Merge branch 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / samples / vfio-mdev / mtty.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Mediated virtual PCI serial host device driver
4  *
5  * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
6  *     Author: Neo Jia <cjia@nvidia.com>
7  *             Kirti Wankhede <kwankhede@nvidia.com>
8  *
9  * Sample driver that creates mdev device that simulates serial port over PCI
10  * card.
11  */
12
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/kernel.h>
17 #include <linux/fs.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/cdev.h>
21 #include <linux/sched.h>
22 #include <linux/wait.h>
23 #include <linux/uuid.h>
24 #include <linux/vfio.h>
25 #include <linux/iommu.h>
26 #include <linux/sysfs.h>
27 #include <linux/ctype.h>
28 #include <linux/file.h>
29 #include <linux/mdev.h>
30 #include <linux/pci.h>
31 #include <linux/serial.h>
32 #include <uapi/linux/serial_reg.h>
33 #include <linux/eventfd.h>
34 /*
35  * #defines
36  */
37
38 #define VERSION_STRING  "0.1"
39 #define DRIVER_AUTHOR   "NVIDIA Corporation"
40
41 #define MTTY_CLASS_NAME "mtty"
42
43 #define MTTY_NAME       "mtty"
44
45 #define MTTY_STRING_LEN         16
46
47 #define MTTY_CONFIG_SPACE_SIZE  0xff
48 #define MTTY_IO_BAR_SIZE        0x8
49 #define MTTY_MMIO_BAR_SIZE      0x100000
50
51 #define STORE_LE16(addr, val)   (*(u16 *)addr = val)
52 #define STORE_LE32(addr, val)   (*(u32 *)addr = val)
53
54 #define MAX_FIFO_SIZE   16
55
56 #define CIRCULAR_BUF_INC_IDX(idx)    (idx = (idx + 1) & (MAX_FIFO_SIZE - 1))
57
58 #define MTTY_VFIO_PCI_OFFSET_SHIFT   40
59
60 #define MTTY_VFIO_PCI_OFFSET_TO_INDEX(off)   (off >> MTTY_VFIO_PCI_OFFSET_SHIFT)
61 #define MTTY_VFIO_PCI_INDEX_TO_OFFSET(index) \
62                                 ((u64)(index) << MTTY_VFIO_PCI_OFFSET_SHIFT)
63 #define MTTY_VFIO_PCI_OFFSET_MASK    \
64                                 (((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1)
65 #define MAX_MTTYS       24
66
67 /*
68  * Global Structures
69  */
70
71 static struct mtty_dev {
72         dev_t           vd_devt;
73         struct class    *vd_class;
74         struct cdev     vd_cdev;
75         struct idr      vd_idr;
76         struct device   dev;
77 } mtty_dev;
78
79 struct mdev_region_info {
80         u64 start;
81         u64 phys_start;
82         u32 size;
83         u64 vfio_offset;
84 };
85
86 #if defined(DEBUG_REGS)
87 static const char *wr_reg[] = {
88         "TX",
89         "IER",
90         "FCR",
91         "LCR",
92         "MCR",
93         "LSR",
94         "MSR",
95         "SCR"
96 };
97
98 static const char *rd_reg[] = {
99         "RX",
100         "IER",
101         "IIR",
102         "LCR",
103         "MCR",
104         "LSR",
105         "MSR",
106         "SCR"
107 };
108 #endif
109
110 /* loop back buffer */
111 struct rxtx {
112         u8 fifo[MAX_FIFO_SIZE];
113         u8 head, tail;
114         u8 count;
115 };
116
117 struct serial_port {
118         u8 uart_reg[8];         /* 8 registers */
119         struct rxtx rxtx;       /* loop back buffer */
120         bool dlab;
121         bool overrun;
122         u16 divisor;
123         u8 fcr;                 /* FIFO control register */
124         u8 max_fifo_size;
125         u8 intr_trigger_level;  /* interrupt trigger level */
126 };
127
128 /* State of each mdev device */
129 struct mdev_state {
130         struct vfio_device vdev;
131         int irq_fd;
132         struct eventfd_ctx *intx_evtfd;
133         struct eventfd_ctx *msi_evtfd;
134         int irq_index;
135         u8 *vconfig;
136         struct mutex ops_lock;
137         struct mdev_device *mdev;
138         struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS];
139         u32 bar_mask[VFIO_PCI_NUM_REGIONS];
140         struct list_head next;
141         struct serial_port s[2];
142         struct mutex rxtx_lock;
143         struct vfio_device_info dev_info;
144         int nr_ports;
145 };
146
147 static atomic_t mdev_avail_ports = ATOMIC_INIT(MAX_MTTYS);
148
149 static const struct file_operations vd_fops = {
150         .owner          = THIS_MODULE,
151 };
152
153 static const struct vfio_device_ops mtty_dev_ops;
154
155 /* function prototypes */
156
157 static int mtty_trigger_interrupt(struct mdev_state *mdev_state);
158
159 /* Helper functions */
160
161 static void dump_buffer(u8 *buf, uint32_t count)
162 {
163 #if defined(DEBUG)
164         int i;
165
166         pr_info("Buffer:\n");
167         for (i = 0; i < count; i++) {
168                 pr_info("%2x ", *(buf + i));
169                 if ((i + 1) % 16 == 0)
170                         pr_info("\n");
171         }
172 #endif
173 }
174
175 static void mtty_create_config_space(struct mdev_state *mdev_state)
176 {
177         /* PCI dev ID */
178         STORE_LE32((u32 *) &mdev_state->vconfig[0x0], 0x32534348);
179
180         /* Control: I/O+, Mem-, BusMaster- */
181         STORE_LE16((u16 *) &mdev_state->vconfig[0x4], 0x0001);
182
183         /* Status: capabilities list absent */
184         STORE_LE16((u16 *) &mdev_state->vconfig[0x6], 0x0200);
185
186         /* Rev ID */
187         mdev_state->vconfig[0x8] =  0x10;
188
189         /* programming interface class : 16550-compatible serial controller */
190         mdev_state->vconfig[0x9] =  0x02;
191
192         /* Sub class : 00 */
193         mdev_state->vconfig[0xa] =  0x00;
194
195         /* Base class : Simple Communication controllers */
196         mdev_state->vconfig[0xb] =  0x07;
197
198         /* base address registers */
199         /* BAR0: IO space */
200         STORE_LE32((u32 *) &mdev_state->vconfig[0x10], 0x000001);
201         mdev_state->bar_mask[0] = ~(MTTY_IO_BAR_SIZE) + 1;
202
203         if (mdev_state->nr_ports == 2) {
204                 /* BAR1: IO space */
205                 STORE_LE32((u32 *) &mdev_state->vconfig[0x14], 0x000001);
206                 mdev_state->bar_mask[1] = ~(MTTY_IO_BAR_SIZE) + 1;
207         }
208
209         /* Subsystem ID */
210         STORE_LE32((u32 *) &mdev_state->vconfig[0x2c], 0x32534348);
211
212         mdev_state->vconfig[0x34] =  0x00;   /* Cap Ptr */
213         mdev_state->vconfig[0x3d] =  0x01;   /* interrupt pin (INTA#) */
214
215         /* Vendor specific data */
216         mdev_state->vconfig[0x40] =  0x23;
217         mdev_state->vconfig[0x43] =  0x80;
218         mdev_state->vconfig[0x44] =  0x23;
219         mdev_state->vconfig[0x48] =  0x23;
220         mdev_state->vconfig[0x4c] =  0x23;
221
222         mdev_state->vconfig[0x60] =  0x50;
223         mdev_state->vconfig[0x61] =  0x43;
224         mdev_state->vconfig[0x62] =  0x49;
225         mdev_state->vconfig[0x63] =  0x20;
226         mdev_state->vconfig[0x64] =  0x53;
227         mdev_state->vconfig[0x65] =  0x65;
228         mdev_state->vconfig[0x66] =  0x72;
229         mdev_state->vconfig[0x67] =  0x69;
230         mdev_state->vconfig[0x68] =  0x61;
231         mdev_state->vconfig[0x69] =  0x6c;
232         mdev_state->vconfig[0x6a] =  0x2f;
233         mdev_state->vconfig[0x6b] =  0x55;
234         mdev_state->vconfig[0x6c] =  0x41;
235         mdev_state->vconfig[0x6d] =  0x52;
236         mdev_state->vconfig[0x6e] =  0x54;
237 }
238
239 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
240                                  u8 *buf, u32 count)
241 {
242         u32 cfg_addr, bar_mask, bar_index = 0;
243
244         switch (offset) {
245         case 0x04: /* device control */
246         case 0x06: /* device status */
247                 /* do nothing */
248                 break;
249         case 0x3c:  /* interrupt line */
250                 mdev_state->vconfig[0x3c] = buf[0];
251                 break;
252         case 0x3d:
253                 /*
254                  * Interrupt Pin is hardwired to INTA.
255                  * This field is write protected by hardware
256                  */
257                 break;
258         case 0x10:  /* BAR0 */
259         case 0x14:  /* BAR1 */
260                 if (offset == 0x10)
261                         bar_index = 0;
262                 else if (offset == 0x14)
263                         bar_index = 1;
264
265                 if ((mdev_state->nr_ports == 1) && (bar_index == 1)) {
266                         STORE_LE32(&mdev_state->vconfig[offset], 0);
267                         break;
268                 }
269
270                 cfg_addr = *(u32 *)buf;
271                 pr_info("BAR%d addr 0x%x\n", bar_index, cfg_addr);
272
273                 if (cfg_addr == 0xffffffff) {
274                         bar_mask = mdev_state->bar_mask[bar_index];
275                         cfg_addr = (cfg_addr & bar_mask);
276                 }
277
278                 cfg_addr |= (mdev_state->vconfig[offset] & 0x3ul);
279                 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
280                 break;
281         case 0x18:  /* BAR2 */
282         case 0x1c:  /* BAR3 */
283         case 0x20:  /* BAR4 */
284                 STORE_LE32(&mdev_state->vconfig[offset], 0);
285                 break;
286         default:
287                 pr_info("PCI config write @0x%x of %d bytes not handled\n",
288                         offset, count);
289                 break;
290         }
291 }
292
293 static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
294                                 u16 offset, u8 *buf, u32 count)
295 {
296         u8 data = *buf;
297
298         /* Handle data written by guest */
299         switch (offset) {
300         case UART_TX:
301                 /* if DLAB set, data is LSB of divisor */
302                 if (mdev_state->s[index].dlab) {
303                         mdev_state->s[index].divisor |= data;
304                         break;
305                 }
306
307                 mutex_lock(&mdev_state->rxtx_lock);
308
309                 /* save in TX buffer */
310                 if (mdev_state->s[index].rxtx.count <
311                                 mdev_state->s[index].max_fifo_size) {
312                         mdev_state->s[index].rxtx.fifo[
313                                         mdev_state->s[index].rxtx.head] = data;
314                         mdev_state->s[index].rxtx.count++;
315                         CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.head);
316                         mdev_state->s[index].overrun = false;
317
318                         /*
319                          * Trigger interrupt if receive data interrupt is
320                          * enabled and fifo reached trigger level
321                          */
322                         if ((mdev_state->s[index].uart_reg[UART_IER] &
323                                                 UART_IER_RDI) &&
324                            (mdev_state->s[index].rxtx.count ==
325                                     mdev_state->s[index].intr_trigger_level)) {
326                                 /* trigger interrupt */
327 #if defined(DEBUG_INTR)
328                                 pr_err("Serial port %d: Fifo level trigger\n",
329                                         index);
330 #endif
331                                 mtty_trigger_interrupt(mdev_state);
332                         }
333                 } else {
334 #if defined(DEBUG_INTR)
335                         pr_err("Serial port %d: Buffer Overflow\n", index);
336 #endif
337                         mdev_state->s[index].overrun = true;
338
339                         /*
340                          * Trigger interrupt if receiver line status interrupt
341                          * is enabled
342                          */
343                         if (mdev_state->s[index].uart_reg[UART_IER] &
344                                                                 UART_IER_RLSI)
345                                 mtty_trigger_interrupt(mdev_state);
346                 }
347                 mutex_unlock(&mdev_state->rxtx_lock);
348                 break;
349
350         case UART_IER:
351                 /* if DLAB set, data is MSB of divisor */
352                 if (mdev_state->s[index].dlab)
353                         mdev_state->s[index].divisor |= (u16)data << 8;
354                 else {
355                         mdev_state->s[index].uart_reg[offset] = data;
356                         mutex_lock(&mdev_state->rxtx_lock);
357                         if ((data & UART_IER_THRI) &&
358                             (mdev_state->s[index].rxtx.head ==
359                                         mdev_state->s[index].rxtx.tail)) {
360 #if defined(DEBUG_INTR)
361                                 pr_err("Serial port %d: IER_THRI write\n",
362                                         index);
363 #endif
364                                 mtty_trigger_interrupt(mdev_state);
365                         }
366
367                         mutex_unlock(&mdev_state->rxtx_lock);
368                 }
369
370                 break;
371
372         case UART_FCR:
373                 mdev_state->s[index].fcr = data;
374
375                 mutex_lock(&mdev_state->rxtx_lock);
376                 if (data & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)) {
377                         /* clear loop back FIFO */
378                         mdev_state->s[index].rxtx.count = 0;
379                         mdev_state->s[index].rxtx.head = 0;
380                         mdev_state->s[index].rxtx.tail = 0;
381                 }
382                 mutex_unlock(&mdev_state->rxtx_lock);
383
384                 switch (data & UART_FCR_TRIGGER_MASK) {
385                 case UART_FCR_TRIGGER_1:
386                         mdev_state->s[index].intr_trigger_level = 1;
387                         break;
388
389                 case UART_FCR_TRIGGER_4:
390                         mdev_state->s[index].intr_trigger_level = 4;
391                         break;
392
393                 case UART_FCR_TRIGGER_8:
394                         mdev_state->s[index].intr_trigger_level = 8;
395                         break;
396
397                 case UART_FCR_TRIGGER_14:
398                         mdev_state->s[index].intr_trigger_level = 14;
399                         break;
400                 }
401
402                 /*
403                  * Set trigger level to 1 otherwise or  implement timer with
404                  * timeout of 4 characters and on expiring that timer set
405                  * Recevice data timeout in IIR register
406                  */
407                 mdev_state->s[index].intr_trigger_level = 1;
408                 if (data & UART_FCR_ENABLE_FIFO)
409                         mdev_state->s[index].max_fifo_size = MAX_FIFO_SIZE;
410                 else {
411                         mdev_state->s[index].max_fifo_size = 1;
412                         mdev_state->s[index].intr_trigger_level = 1;
413                 }
414
415                 break;
416
417         case UART_LCR:
418                 if (data & UART_LCR_DLAB) {
419                         mdev_state->s[index].dlab = true;
420                         mdev_state->s[index].divisor = 0;
421                 } else
422                         mdev_state->s[index].dlab = false;
423
424                 mdev_state->s[index].uart_reg[offset] = data;
425                 break;
426
427         case UART_MCR:
428                 mdev_state->s[index].uart_reg[offset] = data;
429
430                 if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
431                                 (data & UART_MCR_OUT2)) {
432 #if defined(DEBUG_INTR)
433                         pr_err("Serial port %d: MCR_OUT2 write\n", index);
434 #endif
435                         mtty_trigger_interrupt(mdev_state);
436                 }
437
438                 if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
439                                 (data & (UART_MCR_RTS | UART_MCR_DTR))) {
440 #if defined(DEBUG_INTR)
441                         pr_err("Serial port %d: MCR RTS/DTR write\n", index);
442 #endif
443                         mtty_trigger_interrupt(mdev_state);
444                 }
445                 break;
446
447         case UART_LSR:
448         case UART_MSR:
449                 /* do nothing */
450                 break;
451
452         case UART_SCR:
453                 mdev_state->s[index].uart_reg[offset] = data;
454                 break;
455
456         default:
457                 break;
458         }
459 }
460
461 static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
462                             u16 offset, u8 *buf, u32 count)
463 {
464         /* Handle read requests by guest */
465         switch (offset) {
466         case UART_RX:
467                 /* if DLAB set, data is LSB of divisor */
468                 if (mdev_state->s[index].dlab) {
469                         *buf  = (u8)mdev_state->s[index].divisor;
470                         break;
471                 }
472
473                 mutex_lock(&mdev_state->rxtx_lock);
474                 /* return data in tx buffer */
475                 if (mdev_state->s[index].rxtx.head !=
476                                  mdev_state->s[index].rxtx.tail) {
477                         *buf = mdev_state->s[index].rxtx.fifo[
478                                                 mdev_state->s[index].rxtx.tail];
479                         mdev_state->s[index].rxtx.count--;
480                         CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.tail);
481                 }
482
483                 if (mdev_state->s[index].rxtx.head ==
484                                 mdev_state->s[index].rxtx.tail) {
485                 /*
486                  *  Trigger interrupt if tx buffer empty interrupt is
487                  *  enabled and fifo is empty
488                  */
489 #if defined(DEBUG_INTR)
490                         pr_err("Serial port %d: Buffer Empty\n", index);
491 #endif
492                         if (mdev_state->s[index].uart_reg[UART_IER] &
493                                                          UART_IER_THRI)
494                                 mtty_trigger_interrupt(mdev_state);
495                 }
496                 mutex_unlock(&mdev_state->rxtx_lock);
497
498                 break;
499
500         case UART_IER:
501                 if (mdev_state->s[index].dlab) {
502                         *buf = (u8)(mdev_state->s[index].divisor >> 8);
503                         break;
504                 }
505                 *buf = mdev_state->s[index].uart_reg[offset] & 0x0f;
506                 break;
507
508         case UART_IIR:
509         {
510                 u8 ier = mdev_state->s[index].uart_reg[UART_IER];
511                 *buf = 0;
512
513                 mutex_lock(&mdev_state->rxtx_lock);
514                 /* Interrupt priority 1: Parity, overrun, framing or break */
515                 if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun)
516                         *buf |= UART_IIR_RLSI;
517
518                 /* Interrupt priority 2: Fifo trigger level reached */
519                 if ((ier & UART_IER_RDI) &&
520                     (mdev_state->s[index].rxtx.count >=
521                       mdev_state->s[index].intr_trigger_level))
522                         *buf |= UART_IIR_RDI;
523
524                 /* Interrupt priotiry 3: transmitter holding register empty */
525                 if ((ier & UART_IER_THRI) &&
526                     (mdev_state->s[index].rxtx.head ==
527                                 mdev_state->s[index].rxtx.tail))
528                         *buf |= UART_IIR_THRI;
529
530                 /* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD  */
531                 if ((ier & UART_IER_MSI) &&
532                     (mdev_state->s[index].uart_reg[UART_MCR] &
533                                  (UART_MCR_RTS | UART_MCR_DTR)))
534                         *buf |= UART_IIR_MSI;
535
536                 /* bit0: 0=> interrupt pending, 1=> no interrupt is pending */
537                 if (*buf == 0)
538                         *buf = UART_IIR_NO_INT;
539
540                 /* set bit 6 & 7 to be 16550 compatible */
541                 *buf |= 0xC0;
542                 mutex_unlock(&mdev_state->rxtx_lock);
543         }
544         break;
545
546         case UART_LCR:
547         case UART_MCR:
548                 *buf = mdev_state->s[index].uart_reg[offset];
549                 break;
550
551         case UART_LSR:
552         {
553                 u8 lsr = 0;
554
555                 mutex_lock(&mdev_state->rxtx_lock);
556                 /* atleast one char in FIFO */
557                 if (mdev_state->s[index].rxtx.head !=
558                                  mdev_state->s[index].rxtx.tail)
559                         lsr |= UART_LSR_DR;
560
561                 /* if FIFO overrun */
562                 if (mdev_state->s[index].overrun)
563                         lsr |= UART_LSR_OE;
564
565                 /* transmit FIFO empty and tramsitter empty */
566                 if (mdev_state->s[index].rxtx.head ==
567                                  mdev_state->s[index].rxtx.tail)
568                         lsr |= UART_LSR_TEMT | UART_LSR_THRE;
569
570                 mutex_unlock(&mdev_state->rxtx_lock);
571                 *buf = lsr;
572                 break;
573         }
574         case UART_MSR:
575                 *buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD;
576
577                 mutex_lock(&mdev_state->rxtx_lock);
578                 /* if AFE is 1 and FIFO have space, set CTS bit */
579                 if (mdev_state->s[index].uart_reg[UART_MCR] &
580                                                  UART_MCR_AFE) {
581                         if (mdev_state->s[index].rxtx.count <
582                                         mdev_state->s[index].max_fifo_size)
583                                 *buf |= UART_MSR_CTS | UART_MSR_DCTS;
584                 } else
585                         *buf |= UART_MSR_CTS | UART_MSR_DCTS;
586                 mutex_unlock(&mdev_state->rxtx_lock);
587
588                 break;
589
590         case UART_SCR:
591                 *buf = mdev_state->s[index].uart_reg[offset];
592                 break;
593
594         default:
595                 break;
596         }
597 }
598
599 static void mdev_read_base(struct mdev_state *mdev_state)
600 {
601         int index, pos;
602         u32 start_lo, start_hi;
603         u32 mem_type;
604
605         pos = PCI_BASE_ADDRESS_0;
606
607         for (index = 0; index <= VFIO_PCI_BAR5_REGION_INDEX; index++) {
608
609                 if (!mdev_state->region_info[index].size)
610                         continue;
611
612                 start_lo = (*(u32 *)(mdev_state->vconfig + pos)) &
613                         PCI_BASE_ADDRESS_MEM_MASK;
614                 mem_type = (*(u32 *)(mdev_state->vconfig + pos)) &
615                         PCI_BASE_ADDRESS_MEM_TYPE_MASK;
616
617                 switch (mem_type) {
618                 case PCI_BASE_ADDRESS_MEM_TYPE_64:
619                         start_hi = (*(u32 *)(mdev_state->vconfig + pos + 4));
620                         pos += 4;
621                         break;
622                 case PCI_BASE_ADDRESS_MEM_TYPE_32:
623                 case PCI_BASE_ADDRESS_MEM_TYPE_1M:
624                         /* 1M mem BAR treated as 32-bit BAR */
625                 default:
626                         /* mem unknown type treated as 32-bit BAR */
627                         start_hi = 0;
628                         break;
629                 }
630                 pos += 4;
631                 mdev_state->region_info[index].start = ((u64)start_hi << 32) |
632                                                         start_lo;
633         }
634 }
635
636 static ssize_t mdev_access(struct mdev_state *mdev_state, u8 *buf, size_t count,
637                            loff_t pos, bool is_write)
638 {
639         unsigned int index;
640         loff_t offset;
641         int ret = 0;
642
643         if (!buf)
644                 return -EINVAL;
645
646         mutex_lock(&mdev_state->ops_lock);
647
648         index = MTTY_VFIO_PCI_OFFSET_TO_INDEX(pos);
649         offset = pos & MTTY_VFIO_PCI_OFFSET_MASK;
650         switch (index) {
651         case VFIO_PCI_CONFIG_REGION_INDEX:
652
653 #if defined(DEBUG)
654                 pr_info("%s: PCI config space %s at offset 0x%llx\n",
655                          __func__, is_write ? "write" : "read", offset);
656 #endif
657                 if (is_write) {
658                         dump_buffer(buf, count);
659                         handle_pci_cfg_write(mdev_state, offset, buf, count);
660                 } else {
661                         memcpy(buf, (mdev_state->vconfig + offset), count);
662                         dump_buffer(buf, count);
663                 }
664
665                 break;
666
667         case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
668                 if (!mdev_state->region_info[index].start)
669                         mdev_read_base(mdev_state);
670
671                 if (is_write) {
672                         dump_buffer(buf, count);
673
674 #if defined(DEBUG_REGS)
675                         pr_info("%s: BAR%d  WR @0x%llx %s val:0x%02x dlab:%d\n",
676                                 __func__, index, offset, wr_reg[offset],
677                                 *buf, mdev_state->s[index].dlab);
678 #endif
679                         handle_bar_write(index, mdev_state, offset, buf, count);
680                 } else {
681                         handle_bar_read(index, mdev_state, offset, buf, count);
682                         dump_buffer(buf, count);
683
684 #if defined(DEBUG_REGS)
685                         pr_info("%s: BAR%d  RD @0x%llx %s val:0x%02x dlab:%d\n",
686                                 __func__, index, offset, rd_reg[offset],
687                                 *buf, mdev_state->s[index].dlab);
688 #endif
689                 }
690                 break;
691
692         default:
693                 ret = -1;
694                 goto accessfailed;
695         }
696
697         ret = count;
698
699
700 accessfailed:
701         mutex_unlock(&mdev_state->ops_lock);
702
703         return ret;
704 }
705
706 static int mtty_probe(struct mdev_device *mdev)
707 {
708         struct mdev_state *mdev_state;
709         int nr_ports = mdev_get_type_group_id(mdev) + 1;
710         int avail_ports = atomic_read(&mdev_avail_ports);
711         int ret;
712
713         do {
714                 if (avail_ports < nr_ports)
715                         return -ENOSPC;
716         } while (!atomic_try_cmpxchg(&mdev_avail_ports,
717                                      &avail_ports, avail_ports - nr_ports));
718
719         mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
720         if (mdev_state == NULL) {
721                 ret = -ENOMEM;
722                 goto err_nr_ports;
723         }
724
725         vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mtty_dev_ops);
726
727         mdev_state->nr_ports = nr_ports;
728         mdev_state->irq_index = -1;
729         mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
730         mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE;
731         mutex_init(&mdev_state->rxtx_lock);
732         mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL);
733
734         if (mdev_state->vconfig == NULL) {
735                 ret = -ENOMEM;
736                 goto err_state;
737         }
738
739         mutex_init(&mdev_state->ops_lock);
740         mdev_state->mdev = mdev;
741
742         mtty_create_config_space(mdev_state);
743
744         ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
745         if (ret)
746                 goto err_vconfig;
747         dev_set_drvdata(&mdev->dev, mdev_state);
748         return 0;
749
750 err_vconfig:
751         kfree(mdev_state->vconfig);
752 err_state:
753         vfio_uninit_group_dev(&mdev_state->vdev);
754         kfree(mdev_state);
755 err_nr_ports:
756         atomic_add(nr_ports, &mdev_avail_ports);
757         return ret;
758 }
759
760 static void mtty_remove(struct mdev_device *mdev)
761 {
762         struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
763         int nr_ports = mdev_state->nr_ports;
764
765         vfio_unregister_group_dev(&mdev_state->vdev);
766
767         kfree(mdev_state->vconfig);
768         vfio_uninit_group_dev(&mdev_state->vdev);
769         kfree(mdev_state);
770         atomic_add(nr_ports, &mdev_avail_ports);
771 }
772
773 static int mtty_reset(struct mdev_state *mdev_state)
774 {
775         pr_info("%s: called\n", __func__);
776
777         return 0;
778 }
779
780 static ssize_t mtty_read(struct vfio_device *vdev, char __user *buf,
781                          size_t count, loff_t *ppos)
782 {
783         struct mdev_state *mdev_state =
784                 container_of(vdev, struct mdev_state, vdev);
785         unsigned int done = 0;
786         int ret;
787
788         while (count) {
789                 size_t filled;
790
791                 if (count >= 4 && !(*ppos % 4)) {
792                         u32 val;
793
794                         ret =  mdev_access(mdev_state, (u8 *)&val, sizeof(val),
795                                            *ppos, false);
796                         if (ret <= 0)
797                                 goto read_err;
798
799                         if (copy_to_user(buf, &val, sizeof(val)))
800                                 goto read_err;
801
802                         filled = 4;
803                 } else if (count >= 2 && !(*ppos % 2)) {
804                         u16 val;
805
806                         ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
807                                           *ppos, false);
808                         if (ret <= 0)
809                                 goto read_err;
810
811                         if (copy_to_user(buf, &val, sizeof(val)))
812                                 goto read_err;
813
814                         filled = 2;
815                 } else {
816                         u8 val;
817
818                         ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
819                                           *ppos, false);
820                         if (ret <= 0)
821                                 goto read_err;
822
823                         if (copy_to_user(buf, &val, sizeof(val)))
824                                 goto read_err;
825
826                         filled = 1;
827                 }
828
829                 count -= filled;
830                 done += filled;
831                 *ppos += filled;
832                 buf += filled;
833         }
834
835         return done;
836
837 read_err:
838         return -EFAULT;
839 }
840
841 static ssize_t mtty_write(struct vfio_device *vdev, const char __user *buf,
842                    size_t count, loff_t *ppos)
843 {
844         struct mdev_state *mdev_state =
845                 container_of(vdev, struct mdev_state, vdev);
846         unsigned int done = 0;
847         int ret;
848
849         while (count) {
850                 size_t filled;
851
852                 if (count >= 4 && !(*ppos % 4)) {
853                         u32 val;
854
855                         if (copy_from_user(&val, buf, sizeof(val)))
856                                 goto write_err;
857
858                         ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
859                                           *ppos, true);
860                         if (ret <= 0)
861                                 goto write_err;
862
863                         filled = 4;
864                 } else if (count >= 2 && !(*ppos % 2)) {
865                         u16 val;
866
867                         if (copy_from_user(&val, buf, sizeof(val)))
868                                 goto write_err;
869
870                         ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
871                                           *ppos, true);
872                         if (ret <= 0)
873                                 goto write_err;
874
875                         filled = 2;
876                 } else {
877                         u8 val;
878
879                         if (copy_from_user(&val, buf, sizeof(val)))
880                                 goto write_err;
881
882                         ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
883                                           *ppos, true);
884                         if (ret <= 0)
885                                 goto write_err;
886
887                         filled = 1;
888                 }
889                 count -= filled;
890                 done += filled;
891                 *ppos += filled;
892                 buf += filled;
893         }
894
895         return done;
896 write_err:
897         return -EFAULT;
898 }
899
900 static int mtty_set_irqs(struct mdev_state *mdev_state, uint32_t flags,
901                          unsigned int index, unsigned int start,
902                          unsigned int count, void *data)
903 {
904         int ret = 0;
905
906         mutex_lock(&mdev_state->ops_lock);
907         switch (index) {
908         case VFIO_PCI_INTX_IRQ_INDEX:
909                 switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
910                 case VFIO_IRQ_SET_ACTION_MASK:
911                 case VFIO_IRQ_SET_ACTION_UNMASK:
912                         break;
913                 case VFIO_IRQ_SET_ACTION_TRIGGER:
914                 {
915                         if (flags & VFIO_IRQ_SET_DATA_NONE) {
916                                 pr_info("%s: disable INTx\n", __func__);
917                                 if (mdev_state->intx_evtfd)
918                                         eventfd_ctx_put(mdev_state->intx_evtfd);
919                                 break;
920                         }
921
922                         if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
923                                 int fd = *(int *)data;
924
925                                 if (fd > 0) {
926                                         struct eventfd_ctx *evt;
927
928                                         evt = eventfd_ctx_fdget(fd);
929                                         if (IS_ERR(evt)) {
930                                                 ret = PTR_ERR(evt);
931                                                 break;
932                                         }
933                                         mdev_state->intx_evtfd = evt;
934                                         mdev_state->irq_fd = fd;
935                                         mdev_state->irq_index = index;
936                                         break;
937                                 }
938                         }
939                         break;
940                 }
941                 }
942                 break;
943         case VFIO_PCI_MSI_IRQ_INDEX:
944                 switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
945                 case VFIO_IRQ_SET_ACTION_MASK:
946                 case VFIO_IRQ_SET_ACTION_UNMASK:
947                         break;
948                 case VFIO_IRQ_SET_ACTION_TRIGGER:
949                         if (flags & VFIO_IRQ_SET_DATA_NONE) {
950                                 if (mdev_state->msi_evtfd)
951                                         eventfd_ctx_put(mdev_state->msi_evtfd);
952                                 pr_info("%s: disable MSI\n", __func__);
953                                 mdev_state->irq_index = VFIO_PCI_INTX_IRQ_INDEX;
954                                 break;
955                         }
956                         if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
957                                 int fd = *(int *)data;
958                                 struct eventfd_ctx *evt;
959
960                                 if (fd <= 0)
961                                         break;
962
963                                 if (mdev_state->msi_evtfd)
964                                         break;
965
966                                 evt = eventfd_ctx_fdget(fd);
967                                 if (IS_ERR(evt)) {
968                                         ret = PTR_ERR(evt);
969                                         break;
970                                 }
971                                 mdev_state->msi_evtfd = evt;
972                                 mdev_state->irq_fd = fd;
973                                 mdev_state->irq_index = index;
974                         }
975                         break;
976         }
977         break;
978         case VFIO_PCI_MSIX_IRQ_INDEX:
979                 pr_info("%s: MSIX_IRQ\n", __func__);
980                 break;
981         case VFIO_PCI_ERR_IRQ_INDEX:
982                 pr_info("%s: ERR_IRQ\n", __func__);
983                 break;
984         case VFIO_PCI_REQ_IRQ_INDEX:
985                 pr_info("%s: REQ_IRQ\n", __func__);
986                 break;
987         }
988
989         mutex_unlock(&mdev_state->ops_lock);
990         return ret;
991 }
992
993 static int mtty_trigger_interrupt(struct mdev_state *mdev_state)
994 {
995         int ret = -1;
996
997         if ((mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX) &&
998             (!mdev_state->msi_evtfd))
999                 return -EINVAL;
1000         else if ((mdev_state->irq_index == VFIO_PCI_INTX_IRQ_INDEX) &&
1001                  (!mdev_state->intx_evtfd)) {
1002                 pr_info("%s: Intr eventfd not found\n", __func__);
1003                 return -EINVAL;
1004         }
1005
1006         if (mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX)
1007                 ret = eventfd_signal(mdev_state->msi_evtfd, 1);
1008         else
1009                 ret = eventfd_signal(mdev_state->intx_evtfd, 1);
1010
1011 #if defined(DEBUG_INTR)
1012         pr_info("Intx triggered\n");
1013 #endif
1014         if (ret != 1)
1015                 pr_err("%s: eventfd signal failed (%d)\n", __func__, ret);
1016
1017         return ret;
1018 }
1019
1020 static int mtty_get_region_info(struct mdev_state *mdev_state,
1021                          struct vfio_region_info *region_info,
1022                          u16 *cap_type_id, void **cap_type)
1023 {
1024         unsigned int size = 0;
1025         u32 bar_index;
1026
1027         bar_index = region_info->index;
1028         if (bar_index >= VFIO_PCI_NUM_REGIONS)
1029                 return -EINVAL;
1030
1031         mutex_lock(&mdev_state->ops_lock);
1032
1033         switch (bar_index) {
1034         case VFIO_PCI_CONFIG_REGION_INDEX:
1035                 size = MTTY_CONFIG_SPACE_SIZE;
1036                 break;
1037         case VFIO_PCI_BAR0_REGION_INDEX:
1038                 size = MTTY_IO_BAR_SIZE;
1039                 break;
1040         case VFIO_PCI_BAR1_REGION_INDEX:
1041                 if (mdev_state->nr_ports == 2)
1042                         size = MTTY_IO_BAR_SIZE;
1043                 break;
1044         default:
1045                 size = 0;
1046                 break;
1047         }
1048
1049         mdev_state->region_info[bar_index].size = size;
1050         mdev_state->region_info[bar_index].vfio_offset =
1051                 MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1052
1053         region_info->size = size;
1054         region_info->offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
1055         region_info->flags = VFIO_REGION_INFO_FLAG_READ |
1056                 VFIO_REGION_INFO_FLAG_WRITE;
1057         mutex_unlock(&mdev_state->ops_lock);
1058         return 0;
1059 }
1060
1061 static int mtty_get_irq_info(struct vfio_irq_info *irq_info)
1062 {
1063         switch (irq_info->index) {
1064         case VFIO_PCI_INTX_IRQ_INDEX:
1065         case VFIO_PCI_MSI_IRQ_INDEX:
1066         case VFIO_PCI_REQ_IRQ_INDEX:
1067                 break;
1068
1069         default:
1070                 return -EINVAL;
1071         }
1072
1073         irq_info->flags = VFIO_IRQ_INFO_EVENTFD;
1074         irq_info->count = 1;
1075
1076         if (irq_info->index == VFIO_PCI_INTX_IRQ_INDEX)
1077                 irq_info->flags |= (VFIO_IRQ_INFO_MASKABLE |
1078                                 VFIO_IRQ_INFO_AUTOMASKED);
1079         else
1080                 irq_info->flags |= VFIO_IRQ_INFO_NORESIZE;
1081
1082         return 0;
1083 }
1084
1085 static int mtty_get_device_info(struct vfio_device_info *dev_info)
1086 {
1087         dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
1088         dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
1089         dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
1090
1091         return 0;
1092 }
1093
1094 static long mtty_ioctl(struct vfio_device *vdev, unsigned int cmd,
1095                         unsigned long arg)
1096 {
1097         struct mdev_state *mdev_state =
1098                 container_of(vdev, struct mdev_state, vdev);
1099         int ret = 0;
1100         unsigned long minsz;
1101
1102         switch (cmd) {
1103         case VFIO_DEVICE_GET_INFO:
1104         {
1105                 struct vfio_device_info info;
1106
1107                 minsz = offsetofend(struct vfio_device_info, num_irqs);
1108
1109                 if (copy_from_user(&info, (void __user *)arg, minsz))
1110                         return -EFAULT;
1111
1112                 if (info.argsz < minsz)
1113                         return -EINVAL;
1114
1115                 ret = mtty_get_device_info(&info);
1116                 if (ret)
1117                         return ret;
1118
1119                 memcpy(&mdev_state->dev_info, &info, sizeof(info));
1120
1121                 if (copy_to_user((void __user *)arg, &info, minsz))
1122                         return -EFAULT;
1123
1124                 return 0;
1125         }
1126         case VFIO_DEVICE_GET_REGION_INFO:
1127         {
1128                 struct vfio_region_info info;
1129                 u16 cap_type_id = 0;
1130                 void *cap_type = NULL;
1131
1132                 minsz = offsetofend(struct vfio_region_info, offset);
1133
1134                 if (copy_from_user(&info, (void __user *)arg, minsz))
1135                         return -EFAULT;
1136
1137                 if (info.argsz < minsz)
1138                         return -EINVAL;
1139
1140                 ret = mtty_get_region_info(mdev_state, &info, &cap_type_id,
1141                                            &cap_type);
1142                 if (ret)
1143                         return ret;
1144
1145                 if (copy_to_user((void __user *)arg, &info, minsz))
1146                         return -EFAULT;
1147
1148                 return 0;
1149         }
1150
1151         case VFIO_DEVICE_GET_IRQ_INFO:
1152         {
1153                 struct vfio_irq_info info;
1154
1155                 minsz = offsetofend(struct vfio_irq_info, count);
1156
1157                 if (copy_from_user(&info, (void __user *)arg, minsz))
1158                         return -EFAULT;
1159
1160                 if ((info.argsz < minsz) ||
1161                     (info.index >= mdev_state->dev_info.num_irqs))
1162                         return -EINVAL;
1163
1164                 ret = mtty_get_irq_info(&info);
1165                 if (ret)
1166                         return ret;
1167
1168                 if (copy_to_user((void __user *)arg, &info, minsz))
1169                         return -EFAULT;
1170
1171                 return 0;
1172         }
1173         case VFIO_DEVICE_SET_IRQS:
1174         {
1175                 struct vfio_irq_set hdr;
1176                 u8 *data = NULL, *ptr = NULL;
1177                 size_t data_size = 0;
1178
1179                 minsz = offsetofend(struct vfio_irq_set, count);
1180
1181                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
1182                         return -EFAULT;
1183
1184                 ret = vfio_set_irqs_validate_and_prepare(&hdr,
1185                                                 mdev_state->dev_info.num_irqs,
1186                                                 VFIO_PCI_NUM_IRQS,
1187                                                 &data_size);
1188                 if (ret)
1189                         return ret;
1190
1191                 if (data_size) {
1192                         ptr = data = memdup_user((void __user *)(arg + minsz),
1193                                                  data_size);
1194                         if (IS_ERR(data))
1195                                 return PTR_ERR(data);
1196                 }
1197
1198                 ret = mtty_set_irqs(mdev_state, hdr.flags, hdr.index, hdr.start,
1199                                     hdr.count, data);
1200
1201                 kfree(ptr);
1202                 return ret;
1203         }
1204         case VFIO_DEVICE_RESET:
1205                 return mtty_reset(mdev_state);
1206         }
1207         return -ENOTTY;
1208 }
1209
1210 static ssize_t
1211 sample_mtty_dev_show(struct device *dev, struct device_attribute *attr,
1212                      char *buf)
1213 {
1214         return sprintf(buf, "This is phy device\n");
1215 }
1216
1217 static DEVICE_ATTR_RO(sample_mtty_dev);
1218
1219 static struct attribute *mtty_dev_attrs[] = {
1220         &dev_attr_sample_mtty_dev.attr,
1221         NULL,
1222 };
1223
1224 static const struct attribute_group mtty_dev_group = {
1225         .name  = "mtty_dev",
1226         .attrs = mtty_dev_attrs,
1227 };
1228
1229 static const struct attribute_group *mtty_dev_groups[] = {
1230         &mtty_dev_group,
1231         NULL,
1232 };
1233
1234 static ssize_t
1235 sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
1236                      char *buf)
1237 {
1238         if (mdev_from_dev(dev))
1239                 return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
1240
1241         return sprintf(buf, "\n");
1242 }
1243
1244 static DEVICE_ATTR_RO(sample_mdev_dev);
1245
1246 static struct attribute *mdev_dev_attrs[] = {
1247         &dev_attr_sample_mdev_dev.attr,
1248         NULL,
1249 };
1250
1251 static const struct attribute_group mdev_dev_group = {
1252         .name  = "vendor",
1253         .attrs = mdev_dev_attrs,
1254 };
1255
1256 static const struct attribute_group *mdev_dev_groups[] = {
1257         &mdev_dev_group,
1258         NULL,
1259 };
1260
1261 static ssize_t name_show(struct mdev_type *mtype,
1262                          struct mdev_type_attribute *attr, char *buf)
1263 {
1264         static const char *name_str[2] = { "Single port serial",
1265                                            "Dual port serial" };
1266
1267         return sysfs_emit(buf, "%s\n",
1268                           name_str[mtype_get_type_group_id(mtype)]);
1269 }
1270
1271 static MDEV_TYPE_ATTR_RO(name);
1272
1273 static ssize_t available_instances_show(struct mdev_type *mtype,
1274                                         struct mdev_type_attribute *attr,
1275                                         char *buf)
1276 {
1277         unsigned int ports = mtype_get_type_group_id(mtype) + 1;
1278
1279         return sprintf(buf, "%d\n", atomic_read(&mdev_avail_ports) / ports);
1280 }
1281
1282 static MDEV_TYPE_ATTR_RO(available_instances);
1283
1284 static ssize_t device_api_show(struct mdev_type *mtype,
1285                                struct mdev_type_attribute *attr, char *buf)
1286 {
1287         return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
1288 }
1289
1290 static MDEV_TYPE_ATTR_RO(device_api);
1291
1292 static struct attribute *mdev_types_attrs[] = {
1293         &mdev_type_attr_name.attr,
1294         &mdev_type_attr_device_api.attr,
1295         &mdev_type_attr_available_instances.attr,
1296         NULL,
1297 };
1298
1299 static struct attribute_group mdev_type_group1 = {
1300         .name  = "1",
1301         .attrs = mdev_types_attrs,
1302 };
1303
1304 static struct attribute_group mdev_type_group2 = {
1305         .name  = "2",
1306         .attrs = mdev_types_attrs,
1307 };
1308
1309 static struct attribute_group *mdev_type_groups[] = {
1310         &mdev_type_group1,
1311         &mdev_type_group2,
1312         NULL,
1313 };
1314
1315 static const struct vfio_device_ops mtty_dev_ops = {
1316         .name = "vfio-mtty",
1317         .read = mtty_read,
1318         .write = mtty_write,
1319         .ioctl = mtty_ioctl,
1320 };
1321
1322 static struct mdev_driver mtty_driver = {
1323         .driver = {
1324                 .name = "mtty",
1325                 .owner = THIS_MODULE,
1326                 .mod_name = KBUILD_MODNAME,
1327                 .dev_groups = mdev_dev_groups,
1328         },
1329         .probe = mtty_probe,
1330         .remove = mtty_remove,
1331 };
1332
1333 static const struct mdev_parent_ops mdev_fops = {
1334         .owner                  = THIS_MODULE,
1335         .device_driver          = &mtty_driver,
1336         .dev_attr_groups        = mtty_dev_groups,
1337         .supported_type_groups  = mdev_type_groups,
1338 };
1339
1340 static void mtty_device_release(struct device *dev)
1341 {
1342         dev_dbg(dev, "mtty: released\n");
1343 }
1344
1345 static int __init mtty_dev_init(void)
1346 {
1347         int ret = 0;
1348
1349         pr_info("mtty_dev: %s\n", __func__);
1350
1351         memset(&mtty_dev, 0, sizeof(mtty_dev));
1352
1353         idr_init(&mtty_dev.vd_idr);
1354
1355         ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK + 1,
1356                                   MTTY_NAME);
1357
1358         if (ret < 0) {
1359                 pr_err("Error: failed to register mtty_dev, err:%d\n", ret);
1360                 return ret;
1361         }
1362
1363         cdev_init(&mtty_dev.vd_cdev, &vd_fops);
1364         cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK + 1);
1365
1366         pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt));
1367
1368         ret = mdev_register_driver(&mtty_driver);
1369         if (ret)
1370                 goto err_cdev;
1371
1372         mtty_dev.vd_class = class_create(THIS_MODULE, MTTY_CLASS_NAME);
1373
1374         if (IS_ERR(mtty_dev.vd_class)) {
1375                 pr_err("Error: failed to register mtty_dev class\n");
1376                 ret = PTR_ERR(mtty_dev.vd_class);
1377                 goto err_driver;
1378         }
1379
1380         mtty_dev.dev.class = mtty_dev.vd_class;
1381         mtty_dev.dev.release = mtty_device_release;
1382         dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME);
1383
1384         ret = device_register(&mtty_dev.dev);
1385         if (ret)
1386                 goto err_class;
1387
1388         ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
1389         if (ret)
1390                 goto err_device;
1391         return 0;
1392
1393 err_device:
1394         device_unregister(&mtty_dev.dev);
1395 err_class:
1396         class_destroy(mtty_dev.vd_class);
1397 err_driver:
1398         mdev_unregister_driver(&mtty_driver);
1399 err_cdev:
1400         cdev_del(&mtty_dev.vd_cdev);
1401         unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1402         return ret;
1403 }
1404
1405 static void __exit mtty_dev_exit(void)
1406 {
1407         mtty_dev.dev.bus = NULL;
1408         mdev_unregister_device(&mtty_dev.dev);
1409
1410         device_unregister(&mtty_dev.dev);
1411         idr_destroy(&mtty_dev.vd_idr);
1412         mdev_unregister_driver(&mtty_driver);
1413         cdev_del(&mtty_dev.vd_cdev);
1414         unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
1415         class_destroy(mtty_dev.vd_class);
1416         mtty_dev.vd_class = NULL;
1417         pr_info("mtty_dev: Unloaded!\n");
1418 }
1419
1420 module_init(mtty_dev_init)
1421 module_exit(mtty_dev_exit)
1422
1423 MODULE_LICENSE("GPL v2");
1424 MODULE_INFO(supported, "Test driver that simulate serial port over PCI");
1425 MODULE_VERSION(VERSION_STRING);
1426 MODULE_AUTHOR(DRIVER_AUTHOR);