1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/device.h>
4 #include <linux/err.h>
5 #include <linux/errno.h>
6 #include <linux/fs.h>
7 #include <linux/fsi-sbefifo.h>
8 #include <linux/gfp.h>
9 #include <linux/idr.h>
10 #include <linux/kernel.h>
11 #include <linux/list.h>
12 #include <linux/miscdevice.h>
13 #include <linux/mm.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/fsi-occ.h>
17 #include <linux/of.h>
18 #include <linux/of_platform.h>
19 #include <linux/platform_device.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/uaccess.h>
23 #include <asm/unaligned.h>
24
25 #define OCC_SRAM_BYTES 4096
26 #define OCC_CMD_DATA_BYTES 4090
27 #define OCC_RESP_DATA_BYTES 4089
28
29 #define OCC_P9_SRAM_CMD_ADDR 0xFFFBE000
30 #define OCC_P9_SRAM_RSP_ADDR 0xFFFBF000
31
32 #define OCC_P10_SRAM_CMD_ADDR 0xFFFFD000
33 #define OCC_P10_SRAM_RSP_ADDR 0xFFFFE000
34
35 #define OCC_P10_SRAM_MODE 0x58 /* Normal mode, OCB channel 2 */
36
37 #define OCC_TIMEOUT_MS 1000
38 #define OCC_CMD_IN_PRG_WAIT_MS 50
39
40 enum versions { occ_p9, occ_p10 };
41
42 struct occ {
43 struct device *dev;
44 struct device *sbefifo;
45 char name[32];
46 int idx;
47 bool platform_hwmon;
48 u8 sequence_number;
49 void *buffer;
50 void *client_buffer;
51 size_t client_buffer_size;
52 size_t client_response_size;
53 enum versions version;
54 struct miscdevice mdev;
55 struct mutex occ_lock;
56 };
57
58 #define to_occ(x) container_of((x), struct occ, mdev)
59
60 struct occ_response {
61 u8 seq_no;
62 u8 cmd_type;
63 u8 return_status;
64 __be16 data_length;
65 u8 data[OCC_RESP_DATA_BYTES + 2]; /* two bytes checksum */
66 } __packed;
67
68 struct occ_client {
69 struct occ *occ;
70 struct mutex lock;
71 size_t data_size;
72 size_t read_offset;
73 u8 *buffer;
74 };
75
76 #define to_client(x) container_of((x), struct occ_client, xfr)
77
78 static DEFINE_IDA(occ_ida);
79
occ_open(struct inode * inode,struct file * file)80 static int occ_open(struct inode *inode, struct file *file)
81 {
82 struct occ_client *client = kzalloc(sizeof(*client), GFP_KERNEL);
83 struct miscdevice *mdev = file->private_data;
84 struct occ *occ = to_occ(mdev);
85
86 if (!client)
87 return -ENOMEM;
88
89 client->buffer = (u8 *)__get_free_page(GFP_KERNEL);
90 if (!client->buffer) {
91 kfree(client);
92 return -ENOMEM;
93 }
94
95 client->occ = occ;
96 mutex_init(&client->lock);
97 file->private_data = client;
98 get_device(occ->dev);
99
100 /* We allocate a 1-page buffer, make sure it all fits */
101 BUILD_BUG_ON((OCC_CMD_DATA_BYTES + 3) > PAGE_SIZE);
102 BUILD_BUG_ON((OCC_RESP_DATA_BYTES + 7) > PAGE_SIZE);
103
104 return 0;
105 }
106
occ_read(struct file * file,char __user * buf,size_t len,loff_t * offset)107 static ssize_t occ_read(struct file *file, char __user *buf, size_t len,
108 loff_t *offset)
109 {
110 struct occ_client *client = file->private_data;
111 ssize_t rc = 0;
112
113 if (!client)
114 return -ENODEV;
115
116 if (len > OCC_SRAM_BYTES)
117 return -EINVAL;
118
119 mutex_lock(&client->lock);
120
121 /* This should not be possible ... */
122 if (WARN_ON_ONCE(client->read_offset > client->data_size)) {
123 rc = -EIO;
124 goto done;
125 }
126
127 /* Grab how much data we have to read */
128 rc = min(len, client->data_size - client->read_offset);
129 if (copy_to_user(buf, client->buffer + client->read_offset, rc))
130 rc = -EFAULT;
131 else
132 client->read_offset += rc;
133
134 done:
135 mutex_unlock(&client->lock);
136
137 return rc;
138 }
139
occ_write(struct file * file,const char __user * buf,size_t len,loff_t * offset)140 static ssize_t occ_write(struct file *file, const char __user *buf,
141 size_t len, loff_t *offset)
142 {
143 struct occ_client *client = file->private_data;
144 size_t rlen, data_length;
145 ssize_t rc;
146 u8 *cmd;
147
148 if (!client)
149 return -ENODEV;
150
151 if (len > (OCC_CMD_DATA_BYTES + 3) || len < 3)
152 return -EINVAL;
153
154 mutex_lock(&client->lock);
155
156 /* Construct the command */
157 cmd = client->buffer;
158
159 /*
160 * Copy the user command (assume user data follows the occ command
161 * format)
162 * byte 0: command type
163 * bytes 1-2: data length (msb first)
164 * bytes 3-n: data
165 */
166 if (copy_from_user(&cmd[1], buf, len)) {
167 rc = -EFAULT;
168 goto done;
169 }
170
171 /* Extract data length */
172 data_length = (cmd[2] << 8) + cmd[3];
173 if (data_length > OCC_CMD_DATA_BYTES) {
174 rc = -EINVAL;
175 goto done;
176 }
177
178 /* Submit command; 4 bytes before the data and 2 bytes after */
179 rlen = PAGE_SIZE;
180 rc = fsi_occ_submit(client->occ->dev, cmd, data_length + 6, cmd,
181 &rlen);
182 if (rc)
183 goto done;
184
185 /* Set read tracking data */
186 client->data_size = rlen;
187 client->read_offset = 0;
188
189 /* Done */
190 rc = len;
191
192 done:
193 mutex_unlock(&client->lock);
194
195 return rc;
196 }
197
occ_release(struct inode * inode,struct file * file)198 static int occ_release(struct inode *inode, struct file *file)
199 {
200 struct occ_client *client = file->private_data;
201
202 put_device(client->occ->dev);
203 free_page((unsigned long)client->buffer);
204 kfree(client);
205
206 return 0;
207 }
208
209 static const struct file_operations occ_fops = {
210 .owner = THIS_MODULE,
211 .open = occ_open,
212 .read = occ_read,
213 .write = occ_write,
214 .release = occ_release,
215 };
216
occ_save_ffdc(struct occ * occ,__be32 * resp,size_t parsed_len,size_t resp_len)217 static void occ_save_ffdc(struct occ *occ, __be32 *resp, size_t parsed_len,
218 size_t resp_len)
219 {
220 if (resp_len > parsed_len) {
221 size_t dh = resp_len - parsed_len;
222 size_t ffdc_len = (dh - 1) * 4; /* SBE words are four bytes */
223 __be32 *ffdc = &resp[parsed_len];
224
225 if (ffdc_len > occ->client_buffer_size)
226 ffdc_len = occ->client_buffer_size;
227
228 memcpy(occ->client_buffer, ffdc, ffdc_len);
229 occ->client_response_size = ffdc_len;
230 }
231 }
232
occ_verify_checksum(struct occ * occ,struct occ_response * resp,u16 data_length)233 static int occ_verify_checksum(struct occ *occ, struct occ_response *resp,
234 u16 data_length)
235 {
236 /* Fetch the two bytes after the data for the checksum. */
237 u16 checksum_resp = get_unaligned_be16(&resp->data[data_length]);
238 u16 checksum;
239 u16 i;
240
241 checksum = resp->seq_no;
242 checksum += resp->cmd_type;
243 checksum += resp->return_status;
244 checksum += (data_length >> 8) + (data_length & 0xFF);
245
246 for (i = 0; i < data_length; ++i)
247 checksum += resp->data[i];
248
249 if (checksum != checksum_resp) {
250 dev_err(occ->dev, "Bad checksum: %04x!=%04x\n", checksum,
251 checksum_resp);
252 return -EBADE;
253 }
254
255 return 0;
256 }
257
occ_getsram(struct occ * occ,u32 offset,void * data,ssize_t len)258 static int occ_getsram(struct occ *occ, u32 offset, void *data, ssize_t len)
259 {
260 u32 data_len = ((len + 7) / 8) * 8; /* must be multiples of 8 B */
261 size_t cmd_len, parsed_len, resp_data_len;
262 size_t resp_len = OCC_MAX_RESP_WORDS;
263 __be32 *resp = occ->buffer;
264 __be32 cmd[6];
265 int idx = 0, rc;
266
267 /*
268 * Magic sequence to do SBE getsram command. SBE will fetch data from
269 * specified SRAM address.
270 */
271 switch (occ->version) {
272 default:
273 case occ_p9:
274 cmd_len = 5;
275 cmd[2] = cpu_to_be32(1); /* Normal mode */
276 cmd[3] = cpu_to_be32(OCC_P9_SRAM_RSP_ADDR + offset);
277 break;
278 case occ_p10:
279 idx = 1;
280 cmd_len = 6;
281 cmd[2] = cpu_to_be32(OCC_P10_SRAM_MODE);
282 cmd[3] = 0;
283 cmd[4] = cpu_to_be32(OCC_P10_SRAM_RSP_ADDR + offset);
284 break;
285 }
286
287 cmd[0] = cpu_to_be32(cmd_len);
288 cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_OCC_SRAM);
289 cmd[4 + idx] = cpu_to_be32(data_len);
290
291 rc = sbefifo_submit(occ->sbefifo, cmd, cmd_len, resp, &resp_len);
292 if (rc)
293 return rc;
294
295 rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_GET_OCC_SRAM,
296 resp, resp_len, &parsed_len);
297 if (rc > 0) {
298 dev_err(occ->dev, "SRAM read returned failure status: %08x\n",
299 rc);
300 occ_save_ffdc(occ, resp, parsed_len, resp_len);
301 return -ECOMM;
302 } else if (rc) {
303 return rc;
304 }
305
306 resp_data_len = be32_to_cpu(resp[parsed_len - 1]);
307 if (resp_data_len != data_len) {
308 dev_err(occ->dev, "SRAM read expected %d bytes got %zd\n",
309 data_len, resp_data_len);
310 rc = -EBADMSG;
311 } else {
312 memcpy(data, resp, len);
313 }
314
315 return rc;
316 }
317
occ_putsram(struct occ * occ,const void * data,ssize_t len,u8 seq_no,u16 checksum)318 static int occ_putsram(struct occ *occ, const void *data, ssize_t len,
319 u8 seq_no, u16 checksum)
320 {
321 u32 data_len = ((len + 7) / 8) * 8; /* must be multiples of 8 B */
322 size_t cmd_len, parsed_len, resp_data_len;
323 size_t resp_len = OCC_MAX_RESP_WORDS;
324 __be32 *buf = occ->buffer;
325 u8 *byte_buf;
326 int idx = 0, rc;
327
328 cmd_len = (occ->version == occ_p10) ? 6 : 5;
329 cmd_len += data_len >> 2;
330
331 /*
332 * Magic sequence to do SBE putsram command. SBE will transfer
333 * data to specified SRAM address.
334 */
335 buf[0] = cpu_to_be32(cmd_len);
336 buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
337
338 switch (occ->version) {
339 default:
340 case occ_p9:
341 buf[2] = cpu_to_be32(1); /* Normal mode */
342 buf[3] = cpu_to_be32(OCC_P9_SRAM_CMD_ADDR);
343 break;
344 case occ_p10:
345 idx = 1;
346 buf[2] = cpu_to_be32(OCC_P10_SRAM_MODE);
347 buf[3] = 0;
348 buf[4] = cpu_to_be32(OCC_P10_SRAM_CMD_ADDR);
349 break;
350 }
351
352 buf[4 + idx] = cpu_to_be32(data_len);
353 memcpy(&buf[5 + idx], data, len);
354
355 byte_buf = (u8 *)&buf[5 + idx];
356 /*
357 * Overwrite the first byte with our sequence number and the last two
358 * bytes with the checksum.
359 */
360 byte_buf[0] = seq_no;
361 byte_buf[len - 2] = checksum >> 8;
362 byte_buf[len - 1] = checksum & 0xff;
363
364 rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
365 if (rc)
366 return rc;
367
368 rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
369 buf, resp_len, &parsed_len);
370 if (rc > 0) {
371 dev_err(occ->dev, "SRAM write returned failure status: %08x\n",
372 rc);
373 occ_save_ffdc(occ, buf, parsed_len, resp_len);
374 return -ECOMM;
375 } else if (rc) {
376 return rc;
377 }
378
379 if (parsed_len != 1) {
380 dev_err(occ->dev, "SRAM write response length invalid: %zd\n",
381 parsed_len);
382 rc = -EBADMSG;
383 } else {
384 resp_data_len = be32_to_cpu(buf[0]);
385 if (resp_data_len != data_len) {
386 dev_err(occ->dev,
387 "SRAM write expected %d bytes got %zd\n",
388 data_len, resp_data_len);
389 rc = -EBADMSG;
390 }
391 }
392
393 return rc;
394 }
395
occ_trigger_attn(struct occ * occ)396 static int occ_trigger_attn(struct occ *occ)
397 {
398 __be32 *buf = occ->buffer;
399 size_t cmd_len, parsed_len, resp_data_len;
400 size_t resp_len = OCC_MAX_RESP_WORDS;
401 int idx = 0, rc;
402
403 switch (occ->version) {
404 default:
405 case occ_p9:
406 cmd_len = 7;
407 buf[2] = cpu_to_be32(3); /* Circular mode */
408 buf[3] = 0;
409 break;
410 case occ_p10:
411 idx = 1;
412 cmd_len = 8;
413 buf[2] = cpu_to_be32(0xd0); /* Circular mode, OCB Channel 1 */
414 buf[3] = 0;
415 buf[4] = 0;
416 break;
417 }
418
419 buf[0] = cpu_to_be32(cmd_len); /* Chip-op length in words */
420 buf[1] = cpu_to_be32(SBEFIFO_CMD_PUT_OCC_SRAM);
421 buf[4 + idx] = cpu_to_be32(8); /* Data length in bytes */
422 buf[5 + idx] = cpu_to_be32(0x20010000); /* Trigger OCC attention */
423 buf[6 + idx] = 0;
424
425 rc = sbefifo_submit(occ->sbefifo, buf, cmd_len, buf, &resp_len);
426 if (rc)
427 return rc;
428
429 rc = sbefifo_parse_status(occ->sbefifo, SBEFIFO_CMD_PUT_OCC_SRAM,
430 buf, resp_len, &parsed_len);
431 if (rc > 0) {
432 dev_err(occ->dev, "SRAM attn returned failure status: %08x\n",
433 rc);
434 occ_save_ffdc(occ, buf, parsed_len, resp_len);
435 return -ECOMM;
436 } else if (rc) {
437 return rc;
438 }
439
440 if (parsed_len != 1) {
441 dev_err(occ->dev, "SRAM attn response length invalid: %zd\n",
442 parsed_len);
443 rc = -EBADMSG;
444 } else {
445 resp_data_len = be32_to_cpu(buf[0]);
446 if (resp_data_len != 8) {
447 dev_err(occ->dev,
448 "SRAM attn expected 8 bytes got %zd\n",
449 resp_data_len);
450 rc = -EBADMSG;
451 }
452 }
453
454 return rc;
455 }
456
fsi_occ_response_not_ready(struct occ_response * resp,u8 seq_no,u8 cmd_type)457 static bool fsi_occ_response_not_ready(struct occ_response *resp, u8 seq_no,
458 u8 cmd_type)
459 {
460 return resp->return_status == OCC_RESP_CMD_IN_PRG ||
461 resp->return_status == OCC_RESP_CRIT_INIT ||
462 resp->seq_no != seq_no || resp->cmd_type != cmd_type;
463 }
464
fsi_occ_submit(struct device * dev,const void * request,size_t req_len,void * response,size_t * resp_len)465 int fsi_occ_submit(struct device *dev, const void *request, size_t req_len,
466 void *response, size_t *resp_len)
467 {
468 const unsigned long timeout = msecs_to_jiffies(OCC_TIMEOUT_MS);
469 const unsigned long wait_time =
470 msecs_to_jiffies(OCC_CMD_IN_PRG_WAIT_MS);
471 struct occ *occ = dev_get_drvdata(dev);
472 struct occ_response *resp = response;
473 size_t user_resp_len = *resp_len;
474 u8 seq_no;
475 u8 cmd_type;
476 u16 checksum = 0;
477 u16 resp_data_length;
478 const u8 *byte_request = (const u8 *)request;
479 unsigned long end;
480 int rc;
481 size_t i;
482
483 *resp_len = 0;
484
485 if (!occ)
486 return -ENODEV;
487
488 if (user_resp_len < 7) {
489 dev_dbg(dev, "Bad resplen %zd\n", user_resp_len);
490 return -EINVAL;
491 }
492
493 cmd_type = byte_request[1];
494
495 /* Checksum the request, ignoring first byte (sequence number). */
496 for (i = 1; i < req_len - 2; ++i)
497 checksum += byte_request[i];
498
499 rc = mutex_lock_interruptible(&occ->occ_lock);
500 if (rc)
501 return rc;
502
503 occ->client_buffer = response;
504 occ->client_buffer_size = user_resp_len;
505 occ->client_response_size = 0;
506
507 if (!occ->buffer) {
508 rc = -ENOENT;
509 goto done;
510 }
511
512 /*
513 * Get a sequence number and update the counter. Avoid a sequence
514 * number of 0 which would pass the response check below even if the
515 * OCC response is uninitialized. Any sequence number the user is
516 * trying to send is overwritten since this function is the only common
517 * interface to the OCC and therefore the only place we can guarantee
518 * unique sequence numbers.
519 */
520 seq_no = occ->sequence_number++;
521 if (!occ->sequence_number)
522 occ->sequence_number = 1;
523 checksum += seq_no;
524
525 rc = occ_putsram(occ, request, req_len, seq_no, checksum);
526 if (rc)
527 goto done;
528
529 rc = occ_trigger_attn(occ);
530 if (rc)
531 goto done;
532
533 end = jiffies + timeout;
534 while (true) {
535 /* Read occ response header */
536 rc = occ_getsram(occ, 0, resp, 8);
537 if (rc)
538 goto done;
539
540 if (fsi_occ_response_not_ready(resp, seq_no, cmd_type)) {
541 if (time_after(jiffies, end)) {
542 dev_err(occ->dev,
543 "resp timeout status=%02x seq=%d cmd=%d, our seq=%d cmd=%d\n",
544 resp->return_status, resp->seq_no,
545 resp->cmd_type, seq_no, cmd_type);
546 rc = -ETIMEDOUT;
547 goto done;
548 }
549
550 set_current_state(TASK_UNINTERRUPTIBLE);
551 schedule_timeout(wait_time);
552 } else {
553 /* Extract size of response data */
554 resp_data_length =
555 get_unaligned_be16(&resp->data_length);
556
557 /*
558 * Message size is data length + 5 bytes header + 2
559 * bytes checksum
560 */
561 if ((resp_data_length + 7) > user_resp_len) {
562 rc = -EMSGSIZE;
563 goto done;
564 }
565
566 /*
567 * Get the entire response including the header again,
568 * in case it changed
569 */
570 if (resp_data_length > 1) {
571 rc = occ_getsram(occ, 0, resp,
572 resp_data_length + 7);
573 if (rc)
574 goto done;
575
576 if (!fsi_occ_response_not_ready(resp, seq_no,
577 cmd_type))
578 break;
579 } else {
580 break;
581 }
582 }
583 }
584
585 dev_dbg(dev, "resp_status=%02x resp_data_len=%d\n",
586 resp->return_status, resp_data_length);
587
588 rc = occ_verify_checksum(occ, resp, resp_data_length);
589 if (rc)
590 goto done;
591
592 occ->client_response_size = resp_data_length + 7;
593
594 done:
595 *resp_len = occ->client_response_size;
596 mutex_unlock(&occ->occ_lock);
597
598 return rc;
599 }
600 EXPORT_SYMBOL_GPL(fsi_occ_submit);
601
occ_unregister_platform_child(struct device * dev,void * data)602 static int occ_unregister_platform_child(struct device *dev, void *data)
603 {
604 struct platform_device *hwmon_dev = to_platform_device(dev);
605
606 platform_device_unregister(hwmon_dev);
607
608 return 0;
609 }
610
occ_unregister_of_child(struct device * dev,void * data)611 static int occ_unregister_of_child(struct device *dev, void *data)
612 {
613 struct platform_device *hwmon_dev = to_platform_device(dev);
614
615 of_device_unregister(hwmon_dev);
616 if (dev->of_node)
617 of_node_clear_flag(dev->of_node, OF_POPULATED);
618
619 return 0;
620 }
621
occ_probe(struct platform_device * pdev)622 static int occ_probe(struct platform_device *pdev)
623 {
624 int rc;
625 u32 reg;
626 char child_name[32];
627 struct occ *occ;
628 struct platform_device *hwmon_dev = NULL;
629 struct device_node *hwmon_node;
630 struct device *dev = &pdev->dev;
631 struct platform_device_info hwmon_dev_info = {
632 .parent = dev,
633 .name = "occ-hwmon",
634 };
635
636 occ = devm_kzalloc(dev, sizeof(*occ), GFP_KERNEL);
637 if (!occ)
638 return -ENOMEM;
639
640 /* SBE words are always four bytes */
641 occ->buffer = kvmalloc(OCC_MAX_RESP_WORDS * 4, GFP_KERNEL);
642 if (!occ->buffer)
643 return -ENOMEM;
644
645 occ->version = (uintptr_t)of_device_get_match_data(dev);
646 occ->dev = dev;
647 occ->sbefifo = dev->parent;
648 /*
649 * Quickly derive a pseudo-random number from jiffies so that
650 * re-probing the driver doesn't accidentally overlap sequence numbers.
651 */
652 occ->sequence_number = (u8)((jiffies % 0xff) + 1);
653 mutex_init(&occ->occ_lock);
654
655 if (dev->of_node) {
656 rc = of_property_read_u32(dev->of_node, "reg", ®);
657 if (!rc) {
658 /* make sure we don't have a duplicate from dts */
659 occ->idx = ida_simple_get(&occ_ida, reg, reg + 1,
660 GFP_KERNEL);
661 if (occ->idx < 0)
662 occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
663 GFP_KERNEL);
664 } else {
665 occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX,
666 GFP_KERNEL);
667 }
668 } else {
669 occ->idx = ida_simple_get(&occ_ida, 1, INT_MAX, GFP_KERNEL);
670 }
671
672 platform_set_drvdata(pdev, occ);
673
674 snprintf(occ->name, sizeof(occ->name), "occ%d", occ->idx);
675 occ->mdev.fops = &occ_fops;
676 occ->mdev.minor = MISC_DYNAMIC_MINOR;
677 occ->mdev.name = occ->name;
678 occ->mdev.parent = dev;
679
680 rc = misc_register(&occ->mdev);
681 if (rc) {
682 dev_err(dev, "failed to register miscdevice: %d\n", rc);
683 ida_simple_remove(&occ_ida, occ->idx);
684 kvfree(occ->buffer);
685 return rc;
686 }
687
688 hwmon_node = of_get_child_by_name(dev->of_node, hwmon_dev_info.name);
689 if (hwmon_node) {
690 snprintf(child_name, sizeof(child_name), "%s.%d", hwmon_dev_info.name, occ->idx);
691 hwmon_dev = of_platform_device_create(hwmon_node, child_name, dev);
692 of_node_put(hwmon_node);
693 }
694
695 if (!hwmon_dev) {
696 occ->platform_hwmon = true;
697 hwmon_dev_info.id = occ->idx;
698 hwmon_dev = platform_device_register_full(&hwmon_dev_info);
699 if (IS_ERR(hwmon_dev))
700 dev_warn(dev, "failed to create hwmon device\n");
701 }
702
703 return 0;
704 }
705
occ_remove(struct platform_device * pdev)706 static int occ_remove(struct platform_device *pdev)
707 {
708 struct occ *occ = platform_get_drvdata(pdev);
709
710 misc_deregister(&occ->mdev);
711
712 mutex_lock(&occ->occ_lock);
713 kvfree(occ->buffer);
714 occ->buffer = NULL;
715 mutex_unlock(&occ->occ_lock);
716
717 if (occ->platform_hwmon)
718 device_for_each_child(&pdev->dev, NULL, occ_unregister_platform_child);
719 else
720 device_for_each_child(&pdev->dev, NULL, occ_unregister_of_child);
721
722 ida_simple_remove(&occ_ida, occ->idx);
723
724 return 0;
725 }
726
727 static const struct of_device_id occ_match[] = {
728 {
729 .compatible = "ibm,p9-occ",
730 .data = (void *)occ_p9
731 },
732 {
733 .compatible = "ibm,p10-occ",
734 .data = (void *)occ_p10
735 },
736 { },
737 };
738 MODULE_DEVICE_TABLE(of, occ_match);
739
740 static struct platform_driver occ_driver = {
741 .driver = {
742 .name = "occ",
743 .of_match_table = occ_match,
744 },
745 .probe = occ_probe,
746 .remove = occ_remove,
747 };
748
occ_init(void)749 static int occ_init(void)
750 {
751 return platform_driver_register(&occ_driver);
752 }
753
occ_exit(void)754 static void occ_exit(void)
755 {
756 platform_driver_unregister(&occ_driver);
757
758 ida_destroy(&occ_ida);
759 }
760
761 module_init(occ_init);
762 module_exit(occ_exit);
763
764 MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>");
765 MODULE_DESCRIPTION("BMC P9 OCC driver");
766 MODULE_LICENSE("GPL");
767