer_buffer_length,
219 			   metrousb_read_int_callback, port, 1);
220 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
221 
222 	if (result) {
223 		dev_err(&port->dev,
224 			"%s - failed submitting interrupt in urb, error code=%d\n",
225 			__func__, result);
226 		goto exit;
227 	}
228 
229 	/* Send activate cmd to device */
230 	result = metrousb_send_unidirectional_cmd(UNI_CMD_OPEN, port);
231 	if (result) {
232 		dev_err(&port->dev,
233 			"%s - failed to configure device for port number=%d, error code=%d\n",
234 			__func__, port->number, result);
235 		goto exit;
236 	}
237 
238 	dev_dbg(&port->dev, "%s - port open\n", __func__);
239 exit:
240 	return result;
241 }
242 
243 static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
244 {
245 	int retval = 0;
246 	unsigned char mcr = METROUSB_MCR_NONE;
247 
248 	dev_dbg(&serial->dev->dev, "%s - control state = %d\n",
249 		__func__, control_state);
250 
251 	/* Set the modem control value. */
252 	if (control_state & TIOCM_DTR)
253 		mcr |= METROUSB_MCR_DTR;
254 	if (control_state & TIOCM_RTS)
255 		mcr |= METROUSB_MCR_RTS;
256 
257 	/* Send the command to the usb port. */
258 	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
259 				METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
260 				control_state, 0, NULL, 0, WDR_TIMEOUT);
261 	if (retval < 0)
262 		dev_err(&serial->dev->dev,
263 			"%s - set modem ctrl=0x%x failed, error code=%d\n",
264 			__func__, mcr, retval);
265 
266 	return retval;
267 }
268 
269 static int metrousb_port_probe(struct usb_serial_port *port)
270 {
271 	struct metrousb_private *metro_priv;
272 
273 	metro_priv = kzalloc(sizeof(*metro_priv), GFP_KERNEL);
274 	if (!metro_priv)
275 		return -ENOMEM;
276 
277 	spin_lock_init(&metro_priv->lock);
278 
279 	usb_set_serial_port_data(port, metro_priv);
280 
281 	return 0;
282 }
283 
284 static int metrousb_port_remove(struct usb_serial_port *port)
285 {
286 	struct metrousb_private *metro_priv;
287 
288 	metro_priv = usb_get_serial_port_data(port);
289 	kfree(metro_priv);
290 
291 	return 0;
292 }
293 
294 static void metrousb_throttle(struct tty_struct *tty)
295 {
296 	struct usb_serial_port *port = tty->driver_data;
297 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
298 	unsigned long flags = 0;
299 
300 	dev_dbg(tty->dev, "%s\n", __func__);
301 
302 	/* Set the private information for the port to stop reading data. */
303 	spin_lock_irqsave(&metro_priv->lock, flags);
304 	metro_priv->throttled = 1;
305 	spin_unlock_irqrestore(&metro_priv->lock, flags);
306 }
307 
308 static int metrousb_tiocmget(struct tty_struct *tty)
309 {
310 	unsigned long control_state = 0;
311 	struct usb_serial_port *port = tty->driver_data;
312 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
313 	unsigned long flags = 0;
314 
315 	dev_dbg(tty->dev, "%s\n", __func__);
316 
317 	spin_lock_irqsave(&metro_priv->lock, flags);
318 	control_state = metro_priv->control_state;
319 	spin_unlock_irqrestore(&metro_priv->lock, flags);
320 
321 	return control_state;
322 }
323 
324 static int metrousb_tiocmset(struct tty_struct *tty,
325 			     unsigned int set, unsigned int clear)
326 {
327 	struct usb_serial_port *port = tty->driver_data;
328 	struct usb_serial *serial = port->serial;
329 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
330 	unsigned long flags = 0;
331 	unsigned long control_state = 0;
332 
333 	dev_dbg(tty->dev, "%s - set=%d, clear=%d\n", __func__, set, clear);
334 
335 	spin_lock_irqsave(&metro_priv->lock, flags);
336 	control_state = metro_priv->control_state;
337 
338 	/* Set the RTS and DTR values. */
339 	if (set & TIOCM_RTS)
340 		control_state |= TIOCM_RTS;
341 	if (set & TIOCM_DTR)
342 		control_state |= TIOCM_DTR;
343 	if (clear & TIOCM_RTS)
344 		control_state &= ~TIOCM_RTS;
345 	if (clear & TIOCM_DTR)
346 		control_state &= ~TIOCM_DTR;
347 
348 	metro_priv->control_state = control_state;
349 	spin_unlock_irqrestore(&metro_priv->lock, flags);
350 	return metrousb_set_modem_ctrl(serial, control_state);
351 }
352 
353 static void metrousb_unthrottle(struct tty_struct *tty)
354 {
355 	struct usb_serial_port *port = tty->driver_data;
356 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
357 	unsigned long flags = 0;
358 	int result = 0;
359 
360 	dev_dbg(tty->dev, "%s\n", __func__);
361 
362 	/* Set the private information for the port to resume reading data. */
363 	spin_lock_irqsave(&metro_priv->lock, flags);
364 	metro_priv->throttled = 0;
365 	spin_unlock_irqrestore(&metro_priv->lock, flags);
366 
367 	/* Submit the urb to read from the port. */
368 	port->interrupt_in_urb->dev = port->serial->dev;
369 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
370 	if (result)
371 		dev_err(tty->dev,
372 			"failed submitting interrupt in urb error code=%d\n",
373 			result);
374 }
375 
376 static struct usb_serial_driver metrousb_device = {
377 	.driver = {
378 		.owner =	THIS_MODULE,
379 		.name =		"metro-usb",
380 	},
381 	.description		= "Metrologic USB to Serial",
382 	.id_table		= id_table,
383 	.num_ports		= 1,
384 	.open			= metrousb_open,
385 	.close			= metrousb_cleanup,
386 	.read_int_callback	= metrousb_read_int_callback,
387 	.write_int_callback	= metrousb_write_int_callback,
388 	.port_probe		= metrousb_port_probe,
389 	.port_remove		= metrousb_port_remove,
390 	.throttle		= metrousb_throttle,
391 	.unthrottle		= metrousb_unthrottle,
392 	.tiocmget		= metrousb_tiocmget,
393 	.tiocmset		= metrousb_tiocmset,
394 };
395 
396 static struct usb_serial_driver * const serial_drivers[] = {
397 	&metrousb_device,
398 	NULL,
399 };
400 
401 module_usb_serial_driver(serial_drivers, id_table);
402 
403 MODULE_LICENSE("GPL");
404 MODULE_AUTHOR("Philip Nicastro");
405 MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
406 MODULE_DESCRIPTION(DRIVER_DESC);
407