xref: /openbmc/linux/drivers/bus/mhi/host/init.c (revision e80a48ba)
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 static DEFINE_IDA(mhi_controller_ida);
24 
25 const char * const mhi_ee_str[MHI_EE_MAX] = {
26 	[MHI_EE_PBL] = "PRIMARY BOOTLOADER",
27 	[MHI_EE_SBL] = "SECONDARY BOOTLOADER",
28 	[MHI_EE_AMSS] = "MISSION MODE",
29 	[MHI_EE_RDDM] = "RAMDUMP DOWNLOAD MODE",
30 	[MHI_EE_WFW] = "WLAN FIRMWARE",
31 	[MHI_EE_PTHRU] = "PASS THROUGH",
32 	[MHI_EE_EDL] = "EMERGENCY DOWNLOAD",
33 	[MHI_EE_FP] = "FLASH PROGRAMMER",
34 	[MHI_EE_DISABLE_TRANSITION] = "DISABLE",
35 	[MHI_EE_NOT_SUPPORTED] = "NOT SUPPORTED",
36 };
37 
38 const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
39 	[DEV_ST_TRANSITION_PBL] = "PBL",
40 	[DEV_ST_TRANSITION_READY] = "READY",
41 	[DEV_ST_TRANSITION_SBL] = "SBL",
42 	[DEV_ST_TRANSITION_MISSION_MODE] = "MISSION MODE",
43 	[DEV_ST_TRANSITION_FP] = "FLASH PROGRAMMER",
44 	[DEV_ST_TRANSITION_SYS_ERR] = "SYS ERROR",
45 	[DEV_ST_TRANSITION_DISABLE] = "DISABLE",
46 };
47 
48 const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX] = {
49 	[MHI_CH_STATE_TYPE_RESET] = "RESET",
50 	[MHI_CH_STATE_TYPE_STOP] = "STOP",
51 	[MHI_CH_STATE_TYPE_START] = "START",
52 };
53 
54 static const char * const mhi_pm_state_str[] = {
55 	[MHI_PM_STATE_DISABLE] = "DISABLE",
56 	[MHI_PM_STATE_POR] = "POWER ON RESET",
57 	[MHI_PM_STATE_M0] = "M0",
58 	[MHI_PM_STATE_M2] = "M2",
59 	[MHI_PM_STATE_M3_ENTER] = "M?->M3",
60 	[MHI_PM_STATE_M3] = "M3",
61 	[MHI_PM_STATE_M3_EXIT] = "M3->M0",
62 	[MHI_PM_STATE_FW_DL_ERR] = "Firmware Download Error",
63 	[MHI_PM_STATE_SYS_ERR_DETECT] = "SYS ERROR Detect",
64 	[MHI_PM_STATE_SYS_ERR_PROCESS] = "SYS ERROR Process",
65 	[MHI_PM_STATE_SHUTDOWN_PROCESS] = "SHUTDOWN Process",
66 	[MHI_PM_STATE_LD_ERR_FATAL_DETECT] = "Linkdown or Error Fatal Detect",
67 };
68 
69 const char *to_mhi_pm_state_str(u32 state)
70 {
71 	int index;
72 
73 	if (state)
74 		index = __fls(state);
75 
76 	if (!state || index >= ARRAY_SIZE(mhi_pm_state_str))
77 		return "Invalid State";
78 
79 	return mhi_pm_state_str[index];
80 }
81 
82 static ssize_t serial_number_show(struct device *dev,
83 				  struct device_attribute *attr,
84 				  char *buf)
85 {
86 	struct mhi_device *mhi_dev = to_mhi_device(dev);
87 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
88 
89 	return sysfs_emit(buf, "Serial Number: %u\n",
90 			mhi_cntrl->serial_number);
91 }
92 static DEVICE_ATTR_RO(serial_number);
93 
94 static ssize_t oem_pk_hash_show(struct device *dev,
95 				struct device_attribute *attr,
96 				char *buf)
97 {
98 	struct mhi_device *mhi_dev = to_mhi_device(dev);
99 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
100 	int i, cnt = 0;
101 
102 	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++)
103 		cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n",
104 				i, mhi_cntrl->oem_pk_hash[i]);
105 
106 	return cnt;
107 }
108 static DEVICE_ATTR_RO(oem_pk_hash);
109 
110 static ssize_t soc_reset_store(struct device *dev,
111 			       struct device_attribute *attr,
112 			       const char *buf,
113 			       size_t count)
114 {
115 	struct mhi_device *mhi_dev = to_mhi_device(dev);
116 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
117 
118 	mhi_soc_reset(mhi_cntrl);
119 	return count;
120 }
121 static DEVICE_ATTR_WO(soc_reset);
122 
123 static struct attribute *mhi_dev_attrs[] = {
124 	&dev_attr_serial_number.attr,
125 	&dev_attr_oem_pk_hash.attr,
126 	&dev_attr_soc_reset.attr,
127 	NULL,
128 };
129 ATTRIBUTE_GROUPS(mhi_dev);
130 
131 /* MHI protocol requires the transfer ring to be aligned with ring length */
132 static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
133 				  struct mhi_ring *ring,
134 				  u64 len)
135 {
136 	ring->alloc_size = len + (len - 1);
137 	ring->pre_aligned = dma_alloc_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
138 					       &ring->dma_handle, GFP_KERNEL);
139 	if (!ring->pre_aligned)
140 		return -ENOMEM;
141 
142 	ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);
143 	ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);
144 
145 	return 0;
146 }
147 
148 void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)
149 {
150 	int i;
151 	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
152 
153 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
154 		if (mhi_event->offload_ev)
155 			continue;
156 
157 		free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
158 	}
159 
160 	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
161 }
162 
163 int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
164 {
165 	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
166 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
167 	unsigned long irq_flags = IRQF_SHARED | IRQF_NO_SUSPEND;
168 	int i, ret;
169 
170 	/* if controller driver has set irq_flags, use it */
171 	if (mhi_cntrl->irq_flags)
172 		irq_flags = mhi_cntrl->irq_flags;
173 
174 	/* Setup BHI_INTVEC IRQ */
175 	ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handler,
176 				   mhi_intvec_threaded_handler,
177 				   irq_flags,
178 				   "bhi", mhi_cntrl);
179 	if (ret)
180 		return ret;
181 	/*
182 	 * IRQs should be enabled during mhi_async_power_up(), so disable them explicitly here.
183 	 * Due to the use of IRQF_SHARED flag as default while requesting IRQs, we assume that
184 	 * IRQ_NOAUTOEN is not applicable.
185 	 */
186 	disable_irq(mhi_cntrl->irq[0]);
187 
188 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
189 		if (mhi_event->offload_ev)
190 			continue;
191 
192 		if (mhi_event->irq >= mhi_cntrl->nr_irqs) {
193 			dev_err(dev, "irq %d not available for event ring\n",
194 				mhi_event->irq);
195 			ret = -EINVAL;
196 			goto error_request;
197 		}
198 
199 		ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
200 				  mhi_irq_handler,
201 				  irq_flags,
202 				  "mhi", mhi_event);
203 		if (ret) {
204 			dev_err(dev, "Error requesting irq:%d for ev:%d\n",
205 				mhi_cntrl->irq[mhi_event->irq], i);
206 			goto error_request;
207 		}
208 
209 		disable_irq(mhi_cntrl->irq[mhi_event->irq]);
210 	}
211 
212 	return 0;
213 
214 error_request:
215 	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
216 		if (mhi_event->offload_ev)
217 			continue;
218 
219 		free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
220 	}
221 	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
222 
223 	return ret;
224 }
225 
226 void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl)
227 {
228 	int i;
229 	struct mhi_ctxt *mhi_ctxt = mhi_cntrl->mhi_ctxt;
230 	struct mhi_cmd *mhi_cmd;
231 	struct mhi_event *mhi_event;
232 	struct mhi_ring *ring;
233 
234 	mhi_cmd = mhi_cntrl->mhi_cmd;
235 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++) {
236 		ring = &mhi_cmd->ring;
237 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
238 				  ring->pre_aligned, ring->dma_handle);
239 		ring->base = NULL;
240 		ring->iommu_base = 0;
241 	}
242 
243 	dma_free_coherent(mhi_cntrl->cntrl_dev,
244 			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
245 			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
246 
247 	mhi_event = mhi_cntrl->mhi_event;
248 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
249 		if (mhi_event->offload_ev)
250 			continue;
251 
252 		ring = &mhi_event->ring;
253 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
254 				  ring->pre_aligned, ring->dma_handle);
255 		ring->base = NULL;
256 		ring->iommu_base = 0;
257 	}
258 
259 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->er_ctxt) *
260 			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
261 			  mhi_ctxt->er_ctxt_addr);
262 
263 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->chan_ctxt) *
264 			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
265 			  mhi_ctxt->chan_ctxt_addr);
266 
267 	kfree(mhi_ctxt);
268 	mhi_cntrl->mhi_ctxt = NULL;
269 }
270 
271 int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
272 {
273 	struct mhi_ctxt *mhi_ctxt;
274 	struct mhi_chan_ctxt *chan_ctxt;
275 	struct mhi_event_ctxt *er_ctxt;
276 	struct mhi_cmd_ctxt *cmd_ctxt;
277 	struct mhi_chan *mhi_chan;
278 	struct mhi_event *mhi_event;
279 	struct mhi_cmd *mhi_cmd;
280 	u32 tmp;
281 	int ret = -ENOMEM, i;
282 
283 	atomic_set(&mhi_cntrl->dev_wake, 0);
284 	atomic_set(&mhi_cntrl->pending_pkts, 0);
285 
286 	mhi_ctxt = kzalloc(sizeof(*mhi_ctxt), GFP_KERNEL);
287 	if (!mhi_ctxt)
288 		return -ENOMEM;
289 
290 	/* Setup channel ctxt */
291 	mhi_ctxt->chan_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
292 						 sizeof(*mhi_ctxt->chan_ctxt) *
293 						 mhi_cntrl->max_chan,
294 						 &mhi_ctxt->chan_ctxt_addr,
295 						 GFP_KERNEL);
296 	if (!mhi_ctxt->chan_ctxt)
297 		goto error_alloc_chan_ctxt;
298 
299 	mhi_chan = mhi_cntrl->mhi_chan;
300 	chan_ctxt = mhi_ctxt->chan_ctxt;
301 	for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
302 		/* Skip if it is an offload channel */
303 		if (mhi_chan->offload_ch)
304 			continue;
305 
306 		tmp = le32_to_cpu(chan_ctxt->chcfg);
307 		tmp &= ~CHAN_CTX_CHSTATE_MASK;
308 		tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
309 		tmp &= ~CHAN_CTX_BRSTMODE_MASK;
310 		tmp |= FIELD_PREP(CHAN_CTX_BRSTMODE_MASK, mhi_chan->db_cfg.brstmode);
311 		tmp &= ~CHAN_CTX_POLLCFG_MASK;
312 		tmp |= FIELD_PREP(CHAN_CTX_POLLCFG_MASK, mhi_chan->db_cfg.pollcfg);
313 		chan_ctxt->chcfg = cpu_to_le32(tmp);
314 
315 		chan_ctxt->chtype = cpu_to_le32(mhi_chan->type);
316 		chan_ctxt->erindex = cpu_to_le32(mhi_chan->er_index);
317 
318 		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
319 		mhi_chan->tre_ring.db_addr = (void __iomem *)&chan_ctxt->wp;
320 	}
321 
322 	/* Setup event context */
323 	mhi_ctxt->er_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
324 					       sizeof(*mhi_ctxt->er_ctxt) *
325 					       mhi_cntrl->total_ev_rings,
326 					       &mhi_ctxt->er_ctxt_addr,
327 					       GFP_KERNEL);
328 	if (!mhi_ctxt->er_ctxt)
329 		goto error_alloc_er_ctxt;
330 
331 	er_ctxt = mhi_ctxt->er_ctxt;
332 	mhi_event = mhi_cntrl->mhi_event;
333 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
334 		     mhi_event++) {
335 		struct mhi_ring *ring = &mhi_event->ring;
336 
337 		/* Skip if it is an offload event */
338 		if (mhi_event->offload_ev)
339 			continue;
340 
341 		tmp = le32_to_cpu(er_ctxt->intmod);
342 		tmp &= ~EV_CTX_INTMODC_MASK;
343 		tmp &= ~EV_CTX_INTMODT_MASK;
344 		tmp |= FIELD_PREP(EV_CTX_INTMODT_MASK, mhi_event->intmod);
345 		er_ctxt->intmod = cpu_to_le32(tmp);
346 
347 		er_ctxt->ertype = cpu_to_le32(MHI_ER_TYPE_VALID);
348 		er_ctxt->msivec = cpu_to_le32(mhi_event->irq);
349 		mhi_event->db_cfg.db_mode = true;
350 
351 		ring->el_size = sizeof(struct mhi_ring_element);
352 		ring->len = ring->el_size * ring->elements;
353 		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
354 		if (ret)
355 			goto error_alloc_er;
356 
357 		/*
358 		 * If the read pointer equals to the write pointer, then the
359 		 * ring is empty
360 		 */
361 		ring->rp = ring->wp = ring->base;
362 		er_ctxt->rbase = cpu_to_le64(ring->iommu_base);
363 		er_ctxt->rp = er_ctxt->wp = er_ctxt->rbase;
364 		er_ctxt->rlen = cpu_to_le64(ring->len);
365 		ring->ctxt_wp = &er_ctxt->wp;
366 	}
367 
368 	/* Setup cmd context */
369 	ret = -ENOMEM;
370 	mhi_ctxt->cmd_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
371 						sizeof(*mhi_ctxt->cmd_ctxt) *
372 						NR_OF_CMD_RINGS,
373 						&mhi_ctxt->cmd_ctxt_addr,
374 						GFP_KERNEL);
375 	if (!mhi_ctxt->cmd_ctxt)
376 		goto error_alloc_er;
377 
378 	mhi_cmd = mhi_cntrl->mhi_cmd;
379 	cmd_ctxt = mhi_ctxt->cmd_ctxt;
380 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
381 		struct mhi_ring *ring = &mhi_cmd->ring;
382 
383 		ring->el_size = sizeof(struct mhi_ring_element);
384 		ring->elements = CMD_EL_PER_RING;
385 		ring->len = ring->el_size * ring->elements;
386 		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
387 		if (ret)
388 			goto error_alloc_cmd;
389 
390 		ring->rp = ring->wp = ring->base;
391 		cmd_ctxt->rbase = cpu_to_le64(ring->iommu_base);
392 		cmd_ctxt->rp = cmd_ctxt->wp = cmd_ctxt->rbase;
393 		cmd_ctxt->rlen = cpu_to_le64(ring->len);
394 		ring->ctxt_wp = &cmd_ctxt->wp;
395 	}
396 
397 	mhi_cntrl->mhi_ctxt = mhi_ctxt;
398 
399 	return 0;
400 
401 error_alloc_cmd:
402 	for (--i, --mhi_cmd; i >= 0; i--, mhi_cmd--) {
403 		struct mhi_ring *ring = &mhi_cmd->ring;
404 
405 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
406 				  ring->pre_aligned, ring->dma_handle);
407 	}
408 	dma_free_coherent(mhi_cntrl->cntrl_dev,
409 			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
410 			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
411 	i = mhi_cntrl->total_ev_rings;
412 	mhi_event = mhi_cntrl->mhi_event + i;
413 
414 error_alloc_er:
415 	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
416 		struct mhi_ring *ring = &mhi_event->ring;
417 
418 		if (mhi_event->offload_ev)
419 			continue;
420 
421 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
422 				  ring->pre_aligned, ring->dma_handle);
423 	}
424 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->er_ctxt) *
425 			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
426 			  mhi_ctxt->er_ctxt_addr);
427 
428 error_alloc_er_ctxt:
429 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->chan_ctxt) *
430 			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
431 			  mhi_ctxt->chan_ctxt_addr);
432 
433 error_alloc_chan_ctxt:
434 	kfree(mhi_ctxt);
435 
436 	return ret;
437 }
438 
439 int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
440 {
441 	u32 val;
442 	int i, ret;
443 	struct mhi_chan *mhi_chan;
444 	struct mhi_event *mhi_event;
445 	void __iomem *base = mhi_cntrl->regs;
446 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
447 	struct {
448 		u32 offset;
449 		u32 val;
450 	} reg_info[] = {
451 		{
452 			CCABAP_HIGHER,
453 			upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
454 		},
455 		{
456 			CCABAP_LOWER,
457 			lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
458 		},
459 		{
460 			ECABAP_HIGHER,
461 			upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
462 		},
463 		{
464 			ECABAP_LOWER,
465 			lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
466 		},
467 		{
468 			CRCBAP_HIGHER,
469 			upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
470 		},
471 		{
472 			CRCBAP_LOWER,
473 			lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
474 		},
475 		{
476 			MHICTRLBASE_HIGHER,
477 			upper_32_bits(mhi_cntrl->iova_start),
478 		},
479 		{
480 			MHICTRLBASE_LOWER,
481 			lower_32_bits(mhi_cntrl->iova_start),
482 		},
483 		{
484 			MHIDATABASE_HIGHER,
485 			upper_32_bits(mhi_cntrl->iova_start),
486 		},
487 		{
488 			MHIDATABASE_LOWER,
489 			lower_32_bits(mhi_cntrl->iova_start),
490 		},
491 		{
492 			MHICTRLLIMIT_HIGHER,
493 			upper_32_bits(mhi_cntrl->iova_stop),
494 		},
495 		{
496 			MHICTRLLIMIT_LOWER,
497 			lower_32_bits(mhi_cntrl->iova_stop),
498 		},
499 		{
500 			MHIDATALIMIT_HIGHER,
501 			upper_32_bits(mhi_cntrl->iova_stop),
502 		},
503 		{
504 			MHIDATALIMIT_LOWER,
505 			lower_32_bits(mhi_cntrl->iova_stop),
506 		},
507 		{0, 0}
508 	};
509 
510 	dev_dbg(dev, "Initializing MHI registers\n");
511 
512 	/* Read channel db offset */
513 	ret = mhi_read_reg(mhi_cntrl, base, CHDBOFF, &val);
514 	if (ret) {
515 		dev_err(dev, "Unable to read CHDBOFF register\n");
516 		return -EIO;
517 	}
518 
519 	/* Setup wake db */
520 	mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
521 	mhi_cntrl->wake_set = false;
522 
523 	/* Setup channel db address for each channel in tre_ring */
524 	mhi_chan = mhi_cntrl->mhi_chan;
525 	for (i = 0; i < mhi_cntrl->max_chan; i++, val += 8, mhi_chan++)
526 		mhi_chan->tre_ring.db_addr = base + val;
527 
528 	/* Read event ring db offset */
529 	ret = mhi_read_reg(mhi_cntrl, base, ERDBOFF, &val);
530 	if (ret) {
531 		dev_err(dev, "Unable to read ERDBOFF register\n");
532 		return -EIO;
533 	}
534 
535 	/* Setup event db address for each ev_ring */
536 	mhi_event = mhi_cntrl->mhi_event;
537 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
538 		if (mhi_event->offload_ev)
539 			continue;
540 
541 		mhi_event->ring.db_addr = base + val;
542 	}
543 
544 	/* Setup DB register for primary CMD rings */
545 	mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER;
546 
547 	/* Write to MMIO registers */
548 	for (i = 0; reg_info[i].offset; i++)
549 		mhi_write_reg(mhi_cntrl, base, reg_info[i].offset,
550 			      reg_info[i].val);
551 
552 	ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NER_MASK,
553 				  mhi_cntrl->total_ev_rings);
554 	if (ret) {
555 		dev_err(dev, "Unable to write MHICFG register\n");
556 		return ret;
557 	}
558 
559 	ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NHWER_MASK,
560 				  mhi_cntrl->hw_ev_rings);
561 	if (ret) {
562 		dev_err(dev, "Unable to write MHICFG register\n");
563 		return ret;
564 	}
565 
566 	return 0;
567 }
568 
569 void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
570 			  struct mhi_chan *mhi_chan)
571 {
572 	struct mhi_ring *buf_ring;
573 	struct mhi_ring *tre_ring;
574 	struct mhi_chan_ctxt *chan_ctxt;
575 	u32 tmp;
576 
577 	buf_ring = &mhi_chan->buf_ring;
578 	tre_ring = &mhi_chan->tre_ring;
579 	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
580 
581 	if (!chan_ctxt->rbase) /* Already uninitialized */
582 		return;
583 
584 	dma_free_coherent(mhi_cntrl->cntrl_dev, tre_ring->alloc_size,
585 			  tre_ring->pre_aligned, tre_ring->dma_handle);
586 	vfree(buf_ring->base);
587 
588 	buf_ring->base = tre_ring->base = NULL;
589 	tre_ring->ctxt_wp = NULL;
590 	chan_ctxt->rbase = 0;
591 	chan_ctxt->rlen = 0;
592 	chan_ctxt->rp = 0;
593 	chan_ctxt->wp = 0;
594 
595 	tmp = le32_to_cpu(chan_ctxt->chcfg);
596 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
597 	tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
598 	chan_ctxt->chcfg = cpu_to_le32(tmp);
599 
600 	/* Update to all cores */
601 	smp_wmb();
602 }
603 
604 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
605 		       struct mhi_chan *mhi_chan)
606 {
607 	struct mhi_ring *buf_ring;
608 	struct mhi_ring *tre_ring;
609 	struct mhi_chan_ctxt *chan_ctxt;
610 	u32 tmp;
611 	int ret;
612 
613 	buf_ring = &mhi_chan->buf_ring;
614 	tre_ring = &mhi_chan->tre_ring;
615 	tre_ring->el_size = sizeof(struct mhi_ring_element);
616 	tre_ring->len = tre_ring->el_size * tre_ring->elements;
617 	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
618 	ret = mhi_alloc_aligned_ring(mhi_cntrl, tre_ring, tre_ring->len);
619 	if (ret)
620 		return -ENOMEM;
621 
622 	buf_ring->el_size = sizeof(struct mhi_buf_info);
623 	buf_ring->len = buf_ring->el_size * buf_ring->elements;
624 	buf_ring->base = vzalloc(buf_ring->len);
625 
626 	if (!buf_ring->base) {
627 		dma_free_coherent(mhi_cntrl->cntrl_dev, tre_ring->alloc_size,
628 				  tre_ring->pre_aligned, tre_ring->dma_handle);
629 		return -ENOMEM;
630 	}
631 
632 	tmp = le32_to_cpu(chan_ctxt->chcfg);
633 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
634 	tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_ENABLED);
635 	chan_ctxt->chcfg = cpu_to_le32(tmp);
636 
637 	chan_ctxt->rbase = cpu_to_le64(tre_ring->iommu_base);
638 	chan_ctxt->rp = chan_ctxt->wp = chan_ctxt->rbase;
639 	chan_ctxt->rlen = cpu_to_le64(tre_ring->len);
640 	tre_ring->ctxt_wp = &chan_ctxt->wp;
641 
642 	tre_ring->rp = tre_ring->wp = tre_ring->base;
643 	buf_ring->rp = buf_ring->wp = buf_ring->base;
644 	mhi_chan->db_cfg.db_mode = 1;
645 
646 	/* Update to all cores */
647 	smp_wmb();
648 
649 	return 0;
650 }
651 
652 static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
653 			const struct mhi_controller_config *config)
654 {
655 	struct mhi_event *mhi_event;
656 	const struct mhi_event_config *event_cfg;
657 	struct device *dev = mhi_cntrl->cntrl_dev;
658 	int i, num;
659 
660 	num = config->num_events;
661 	mhi_cntrl->total_ev_rings = num;
662 	mhi_cntrl->mhi_event = kcalloc(num, sizeof(*mhi_cntrl->mhi_event),
663 				       GFP_KERNEL);
664 	if (!mhi_cntrl->mhi_event)
665 		return -ENOMEM;
666 
667 	/* Populate event ring */
668 	mhi_event = mhi_cntrl->mhi_event;
669 	for (i = 0; i < num; i++) {
670 		event_cfg = &config->event_cfg[i];
671 
672 		mhi_event->er_index = i;
673 		mhi_event->ring.elements = event_cfg->num_elements;
674 		mhi_event->intmod = event_cfg->irq_moderation_ms;
675 		mhi_event->irq = event_cfg->irq;
676 
677 		if (event_cfg->channel != U32_MAX) {
678 			/* This event ring has a dedicated channel */
679 			mhi_event->chan = event_cfg->channel;
680 			if (mhi_event->chan >= mhi_cntrl->max_chan) {
681 				dev_err(dev,
682 					"Event Ring channel not available\n");
683 				goto error_ev_cfg;
684 			}
685 
686 			mhi_event->mhi_chan =
687 				&mhi_cntrl->mhi_chan[mhi_event->chan];
688 		}
689 
690 		/* Priority is fixed to 1 for now */
691 		mhi_event->priority = 1;
692 
693 		mhi_event->db_cfg.brstmode = event_cfg->mode;
694 		if (MHI_INVALID_BRSTMODE(mhi_event->db_cfg.brstmode))
695 			goto error_ev_cfg;
696 
697 		if (mhi_event->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
698 			mhi_event->db_cfg.process_db = mhi_db_brstmode;
699 		else
700 			mhi_event->db_cfg.process_db = mhi_db_brstmode_disable;
701 
702 		mhi_event->data_type = event_cfg->data_type;
703 
704 		switch (mhi_event->data_type) {
705 		case MHI_ER_DATA:
706 			mhi_event->process_event = mhi_process_data_event_ring;
707 			break;
708 		case MHI_ER_CTRL:
709 			mhi_event->process_event = mhi_process_ctrl_ev_ring;
710 			break;
711 		default:
712 			dev_err(dev, "Event Ring type not supported\n");
713 			goto error_ev_cfg;
714 		}
715 
716 		mhi_event->hw_ring = event_cfg->hardware_event;
717 		if (mhi_event->hw_ring)
718 			mhi_cntrl->hw_ev_rings++;
719 		else
720 			mhi_cntrl->sw_ev_rings++;
721 
722 		mhi_event->cl_manage = event_cfg->client_managed;
723 		mhi_event->offload_ev = event_cfg->offload_channel;
724 		mhi_event++;
725 	}
726 
727 	return 0;
728 
729 error_ev_cfg:
730 
731 	kfree(mhi_cntrl->mhi_event);
732 	return -EINVAL;
733 }
734 
735 static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
736 			const struct mhi_controller_config *config)
737 {
738 	const struct mhi_channel_config *ch_cfg;
739 	struct device *dev = mhi_cntrl->cntrl_dev;
740 	int i;
741 	u32 chan;
742 
743 	mhi_cntrl->max_chan = config->max_channels;
744 
745 	/*
746 	 * The allocation of MHI channels can exceed 32KB in some scenarios,
747 	 * so to avoid any memory possible allocation failures, vzalloc is
748 	 * used here
749 	 */
750 	mhi_cntrl->mhi_chan = vzalloc(mhi_cntrl->max_chan *
751 				      sizeof(*mhi_cntrl->mhi_chan));
752 	if (!mhi_cntrl->mhi_chan)
753 		return -ENOMEM;
754 
755 	INIT_LIST_HEAD(&mhi_cntrl->lpm_chans);
756 
757 	/* Populate channel configurations */
758 	for (i = 0; i < config->num_channels; i++) {
759 		struct mhi_chan *mhi_chan;
760 
761 		ch_cfg = &config->ch_cfg[i];
762 
763 		chan = ch_cfg->num;
764 		if (chan >= mhi_cntrl->max_chan) {
765 			dev_err(dev, "Channel %d not available\n", chan);
766 			goto error_chan_cfg;
767 		}
768 
769 		mhi_chan = &mhi_cntrl->mhi_chan[chan];
770 		mhi_chan->name = ch_cfg->name;
771 		mhi_chan->chan = chan;
772 
773 		mhi_chan->tre_ring.elements = ch_cfg->num_elements;
774 		if (!mhi_chan->tre_ring.elements)
775 			goto error_chan_cfg;
776 
777 		/*
778 		 * For some channels, local ring length should be bigger than
779 		 * the transfer ring length due to internal logical channels
780 		 * in device. So host can queue much more buffers than transfer
781 		 * ring length. Example, RSC channels should have a larger local
782 		 * channel length than transfer ring length.
783 		 */
784 		mhi_chan->buf_ring.elements = ch_cfg->local_elements;
785 		if (!mhi_chan->buf_ring.elements)
786 			mhi_chan->buf_ring.elements = mhi_chan->tre_ring.elements;
787 		mhi_chan->er_index = ch_cfg->event_ring;
788 		mhi_chan->dir = ch_cfg->dir;
789 
790 		/*
791 		 * For most channels, chtype is identical to channel directions.
792 		 * So, if it is not defined then assign channel direction to
793 		 * chtype
794 		 */
795 		mhi_chan->type = ch_cfg->type;
796 		if (!mhi_chan->type)
797 			mhi_chan->type = (enum mhi_ch_type)mhi_chan->dir;
798 
799 		mhi_chan->ee_mask = ch_cfg->ee_mask;
800 		mhi_chan->db_cfg.pollcfg = ch_cfg->pollcfg;
801 		mhi_chan->lpm_notify = ch_cfg->lpm_notify;
802 		mhi_chan->offload_ch = ch_cfg->offload_channel;
803 		mhi_chan->db_cfg.reset_req = ch_cfg->doorbell_mode_switch;
804 		mhi_chan->pre_alloc = ch_cfg->auto_queue;
805 		mhi_chan->wake_capable = ch_cfg->wake_capable;
806 
807 		/*
808 		 * If MHI host allocates buffers, then the channel direction
809 		 * should be DMA_FROM_DEVICE
810 		 */
811 		if (mhi_chan->pre_alloc && mhi_chan->dir != DMA_FROM_DEVICE) {
812 			dev_err(dev, "Invalid channel configuration\n");
813 			goto error_chan_cfg;
814 		}
815 
816 		/*
817 		 * Bi-directional and direction less channel must be an
818 		 * offload channel
819 		 */
820 		if ((mhi_chan->dir == DMA_BIDIRECTIONAL ||
821 		     mhi_chan->dir == DMA_NONE) && !mhi_chan->offload_ch) {
822 			dev_err(dev, "Invalid channel configuration\n");
823 			goto error_chan_cfg;
824 		}
825 
826 		if (!mhi_chan->offload_ch) {
827 			mhi_chan->db_cfg.brstmode = ch_cfg->doorbell;
828 			if (MHI_INVALID_BRSTMODE(mhi_chan->db_cfg.brstmode)) {
829 				dev_err(dev, "Invalid Door bell mode\n");
830 				goto error_chan_cfg;
831 			}
832 		}
833 
834 		if (mhi_chan->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
835 			mhi_chan->db_cfg.process_db = mhi_db_brstmode;
836 		else
837 			mhi_chan->db_cfg.process_db = mhi_db_brstmode_disable;
838 
839 		mhi_chan->configured = true;
840 
841 		if (mhi_chan->lpm_notify)
842 			list_add_tail(&mhi_chan->node, &mhi_cntrl->lpm_chans);
843 	}
844 
845 	return 0;
846 
847 error_chan_cfg:
848 	vfree(mhi_cntrl->mhi_chan);
849 
850 	return -EINVAL;
851 }
852 
853 static int parse_config(struct mhi_controller *mhi_cntrl,
854 			const struct mhi_controller_config *config)
855 {
856 	int ret;
857 
858 	/* Parse MHI channel configuration */
859 	ret = parse_ch_cfg(mhi_cntrl, config);
860 	if (ret)
861 		return ret;
862 
863 	/* Parse MHI event configuration */
864 	ret = parse_ev_cfg(mhi_cntrl, config);
865 	if (ret)
866 		goto error_ev_cfg;
867 
868 	mhi_cntrl->timeout_ms = config->timeout_ms;
869 	if (!mhi_cntrl->timeout_ms)
870 		mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;
871 
872 	mhi_cntrl->bounce_buf = config->use_bounce_buf;
873 	mhi_cntrl->buffer_len = config->buf_len;
874 	if (!mhi_cntrl->buffer_len)
875 		mhi_cntrl->buffer_len = MHI_MAX_MTU;
876 
877 	/* By default, host is allowed to ring DB in both M0 and M2 states */
878 	mhi_cntrl->db_access = MHI_PM_M0 | MHI_PM_M2;
879 	if (config->m2_no_db)
880 		mhi_cntrl->db_access &= ~MHI_PM_M2;
881 
882 	return 0;
883 
884 error_ev_cfg:
885 	vfree(mhi_cntrl->mhi_chan);
886 
887 	return ret;
888 }
889 
890 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
891 			    const struct mhi_controller_config *config)
892 {
893 	struct mhi_event *mhi_event;
894 	struct mhi_chan *mhi_chan;
895 	struct mhi_cmd *mhi_cmd;
896 	struct mhi_device *mhi_dev;
897 	u32 soc_info;
898 	int ret, i;
899 
900 	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
901 	    !mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
902 	    !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
903 	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs ||
904 	    !mhi_cntrl->irq || !mhi_cntrl->reg_len)
905 		return -EINVAL;
906 
907 	ret = parse_config(mhi_cntrl, config);
908 	if (ret)
909 		return -EINVAL;
910 
911 	mhi_cntrl->mhi_cmd = kcalloc(NR_OF_CMD_RINGS,
912 				     sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
913 	if (!mhi_cntrl->mhi_cmd) {
914 		ret = -ENOMEM;
915 		goto err_free_event;
916 	}
917 
918 	INIT_LIST_HEAD(&mhi_cntrl->transition_list);
919 	mutex_init(&mhi_cntrl->pm_mutex);
920 	rwlock_init(&mhi_cntrl->pm_lock);
921 	spin_lock_init(&mhi_cntrl->transition_lock);
922 	spin_lock_init(&mhi_cntrl->wlock);
923 	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
924 	init_waitqueue_head(&mhi_cntrl->state_event);
925 
926 	mhi_cntrl->hiprio_wq = alloc_ordered_workqueue("mhi_hiprio_wq", WQ_HIGHPRI);
927 	if (!mhi_cntrl->hiprio_wq) {
928 		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
929 		ret = -ENOMEM;
930 		goto err_free_cmd;
931 	}
932 
933 	mhi_cmd = mhi_cntrl->mhi_cmd;
934 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
935 		spin_lock_init(&mhi_cmd->lock);
936 
937 	mhi_event = mhi_cntrl->mhi_event;
938 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
939 		/* Skip for offload events */
940 		if (mhi_event->offload_ev)
941 			continue;
942 
943 		mhi_event->mhi_cntrl = mhi_cntrl;
944 		spin_lock_init(&mhi_event->lock);
945 		if (mhi_event->data_type == MHI_ER_CTRL)
946 			tasklet_init(&mhi_event->task, mhi_ctrl_ev_task,
947 				     (ulong)mhi_event);
948 		else
949 			tasklet_init(&mhi_event->task, mhi_ev_task,
950 				     (ulong)mhi_event);
951 	}
952 
953 	mhi_chan = mhi_cntrl->mhi_chan;
954 	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
955 		mutex_init(&mhi_chan->mutex);
956 		init_completion(&mhi_chan->completion);
957 		rwlock_init(&mhi_chan->lock);
958 
959 		/* used in setting bei field of TRE */
960 		mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
961 		mhi_chan->intmod = mhi_event->intmod;
962 	}
963 
964 	if (mhi_cntrl->bounce_buf) {
965 		mhi_cntrl->map_single = mhi_map_single_use_bb;
966 		mhi_cntrl->unmap_single = mhi_unmap_single_use_bb;
967 	} else {
968 		mhi_cntrl->map_single = mhi_map_single_no_bb;
969 		mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
970 	}
971 
972 	/* Read the MHI device info */
973 	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
974 			   SOC_HW_VERSION_OFFS, &soc_info);
975 	if (ret)
976 		goto err_destroy_wq;
977 
978 	mhi_cntrl->family_number = FIELD_GET(SOC_HW_VERSION_FAM_NUM_BMSK, soc_info);
979 	mhi_cntrl->device_number = FIELD_GET(SOC_HW_VERSION_DEV_NUM_BMSK, soc_info);
980 	mhi_cntrl->major_version = FIELD_GET(SOC_HW_VERSION_MAJOR_VER_BMSK, soc_info);
981 	mhi_cntrl->minor_version = FIELD_GET(SOC_HW_VERSION_MINOR_VER_BMSK, soc_info);
982 
983 	mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
984 	if (mhi_cntrl->index < 0) {
985 		ret = mhi_cntrl->index;
986 		goto err_destroy_wq;
987 	}
988 
989 	ret = mhi_init_irq_setup(mhi_cntrl);
990 	if (ret)
991 		goto err_ida_free;
992 
993 	/* Register controller with MHI bus */
994 	mhi_dev = mhi_alloc_device(mhi_cntrl);
995 	if (IS_ERR(mhi_dev)) {
996 		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n");
997 		ret = PTR_ERR(mhi_dev);
998 		goto error_setup_irq;
999 	}
1000 
1001 	mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
1002 	mhi_dev->mhi_cntrl = mhi_cntrl;
1003 	dev_set_name(&mhi_dev->dev, "mhi%d", mhi_cntrl->index);
1004 	mhi_dev->name = dev_name(&mhi_dev->dev);
1005 
1006 	/* Init wakeup source */
1007 	device_init_wakeup(&mhi_dev->dev, true);
1008 
1009 	ret = device_add(&mhi_dev->dev);
1010 	if (ret)
1011 		goto err_release_dev;
1012 
1013 	mhi_cntrl->mhi_dev = mhi_dev;
1014 
1015 	mhi_create_debugfs(mhi_cntrl);
1016 
1017 	return 0;
1018 
1019 err_release_dev:
1020 	put_device(&mhi_dev->dev);
1021 error_setup_irq:
1022 	mhi_deinit_free_irq(mhi_cntrl);
1023 err_ida_free:
1024 	ida_free(&mhi_controller_ida, mhi_cntrl->index);
1025 err_destroy_wq:
1026 	destroy_workqueue(mhi_cntrl->hiprio_wq);
1027 err_free_cmd:
1028 	kfree(mhi_cntrl->mhi_cmd);
1029 err_free_event:
1030 	kfree(mhi_cntrl->mhi_event);
1031 	vfree(mhi_cntrl->mhi_chan);
1032 
1033 	return ret;
1034 }
1035 EXPORT_SYMBOL_GPL(mhi_register_controller);
1036 
1037 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
1038 {
1039 	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
1040 	struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
1041 	unsigned int i;
1042 
1043 	mhi_deinit_free_irq(mhi_cntrl);
1044 	mhi_destroy_debugfs(mhi_cntrl);
1045 
1046 	destroy_workqueue(mhi_cntrl->hiprio_wq);
1047 	kfree(mhi_cntrl->mhi_cmd);
1048 	kfree(mhi_cntrl->mhi_event);
1049 
1050 	/* Drop the references to MHI devices created for channels */
1051 	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
1052 		if (!mhi_chan->mhi_dev)
1053 			continue;
1054 
1055 		put_device(&mhi_chan->mhi_dev->dev);
1056 	}
1057 	vfree(mhi_cntrl->mhi_chan);
1058 
1059 	device_del(&mhi_dev->dev);
1060 	put_device(&mhi_dev->dev);
1061 
1062 	ida_free(&mhi_controller_ida, mhi_cntrl->index);
1063 }
1064 EXPORT_SYMBOL_GPL(mhi_unregister_controller);
1065 
1066 struct mhi_controller *mhi_alloc_controller(void)
1067 {
1068 	struct mhi_controller *mhi_cntrl;
1069 
1070 	mhi_cntrl = kzalloc(sizeof(*mhi_cntrl), GFP_KERNEL);
1071 
1072 	return mhi_cntrl;
1073 }
1074 EXPORT_SYMBOL_GPL(mhi_alloc_controller);
1075 
1076 void mhi_free_controller(struct mhi_controller *mhi_cntrl)
1077 {
1078 	kfree(mhi_cntrl);
1079 }
1080 EXPORT_SYMBOL_GPL(mhi_free_controller);
1081 
1082 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
1083 {
1084 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
1085 	u32 bhi_off, bhie_off;
1086 	int ret;
1087 
1088 	mutex_lock(&mhi_cntrl->pm_mutex);
1089 
1090 	ret = mhi_init_dev_ctxt(mhi_cntrl);
1091 	if (ret)
1092 		goto error_dev_ctxt;
1093 
1094 	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIOFF, &bhi_off);
1095 	if (ret) {
1096 		dev_err(dev, "Error getting BHI offset\n");
1097 		goto error_reg_offset;
1098 	}
1099 
1100 	if (bhi_off >= mhi_cntrl->reg_len) {
1101 		dev_err(dev, "BHI offset: 0x%x is out of range: 0x%zx\n",
1102 			bhi_off, mhi_cntrl->reg_len);
1103 		ret = -EINVAL;
1104 		goto error_reg_offset;
1105 	}
1106 	mhi_cntrl->bhi = mhi_cntrl->regs + bhi_off;
1107 
1108 	if (mhi_cntrl->fbc_download || mhi_cntrl->rddm_size) {
1109 		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF,
1110 				   &bhie_off);
1111 		if (ret) {
1112 			dev_err(dev, "Error getting BHIE offset\n");
1113 			goto error_reg_offset;
1114 		}
1115 
1116 		if (bhie_off >= mhi_cntrl->reg_len) {
1117 			dev_err(dev,
1118 				"BHIe offset: 0x%x is out of range: 0x%zx\n",
1119 				bhie_off, mhi_cntrl->reg_len);
1120 			ret = -EINVAL;
1121 			goto error_reg_offset;
1122 		}
1123 		mhi_cntrl->bhie = mhi_cntrl->regs + bhie_off;
1124 	}
1125 
1126 	if (mhi_cntrl->rddm_size) {
1127 		/*
1128 		 * This controller supports RDDM, so we need to manually clear
1129 		 * BHIE RX registers since POR values are undefined.
1130 		 */
1131 		memset_io(mhi_cntrl->bhie + BHIE_RXVECADDR_LOW_OFFS,
1132 			  0, BHIE_RXVECSTATUS_OFFS - BHIE_RXVECADDR_LOW_OFFS +
1133 			  4);
1134 		/*
1135 		 * Allocate RDDM table for debugging purpose if specified
1136 		 */
1137 		mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
1138 				     mhi_cntrl->rddm_size);
1139 		if (mhi_cntrl->rddm_image) {
1140 			ret = mhi_rddm_prepare(mhi_cntrl,
1141 					       mhi_cntrl->rddm_image);
1142 			if (ret) {
1143 				mhi_free_bhie_table(mhi_cntrl,
1144 						    mhi_cntrl->rddm_image);
1145 				goto error_reg_offset;
1146 			}
1147 		}
1148 	}
1149 
1150 	mutex_unlock(&mhi_cntrl->pm_mutex);
1151 
1152 	return 0;
1153 
1154 error_reg_offset:
1155 	mhi_deinit_dev_ctxt(mhi_cntrl);
1156 
1157 error_dev_ctxt:
1158 	mutex_unlock(&mhi_cntrl->pm_mutex);
1159 
1160 	return ret;
1161 }
1162 EXPORT_SYMBOL_GPL(mhi_prepare_for_power_up);
1163 
1164 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
1165 {
1166 	if (mhi_cntrl->fbc_image) {
1167 		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
1168 		mhi_cntrl->fbc_image = NULL;
1169 	}
1170 
1171 	if (mhi_cntrl->rddm_image) {
1172 		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
1173 		mhi_cntrl->rddm_image = NULL;
1174 	}
1175 
1176 	mhi_cntrl->bhi = NULL;
1177 	mhi_cntrl->bhie = NULL;
1178 
1179 	mhi_deinit_dev_ctxt(mhi_cntrl);
1180 }
1181 EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
1182 
1183 static void mhi_release_device(struct device *dev)
1184 {
1185 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1186 
1187 	/*
1188 	 * We need to set the mhi_chan->mhi_dev to NULL here since the MHI
1189 	 * devices for the channels will only get created if the mhi_dev
1190 	 * associated with it is NULL. This scenario will happen during the
1191 	 * controller suspend and resume.
1192 	 */
1193 	if (mhi_dev->ul_chan)
1194 		mhi_dev->ul_chan->mhi_dev = NULL;
1195 
1196 	if (mhi_dev->dl_chan)
1197 		mhi_dev->dl_chan->mhi_dev = NULL;
1198 
1199 	kfree(mhi_dev);
1200 }
1201 
1202 struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
1203 {
1204 	struct mhi_device *mhi_dev;
1205 	struct device *dev;
1206 
1207 	mhi_dev = kzalloc(sizeof(*mhi_dev), GFP_KERNEL);
1208 	if (!mhi_dev)
1209 		return ERR_PTR(-ENOMEM);
1210 
1211 	dev = &mhi_dev->dev;
1212 	device_initialize(dev);
1213 	dev->bus = &mhi_bus_type;
1214 	dev->release = mhi_release_device;
1215 
1216 	if (mhi_cntrl->mhi_dev) {
1217 		/* for MHI client devices, parent is the MHI controller device */
1218 		dev->parent = &mhi_cntrl->mhi_dev->dev;
1219 	} else {
1220 		/* for MHI controller device, parent is the bus device (e.g. pci device) */
1221 		dev->parent = mhi_cntrl->cntrl_dev;
1222 	}
1223 
1224 	mhi_dev->mhi_cntrl = mhi_cntrl;
1225 	mhi_dev->dev_wake = 0;
1226 
1227 	return mhi_dev;
1228 }
1229 
1230 static int mhi_driver_probe(struct device *dev)
1231 {
1232 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1233 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1234 	struct device_driver *drv = dev->driver;
1235 	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1236 	struct mhi_event *mhi_event;
1237 	struct mhi_chan *ul_chan = mhi_dev->ul_chan;
1238 	struct mhi_chan *dl_chan = mhi_dev->dl_chan;
1239 	int ret;
1240 
1241 	/* Bring device out of LPM */
1242 	ret = mhi_device_get_sync(mhi_dev);
1243 	if (ret)
1244 		return ret;
1245 
1246 	ret = -EINVAL;
1247 
1248 	if (ul_chan) {
1249 		/*
1250 		 * If channel supports LPM notifications then status_cb should
1251 		 * be provided
1252 		 */
1253 		if (ul_chan->lpm_notify && !mhi_drv->status_cb)
1254 			goto exit_probe;
1255 
1256 		/* For non-offload channels then xfer_cb should be provided */
1257 		if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb)
1258 			goto exit_probe;
1259 
1260 		ul_chan->xfer_cb = mhi_drv->ul_xfer_cb;
1261 	}
1262 
1263 	ret = -EINVAL;
1264 	if (dl_chan) {
1265 		/*
1266 		 * If channel supports LPM notifications then status_cb should
1267 		 * be provided
1268 		 */
1269 		if (dl_chan->lpm_notify && !mhi_drv->status_cb)
1270 			goto exit_probe;
1271 
1272 		/* For non-offload channels then xfer_cb should be provided */
1273 		if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb)
1274 			goto exit_probe;
1275 
1276 		mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index];
1277 
1278 		/*
1279 		 * If the channel event ring is managed by client, then
1280 		 * status_cb must be provided so that the framework can
1281 		 * notify pending data
1282 		 */
1283 		if (mhi_event->cl_manage && !mhi_drv->status_cb)
1284 			goto exit_probe;
1285 
1286 		dl_chan->xfer_cb = mhi_drv->dl_xfer_cb;
1287 	}
1288 
1289 	/* Call the user provided probe function */
1290 	ret = mhi_drv->probe(mhi_dev, mhi_dev->id);
1291 	if (ret)
1292 		goto exit_probe;
1293 
1294 	mhi_device_put(mhi_dev);
1295 
1296 	return ret;
1297 
1298 exit_probe:
1299 	mhi_unprepare_from_transfer(mhi_dev);
1300 
1301 	mhi_device_put(mhi_dev);
1302 
1303 	return ret;
1304 }
1305 
1306 static int mhi_driver_remove(struct device *dev)
1307 {
1308 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1309 	struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver);
1310 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1311 	struct mhi_chan *mhi_chan;
1312 	enum mhi_ch_state ch_state[] = {
1313 		MHI_CH_STATE_DISABLED,
1314 		MHI_CH_STATE_DISABLED
1315 	};
1316 	int dir;
1317 
1318 	/* Skip if it is a controller device */
1319 	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1320 		return 0;
1321 
1322 	/* Reset both channels */
1323 	for (dir = 0; dir < 2; dir++) {
1324 		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1325 
1326 		if (!mhi_chan)
1327 			continue;
1328 
1329 		/* Wake all threads waiting for completion */
1330 		write_lock_irq(&mhi_chan->lock);
1331 		mhi_chan->ccs = MHI_EV_CC_INVALID;
1332 		complete_all(&mhi_chan->completion);
1333 		write_unlock_irq(&mhi_chan->lock);
1334 
1335 		/* Set the channel state to disabled */
1336 		mutex_lock(&mhi_chan->mutex);
1337 		write_lock_irq(&mhi_chan->lock);
1338 		ch_state[dir] = mhi_chan->ch_state;
1339 		mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED;
1340 		write_unlock_irq(&mhi_chan->lock);
1341 
1342 		/* Reset the non-offload channel */
1343 		if (!mhi_chan->offload_ch)
1344 			mhi_reset_chan(mhi_cntrl, mhi_chan);
1345 
1346 		mutex_unlock(&mhi_chan->mutex);
1347 	}
1348 
1349 	mhi_drv->remove(mhi_dev);
1350 
1351 	/* De-init channel if it was enabled */
1352 	for (dir = 0; dir < 2; dir++) {
1353 		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1354 
1355 		if (!mhi_chan)
1356 			continue;
1357 
1358 		mutex_lock(&mhi_chan->mutex);
1359 
1360 		if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
1361 		     ch_state[dir] == MHI_CH_STATE_STOP) &&
1362 		    !mhi_chan->offload_ch)
1363 			mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
1364 
1365 		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
1366 
1367 		mutex_unlock(&mhi_chan->mutex);
1368 	}
1369 
1370 	while (mhi_dev->dev_wake)
1371 		mhi_device_put(mhi_dev);
1372 
1373 	return 0;
1374 }
1375 
1376 int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner)
1377 {
1378 	struct device_driver *driver = &mhi_drv->driver;
1379 
1380 	if (!mhi_drv->probe || !mhi_drv->remove)
1381 		return -EINVAL;
1382 
1383 	driver->bus = &mhi_bus_type;
1384 	driver->owner = owner;
1385 	driver->probe = mhi_driver_probe;
1386 	driver->remove = mhi_driver_remove;
1387 
1388 	return driver_register(driver);
1389 }
1390 EXPORT_SYMBOL_GPL(__mhi_driver_register);
1391 
1392 void mhi_driver_unregister(struct mhi_driver *mhi_drv)
1393 {
1394 	driver_unregister(&mhi_drv->driver);
1395 }
1396 EXPORT_SYMBOL_GPL(mhi_driver_unregister);
1397 
1398 static int mhi_uevent(struct device *dev, struct kobj_uevent_env *env)
1399 {
1400 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1401 
1402 	return add_uevent_var(env, "MODALIAS=" MHI_DEVICE_MODALIAS_FMT,
1403 					mhi_dev->name);
1404 }
1405 
1406 static int mhi_match(struct device *dev, struct device_driver *drv)
1407 {
1408 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1409 	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1410 	const struct mhi_device_id *id;
1411 
1412 	/*
1413 	 * If the device is a controller type then there is no client driver
1414 	 * associated with it
1415 	 */
1416 	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1417 		return 0;
1418 
1419 	for (id = mhi_drv->id_table; id->chan[0]; id++)
1420 		if (!strcmp(mhi_dev->name, id->chan)) {
1421 			mhi_dev->id = id;
1422 			return 1;
1423 		}
1424 
1425 	return 0;
1426 };
1427 
1428 struct bus_type mhi_bus_type = {
1429 	.name = "mhi",
1430 	.dev_name = "mhi",
1431 	.match = mhi_match,
1432 	.uevent = mhi_uevent,
1433 	.dev_groups = mhi_dev_groups,
1434 };
1435 
1436 static int __init mhi_init(void)
1437 {
1438 	mhi_debugfs_init();
1439 	return bus_register(&mhi_bus_type);
1440 }
1441 
1442 static void __exit mhi_exit(void)
1443 {
1444 	mhi_debugfs_exit();
1445 	bus_unregister(&mhi_bus_type);
1446 }
1447 
1448 postcore_initcall(mhi_init);
1449 module_exit(mhi_exit);
1450 
1451 MODULE_LICENSE("GPL v2");
1452 MODULE_DESCRIPTION("MHI Host Interface");
1453