xref: /openbmc/linux/drivers/usb/serial/metro-usb.c (revision 4f6cce39)
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/tty.h>
11 #include <linux/module.h>
12 #include <linux/usb.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/tty_driver.h>
16 #include <linux/tty_flip.h>
17 #include <linux/moduleparam.h>
18 #include <linux/spinlock.h>
19 #include <linux/uaccess.h>
20 #include <linux/usb/serial.h>
21 
22 #define DRIVER_DESC "Metrologic Instruments Inc. - USB-POS driver"
23 
24 /* Product information. */
25 #define FOCUS_VENDOR_ID			0x0C2E
26 #define FOCUS_PRODUCT_ID_BI		0x0720
27 #define FOCUS_PRODUCT_ID_UNI		0x0700
28 
29 #define METROUSB_SET_REQUEST_TYPE	0x40
30 #define METROUSB_SET_MODEM_CTRL_REQUEST	10
31 #define METROUSB_SET_BREAK_REQUEST	0x40
32 #define METROUSB_MCR_NONE		0x08	/* Deactivate DTR and RTS. */
33 #define METROUSB_MCR_RTS		0x0a	/* Activate RTS. */
34 #define METROUSB_MCR_DTR		0x09	/* Activate DTR. */
35 #define WDR_TIMEOUT			5000	/* default urb timeout. */
36 
37 /* Private data structure. */
38 struct metrousb_private {
39 	spinlock_t lock;
40 	int throttled;
41 	unsigned long control_state;
42 };
43 
44 /* Device table list. */
45 static const struct usb_device_id id_table[] = {
46 	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_BI) },
47 	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_UNI) },
48 	{ }, /* Terminating entry. */
49 };
50 MODULE_DEVICE_TABLE(usb, id_table);
51 
52 /* UNI-Directional mode commands for device configure */
53 #define UNI_CMD_OPEN	0x80
54 #define UNI_CMD_CLOSE	0xFF
55 
56 static inline int metrousb_is_unidirectional_mode(struct usb_serial_port *port)
57 {
58 	__u16 product_id = le16_to_cpu(
59 		port->serial->dev->descriptor.idProduct);
60 
61 	return product_id == FOCUS_PRODUCT_ID_UNI;
62 }
63 
64 static int metrousb_send_unidirectional_cmd(u8 cmd, struct usb_serial_port *port)
65 {
66 	int ret;
67 	int actual_len;
68 	u8 *buffer_cmd = NULL;
69 
70 	if (!metrousb_is_unidirectional_mode(port))
71 		return 0;
72 
73 	buffer_cmd = kzalloc(sizeof(cmd), GFP_KERNEL);
74 	if (!buffer_cmd)
75 		return -ENOMEM;
76 
77 	*buffer_cmd = cmd;
78 
79 	ret = usb_interrupt_msg(port->serial->dev,
80 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
81 		buffer_cmd, sizeof(cmd),
82 		&actual_len, USB_CTRL_SET_TIMEOUT);
83 
84 	kfree(buffer_cmd);
85 
86 	if (ret < 0)
87 		return ret;
88 	else if (actual_len != sizeof(cmd))
89 		return -EIO;
90 	return 0;
91 }
92 
93 static void metrousb_read_int_callback(struct urb *urb)
94 {
95 	struct usb_serial_port *port = urb->context;
96 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
97 	unsigned char *data = urb->transfer_buffer;
98 	int throttled = 0;
99 	int result = 0;
100 	unsigned long flags = 0;
101 
102 	dev_dbg(&port->dev, "%s\n", __func__);
103 
104 	switch (urb->status) {
105 	case 0:
106 		/* Success status, read from the port. */
107 		break;
108 	case -ECONNRESET:
109 	case -ENOENT:
110 	case -ESHUTDOWN:
111 		/* urb has been terminated. */
112 		dev_dbg(&port->dev,
113 			"%s - urb shutting down, error code=%d\n",
114 			__func__, urb->status);
115 		return;
116 	default:
117 		dev_dbg(&port->dev,
118 			"%s - non-zero urb received, error code=%d\n",
119 			__func__, urb->status);
120 		goto exit;
121 	}
122 
123 
124 	/* Set the data read from the usb port into the serial port buffer. */
125 	if (urb->actual_length) {
126 		/* Loop through the data copying each byte to the tty layer. */
127 		tty_insert_flip_string(&port->port, data, urb->actual_length);
128 
129 		/* Force the data to the tty layer. */
130 		tty_flip_buffer_push(&port->port);
131 	}
132 
133 	/* Set any port variables. */
134 	spin_lock_irqsave(&metro_priv->lock, flags);
135 	throttled = metro_priv->throttled;
136 	spin_unlock_irqrestore(&metro_priv->lock, flags);
137 
138 	if (throttled)
139 		return;
140 exit:
141 	/* Try to resubmit the urb. */
142 	result = usb_submit_urb(urb, GFP_ATOMIC);
143 	if (result)
144 		dev_err(&port->dev,
145 			"%s - failed submitting interrupt in urb, error code=%d\n",
146 			__func__, result);
147 }
148 
149 static void metrousb_cleanup(struct usb_serial_port *port)
150 {
151 	usb_kill_urb(port->interrupt_in_urb);
152 
153 	metrousb_send_unidirectional_cmd(UNI_CMD_CLOSE, port);
154 }
155 
156 static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)
157 {
158 	struct usb_serial *serial = port->serial;
159 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
160 	unsigned long flags = 0;
161 	int result = 0;
162 
163 	/* Make sure the urb is initialized. */
164 	if (!port->interrupt_in_urb) {
165 		dev_err(&port->dev, "%s - interrupt urb not initialized\n",
166 			__func__);
167 		return -ENODEV;
168 	}
169 
170 	/* Set the private data information for the port. */
171 	spin_lock_irqsave(&metro_priv->lock, flags);
172 	metro_priv->control_state = 0;
173 	metro_priv->throttled = 0;
174 	spin_unlock_irqrestore(&metro_priv->lock, flags);
175 
176 	/* Clear the urb pipe. */
177 	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);
178 
179 	/* Start reading from the device */
180 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
181 			  usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
182 			   port->interrupt_in_urb->transfer_buffer,
183 			   port->interrupt_in_urb->transfer_buffer_length,
184 			   metrousb_read_int_callback, port, 1);
185 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
186 
187 	if (result) {
188 		dev_err(&port->dev,
189 			"%s - failed submitting interrupt in urb, error code=%d\n",
190 			__func__, result);
191 		goto exit;
192 	}
193 
194 	/* Send activate cmd to device */
195 	result = metrousb_send_unidirectional_cmd(UNI_CMD_OPEN, port);
196 	if (result) {
197 		dev_err(&port->dev,
198 			"%s - failed to configure device, error code=%d\n",
199 			__func__, result);
200 		goto exit;
201 	}
202 exit:
203 	return result;
204 }
205 
206 static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
207 {
208 	int retval = 0;
209 	unsigned char mcr = METROUSB_MCR_NONE;
210 
211 	dev_dbg(&serial->dev->dev, "%s - control state = %d\n",
212 		__func__, control_state);
213 
214 	/* Set the modem control value. */
215 	if (control_state & TIOCM_DTR)
216 		mcr |= METROUSB_MCR_DTR;
217 	if (control_state & TIOCM_RTS)
218 		mcr |= METROUSB_MCR_RTS;
219 
220 	/* Send the command to the usb port. */
221 	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
222 				METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
223 				control_state, 0, NULL, 0, WDR_TIMEOUT);
224 	if (retval < 0)
225 		dev_err(&serial->dev->dev,
226 			"%s - set modem ctrl=0x%x failed, error code=%d\n",
227 			__func__, mcr, retval);
228 
229 	return retval;
230 }
231 
232 static int metrousb_port_probe(struct usb_serial_port *port)
233 {
234 	struct metrousb_private *metro_priv;
235 
236 	metro_priv = kzalloc(sizeof(*metro_priv), GFP_KERNEL);
237 	if (!metro_priv)
238 		return -ENOMEM;
239 
240 	spin_lock_init(&metro_priv->lock);
241 
242 	usb_set_serial_port_data(port, metro_priv);
243 
244 	return 0;
245 }
246 
247 static int metrousb_port_remove(struct usb_serial_port *port)
248 {
249 	struct metrousb_private *metro_priv;
250 
251 	metro_priv = usb_get_serial_port_data(port);
252 	kfree(metro_priv);
253 
254 	return 0;
255 }
256 
257 static void metrousb_throttle(struct tty_struct *tty)
258 {
259 	struct usb_serial_port *port = tty->driver_data;
260 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
261 	unsigned long flags = 0;
262 
263 	/* Set the private information for the port to stop reading data. */
264 	spin_lock_irqsave(&metro_priv->lock, flags);
265 	metro_priv->throttled = 1;
266 	spin_unlock_irqrestore(&metro_priv->lock, flags);
267 }
268 
269 static int metrousb_tiocmget(struct tty_struct *tty)
270 {
271 	unsigned long control_state = 0;
272 	struct usb_serial_port *port = tty->driver_data;
273 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
274 	unsigned long flags = 0;
275 
276 	spin_lock_irqsave(&metro_priv->lock, flags);
277 	control_state = metro_priv->control_state;
278 	spin_unlock_irqrestore(&metro_priv->lock, flags);
279 
280 	return control_state;
281 }
282 
283 static int metrousb_tiocmset(struct tty_struct *tty,
284 			     unsigned int set, unsigned int clear)
285 {
286 	struct usb_serial_port *port = tty->driver_data;
287 	struct usb_serial *serial = port->serial;
288 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
289 	unsigned long flags = 0;
290 	unsigned long control_state = 0;
291 
292 	dev_dbg(tty->dev, "%s - set=%d, clear=%d\n", __func__, set, clear);
293 
294 	spin_lock_irqsave(&metro_priv->lock, flags);
295 	control_state = metro_priv->control_state;
296 
297 	/* Set the RTS and DTR values. */
298 	if (set & TIOCM_RTS)
299 		control_state |= TIOCM_RTS;
300 	if (set & TIOCM_DTR)
301 		control_state |= TIOCM_DTR;
302 	if (clear & TIOCM_RTS)
303 		control_state &= ~TIOCM_RTS;
304 	if (clear & TIOCM_DTR)
305 		control_state &= ~TIOCM_DTR;
306 
307 	metro_priv->control_state = control_state;
308 	spin_unlock_irqrestore(&metro_priv->lock, flags);
309 	return metrousb_set_modem_ctrl(serial, control_state);
310 }
311 
312 static void metrousb_unthrottle(struct tty_struct *tty)
313 {
314 	struct usb_serial_port *port = tty->driver_data;
315 	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
316 	unsigned long flags = 0;
317 	int result = 0;
318 
319 	/* Set the private information for the port to resume reading data. */
320 	spin_lock_irqsave(&metro_priv->lock, flags);
321 	metro_priv->throttled = 0;
322 	spin_unlock_irqrestore(&metro_priv->lock, flags);
323 
324 	/* Submit the urb to read from the port. */
325 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
326 	if (result)
327 		dev_err(tty->dev,
328 			"failed submitting interrupt in urb error code=%d\n",
329 			result);
330 }
331 
332 static struct usb_serial_driver metrousb_device = {
333 	.driver = {
334 		.owner =	THIS_MODULE,
335 		.name =		"metro-usb",
336 	},
337 	.description		= "Metrologic USB to Serial",
338 	.id_table		= id_table,
339 	.num_ports		= 1,
340 	.open			= metrousb_open,
341 	.close			= metrousb_cleanup,
342 	.read_int_callback	= metrousb_read_int_callback,
343 	.port_probe		= metrousb_port_probe,
344 	.port_remove		= metrousb_port_remove,
345 	.throttle		= metrousb_throttle,
346 	.unthrottle		= metrousb_unthrottle,
347 	.tiocmget		= metrousb_tiocmget,
348 	.tiocmset		= metrousb_tiocmset,
349 };
350 
351 static struct usb_serial_driver * const serial_drivers[] = {
352 	&metrousb_device,
353 	NULL,
354 };
355 
356 module_usb_serial_driver(serial_drivers, id_table);
357 
358 MODULE_LICENSE("GPL");
359 MODULE_AUTHOR("Philip Nicastro");
360 MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
361 MODULE_DESCRIPTION(DRIVER_DESC);
362