xref: /linux/drivers/mtd/devices/mtd_intel_dg.c (revision edd2b9832d604a234b60a4910c7496f351cd1e12)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright(c) 2019-2025, Intel Corporation. All rights reserved.
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/bits.h>
8 #include <linux/cleanup.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/intel_dg_nvm_aux.h>
12 #include <linux/io.h>
13 #include <linux/io-64-nonatomic-lo-hi.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/partitions.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/string.h>
20 #include <linux/slab.h>
21 #include <linux/sizes.h>
22 #include <linux/types.h>
23 
24 #define INTEL_DG_NVM_RPM_TIMEOUT_MS 500
25 
26 struct intel_dg_nvm {
27 	struct kref refcnt;
28 	struct mtd_info mtd;
29 	struct device *dev;
30 	struct mutex lock; /* region access lock */
31 	void __iomem *base;
32 	void __iomem *base2;
33 	bool non_posted_erase;
34 
35 	size_t size;
36 	unsigned int nregions;
37 	struct {
38 		const char *name;
39 		u8 id;
40 		u64 offset;
41 		u64 size;
42 		unsigned int is_readable:1;
43 		unsigned int is_writable:1;
44 	} regions[] __counted_by(nregions);
45 };
46 
47 #define NVM_TRIGGER_REG       0x00000000
48 #define NVM_VALSIG_REG        0x00000010
49 #define NVM_ADDRESS_REG       0x00000040
50 #define NVM_REGION_ID_REG     0x00000044
51 #define NVM_DEBUG_REG         0x00000000
52 /*
53  * [15:0]-Erase size = 0x0010 4K 0x0080 32K 0x0100 64K
54  * [23:16]-Reserved
55  * [31:24]-Erase MEM RegionID
56  */
57 #define NVM_ERASE_REG         0x00000048
58 #define NVM_ACCESS_ERROR_REG  0x00000070
59 #define NVM_ADDRESS_ERROR_REG 0x00000074
60 
61 /* Flash Valid Signature */
62 #define NVM_FLVALSIG          0x0FF0A55A
63 
64 #define NVM_MAP_ADDR_MASK     GENMASK(7, 0)
65 #define NVM_MAP_ADDR_SHIFT    0x00000004
66 
67 #define NVM_REGION_ID_DESCRIPTOR  0
68 /* Flash Region Base Address */
69 #define NVM_FRBA      0x40
70 /* Flash Region __n - Flash Descriptor Record */
71 #define NVM_FLREG(__n) (NVM_FRBA + ((__n) * 4))
72 /*  Flash Map 1 Register */
73 #define NVM_FLMAP1_REG  0x18
74 #define NVM_FLMSTR4_OFFSET 0x00C
75 
76 #define NVM_ACCESS_ERROR_PCIE_MASK 0x7
77 
78 #define NVM_FREG_BASE_MASK GENMASK(15, 0)
79 #define NVM_FREG_ADDR_MASK GENMASK(31, 16)
80 #define NVM_FREG_ADDR_SHIFT 12
81 #define NVM_FREG_MIN_REGION_SIZE 0xFFF
82 
83 #define NVM_NON_POSTED_ERASE_DONE BIT(23)
84 #define NVM_NON_POSTED_ERASE_DONE_ITER 3000
85 
86 static inline void idg_nvm_set_region_id(struct intel_dg_nvm *nvm, u8 region)
87 {
88 	iowrite32((u32)region, nvm->base + NVM_REGION_ID_REG);
89 }
90 
91 static inline u32 idg_nvm_error(struct intel_dg_nvm *nvm)
92 {
93 	void __iomem *base = nvm->base;
94 
95 	u32 reg = ioread32(base + NVM_ACCESS_ERROR_REG) & NVM_ACCESS_ERROR_PCIE_MASK;
96 
97 	/* reset error bits */
98 	if (reg)
99 		iowrite32(reg, base + NVM_ACCESS_ERROR_REG);
100 
101 	return reg;
102 }
103 
104 static inline u32 idg_nvm_read32(struct intel_dg_nvm *nvm, u32 address)
105 {
106 	void __iomem *base = nvm->base;
107 
108 	iowrite32(address, base + NVM_ADDRESS_REG);
109 
110 	return ioread32(base + NVM_TRIGGER_REG);
111 }
112 
113 static inline u64 idg_nvm_read64(struct intel_dg_nvm *nvm, u32 address)
114 {
115 	void __iomem *base = nvm->base;
116 
117 	iowrite32(address, base + NVM_ADDRESS_REG);
118 
119 	return readq(base + NVM_TRIGGER_REG);
120 }
121 
122 static void idg_nvm_write32(struct intel_dg_nvm *nvm, u32 address, u32 data)
123 {
124 	void __iomem *base = nvm->base;
125 
126 	iowrite32(address, base + NVM_ADDRESS_REG);
127 
128 	iowrite32(data, base + NVM_TRIGGER_REG);
129 }
130 
131 static void idg_nvm_write64(struct intel_dg_nvm *nvm, u32 address, u64 data)
132 {
133 	void __iomem *base = nvm->base;
134 
135 	iowrite32(address, base + NVM_ADDRESS_REG);
136 
137 	writeq(data, base + NVM_TRIGGER_REG);
138 }
139 
140 static int idg_nvm_get_access_map(struct intel_dg_nvm *nvm, u32 *access_map)
141 {
142 	u32 fmstr4_addr;
143 	u32 fmstr4;
144 	u32 flmap1;
145 	u32 fmba;
146 
147 	idg_nvm_set_region_id(nvm, NVM_REGION_ID_DESCRIPTOR);
148 
149 	flmap1 = idg_nvm_read32(nvm, NVM_FLMAP1_REG);
150 	if (idg_nvm_error(nvm))
151 		return -EIO;
152 	/* Get Flash Master Baser Address (FMBA) */
153 	fmba = (FIELD_GET(NVM_MAP_ADDR_MASK, flmap1) << NVM_MAP_ADDR_SHIFT);
154 	fmstr4_addr = fmba + NVM_FLMSTR4_OFFSET;
155 
156 	fmstr4 = idg_nvm_read32(nvm, fmstr4_addr);
157 	if (idg_nvm_error(nvm))
158 		return -EIO;
159 
160 	*access_map = fmstr4;
161 	return 0;
162 }
163 
164 /*
165  * Region read/write access encoded in the access map
166  * in the following order from the lower bit:
167  * [3:0] regions 12-15 read state
168  * [7:4] regions 12-15 write state
169  * [19:8] regions 0-11 read state
170  * [31:20] regions 0-11 write state
171  */
172 static bool idg_nvm_region_readable(u32 access_map, u8 region)
173 {
174 	if (region < 12)
175 		return access_map & BIT(region + 8); /* [19:8] */
176 	else
177 		return access_map & BIT(region - 12); /* [3:0] */
178 }
179 
180 static bool idg_nvm_region_writable(u32 access_map, u8 region)
181 {
182 	if (region < 12)
183 		return access_map & BIT(region + 20); /* [31:20] */
184 	else
185 		return access_map & BIT(region - 8); /* [7:4] */
186 }
187 
188 static int idg_nvm_is_valid(struct intel_dg_nvm *nvm)
189 {
190 	u32 is_valid;
191 
192 	idg_nvm_set_region_id(nvm, NVM_REGION_ID_DESCRIPTOR);
193 
194 	is_valid = idg_nvm_read32(nvm, NVM_VALSIG_REG);
195 	if (idg_nvm_error(nvm))
196 		return -EIO;
197 
198 	if (is_valid != NVM_FLVALSIG)
199 		return -ENODEV;
200 
201 	return 0;
202 }
203 
204 static unsigned int idg_nvm_get_region(const struct intel_dg_nvm *nvm, loff_t from)
205 {
206 	unsigned int i;
207 
208 	for (i = 0; i < nvm->nregions; i++) {
209 		if ((nvm->regions[i].offset + nvm->regions[i].size - 1) >= from &&
210 		    nvm->regions[i].offset <= from &&
211 		    nvm->regions[i].size != 0)
212 			break;
213 	}
214 
215 	return i;
216 }
217 
218 static ssize_t idg_nvm_rewrite_partial(struct intel_dg_nvm *nvm, loff_t to,
219 				       loff_t offset, size_t len, const u32 *newdata)
220 {
221 	u32 data = idg_nvm_read32(nvm, to);
222 
223 	if (idg_nvm_error(nvm))
224 		return -EIO;
225 
226 	memcpy((u8 *)&data + offset, newdata, len);
227 
228 	idg_nvm_write32(nvm, to, data);
229 	if (idg_nvm_error(nvm))
230 		return -EIO;
231 
232 	return len;
233 }
234 
235 static ssize_t idg_write(struct intel_dg_nvm *nvm, u8 region,
236 			 loff_t to, size_t len, const unsigned char *buf)
237 {
238 	size_t len_s = len;
239 	size_t to_shift;
240 	size_t len8;
241 	size_t len4;
242 	ssize_t ret;
243 	size_t to4;
244 	size_t i;
245 
246 	idg_nvm_set_region_id(nvm, region);
247 
248 	to4 = ALIGN_DOWN(to, sizeof(u32));
249 	to_shift = min(sizeof(u32) - ((size_t)to - to4), len);
250 	if (to - to4) {
251 		ret = idg_nvm_rewrite_partial(nvm, to4, to - to4, to_shift, (u32 *)&buf[0]);
252 		if (ret < 0)
253 			return ret;
254 
255 		buf += to_shift;
256 		to += to_shift;
257 		len_s -= to_shift;
258 	}
259 
260 	if (!IS_ALIGNED(to, sizeof(u64)) &&
261 	    ((to ^ (to + len_s)) & GENMASK(31, 10))) {
262 		/*
263 		 * Workaround reads/writes across 1k-aligned addresses
264 		 * (start u32 before 1k, end u32 after)
265 		 * as this fails on hardware.
266 		 */
267 		u32 data;
268 
269 		memcpy(&data, &buf[0], sizeof(u32));
270 		idg_nvm_write32(nvm, to, data);
271 		if (idg_nvm_error(nvm))
272 			return -EIO;
273 		buf += sizeof(u32);
274 		to += sizeof(u32);
275 		len_s -= sizeof(u32);
276 	}
277 
278 	len8 = ALIGN_DOWN(len_s, sizeof(u64));
279 	for (i = 0; i < len8; i += sizeof(u64)) {
280 		u64 data;
281 
282 		memcpy(&data, &buf[i], sizeof(u64));
283 		idg_nvm_write64(nvm, to + i, data);
284 		if (idg_nvm_error(nvm))
285 			return -EIO;
286 	}
287 
288 	len4 = len_s - len8;
289 	if (len4 >= sizeof(u32)) {
290 		u32 data;
291 
292 		memcpy(&data, &buf[i], sizeof(u32));
293 		idg_nvm_write32(nvm, to + i, data);
294 		if (idg_nvm_error(nvm))
295 			return -EIO;
296 		i += sizeof(u32);
297 		len4 -= sizeof(u32);
298 	}
299 
300 	if (len4 > 0) {
301 		ret = idg_nvm_rewrite_partial(nvm, to + i, 0, len4, (u32 *)&buf[i]);
302 		if (ret < 0)
303 			return ret;
304 	}
305 
306 	return len;
307 }
308 
309 static ssize_t idg_read(struct intel_dg_nvm *nvm, u8 region,
310 			loff_t from, size_t len, unsigned char *buf)
311 {
312 	size_t len_s = len;
313 	size_t from_shift;
314 	size_t from4;
315 	size_t len8;
316 	size_t len4;
317 	size_t i;
318 
319 	idg_nvm_set_region_id(nvm, region);
320 
321 	from4 = ALIGN_DOWN(from, sizeof(u32));
322 	from_shift = min(sizeof(u32) - ((size_t)from - from4), len);
323 
324 	if (from - from4) {
325 		u32 data = idg_nvm_read32(nvm, from4);
326 
327 		if (idg_nvm_error(nvm))
328 			return -EIO;
329 		memcpy(&buf[0], (u8 *)&data + (from - from4), from_shift);
330 		len_s -= from_shift;
331 		buf += from_shift;
332 		from += from_shift;
333 	}
334 
335 	if (!IS_ALIGNED(from, sizeof(u64)) &&
336 	    ((from ^ (from + len_s)) & GENMASK(31, 10))) {
337 		/*
338 		 * Workaround reads/writes across 1k-aligned addresses
339 		 * (start u32 before 1k, end u32 after)
340 		 * as this fails on hardware.
341 		 */
342 		u32 data = idg_nvm_read32(nvm, from);
343 
344 		if (idg_nvm_error(nvm))
345 			return -EIO;
346 		memcpy(&buf[0], &data, sizeof(data));
347 		len_s -= sizeof(u32);
348 		buf += sizeof(u32);
349 		from += sizeof(u32);
350 	}
351 
352 	len8 = ALIGN_DOWN(len_s, sizeof(u64));
353 	for (i = 0; i < len8; i += sizeof(u64)) {
354 		u64 data = idg_nvm_read64(nvm, from + i);
355 
356 		if (idg_nvm_error(nvm))
357 			return -EIO;
358 
359 		memcpy(&buf[i], &data, sizeof(data));
360 	}
361 
362 	len4 = len_s - len8;
363 	if (len4 >= sizeof(u32)) {
364 		u32 data = idg_nvm_read32(nvm, from + i);
365 
366 		if (idg_nvm_error(nvm))
367 			return -EIO;
368 		memcpy(&buf[i], &data, sizeof(data));
369 		i += sizeof(u32);
370 		len4 -= sizeof(u32);
371 	}
372 
373 	if (len4 > 0) {
374 		u32 data = idg_nvm_read32(nvm, from + i);
375 
376 		if (idg_nvm_error(nvm))
377 			return -EIO;
378 		memcpy(&buf[i], &data, len4);
379 	}
380 
381 	return len;
382 }
383 
384 static ssize_t
385 idg_erase(struct intel_dg_nvm *nvm, u8 region, loff_t from, u64 len, u64 *fail_addr)
386 {
387 	void __iomem *base2 = nvm->base2;
388 	void __iomem *base = nvm->base;
389 	const u32 block = 0x10;
390 	u32 iter = 0;
391 	u32 reg;
392 	u64 i;
393 
394 	for (i = 0; i < len; i += SZ_4K) {
395 		iowrite32(from + i, base + NVM_ADDRESS_REG);
396 		iowrite32(region << 24 | block, base + NVM_ERASE_REG);
397 		if (nvm->non_posted_erase) {
398 			/* Wait for Erase Done */
399 			reg = ioread32(base2 + NVM_DEBUG_REG);
400 			while (!(reg & NVM_NON_POSTED_ERASE_DONE) &&
401 			       ++iter < NVM_NON_POSTED_ERASE_DONE_ITER) {
402 				msleep(10);
403 				reg = ioread32(base2 + NVM_DEBUG_REG);
404 			}
405 			if (reg & NVM_NON_POSTED_ERASE_DONE) {
406 				/* Clear Erase Done */
407 				iowrite32(reg, base2 + NVM_DEBUG_REG);
408 			} else {
409 				*fail_addr = from + i;
410 				return -ETIME;
411 			}
412 		}
413 		/* Since the writes are via sgunit
414 		 * we cannot do back to back erases.
415 		 */
416 		msleep(50);
417 	}
418 	return len;
419 }
420 
421 static int intel_dg_nvm_init(struct intel_dg_nvm *nvm, struct device *device,
422 			     bool non_posted_erase)
423 {
424 	u32 access_map = 0;
425 	unsigned int i, n;
426 	int ret;
427 
428 	nvm->dev = device;
429 
430 	/* clean error register, previous errors are ignored */
431 	idg_nvm_error(nvm);
432 
433 	ret = idg_nvm_is_valid(nvm);
434 	if (ret) {
435 		dev_err(device, "The MEM is not valid %d\n", ret);
436 		return ret;
437 	}
438 
439 	if (idg_nvm_get_access_map(nvm, &access_map))
440 		return -EIO;
441 
442 	for (i = 0, n = 0; i < nvm->nregions; i++) {
443 		u32 address, base, limit, region;
444 		u8 id = nvm->regions[i].id;
445 
446 		address = NVM_FLREG(id);
447 		region = idg_nvm_read32(nvm, address);
448 
449 		base = FIELD_GET(NVM_FREG_BASE_MASK, region) << NVM_FREG_ADDR_SHIFT;
450 		limit = (FIELD_GET(NVM_FREG_ADDR_MASK, region) << NVM_FREG_ADDR_SHIFT) |
451 			NVM_FREG_MIN_REGION_SIZE;
452 
453 		dev_dbg(device, "[%d] %s: region: 0x%08X base: 0x%08x limit: 0x%08x\n",
454 			id, nvm->regions[i].name, region, base, limit);
455 
456 		if (base >= limit || (i > 0 && limit == 0)) {
457 			dev_dbg(device, "[%d] %s: disabled\n",
458 				id, nvm->regions[i].name);
459 			nvm->regions[i].is_readable = 0;
460 			continue;
461 		}
462 
463 		if (nvm->size < limit)
464 			nvm->size = limit;
465 
466 		nvm->regions[i].offset = base;
467 		nvm->regions[i].size = limit - base + 1;
468 		/* No write access to descriptor; mask it out*/
469 		nvm->regions[i].is_writable = idg_nvm_region_writable(access_map, id);
470 
471 		nvm->regions[i].is_readable = idg_nvm_region_readable(access_map, id);
472 		dev_dbg(device, "Registered, %s id=%d offset=%lld size=%lld rd=%d wr=%d\n",
473 			nvm->regions[i].name,
474 			nvm->regions[i].id,
475 			nvm->regions[i].offset,
476 			nvm->regions[i].size,
477 			nvm->regions[i].is_readable,
478 			nvm->regions[i].is_writable);
479 
480 		if (nvm->regions[i].is_readable)
481 			n++;
482 	}
483 
484 	nvm->non_posted_erase = non_posted_erase;
485 
486 	dev_dbg(device, "Registered %d regions\n", n);
487 	dev_dbg(device, "Non posted erase %d\n", nvm->non_posted_erase);
488 
489 	/* Need to add 1 to the amount of memory
490 	 * so it is reported as an even block
491 	 */
492 	nvm->size += 1;
493 
494 	return n;
495 }
496 
497 static int intel_dg_mtd_erase(struct mtd_info *mtd, struct erase_info *info)
498 {
499 	struct intel_dg_nvm *nvm = mtd->priv;
500 	size_t total_len;
501 	unsigned int idx;
502 	ssize_t bytes;
503 	loff_t from;
504 	size_t len;
505 	u8 region;
506 	u64 addr;
507 	int ret;
508 
509 	if (WARN_ON(!nvm))
510 		return -EINVAL;
511 
512 	if (!IS_ALIGNED(info->addr, SZ_4K) || !IS_ALIGNED(info->len, SZ_4K)) {
513 		dev_err(&mtd->dev, "unaligned erase %llx %llx\n",
514 			info->addr, info->len);
515 		info->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
516 		return -EINVAL;
517 	}
518 
519 	total_len = info->len;
520 	addr = info->addr;
521 
522 	ret = pm_runtime_resume_and_get(nvm->dev);
523 	if (ret < 0) {
524 		dev_err(&mtd->dev, "rpm: get failed %d\n", ret);
525 		return ret;
526 	}
527 
528 	ret = 0;
529 	guard(mutex)(&nvm->lock);
530 
531 	while (total_len > 0) {
532 		if (!IS_ALIGNED(addr, SZ_4K) || !IS_ALIGNED(total_len, SZ_4K)) {
533 			dev_err(&mtd->dev, "unaligned erase %llx %zx\n", addr, total_len);
534 			info->fail_addr = addr;
535 			ret = -ERANGE;
536 			break;
537 		}
538 
539 		idx = idg_nvm_get_region(nvm, addr);
540 		if (idx >= nvm->nregions) {
541 			dev_err(&mtd->dev, "out of range");
542 			info->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
543 			ret = -ERANGE;
544 			break;
545 		}
546 
547 		from = addr - nvm->regions[idx].offset;
548 		region = nvm->regions[idx].id;
549 		len = total_len;
550 		if (len > nvm->regions[idx].size - from)
551 			len = nvm->regions[idx].size - from;
552 
553 		dev_dbg(&mtd->dev, "erasing region[%d] %s from %llx len %zx\n",
554 			region, nvm->regions[idx].name, from, len);
555 
556 		bytes = idg_erase(nvm, region, from, len, &info->fail_addr);
557 		if (bytes < 0) {
558 			dev_dbg(&mtd->dev, "erase failed with %zd\n", bytes);
559 			info->fail_addr += nvm->regions[idx].offset;
560 			ret = bytes;
561 			break;
562 		}
563 
564 		addr += len;
565 		total_len -= len;
566 	}
567 
568 	pm_runtime_put_autosuspend(nvm->dev);
569 	return ret;
570 }
571 
572 static int intel_dg_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
573 			     size_t *retlen, u_char *buf)
574 {
575 	struct intel_dg_nvm *nvm = mtd->priv;
576 	unsigned int idx;
577 	ssize_t ret;
578 	u8 region;
579 
580 	if (WARN_ON(!nvm))
581 		return -EINVAL;
582 
583 	idx = idg_nvm_get_region(nvm, from);
584 
585 	dev_dbg(&mtd->dev, "reading region[%d] %s from %lld len %zd\n",
586 		nvm->regions[idx].id, nvm->regions[idx].name, from, len);
587 
588 	if (idx >= nvm->nregions) {
589 		dev_err(&mtd->dev, "out of range");
590 		return -ERANGE;
591 	}
592 
593 	from -= nvm->regions[idx].offset;
594 	region = nvm->regions[idx].id;
595 	if (len > nvm->regions[idx].size - from)
596 		len = nvm->regions[idx].size - from;
597 
598 	ret = pm_runtime_resume_and_get(nvm->dev);
599 	if (ret < 0) {
600 		dev_err(&mtd->dev, "rpm: get failed %zd\n", ret);
601 		return ret;
602 	}
603 
604 	guard(mutex)(&nvm->lock);
605 
606 	ret = idg_read(nvm, region, from, len, buf);
607 	if (ret < 0) {
608 		dev_dbg(&mtd->dev, "read failed with %zd\n", ret);
609 	} else {
610 		*retlen = ret;
611 		ret = 0;
612 	}
613 
614 	pm_runtime_put_autosuspend(nvm->dev);
615 	return ret;
616 }
617 
618 static int intel_dg_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
619 			      size_t *retlen, const u_char *buf)
620 {
621 	struct intel_dg_nvm *nvm = mtd->priv;
622 	unsigned int idx;
623 	ssize_t ret;
624 	u8 region;
625 
626 	if (WARN_ON(!nvm))
627 		return -EINVAL;
628 
629 	idx = idg_nvm_get_region(nvm, to);
630 
631 	dev_dbg(&mtd->dev, "writing region[%d] %s to %lld len %zd\n",
632 		nvm->regions[idx].id, nvm->regions[idx].name, to, len);
633 
634 	if (idx >= nvm->nregions) {
635 		dev_err(&mtd->dev, "out of range");
636 		return -ERANGE;
637 	}
638 
639 	to -= nvm->regions[idx].offset;
640 	region = nvm->regions[idx].id;
641 	if (len > nvm->regions[idx].size - to)
642 		len = nvm->regions[idx].size - to;
643 
644 	ret = pm_runtime_resume_and_get(nvm->dev);
645 	if (ret < 0) {
646 		dev_err(&mtd->dev, "rpm: get failed %zd\n", ret);
647 		return ret;
648 	}
649 
650 	guard(mutex)(&nvm->lock);
651 
652 	ret = idg_write(nvm, region, to, len, buf);
653 	if (ret < 0) {
654 		dev_dbg(&mtd->dev, "write failed with %zd\n", ret);
655 	} else {
656 		*retlen = ret;
657 		ret = 0;
658 	}
659 
660 	pm_runtime_put_autosuspend(nvm->dev);
661 	return ret;
662 }
663 
664 static void intel_dg_nvm_release(struct kref *kref)
665 {
666 	struct intel_dg_nvm *nvm = container_of(kref, struct intel_dg_nvm, refcnt);
667 	int i;
668 
669 	pr_debug("freeing intel_dg nvm\n");
670 	for (i = 0; i < nvm->nregions; i++)
671 		kfree(nvm->regions[i].name);
672 	mutex_destroy(&nvm->lock);
673 	kfree(nvm);
674 }
675 
676 static int intel_dg_mtd_get_device(struct mtd_info *mtd)
677 {
678 	struct mtd_info *master = mtd_get_master(mtd);
679 	struct intel_dg_nvm *nvm = master->priv;
680 
681 	if (WARN_ON(!nvm))
682 		return -EINVAL;
683 	pr_debug("get mtd %s %d\n", mtd->name, kref_read(&nvm->refcnt));
684 	kref_get(&nvm->refcnt);
685 
686 	return 0;
687 }
688 
689 static void intel_dg_mtd_put_device(struct mtd_info *mtd)
690 {
691 	struct mtd_info *master = mtd_get_master(mtd);
692 	struct intel_dg_nvm *nvm = master->priv;
693 
694 	if (WARN_ON(!nvm))
695 		return;
696 	pr_debug("put mtd %s %d\n", mtd->name, kref_read(&nvm->refcnt));
697 	kref_put(&nvm->refcnt, intel_dg_nvm_release);
698 }
699 
700 static int intel_dg_nvm_init_mtd(struct intel_dg_nvm *nvm, struct device *device,
701 				 unsigned int nparts, bool writable_override)
702 {
703 	struct mtd_partition *parts = NULL;
704 	unsigned int i, n;
705 	int ret;
706 
707 	dev_dbg(device, "registering with mtd\n");
708 
709 	nvm->mtd.owner = THIS_MODULE;
710 	nvm->mtd.dev.parent = device;
711 	nvm->mtd.flags = MTD_CAP_NORFLASH;
712 	nvm->mtd.type = MTD_DATAFLASH;
713 	nvm->mtd.priv = nvm;
714 	nvm->mtd._write = intel_dg_mtd_write;
715 	nvm->mtd._read = intel_dg_mtd_read;
716 	nvm->mtd._erase = intel_dg_mtd_erase;
717 	nvm->mtd._get_device = intel_dg_mtd_get_device;
718 	nvm->mtd._put_device = intel_dg_mtd_put_device;
719 	nvm->mtd.writesize = SZ_1; /* 1 byte granularity */
720 	nvm->mtd.erasesize = SZ_4K; /* 4K bytes granularity */
721 	nvm->mtd.size = nvm->size;
722 
723 	parts = kcalloc(nvm->nregions, sizeof(*parts), GFP_KERNEL);
724 	if (!parts)
725 		return -ENOMEM;
726 
727 	for (i = 0, n = 0; i < nvm->nregions && n < nparts; i++) {
728 		if (!nvm->regions[i].is_readable)
729 			continue;
730 		parts[n].name = nvm->regions[i].name;
731 		parts[n].offset  = nvm->regions[i].offset;
732 		parts[n].size = nvm->regions[i].size;
733 		if (!nvm->regions[i].is_writable && !writable_override)
734 			parts[n].mask_flags = MTD_WRITEABLE;
735 		n++;
736 	}
737 
738 	ret = mtd_device_register(&nvm->mtd, parts, n);
739 
740 	kfree(parts);
741 	return ret;
742 }
743 
744 static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
745 			      const struct auxiliary_device_id *aux_dev_id)
746 {
747 	struct intel_dg_nvm_dev *invm = auxiliary_dev_to_intel_dg_nvm_dev(aux_dev);
748 	struct intel_dg_nvm *nvm;
749 	struct device *device;
750 	unsigned int nregions;
751 	unsigned int i, n;
752 	int ret;
753 
754 	device = &aux_dev->dev;
755 
756 	/* count available regions */
757 	for (nregions = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
758 		if (invm->regions[i].name)
759 			nregions++;
760 	}
761 
762 	if (!nregions) {
763 		dev_err(device, "no regions defined\n");
764 		return -ENODEV;
765 	}
766 
767 	nvm = kzalloc(struct_size(nvm, regions, nregions), GFP_KERNEL);
768 	if (!nvm)
769 		return -ENOMEM;
770 
771 	kref_init(&nvm->refcnt);
772 	mutex_init(&nvm->lock);
773 
774 	for (n = 0, i = 0; i < INTEL_DG_NVM_REGIONS; i++) {
775 		if (!invm->regions[i].name)
776 			continue;
777 
778 		char *name = kasprintf(GFP_KERNEL, "%s.%s",
779 				       dev_name(&aux_dev->dev), invm->regions[i].name);
780 		if (!name)
781 			continue;
782 		nvm->regions[n].name = name;
783 		nvm->regions[n].id = i;
784 		n++;
785 	}
786 	nvm->nregions = n; /* in case where kasprintf fail */
787 
788 	ret = devm_pm_runtime_enable(device);
789 	if (ret < 0) {
790 		dev_err(device, "rpm: enable failed %d\n", ret);
791 		goto err_norpm;
792 	}
793 
794 	pm_runtime_set_autosuspend_delay(device, INTEL_DG_NVM_RPM_TIMEOUT_MS);
795 	pm_runtime_use_autosuspend(device);
796 
797 	ret = pm_runtime_resume_and_get(device);
798 	if (ret < 0) {
799 		dev_err(device, "rpm: get failed %d\n", ret);
800 		goto err_norpm;
801 	}
802 
803 	nvm->base = devm_ioremap_resource(device, &invm->bar);
804 	if (IS_ERR(nvm->base)) {
805 		ret = PTR_ERR(nvm->base);
806 		goto err;
807 	}
808 
809 	if (invm->non_posted_erase) {
810 		nvm->base2 = devm_ioremap_resource(device, &invm->bar2);
811 		if (IS_ERR(nvm->base2)) {
812 			ret = PTR_ERR(nvm->base2);
813 			goto err;
814 		}
815 	}
816 
817 	ret = intel_dg_nvm_init(nvm, device, invm->non_posted_erase);
818 	if (ret < 0) {
819 		dev_err(device, "cannot initialize nvm %d\n", ret);
820 		goto err;
821 	}
822 
823 	ret = intel_dg_nvm_init_mtd(nvm, device, ret, invm->writable_override);
824 	if (ret) {
825 		dev_err(device, "failed init mtd %d\n", ret);
826 		goto err;
827 	}
828 
829 	dev_set_drvdata(&aux_dev->dev, nvm);
830 
831 	pm_runtime_put(device);
832 	return 0;
833 
834 err:
835 	pm_runtime_put(device);
836 err_norpm:
837 	kref_put(&nvm->refcnt, intel_dg_nvm_release);
838 	return ret;
839 }
840 
841 static void intel_dg_mtd_remove(struct auxiliary_device *aux_dev)
842 {
843 	struct intel_dg_nvm *nvm = dev_get_drvdata(&aux_dev->dev);
844 
845 	if (!nvm)
846 		return;
847 
848 	mtd_device_unregister(&nvm->mtd);
849 
850 	dev_set_drvdata(&aux_dev->dev, NULL);
851 
852 	kref_put(&nvm->refcnt, intel_dg_nvm_release);
853 }
854 
855 static const struct auxiliary_device_id intel_dg_mtd_id_table[] = {
856 	{
857 		.name = "i915.nvm",
858 	},
859 	{
860 		.name = "xe.nvm",
861 	},
862 	{
863 		/* sentinel */
864 	}
865 };
866 MODULE_DEVICE_TABLE(auxiliary, intel_dg_mtd_id_table);
867 
868 static struct auxiliary_driver intel_dg_mtd_driver = {
869 	.probe  = intel_dg_mtd_probe,
870 	.remove = intel_dg_mtd_remove,
871 	.driver = {
872 		/* auxiliary_driver_register() sets .name to be the modname */
873 	},
874 	.id_table = intel_dg_mtd_id_table
875 };
876 module_auxiliary_driver(intel_dg_mtd_driver);
877 
878 MODULE_LICENSE("GPL");
879 MODULE_AUTHOR("Intel Corporation");
880 MODULE_DESCRIPTION("Intel DGFX MTD driver");
881