xref: /openbmc/linux/drivers/usb/serial/mos7840.c (revision c1d45424)
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * along with this program; if not, write to the Free Software
14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
15  *
16  * Clean ups from Moschip version and a few ioctl implementations by:
17  *	Paul B Schroeder <pschroeder "at" uplogix "dot" com>
18  *
19  * Originally based on drivers/usb/serial/io_edgeport.c which is:
20  *      Copyright (C) 2000 Inside Out Networks, All rights reserved.
21  *      Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
22  *
23  */
24 
25 #include <linux/kernel.h>
26 #include <linux/errno.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/tty.h>
30 #include <linux/tty_driver.h>
31 #include <linux/tty_flip.h>
32 #include <linux/module.h>
33 #include <linux/serial.h>
34 #include <linux/usb.h>
35 #include <linux/usb/serial.h>
36 #include <linux/uaccess.h>
37 
38 #define DRIVER_DESC "Moschip 7840/7820 USB Serial Driver"
39 
40 /*
41  * 16C50 UART register defines
42  */
43 
44 #define LCR_BITS_5             0x00	/* 5 bits/char */
45 #define LCR_BITS_6             0x01	/* 6 bits/char */
46 #define LCR_BITS_7             0x02	/* 7 bits/char */
47 #define LCR_BITS_8             0x03	/* 8 bits/char */
48 #define LCR_BITS_MASK          0x03	/* Mask for bits/char field */
49 
50 #define LCR_STOP_1             0x00	/* 1 stop bit */
51 #define LCR_STOP_1_5           0x04	/* 1.5 stop bits (if 5   bits/char) */
52 #define LCR_STOP_2             0x04	/* 2 stop bits   (if 6-8 bits/char) */
53 #define LCR_STOP_MASK          0x04	/* Mask for stop bits field */
54 
55 #define LCR_PAR_NONE           0x00	/* No parity */
56 #define LCR_PAR_ODD            0x08	/* Odd parity */
57 #define LCR_PAR_EVEN           0x18	/* Even parity */
58 #define LCR_PAR_MARK           0x28	/* Force parity bit to 1 */
59 #define LCR_PAR_SPACE          0x38	/* Force parity bit to 0 */
60 #define LCR_PAR_MASK           0x38	/* Mask for parity field */
61 
62 #define LCR_SET_BREAK          0x40	/* Set Break condition */
63 #define LCR_DL_ENABLE          0x80	/* Enable access to divisor latch */
64 
65 #define MCR_DTR                0x01	/* Assert DTR */
66 #define MCR_RTS                0x02	/* Assert RTS */
67 #define MCR_OUT1               0x04	/* Loopback only: Sets state of RI */
68 #define MCR_MASTER_IE          0x08	/* Enable interrupt outputs */
69 #define MCR_LOOPBACK           0x10	/* Set internal (digital) loopback mode */
70 #define MCR_XON_ANY            0x20	/* Enable any char to exit XOFF mode */
71 
72 #define MOS7840_MSR_CTS        0x10	/* Current state of CTS */
73 #define MOS7840_MSR_DSR        0x20	/* Current state of DSR */
74 #define MOS7840_MSR_RI         0x40	/* Current state of RI */
75 #define MOS7840_MSR_CD         0x80	/* Current state of CD */
76 
77 /*
78  * Defines used for sending commands to port
79  */
80 
81 #define MOS_WDR_TIMEOUT		5000	/* default urb timeout */
82 
83 #define MOS_PORT1       0x0200
84 #define MOS_PORT2       0x0300
85 #define MOS_VENREG      0x0000
86 #define MOS_MAX_PORT	0x02
87 #define MOS_WRITE       0x0E
88 #define MOS_READ        0x0D
89 
90 /* Requests */
91 #define MCS_RD_RTYPE    0xC0
92 #define MCS_WR_RTYPE    0x40
93 #define MCS_RDREQ       0x0D
94 #define MCS_WRREQ       0x0E
95 #define MCS_CTRL_TIMEOUT        500
96 #define VENDOR_READ_LENGTH      (0x01)
97 
98 #define MAX_NAME_LEN    64
99 
100 #define ZLP_REG1  0x3A		/* Zero_Flag_Reg1    58 */
101 #define ZLP_REG5  0x3E		/* Zero_Flag_Reg5    62 */
102 
103 /* For higher baud Rates use TIOCEXBAUD */
104 #define TIOCEXBAUD     0x5462
105 
106 /* vendor id and device id defines */
107 
108 /* The native mos7840/7820 component */
109 #define USB_VENDOR_ID_MOSCHIP           0x9710
110 #define MOSCHIP_DEVICE_ID_7840          0x7840
111 #define MOSCHIP_DEVICE_ID_7820          0x7820
112 #define MOSCHIP_DEVICE_ID_7810          0x7810
113 /* The native component can have its vendor/device id's overridden
114  * in vendor-specific implementations.  Such devices can be handled
115  * by making a change here, in id_table.
116  */
117 #define USB_VENDOR_ID_BANDB              0x0856
118 #define BANDB_DEVICE_ID_USO9ML2_2        0xAC22
119 #define BANDB_DEVICE_ID_USO9ML2_2P       0xBC00
120 #define BANDB_DEVICE_ID_USO9ML2_4        0xAC24
121 #define BANDB_DEVICE_ID_USO9ML2_4P       0xBC01
122 #define BANDB_DEVICE_ID_US9ML2_2         0xAC29
123 #define BANDB_DEVICE_ID_US9ML2_4         0xAC30
124 #define BANDB_DEVICE_ID_USPTL4_2         0xAC31
125 #define BANDB_DEVICE_ID_USPTL4_4         0xAC32
126 #define BANDB_DEVICE_ID_USOPTL4_2        0xAC42
127 #define BANDB_DEVICE_ID_USOPTL4_2P       0xBC02
128 #define BANDB_DEVICE_ID_USOPTL4_4        0xAC44
129 #define BANDB_DEVICE_ID_USOPTL4_4P       0xBC03
130 #define BANDB_DEVICE_ID_USOPTL2_4        0xAC24
131 
132 /* This driver also supports
133  * ATEN UC2324 device using Moschip MCS7840
134  * ATEN UC2322 device using Moschip MCS7820
135  */
136 #define USB_VENDOR_ID_ATENINTL		0x0557
137 #define ATENINTL_DEVICE_ID_UC2324	0x2011
138 #define ATENINTL_DEVICE_ID_UC2322	0x7820
139 
140 /* Interrupt Routine Defines    */
141 
142 #define SERIAL_IIR_RLS      0x06
143 #define SERIAL_IIR_MS       0x00
144 
145 /*
146  *  Emulation of the bit mask on the LINE STATUS REGISTER.
147  */
148 #define SERIAL_LSR_DR       0x0001
149 #define SERIAL_LSR_OE       0x0002
150 #define SERIAL_LSR_PE       0x0004
151 #define SERIAL_LSR_FE       0x0008
152 #define SERIAL_LSR_BI       0x0010
153 
154 #define MOS_MSR_DELTA_CTS   0x10
155 #define MOS_MSR_DELTA_DSR   0x20
156 #define MOS_MSR_DELTA_RI    0x40
157 #define MOS_MSR_DELTA_CD    0x80
158 
159 /* Serial Port register Address */
160 #define INTERRUPT_ENABLE_REGISTER  ((__u16)(0x01))
161 #define FIFO_CONTROL_REGISTER      ((__u16)(0x02))
162 #define LINE_CONTROL_REGISTER      ((__u16)(0x03))
163 #define MODEM_CONTROL_REGISTER     ((__u16)(0x04))
164 #define LINE_STATUS_REGISTER       ((__u16)(0x05))
165 #define MODEM_STATUS_REGISTER      ((__u16)(0x06))
166 #define SCRATCH_PAD_REGISTER       ((__u16)(0x07))
167 #define DIVISOR_LATCH_LSB          ((__u16)(0x00))
168 #define DIVISOR_LATCH_MSB          ((__u16)(0x01))
169 
170 #define CLK_MULTI_REGISTER         ((__u16)(0x02))
171 #define CLK_START_VALUE_REGISTER   ((__u16)(0x03))
172 #define GPIO_REGISTER              ((__u16)(0x07))
173 
174 #define SERIAL_LCR_DLAB            ((__u16)(0x0080))
175 
176 /*
177  * URB POOL related defines
178  */
179 #define NUM_URBS                        16	/* URB Count */
180 #define URB_TRANSFER_BUFFER_SIZE        32	/* URB Size  */
181 
182 /* LED on/off milliseconds*/
183 #define LED_ON_MS	500
184 #define LED_OFF_MS	500
185 
186 enum mos7840_flag {
187 	MOS7840_FLAG_CTRL_BUSY,
188 	MOS7840_FLAG_LED_BUSY,
189 };
190 
191 static const struct usb_device_id id_table[] = {
192 	{USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7840)},
193 	{USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7820)},
194 	{USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7810)},
195 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_2)},
196 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_2P)},
197 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_4)},
198 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USO9ML2_4P)},
199 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_US9ML2_2)},
200 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_US9ML2_4)},
201 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USPTL4_2)},
202 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USPTL4_4)},
203 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_2)},
204 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_2P)},
205 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_4)},
206 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL4_4P)},
207 	{USB_DEVICE(USB_VENDOR_ID_BANDB, BANDB_DEVICE_ID_USOPTL2_4)},
208 	{USB_DEVICE(USB_VENDOR_ID_ATENINTL, ATENINTL_DEVICE_ID_UC2324)},
209 	{USB_DEVICE(USB_VENDOR_ID_ATENINTL, ATENINTL_DEVICE_ID_UC2322)},
210 	{}			/* terminating entry */
211 };
212 MODULE_DEVICE_TABLE(usb, id_table);
213 
214 /* This structure holds all of the local port information */
215 
216 struct moschip_port {
217 	int port_num;		/*Actual port number in the device(1,2,etc) */
218 	struct urb *write_urb;	/* write URB for this port */
219 	struct urb *read_urb;	/* read URB for this port */
220 	__u8 shadowLCR;		/* last LCR value received */
221 	__u8 shadowMCR;		/* last MCR value received */
222 	char open;
223 	char open_ports;
224 	wait_queue_head_t wait_chase;	/* for handling sleeping while waiting for chase to finish */
225 	struct usb_serial_port *port;	/* loop back to the owner of this object */
226 
227 	/* Offsets */
228 	__u8 SpRegOffset;
229 	__u8 ControlRegOffset;
230 	__u8 DcrRegOffset;
231 	/* for processing control URBS in interrupt context */
232 	struct urb *control_urb;
233 	struct usb_ctrlrequest *dr;
234 	char *ctrl_buf;
235 	int MsrLsr;
236 
237 	spinlock_t pool_lock;
238 	struct urb *write_urb_pool[NUM_URBS];
239 	char busy[NUM_URBS];
240 	bool read_urb_busy;
241 
242 	/* For device(s) with LED indicator */
243 	bool has_led;
244 	struct timer_list led_timer1;	/* Timer for LED on */
245 	struct timer_list led_timer2;	/* Timer for LED off */
246 	struct urb *led_urb;
247 	struct usb_ctrlrequest *led_dr;
248 
249 	unsigned long flags;
250 };
251 
252 /*
253  * mos7840_set_reg_sync
254  * 	To set the Control register by calling usb_fill_control_urb function
255  *	by passing usb_sndctrlpipe function as parameter.
256  */
257 
258 static int mos7840_set_reg_sync(struct usb_serial_port *port, __u16 reg,
259 				__u16 val)
260 {
261 	struct usb_device *dev = port->serial->dev;
262 	val = val & 0x00ff;
263 	dev_dbg(&port->dev, "mos7840_set_reg_sync offset is %x, value %x\n", reg, val);
264 
265 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
266 			       MCS_WR_RTYPE, val, reg, NULL, 0,
267 			       MOS_WDR_TIMEOUT);
268 }
269 
270 /*
271  * mos7840_get_reg_sync
272  * 	To set the Uart register by calling usb_fill_control_urb function by
273  *	passing usb_rcvctrlpipe function as parameter.
274  */
275 
276 static int mos7840_get_reg_sync(struct usb_serial_port *port, __u16 reg,
277 				__u16 *val)
278 {
279 	struct usb_device *dev = port->serial->dev;
280 	int ret = 0;
281 	u8 *buf;
282 
283 	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
284 	if (!buf)
285 		return -ENOMEM;
286 
287 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
288 			      MCS_RD_RTYPE, 0, reg, buf, VENDOR_READ_LENGTH,
289 			      MOS_WDR_TIMEOUT);
290 	*val = buf[0];
291 	dev_dbg(&port->dev, "%s offset is %x, return val %x\n", __func__, reg, *val);
292 
293 	kfree(buf);
294 	return ret;
295 }
296 
297 /*
298  * mos7840_set_uart_reg
299  *	To set the Uart register by calling usb_fill_control_urb function by
300  *	passing usb_sndctrlpipe function as parameter.
301  */
302 
303 static int mos7840_set_uart_reg(struct usb_serial_port *port, __u16 reg,
304 				__u16 val)
305 {
306 
307 	struct usb_device *dev = port->serial->dev;
308 	val = val & 0x00ff;
309 	/* For the UART control registers, the application number need
310 	   to be Or'ed */
311 	if (port->serial->num_ports == 4) {
312 		val |= ((__u16)port->port_number + 1) << 8;
313 	} else {
314 		if (port->port_number == 0) {
315 			val |= ((__u16)port->port_number + 1) << 8;
316 		} else {
317 			val |= ((__u16)port->port_number + 2) << 8;
318 		}
319 	}
320 	dev_dbg(&port->dev, "%s application number is %x\n", __func__, val);
321 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ,
322 			       MCS_WR_RTYPE, val, reg, NULL, 0,
323 			       MOS_WDR_TIMEOUT);
324 
325 }
326 
327 /*
328  * mos7840_get_uart_reg
329  *	To set the Control register by calling usb_fill_control_urb function
330  *	by passing usb_rcvctrlpipe function as parameter.
331  */
332 static int mos7840_get_uart_reg(struct usb_serial_port *port, __u16 reg,
333 				__u16 *val)
334 {
335 	struct usb_device *dev = port->serial->dev;
336 	int ret = 0;
337 	__u16 Wval;
338 	u8 *buf;
339 
340 	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
341 	if (!buf)
342 		return -ENOMEM;
343 
344 	/* Wval  is same as application number */
345 	if (port->serial->num_ports == 4) {
346 		Wval = ((__u16)port->port_number + 1) << 8;
347 	} else {
348 		if (port->port_number == 0) {
349 			Wval = ((__u16)port->port_number + 1) << 8;
350 		} else {
351 			Wval = ((__u16)port->port_number + 2) << 8;
352 		}
353 	}
354 	dev_dbg(&port->dev, "%s application number is %x\n", __func__, Wval);
355 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), MCS_RDREQ,
356 			      MCS_RD_RTYPE, Wval, reg, buf, VENDOR_READ_LENGTH,
357 			      MOS_WDR_TIMEOUT);
358 	*val = buf[0];
359 
360 	kfree(buf);
361 	return ret;
362 }
363 
364 static void mos7840_dump_serial_port(struct usb_serial_port *port,
365 				     struct moschip_port *mos7840_port)
366 {
367 
368 	dev_dbg(&port->dev, "SpRegOffset is %2x\n", mos7840_port->SpRegOffset);
369 	dev_dbg(&port->dev, "ControlRegOffset is %2x\n", mos7840_port->ControlRegOffset);
370 	dev_dbg(&port->dev, "DCRRegOffset is %2x\n", mos7840_port->DcrRegOffset);
371 
372 }
373 
374 /************************************************************************/
375 /************************************************************************/
376 /*             I N T E R F A C E   F U N C T I O N S			*/
377 /*             I N T E R F A C E   F U N C T I O N S			*/
378 /************************************************************************/
379 /************************************************************************/
380 
381 static inline void mos7840_set_port_private(struct usb_serial_port *port,
382 					    struct moschip_port *data)
383 {
384 	usb_set_serial_port_data(port, (void *)data);
385 }
386 
387 static inline struct moschip_port *mos7840_get_port_private(struct
388 							    usb_serial_port
389 							    *port)
390 {
391 	return (struct moschip_port *)usb_get_serial_port_data(port);
392 }
393 
394 static void mos7840_handle_new_msr(struct moschip_port *port, __u8 new_msr)
395 {
396 	struct moschip_port *mos7840_port;
397 	struct async_icount *icount;
398 	mos7840_port = port;
399 	if (new_msr &
400 	    (MOS_MSR_DELTA_CTS | MOS_MSR_DELTA_DSR | MOS_MSR_DELTA_RI |
401 	     MOS_MSR_DELTA_CD)) {
402 		icount = &mos7840_port->port->icount;
403 
404 		/* update input line counters */
405 		if (new_msr & MOS_MSR_DELTA_CTS)
406 			icount->cts++;
407 		if (new_msr & MOS_MSR_DELTA_DSR)
408 			icount->dsr++;
409 		if (new_msr & MOS_MSR_DELTA_CD)
410 			icount->dcd++;
411 		if (new_msr & MOS_MSR_DELTA_RI)
412 			icount->rng++;
413 
414 		wake_up_interruptible(&port->port->port.delta_msr_wait);
415 	}
416 }
417 
418 static void mos7840_handle_new_lsr(struct moschip_port *port, __u8 new_lsr)
419 {
420 	struct async_icount *icount;
421 
422 	if (new_lsr & SERIAL_LSR_BI) {
423 		/*
424 		 * Parity and Framing errors only count if they
425 		 * occur exclusive of a break being
426 		 * received.
427 		 */
428 		new_lsr &= (__u8) (SERIAL_LSR_OE | SERIAL_LSR_BI);
429 	}
430 
431 	/* update input line counters */
432 	icount = &port->port->icount;
433 	if (new_lsr & SERIAL_LSR_BI)
434 		icount->brk++;
435 	if (new_lsr & SERIAL_LSR_OE)
436 		icount->overrun++;
437 	if (new_lsr & SERIAL_LSR_PE)
438 		icount->parity++;
439 	if (new_lsr & SERIAL_LSR_FE)
440 		icount->frame++;
441 }
442 
443 /************************************************************************/
444 /************************************************************************/
445 /*            U S B  C A L L B A C K   F U N C T I O N S                */
446 /*            U S B  C A L L B A C K   F U N C T I O N S                */
447 /************************************************************************/
448 /************************************************************************/
449 
450 static void mos7840_control_callback(struct urb *urb)
451 {
452 	unsigned char *data;
453 	struct moschip_port *mos7840_port;
454 	struct device *dev = &urb->dev->dev;
455 	__u8 regval = 0x0;
456 	int status = urb->status;
457 
458 	mos7840_port = urb->context;
459 
460 	switch (status) {
461 	case 0:
462 		/* success */
463 		break;
464 	case -ECONNRESET:
465 	case -ENOENT:
466 	case -ESHUTDOWN:
467 		/* this urb is terminated, clean up */
468 		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
469 		goto out;
470 	default:
471 		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
472 		goto out;
473 	}
474 
475 	dev_dbg(dev, "%s urb buffer size is %d\n", __func__, urb->actual_length);
476 	dev_dbg(dev, "%s mos7840_port->MsrLsr is %d port %d\n", __func__,
477 		mos7840_port->MsrLsr, mos7840_port->port_num);
478 	data = urb->transfer_buffer;
479 	regval = (__u8) data[0];
480 	dev_dbg(dev, "%s data is %x\n", __func__, regval);
481 	if (mos7840_port->MsrLsr == 0)
482 		mos7840_handle_new_msr(mos7840_port, regval);
483 	else if (mos7840_port->MsrLsr == 1)
484 		mos7840_handle_new_lsr(mos7840_port, regval);
485 out:
486 	clear_bit_unlock(MOS7840_FLAG_CTRL_BUSY, &mos7840_port->flags);
487 }
488 
489 static int mos7840_get_reg(struct moschip_port *mcs, __u16 Wval, __u16 reg,
490 			   __u16 *val)
491 {
492 	struct usb_device *dev = mcs->port->serial->dev;
493 	struct usb_ctrlrequest *dr = mcs->dr;
494 	unsigned char *buffer = mcs->ctrl_buf;
495 	int ret;
496 
497 	if (test_and_set_bit_lock(MOS7840_FLAG_CTRL_BUSY, &mcs->flags))
498 		return -EBUSY;
499 
500 	dr->bRequestType = MCS_RD_RTYPE;
501 	dr->bRequest = MCS_RDREQ;
502 	dr->wValue = cpu_to_le16(Wval);	/* 0 */
503 	dr->wIndex = cpu_to_le16(reg);
504 	dr->wLength = cpu_to_le16(2);
505 
506 	usb_fill_control_urb(mcs->control_urb, dev, usb_rcvctrlpipe(dev, 0),
507 			     (unsigned char *)dr, buffer, 2,
508 			     mos7840_control_callback, mcs);
509 	mcs->control_urb->transfer_buffer_length = 2;
510 	ret = usb_submit_urb(mcs->control_urb, GFP_ATOMIC);
511 	if (ret)
512 		clear_bit_unlock(MOS7840_FLAG_CTRL_BUSY, &mcs->flags);
513 
514 	return ret;
515 }
516 
517 static void mos7840_set_led_callback(struct urb *urb)
518 {
519 	switch (urb->status) {
520 	case 0:
521 		/* Success */
522 		break;
523 	case -ECONNRESET:
524 	case -ENOENT:
525 	case -ESHUTDOWN:
526 		/* This urb is terminated, clean up */
527 		dev_dbg(&urb->dev->dev, "%s - urb shutting down with status: %d",
528 			__func__, urb->status);
529 		break;
530 	default:
531 		dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d",
532 			__func__, urb->status);
533 	}
534 }
535 
536 static void mos7840_set_led_async(struct moschip_port *mcs, __u16 wval,
537 				__u16 reg)
538 {
539 	struct usb_device *dev = mcs->port->serial->dev;
540 	struct usb_ctrlrequest *dr = mcs->led_dr;
541 
542 	dr->bRequestType = MCS_WR_RTYPE;
543 	dr->bRequest = MCS_WRREQ;
544 	dr->wValue = cpu_to_le16(wval);
545 	dr->wIndex = cpu_to_le16(reg);
546 	dr->wLength = cpu_to_le16(0);
547 
548 	usb_fill_control_urb(mcs->led_urb, dev, usb_sndctrlpipe(dev, 0),
549 		(unsigned char *)dr, NULL, 0, mos7840_set_led_callback, NULL);
550 
551 	usb_submit_urb(mcs->led_urb, GFP_ATOMIC);
552 }
553 
554 static void mos7840_set_led_sync(struct usb_serial_port *port, __u16 reg,
555 				__u16 val)
556 {
557 	struct usb_device *dev = port->serial->dev;
558 
559 	usb_control_msg(dev, usb_sndctrlpipe(dev, 0), MCS_WRREQ, MCS_WR_RTYPE,
560 			val, reg, NULL, 0, MOS_WDR_TIMEOUT);
561 }
562 
563 static void mos7840_led_off(unsigned long arg)
564 {
565 	struct moschip_port *mcs = (struct moschip_port *) arg;
566 
567 	/* Turn off LED */
568 	mos7840_set_led_async(mcs, 0x0300, MODEM_CONTROL_REGISTER);
569 	mod_timer(&mcs->led_timer2,
570 				jiffies + msecs_to_jiffies(LED_OFF_MS));
571 }
572 
573 static void mos7840_led_flag_off(unsigned long arg)
574 {
575 	struct moschip_port *mcs = (struct moschip_port *) arg;
576 
577 	clear_bit_unlock(MOS7840_FLAG_LED_BUSY, &mcs->flags);
578 }
579 
580 static void mos7840_led_activity(struct usb_serial_port *port)
581 {
582 	struct moschip_port *mos7840_port = usb_get_serial_port_data(port);
583 
584 	if (test_and_set_bit_lock(MOS7840_FLAG_LED_BUSY, &mos7840_port->flags))
585 		return;
586 
587 	mos7840_set_led_async(mos7840_port, 0x0301, MODEM_CONTROL_REGISTER);
588 	mod_timer(&mos7840_port->led_timer1,
589 				jiffies + msecs_to_jiffies(LED_ON_MS));
590 }
591 
592 /*****************************************************************************
593  * mos7840_interrupt_callback
594  *	this is the callback function for when we have received data on the
595  *	interrupt endpoint.
596  *****************************************************************************/
597 
598 static void mos7840_interrupt_callback(struct urb *urb)
599 {
600 	int result;
601 	int length;
602 	struct moschip_port *mos7840_port;
603 	struct usb_serial *serial;
604 	__u16 Data;
605 	unsigned char *data;
606 	__u8 sp[5], st;
607 	int i, rv = 0;
608 	__u16 wval, wreg = 0;
609 	int status = urb->status;
610 
611 	switch (status) {
612 	case 0:
613 		/* success */
614 		break;
615 	case -ECONNRESET:
616 	case -ENOENT:
617 	case -ESHUTDOWN:
618 		/* this urb is terminated, clean up */
619 		dev_dbg(&urb->dev->dev, "%s - urb shutting down with status: %d\n",
620 			__func__, status);
621 		return;
622 	default:
623 		dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n",
624 			__func__, status);
625 		goto exit;
626 	}
627 
628 	length = urb->actual_length;
629 	data = urb->transfer_buffer;
630 
631 	serial = urb->context;
632 
633 	/* Moschip get 5 bytes
634 	 * Byte 1 IIR Port 1 (port.number is 0)
635 	 * Byte 2 IIR Port 2 (port.number is 1)
636 	 * Byte 3 IIR Port 3 (port.number is 2)
637 	 * Byte 4 IIR Port 4 (port.number is 3)
638 	 * Byte 5 FIFO status for both */
639 
640 	if (length && length > 5) {
641 		dev_dbg(&urb->dev->dev, "%s", "Wrong data !!!\n");
642 		return;
643 	}
644 
645 	sp[0] = (__u8) data[0];
646 	sp[1] = (__u8) data[1];
647 	sp[2] = (__u8) data[2];
648 	sp[3] = (__u8) data[3];
649 	st = (__u8) data[4];
650 
651 	for (i = 0; i < serial->num_ports; i++) {
652 		mos7840_port = mos7840_get_port_private(serial->port[i]);
653 		wval = ((__u16)serial->port[i]->port_number + 1) << 8;
654 		if (mos7840_port->open) {
655 			if (sp[i] & 0x01) {
656 				dev_dbg(&urb->dev->dev, "SP%d No Interrupt !!!\n", i);
657 			} else {
658 				switch (sp[i] & 0x0f) {
659 				case SERIAL_IIR_RLS:
660 					dev_dbg(&urb->dev->dev, "Serial Port %d: Receiver status error or \n", i);
661 					dev_dbg(&urb->dev->dev, "address bit detected in 9-bit mode\n");
662 					mos7840_port->MsrLsr = 1;
663 					wreg = LINE_STATUS_REGISTER;
664 					break;
665 				case SERIAL_IIR_MS:
666 					dev_dbg(&urb->dev->dev, "Serial Port %d: Modem status change\n", i);
667 					mos7840_port->MsrLsr = 0;
668 					wreg = MODEM_STATUS_REGISTER;
669 					break;
670 				}
671 				rv = mos7840_get_reg(mos7840_port, wval, wreg, &Data);
672 			}
673 		}
674 	}
675 	if (!(rv < 0))
676 		/* the completion handler for the control urb will resubmit */
677 		return;
678 exit:
679 	result = usb_submit_urb(urb, GFP_ATOMIC);
680 	if (result) {
681 		dev_err(&urb->dev->dev,
682 			"%s - Error %d submitting interrupt urb\n",
683 			__func__, result);
684 	}
685 }
686 
687 static int mos7840_port_paranoia_check(struct usb_serial_port *port,
688 				       const char *function)
689 {
690 	if (!port) {
691 		pr_debug("%s - port == NULL\n", function);
692 		return -1;
693 	}
694 	if (!port->serial) {
695 		pr_debug("%s - port->serial == NULL\n", function);
696 		return -1;
697 	}
698 
699 	return 0;
700 }
701 
702 /* Inline functions to check the sanity of a pointer that is passed to us */
703 static int mos7840_serial_paranoia_check(struct usb_serial *serial,
704 					 const char *function)
705 {
706 	if (!serial) {
707 		pr_debug("%s - serial == NULL\n", function);
708 		return -1;
709 	}
710 	if (!serial->type) {
711 		pr_debug("%s - serial->type == NULL!\n", function);
712 		return -1;
713 	}
714 
715 	return 0;
716 }
717 
718 static struct usb_serial *mos7840_get_usb_serial(struct usb_serial_port *port,
719 						 const char *function)
720 {
721 	/* if no port was specified, or it fails a paranoia check */
722 	if (!port ||
723 	    mos7840_port_paranoia_check(port, function) ||
724 	    mos7840_serial_paranoia_check(port->serial, function)) {
725 		/* then say that we don't have a valid usb_serial thing,
726 		 * which will end up genrating -ENODEV return values */
727 		return NULL;
728 	}
729 
730 	return port->serial;
731 }
732 
733 /*****************************************************************************
734  * mos7840_bulk_in_callback
735  *	this is the callback function for when we have received data on the
736  *	bulk in endpoint.
737  *****************************************************************************/
738 
739 static void mos7840_bulk_in_callback(struct urb *urb)
740 {
741 	int retval;
742 	unsigned char *data;
743 	struct usb_serial *serial;
744 	struct usb_serial_port *port;
745 	struct moschip_port *mos7840_port;
746 	int status = urb->status;
747 
748 	mos7840_port = urb->context;
749 	if (!mos7840_port)
750 		return;
751 
752 	if (status) {
753 		dev_dbg(&urb->dev->dev, "nonzero read bulk status received: %d\n", status);
754 		mos7840_port->read_urb_busy = false;
755 		return;
756 	}
757 
758 	port = mos7840_port->port;
759 	if (mos7840_port_paranoia_check(port, __func__)) {
760 		mos7840_port->read_urb_busy = false;
761 		return;
762 	}
763 
764 	serial = mos7840_get_usb_serial(port, __func__);
765 	if (!serial) {
766 		mos7840_port->read_urb_busy = false;
767 		return;
768 	}
769 
770 	data = urb->transfer_buffer;
771 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
772 
773 	if (urb->actual_length) {
774 		struct tty_port *tport = &mos7840_port->port->port;
775 		tty_insert_flip_string(tport, data, urb->actual_length);
776 		tty_flip_buffer_push(tport);
777 		port->icount.rx += urb->actual_length;
778 		dev_dbg(&port->dev, "icount.rx is %d:\n", port->icount.rx);
779 	}
780 
781 	if (!mos7840_port->read_urb) {
782 		dev_dbg(&port->dev, "%s", "URB KILLED !!!\n");
783 		mos7840_port->read_urb_busy = false;
784 		return;
785 	}
786 
787 	if (mos7840_port->has_led)
788 		mos7840_led_activity(port);
789 
790 	mos7840_port->read_urb_busy = true;
791 	retval = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
792 
793 	if (retval) {
794 		dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, retval = %d\n", retval);
795 		mos7840_port->read_urb_busy = false;
796 	}
797 }
798 
799 /*****************************************************************************
800  * mos7840_bulk_out_data_callback
801  *	this is the callback function for when we have finished sending
802  *	serial data on the bulk out endpoint.
803  *****************************************************************************/
804 
805 static void mos7840_bulk_out_data_callback(struct urb *urb)
806 {
807 	struct moschip_port *mos7840_port;
808 	struct usb_serial_port *port;
809 	int status = urb->status;
810 	int i;
811 
812 	mos7840_port = urb->context;
813 	port = mos7840_port->port;
814 	spin_lock(&mos7840_port->pool_lock);
815 	for (i = 0; i < NUM_URBS; i++) {
816 		if (urb == mos7840_port->write_urb_pool[i]) {
817 			mos7840_port->busy[i] = 0;
818 			break;
819 		}
820 	}
821 	spin_unlock(&mos7840_port->pool_lock);
822 
823 	if (status) {
824 		dev_dbg(&port->dev, "nonzero write bulk status received:%d\n", status);
825 		return;
826 	}
827 
828 	if (mos7840_port_paranoia_check(port, __func__))
829 		return;
830 
831 	if (mos7840_port->open)
832 		tty_port_tty_wakeup(&port->port);
833 
834 }
835 
836 /************************************************************************/
837 /*       D R I V E R  T T Y  I N T E R F A C E  F U N C T I O N S       */
838 /************************************************************************/
839 
840 /*****************************************************************************
841  * mos7840_open
842  *	this function is called by the tty driver when a port is opened
843  *	If successful, we return 0
844  *	Otherwise we return a negative error number.
845  *****************************************************************************/
846 
847 static int mos7840_open(struct tty_struct *tty, struct usb_serial_port *port)
848 {
849 	int response;
850 	int j;
851 	struct usb_serial *serial;
852 	struct urb *urb;
853 	__u16 Data;
854 	int status;
855 	struct moschip_port *mos7840_port;
856 	struct moschip_port *port0;
857 
858 	if (mos7840_port_paranoia_check(port, __func__))
859 		return -ENODEV;
860 
861 	serial = port->serial;
862 
863 	if (mos7840_serial_paranoia_check(serial, __func__))
864 		return -ENODEV;
865 
866 	mos7840_port = mos7840_get_port_private(port);
867 	port0 = mos7840_get_port_private(serial->port[0]);
868 
869 	if (mos7840_port == NULL || port0 == NULL)
870 		return -ENODEV;
871 
872 	usb_clear_halt(serial->dev, port->write_urb->pipe);
873 	usb_clear_halt(serial->dev, port->read_urb->pipe);
874 	port0->open_ports++;
875 
876 	/* Initialising the write urb pool */
877 	for (j = 0; j < NUM_URBS; ++j) {
878 		urb = usb_alloc_urb(0, GFP_KERNEL);
879 		mos7840_port->write_urb_pool[j] = urb;
880 
881 		if (urb == NULL) {
882 			dev_err(&port->dev, "No more urbs???\n");
883 			continue;
884 		}
885 
886 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
887 								GFP_KERNEL);
888 		if (!urb->transfer_buffer) {
889 			usb_free_urb(urb);
890 			mos7840_port->write_urb_pool[j] = NULL;
891 			dev_err(&port->dev,
892 				"%s-out of memory for urb buffers.\n",
893 				__func__);
894 			continue;
895 		}
896 	}
897 
898 /*****************************************************************************
899  * Initialize MCS7840 -- Write Init values to corresponding Registers
900  *
901  * Register Index
902  * 1 : IER
903  * 2 : FCR
904  * 3 : LCR
905  * 4 : MCR
906  *
907  * 0x08 : SP1/2 Control Reg
908  *****************************************************************************/
909 
910 	/* NEED to check the following Block */
911 
912 	Data = 0x0;
913 	status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);
914 	if (status < 0) {
915 		dev_dbg(&port->dev, "Reading Spreg failed\n");
916 		goto err;
917 	}
918 	Data |= 0x80;
919 	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
920 	if (status < 0) {
921 		dev_dbg(&port->dev, "writing Spreg failed\n");
922 		goto err;
923 	}
924 
925 	Data &= ~0x80;
926 	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
927 	if (status < 0) {
928 		dev_dbg(&port->dev, "writing Spreg failed\n");
929 		goto err;
930 	}
931 	/* End of block to be checked */
932 
933 	Data = 0x0;
934 	status = mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset,
935 									&Data);
936 	if (status < 0) {
937 		dev_dbg(&port->dev, "Reading Controlreg failed\n");
938 		goto err;
939 	}
940 	Data |= 0x08;		/* Driver done bit */
941 	Data |= 0x20;		/* rx_disable */
942 	status = mos7840_set_reg_sync(port,
943 				mos7840_port->ControlRegOffset, Data);
944 	if (status < 0) {
945 		dev_dbg(&port->dev, "writing Controlreg failed\n");
946 		goto err;
947 	}
948 	/* do register settings here */
949 	/* Set all regs to the device default values. */
950 	/***********************************
951 	 * First Disable all interrupts.
952 	 ***********************************/
953 	Data = 0x00;
954 	status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
955 	if (status < 0) {
956 		dev_dbg(&port->dev, "disabling interrupts failed\n");
957 		goto err;
958 	}
959 	/* Set FIFO_CONTROL_REGISTER to the default value */
960 	Data = 0x00;
961 	status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
962 	if (status < 0) {
963 		dev_dbg(&port->dev, "Writing FIFO_CONTROL_REGISTER  failed\n");
964 		goto err;
965 	}
966 
967 	Data = 0xcf;
968 	status = mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
969 	if (status < 0) {
970 		dev_dbg(&port->dev, "Writing FIFO_CONTROL_REGISTER  failed\n");
971 		goto err;
972 	}
973 
974 	Data = 0x03;
975 	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
976 	mos7840_port->shadowLCR = Data;
977 
978 	Data = 0x0b;
979 	status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
980 	mos7840_port->shadowMCR = Data;
981 
982 	Data = 0x00;
983 	status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
984 	mos7840_port->shadowLCR = Data;
985 
986 	Data |= SERIAL_LCR_DLAB;	/* data latch enable in LCR 0x80 */
987 	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
988 
989 	Data = 0x0c;
990 	status = mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);
991 
992 	Data = 0x0;
993 	status = mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);
994 
995 	Data = 0x00;
996 	status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
997 
998 	Data = Data & ~SERIAL_LCR_DLAB;
999 	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
1000 	mos7840_port->shadowLCR = Data;
1001 
1002 	/* clearing Bulkin and Bulkout Fifo */
1003 	Data = 0x0;
1004 	status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset, &Data);
1005 
1006 	Data = Data | 0x0c;
1007 	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
1008 
1009 	Data = Data & ~0x0c;
1010 	status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset, Data);
1011 	/* Finally enable all interrupts */
1012 	Data = 0x0c;
1013 	status = mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
1014 
1015 	/* clearing rx_disable */
1016 	Data = 0x0;
1017 	status = mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset,
1018 									&Data);
1019 	Data = Data & ~0x20;
1020 	status = mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset,
1021 									Data);
1022 
1023 	/* rx_negate */
1024 	Data = 0x0;
1025 	status = mos7840_get_reg_sync(port, mos7840_port->ControlRegOffset,
1026 									&Data);
1027 	Data = Data | 0x10;
1028 	status = mos7840_set_reg_sync(port, mos7840_port->ControlRegOffset,
1029 									Data);
1030 
1031 	/* Check to see if we've set up our endpoint info yet    *
1032 	 * (can't set it up in mos7840_startup as the structures *
1033 	 * were not set up at that time.)                        */
1034 	if (port0->open_ports == 1) {
1035 		if (serial->port[0]->interrupt_in_buffer == NULL) {
1036 			/* set up interrupt urb */
1037 			usb_fill_int_urb(serial->port[0]->interrupt_in_urb,
1038 				serial->dev,
1039 				usb_rcvintpipe(serial->dev,
1040 				serial->port[0]->interrupt_in_endpointAddress),
1041 				serial->port[0]->interrupt_in_buffer,
1042 				serial->port[0]->interrupt_in_urb->
1043 				transfer_buffer_length,
1044 				mos7840_interrupt_callback,
1045 				serial,
1046 				serial->port[0]->interrupt_in_urb->interval);
1047 
1048 			/* start interrupt read for mos7840               *
1049 			 * will continue as long as mos7840 is connected  */
1050 
1051 			response =
1052 			    usb_submit_urb(serial->port[0]->interrupt_in_urb,
1053 					   GFP_KERNEL);
1054 			if (response) {
1055 				dev_err(&port->dev, "%s - Error %d submitting "
1056 					"interrupt urb\n", __func__, response);
1057 			}
1058 
1059 		}
1060 
1061 	}
1062 
1063 	/* see if we've set up our endpoint info yet   *
1064 	 * (can't set it up in mos7840_startup as the  *
1065 	 * structures were not set up at that time.)   */
1066 
1067 	dev_dbg(&port->dev, "port number is %d\n", port->port_number);
1068 	dev_dbg(&port->dev, "minor number is %d\n", port->minor);
1069 	dev_dbg(&port->dev, "Bulkin endpoint is %d\n", port->bulk_in_endpointAddress);
1070 	dev_dbg(&port->dev, "BulkOut endpoint is %d\n", port->bulk_out_endpointAddress);
1071 	dev_dbg(&port->dev, "Interrupt endpoint is %d\n", port->interrupt_in_endpointAddress);
1072 	dev_dbg(&port->dev, "port's number in the device is %d\n", mos7840_port->port_num);
1073 	mos7840_port->read_urb = port->read_urb;
1074 
1075 	/* set up our bulk in urb */
1076 	if ((serial->num_ports == 2) && (((__u16)port->port_number % 2) != 0)) {
1077 		usb_fill_bulk_urb(mos7840_port->read_urb,
1078 			serial->dev,
1079 			usb_rcvbulkpipe(serial->dev,
1080 				(port->bulk_in_endpointAddress) + 2),
1081 			port->bulk_in_buffer,
1082 			mos7840_port->read_urb->transfer_buffer_length,
1083 			mos7840_bulk_in_callback, mos7840_port);
1084 	} else {
1085 		usb_fill_bulk_urb(mos7840_port->read_urb,
1086 			serial->dev,
1087 			usb_rcvbulkpipe(serial->dev,
1088 				port->bulk_in_endpointAddress),
1089 			port->bulk_in_buffer,
1090 			mos7840_port->read_urb->transfer_buffer_length,
1091 			mos7840_bulk_in_callback, mos7840_port);
1092 	}
1093 
1094 	dev_dbg(&port->dev, "%s: bulkin endpoint is %d\n", __func__, port->bulk_in_endpointAddress);
1095 	mos7840_port->read_urb_busy = true;
1096 	response = usb_submit_urb(mos7840_port->read_urb, GFP_KERNEL);
1097 	if (response) {
1098 		dev_err(&port->dev, "%s - Error %d submitting control urb\n",
1099 			__func__, response);
1100 		mos7840_port->read_urb_busy = false;
1101 	}
1102 
1103 	/* initialize our wait queues */
1104 	init_waitqueue_head(&mos7840_port->wait_chase);
1105 
1106 	/* initialize our port settings */
1107 	/* Must set to enable ints! */
1108 	mos7840_port->shadowMCR = MCR_MASTER_IE;
1109 	/* send a open port command */
1110 	mos7840_port->open = 1;
1111 	/* mos7840_change_port_settings(mos7840_port,old_termios); */
1112 
1113 	return 0;
1114 err:
1115 	for (j = 0; j < NUM_URBS; ++j) {
1116 		urb = mos7840_port->write_urb_pool[j];
1117 		if (!urb)
1118 			continue;
1119 		kfree(urb->transfer_buffer);
1120 		usb_free_urb(urb);
1121 	}
1122 	return status;
1123 }
1124 
1125 /*****************************************************************************
1126  * mos7840_chars_in_buffer
1127  *	this function is called by the tty driver when it wants to know how many
1128  *	bytes of data we currently have outstanding in the port (data that has
1129  *	been written, but hasn't made it out the port yet)
1130  *	If successful, we return the number of bytes left to be written in the
1131  *	system,
1132  *	Otherwise we return zero.
1133  *****************************************************************************/
1134 
1135 static int mos7840_chars_in_buffer(struct tty_struct *tty)
1136 {
1137 	struct usb_serial_port *port = tty->driver_data;
1138 	int i;
1139 	int chars = 0;
1140 	unsigned long flags;
1141 	struct moschip_port *mos7840_port;
1142 
1143 	if (mos7840_port_paranoia_check(port, __func__))
1144 		return 0;
1145 
1146 	mos7840_port = mos7840_get_port_private(port);
1147 	if (mos7840_port == NULL)
1148 		return 0;
1149 
1150 	spin_lock_irqsave(&mos7840_port->pool_lock, flags);
1151 	for (i = 0; i < NUM_URBS; ++i) {
1152 		if (mos7840_port->busy[i]) {
1153 			struct urb *urb = mos7840_port->write_urb_pool[i];
1154 			chars += urb->transfer_buffer_length;
1155 		}
1156 	}
1157 	spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
1158 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
1159 	return chars;
1160 
1161 }
1162 
1163 /*****************************************************************************
1164  * mos7840_close
1165  *	this function is called by the tty driver when a port is closed
1166  *****************************************************************************/
1167 
1168 static void mos7840_close(struct usb_serial_port *port)
1169 {
1170 	struct usb_serial *serial;
1171 	struct moschip_port *mos7840_port;
1172 	struct moschip_port *port0;
1173 	int j;
1174 	__u16 Data;
1175 
1176 	if (mos7840_port_paranoia_check(port, __func__))
1177 		return;
1178 
1179 	serial = mos7840_get_usb_serial(port, __func__);
1180 	if (!serial)
1181 		return;
1182 
1183 	mos7840_port = mos7840_get_port_private(port);
1184 	port0 = mos7840_get_port_private(serial->port[0]);
1185 
1186 	if (mos7840_port == NULL || port0 == NULL)
1187 		return;
1188 
1189 	for (j = 0; j < NUM_URBS; ++j)
1190 		usb_kill_urb(mos7840_port->write_urb_pool[j]);
1191 
1192 	/* Freeing Write URBs */
1193 	for (j = 0; j < NUM_URBS; ++j) {
1194 		if (mos7840_port->write_urb_pool[j]) {
1195 			if (mos7840_port->write_urb_pool[j]->transfer_buffer)
1196 				kfree(mos7840_port->write_urb_pool[j]->
1197 				      transfer_buffer);
1198 
1199 			usb_free_urb(mos7840_port->write_urb_pool[j]);
1200 		}
1201 	}
1202 
1203 	usb_kill_urb(mos7840_port->write_urb);
1204 	usb_kill_urb(mos7840_port->read_urb);
1205 	mos7840_port->read_urb_busy = false;
1206 
1207 	port0->open_ports--;
1208 	dev_dbg(&port->dev, "%s in close%d\n", __func__, port0->open_ports);
1209 	if (port0->open_ports == 0) {
1210 		if (serial->port[0]->interrupt_in_urb) {
1211 			dev_dbg(&port->dev, "Shutdown interrupt_in_urb\n");
1212 			usb_kill_urb(serial->port[0]->interrupt_in_urb);
1213 		}
1214 	}
1215 
1216 	if (mos7840_port->write_urb) {
1217 		/* if this urb had a transfer buffer already (old tx) free it */
1218 		kfree(mos7840_port->write_urb->transfer_buffer);
1219 		usb_free_urb(mos7840_port->write_urb);
1220 	}
1221 
1222 	Data = 0x0;
1223 	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
1224 
1225 	Data = 0x00;
1226 	mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
1227 
1228 	mos7840_port->open = 0;
1229 }
1230 
1231 /************************************************************************
1232  *
1233  * mos7840_block_until_chase_response
1234  *
1235  *	This function will block the close until one of the following:
1236  *		1. Response to our Chase comes from mos7840
1237  *		2. A timeout of 10 seconds without activity has expired
1238  *		   (1K of mos7840 data @ 2400 baud ==> 4 sec to empty)
1239  *
1240  ************************************************************************/
1241 
1242 static void mos7840_block_until_chase_response(struct tty_struct *tty,
1243 					struct moschip_port *mos7840_port)
1244 {
1245 	int timeout = msecs_to_jiffies(1000);
1246 	int wait = 10;
1247 	int count;
1248 
1249 	while (1) {
1250 		count = mos7840_chars_in_buffer(tty);
1251 
1252 		/* Check for Buffer status */
1253 		if (count <= 0)
1254 			return;
1255 
1256 		/* Block the thread for a while */
1257 		interruptible_sleep_on_timeout(&mos7840_port->wait_chase,
1258 					       timeout);
1259 		/* No activity.. count down section */
1260 		wait--;
1261 		if (wait == 0) {
1262 			dev_dbg(&mos7840_port->port->dev, "%s - TIMEOUT\n", __func__);
1263 			return;
1264 		} else {
1265 			/* Reset timeout value back to seconds */
1266 			wait = 10;
1267 		}
1268 	}
1269 
1270 }
1271 
1272 /*****************************************************************************
1273  * mos7840_break
1274  *	this function sends a break to the port
1275  *****************************************************************************/
1276 static void mos7840_break(struct tty_struct *tty, int break_state)
1277 {
1278 	struct usb_serial_port *port = tty->driver_data;
1279 	unsigned char data;
1280 	struct usb_serial *serial;
1281 	struct moschip_port *mos7840_port;
1282 
1283 	if (mos7840_port_paranoia_check(port, __func__))
1284 		return;
1285 
1286 	serial = mos7840_get_usb_serial(port, __func__);
1287 	if (!serial)
1288 		return;
1289 
1290 	mos7840_port = mos7840_get_port_private(port);
1291 
1292 	if (mos7840_port == NULL)
1293 		return;
1294 
1295 	/* flush and block until tx is empty */
1296 	mos7840_block_until_chase_response(tty, mos7840_port);
1297 
1298 	if (break_state == -1)
1299 		data = mos7840_port->shadowLCR | LCR_SET_BREAK;
1300 	else
1301 		data = mos7840_port->shadowLCR & ~LCR_SET_BREAK;
1302 
1303 	/* FIXME: no locking on shadowLCR anywhere in driver */
1304 	mos7840_port->shadowLCR = data;
1305 	dev_dbg(&port->dev, "%s mos7840_port->shadowLCR is %x\n", __func__, mos7840_port->shadowLCR);
1306 	mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER,
1307 			     mos7840_port->shadowLCR);
1308 }
1309 
1310 /*****************************************************************************
1311  * mos7840_write_room
1312  *	this function is called by the tty driver when it wants to know how many
1313  *	bytes of data we can accept for a specific port.
1314  *	If successful, we return the amount of room that we have for this port
1315  *	Otherwise we return a negative error number.
1316  *****************************************************************************/
1317 
1318 static int mos7840_write_room(struct tty_struct *tty)
1319 {
1320 	struct usb_serial_port *port = tty->driver_data;
1321 	int i;
1322 	int room = 0;
1323 	unsigned long flags;
1324 	struct moschip_port *mos7840_port;
1325 
1326 	if (mos7840_port_paranoia_check(port, __func__))
1327 		return -1;
1328 
1329 	mos7840_port = mos7840_get_port_private(port);
1330 	if (mos7840_port == NULL)
1331 		return -1;
1332 
1333 	spin_lock_irqsave(&mos7840_port->pool_lock, flags);
1334 	for (i = 0; i < NUM_URBS; ++i) {
1335 		if (!mos7840_port->busy[i])
1336 			room += URB_TRANSFER_BUFFER_SIZE;
1337 	}
1338 	spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
1339 
1340 	room = (room == 0) ? 0 : room - URB_TRANSFER_BUFFER_SIZE + 1;
1341 	dev_dbg(&mos7840_port->port->dev, "%s - returns %d\n", __func__, room);
1342 	return room;
1343 
1344 }
1345 
1346 /*****************************************************************************
1347  * mos7840_write
1348  *	this function is called by the tty driver when data should be written to
1349  *	the port.
1350  *	If successful, we return the number of bytes written, otherwise we
1351  *      return a negative error number.
1352  *****************************************************************************/
1353 
1354 static int mos7840_write(struct tty_struct *tty, struct usb_serial_port *port,
1355 			 const unsigned char *data, int count)
1356 {
1357 	int status;
1358 	int i;
1359 	int bytes_sent = 0;
1360 	int transfer_size;
1361 	unsigned long flags;
1362 
1363 	struct moschip_port *mos7840_port;
1364 	struct usb_serial *serial;
1365 	struct urb *urb;
1366 	/* __u16 Data; */
1367 	const unsigned char *current_position = data;
1368 	unsigned char *data1;
1369 
1370 #ifdef NOTMOS7840
1371 	Data = 0x00;
1372 	status = mos7840_get_uart_reg(port, LINE_CONTROL_REGISTER, &Data);
1373 	mos7840_port->shadowLCR = Data;
1374 	dev_dbg(&port->dev, "%s: LINE_CONTROL_REGISTER is %x\n", __func__, Data);
1375 	dev_dbg(&port->dev, "%s: mos7840_port->shadowLCR is %x\n", __func__, mos7840_port->shadowLCR);
1376 
1377 	/* Data = 0x03; */
1378 	/* status = mos7840_set_uart_reg(port,LINE_CONTROL_REGISTER,Data); */
1379 	/* mos7840_port->shadowLCR=Data;//Need to add later */
1380 
1381 	Data |= SERIAL_LCR_DLAB;	/* data latch enable in LCR 0x80 */
1382 	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
1383 
1384 	/* Data = 0x0c; */
1385 	/* status = mos7840_set_uart_reg(port,DIVISOR_LATCH_LSB,Data); */
1386 	Data = 0x00;
1387 	status = mos7840_get_uart_reg(port, DIVISOR_LATCH_LSB, &Data);
1388 	dev_dbg(&port->dev, "%s: DLL value is %x\n", __func__, Data);
1389 
1390 	Data = 0x0;
1391 	status = mos7840_get_uart_reg(port, DIVISOR_LATCH_MSB, &Data);
1392 	dev_dbg(&port->dev, "%s: DLM value is %x\n", __func__, Data);
1393 
1394 	Data = Data & ~SERIAL_LCR_DLAB;
1395 	dev_dbg(&port->dev, "%s: mos7840_port->shadowLCR is %x\n", __func__, mos7840_port->shadowLCR);
1396 	status = mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
1397 #endif
1398 
1399 	if (mos7840_port_paranoia_check(port, __func__))
1400 		return -1;
1401 
1402 	serial = port->serial;
1403 	if (mos7840_serial_paranoia_check(serial, __func__))
1404 		return -1;
1405 
1406 	mos7840_port = mos7840_get_port_private(port);
1407 	if (mos7840_port == NULL)
1408 		return -1;
1409 
1410 	/* try to find a free urb in the list */
1411 	urb = NULL;
1412 
1413 	spin_lock_irqsave(&mos7840_port->pool_lock, flags);
1414 	for (i = 0; i < NUM_URBS; ++i) {
1415 		if (!mos7840_port->busy[i]) {
1416 			mos7840_port->busy[i] = 1;
1417 			urb = mos7840_port->write_urb_pool[i];
1418 			dev_dbg(&port->dev, "URB:%d\n", i);
1419 			break;
1420 		}
1421 	}
1422 	spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
1423 
1424 	if (urb == NULL) {
1425 		dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
1426 		goto exit;
1427 	}
1428 
1429 	if (urb->transfer_buffer == NULL) {
1430 		urb->transfer_buffer =
1431 		    kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
1432 
1433 		if (urb->transfer_buffer == NULL) {
1434 			dev_err_console(port, "%s no more kernel memory...\n",
1435 				__func__);
1436 			goto exit;
1437 		}
1438 	}
1439 	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
1440 
1441 	memcpy(urb->transfer_buffer, current_position, transfer_size);
1442 
1443 	/* fill urb with data and submit  */
1444 	if ((serial->num_ports == 2) && (((__u16)port->port_number % 2) != 0)) {
1445 		usb_fill_bulk_urb(urb,
1446 			serial->dev,
1447 			usb_sndbulkpipe(serial->dev,
1448 				(port->bulk_out_endpointAddress) + 2),
1449 			urb->transfer_buffer,
1450 			transfer_size,
1451 			mos7840_bulk_out_data_callback, mos7840_port);
1452 	} else {
1453 		usb_fill_bulk_urb(urb,
1454 			serial->dev,
1455 			usb_sndbulkpipe(serial->dev,
1456 				port->bulk_out_endpointAddress),
1457 			urb->transfer_buffer,
1458 			transfer_size,
1459 			mos7840_bulk_out_data_callback, mos7840_port);
1460 	}
1461 
1462 	data1 = urb->transfer_buffer;
1463 	dev_dbg(&port->dev, "bulkout endpoint is %d\n", port->bulk_out_endpointAddress);
1464 
1465 	if (mos7840_port->has_led)
1466 		mos7840_led_activity(port);
1467 
1468 	/* send it down the pipe */
1469 	status = usb_submit_urb(urb, GFP_ATOMIC);
1470 
1471 	if (status) {
1472 		mos7840_port->busy[i] = 0;
1473 		dev_err_console(port, "%s - usb_submit_urb(write bulk) failed "
1474 			"with status = %d\n", __func__, status);
1475 		bytes_sent = status;
1476 		goto exit;
1477 	}
1478 	bytes_sent = transfer_size;
1479 	port->icount.tx += transfer_size;
1480 	dev_dbg(&port->dev, "icount.tx is %d:\n", port->icount.tx);
1481 exit:
1482 	return bytes_sent;
1483 
1484 }
1485 
1486 /*****************************************************************************
1487  * mos7840_throttle
1488  *	this function is called by the tty driver when it wants to stop the data
1489  *	being read from the port.
1490  *****************************************************************************/
1491 
1492 static void mos7840_throttle(struct tty_struct *tty)
1493 {
1494 	struct usb_serial_port *port = tty->driver_data;
1495 	struct moschip_port *mos7840_port;
1496 	int status;
1497 
1498 	if (mos7840_port_paranoia_check(port, __func__))
1499 		return;
1500 
1501 	mos7840_port = mos7840_get_port_private(port);
1502 
1503 	if (mos7840_port == NULL)
1504 		return;
1505 
1506 	if (!mos7840_port->open) {
1507 		dev_dbg(&port->dev, "%s", "port not opened\n");
1508 		return;
1509 	}
1510 
1511 	/* if we are implementing XON/XOFF, send the stop character */
1512 	if (I_IXOFF(tty)) {
1513 		unsigned char stop_char = STOP_CHAR(tty);
1514 		status = mos7840_write(tty, port, &stop_char, 1);
1515 		if (status <= 0)
1516 			return;
1517 	}
1518 	/* if we are implementing RTS/CTS, toggle that line */
1519 	if (tty->termios.c_cflag & CRTSCTS) {
1520 		mos7840_port->shadowMCR &= ~MCR_RTS;
1521 		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
1522 					 mos7840_port->shadowMCR);
1523 		if (status < 0)
1524 			return;
1525 	}
1526 }
1527 
1528 /*****************************************************************************
1529  * mos7840_unthrottle
1530  *	this function is called by the tty driver when it wants to resume
1531  *	the data being read from the port (called after mos7840_throttle is
1532  *	called)
1533  *****************************************************************************/
1534 static void mos7840_unthrottle(struct tty_struct *tty)
1535 {
1536 	struct usb_serial_port *port = tty->driver_data;
1537 	int status;
1538 	struct moschip_port *mos7840_port = mos7840_get_port_private(port);
1539 
1540 	if (mos7840_port_paranoia_check(port, __func__))
1541 		return;
1542 
1543 	if (mos7840_port == NULL)
1544 		return;
1545 
1546 	if (!mos7840_port->open) {
1547 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1548 		return;
1549 	}
1550 
1551 	/* if we are implementing XON/XOFF, send the start character */
1552 	if (I_IXOFF(tty)) {
1553 		unsigned char start_char = START_CHAR(tty);
1554 		status = mos7840_write(tty, port, &start_char, 1);
1555 		if (status <= 0)
1556 			return;
1557 	}
1558 
1559 	/* if we are implementing RTS/CTS, toggle that line */
1560 	if (tty->termios.c_cflag & CRTSCTS) {
1561 		mos7840_port->shadowMCR |= MCR_RTS;
1562 		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
1563 					 mos7840_port->shadowMCR);
1564 		if (status < 0)
1565 			return;
1566 	}
1567 }
1568 
1569 static int mos7840_tiocmget(struct tty_struct *tty)
1570 {
1571 	struct usb_serial_port *port = tty->driver_data;
1572 	struct moschip_port *mos7840_port;
1573 	unsigned int result;
1574 	__u16 msr;
1575 	__u16 mcr;
1576 	int status;
1577 	mos7840_port = mos7840_get_port_private(port);
1578 
1579 	if (mos7840_port == NULL)
1580 		return -ENODEV;
1581 
1582 	status = mos7840_get_uart_reg(port, MODEM_STATUS_REGISTER, &msr);
1583 	status = mos7840_get_uart_reg(port, MODEM_CONTROL_REGISTER, &mcr);
1584 	result = ((mcr & MCR_DTR) ? TIOCM_DTR : 0)
1585 	    | ((mcr & MCR_RTS) ? TIOCM_RTS : 0)
1586 	    | ((mcr & MCR_LOOPBACK) ? TIOCM_LOOP : 0)
1587 	    | ((msr & MOS7840_MSR_CTS) ? TIOCM_CTS : 0)
1588 	    | ((msr & MOS7840_MSR_CD) ? TIOCM_CAR : 0)
1589 	    | ((msr & MOS7840_MSR_RI) ? TIOCM_RI : 0)
1590 	    | ((msr & MOS7840_MSR_DSR) ? TIOCM_DSR : 0);
1591 
1592 	dev_dbg(&port->dev, "%s - 0x%04X\n", __func__, result);
1593 
1594 	return result;
1595 }
1596 
1597 static int mos7840_tiocmset(struct tty_struct *tty,
1598 			    unsigned int set, unsigned int clear)
1599 {
1600 	struct usb_serial_port *port = tty->driver_data;
1601 	struct moschip_port *mos7840_port;
1602 	unsigned int mcr;
1603 	int status;
1604 
1605 	mos7840_port = mos7840_get_port_private(port);
1606 
1607 	if (mos7840_port == NULL)
1608 		return -ENODEV;
1609 
1610 	/* FIXME: What locks the port registers ? */
1611 	mcr = mos7840_port->shadowMCR;
1612 	if (clear & TIOCM_RTS)
1613 		mcr &= ~MCR_RTS;
1614 	if (clear & TIOCM_DTR)
1615 		mcr &= ~MCR_DTR;
1616 	if (clear & TIOCM_LOOP)
1617 		mcr &= ~MCR_LOOPBACK;
1618 
1619 	if (set & TIOCM_RTS)
1620 		mcr |= MCR_RTS;
1621 	if (set & TIOCM_DTR)
1622 		mcr |= MCR_DTR;
1623 	if (set & TIOCM_LOOP)
1624 		mcr |= MCR_LOOPBACK;
1625 
1626 	mos7840_port->shadowMCR = mcr;
1627 
1628 	status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, mcr);
1629 	if (status < 0) {
1630 		dev_dbg(&port->dev, "setting MODEM_CONTROL_REGISTER Failed\n");
1631 		return status;
1632 	}
1633 
1634 	return 0;
1635 }
1636 
1637 /*****************************************************************************
1638  * mos7840_calc_baud_rate_divisor
1639  *	this function calculates the proper baud rate divisor for the specified
1640  *	baud rate.
1641  *****************************************************************************/
1642 static int mos7840_calc_baud_rate_divisor(struct usb_serial_port *port,
1643 					  int baudRate, int *divisor,
1644 					  __u16 *clk_sel_val)
1645 {
1646 	dev_dbg(&port->dev, "%s - %d\n", __func__, baudRate);
1647 
1648 	if (baudRate <= 115200) {
1649 		*divisor = 115200 / baudRate;
1650 		*clk_sel_val = 0x0;
1651 	}
1652 	if ((baudRate > 115200) && (baudRate <= 230400)) {
1653 		*divisor = 230400 / baudRate;
1654 		*clk_sel_val = 0x10;
1655 	} else if ((baudRate > 230400) && (baudRate <= 403200)) {
1656 		*divisor = 403200 / baudRate;
1657 		*clk_sel_val = 0x20;
1658 	} else if ((baudRate > 403200) && (baudRate <= 460800)) {
1659 		*divisor = 460800 / baudRate;
1660 		*clk_sel_val = 0x30;
1661 	} else if ((baudRate > 460800) && (baudRate <= 806400)) {
1662 		*divisor = 806400 / baudRate;
1663 		*clk_sel_val = 0x40;
1664 	} else if ((baudRate > 806400) && (baudRate <= 921600)) {
1665 		*divisor = 921600 / baudRate;
1666 		*clk_sel_val = 0x50;
1667 	} else if ((baudRate > 921600) && (baudRate <= 1572864)) {
1668 		*divisor = 1572864 / baudRate;
1669 		*clk_sel_val = 0x60;
1670 	} else if ((baudRate > 1572864) && (baudRate <= 3145728)) {
1671 		*divisor = 3145728 / baudRate;
1672 		*clk_sel_val = 0x70;
1673 	}
1674 	return 0;
1675 
1676 #ifdef NOTMCS7840
1677 
1678 	for (i = 0; i < ARRAY_SIZE(mos7840_divisor_table); i++) {
1679 		if (mos7840_divisor_table[i].BaudRate == baudrate) {
1680 			*divisor = mos7840_divisor_table[i].Divisor;
1681 			return 0;
1682 		}
1683 	}
1684 
1685 	/* After trying for all the standard baud rates    *
1686 	 * Try calculating the divisor for this baud rate  */
1687 
1688 	if (baudrate > 75 && baudrate < 230400) {
1689 		/* get the divisor */
1690 		custom = (__u16) (230400L / baudrate);
1691 
1692 		/* Check for round off */
1693 		round1 = (__u16) (2304000L / baudrate);
1694 		round = (__u16) (round1 - (custom * 10));
1695 		if (round > 4)
1696 			custom++;
1697 		*divisor = custom;
1698 
1699 		dev_dbg(&port->dev, " Baud %d = %d\n", baudrate, custom);
1700 		return 0;
1701 	}
1702 
1703 	dev_dbg(&port->dev, "%s", " Baud calculation Failed...\n");
1704 	return -1;
1705 #endif
1706 }
1707 
1708 /*****************************************************************************
1709  * mos7840_send_cmd_write_baud_rate
1710  *	this function sends the proper command to change the baud rate of the
1711  *	specified port.
1712  *****************************************************************************/
1713 
1714 static int mos7840_send_cmd_write_baud_rate(struct moschip_port *mos7840_port,
1715 					    int baudRate)
1716 {
1717 	int divisor = 0;
1718 	int status;
1719 	__u16 Data;
1720 	unsigned char number;
1721 	__u16 clk_sel_val;
1722 	struct usb_serial_port *port;
1723 
1724 	if (mos7840_port == NULL)
1725 		return -1;
1726 
1727 	port = mos7840_port->port;
1728 	if (mos7840_port_paranoia_check(port, __func__))
1729 		return -1;
1730 
1731 	if (mos7840_serial_paranoia_check(port->serial, __func__))
1732 		return -1;
1733 
1734 	number = mos7840_port->port->port_number;
1735 
1736 	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudRate);
1737 	/* reset clk_uart_sel in spregOffset */
1738 	if (baudRate > 115200) {
1739 #ifdef HW_flow_control
1740 		/* NOTE: need to see the pther register to modify */
1741 		/* setting h/w flow control bit to 1 */
1742 		Data = 0x2b;
1743 		mos7840_port->shadowMCR = Data;
1744 		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
1745 									Data);
1746 		if (status < 0) {
1747 			dev_dbg(&port->dev, "Writing spreg failed in set_serial_baud\n");
1748 			return -1;
1749 		}
1750 #endif
1751 
1752 	} else {
1753 #ifdef HW_flow_control
1754 		/* setting h/w flow control bit to 0 */
1755 		Data = 0xb;
1756 		mos7840_port->shadowMCR = Data;
1757 		status = mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER,
1758 									Data);
1759 		if (status < 0) {
1760 			dev_dbg(&port->dev, "Writing spreg failed in set_serial_baud\n");
1761 			return -1;
1762 		}
1763 #endif
1764 
1765 	}
1766 
1767 	if (1) {		/* baudRate <= 115200) */
1768 		clk_sel_val = 0x0;
1769 		Data = 0x0;
1770 		status = mos7840_calc_baud_rate_divisor(port, baudRate, &divisor,
1771 						   &clk_sel_val);
1772 		status = mos7840_get_reg_sync(port, mos7840_port->SpRegOffset,
1773 								 &Data);
1774 		if (status < 0) {
1775 			dev_dbg(&port->dev, "reading spreg failed in set_serial_baud\n");
1776 			return -1;
1777 		}
1778 		Data = (Data & 0x8f) | clk_sel_val;
1779 		status = mos7840_set_reg_sync(port, mos7840_port->SpRegOffset,
1780 								Data);
1781 		if (status < 0) {
1782 			dev_dbg(&port->dev, "Writing spreg failed in set_serial_baud\n");
1783 			return -1;
1784 		}
1785 		/* Calculate the Divisor */
1786 
1787 		if (status) {
1788 			dev_err(&port->dev, "%s - bad baud rate\n", __func__);
1789 			return status;
1790 		}
1791 		/* Enable access to divisor latch */
1792 		Data = mos7840_port->shadowLCR | SERIAL_LCR_DLAB;
1793 		mos7840_port->shadowLCR = Data;
1794 		mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
1795 
1796 		/* Write the divisor */
1797 		Data = (unsigned char)(divisor & 0xff);
1798 		dev_dbg(&port->dev, "set_serial_baud Value to write DLL is %x\n", Data);
1799 		mos7840_set_uart_reg(port, DIVISOR_LATCH_LSB, Data);
1800 
1801 		Data = (unsigned char)((divisor & 0xff00) >> 8);
1802 		dev_dbg(&port->dev, "set_serial_baud Value to write DLM is %x\n", Data);
1803 		mos7840_set_uart_reg(port, DIVISOR_LATCH_MSB, Data);
1804 
1805 		/* Disable access to divisor latch */
1806 		Data = mos7840_port->shadowLCR & ~SERIAL_LCR_DLAB;
1807 		mos7840_port->shadowLCR = Data;
1808 		mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
1809 
1810 	}
1811 	return status;
1812 }
1813 
1814 /*****************************************************************************
1815  * mos7840_change_port_settings
1816  *	This routine is called to set the UART on the device to match
1817  *      the specified new settings.
1818  *****************************************************************************/
1819 
1820 static void mos7840_change_port_settings(struct tty_struct *tty,
1821 	struct moschip_port *mos7840_port, struct ktermios *old_termios)
1822 {
1823 	int baud;
1824 	unsigned cflag;
1825 	unsigned iflag;
1826 	__u8 lData;
1827 	__u8 lParity;
1828 	__u8 lStop;
1829 	int status;
1830 	__u16 Data;
1831 	struct usb_serial_port *port;
1832 	struct usb_serial *serial;
1833 
1834 	if (mos7840_port == NULL)
1835 		return;
1836 
1837 	port = mos7840_port->port;
1838 
1839 	if (mos7840_port_paranoia_check(port, __func__))
1840 		return;
1841 
1842 	if (mos7840_serial_paranoia_check(port->serial, __func__))
1843 		return;
1844 
1845 	serial = port->serial;
1846 
1847 	if (!mos7840_port->open) {
1848 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1849 		return;
1850 	}
1851 
1852 	lData = LCR_BITS_8;
1853 	lStop = LCR_STOP_1;
1854 	lParity = LCR_PAR_NONE;
1855 
1856 	cflag = tty->termios.c_cflag;
1857 	iflag = tty->termios.c_iflag;
1858 
1859 	/* Change the number of bits */
1860 	if (cflag & CSIZE) {
1861 		switch (cflag & CSIZE) {
1862 		case CS5:
1863 			lData = LCR_BITS_5;
1864 			break;
1865 
1866 		case CS6:
1867 			lData = LCR_BITS_6;
1868 			break;
1869 
1870 		case CS7:
1871 			lData = LCR_BITS_7;
1872 			break;
1873 		default:
1874 		case CS8:
1875 			lData = LCR_BITS_8;
1876 			break;
1877 		}
1878 	}
1879 	/* Change the Parity bit */
1880 	if (cflag & PARENB) {
1881 		if (cflag & PARODD) {
1882 			lParity = LCR_PAR_ODD;
1883 			dev_dbg(&port->dev, "%s - parity = odd\n", __func__);
1884 		} else {
1885 			lParity = LCR_PAR_EVEN;
1886 			dev_dbg(&port->dev, "%s - parity = even\n", __func__);
1887 		}
1888 
1889 	} else {
1890 		dev_dbg(&port->dev, "%s - parity = none\n", __func__);
1891 	}
1892 
1893 	if (cflag & CMSPAR)
1894 		lParity = lParity | 0x20;
1895 
1896 	/* Change the Stop bit */
1897 	if (cflag & CSTOPB) {
1898 		lStop = LCR_STOP_2;
1899 		dev_dbg(&port->dev, "%s - stop bits = 2\n", __func__);
1900 	} else {
1901 		lStop = LCR_STOP_1;
1902 		dev_dbg(&port->dev, "%s - stop bits = 1\n", __func__);
1903 	}
1904 
1905 	/* Update the LCR with the correct value */
1906 	mos7840_port->shadowLCR &=
1907 	    ~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
1908 	mos7840_port->shadowLCR |= (lData | lParity | lStop);
1909 
1910 	dev_dbg(&port->dev, "%s - mos7840_port->shadowLCR is %x\n", __func__,
1911 		mos7840_port->shadowLCR);
1912 	/* Disable Interrupts */
1913 	Data = 0x00;
1914 	mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
1915 
1916 	Data = 0x00;
1917 	mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
1918 
1919 	Data = 0xcf;
1920 	mos7840_set_uart_reg(port, FIFO_CONTROL_REGISTER, Data);
1921 
1922 	/* Send the updated LCR value to the mos7840 */
1923 	Data = mos7840_port->shadowLCR;
1924 
1925 	mos7840_set_uart_reg(port, LINE_CONTROL_REGISTER, Data);
1926 
1927 	Data = 0x00b;
1928 	mos7840_port->shadowMCR = Data;
1929 	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
1930 	Data = 0x00b;
1931 	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
1932 
1933 	/* set up the MCR register and send it to the mos7840 */
1934 
1935 	mos7840_port->shadowMCR = MCR_MASTER_IE;
1936 	if (cflag & CBAUD)
1937 		mos7840_port->shadowMCR |= (MCR_DTR | MCR_RTS);
1938 
1939 	if (cflag & CRTSCTS)
1940 		mos7840_port->shadowMCR |= (MCR_XON_ANY);
1941 	else
1942 		mos7840_port->shadowMCR &= ~(MCR_XON_ANY);
1943 
1944 	Data = mos7840_port->shadowMCR;
1945 	mos7840_set_uart_reg(port, MODEM_CONTROL_REGISTER, Data);
1946 
1947 	/* Determine divisor based on baud rate */
1948 	baud = tty_get_baud_rate(tty);
1949 
1950 	if (!baud) {
1951 		/* pick a default, any default... */
1952 		dev_dbg(&port->dev, "%s", "Picked default baud...\n");
1953 		baud = 9600;
1954 	}
1955 
1956 	dev_dbg(&port->dev, "%s - baud rate = %d\n", __func__, baud);
1957 	status = mos7840_send_cmd_write_baud_rate(mos7840_port, baud);
1958 
1959 	/* Enable Interrupts */
1960 	Data = 0x0c;
1961 	mos7840_set_uart_reg(port, INTERRUPT_ENABLE_REGISTER, Data);
1962 
1963 	if (mos7840_port->read_urb_busy == false) {
1964 		mos7840_port->read_urb_busy = true;
1965 		status = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
1966 		if (status) {
1967 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n",
1968 			    status);
1969 			mos7840_port->read_urb_busy = false;
1970 		}
1971 	}
1972 	dev_dbg(&port->dev, "%s - mos7840_port->shadowLCR is End %x\n", __func__,
1973 		mos7840_port->shadowLCR);
1974 }
1975 
1976 /*****************************************************************************
1977  * mos7840_set_termios
1978  *	this function is called by the tty driver when it wants to change
1979  *	the termios structure
1980  *****************************************************************************/
1981 
1982 static void mos7840_set_termios(struct tty_struct *tty,
1983 				struct usb_serial_port *port,
1984 				struct ktermios *old_termios)
1985 {
1986 	int status;
1987 	unsigned int cflag;
1988 	struct usb_serial *serial;
1989 	struct moschip_port *mos7840_port;
1990 
1991 	if (mos7840_port_paranoia_check(port, __func__))
1992 		return;
1993 
1994 	serial = port->serial;
1995 
1996 	if (mos7840_serial_paranoia_check(serial, __func__))
1997 		return;
1998 
1999 	mos7840_port = mos7840_get_port_private(port);
2000 
2001 	if (mos7840_port == NULL)
2002 		return;
2003 
2004 	if (!mos7840_port->open) {
2005 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
2006 		return;
2007 	}
2008 
2009 	dev_dbg(&port->dev, "%s", "setting termios - \n");
2010 
2011 	cflag = tty->termios.c_cflag;
2012 
2013 	dev_dbg(&port->dev, "%s - clfag %08x iflag %08x\n", __func__,
2014 		tty->termios.c_cflag, RELEVANT_IFLAG(tty->termios.c_iflag));
2015 	dev_dbg(&port->dev, "%s - old clfag %08x old iflag %08x\n", __func__,
2016 		old_termios->c_cflag, RELEVANT_IFLAG(old_termios->c_iflag));
2017 
2018 	/* change the port settings to the new ones specified */
2019 
2020 	mos7840_change_port_settings(tty, mos7840_port, old_termios);
2021 
2022 	if (!mos7840_port->read_urb) {
2023 		dev_dbg(&port->dev, "%s", "URB KILLED !!!!!\n");
2024 		return;
2025 	}
2026 
2027 	if (mos7840_port->read_urb_busy == false) {
2028 		mos7840_port->read_urb_busy = true;
2029 		status = usb_submit_urb(mos7840_port->read_urb, GFP_ATOMIC);
2030 		if (status) {
2031 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n",
2032 			    status);
2033 			mos7840_port->read_urb_busy = false;
2034 		}
2035 	}
2036 }
2037 
2038 /*****************************************************************************
2039  * mos7840_get_lsr_info - get line status register info
2040  *
2041  * Purpose: Let user call ioctl() to get info when the UART physically
2042  * 	    is emptied.  On bus types like RS485, the transmitter must
2043  * 	    release the bus after transmitting. This must be done when
2044  * 	    the transmit shift register is empty, not be done when the
2045  * 	    transmit holding register is empty.  This functionality
2046  * 	    allows an RS485 driver to be written in user space.
2047  *****************************************************************************/
2048 
2049 static int mos7840_get_lsr_info(struct tty_struct *tty,
2050 				unsigned int __user *value)
2051 {
2052 	int count;
2053 	unsigned int result = 0;
2054 
2055 	count = mos7840_chars_in_buffer(tty);
2056 	if (count == 0)
2057 		result = TIOCSER_TEMT;
2058 
2059 	if (copy_to_user(value, &result, sizeof(int)))
2060 		return -EFAULT;
2061 	return 0;
2062 }
2063 
2064 /*****************************************************************************
2065  * mos7840_get_serial_info
2066  *      function to get information about serial port
2067  *****************************************************************************/
2068 
2069 static int mos7840_get_serial_info(struct moschip_port *mos7840_port,
2070 				   struct serial_struct __user *retinfo)
2071 {
2072 	struct serial_struct tmp;
2073 
2074 	if (mos7840_port == NULL)
2075 		return -1;
2076 
2077 	if (!retinfo)
2078 		return -EFAULT;
2079 
2080 	memset(&tmp, 0, sizeof(tmp));
2081 
2082 	tmp.type = PORT_16550A;
2083 	tmp.line = mos7840_port->port->minor;
2084 	tmp.port = mos7840_port->port->port_number;
2085 	tmp.irq = 0;
2086 	tmp.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
2087 	tmp.xmit_fifo_size = NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
2088 	tmp.baud_base = 9600;
2089 	tmp.close_delay = 5 * HZ;
2090 	tmp.closing_wait = 30 * HZ;
2091 
2092 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
2093 		return -EFAULT;
2094 	return 0;
2095 }
2096 
2097 /*****************************************************************************
2098  * SerialIoctl
2099  *	this function handles any ioctl calls to the driver
2100  *****************************************************************************/
2101 
2102 static int mos7840_ioctl(struct tty_struct *tty,
2103 			 unsigned int cmd, unsigned long arg)
2104 {
2105 	struct usb_serial_port *port = tty->driver_data;
2106 	void __user *argp = (void __user *)arg;
2107 	struct moschip_port *mos7840_port;
2108 
2109 	if (mos7840_port_paranoia_check(port, __func__))
2110 		return -1;
2111 
2112 	mos7840_port = mos7840_get_port_private(port);
2113 
2114 	if (mos7840_port == NULL)
2115 		return -1;
2116 
2117 	dev_dbg(&port->dev, "%s - cmd = 0x%x\n", __func__, cmd);
2118 
2119 	switch (cmd) {
2120 		/* return number of bytes available */
2121 
2122 	case TIOCSERGETLSR:
2123 		dev_dbg(&port->dev, "%s TIOCSERGETLSR\n", __func__);
2124 		return mos7840_get_lsr_info(tty, argp);
2125 
2126 	case TIOCGSERIAL:
2127 		dev_dbg(&port->dev, "%s TIOCGSERIAL\n", __func__);
2128 		return mos7840_get_serial_info(mos7840_port, argp);
2129 
2130 	case TIOCSSERIAL:
2131 		dev_dbg(&port->dev, "%s TIOCSSERIAL\n", __func__);
2132 		break;
2133 	default:
2134 		break;
2135 	}
2136 	return -ENOIOCTLCMD;
2137 }
2138 
2139 static int mos7810_check(struct usb_serial *serial)
2140 {
2141 	int i, pass_count = 0;
2142 	u8 *buf;
2143 	__u16 data = 0, mcr_data = 0;
2144 	__u16 test_pattern = 0x55AA;
2145 	int res;
2146 
2147 	buf = kmalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
2148 	if (!buf)
2149 		return 0;	/* failed to identify 7810 */
2150 
2151 	/* Store MCR setting */
2152 	res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
2153 		MCS_RDREQ, MCS_RD_RTYPE, 0x0300, MODEM_CONTROL_REGISTER,
2154 		buf, VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
2155 	if (res == VENDOR_READ_LENGTH)
2156 		mcr_data = *buf;
2157 
2158 	for (i = 0; i < 16; i++) {
2159 		/* Send the 1-bit test pattern out to MCS7810 test pin */
2160 		usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
2161 			MCS_WRREQ, MCS_WR_RTYPE,
2162 			(0x0300 | (((test_pattern >> i) & 0x0001) << 1)),
2163 			MODEM_CONTROL_REGISTER, NULL, 0, MOS_WDR_TIMEOUT);
2164 
2165 		/* Read the test pattern back */
2166 		res = usb_control_msg(serial->dev,
2167 				usb_rcvctrlpipe(serial->dev, 0), MCS_RDREQ,
2168 				MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
2169 				VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
2170 		if (res == VENDOR_READ_LENGTH)
2171 			data = *buf;
2172 
2173 		/* If this is a MCS7810 device, both test patterns must match */
2174 		if (((test_pattern >> i) ^ (~data >> 1)) & 0x0001)
2175 			break;
2176 
2177 		pass_count++;
2178 	}
2179 
2180 	/* Restore MCR setting */
2181 	usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), MCS_WRREQ,
2182 		MCS_WR_RTYPE, 0x0300 | mcr_data, MODEM_CONTROL_REGISTER, NULL,
2183 		0, MOS_WDR_TIMEOUT);
2184 
2185 	kfree(buf);
2186 
2187 	if (pass_count == 16)
2188 		return 1;
2189 
2190 	return 0;
2191 }
2192 
2193 static int mos7840_probe(struct usb_serial *serial,
2194 				const struct usb_device_id *id)
2195 {
2196 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
2197 	u8 *buf;
2198 	int device_type;
2199 
2200 	if (product == MOSCHIP_DEVICE_ID_7810 ||
2201 		product == MOSCHIP_DEVICE_ID_7820) {
2202 		device_type = product;
2203 		goto out;
2204 	}
2205 
2206 	buf = kzalloc(VENDOR_READ_LENGTH, GFP_KERNEL);
2207 	if (!buf)
2208 		return -ENOMEM;
2209 
2210 	usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
2211 			MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,
2212 			VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);
2213 
2214 	/* For a MCS7840 device GPIO0 must be set to 1 */
2215 	if (buf[0] & 0x01)
2216 		device_type = MOSCHIP_DEVICE_ID_7840;
2217 	else if (mos7810_check(serial))
2218 		device_type = MOSCHIP_DEVICE_ID_7810;
2219 	else
2220 		device_type = MOSCHIP_DEVICE_ID_7820;
2221 
2222 	kfree(buf);
2223 out:
2224 	usb_set_serial_data(serial, (void *)(unsigned long)device_type);
2225 
2226 	return 0;
2227 }
2228 
2229 static int mos7840_calc_num_ports(struct usb_serial *serial)
2230 {
2231 	int device_type = (unsigned long)usb_get_serial_data(serial);
2232 	int mos7840_num_ports;
2233 
2234 	mos7840_num_ports = (device_type >> 4) & 0x000F;
2235 
2236 	return mos7840_num_ports;
2237 }
2238 
2239 static int mos7840_port_probe(struct usb_serial_port *port)
2240 {
2241 	struct usb_serial *serial = port->serial;
2242 	int device_type = (unsigned long)usb_get_serial_data(serial);
2243 	struct moschip_port *mos7840_port;
2244 	int status;
2245 	int pnum;
2246 	__u16 Data;
2247 
2248 	/* we set up the pointers to the endpoints in the mos7840_open *
2249 	 * function, as the structures aren't created yet.             */
2250 
2251 	pnum = port->port_number;
2252 
2253 	dev_dbg(&port->dev, "mos7840_startup: configuring port %d\n", pnum);
2254 	mos7840_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
2255 	if (mos7840_port == NULL) {
2256 		dev_err(&port->dev, "%s - Out of memory\n", __func__);
2257 		return -ENOMEM;
2258 	}
2259 
2260 	/* Initialize all port interrupt end point to port 0 int
2261 	 * endpoint. Our device has only one interrupt end point
2262 	 * common to all port */
2263 
2264 	mos7840_port->port = port;
2265 	mos7840_set_port_private(port, mos7840_port);
2266 	spin_lock_init(&mos7840_port->pool_lock);
2267 
2268 	/* minor is not initialised until later by
2269 	 * usb-serial.c:get_free_serial() and cannot therefore be used
2270 	 * to index device instances */
2271 	mos7840_port->port_num = pnum + 1;
2272 	dev_dbg(&port->dev, "port->minor = %d\n", port->minor);
2273 	dev_dbg(&port->dev, "mos7840_port->port_num = %d\n", mos7840_port->port_num);
2274 
2275 	if (mos7840_port->port_num == 1) {
2276 		mos7840_port->SpRegOffset = 0x0;
2277 		mos7840_port->ControlRegOffset = 0x1;
2278 		mos7840_port->DcrRegOffset = 0x4;
2279 	} else if ((mos7840_port->port_num == 2) && (serial->num_ports == 4)) {
2280 		mos7840_port->SpRegOffset = 0x8;
2281 		mos7840_port->ControlRegOffset = 0x9;
2282 		mos7840_port->DcrRegOffset = 0x16;
2283 	} else if ((mos7840_port->port_num == 2) && (serial->num_ports == 2)) {
2284 		mos7840_port->SpRegOffset = 0xa;
2285 		mos7840_port->ControlRegOffset = 0xb;
2286 		mos7840_port->DcrRegOffset = 0x19;
2287 	} else if ((mos7840_port->port_num == 3) && (serial->num_ports == 4)) {
2288 		mos7840_port->SpRegOffset = 0xa;
2289 		mos7840_port->ControlRegOffset = 0xb;
2290 		mos7840_port->DcrRegOffset = 0x19;
2291 	} else if ((mos7840_port->port_num == 4) && (serial->num_ports == 4)) {
2292 		mos7840_port->SpRegOffset = 0xc;
2293 		mos7840_port->ControlRegOffset = 0xd;
2294 		mos7840_port->DcrRegOffset = 0x1c;
2295 	}
2296 	mos7840_dump_serial_port(port, mos7840_port);
2297 	mos7840_set_port_private(port, mos7840_port);
2298 
2299 	/* enable rx_disable bit in control register */
2300 	status = mos7840_get_reg_sync(port,
2301 			mos7840_port->ControlRegOffset, &Data);
2302 	if (status < 0) {
2303 		dev_dbg(&port->dev, "Reading ControlReg failed status-0x%x\n", status);
2304 		goto out;
2305 	} else
2306 		dev_dbg(&port->dev, "ControlReg Reading success val is %x, status%d\n", Data, status);
2307 	Data |= 0x08;	/* setting driver done bit */
2308 	Data |= 0x04;	/* sp1_bit to have cts change reflect in
2309 			   modem status reg */
2310 
2311 	/* Data |= 0x20; //rx_disable bit */
2312 	status = mos7840_set_reg_sync(port,
2313 			mos7840_port->ControlRegOffset, Data);
2314 	if (status < 0) {
2315 		dev_dbg(&port->dev, "Writing ControlReg failed(rx_disable) status-0x%x\n", status);
2316 		goto out;
2317 	} else
2318 		dev_dbg(&port->dev, "ControlReg Writing success(rx_disable) status%d\n", status);
2319 
2320 	/* Write default values in DCR (i.e 0x01 in DCR0, 0x05 in DCR2
2321 	   and 0x24 in DCR3 */
2322 	Data = 0x01;
2323 	status = mos7840_set_reg_sync(port,
2324 			(__u16) (mos7840_port->DcrRegOffset + 0), Data);
2325 	if (status < 0) {
2326 		dev_dbg(&port->dev, "Writing DCR0 failed status-0x%x\n", status);
2327 		goto out;
2328 	} else
2329 		dev_dbg(&port->dev, "DCR0 Writing success status%d\n", status);
2330 
2331 	Data = 0x05;
2332 	status = mos7840_set_reg_sync(port,
2333 			(__u16) (mos7840_port->DcrRegOffset + 1), Data);
2334 	if (status < 0) {
2335 		dev_dbg(&port->dev, "Writing DCR1 failed status-0x%x\n", status);
2336 		goto out;
2337 	} else
2338 		dev_dbg(&port->dev, "DCR1 Writing success status%d\n", status);
2339 
2340 	Data = 0x24;
2341 	status = mos7840_set_reg_sync(port,
2342 			(__u16) (mos7840_port->DcrRegOffset + 2), Data);
2343 	if (status < 0) {
2344 		dev_dbg(&port->dev, "Writing DCR2 failed status-0x%x\n", status);
2345 		goto out;
2346 	} else
2347 		dev_dbg(&port->dev, "DCR2 Writing success status%d\n", status);
2348 
2349 	/* write values in clkstart0x0 and clkmulti 0x20 */
2350 	Data = 0x0;
2351 	status = mos7840_set_reg_sync(port, CLK_START_VALUE_REGISTER, Data);
2352 	if (status < 0) {
2353 		dev_dbg(&port->dev, "Writing CLK_START_VALUE_REGISTER failed status-0x%x\n", status);
2354 		goto out;
2355 	} else
2356 		dev_dbg(&port->dev, "CLK_START_VALUE_REGISTER Writing success status%d\n", status);
2357 
2358 	Data = 0x20;
2359 	status = mos7840_set_reg_sync(port, CLK_MULTI_REGISTER, Data);
2360 	if (status < 0) {
2361 		dev_dbg(&port->dev, "Writing CLK_MULTI_REGISTER failed status-0x%x\n", status);
2362 		goto error;
2363 	} else
2364 		dev_dbg(&port->dev, "CLK_MULTI_REGISTER Writing success status%d\n", status);
2365 
2366 	/* write value 0x0 to scratchpad register */
2367 	Data = 0x00;
2368 	status = mos7840_set_uart_reg(port, SCRATCH_PAD_REGISTER, Data);
2369 	if (status < 0) {
2370 		dev_dbg(&port->dev, "Writing SCRATCH_PAD_REGISTER failed status-0x%x\n", status);
2371 		goto out;
2372 	} else
2373 		dev_dbg(&port->dev, "SCRATCH_PAD_REGISTER Writing success status%d\n", status);
2374 
2375 	/* Zero Length flag register */
2376 	if ((mos7840_port->port_num != 1) && (serial->num_ports == 2)) {
2377 		Data = 0xff;
2378 		status = mos7840_set_reg_sync(port,
2379 				(__u16) (ZLP_REG1 +
2380 					((__u16)mos7840_port->port_num)), Data);
2381 		dev_dbg(&port->dev, "ZLIP offset %x\n",
2382 				(__u16)(ZLP_REG1 + ((__u16) mos7840_port->port_num)));
2383 		if (status < 0) {
2384 			dev_dbg(&port->dev, "Writing ZLP_REG%d failed status-0x%x\n", pnum + 2, status);
2385 			goto out;
2386 		} else
2387 			dev_dbg(&port->dev, "ZLP_REG%d Writing success status%d\n", pnum + 2, status);
2388 	} else {
2389 		Data = 0xff;
2390 		status = mos7840_set_reg_sync(port,
2391 				(__u16) (ZLP_REG1 +
2392 					((__u16)mos7840_port->port_num) - 0x1), Data);
2393 		dev_dbg(&port->dev, "ZLIP offset %x\n",
2394 				(__u16)(ZLP_REG1 + ((__u16) mos7840_port->port_num) - 0x1));
2395 		if (status < 0) {
2396 			dev_dbg(&port->dev, "Writing ZLP_REG%d failed status-0x%x\n", pnum + 1, status);
2397 			goto out;
2398 		} else
2399 			dev_dbg(&port->dev, "ZLP_REG%d Writing success status%d\n", pnum + 1, status);
2400 
2401 	}
2402 	mos7840_port->control_urb = usb_alloc_urb(0, GFP_KERNEL);
2403 	mos7840_port->ctrl_buf = kmalloc(16, GFP_KERNEL);
2404 	mos7840_port->dr = kmalloc(sizeof(struct usb_ctrlrequest),
2405 			GFP_KERNEL);
2406 	if (!mos7840_port->control_urb || !mos7840_port->ctrl_buf ||
2407 			!mos7840_port->dr) {
2408 		status = -ENOMEM;
2409 		goto error;
2410 	}
2411 
2412 	mos7840_port->has_led = false;
2413 
2414 	/* Initialize LED timers */
2415 	if (device_type == MOSCHIP_DEVICE_ID_7810) {
2416 		mos7840_port->has_led = true;
2417 
2418 		mos7840_port->led_urb = usb_alloc_urb(0, GFP_KERNEL);
2419 		mos7840_port->led_dr = kmalloc(sizeof(*mos7840_port->led_dr),
2420 								GFP_KERNEL);
2421 		if (!mos7840_port->led_urb || !mos7840_port->led_dr) {
2422 			status = -ENOMEM;
2423 			goto error;
2424 		}
2425 
2426 		init_timer(&mos7840_port->led_timer1);
2427 		mos7840_port->led_timer1.function = mos7840_led_off;
2428 		mos7840_port->led_timer1.expires =
2429 			jiffies + msecs_to_jiffies(LED_ON_MS);
2430 		mos7840_port->led_timer1.data = (unsigned long)mos7840_port;
2431 
2432 		init_timer(&mos7840_port->led_timer2);
2433 		mos7840_port->led_timer2.function = mos7840_led_flag_off;
2434 		mos7840_port->led_timer2.expires =
2435 			jiffies + msecs_to_jiffies(LED_OFF_MS);
2436 		mos7840_port->led_timer2.data = (unsigned long)mos7840_port;
2437 
2438 		/* Turn off LED */
2439 		mos7840_set_led_sync(port, MODEM_CONTROL_REGISTER, 0x0300);
2440 	}
2441 out:
2442 	if (pnum == serial->num_ports - 1) {
2443 		/* Zero Length flag enable */
2444 		Data = 0x0f;
2445 		status = mos7840_set_reg_sync(serial->port[0], ZLP_REG5, Data);
2446 		if (status < 0) {
2447 			dev_dbg(&port->dev, "Writing ZLP_REG5 failed status-0x%x\n", status);
2448 			goto error;
2449 		} else
2450 			dev_dbg(&port->dev, "ZLP_REG5 Writing success status%d\n", status);
2451 
2452 		/* setting configuration feature to one */
2453 		usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
2454 				0x03, 0x00, 0x01, 0x00, NULL, 0x00,
2455 				MOS_WDR_TIMEOUT);
2456 	}
2457 	return 0;
2458 error:
2459 	kfree(mos7840_port->led_dr);
2460 	usb_free_urb(mos7840_port->led_urb);
2461 	kfree(mos7840_port->dr);
2462 	kfree(mos7840_port->ctrl_buf);
2463 	usb_free_urb(mos7840_port->control_urb);
2464 	kfree(mos7840_port);
2465 
2466 	return status;
2467 }
2468 
2469 static int mos7840_port_remove(struct usb_serial_port *port)
2470 {
2471 	struct moschip_port *mos7840_port;
2472 
2473 	mos7840_port = mos7840_get_port_private(port);
2474 
2475 	if (mos7840_port->has_led) {
2476 		/* Turn off LED */
2477 		mos7840_set_led_sync(port, MODEM_CONTROL_REGISTER, 0x0300);
2478 
2479 		del_timer_sync(&mos7840_port->led_timer1);
2480 		del_timer_sync(&mos7840_port->led_timer2);
2481 
2482 		usb_kill_urb(mos7840_port->led_urb);
2483 		usb_free_urb(mos7840_port->led_urb);
2484 		kfree(mos7840_port->led_dr);
2485 	}
2486 	usb_kill_urb(mos7840_port->control_urb);
2487 	usb_free_urb(mos7840_port->control_urb);
2488 	kfree(mos7840_port->ctrl_buf);
2489 	kfree(mos7840_port->dr);
2490 	kfree(mos7840_port);
2491 
2492 	return 0;
2493 }
2494 
2495 static struct usb_serial_driver moschip7840_4port_device = {
2496 	.driver = {
2497 		   .owner = THIS_MODULE,
2498 		   .name = "mos7840",
2499 		   },
2500 	.description = DRIVER_DESC,
2501 	.id_table = id_table,
2502 	.num_ports = 4,
2503 	.open = mos7840_open,
2504 	.close = mos7840_close,
2505 	.write = mos7840_write,
2506 	.write_room = mos7840_write_room,
2507 	.chars_in_buffer = mos7840_chars_in_buffer,
2508 	.throttle = mos7840_throttle,
2509 	.unthrottle = mos7840_unthrottle,
2510 	.calc_num_ports = mos7840_calc_num_ports,
2511 	.probe = mos7840_probe,
2512 	.ioctl = mos7840_ioctl,
2513 	.set_termios = mos7840_set_termios,
2514 	.break_ctl = mos7840_break,
2515 	.tiocmget = mos7840_tiocmget,
2516 	.tiocmset = mos7840_tiocmset,
2517 	.tiocmiwait = usb_serial_generic_tiocmiwait,
2518 	.get_icount = usb_serial_generic_get_icount,
2519 	.port_probe = mos7840_port_probe,
2520 	.port_remove = mos7840_port_remove,
2521 	.read_bulk_callback = mos7840_bulk_in_callback,
2522 	.read_int_callback = mos7840_interrupt_callback,
2523 };
2524 
2525 static struct usb_serial_driver * const serial_drivers[] = {
2526 	&moschip7840_4port_device, NULL
2527 };
2528 
2529 module_usb_serial_driver(serial_drivers, id_table);
2530 
2531 MODULE_DESCRIPTION(DRIVER_DESC);
2532 MODULE_LICENSE("GPL");
2533