1// SPDX-License-Identifier: GPL-2.0
2/*
3  Some of this code is credited to Linux USB open source files that are
4  distributed with Linux.
5
6  Copyright:	2007 Metrologic Instruments. All rights reserved.
7  Copyright:	2011 Azimut Ltd. <http://azimutrzn.ru/>
8*/
9
10#include <linux/kernel.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. */
39struct metrousb_private {
40	spinlock_t lock;
41	int throttled;
42	unsigned long control_state;
43};
44
45/* Device table list. */
46static const 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	{ USB_DEVICE_INTERFACE_CLASS(0x0c2e, 0x0730, 0xff) },	/* MS7820 */
50	{ }, /* Terminating entry. */
51};
52MODULE_DEVICE_TABLE(usb, id_table);
53
54/* UNI-Directional mode commands for device configure */
55#define UNI_CMD_OPEN	0x80
56#define UNI_CMD_CLOSE	0xFF
57
58static int metrousb_is_unidirectional_mode(struct usb_serial *serial)
59{
60	u16 product_id = le16_to_cpu(serial->dev->descriptor.idProduct);
61
62	return product_id == FOCUS_PRODUCT_ID_UNI;
63}
64
65static int metrousb_calc_num_ports(struct usb_serial *serial,
66				   struct usb_serial_endpoints *epds)
67{
68	if (metrousb_is_unidirectional_mode(serial)) {
69		if (epds->num_interrupt_out == 0) {
70			dev_err(&serial->interface->dev, "interrupt-out endpoint missing\n");
71			return -ENODEV;
72		}
73	}
74
75	return 1;
76}
77
78static int metrousb_send_unidirectional_cmd(u8 cmd, struct usb_serial_port *port)
79{
80	int ret;
81	int actual_len;
82	u8 *buffer_cmd = NULL;
83
84	if (!metrousb_is_unidirectional_mode(port->serial))
85		return 0;
86
87	buffer_cmd = kzalloc(sizeof(cmd), GFP_KERNEL);
88	if (!buffer_cmd)
89		return -ENOMEM;
90
91	*buffer_cmd = cmd;
92
93	ret = usb_interrupt_msg(port->serial->dev,
94		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
95		buffer_cmd, sizeof(cmd),
96		&actual_len, USB_CTRL_SET_TIMEOUT);
97
98	kfree(buffer_cmd);
99
100	if (ret < 0)
101		return ret;
102	else if (actual_len != sizeof(cmd))
103		return -EIO;
104	return 0;
105}
106
107static void metrousb_read_int_callback(struct urb *urb)
108{
109	struct usb_serial_port *port = urb->context;
110	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
111	unsigned char *data = urb->transfer_buffer;
112	unsigned long flags;
113	int throttled = 0;
114	int result = 0;
115
116	dev_dbg(&port->dev, "%s\n", __func__);
117
118	switch (urb->status) {
119	case 0:
120		/* Success status, read from the port. */
121		break;
122	case -ECONNRESET:
123	case -ENOENT:
124	case -ESHUTDOWN:
125		/* urb has been terminated. */
126		dev_dbg(&port->dev,
127			"%s - urb shutting down, error code=%d\n",
128			__func__, urb->status);
129		return;
130	default:
131		dev_dbg(&port->dev,
132			"%s - non-zero urb received, error code=%d\n",
133			__func__, urb->status);
134		goto exit;
135	}
136
137
138	/* Set the data read from the usb port into the serial port buffer. */
139	if (urb->actual_length) {
140		/* Loop through the data copying each byte to the tty layer. */
141		tty_insert_flip_string(&port->port, data, urb->actual_length);
142
143		/* Force the data to the tty layer. */
144		tty_flip_buffer_push(&port->port);
145	}
146
147	/* Set any port variables. */
148	spin_lock_irqsave(&metro_priv->lock, flags);
149	throttled = metro_priv->throttled;
150	spin_unlock_irqrestore(&metro_priv->lock, flags);
151
152	if (throttled)
153		return;
154exit:
155	/* Try to resubmit the urb. */
156	result = usb_submit_urb(urb, GFP_ATOMIC);
157	if (result)
158		dev_err(&port->dev,
159			"%s - failed submitting interrupt in urb, error code=%d\n",
160			__func__, result);
161}
162
163static void metrousb_cleanup(struct usb_serial_port *port)
164{
165	usb_kill_urb(port->interrupt_in_urb);
166
167	metrousb_send_unidirectional_cmd(UNI_CMD_CLOSE, port);
168}
169
170static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)
171{
172	struct usb_serial *serial = port->serial;
173	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
174	unsigned long flags;
175	int result = 0;
176
177	/* Set the private data information for the port. */
178	spin_lock_irqsave(&metro_priv->lock, flags);
179	metro_priv->control_state = 0;
180	metro_priv->throttled = 0;
181	spin_unlock_irqrestore(&metro_priv->lock, flags);
182
183	/* Clear the urb pipe. */
184	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);
185
186	/* Start reading from the device */
187	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
188			  usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
189			   port->interrupt_in_urb->transfer_buffer,
190			   port->interrupt_in_urb->transfer_buffer_length,
191			   metrousb_read_int_callback, port, 1);
192	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
193
194	if (result) {
195		dev_err(&port->dev,
196			"%s - failed submitting interrupt in urb, error code=%d\n",
197			__func__, result);
198		return result;
199	}
200
201	/* Send activate cmd to device */
202	result = metrousb_send_unidirectional_cmd(UNI_CMD_OPEN, port);
203	if (result) {
204		dev_err(&port->dev,
205			"%s - failed to configure device, error code=%d\n",
206			__func__, result);
207		goto err_kill_urb;
208	}
209
210	return 0;
211
212err_kill_urb:
213	usb_kill_urb(port->interrupt_in_urb);
214
215	return result;
216}
217
218static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
219{
220	int retval = 0;
221	unsigned char mcr = METROUSB_MCR_NONE;
222
223	dev_dbg(&serial->dev->dev, "%s - control state = %d\n",
224		__func__, control_state);
225
226	/* Set the modem control value. */
227	if (control_state & TIOCM_DTR)
228		mcr |= METROUSB_MCR_DTR;
229	if (control_state & TIOCM_RTS)
230		mcr |= METROUSB_MCR_RTS;
231
232	/* Send the command to the usb port. */
233	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
234				METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
235				control_state, 0, NULL, 0, WDR_TIMEOUT);
236	if (retval < 0)
237		dev_err(&serial->dev->dev,
238			"%s - set modem ctrl=0x%x failed, error code=%d\n",
239			__func__, mcr, retval);
240
241	return retval;
242}
243
244static int metrousb_port_probe(struct usb_serial_port *port)
245{
246	struct metrousb_private *metro_priv;
247
248	metro_priv = kzalloc(sizeof(*metro_priv), GFP_KERNEL);
249	if (!metro_priv)
250		return -ENOMEM;
251
252	spin_lock_init(&metro_priv->lock);
253
254	usb_set_serial_port_data(port, metro_priv);
255
256	return 0;
257}
258
259static void metrousb_port_remove(struct usb_serial_port *port)
260{
261	struct metrousb_private *metro_priv;
262
263	metro_priv = usb_get_serial_port_data(port);
264	kfree(metro_priv);
265}
266
267static void metrousb_throttle(struct tty_struct *tty)
268{
269	struct usb_serial_port *port = tty->driver_data;
270	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
271	unsigned long flags;
272
273	/* Set the private information for the port to stop reading data. */
274	spin_lock_irqsave(&metro_priv->lock, flags);
275	metro_priv->throttled = 1;
276	spin_unlock_irqrestore(&metro_priv->lock, flags);
277}
278
279static int metrousb_tiocmget(struct tty_struct *tty)
280{
281	unsigned long control_state = 0;
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;
285
286	spin_lock_irqsave(&metro_priv->lock, flags);
287	control_state = metro_priv->control_state;
288	spin_unlock_irqrestore(&metro_priv->lock, flags);
289
290	return control_state;
291}
292
293static int metrousb_tiocmset(struct tty_struct *tty,
294			     unsigned int set, unsigned int clear)
295{
296	struct usb_serial_port *port = tty->driver_data;
297	struct usb_serial *serial = port->serial;
298	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
299	unsigned long flags;
300	unsigned long control_state = 0;
301
302	dev_dbg(&port->dev, "%s - set=%d, clear=%d\n", __func__, set, clear);
303
304	spin_lock_irqsave(&metro_priv->lock, flags);
305	control_state = metro_priv->control_state;
306
307	/* Set the RTS and DTR values. */
308	if (set & TIOCM_RTS)
309		control_state |= TIOCM_RTS;
310	if (set & TIOCM_DTR)
311		control_state |= TIOCM_DTR;
312	if (clear & TIOCM_RTS)
313		control_state &= ~TIOCM_RTS;
314	if (clear & TIOCM_DTR)
315		control_state &= ~TIOCM_DTR;
316
317	metro_priv->control_state = control_state;
318	spin_unlock_irqrestore(&metro_priv->lock, flags);
319	return metrousb_set_modem_ctrl(serial, control_state);
320}
321
322static void metrousb_unthrottle(struct tty_struct *tty)
323{
324	struct usb_serial_port *port = tty->driver_data;
325	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
326	unsigned long flags;
327	int result = 0;
328
329	/* Set the private information for the port to resume reading data. */
330	spin_lock_irqsave(&metro_priv->lock, flags);
331	metro_priv->throttled = 0;
332	spin_unlock_irqrestore(&metro_priv->lock, flags);
333
334	/* Submit the urb to read from the port. */
335	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
336	if (result)
337		dev_err(&port->dev,
338			"failed submitting interrupt in urb error code=%d\n",
339			result);
340}
341
342static struct usb_serial_driver metrousb_device = {
343	.driver = {
344		.owner =	THIS_MODULE,
345		.name =		"metro-usb",
346	},
347	.description		= "Metrologic USB to Serial",
348	.id_table		= id_table,
349	.num_interrupt_in	= 1,
350	.calc_num_ports		= metrousb_calc_num_ports,
351	.open			= metrousb_open,
352	.close			= metrousb_cleanup,
353	.read_int_callback	= metrousb_read_int_callback,
354	.port_probe		= metrousb_port_probe,
355	.port_remove		= metrousb_port_remove,
356	.throttle		= metrousb_throttle,
357	.unthrottle		= metrousb_unthrottle,
358	.tiocmget		= metrousb_tiocmget,
359	.tiocmset		= metrousb_tiocmset,
360};
361
362static struct usb_serial_driver * const serial_drivers[] = {
363	&metrousb_device,
364	NULL,
365};
366
367module_usb_serial_driver(serial_drivers, id_table);
368
369MODULE_LICENSE("GPL v2");
370MODULE_AUTHOR("Philip Nicastro");
371MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
372MODULE_DESCRIPTION(DRIVER_DESC);
373