xref: /linux/drivers/bus/mhi/host/init.c (revision bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
4  *
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/debugfs.h>
9 #include <linux/device.h>
10 #include <linux/dma-direction.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/idr.h>
13 #include <linux/interrupt.h>
14 #include <linux/list.h>
15 #include <linux/mhi.h>
16 #include <linux/mod_devicetable.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/vmalloc.h>
20 #include <linux/wait.h>
21 #include "internal.h"
22 
23 #define CREATE_TRACE_POINTS
24 #include "trace.h"
25 
26 static DEFINE_IDA(mhi_controller_ida);
27 
28 #undef mhi_ee
29 #undef mhi_ee_end
30 
31 #define mhi_ee(a, b)		[MHI_EE_##a] = b,
32 #define mhi_ee_end(a, b)	[MHI_EE_##a] = b,
33 
34 const char * const mhi_ee_str[MHI_EE_MAX] = {
35 	MHI_EE_LIST
36 };
37 
38 #undef dev_st_trans
39 #undef dev_st_trans_end
40 
41 #define dev_st_trans(a, b)	[DEV_ST_TRANSITION_##a] = b,
42 #define dev_st_trans_end(a, b)	[DEV_ST_TRANSITION_##a] = b,
43 
44 const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
45 	DEV_ST_TRANSITION_LIST
46 };
47 
48 #undef ch_state_type
49 #undef ch_state_type_end
50 
51 #define ch_state_type(a, b)	[MHI_CH_STATE_TYPE_##a] = b,
52 #define ch_state_type_end(a, b)	[MHI_CH_STATE_TYPE_##a] = b,
53 
54 const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX] = {
55 	MHI_CH_STATE_TYPE_LIST
56 };
57 
58 #undef mhi_pm_state
59 #undef mhi_pm_state_end
60 
61 #define mhi_pm_state(a, b)	[MHI_PM_STATE_##a] = b,
62 #define mhi_pm_state_end(a, b)	[MHI_PM_STATE_##a] = b,
63 
64 static const char * const mhi_pm_state_str[] = {
65 	MHI_PM_STATE_LIST
66 };
67 
68 const char *to_mhi_pm_state_str(u32 state)
69 {
70 	int index;
71 
72 	if (state)
73 		index = __fls(state);
74 
75 	if (!state || index >= ARRAY_SIZE(mhi_pm_state_str))
76 		return "Invalid State";
77 
78 	return mhi_pm_state_str[index];
79 }
80 
81 static ssize_t serial_number_show(struct device *dev,
82 				  struct device_attribute *attr,
83 				  char *buf)
84 {
85 	struct mhi_device *mhi_dev = to_mhi_device(dev);
86 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
87 
88 	return sysfs_emit(buf, "Serial Number: %u\n",
89 			mhi_cntrl->serial_number);
90 }
91 static DEVICE_ATTR_RO(serial_number);
92 
93 static ssize_t oem_pk_hash_show(struct device *dev,
94 				struct device_attribute *attr,
95 				char *buf)
96 {
97 	struct mhi_device *mhi_dev = to_mhi_device(dev);
98 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
99 	u32 hash_segment[MHI_MAX_OEM_PK_HASH_SEGMENTS];
100 	int i, cnt = 0, ret;
101 
102 	for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++) {
103 		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i), &hash_segment[i]);
104 		if (ret) {
105 			dev_err(dev, "Could not capture OEM PK HASH\n");
106 			return ret;
107 		}
108 	}
109 
110 	for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++)
111 		cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n", i, hash_segment[i]);
112 
113 	return cnt;
114 }
115 static DEVICE_ATTR_RO(oem_pk_hash);
116 
117 static ssize_t soc_reset_store(struct device *dev,
118 			       struct device_attribute *attr,
119 			       const char *buf,
120 			       size_t count)
121 {
122 	struct mhi_device *mhi_dev = to_mhi_device(dev);
123 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
124 
125 	mhi_soc_reset(mhi_cntrl);
126 	return count;
127 }
128 static DEVICE_ATTR_WO(soc_reset);
129 
130 static ssize_t trigger_edl_store(struct device *dev,
131 			       struct device_attribute *attr,
132 			       const char *buf, size_t count)
133 {
134 	struct mhi_device *mhi_dev = to_mhi_device(dev);
135 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
136 	unsigned long val;
137 	int ret;
138 
139 	ret = kstrtoul(buf, 10, &val);
140 	if (ret < 0)
141 		return ret;
142 
143 	if (!val)
144 		return -EINVAL;
145 
146 	ret = mhi_cntrl->edl_trigger(mhi_cntrl);
147 	if (ret)
148 		return ret;
149 
150 	return count;
151 }
152 static DEVICE_ATTR_WO(trigger_edl);
153 
154 static struct attribute *mhi_dev_attrs[] = {
155 	&dev_attr_serial_number.attr,
156 	&dev_attr_oem_pk_hash.attr,
157 	&dev_attr_soc_reset.attr,
158 	NULL,
159 };
160 ATTRIBUTE_GROUPS(mhi_dev);
161 
162 /* MHI protocol requires the transfer ring to be aligned with ring length */
163 static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
164 				  struct mhi_ring *ring,
165 				  u64 len)
166 {
167 	ring->alloc_size = len + (len - 1);
168 	ring->pre_aligned = dma_alloc_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
169 					       &ring->dma_handle, GFP_KERNEL);
170 	if (!ring->pre_aligned)
171 		return -ENOMEM;
172 
173 	ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);
174 	ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);
175 
176 	return 0;
177 }
178 
179 static void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)
180 {
181 	int i;
182 	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
183 
184 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
185 		if (mhi_event->offload_ev)
186 			continue;
187 
188 		free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
189 	}
190 
191 	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
192 }
193 
194 static int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
195 {
196 	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
197 	unsigned long irq_flags = IRQF_SHARED | IRQF_NO_SUSPEND;
198 	int i, ret;
199 
200 	/* if controller driver has set irq_flags, use it */
201 	if (mhi_cntrl->irq_flags)
202 		irq_flags = mhi_cntrl->irq_flags;
203 
204 	/* Setup BHI_INTVEC IRQ */
205 	ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handler,
206 				   mhi_intvec_threaded_handler,
207 				   irq_flags,
208 				   "bhi", mhi_cntrl);
209 	if (ret)
210 		return ret;
211 	/*
212 	 * IRQs should be enabled during mhi_async_power_up(), so disable them explicitly here.
213 	 * Due to the use of IRQF_SHARED flag as default while requesting IRQs, we assume that
214 	 * IRQ_NOAUTOEN is not applicable.
215 	 */
216 	disable_irq(mhi_cntrl->irq[0]);
217 
218 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
219 		if (mhi_event->offload_ev)
220 			continue;
221 
222 		if (mhi_event->irq >= mhi_cntrl->nr_irqs) {
223 			dev_err(mhi_cntrl->cntrl_dev, "irq %d not available for event ring\n",
224 				mhi_event->irq);
225 			ret = -EINVAL;
226 			goto error_request;
227 		}
228 
229 		ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
230 				  mhi_irq_handler,
231 				  irq_flags,
232 				  "mhi", mhi_event);
233 		if (ret) {
234 			dev_err(mhi_cntrl->cntrl_dev, "Error requesting irq:%d for ev:%d\n",
235 				mhi_cntrl->irq[mhi_event->irq], i);
236 			goto error_request;
237 		}
238 
239 		disable_irq(mhi_cntrl->irq[mhi_event->irq]);
240 	}
241 
242 	return 0;
243 
244 error_request:
245 	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
246 		if (mhi_event->offload_ev)
247 			continue;
248 
249 		free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
250 	}
251 	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
252 
253 	return ret;
254 }
255 
256 static void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl)
257 {
258 	int i;
259 	struct mhi_ctxt *mhi_ctxt = mhi_cntrl->mhi_ctxt;
260 	struct mhi_cmd *mhi_cmd;
261 	struct mhi_event *mhi_event;
262 	struct mhi_ring *ring;
263 
264 	mhi_cmd = mhi_cntrl->mhi_cmd;
265 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++) {
266 		ring = &mhi_cmd->ring;
267 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
268 				  ring->pre_aligned, ring->dma_handle);
269 		ring->base = NULL;
270 		ring->iommu_base = 0;
271 	}
272 
273 	dma_free_coherent(mhi_cntrl->cntrl_dev,
274 			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
275 			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
276 
277 	mhi_event = mhi_cntrl->mhi_event;
278 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
279 		if (mhi_event->offload_ev)
280 			continue;
281 
282 		ring = &mhi_event->ring;
283 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
284 				  ring->pre_aligned, ring->dma_handle);
285 		ring->base = NULL;
286 		ring->iommu_base = 0;
287 	}
288 
289 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->er_ctxt) *
290 			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
291 			  mhi_ctxt->er_ctxt_addr);
292 
293 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->chan_ctxt) *
294 			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
295 			  mhi_ctxt->chan_ctxt_addr);
296 
297 	kfree(mhi_ctxt);
298 	mhi_cntrl->mhi_ctxt = NULL;
299 }
300 
301 static int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
302 {
303 	struct mhi_ctxt *mhi_ctxt;
304 	struct mhi_chan_ctxt *chan_ctxt;
305 	struct mhi_event_ctxt *er_ctxt;
306 	struct mhi_cmd_ctxt *cmd_ctxt;
307 	struct mhi_chan *mhi_chan;
308 	struct mhi_event *mhi_event;
309 	struct mhi_cmd *mhi_cmd;
310 	u32 tmp;
311 	int ret = -ENOMEM, i;
312 
313 	atomic_set(&mhi_cntrl->dev_wake, 0);
314 	atomic_set(&mhi_cntrl->pending_pkts, 0);
315 
316 	mhi_ctxt = kzalloc_obj(*mhi_ctxt);
317 	if (!mhi_ctxt)
318 		return -ENOMEM;
319 
320 	/* Setup channel ctxt */
321 	mhi_ctxt->chan_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
322 						 sizeof(*mhi_ctxt->chan_ctxt) *
323 						 mhi_cntrl->max_chan,
324 						 &mhi_ctxt->chan_ctxt_addr,
325 						 GFP_KERNEL);
326 	if (!mhi_ctxt->chan_ctxt)
327 		goto error_alloc_chan_ctxt;
328 
329 	mhi_chan = mhi_cntrl->mhi_chan;
330 	chan_ctxt = mhi_ctxt->chan_ctxt;
331 	for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
332 		/* Skip if it is an offload channel */
333 		if (mhi_chan->offload_ch)
334 			continue;
335 
336 		tmp = le32_to_cpu(chan_ctxt->chcfg);
337 		tmp &= ~CHAN_CTX_CHSTATE_MASK;
338 		tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
339 		tmp &= ~CHAN_CTX_BRSTMODE_MASK;
340 		tmp |= FIELD_PREP(CHAN_CTX_BRSTMODE_MASK, mhi_chan->db_cfg.brstmode);
341 		tmp &= ~CHAN_CTX_POLLCFG_MASK;
342 		tmp |= FIELD_PREP(CHAN_CTX_POLLCFG_MASK, mhi_chan->db_cfg.pollcfg);
343 		chan_ctxt->chcfg = cpu_to_le32(tmp);
344 
345 		chan_ctxt->chtype = cpu_to_le32(mhi_chan->type);
346 		chan_ctxt->erindex = cpu_to_le32(mhi_chan->er_index);
347 
348 		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
349 		mhi_chan->tre_ring.db_addr = (void __iomem *)&chan_ctxt->wp;
350 	}
351 
352 	/* Setup event context */
353 	mhi_ctxt->er_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
354 					       sizeof(*mhi_ctxt->er_ctxt) *
355 					       mhi_cntrl->total_ev_rings,
356 					       &mhi_ctxt->er_ctxt_addr,
357 					       GFP_KERNEL);
358 	if (!mhi_ctxt->er_ctxt)
359 		goto error_alloc_er_ctxt;
360 
361 	er_ctxt = mhi_ctxt->er_ctxt;
362 	mhi_event = mhi_cntrl->mhi_event;
363 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
364 		     mhi_event++) {
365 		struct mhi_ring *ring = &mhi_event->ring;
366 
367 		/* Skip if it is an offload event */
368 		if (mhi_event->offload_ev)
369 			continue;
370 
371 		tmp = le32_to_cpu(er_ctxt->intmod);
372 		tmp &= ~EV_CTX_INTMODC_MASK;
373 		tmp &= ~EV_CTX_INTMODT_MASK;
374 		tmp |= FIELD_PREP(EV_CTX_INTMODT_MASK, mhi_event->intmod);
375 		er_ctxt->intmod = cpu_to_le32(tmp);
376 
377 		er_ctxt->ertype = cpu_to_le32(MHI_ER_TYPE_VALID);
378 		er_ctxt->msivec = cpu_to_le32(mhi_event->irq);
379 		mhi_event->db_cfg.db_mode = true;
380 
381 		ring->el_size = sizeof(struct mhi_ring_element);
382 		ring->len = ring->el_size * ring->elements;
383 		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
384 		if (ret)
385 			goto error_alloc_er;
386 
387 		/*
388 		 * If the read pointer equals to the write pointer, then the
389 		 * ring is empty
390 		 */
391 		ring->rp = ring->wp = ring->base;
392 		er_ctxt->rbase = cpu_to_le64(ring->iommu_base);
393 		er_ctxt->rp = er_ctxt->wp = er_ctxt->rbase;
394 		er_ctxt->rlen = cpu_to_le64(ring->len);
395 		ring->ctxt_wp = &er_ctxt->wp;
396 	}
397 
398 	/* Setup cmd context */
399 	ret = -ENOMEM;
400 	mhi_ctxt->cmd_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
401 						sizeof(*mhi_ctxt->cmd_ctxt) *
402 						NR_OF_CMD_RINGS,
403 						&mhi_ctxt->cmd_ctxt_addr,
404 						GFP_KERNEL);
405 	if (!mhi_ctxt->cmd_ctxt)
406 		goto error_alloc_er;
407 
408 	mhi_cmd = mhi_cntrl->mhi_cmd;
409 	cmd_ctxt = mhi_ctxt->cmd_ctxt;
410 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
411 		struct mhi_ring *ring = &mhi_cmd->ring;
412 
413 		ring->el_size = sizeof(struct mhi_ring_element);
414 		ring->elements = CMD_EL_PER_RING;
415 		ring->len = ring->el_size * ring->elements;
416 		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
417 		if (ret)
418 			goto error_alloc_cmd;
419 
420 		ring->rp = ring->wp = ring->base;
421 		cmd_ctxt->rbase = cpu_to_le64(ring->iommu_base);
422 		cmd_ctxt->rp = cmd_ctxt->wp = cmd_ctxt->rbase;
423 		cmd_ctxt->rlen = cpu_to_le64(ring->len);
424 		ring->ctxt_wp = &cmd_ctxt->wp;
425 	}
426 
427 	mhi_cntrl->mhi_ctxt = mhi_ctxt;
428 
429 	return 0;
430 
431 error_alloc_cmd:
432 	for (--i, --mhi_cmd; i >= 0; i--, mhi_cmd--) {
433 		struct mhi_ring *ring = &mhi_cmd->ring;
434 
435 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
436 				  ring->pre_aligned, ring->dma_handle);
437 	}
438 	dma_free_coherent(mhi_cntrl->cntrl_dev,
439 			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
440 			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
441 	i = mhi_cntrl->total_ev_rings;
442 	mhi_event = mhi_cntrl->mhi_event + i;
443 
444 error_alloc_er:
445 	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
446 		struct mhi_ring *ring = &mhi_event->ring;
447 
448 		if (mhi_event->offload_ev)
449 			continue;
450 
451 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
452 				  ring->pre_aligned, ring->dma_handle);
453 	}
454 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->er_ctxt) *
455 			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
456 			  mhi_ctxt->er_ctxt_addr);
457 
458 error_alloc_er_ctxt:
459 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->chan_ctxt) *
460 			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
461 			  mhi_ctxt->chan_ctxt_addr);
462 
463 error_alloc_chan_ctxt:
464 	kfree(mhi_ctxt);
465 
466 	return ret;
467 }
468 
469 int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
470 {
471 	u32 val;
472 	int i, ret;
473 	struct mhi_chan *mhi_chan;
474 	struct mhi_event *mhi_event;
475 	void __iomem *base = mhi_cntrl->regs;
476 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
477 	struct {
478 		u32 offset;
479 		u32 val;
480 	} reg_info[] = {
481 		{
482 			CCABAP_HIGHER,
483 			upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
484 		},
485 		{
486 			CCABAP_LOWER,
487 			lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
488 		},
489 		{
490 			ECABAP_HIGHER,
491 			upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
492 		},
493 		{
494 			ECABAP_LOWER,
495 			lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
496 		},
497 		{
498 			CRCBAP_HIGHER,
499 			upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
500 		},
501 		{
502 			CRCBAP_LOWER,
503 			lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
504 		},
505 		{
506 			MHICTRLBASE_HIGHER,
507 			upper_32_bits(mhi_cntrl->iova_start),
508 		},
509 		{
510 			MHICTRLBASE_LOWER,
511 			lower_32_bits(mhi_cntrl->iova_start),
512 		},
513 		{
514 			MHIDATABASE_HIGHER,
515 			upper_32_bits(mhi_cntrl->iova_start),
516 		},
517 		{
518 			MHIDATABASE_LOWER,
519 			lower_32_bits(mhi_cntrl->iova_start),
520 		},
521 		{
522 			MHICTRLLIMIT_HIGHER,
523 			upper_32_bits(mhi_cntrl->iova_stop),
524 		},
525 		{
526 			MHICTRLLIMIT_LOWER,
527 			lower_32_bits(mhi_cntrl->iova_stop),
528 		},
529 		{
530 			MHIDATALIMIT_HIGHER,
531 			upper_32_bits(mhi_cntrl->iova_stop),
532 		},
533 		{
534 			MHIDATALIMIT_LOWER,
535 			lower_32_bits(mhi_cntrl->iova_stop),
536 		},
537 		{0, 0}
538 	};
539 
540 	dev_dbg(dev, "Initializing MHI registers\n");
541 
542 	/* Read channel db offset */
543 	ret = mhi_get_channel_doorbell_offset(mhi_cntrl, &val);
544 	if (ret)
545 		return ret;
546 
547 	if (val >= mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)) {
548 		dev_err(dev, "CHDB offset: 0x%x is out of range: 0x%zx\n",
549 			val, mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB));
550 		return -ERANGE;
551 	}
552 
553 	/* Setup wake db */
554 	mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
555 	mhi_cntrl->wake_set = false;
556 
557 	/* Setup channel db address for each channel in tre_ring */
558 	mhi_chan = mhi_cntrl->mhi_chan;
559 	for (i = 0; i < mhi_cntrl->max_chan; i++, val += 8, mhi_chan++)
560 		mhi_chan->tre_ring.db_addr = base + val;
561 
562 	/* Read event ring db offset */
563 	ret = mhi_read_reg(mhi_cntrl, base, ERDBOFF, &val);
564 	if (ret) {
565 		dev_err(dev, "Unable to read ERDBOFF register\n");
566 		return -EIO;
567 	}
568 
569 	if (val >= mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings)) {
570 		dev_err(dev, "ERDB offset: 0x%x is out of range: 0x%zx\n",
571 			val, mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings));
572 		return -ERANGE;
573 	}
574 
575 	/* Setup event db address for each ev_ring */
576 	mhi_event = mhi_cntrl->mhi_event;
577 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
578 		if (mhi_event->offload_ev)
579 			continue;
580 
581 		mhi_event->ring.db_addr = base + val;
582 	}
583 
584 	/* Setup DB register for primary CMD rings */
585 	mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER;
586 
587 	/* Write to MMIO registers */
588 	for (i = 0; reg_info[i].offset; i++)
589 		mhi_write_reg(mhi_cntrl, base, reg_info[i].offset,
590 			      reg_info[i].val);
591 
592 	ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NER_MASK,
593 				  mhi_cntrl->total_ev_rings);
594 	if (ret) {
595 		dev_err(dev, "Unable to write MHICFG register\n");
596 		return ret;
597 	}
598 
599 	ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NHWER_MASK,
600 				  mhi_cntrl->hw_ev_rings);
601 	if (ret) {
602 		dev_err(dev, "Unable to write MHICFG register\n");
603 		return ret;
604 	}
605 
606 	return 0;
607 }
608 
609 void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
610 			  struct mhi_chan *mhi_chan)
611 {
612 	struct mhi_ring *buf_ring;
613 	struct mhi_ring *tre_ring;
614 	struct mhi_chan_ctxt *chan_ctxt;
615 	u32 tmp;
616 
617 	buf_ring = &mhi_chan->buf_ring;
618 	tre_ring = &mhi_chan->tre_ring;
619 	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
620 
621 	if (!chan_ctxt->rbase) /* Already uninitialized */
622 		return;
623 
624 	dma_free_coherent(mhi_cntrl->cntrl_dev, tre_ring->alloc_size,
625 			  tre_ring->pre_aligned, tre_ring->dma_handle);
626 	vfree(buf_ring->base);
627 
628 	buf_ring->base = tre_ring->base = NULL;
629 	tre_ring->ctxt_wp = NULL;
630 	chan_ctxt->rbase = 0;
631 	chan_ctxt->rlen = 0;
632 	chan_ctxt->rp = 0;
633 	chan_ctxt->wp = 0;
634 
635 	tmp = le32_to_cpu(chan_ctxt->chcfg);
636 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
637 	tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
638 	chan_ctxt->chcfg = cpu_to_le32(tmp);
639 
640 	/* Update to all cores */
641 	smp_wmb();
642 }
643 
644 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
645 		       struct mhi_chan *mhi_chan)
646 {
647 	struct mhi_ring *buf_ring;
648 	struct mhi_ring *tre_ring;
649 	struct mhi_chan_ctxt *chan_ctxt;
650 	u32 tmp;
651 	int ret;
652 
653 	buf_ring = &mhi_chan->buf_ring;
654 	tre_ring = &mhi_chan->tre_ring;
655 	tre_ring->el_size = sizeof(struct mhi_ring_element);
656 	tre_ring->len = tre_ring->el_size * tre_ring->elements;
657 	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
658 	ret = mhi_alloc_aligned_ring(mhi_cntrl, tre_ring, tre_ring->len);
659 	if (ret)
660 		return -ENOMEM;
661 
662 	buf_ring->el_size = sizeof(struct mhi_buf_info);
663 	buf_ring->len = buf_ring->el_size * buf_ring->elements;
664 	buf_ring->base = vzalloc(buf_ring->len);
665 
666 	if (!buf_ring->base) {
667 		dma_free_coherent(mhi_cntrl->cntrl_dev, tre_ring->alloc_size,
668 				  tre_ring->pre_aligned, tre_ring->dma_handle);
669 		return -ENOMEM;
670 	}
671 
672 	tmp = le32_to_cpu(chan_ctxt->chcfg);
673 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
674 	tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_ENABLED);
675 	chan_ctxt->chcfg = cpu_to_le32(tmp);
676 
677 	chan_ctxt->rbase = cpu_to_le64(tre_ring->iommu_base);
678 	chan_ctxt->rp = chan_ctxt->wp = chan_ctxt->rbase;
679 	chan_ctxt->rlen = cpu_to_le64(tre_ring->len);
680 	tre_ring->ctxt_wp = &chan_ctxt->wp;
681 
682 	tre_ring->rp = tre_ring->wp = tre_ring->base;
683 	buf_ring->rp = buf_ring->wp = buf_ring->base;
684 	mhi_chan->db_cfg.db_mode = 1;
685 
686 	/* Update to all cores */
687 	smp_wmb();
688 
689 	return 0;
690 }
691 
692 static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
693 			const struct mhi_controller_config *config)
694 {
695 	struct mhi_event *mhi_event;
696 	const struct mhi_event_config *event_cfg;
697 	struct device *dev = mhi_cntrl->cntrl_dev;
698 	int i, num;
699 
700 	num = config->num_events;
701 	mhi_cntrl->total_ev_rings = num;
702 	mhi_cntrl->mhi_event = kzalloc_objs(*mhi_cntrl->mhi_event, num,
703 					    GFP_KERNEL);
704 	if (!mhi_cntrl->mhi_event)
705 		return -ENOMEM;
706 
707 	/* Populate event ring */
708 	mhi_event = mhi_cntrl->mhi_event;
709 	for (i = 0; i < num; i++) {
710 		event_cfg = &config->event_cfg[i];
711 
712 		mhi_event->er_index = i;
713 		mhi_event->ring.elements = event_cfg->num_elements;
714 		mhi_event->intmod = event_cfg->irq_moderation_ms;
715 		mhi_event->irq = event_cfg->irq;
716 
717 		if (event_cfg->channel != U32_MAX) {
718 			/* This event ring has a dedicated channel */
719 			mhi_event->chan = event_cfg->channel;
720 			if (mhi_event->chan >= mhi_cntrl->max_chan) {
721 				dev_err(dev,
722 					"Event Ring channel not available\n");
723 				goto error_ev_cfg;
724 			}
725 
726 			mhi_event->mhi_chan =
727 				&mhi_cntrl->mhi_chan[mhi_event->chan];
728 		}
729 
730 		/* Priority is fixed to 1 for now */
731 		mhi_event->priority = 1;
732 
733 		mhi_event->db_cfg.brstmode = event_cfg->mode;
734 		if (MHI_INVALID_BRSTMODE(mhi_event->db_cfg.brstmode))
735 			goto error_ev_cfg;
736 
737 		if (mhi_event->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
738 			mhi_event->db_cfg.process_db = mhi_db_brstmode;
739 		else
740 			mhi_event->db_cfg.process_db = mhi_db_brstmode_disable;
741 
742 		mhi_event->data_type = event_cfg->data_type;
743 
744 		switch (mhi_event->data_type) {
745 		case MHI_ER_DATA:
746 			mhi_event->process_event = mhi_process_data_event_ring;
747 			break;
748 		case MHI_ER_CTRL:
749 			mhi_event->process_event = mhi_process_ctrl_ev_ring;
750 			break;
751 		default:
752 			dev_err(dev, "Event Ring type not supported\n");
753 			goto error_ev_cfg;
754 		}
755 
756 		mhi_event->hw_ring = event_cfg->hardware_event;
757 		if (mhi_event->hw_ring)
758 			mhi_cntrl->hw_ev_rings++;
759 		else
760 			mhi_cntrl->sw_ev_rings++;
761 
762 		mhi_event->cl_manage = event_cfg->client_managed;
763 		mhi_event->offload_ev = event_cfg->offload_channel;
764 		mhi_event++;
765 	}
766 
767 	return 0;
768 
769 error_ev_cfg:
770 
771 	kfree(mhi_cntrl->mhi_event);
772 	return -EINVAL;
773 }
774 
775 static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
776 			const struct mhi_controller_config *config)
777 {
778 	const struct mhi_channel_config *ch_cfg;
779 	struct device *dev = mhi_cntrl->cntrl_dev;
780 	int i;
781 	u32 chan;
782 
783 	mhi_cntrl->max_chan = config->max_channels;
784 
785 	/*
786 	 * The allocation of MHI channels can exceed 32KB in some scenarios,
787 	 * so to avoid any memory possible allocation failures, vzalloc is
788 	 * used here
789 	 */
790 	mhi_cntrl->mhi_chan = vcalloc(mhi_cntrl->max_chan,
791 				      sizeof(*mhi_cntrl->mhi_chan));
792 	if (!mhi_cntrl->mhi_chan)
793 		return -ENOMEM;
794 
795 	INIT_LIST_HEAD(&mhi_cntrl->lpm_chans);
796 
797 	/* Populate channel configurations */
798 	for (i = 0; i < config->num_channels; i++) {
799 		struct mhi_chan *mhi_chan;
800 
801 		ch_cfg = &config->ch_cfg[i];
802 
803 		chan = ch_cfg->num;
804 		if (chan >= mhi_cntrl->max_chan) {
805 			dev_err(dev, "Channel %d not available\n", chan);
806 			goto error_chan_cfg;
807 		}
808 
809 		mhi_chan = &mhi_cntrl->mhi_chan[chan];
810 		mhi_chan->name = ch_cfg->name;
811 		mhi_chan->chan = chan;
812 
813 		mhi_chan->tre_ring.elements = ch_cfg->num_elements;
814 		if (!mhi_chan->tre_ring.elements)
815 			goto error_chan_cfg;
816 
817 		/*
818 		 * For some channels, local ring length should be bigger than
819 		 * the transfer ring length due to internal logical channels
820 		 * in device. So host can queue much more buffers than transfer
821 		 * ring length. Example, RSC channels should have a larger local
822 		 * channel length than transfer ring length.
823 		 */
824 		mhi_chan->buf_ring.elements = ch_cfg->local_elements;
825 		if (!mhi_chan->buf_ring.elements)
826 			mhi_chan->buf_ring.elements = mhi_chan->tre_ring.elements;
827 		mhi_chan->er_index = ch_cfg->event_ring;
828 		mhi_chan->dir = ch_cfg->dir;
829 
830 		/*
831 		 * For most channels, chtype is identical to channel directions.
832 		 * So, if it is not defined then assign channel direction to
833 		 * chtype
834 		 */
835 		mhi_chan->type = ch_cfg->type;
836 		if (!mhi_chan->type)
837 			mhi_chan->type = (enum mhi_ch_type)mhi_chan->dir;
838 
839 		mhi_chan->ee_mask = ch_cfg->ee_mask;
840 		mhi_chan->db_cfg.pollcfg = ch_cfg->pollcfg;
841 		mhi_chan->lpm_notify = ch_cfg->lpm_notify;
842 		mhi_chan->offload_ch = ch_cfg->offload_channel;
843 		mhi_chan->db_cfg.reset_req = ch_cfg->doorbell_mode_switch;
844 		mhi_chan->wake_capable = ch_cfg->wake_capable;
845 
846 		/*
847 		 * Bi-directional and direction less channel must be an
848 		 * offload channel
849 		 */
850 		if ((mhi_chan->dir == DMA_BIDIRECTIONAL ||
851 		     mhi_chan->dir == DMA_NONE) && !mhi_chan->offload_ch) {
852 			dev_err(dev, "Invalid channel configuration\n");
853 			goto error_chan_cfg;
854 		}
855 
856 		if (!mhi_chan->offload_ch) {
857 			mhi_chan->db_cfg.brstmode = ch_cfg->doorbell;
858 			if (MHI_INVALID_BRSTMODE(mhi_chan->db_cfg.brstmode)) {
859 				dev_err(dev, "Invalid Door bell mode\n");
860 				goto error_chan_cfg;
861 			}
862 		}
863 
864 		if (mhi_chan->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
865 			mhi_chan->db_cfg.process_db = mhi_db_brstmode;
866 		else
867 			mhi_chan->db_cfg.process_db = mhi_db_brstmode_disable;
868 
869 		mhi_chan->configured = true;
870 
871 		if (mhi_chan->lpm_notify)
872 			list_add_tail(&mhi_chan->node, &mhi_cntrl->lpm_chans);
873 	}
874 
875 	return 0;
876 
877 error_chan_cfg:
878 	vfree(mhi_cntrl->mhi_chan);
879 
880 	return -EINVAL;
881 }
882 
883 static int parse_config(struct mhi_controller *mhi_cntrl,
884 			const struct mhi_controller_config *config)
885 {
886 	int ret;
887 
888 	/* Parse MHI channel configuration */
889 	ret = parse_ch_cfg(mhi_cntrl, config);
890 	if (ret)
891 		return ret;
892 
893 	/* Parse MHI event configuration */
894 	ret = parse_ev_cfg(mhi_cntrl, config);
895 	if (ret)
896 		goto error_ev_cfg;
897 
898 	mhi_cntrl->timeout_ms = config->timeout_ms;
899 	if (!mhi_cntrl->timeout_ms)
900 		mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;
901 
902 	mhi_cntrl->ready_timeout_ms = config->ready_timeout_ms;
903 	mhi_cntrl->bounce_buf = config->use_bounce_buf;
904 	mhi_cntrl->buffer_len = config->buf_len;
905 	if (!mhi_cntrl->buffer_len)
906 		mhi_cntrl->buffer_len = MHI_MAX_MTU;
907 
908 	/* By default, host is allowed to ring DB in both M0 and M2 states */
909 	mhi_cntrl->db_access = MHI_PM_M0 | MHI_PM_M2;
910 	if (config->m2_no_db)
911 		mhi_cntrl->db_access &= ~MHI_PM_M2;
912 
913 	return 0;
914 
915 error_ev_cfg:
916 	vfree(mhi_cntrl->mhi_chan);
917 
918 	return ret;
919 }
920 
921 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
922 			    const struct mhi_controller_config *config)
923 {
924 	struct mhi_event *mhi_event;
925 	struct mhi_chan *mhi_chan;
926 	struct mhi_cmd *mhi_cmd;
927 	struct mhi_device *mhi_dev;
928 	int ret, i;
929 
930 	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
931 	    !mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
932 	    !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
933 	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs ||
934 	    !mhi_cntrl->irq || !mhi_cntrl->reg_len)
935 		return -EINVAL;
936 
937 	ret = parse_config(mhi_cntrl, config);
938 	if (ret)
939 		return -EINVAL;
940 
941 	mhi_cntrl->mhi_cmd = kzalloc_objs(*mhi_cntrl->mhi_cmd, NR_OF_CMD_RINGS,
942 					  GFP_KERNEL);
943 	if (!mhi_cntrl->mhi_cmd) {
944 		ret = -ENOMEM;
945 		goto err_free_event;
946 	}
947 
948 	INIT_LIST_HEAD(&mhi_cntrl->transition_list);
949 	mutex_init(&mhi_cntrl->pm_mutex);
950 	rwlock_init(&mhi_cntrl->pm_lock);
951 	spin_lock_init(&mhi_cntrl->transition_lock);
952 	spin_lock_init(&mhi_cntrl->wlock);
953 	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
954 	init_waitqueue_head(&mhi_cntrl->state_event);
955 
956 	mhi_cntrl->hiprio_wq = alloc_ordered_workqueue("mhi_hiprio_wq", WQ_HIGHPRI);
957 	if (!mhi_cntrl->hiprio_wq) {
958 		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
959 		ret = -ENOMEM;
960 		goto err_free_cmd;
961 	}
962 
963 	mhi_cmd = mhi_cntrl->mhi_cmd;
964 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
965 		spin_lock_init(&mhi_cmd->lock);
966 
967 	mhi_event = mhi_cntrl->mhi_event;
968 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
969 		/* Skip for offload events */
970 		if (mhi_event->offload_ev)
971 			continue;
972 
973 		mhi_event->mhi_cntrl = mhi_cntrl;
974 		spin_lock_init(&mhi_event->lock);
975 		if (mhi_event->data_type == MHI_ER_CTRL)
976 			tasklet_init(&mhi_event->task, mhi_ctrl_ev_task,
977 				     (ulong)mhi_event);
978 		else
979 			tasklet_init(&mhi_event->task, mhi_ev_task,
980 				     (ulong)mhi_event);
981 	}
982 
983 	mhi_chan = mhi_cntrl->mhi_chan;
984 	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
985 		mutex_init(&mhi_chan->mutex);
986 		init_completion(&mhi_chan->completion);
987 		rwlock_init(&mhi_chan->lock);
988 
989 		/* used in setting bei field of TRE */
990 		mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
991 		mhi_chan->intmod = mhi_event->intmod;
992 	}
993 
994 	if (mhi_cntrl->bounce_buf) {
995 		mhi_cntrl->map_single = mhi_map_single_use_bb;
996 		mhi_cntrl->unmap_single = mhi_unmap_single_use_bb;
997 	} else {
998 		mhi_cntrl->map_single = mhi_map_single_no_bb;
999 		mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
1000 	}
1001 
1002 	mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
1003 	if (mhi_cntrl->index < 0) {
1004 		ret = mhi_cntrl->index;
1005 		goto err_destroy_wq;
1006 	}
1007 
1008 	ret = mhi_init_irq_setup(mhi_cntrl);
1009 	if (ret)
1010 		goto err_ida_free;
1011 
1012 	/* Register controller with MHI bus */
1013 	mhi_dev = mhi_alloc_device(mhi_cntrl);
1014 	if (IS_ERR(mhi_dev)) {
1015 		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n");
1016 		ret = PTR_ERR(mhi_dev);
1017 		goto error_setup_irq;
1018 	}
1019 
1020 	mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
1021 	mhi_dev->mhi_cntrl = mhi_cntrl;
1022 	dev_set_name(&mhi_dev->dev, "mhi%d", mhi_cntrl->index);
1023 	mhi_dev->name = dev_name(&mhi_dev->dev);
1024 
1025 	/* Init wakeup source */
1026 	device_init_wakeup(&mhi_dev->dev, true);
1027 
1028 	ret = device_add(&mhi_dev->dev);
1029 	if (ret)
1030 		goto err_release_dev;
1031 
1032 	if (mhi_cntrl->edl_trigger) {
1033 		ret = sysfs_create_file(&mhi_dev->dev.kobj, &dev_attr_trigger_edl.attr);
1034 		if (ret)
1035 			goto err_release_dev;
1036 	}
1037 
1038 	mhi_cntrl->mhi_dev = mhi_dev;
1039 
1040 	mhi_create_debugfs(mhi_cntrl);
1041 
1042 	return 0;
1043 
1044 err_release_dev:
1045 	put_device(&mhi_dev->dev);
1046 error_setup_irq:
1047 	mhi_deinit_free_irq(mhi_cntrl);
1048 err_ida_free:
1049 	ida_free(&mhi_controller_ida, mhi_cntrl->index);
1050 err_destroy_wq:
1051 	destroy_workqueue(mhi_cntrl->hiprio_wq);
1052 err_free_cmd:
1053 	kfree(mhi_cntrl->mhi_cmd);
1054 err_free_event:
1055 	kfree(mhi_cntrl->mhi_event);
1056 	vfree(mhi_cntrl->mhi_chan);
1057 
1058 	return ret;
1059 }
1060 EXPORT_SYMBOL_GPL(mhi_register_controller);
1061 
1062 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
1063 {
1064 	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
1065 	struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
1066 	unsigned int i;
1067 
1068 	mhi_deinit_free_irq(mhi_cntrl);
1069 	mhi_destroy_debugfs(mhi_cntrl);
1070 
1071 	if (mhi_cntrl->edl_trigger)
1072 		sysfs_remove_file(&mhi_dev->dev.kobj, &dev_attr_trigger_edl.attr);
1073 
1074 	destroy_workqueue(mhi_cntrl->hiprio_wq);
1075 	kfree(mhi_cntrl->mhi_cmd);
1076 	kfree(mhi_cntrl->mhi_event);
1077 
1078 	/* Drop the references to MHI devices created for channels */
1079 	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
1080 		if (!mhi_chan->mhi_dev)
1081 			continue;
1082 
1083 		put_device(&mhi_chan->mhi_dev->dev);
1084 	}
1085 	vfree(mhi_cntrl->mhi_chan);
1086 
1087 	device_del(&mhi_dev->dev);
1088 	put_device(&mhi_dev->dev);
1089 
1090 	ida_free(&mhi_controller_ida, mhi_cntrl->index);
1091 }
1092 EXPORT_SYMBOL_GPL(mhi_unregister_controller);
1093 
1094 struct mhi_controller *mhi_alloc_controller(void)
1095 {
1096 	struct mhi_controller *mhi_cntrl;
1097 
1098 	mhi_cntrl = kzalloc_obj(*mhi_cntrl);
1099 
1100 	return mhi_cntrl;
1101 }
1102 EXPORT_SYMBOL_GPL(mhi_alloc_controller);
1103 
1104 void mhi_free_controller(struct mhi_controller *mhi_cntrl)
1105 {
1106 	kfree(mhi_cntrl);
1107 }
1108 EXPORT_SYMBOL_GPL(mhi_free_controller);
1109 
1110 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
1111 {
1112 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
1113 	u32 bhi_off, bhie_off;
1114 	int ret;
1115 
1116 	mutex_lock(&mhi_cntrl->pm_mutex);
1117 
1118 	ret = mhi_init_dev_ctxt(mhi_cntrl);
1119 	if (ret)
1120 		goto error_dev_ctxt;
1121 
1122 	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIOFF, &bhi_off);
1123 	if (ret) {
1124 		dev_err(dev, "Error getting BHI offset\n");
1125 		goto error_reg_offset;
1126 	}
1127 
1128 	if (bhi_off >= mhi_cntrl->reg_len) {
1129 		dev_err(dev, "BHI offset: 0x%x is out of range: 0x%zx\n",
1130 			bhi_off, mhi_cntrl->reg_len);
1131 		ret = -ERANGE;
1132 		goto error_reg_offset;
1133 	}
1134 	mhi_cntrl->bhi = mhi_cntrl->regs + bhi_off;
1135 
1136 	if (mhi_cntrl->fbc_download || mhi_cntrl->rddm_size || mhi_cntrl->seg_len) {
1137 		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF,
1138 				   &bhie_off);
1139 		if (ret) {
1140 			dev_err(dev, "Error getting BHIE offset\n");
1141 			goto error_reg_offset;
1142 		}
1143 
1144 		if (bhie_off >= mhi_cntrl->reg_len) {
1145 			dev_err(dev,
1146 				"BHIe offset: 0x%x is out of range: 0x%zx\n",
1147 				bhie_off, mhi_cntrl->reg_len);
1148 			ret = -ERANGE;
1149 			goto error_reg_offset;
1150 		}
1151 		mhi_cntrl->bhie = mhi_cntrl->regs + bhie_off;
1152 	}
1153 
1154 	if (mhi_cntrl->rddm_size) {
1155 		/*
1156 		 * This controller supports RDDM, so we need to manually clear
1157 		 * BHIE RX registers since POR values are undefined.
1158 		 */
1159 		memset_io(mhi_cntrl->bhie + BHIE_RXVECADDR_LOW_OFFS,
1160 			  0, BHIE_RXVECSTATUS_OFFS - BHIE_RXVECADDR_LOW_OFFS +
1161 			  4);
1162 		/*
1163 		 * Allocate RDDM table for debugging purpose if specified
1164 		 */
1165 		mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
1166 				     mhi_cntrl->rddm_size);
1167 		if (mhi_cntrl->rddm_image) {
1168 			ret = mhi_rddm_prepare(mhi_cntrl,
1169 					       mhi_cntrl->rddm_image);
1170 			if (ret) {
1171 				mhi_free_bhie_table(mhi_cntrl,
1172 						    mhi_cntrl->rddm_image);
1173 				goto error_reg_offset;
1174 			}
1175 		}
1176 	}
1177 
1178 	mutex_unlock(&mhi_cntrl->pm_mutex);
1179 
1180 	return 0;
1181 
1182 error_reg_offset:
1183 	mhi_deinit_dev_ctxt(mhi_cntrl);
1184 
1185 error_dev_ctxt:
1186 	mutex_unlock(&mhi_cntrl->pm_mutex);
1187 
1188 	return ret;
1189 }
1190 EXPORT_SYMBOL_GPL(mhi_prepare_for_power_up);
1191 
1192 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
1193 {
1194 	if (mhi_cntrl->fbc_image) {
1195 		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
1196 		mhi_cntrl->fbc_image = NULL;
1197 	}
1198 
1199 	if (mhi_cntrl->rddm_image) {
1200 		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
1201 		mhi_cntrl->rddm_image = NULL;
1202 	}
1203 
1204 	mhi_cntrl->bhi = NULL;
1205 	mhi_cntrl->bhie = NULL;
1206 
1207 	mhi_deinit_dev_ctxt(mhi_cntrl);
1208 }
1209 EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
1210 
1211 static void mhi_release_device(struct device *dev)
1212 {
1213 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1214 
1215 	/*
1216 	 * We need to set the mhi_chan->mhi_dev to NULL here since the MHI
1217 	 * devices for the channels will only get created if the mhi_dev
1218 	 * associated with it is NULL. This scenario will happen during the
1219 	 * controller suspend and resume.
1220 	 */
1221 	if (mhi_dev->ul_chan)
1222 		mhi_dev->ul_chan->mhi_dev = NULL;
1223 
1224 	if (mhi_dev->dl_chan)
1225 		mhi_dev->dl_chan->mhi_dev = NULL;
1226 
1227 	kfree(mhi_dev);
1228 }
1229 
1230 struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
1231 {
1232 	struct mhi_device *mhi_dev;
1233 	struct device *dev;
1234 
1235 	mhi_dev = kzalloc_obj(*mhi_dev);
1236 	if (!mhi_dev)
1237 		return ERR_PTR(-ENOMEM);
1238 
1239 	dev = &mhi_dev->dev;
1240 	device_initialize(dev);
1241 	dev->bus = &mhi_bus_type;
1242 	dev->release = mhi_release_device;
1243 
1244 	if (mhi_cntrl->mhi_dev) {
1245 		/* for MHI client devices, parent is the MHI controller device */
1246 		dev->parent = &mhi_cntrl->mhi_dev->dev;
1247 	} else {
1248 		/* for MHI controller device, parent is the bus device (e.g. pci device) */
1249 		dev->parent = mhi_cntrl->cntrl_dev;
1250 	}
1251 
1252 	mhi_dev->mhi_cntrl = mhi_cntrl;
1253 	mhi_dev->dev_wake = 0;
1254 
1255 	return mhi_dev;
1256 }
1257 
1258 static int mhi_probe(struct device *dev)
1259 {
1260 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1261 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1262 	struct device_driver *drv = dev->driver;
1263 	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1264 	struct mhi_event *mhi_event;
1265 	struct mhi_chan *ul_chan = mhi_dev->ul_chan;
1266 	struct mhi_chan *dl_chan = mhi_dev->dl_chan;
1267 	int ret;
1268 
1269 	/* Bring device out of LPM */
1270 	ret = mhi_device_get_sync(mhi_dev);
1271 	if (ret)
1272 		return ret;
1273 
1274 	ret = -EINVAL;
1275 
1276 	if (ul_chan) {
1277 		/*
1278 		 * If channel supports LPM notifications then status_cb should
1279 		 * be provided
1280 		 */
1281 		if (ul_chan->lpm_notify && !mhi_drv->status_cb)
1282 			goto exit_probe;
1283 
1284 		/* For non-offload channels then xfer_cb should be provided */
1285 		if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb)
1286 			goto exit_probe;
1287 
1288 		ul_chan->xfer_cb = mhi_drv->ul_xfer_cb;
1289 	}
1290 
1291 	ret = -EINVAL;
1292 	if (dl_chan) {
1293 		/*
1294 		 * If channel supports LPM notifications then status_cb should
1295 		 * be provided
1296 		 */
1297 		if (dl_chan->lpm_notify && !mhi_drv->status_cb)
1298 			goto exit_probe;
1299 
1300 		/* For non-offload channels then xfer_cb should be provided */
1301 		if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb)
1302 			goto exit_probe;
1303 
1304 		mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index];
1305 
1306 		/*
1307 		 * If the channel event ring is managed by client, then
1308 		 * status_cb must be provided so that the framework can
1309 		 * notify pending data
1310 		 */
1311 		if (mhi_event->cl_manage && !mhi_drv->status_cb)
1312 			goto exit_probe;
1313 
1314 		dl_chan->xfer_cb = mhi_drv->dl_xfer_cb;
1315 	}
1316 
1317 	/* Call the user provided probe function */
1318 	ret = mhi_drv->probe(mhi_dev, mhi_dev->id);
1319 	if (ret)
1320 		goto exit_probe;
1321 
1322 	mhi_device_put(mhi_dev);
1323 
1324 	return ret;
1325 
1326 exit_probe:
1327 	mhi_unprepare_from_transfer(mhi_dev);
1328 
1329 	mhi_device_put(mhi_dev);
1330 
1331 	return ret;
1332 }
1333 
1334 static void mhi_remove(struct device *dev)
1335 {
1336 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1337 	struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver);
1338 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1339 	struct mhi_chan *mhi_chan;
1340 	enum mhi_ch_state ch_state[] = {
1341 		MHI_CH_STATE_DISABLED,
1342 		MHI_CH_STATE_DISABLED
1343 	};
1344 	int dir;
1345 
1346 	/* Skip if it is a controller device */
1347 	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1348 		return;
1349 
1350 	/* Reset both channels */
1351 	for (dir = 0; dir < 2; dir++) {
1352 		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1353 
1354 		if (!mhi_chan)
1355 			continue;
1356 
1357 		/* Wake all threads waiting for completion */
1358 		write_lock_irq(&mhi_chan->lock);
1359 		mhi_chan->ccs = MHI_EV_CC_INVALID;
1360 		complete_all(&mhi_chan->completion);
1361 		write_unlock_irq(&mhi_chan->lock);
1362 
1363 		/* Set the channel state to disabled */
1364 		mutex_lock(&mhi_chan->mutex);
1365 		write_lock_irq(&mhi_chan->lock);
1366 		ch_state[dir] = mhi_chan->ch_state;
1367 		mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED;
1368 		write_unlock_irq(&mhi_chan->lock);
1369 
1370 		/* Reset the non-offload channel */
1371 		if (!mhi_chan->offload_ch)
1372 			mhi_reset_chan(mhi_cntrl, mhi_chan);
1373 
1374 		mutex_unlock(&mhi_chan->mutex);
1375 	}
1376 
1377 	mhi_drv->remove(mhi_dev);
1378 
1379 	/* De-init channel if it was enabled */
1380 	for (dir = 0; dir < 2; dir++) {
1381 		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1382 
1383 		if (!mhi_chan)
1384 			continue;
1385 
1386 		mutex_lock(&mhi_chan->mutex);
1387 
1388 		if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
1389 		     ch_state[dir] == MHI_CH_STATE_STOP) &&
1390 		    !mhi_chan->offload_ch)
1391 			mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
1392 
1393 		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
1394 
1395 		mutex_unlock(&mhi_chan->mutex);
1396 	}
1397 
1398 	while (mhi_dev->dev_wake)
1399 		mhi_device_put(mhi_dev);
1400 }
1401 
1402 int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner)
1403 {
1404 	struct device_driver *driver = &mhi_drv->driver;
1405 
1406 	if (!mhi_drv->probe || !mhi_drv->remove)
1407 		return -EINVAL;
1408 
1409 	driver->bus = &mhi_bus_type;
1410 	driver->owner = owner;
1411 
1412 	return driver_register(driver);
1413 }
1414 EXPORT_SYMBOL_GPL(__mhi_driver_register);
1415 
1416 void mhi_driver_unregister(struct mhi_driver *mhi_drv)
1417 {
1418 	driver_unregister(&mhi_drv->driver);
1419 }
1420 EXPORT_SYMBOL_GPL(mhi_driver_unregister);
1421 
1422 static int mhi_uevent(const struct device *dev, struct kobj_uevent_env *env)
1423 {
1424 	const struct mhi_device *mhi_dev = to_mhi_device(dev);
1425 
1426 	return add_uevent_var(env, "MODALIAS=" MHI_DEVICE_MODALIAS_FMT,
1427 					mhi_dev->name);
1428 }
1429 
1430 static int mhi_match(struct device *dev, const struct device_driver *drv)
1431 {
1432 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1433 	const struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1434 	const struct mhi_device_id *id;
1435 
1436 	/*
1437 	 * If the device is a controller type then there is no client driver
1438 	 * associated with it
1439 	 */
1440 	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1441 		return 0;
1442 
1443 	for (id = mhi_drv->id_table; id->chan[0]; id++)
1444 		if (!strcmp(mhi_dev->name, id->chan)) {
1445 			mhi_dev->id = id;
1446 			return 1;
1447 		}
1448 
1449 	return 0;
1450 };
1451 
1452 const struct bus_type mhi_bus_type = {
1453 	.name = "mhi",
1454 	.dev_name = "mhi",
1455 	.match = mhi_match,
1456 	.uevent = mhi_uevent,
1457 	.probe = mhi_probe,
1458 	.remove = mhi_remove,
1459 	.dev_groups = mhi_dev_groups,
1460 };
1461 
1462 static int __init mhi_init(void)
1463 {
1464 	mhi_debugfs_init();
1465 	return bus_register(&mhi_bus_type);
1466 }
1467 
1468 static void __exit mhi_exit(void)
1469 {
1470 	mhi_debugfs_exit();
1471 	bus_unregister(&mhi_bus_type);
1472 }
1473 
1474 postcore_initcall(mhi_init);
1475 module_exit(mhi_exit);
1476 
1477 MODULE_LICENSE("GPL v2");
1478 MODULE_DESCRIPTION("Modem Host Interface");
1479