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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SCOM FSI Client device driver
4  *
5  * Copyright (C) IBM Corporation 2016
6  */
7 
8 #include <linux/fsi.h>
9 #include <linux/module.h>
10 #include <linux/cdev.h>
11 #include <linux/delay.h>
12 #include <linux/fs.h>
13 #include <linux/uaccess.h>
14 #include <linux/slab.h>
15 #include <linux/list.h>
16 
17 #include <uapi/linux/fsi.h>
18 
19 #define FSI_ENGID_SCOM		0x5
20 
21 /* SCOM engine register set */
22 #define SCOM_DATA0_REG		0x00
23 #define SCOM_DATA1_REG		0x04
24 #define SCOM_CMD_REG		0x08
25 #define SCOM_FSI2PIB_RESET_REG	0x18
26 #define SCOM_STATUS_REG		0x1C /* Read */
27 #define SCOM_PIB_RESET_REG	0x1C /* Write */
28 
29 /* Command register */
30 #define SCOM_WRITE_CMD		0x80000000
31 #define SCOM_READ_CMD		0x00000000
32 
33 /* Status register bits */
34 #define SCOM_STATUS_ERR_SUMMARY		0x80000000
35 #define SCOM_STATUS_PROTECTION		0x01000000
36 #define SCOM_STATUS_PARITY		0x04000000
37 #define SCOM_STATUS_PIB_ABORT		0x00100000
38 #define SCOM_STATUS_PIB_RESP_MASK	0x00007000
39 #define SCOM_STATUS_PIB_RESP_SHIFT	12
40 
41 #define SCOM_STATUS_ANY_ERR		(SCOM_STATUS_PROTECTION | \
42 					 SCOM_STATUS_PARITY |	  \
43 					 SCOM_STATUS_PIB_ABORT | \
44 					 SCOM_STATUS_PIB_RESP_MASK)
45 /* SCOM address encodings */
46 #define XSCOM_ADDR_IND_FLAG		BIT_ULL(63)
47 #define XSCOM_ADDR_INF_FORM1		BIT_ULL(60)
48 
49 /* SCOM indirect stuff */
50 #define XSCOM_ADDR_DIRECT_PART		0x7fffffffull
51 #define XSCOM_ADDR_INDIRECT_PART	0x000fffff00000000ull
52 #define XSCOM_DATA_IND_READ		BIT_ULL(63)
53 #define XSCOM_DATA_IND_COMPLETE		BIT_ULL(31)
54 #define XSCOM_DATA_IND_ERR_MASK		0x70000000ull
55 #define XSCOM_DATA_IND_ERR_SHIFT	28
56 #define XSCOM_DATA_IND_DATA		0x0000ffffull
57 #define XSCOM_DATA_IND_FORM1_DATA	0x000fffffffffffffull
58 #define XSCOM_ADDR_FORM1_LOW		0x000ffffffffull
59 #define XSCOM_ADDR_FORM1_HI		0xfff00000000ull
60 #define XSCOM_ADDR_FORM1_HI_SHIFT	20
61 
62 /* Retries */
63 #define SCOM_MAX_RETRIES		100	/* Retries on busy */
64 #define SCOM_MAX_IND_RETRIES		10	/* Retries indirect not ready */
65 
66 struct scom_device {
67 	struct list_head link;
68 	struct fsi_device *fsi_dev;
69 	struct device dev;
70 	struct cdev cdev;
71 	struct mutex lock;
72 	bool dead;
73 };
74 
__put_scom(struct scom_device * scom_dev,uint64_t value,uint32_t addr,uint32_t * status)75 static int __put_scom(struct scom_device *scom_dev, uint64_t value,
76 		      uint32_t addr, uint32_t *status)
77 {
78 	__be32 data, raw_status;
79 	int rc;
80 
81 	data = cpu_to_be32((value >> 32) & 0xffffffff);
82 	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
83 				sizeof(uint32_t));
84 	if (rc)
85 		return rc;
86 
87 	data = cpu_to_be32(value & 0xffffffff);
88 	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
89 				sizeof(uint32_t));
90 	if (rc)
91 		return rc;
92 
93 	data = cpu_to_be32(SCOM_WRITE_CMD | addr);
94 	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
95 				sizeof(uint32_t));
96 	if (rc)
97 		return rc;
98 	rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status,
99 			     sizeof(uint32_t));
100 	if (rc)
101 		return rc;
102 	*status = be32_to_cpu(raw_status);
103 
104 	return 0;
105 }
106 
__get_scom(struct scom_device * scom_dev,uint64_t * value,uint32_t addr,uint32_t * status)107 static int __get_scom(struct scom_device *scom_dev, uint64_t *value,
108 		      uint32_t addr, uint32_t *status)
109 {
110 	__be32 data, raw_status;
111 	int rc;
112 
113 
114 	*value = 0ULL;
115 	data = cpu_to_be32(SCOM_READ_CMD | addr);
116 	rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
117 				sizeof(uint32_t));
118 	if (rc)
119 		return rc;
120 	rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status,
121 			     sizeof(uint32_t));
122 	if (rc)
123 		return rc;
124 
125 	/*
126 	 * Read the data registers even on error, so we don't have
127 	 * to interpret the status register here.
128 	 */
129 	rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
130 				sizeof(uint32_t));
131 	if (rc)
132 		return rc;
133 	*value |= (uint64_t)be32_to_cpu(data) << 32;
134 	rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
135 				sizeof(uint32_t));
136 	if (rc)
137 		return rc;
138 	*value |= be32_to_cpu(data);
139 	*status = be32_to_cpu(raw_status);
140 
141 	return rc;
142 }
143 
put_indirect_scom_form0(struct scom_device * scom,uint64_t value,uint64_t addr,uint32_t * status)144 static int put_indirect_scom_form0(struct scom_device *scom, uint64_t value,
145 				   uint64_t addr, uint32_t *status)
146 {
147 	uint64_t ind_data, ind_addr;
148 	int rc, retries, err = 0;
149 
150 	if (value & ~XSCOM_DATA_IND_DATA)
151 		return -EINVAL;
152 
153 	ind_addr = addr & XSCOM_ADDR_DIRECT_PART;
154 	ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | value;
155 	rc = __put_scom(scom, ind_data, ind_addr, status);
156 	if (rc || (*status & SCOM_STATUS_ANY_ERR))
157 		return rc;
158 
159 	for (retries = 0; retries < SCOM_MAX_IND_RETRIES; retries++) {
160 		rc = __get_scom(scom, &ind_data, addr, status);
161 		if (rc || (*status & SCOM_STATUS_ANY_ERR))
162 			return rc;
163 
164 		err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT;
165 		*status = err << SCOM_STATUS_PIB_RESP_SHIFT;
166 		if ((ind_data & XSCOM_DATA_IND_COMPLETE) || (err != SCOM_PIB_BLOCKED))
167 			return 0;
168 
169 		msleep(1);
170 	}
171 	return rc;
172 }
173 
put_indirect_scom_form1(struct scom_device * scom,uint64_t value,uint64_t addr,uint32_t * status)174 static int put_indirect_scom_form1(struct scom_device *scom, uint64_t value,
175 				   uint64_t addr, uint32_t *status)
176 {
177 	uint64_t ind_data, ind_addr;
178 
179 	if (value & ~XSCOM_DATA_IND_FORM1_DATA)
180 		return -EINVAL;
181 
182 	ind_addr = addr & XSCOM_ADDR_FORM1_LOW;
183 	ind_data = value | (addr & XSCOM_ADDR_FORM1_HI) << XSCOM_ADDR_FORM1_HI_SHIFT;
184 	return __put_scom(scom, ind_data, ind_addr, status);
185 }
186 
get_indirect_scom_form0(struct scom_device * scom,uint64_t * value,uint64_t addr,uint32_t * status)187 static int get_indirect_scom_form0(struct scom_device *scom, uint64_t *value,
188 				   uint64_t addr, uint32_t *status)
189 {
190 	uint64_t ind_data, ind_addr;
191 	int rc, retries, err = 0;
192 
193 	ind_addr = addr & XSCOM_ADDR_DIRECT_PART;
194 	ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | XSCOM_DATA_IND_READ;
195 	rc = __put_scom(scom, ind_data, ind_addr, status);
196 	if (rc || (*status & SCOM_STATUS_ANY_ERR))
197 		return rc;
198 
199 	for (retries = 0; retries < SCOM_MAX_IND_RETRIES; retries++) {
200 		rc = __get_scom(scom, &ind_data, addr, status);
201 		if (rc || (*status & SCOM_STATUS_ANY_ERR))
202 			return rc;
203 
204 		err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT;
205 		*status = err << SCOM_STATUS_PIB_RESP_SHIFT;
206 		*value = ind_data & XSCOM_DATA_IND_DATA;
207 
208 		if ((ind_data & XSCOM_DATA_IND_COMPLETE) || (err != SCOM_PIB_BLOCKED))
209 			return 0;
210 
211 		msleep(1);
212 	}
213 	return rc;
214 }
215 
raw_put_scom(struct scom_device * scom,uint64_t value,uint64_t addr,uint32_t * status)216 static int raw_put_scom(struct scom_device *scom, uint64_t value,
217 			uint64_t addr, uint32_t *status)
218 {
219 	if (addr & XSCOM_ADDR_IND_FLAG) {
220 		if (addr & XSCOM_ADDR_INF_FORM1)
221 			return put_indirect_scom_form1(scom, value, addr, status);
222 		else
223 			return put_indirect_scom_form0(scom, value, addr, status);
224 	} else
225 		return __put_scom(scom, value, addr, status);
226 }
227 
raw_get_scom(struct scom_device * scom,uint64_t * value,uint64_t addr,uint32_t * status)228 static int raw_get_scom(struct scom_device *scom, uint64_t *value,
229 			uint64_t addr, uint32_t *status)
230 {
231 	if (addr & XSCOM_ADDR_IND_FLAG) {
232 		if (addr & XSCOM_ADDR_INF_FORM1)
233 			return -ENXIO;
234 		return get_indirect_scom_form0(scom, value, addr, status);
235 	} else
236 		return __get_scom(scom, value, addr, status);
237 }
238 
handle_fsi2pib_status(struct scom_device * scom,uint32_t status)239 static int handle_fsi2pib_status(struct scom_device *scom, uint32_t status)
240 {
241 	uint32_t dummy = -1;
242 
243 	if (status & SCOM_STATUS_PROTECTION)
244 		return -EPERM;
245 	if (status & SCOM_STATUS_PARITY) {
246 		fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
247 				 sizeof(uint32_t));
248 		return -EIO;
249 	}
250 	/* Return -EBUSY on PIB abort to force a retry */
251 	if (status & SCOM_STATUS_PIB_ABORT)
252 		return -EBUSY;
253 	return 0;
254 }
255 
handle_pib_status(struct scom_device * scom,uint8_t status)256 static int handle_pib_status(struct scom_device *scom, uint8_t status)
257 {
258 	uint32_t dummy = -1;
259 
260 	if (status == SCOM_PIB_SUCCESS)
261 		return 0;
262 	if (status == SCOM_PIB_BLOCKED)
263 		return -EBUSY;
264 
265 	/* Reset the bridge */
266 	fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
267 			 sizeof(uint32_t));
268 
269 	switch(status) {
270 	case SCOM_PIB_OFFLINE:
271 		return -ENODEV;
272 	case SCOM_PIB_BAD_ADDR:
273 		return -ENXIO;
274 	case SCOM_PIB_TIMEOUT:
275 		return -ETIMEDOUT;
276 	case SCOM_PIB_PARTIAL:
277 	case SCOM_PIB_CLK_ERR:
278 	case SCOM_PIB_PARITY_ERR:
279 	default:
280 		return -EIO;
281 	}
282 }
283 
put_scom(struct scom_device * scom,uint64_t value,uint64_t addr)284 static int put_scom(struct scom_device *scom, uint64_t value,
285 		    uint64_t addr)
286 {
287 	uint32_t status, dummy = -1;
288 	int rc, retries;
289 
290 	for (retries = 0; retries < SCOM_MAX_RETRIES; retries++) {
291 		rc = raw_put_scom(scom, value, addr, &status);
292 		if (rc) {
293 			/* Try resetting the bridge if FSI fails */
294 			if (rc != -ENODEV && retries == 0) {
295 				fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG,
296 						 &dummy, sizeof(uint32_t));
297 				rc = -EBUSY;
298 			} else
299 				return rc;
300 		} else
301 			rc = handle_fsi2pib_status(scom, status);
302 		if (rc && rc != -EBUSY)
303 			break;
304 		if (rc == 0) {
305 			rc = handle_pib_status(scom,
306 					       (status & SCOM_STATUS_PIB_RESP_MASK)
307 					       >> SCOM_STATUS_PIB_RESP_SHIFT);
308 			if (rc && rc != -EBUSY)
309 				break;
310 		}
311 		if (rc == 0)
312 			break;
313 		msleep(1);
314 	}
315 	return rc;
316 }
317 
get_scom(struct scom_device * scom,uint64_t * value,uint64_t addr)318 static int get_scom(struct scom_device *scom, uint64_t *value,
319 		    uint64_t addr)
320 {
321 	uint32_t status, dummy = -1;
322 	int rc, retries;
323 
324 	for (retries = 0; retries < SCOM_MAX_RETRIES; retries++) {
325 		rc = raw_get_scom(scom, value, addr, &status);
326 		if (rc) {
327 			/* Try resetting the bridge if FSI fails */
328 			if (rc != -ENODEV && retries == 0) {
329 				fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG,
330 						 &dummy, sizeof(uint32_t));
331 				rc = -EBUSY;
332 			} else
333 				return rc;
334 		} else
335 			rc = handle_fsi2pib_status(scom, status);
336 		if (rc && rc != -EBUSY)
337 			break;
338 		if (rc == 0) {
339 			rc = handle_pib_status(scom,
340 					       (status & SCOM_STATUS_PIB_RESP_MASK)
341 					       >> SCOM_STATUS_PIB_RESP_SHIFT);
342 			if (rc && rc != -EBUSY)
343 				break;
344 		}
345 		if (rc == 0)
346 			break;
347 		msleep(1);
348 	}
349 	return rc;
350 }
351 
scom_read(struct file * filep,char __user * buf,size_t len,loff_t * offset)352 static ssize_t scom_read(struct file *filep, char __user *buf, size_t len,
353 			 loff_t *offset)
354 {
355 	struct scom_device *scom = filep->private_data;
356 	struct device *dev = &scom->fsi_dev->dev;
357 	uint64_t val;
358 	int rc;
359 
360 	if (len != sizeof(uint64_t))
361 		return -EINVAL;
362 
363 	mutex_lock(&scom->lock);
364 	if (scom->dead)
365 		rc = -ENODEV;
366 	else
367 		rc = get_scom(scom, &val, *offset);
368 	mutex_unlock(&scom->lock);
369 	if (rc) {
370 		dev_dbg(dev, "get_scom fail:%d\n", rc);
371 		return rc;
372 	}
373 
374 	rc = copy_to_user(buf, &val, len);
375 	if (rc)
376 		dev_dbg(dev, "copy to user failed:%d\n", rc);
377 
378 	return rc ? rc : len;
379 }
380 
scom_write(struct file * filep,const char __user * buf,size_t len,loff_t * offset)381 static ssize_t scom_write(struct file *filep, const char __user *buf,
382 			  size_t len, loff_t *offset)
383 {
384 	int rc;
385 	struct scom_device *scom = filep->private_data;
386 	struct device *dev = &scom->fsi_dev->dev;
387 	uint64_t val;
388 
389 	if (len != sizeof(uint64_t))
390 		return -EINVAL;
391 
392 	rc = copy_from_user(&val, buf, len);
393 	if (rc) {
394 		dev_dbg(dev, "copy from user failed:%d\n", rc);
395 		return -EINVAL;
396 	}
397 
398 	mutex_lock(&scom->lock);
399 	if (scom->dead)
400 		rc = -ENODEV;
401 	else
402 		rc = put_scom(scom, val, *offset);
403 	mutex_unlock(&scom->lock);
404 	if (rc) {
405 		dev_dbg(dev, "put_scom failed with:%d\n", rc);
406 		return rc;
407 	}
408 
409 	return len;
410 }
411 
scom_llseek(struct file * file,loff_t offset,int whence)412 static loff_t scom_llseek(struct file *file, loff_t offset, int whence)
413 {
414 	switch (whence) {
415 	case SEEK_CUR:
416 		break;
417 	case SEEK_SET:
418 		file->f_pos = offset;
419 		break;
420 	default:
421 		return -EINVAL;
422 	}
423 
424 	return offset;
425 }
426 
raw_convert_status(struct scom_access * acc,uint32_t status)427 static void raw_convert_status(struct scom_access *acc, uint32_t status)
428 {
429 	acc->pib_status = (status & SCOM_STATUS_PIB_RESP_MASK) >>
430 		SCOM_STATUS_PIB_RESP_SHIFT;
431 	acc->intf_errors = 0;
432 
433 	if (status & SCOM_STATUS_PROTECTION)
434 		acc->intf_errors |= SCOM_INTF_ERR_PROTECTION;
435 	else if (status & SCOM_STATUS_PARITY)
436 		acc->intf_errors |= SCOM_INTF_ERR_PARITY;
437 	else if (status & SCOM_STATUS_PIB_ABORT)
438 		acc->intf_errors |= SCOM_INTF_ERR_ABORT;
439 	else if (status & SCOM_STATUS_ERR_SUMMARY)
440 		acc->intf_errors |= SCOM_INTF_ERR_UNKNOWN;
441 }
442 
scom_raw_read(struct scom_device * scom,void __user * argp)443 static int scom_raw_read(struct scom_device *scom, void __user *argp)
444 {
445 	struct scom_access acc;
446 	uint32_t status;
447 	int rc;
448 
449 	if (copy_from_user(&acc, argp, sizeof(struct scom_access)))
450 		return -EFAULT;
451 
452 	rc = raw_get_scom(scom, &acc.data, acc.addr, &status);
453 	if (rc)
454 		return rc;
455 	raw_convert_status(&acc, status);
456 	if (copy_to_user(argp, &acc, sizeof(struct scom_access)))
457 		return -EFAULT;
458 	return 0;
459 }
460 
scom_raw_write(struct scom_device * scom,void __user * argp)461 static int scom_raw_write(struct scom_device *scom, void __user *argp)
462 {
463 	u64 prev_data, mask, data;
464 	struct scom_access acc;
465 	uint32_t status;
466 	int rc;
467 
468 	if (copy_from_user(&acc, argp, sizeof(struct scom_access)))
469 		return -EFAULT;
470 
471 	if (acc.mask) {
472 		rc = raw_get_scom(scom, &prev_data, acc.addr, &status);
473 		if (rc)
474 			return rc;
475 		if (status & SCOM_STATUS_ANY_ERR)
476 			goto fail;
477 		mask = acc.mask;
478 	} else {
479 		prev_data = mask = -1ull;
480 	}
481 	data = (prev_data & ~mask) | (acc.data & mask);
482 	rc = raw_put_scom(scom, data, acc.addr, &status);
483 	if (rc)
484 		return rc;
485  fail:
486 	raw_convert_status(&acc, status);
487 	if (copy_to_user(argp, &acc, sizeof(struct scom_access)))
488 		return -EFAULT;
489 	return 0;
490 }
491 
scom_reset(struct scom_device * scom,void __user * argp)492 static int scom_reset(struct scom_device *scom, void __user *argp)
493 {
494 	uint32_t flags, dummy = -1;
495 	int rc = 0;
496 
497 	if (get_user(flags, (__u32 __user *)argp))
498 		return -EFAULT;
499 	if (flags & SCOM_RESET_PIB)
500 		rc = fsi_device_write(scom->fsi_dev, SCOM_PIB_RESET_REG, &dummy,
501 				      sizeof(uint32_t));
502 	if (!rc && (flags & (SCOM_RESET_PIB | SCOM_RESET_INTF)))
503 		rc = fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
504 				      sizeof(uint32_t));
505 	return rc;
506 }
507 
scom_check(struct scom_device * scom,void __user * argp)508 static int scom_check(struct scom_device *scom, void __user *argp)
509 {
510 	/* Still need to find out how to get "protected" */
511 	return put_user(SCOM_CHECK_SUPPORTED, (__u32 __user *)argp);
512 }
513 
scom_ioctl(struct file * file,unsigned int cmd,unsigned long arg)514 static long scom_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
515 {
516 	struct scom_device *scom = file->private_data;
517 	void __user *argp = (void __user *)arg;
518 	int rc = -ENOTTY;
519 
520 	mutex_lock(&scom->lock);
521 	if (scom->dead) {
522 		mutex_unlock(&scom->lock);
523 		return -ENODEV;
524 	}
525 	switch(cmd) {
526 	case FSI_SCOM_CHECK:
527 		rc = scom_check(scom, argp);
528 		break;
529 	case FSI_SCOM_READ:
530 		rc = scom_raw_read(scom, argp);
531 		break;
532 	case FSI_SCOM_WRITE:
533 		rc = scom_raw_write(scom, argp);
534 		break;
535 	case FSI_SCOM_RESET:
536 		rc = scom_reset(scom, argp);
537 		break;
538 	}
539 	mutex_unlock(&scom->lock);
540 	return rc;
541 }
542 
scom_open(struct inode * inode,struct file * file)543 static int scom_open(struct inode *inode, struct file *file)
544 {
545 	struct scom_device *scom = container_of(inode->i_cdev, struct scom_device, cdev);
546 
547 	file->private_data = scom;
548 
549 	return 0;
550 }
551 
552 static const struct file_operations scom_fops = {
553 	.owner		= THIS_MODULE,
554 	.open		= scom_open,
555 	.llseek		= scom_llseek,
556 	.read		= scom_read,
557 	.write		= scom_write,
558 	.unlocked_ioctl	= scom_ioctl,
559 };
560 
scom_free(struct device * dev)561 static void scom_free(struct device *dev)
562 {
563 	struct scom_device *scom = container_of(dev, struct scom_device, dev);
564 
565 	put_device(&scom->fsi_dev->dev);
566 	kfree(scom);
567 }
568 
scom_probe(struct device * dev)569 static int scom_probe(struct device *dev)
570 {
571 	struct fsi_device *fsi_dev = to_fsi_dev(dev);
572 	struct scom_device *scom;
573 	int rc, didx;
574 
575 	scom = kzalloc(sizeof(*scom), GFP_KERNEL);
576 	if (!scom)
577 		return -ENOMEM;
578 	dev_set_drvdata(dev, scom);
579 	mutex_init(&scom->lock);
580 
581 	/* Grab a reference to the device (parent of our cdev), we'll drop it later */
582 	if (!get_device(dev)) {
583 		kfree(scom);
584 		return -ENODEV;
585 	}
586 	scom->fsi_dev = fsi_dev;
587 
588 	/* Create chardev for userspace access */
589 	scom->dev.type = &fsi_cdev_type;
590 	scom->dev.parent = dev;
591 	scom->dev.release = scom_free;
592 	device_initialize(&scom->dev);
593 
594 	/* Allocate a minor in the FSI space */
595 	rc = fsi_get_new_minor(fsi_dev, fsi_dev_scom, &scom->dev.devt, &didx);
596 	if (rc)
597 		goto err;
598 
599 	dev_set_name(&scom->dev, "scom%d", didx);
600 	cdev_init(&scom->cdev, &scom_fops);
601 	rc = cdev_device_add(&scom->cdev, &scom->dev);
602 	if (rc) {
603 		dev_err(dev, "Error %d creating char device %s\n",
604 			rc, dev_name(&scom->dev));
605 		goto err_free_minor;
606 	}
607 
608 	return 0;
609  err_free_minor:
610 	fsi_free_minor(scom->dev.devt);
611  err:
612 	put_device(&scom->dev);
613 	return rc;
614 }
615 
scom_remove(struct device * dev)616 static int scom_remove(struct device *dev)
617 {
618 	struct scom_device *scom = dev_get_drvdata(dev);
619 
620 	mutex_lock(&scom->lock);
621 	scom->dead = true;
622 	mutex_unlock(&scom->lock);
623 	cdev_device_del(&scom->cdev, &scom->dev);
624 	fsi_free_minor(scom->dev.devt);
625 	put_device(&scom->dev);
626 
627 	return 0;
628 }
629 
630 static struct fsi_device_id scom_ids[] = {
631 	{
632 		.engine_type = FSI_ENGID_SCOM,
633 		.version = FSI_VERSION_ANY,
634 	},
635 	{ 0 }
636 };
637 
638 static struct fsi_driver scom_drv = {
639 	.id_table = scom_ids,
640 	.drv = {
641 		.name = "scom",
642 		.bus = &fsi_bus_type,
643 		.probe = scom_probe,
644 		.remove = scom_remove,
645 	}
646 };
647 
scom_init(void)648 static int scom_init(void)
649 {
650 	return fsi_driver_register(&scom_drv);
651 }
652 
scom_exit(void)653 static void scom_exit(void)
654 {
655 	fsi_driver_unregister(&scom_drv);
656 }
657 
658 module_init(scom_init);
659 module_exit(scom_exit);
660 MODULE_LICENSE("GPL");
661