xref: /linux/drivers/bus/mhi/host/init.c (revision cbac924200b838cfb8d8b1415113d788089dc50b)
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 snprintf(buf, PAGE_SIZE, "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 += snprintf(buf + cnt, PAGE_SIZE - cnt,
104 				"OEMPKHASH[%d]: 0x%x\n", i,
105 				mhi_cntrl->oem_pk_hash[i]);
106 
107 	return cnt;
108 }
109 static DEVICE_ATTR_RO(oem_pk_hash);
110 
111 static struct attribute *mhi_dev_attrs[] = {
112 	&dev_attr_serial_number.attr,
113 	&dev_attr_oem_pk_hash.attr,
114 	NULL,
115 };
116 ATTRIBUTE_GROUPS(mhi_dev);
117 
118 /* MHI protocol requires the transfer ring to be aligned with ring length */
119 static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
120 				  struct mhi_ring *ring,
121 				  u64 len)
122 {
123 	ring->alloc_size = len + (len - 1);
124 	ring->pre_aligned = dma_alloc_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
125 					       &ring->dma_handle, GFP_KERNEL);
126 	if (!ring->pre_aligned)
127 		return -ENOMEM;
128 
129 	ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);
130 	ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);
131 
132 	return 0;
133 }
134 
135 void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)
136 {
137 	int i;
138 	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
139 
140 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
141 		if (mhi_event->offload_ev)
142 			continue;
143 
144 		free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
145 	}
146 
147 	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
148 }
149 
150 int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
151 {
152 	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
153 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
154 	unsigned long irq_flags = IRQF_SHARED | IRQF_NO_SUSPEND;
155 	int i, ret;
156 
157 	/* if controller driver has set irq_flags, use it */
158 	if (mhi_cntrl->irq_flags)
159 		irq_flags = mhi_cntrl->irq_flags;
160 
161 	/* Setup BHI_INTVEC IRQ */
162 	ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handler,
163 				   mhi_intvec_threaded_handler,
164 				   irq_flags,
165 				   "bhi", mhi_cntrl);
166 	if (ret)
167 		return ret;
168 
169 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
170 		if (mhi_event->offload_ev)
171 			continue;
172 
173 		if (mhi_event->irq >= mhi_cntrl->nr_irqs) {
174 			dev_err(dev, "irq %d not available for event ring\n",
175 				mhi_event->irq);
176 			ret = -EINVAL;
177 			goto error_request;
178 		}
179 
180 		ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
181 				  mhi_irq_handler,
182 				  irq_flags,
183 				  "mhi", mhi_event);
184 		if (ret) {
185 			dev_err(dev, "Error requesting irq:%d for ev:%d\n",
186 				mhi_cntrl->irq[mhi_event->irq], i);
187 			goto error_request;
188 		}
189 	}
190 
191 	return 0;
192 
193 error_request:
194 	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
195 		if (mhi_event->offload_ev)
196 			continue;
197 
198 		free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
199 	}
200 	free_irq(mhi_cntrl->irq[0], mhi_cntrl);
201 
202 	return ret;
203 }
204 
205 void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl)
206 {
207 	int i;
208 	struct mhi_ctxt *mhi_ctxt = mhi_cntrl->mhi_ctxt;
209 	struct mhi_cmd *mhi_cmd;
210 	struct mhi_event *mhi_event;
211 	struct mhi_ring *ring;
212 
213 	mhi_cmd = mhi_cntrl->mhi_cmd;
214 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++) {
215 		ring = &mhi_cmd->ring;
216 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
217 				  ring->pre_aligned, ring->dma_handle);
218 		ring->base = NULL;
219 		ring->iommu_base = 0;
220 	}
221 
222 	dma_free_coherent(mhi_cntrl->cntrl_dev,
223 			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
224 			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
225 
226 	mhi_event = mhi_cntrl->mhi_event;
227 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
228 		if (mhi_event->offload_ev)
229 			continue;
230 
231 		ring = &mhi_event->ring;
232 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
233 				  ring->pre_aligned, ring->dma_handle);
234 		ring->base = NULL;
235 		ring->iommu_base = 0;
236 	}
237 
238 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->er_ctxt) *
239 			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
240 			  mhi_ctxt->er_ctxt_addr);
241 
242 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->chan_ctxt) *
243 			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
244 			  mhi_ctxt->chan_ctxt_addr);
245 
246 	kfree(mhi_ctxt);
247 	mhi_cntrl->mhi_ctxt = NULL;
248 }
249 
250 int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
251 {
252 	struct mhi_ctxt *mhi_ctxt;
253 	struct mhi_chan_ctxt *chan_ctxt;
254 	struct mhi_event_ctxt *er_ctxt;
255 	struct mhi_cmd_ctxt *cmd_ctxt;
256 	struct mhi_chan *mhi_chan;
257 	struct mhi_event *mhi_event;
258 	struct mhi_cmd *mhi_cmd;
259 	u32 tmp;
260 	int ret = -ENOMEM, i;
261 
262 	atomic_set(&mhi_cntrl->dev_wake, 0);
263 	atomic_set(&mhi_cntrl->pending_pkts, 0);
264 
265 	mhi_ctxt = kzalloc(sizeof(*mhi_ctxt), GFP_KERNEL);
266 	if (!mhi_ctxt)
267 		return -ENOMEM;
268 
269 	/* Setup channel ctxt */
270 	mhi_ctxt->chan_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
271 						 sizeof(*mhi_ctxt->chan_ctxt) *
272 						 mhi_cntrl->max_chan,
273 						 &mhi_ctxt->chan_ctxt_addr,
274 						 GFP_KERNEL);
275 	if (!mhi_ctxt->chan_ctxt)
276 		goto error_alloc_chan_ctxt;
277 
278 	mhi_chan = mhi_cntrl->mhi_chan;
279 	chan_ctxt = mhi_ctxt->chan_ctxt;
280 	for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
281 		/* Skip if it is an offload channel */
282 		if (mhi_chan->offload_ch)
283 			continue;
284 
285 		tmp = le32_to_cpu(chan_ctxt->chcfg);
286 		tmp &= ~CHAN_CTX_CHSTATE_MASK;
287 		tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
288 		tmp &= ~CHAN_CTX_BRSTMODE_MASK;
289 		tmp |= FIELD_PREP(CHAN_CTX_BRSTMODE_MASK, mhi_chan->db_cfg.brstmode);
290 		tmp &= ~CHAN_CTX_POLLCFG_MASK;
291 		tmp |= FIELD_PREP(CHAN_CTX_POLLCFG_MASK, mhi_chan->db_cfg.pollcfg);
292 		chan_ctxt->chcfg = cpu_to_le32(tmp);
293 
294 		chan_ctxt->chtype = cpu_to_le32(mhi_chan->type);
295 		chan_ctxt->erindex = cpu_to_le32(mhi_chan->er_index);
296 
297 		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
298 		mhi_chan->tre_ring.db_addr = (void __iomem *)&chan_ctxt->wp;
299 	}
300 
301 	/* Setup event context */
302 	mhi_ctxt->er_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
303 					       sizeof(*mhi_ctxt->er_ctxt) *
304 					       mhi_cntrl->total_ev_rings,
305 					       &mhi_ctxt->er_ctxt_addr,
306 					       GFP_KERNEL);
307 	if (!mhi_ctxt->er_ctxt)
308 		goto error_alloc_er_ctxt;
309 
310 	er_ctxt = mhi_ctxt->er_ctxt;
311 	mhi_event = mhi_cntrl->mhi_event;
312 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
313 		     mhi_event++) {
314 		struct mhi_ring *ring = &mhi_event->ring;
315 
316 		/* Skip if it is an offload event */
317 		if (mhi_event->offload_ev)
318 			continue;
319 
320 		tmp = le32_to_cpu(er_ctxt->intmod);
321 		tmp &= ~EV_CTX_INTMODC_MASK;
322 		tmp &= ~EV_CTX_INTMODT_MASK;
323 		tmp |= FIELD_PREP(EV_CTX_INTMODT_MASK, mhi_event->intmod);
324 		er_ctxt->intmod = cpu_to_le32(tmp);
325 
326 		er_ctxt->ertype = cpu_to_le32(MHI_ER_TYPE_VALID);
327 		er_ctxt->msivec = cpu_to_le32(mhi_event->irq);
328 		mhi_event->db_cfg.db_mode = true;
329 
330 		ring->el_size = sizeof(struct mhi_ring_element);
331 		ring->len = ring->el_size * ring->elements;
332 		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
333 		if (ret)
334 			goto error_alloc_er;
335 
336 		/*
337 		 * If the read pointer equals to the write pointer, then the
338 		 * ring is empty
339 		 */
340 		ring->rp = ring->wp = ring->base;
341 		er_ctxt->rbase = cpu_to_le64(ring->iommu_base);
342 		er_ctxt->rp = er_ctxt->wp = er_ctxt->rbase;
343 		er_ctxt->rlen = cpu_to_le64(ring->len);
344 		ring->ctxt_wp = &er_ctxt->wp;
345 	}
346 
347 	/* Setup cmd context */
348 	ret = -ENOMEM;
349 	mhi_ctxt->cmd_ctxt = dma_alloc_coherent(mhi_cntrl->cntrl_dev,
350 						sizeof(*mhi_ctxt->cmd_ctxt) *
351 						NR_OF_CMD_RINGS,
352 						&mhi_ctxt->cmd_ctxt_addr,
353 						GFP_KERNEL);
354 	if (!mhi_ctxt->cmd_ctxt)
355 		goto error_alloc_er;
356 
357 	mhi_cmd = mhi_cntrl->mhi_cmd;
358 	cmd_ctxt = mhi_ctxt->cmd_ctxt;
359 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
360 		struct mhi_ring *ring = &mhi_cmd->ring;
361 
362 		ring->el_size = sizeof(struct mhi_ring_element);
363 		ring->elements = CMD_EL_PER_RING;
364 		ring->len = ring->el_size * ring->elements;
365 		ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
366 		if (ret)
367 			goto error_alloc_cmd;
368 
369 		ring->rp = ring->wp = ring->base;
370 		cmd_ctxt->rbase = cpu_to_le64(ring->iommu_base);
371 		cmd_ctxt->rp = cmd_ctxt->wp = cmd_ctxt->rbase;
372 		cmd_ctxt->rlen = cpu_to_le64(ring->len);
373 		ring->ctxt_wp = &cmd_ctxt->wp;
374 	}
375 
376 	mhi_cntrl->mhi_ctxt = mhi_ctxt;
377 
378 	return 0;
379 
380 error_alloc_cmd:
381 	for (--i, --mhi_cmd; i >= 0; i--, mhi_cmd--) {
382 		struct mhi_ring *ring = &mhi_cmd->ring;
383 
384 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
385 				  ring->pre_aligned, ring->dma_handle);
386 	}
387 	dma_free_coherent(mhi_cntrl->cntrl_dev,
388 			  sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
389 			  mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
390 	i = mhi_cntrl->total_ev_rings;
391 	mhi_event = mhi_cntrl->mhi_event + i;
392 
393 error_alloc_er:
394 	for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
395 		struct mhi_ring *ring = &mhi_event->ring;
396 
397 		if (mhi_event->offload_ev)
398 			continue;
399 
400 		dma_free_coherent(mhi_cntrl->cntrl_dev, ring->alloc_size,
401 				  ring->pre_aligned, ring->dma_handle);
402 	}
403 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->er_ctxt) *
404 			  mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
405 			  mhi_ctxt->er_ctxt_addr);
406 
407 error_alloc_er_ctxt:
408 	dma_free_coherent(mhi_cntrl->cntrl_dev, sizeof(*mhi_ctxt->chan_ctxt) *
409 			  mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
410 			  mhi_ctxt->chan_ctxt_addr);
411 
412 error_alloc_chan_ctxt:
413 	kfree(mhi_ctxt);
414 
415 	return ret;
416 }
417 
418 int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
419 {
420 	u32 val;
421 	int i, ret;
422 	struct mhi_chan *mhi_chan;
423 	struct mhi_event *mhi_event;
424 	void __iomem *base = mhi_cntrl->regs;
425 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
426 	struct {
427 		u32 offset;
428 		u32 mask;
429 		u32 val;
430 	} reg_info[] = {
431 		{
432 			CCABAP_HIGHER, U32_MAX,
433 			upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
434 		},
435 		{
436 			CCABAP_LOWER, U32_MAX,
437 			lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
438 		},
439 		{
440 			ECABAP_HIGHER, U32_MAX,
441 			upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
442 		},
443 		{
444 			ECABAP_LOWER, U32_MAX,
445 			lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
446 		},
447 		{
448 			CRCBAP_HIGHER, U32_MAX,
449 			upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
450 		},
451 		{
452 			CRCBAP_LOWER, U32_MAX,
453 			lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
454 		},
455 		{
456 			MHICFG, MHICFG_NER_MASK,
457 			mhi_cntrl->total_ev_rings,
458 		},
459 		{
460 			MHICFG, MHICFG_NHWER_MASK,
461 			mhi_cntrl->hw_ev_rings,
462 		},
463 		{
464 			MHICTRLBASE_HIGHER, U32_MAX,
465 			upper_32_bits(mhi_cntrl->iova_start),
466 		},
467 		{
468 			MHICTRLBASE_LOWER, U32_MAX,
469 			lower_32_bits(mhi_cntrl->iova_start),
470 		},
471 		{
472 			MHIDATABASE_HIGHER, U32_MAX,
473 			upper_32_bits(mhi_cntrl->iova_start),
474 		},
475 		{
476 			MHIDATABASE_LOWER, U32_MAX,
477 			lower_32_bits(mhi_cntrl->iova_start),
478 		},
479 		{
480 			MHICTRLLIMIT_HIGHER, U32_MAX,
481 			upper_32_bits(mhi_cntrl->iova_stop),
482 		},
483 		{
484 			MHICTRLLIMIT_LOWER, U32_MAX,
485 			lower_32_bits(mhi_cntrl->iova_stop),
486 		},
487 		{
488 			MHIDATALIMIT_HIGHER, U32_MAX,
489 			upper_32_bits(mhi_cntrl->iova_stop),
490 		},
491 		{
492 			MHIDATALIMIT_LOWER, U32_MAX,
493 			lower_32_bits(mhi_cntrl->iova_stop),
494 		},
495 		{ 0, 0, 0 }
496 	};
497 
498 	dev_dbg(dev, "Initializing MHI registers\n");
499 
500 	/* Read channel db offset */
501 	ret = mhi_read_reg(mhi_cntrl, base, CHDBOFF, &val);
502 	if (ret) {
503 		dev_err(dev, "Unable to read CHDBOFF register\n");
504 		return -EIO;
505 	}
506 
507 	/* Setup wake db */
508 	mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
509 	mhi_cntrl->wake_set = false;
510 
511 	/* Setup channel db address for each channel in tre_ring */
512 	mhi_chan = mhi_cntrl->mhi_chan;
513 	for (i = 0; i < mhi_cntrl->max_chan; i++, val += 8, mhi_chan++)
514 		mhi_chan->tre_ring.db_addr = base + val;
515 
516 	/* Read event ring db offset */
517 	ret = mhi_read_reg(mhi_cntrl, base, ERDBOFF, &val);
518 	if (ret) {
519 		dev_err(dev, "Unable to read ERDBOFF register\n");
520 		return -EIO;
521 	}
522 
523 	/* Setup event db address for each ev_ring */
524 	mhi_event = mhi_cntrl->mhi_event;
525 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
526 		if (mhi_event->offload_ev)
527 			continue;
528 
529 		mhi_event->ring.db_addr = base + val;
530 	}
531 
532 	/* Setup DB register for primary CMD rings */
533 	mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER;
534 
535 	/* Write to MMIO registers */
536 	for (i = 0; reg_info[i].offset; i++)
537 		mhi_write_reg_field(mhi_cntrl, base, reg_info[i].offset,
538 				    reg_info[i].mask, reg_info[i].val);
539 
540 	return 0;
541 }
542 
543 void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
544 			  struct mhi_chan *mhi_chan)
545 {
546 	struct mhi_ring *buf_ring;
547 	struct mhi_ring *tre_ring;
548 	struct mhi_chan_ctxt *chan_ctxt;
549 	u32 tmp;
550 
551 	buf_ring = &mhi_chan->buf_ring;
552 	tre_ring = &mhi_chan->tre_ring;
553 	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
554 
555 	if (!chan_ctxt->rbase) /* Already uninitialized */
556 		return;
557 
558 	dma_free_coherent(mhi_cntrl->cntrl_dev, tre_ring->alloc_size,
559 			  tre_ring->pre_aligned, tre_ring->dma_handle);
560 	vfree(buf_ring->base);
561 
562 	buf_ring->base = tre_ring->base = NULL;
563 	tre_ring->ctxt_wp = NULL;
564 	chan_ctxt->rbase = 0;
565 	chan_ctxt->rlen = 0;
566 	chan_ctxt->rp = 0;
567 	chan_ctxt->wp = 0;
568 
569 	tmp = le32_to_cpu(chan_ctxt->chcfg);
570 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
571 	tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED);
572 	chan_ctxt->chcfg = cpu_to_le32(tmp);
573 
574 	/* Update to all cores */
575 	smp_wmb();
576 }
577 
578 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
579 		       struct mhi_chan *mhi_chan)
580 {
581 	struct mhi_ring *buf_ring;
582 	struct mhi_ring *tre_ring;
583 	struct mhi_chan_ctxt *chan_ctxt;
584 	u32 tmp;
585 	int ret;
586 
587 	buf_ring = &mhi_chan->buf_ring;
588 	tre_ring = &mhi_chan->tre_ring;
589 	tre_ring->el_size = sizeof(struct mhi_ring_element);
590 	tre_ring->len = tre_ring->el_size * tre_ring->elements;
591 	chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
592 	ret = mhi_alloc_aligned_ring(mhi_cntrl, tre_ring, tre_ring->len);
593 	if (ret)
594 		return -ENOMEM;
595 
596 	buf_ring->el_size = sizeof(struct mhi_buf_info);
597 	buf_ring->len = buf_ring->el_size * buf_ring->elements;
598 	buf_ring->base = vzalloc(buf_ring->len);
599 
600 	if (!buf_ring->base) {
601 		dma_free_coherent(mhi_cntrl->cntrl_dev, tre_ring->alloc_size,
602 				  tre_ring->pre_aligned, tre_ring->dma_handle);
603 		return -ENOMEM;
604 	}
605 
606 	tmp = le32_to_cpu(chan_ctxt->chcfg);
607 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
608 	tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_ENABLED);
609 	chan_ctxt->chcfg = cpu_to_le32(tmp);
610 
611 	chan_ctxt->rbase = cpu_to_le64(tre_ring->iommu_base);
612 	chan_ctxt->rp = chan_ctxt->wp = chan_ctxt->rbase;
613 	chan_ctxt->rlen = cpu_to_le64(tre_ring->len);
614 	tre_ring->ctxt_wp = &chan_ctxt->wp;
615 
616 	tre_ring->rp = tre_ring->wp = tre_ring->base;
617 	buf_ring->rp = buf_ring->wp = buf_ring->base;
618 	mhi_chan->db_cfg.db_mode = 1;
619 
620 	/* Update to all cores */
621 	smp_wmb();
622 
623 	return 0;
624 }
625 
626 static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
627 			const struct mhi_controller_config *config)
628 {
629 	struct mhi_event *mhi_event;
630 	const struct mhi_event_config *event_cfg;
631 	struct device *dev = mhi_cntrl->cntrl_dev;
632 	int i, num;
633 
634 	num = config->num_events;
635 	mhi_cntrl->total_ev_rings = num;
636 	mhi_cntrl->mhi_event = kcalloc(num, sizeof(*mhi_cntrl->mhi_event),
637 				       GFP_KERNEL);
638 	if (!mhi_cntrl->mhi_event)
639 		return -ENOMEM;
640 
641 	/* Populate event ring */
642 	mhi_event = mhi_cntrl->mhi_event;
643 	for (i = 0; i < num; i++) {
644 		event_cfg = &config->event_cfg[i];
645 
646 		mhi_event->er_index = i;
647 		mhi_event->ring.elements = event_cfg->num_elements;
648 		mhi_event->intmod = event_cfg->irq_moderation_ms;
649 		mhi_event->irq = event_cfg->irq;
650 
651 		if (event_cfg->channel != U32_MAX) {
652 			/* This event ring has a dedicated channel */
653 			mhi_event->chan = event_cfg->channel;
654 			if (mhi_event->chan >= mhi_cntrl->max_chan) {
655 				dev_err(dev,
656 					"Event Ring channel not available\n");
657 				goto error_ev_cfg;
658 			}
659 
660 			mhi_event->mhi_chan =
661 				&mhi_cntrl->mhi_chan[mhi_event->chan];
662 		}
663 
664 		/* Priority is fixed to 1 for now */
665 		mhi_event->priority = 1;
666 
667 		mhi_event->db_cfg.brstmode = event_cfg->mode;
668 		if (MHI_INVALID_BRSTMODE(mhi_event->db_cfg.brstmode))
669 			goto error_ev_cfg;
670 
671 		if (mhi_event->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
672 			mhi_event->db_cfg.process_db = mhi_db_brstmode;
673 		else
674 			mhi_event->db_cfg.process_db = mhi_db_brstmode_disable;
675 
676 		mhi_event->data_type = event_cfg->data_type;
677 
678 		switch (mhi_event->data_type) {
679 		case MHI_ER_DATA:
680 			mhi_event->process_event = mhi_process_data_event_ring;
681 			break;
682 		case MHI_ER_CTRL:
683 			mhi_event->process_event = mhi_process_ctrl_ev_ring;
684 			break;
685 		default:
686 			dev_err(dev, "Event Ring type not supported\n");
687 			goto error_ev_cfg;
688 		}
689 
690 		mhi_event->hw_ring = event_cfg->hardware_event;
691 		if (mhi_event->hw_ring)
692 			mhi_cntrl->hw_ev_rings++;
693 		else
694 			mhi_cntrl->sw_ev_rings++;
695 
696 		mhi_event->cl_manage = event_cfg->client_managed;
697 		mhi_event->offload_ev = event_cfg->offload_channel;
698 		mhi_event++;
699 	}
700 
701 	return 0;
702 
703 error_ev_cfg:
704 
705 	kfree(mhi_cntrl->mhi_event);
706 	return -EINVAL;
707 }
708 
709 static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
710 			const struct mhi_controller_config *config)
711 {
712 	const struct mhi_channel_config *ch_cfg;
713 	struct device *dev = mhi_cntrl->cntrl_dev;
714 	int i;
715 	u32 chan;
716 
717 	mhi_cntrl->max_chan = config->max_channels;
718 
719 	/*
720 	 * The allocation of MHI channels can exceed 32KB in some scenarios,
721 	 * so to avoid any memory possible allocation failures, vzalloc is
722 	 * used here
723 	 */
724 	mhi_cntrl->mhi_chan = vzalloc(mhi_cntrl->max_chan *
725 				      sizeof(*mhi_cntrl->mhi_chan));
726 	if (!mhi_cntrl->mhi_chan)
727 		return -ENOMEM;
728 
729 	INIT_LIST_HEAD(&mhi_cntrl->lpm_chans);
730 
731 	/* Populate channel configurations */
732 	for (i = 0; i < config->num_channels; i++) {
733 		struct mhi_chan *mhi_chan;
734 
735 		ch_cfg = &config->ch_cfg[i];
736 
737 		chan = ch_cfg->num;
738 		if (chan >= mhi_cntrl->max_chan) {
739 			dev_err(dev, "Channel %d not available\n", chan);
740 			goto error_chan_cfg;
741 		}
742 
743 		mhi_chan = &mhi_cntrl->mhi_chan[chan];
744 		mhi_chan->name = ch_cfg->name;
745 		mhi_chan->chan = chan;
746 
747 		mhi_chan->tre_ring.elements = ch_cfg->num_elements;
748 		if (!mhi_chan->tre_ring.elements)
749 			goto error_chan_cfg;
750 
751 		/*
752 		 * For some channels, local ring length should be bigger than
753 		 * the transfer ring length due to internal logical channels
754 		 * in device. So host can queue much more buffers than transfer
755 		 * ring length. Example, RSC channels should have a larger local
756 		 * channel length than transfer ring length.
757 		 */
758 		mhi_chan->buf_ring.elements = ch_cfg->local_elements;
759 		if (!mhi_chan->buf_ring.elements)
760 			mhi_chan->buf_ring.elements = mhi_chan->tre_ring.elements;
761 		mhi_chan->er_index = ch_cfg->event_ring;
762 		mhi_chan->dir = ch_cfg->dir;
763 
764 		/*
765 		 * For most channels, chtype is identical to channel directions.
766 		 * So, if it is not defined then assign channel direction to
767 		 * chtype
768 		 */
769 		mhi_chan->type = ch_cfg->type;
770 		if (!mhi_chan->type)
771 			mhi_chan->type = (enum mhi_ch_type)mhi_chan->dir;
772 
773 		mhi_chan->ee_mask = ch_cfg->ee_mask;
774 		mhi_chan->db_cfg.pollcfg = ch_cfg->pollcfg;
775 		mhi_chan->lpm_notify = ch_cfg->lpm_notify;
776 		mhi_chan->offload_ch = ch_cfg->offload_channel;
777 		mhi_chan->db_cfg.reset_req = ch_cfg->doorbell_mode_switch;
778 		mhi_chan->pre_alloc = ch_cfg->auto_queue;
779 		mhi_chan->wake_capable = ch_cfg->wake_capable;
780 
781 		/*
782 		 * If MHI host allocates buffers, then the channel direction
783 		 * should be DMA_FROM_DEVICE
784 		 */
785 		if (mhi_chan->pre_alloc && mhi_chan->dir != DMA_FROM_DEVICE) {
786 			dev_err(dev, "Invalid channel configuration\n");
787 			goto error_chan_cfg;
788 		}
789 
790 		/*
791 		 * Bi-directional and direction less channel must be an
792 		 * offload channel
793 		 */
794 		if ((mhi_chan->dir == DMA_BIDIRECTIONAL ||
795 		     mhi_chan->dir == DMA_NONE) && !mhi_chan->offload_ch) {
796 			dev_err(dev, "Invalid channel configuration\n");
797 			goto error_chan_cfg;
798 		}
799 
800 		if (!mhi_chan->offload_ch) {
801 			mhi_chan->db_cfg.brstmode = ch_cfg->doorbell;
802 			if (MHI_INVALID_BRSTMODE(mhi_chan->db_cfg.brstmode)) {
803 				dev_err(dev, "Invalid Door bell mode\n");
804 				goto error_chan_cfg;
805 			}
806 		}
807 
808 		if (mhi_chan->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
809 			mhi_chan->db_cfg.process_db = mhi_db_brstmode;
810 		else
811 			mhi_chan->db_cfg.process_db = mhi_db_brstmode_disable;
812 
813 		mhi_chan->configured = true;
814 
815 		if (mhi_chan->lpm_notify)
816 			list_add_tail(&mhi_chan->node, &mhi_cntrl->lpm_chans);
817 	}
818 
819 	return 0;
820 
821 error_chan_cfg:
822 	vfree(mhi_cntrl->mhi_chan);
823 
824 	return -EINVAL;
825 }
826 
827 static int parse_config(struct mhi_controller *mhi_cntrl,
828 			const struct mhi_controller_config *config)
829 {
830 	int ret;
831 
832 	/* Parse MHI channel configuration */
833 	ret = parse_ch_cfg(mhi_cntrl, config);
834 	if (ret)
835 		return ret;
836 
837 	/* Parse MHI event configuration */
838 	ret = parse_ev_cfg(mhi_cntrl, config);
839 	if (ret)
840 		goto error_ev_cfg;
841 
842 	mhi_cntrl->timeout_ms = config->timeout_ms;
843 	if (!mhi_cntrl->timeout_ms)
844 		mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;
845 
846 	mhi_cntrl->bounce_buf = config->use_bounce_buf;
847 	mhi_cntrl->buffer_len = config->buf_len;
848 	if (!mhi_cntrl->buffer_len)
849 		mhi_cntrl->buffer_len = MHI_MAX_MTU;
850 
851 	/* By default, host is allowed to ring DB in both M0 and M2 states */
852 	mhi_cntrl->db_access = MHI_PM_M0 | MHI_PM_M2;
853 	if (config->m2_no_db)
854 		mhi_cntrl->db_access &= ~MHI_PM_M2;
855 
856 	return 0;
857 
858 error_ev_cfg:
859 	vfree(mhi_cntrl->mhi_chan);
860 
861 	return ret;
862 }
863 
864 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
865 			    const struct mhi_controller_config *config)
866 {
867 	struct mhi_event *mhi_event;
868 	struct mhi_chan *mhi_chan;
869 	struct mhi_cmd *mhi_cmd;
870 	struct mhi_device *mhi_dev;
871 	u32 soc_info;
872 	int ret, i;
873 
874 	if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->regs ||
875 	    !mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
876 	    !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
877 	    !mhi_cntrl->write_reg || !mhi_cntrl->nr_irqs ||
878 	    !mhi_cntrl->irq || !mhi_cntrl->reg_len)
879 		return -EINVAL;
880 
881 	ret = parse_config(mhi_cntrl, config);
882 	if (ret)
883 		return -EINVAL;
884 
885 	mhi_cntrl->mhi_cmd = kcalloc(NR_OF_CMD_RINGS,
886 				     sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
887 	if (!mhi_cntrl->mhi_cmd) {
888 		ret = -ENOMEM;
889 		goto err_free_event;
890 	}
891 
892 	INIT_LIST_HEAD(&mhi_cntrl->transition_list);
893 	mutex_init(&mhi_cntrl->pm_mutex);
894 	rwlock_init(&mhi_cntrl->pm_lock);
895 	spin_lock_init(&mhi_cntrl->transition_lock);
896 	spin_lock_init(&mhi_cntrl->wlock);
897 	INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
898 	init_waitqueue_head(&mhi_cntrl->state_event);
899 
900 	mhi_cntrl->hiprio_wq = alloc_ordered_workqueue("mhi_hiprio_wq", WQ_HIGHPRI);
901 	if (!mhi_cntrl->hiprio_wq) {
902 		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
903 		ret = -ENOMEM;
904 		goto err_free_cmd;
905 	}
906 
907 	mhi_cmd = mhi_cntrl->mhi_cmd;
908 	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
909 		spin_lock_init(&mhi_cmd->lock);
910 
911 	mhi_event = mhi_cntrl->mhi_event;
912 	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
913 		/* Skip for offload events */
914 		if (mhi_event->offload_ev)
915 			continue;
916 
917 		mhi_event->mhi_cntrl = mhi_cntrl;
918 		spin_lock_init(&mhi_event->lock);
919 		if (mhi_event->data_type == MHI_ER_CTRL)
920 			tasklet_init(&mhi_event->task, mhi_ctrl_ev_task,
921 				     (ulong)mhi_event);
922 		else
923 			tasklet_init(&mhi_event->task, mhi_ev_task,
924 				     (ulong)mhi_event);
925 	}
926 
927 	mhi_chan = mhi_cntrl->mhi_chan;
928 	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
929 		mutex_init(&mhi_chan->mutex);
930 		init_completion(&mhi_chan->completion);
931 		rwlock_init(&mhi_chan->lock);
932 
933 		/* used in setting bei field of TRE */
934 		mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
935 		mhi_chan->intmod = mhi_event->intmod;
936 	}
937 
938 	if (mhi_cntrl->bounce_buf) {
939 		mhi_cntrl->map_single = mhi_map_single_use_bb;
940 		mhi_cntrl->unmap_single = mhi_unmap_single_use_bb;
941 	} else {
942 		mhi_cntrl->map_single = mhi_map_single_no_bb;
943 		mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
944 	}
945 
946 	/* Read the MHI device info */
947 	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
948 			   SOC_HW_VERSION_OFFS, &soc_info);
949 	if (ret)
950 		goto err_destroy_wq;
951 
952 	mhi_cntrl->family_number = FIELD_GET(SOC_HW_VERSION_FAM_NUM_BMSK, soc_info);
953 	mhi_cntrl->device_number = FIELD_GET(SOC_HW_VERSION_DEV_NUM_BMSK, soc_info);
954 	mhi_cntrl->major_version = FIELD_GET(SOC_HW_VERSION_MAJOR_VER_BMSK, soc_info);
955 	mhi_cntrl->minor_version = FIELD_GET(SOC_HW_VERSION_MINOR_VER_BMSK, soc_info);
956 
957 	mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
958 	if (mhi_cntrl->index < 0) {
959 		ret = mhi_cntrl->index;
960 		goto err_destroy_wq;
961 	}
962 
963 	/* Register controller with MHI bus */
964 	mhi_dev = mhi_alloc_device(mhi_cntrl);
965 	if (IS_ERR(mhi_dev)) {
966 		dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n");
967 		ret = PTR_ERR(mhi_dev);
968 		goto err_ida_free;
969 	}
970 
971 	mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
972 	mhi_dev->mhi_cntrl = mhi_cntrl;
973 	dev_set_name(&mhi_dev->dev, "mhi%d", mhi_cntrl->index);
974 	mhi_dev->name = dev_name(&mhi_dev->dev);
975 
976 	/* Init wakeup source */
977 	device_init_wakeup(&mhi_dev->dev, true);
978 
979 	ret = device_add(&mhi_dev->dev);
980 	if (ret)
981 		goto err_release_dev;
982 
983 	mhi_cntrl->mhi_dev = mhi_dev;
984 
985 	mhi_create_debugfs(mhi_cntrl);
986 
987 	return 0;
988 
989 err_release_dev:
990 	put_device(&mhi_dev->dev);
991 err_ida_free:
992 	ida_free(&mhi_controller_ida, mhi_cntrl->index);
993 err_destroy_wq:
994 	destroy_workqueue(mhi_cntrl->hiprio_wq);
995 err_free_cmd:
996 	kfree(mhi_cntrl->mhi_cmd);
997 err_free_event:
998 	kfree(mhi_cntrl->mhi_event);
999 	vfree(mhi_cntrl->mhi_chan);
1000 
1001 	return ret;
1002 }
1003 EXPORT_SYMBOL_GPL(mhi_register_controller);
1004 
1005 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
1006 {
1007 	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
1008 	struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
1009 	unsigned int i;
1010 
1011 	mhi_destroy_debugfs(mhi_cntrl);
1012 
1013 	destroy_workqueue(mhi_cntrl->hiprio_wq);
1014 	kfree(mhi_cntrl->mhi_cmd);
1015 	kfree(mhi_cntrl->mhi_event);
1016 
1017 	/* Drop the references to MHI devices created for channels */
1018 	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
1019 		if (!mhi_chan->mhi_dev)
1020 			continue;
1021 
1022 		put_device(&mhi_chan->mhi_dev->dev);
1023 	}
1024 	vfree(mhi_cntrl->mhi_chan);
1025 
1026 	device_del(&mhi_dev->dev);
1027 	put_device(&mhi_dev->dev);
1028 
1029 	ida_free(&mhi_controller_ida, mhi_cntrl->index);
1030 }
1031 EXPORT_SYMBOL_GPL(mhi_unregister_controller);
1032 
1033 struct mhi_controller *mhi_alloc_controller(void)
1034 {
1035 	struct mhi_controller *mhi_cntrl;
1036 
1037 	mhi_cntrl = kzalloc(sizeof(*mhi_cntrl), GFP_KERNEL);
1038 
1039 	return mhi_cntrl;
1040 }
1041 EXPORT_SYMBOL_GPL(mhi_alloc_controller);
1042 
1043 void mhi_free_controller(struct mhi_controller *mhi_cntrl)
1044 {
1045 	kfree(mhi_cntrl);
1046 }
1047 EXPORT_SYMBOL_GPL(mhi_free_controller);
1048 
1049 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
1050 {
1051 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
1052 	u32 bhi_off, bhie_off;
1053 	int ret;
1054 
1055 	mutex_lock(&mhi_cntrl->pm_mutex);
1056 
1057 	ret = mhi_init_dev_ctxt(mhi_cntrl);
1058 	if (ret)
1059 		goto error_dev_ctxt;
1060 
1061 	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIOFF, &bhi_off);
1062 	if (ret) {
1063 		dev_err(dev, "Error getting BHI offset\n");
1064 		goto error_reg_offset;
1065 	}
1066 
1067 	if (bhi_off >= mhi_cntrl->reg_len) {
1068 		dev_err(dev, "BHI offset: 0x%x is out of range: 0x%zx\n",
1069 			bhi_off, mhi_cntrl->reg_len);
1070 		ret = -EINVAL;
1071 		goto error_reg_offset;
1072 	}
1073 	mhi_cntrl->bhi = mhi_cntrl->regs + bhi_off;
1074 
1075 	if (mhi_cntrl->fbc_download || mhi_cntrl->rddm_size) {
1076 		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF,
1077 				   &bhie_off);
1078 		if (ret) {
1079 			dev_err(dev, "Error getting BHIE offset\n");
1080 			goto error_reg_offset;
1081 		}
1082 
1083 		if (bhie_off >= mhi_cntrl->reg_len) {
1084 			dev_err(dev,
1085 				"BHIe offset: 0x%x is out of range: 0x%zx\n",
1086 				bhie_off, mhi_cntrl->reg_len);
1087 			ret = -EINVAL;
1088 			goto error_reg_offset;
1089 		}
1090 		mhi_cntrl->bhie = mhi_cntrl->regs + bhie_off;
1091 	}
1092 
1093 	if (mhi_cntrl->rddm_size) {
1094 		/*
1095 		 * This controller supports RDDM, so we need to manually clear
1096 		 * BHIE RX registers since POR values are undefined.
1097 		 */
1098 		memset_io(mhi_cntrl->bhie + BHIE_RXVECADDR_LOW_OFFS,
1099 			  0, BHIE_RXVECSTATUS_OFFS - BHIE_RXVECADDR_LOW_OFFS +
1100 			  4);
1101 		/*
1102 		 * Allocate RDDM table for debugging purpose if specified
1103 		 */
1104 		mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
1105 				     mhi_cntrl->rddm_size);
1106 		if (mhi_cntrl->rddm_image)
1107 			mhi_rddm_prepare(mhi_cntrl, mhi_cntrl->rddm_image);
1108 	}
1109 
1110 	mutex_unlock(&mhi_cntrl->pm_mutex);
1111 
1112 	return 0;
1113 
1114 error_reg_offset:
1115 	mhi_deinit_dev_ctxt(mhi_cntrl);
1116 
1117 error_dev_ctxt:
1118 	mutex_unlock(&mhi_cntrl->pm_mutex);
1119 
1120 	return ret;
1121 }
1122 EXPORT_SYMBOL_GPL(mhi_prepare_for_power_up);
1123 
1124 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
1125 {
1126 	if (mhi_cntrl->fbc_image) {
1127 		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
1128 		mhi_cntrl->fbc_image = NULL;
1129 	}
1130 
1131 	if (mhi_cntrl->rddm_image) {
1132 		mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
1133 		mhi_cntrl->rddm_image = NULL;
1134 	}
1135 
1136 	mhi_cntrl->bhi = NULL;
1137 	mhi_cntrl->bhie = NULL;
1138 
1139 	mhi_deinit_dev_ctxt(mhi_cntrl);
1140 }
1141 EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
1142 
1143 static void mhi_release_device(struct device *dev)
1144 {
1145 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1146 
1147 	/*
1148 	 * We need to set the mhi_chan->mhi_dev to NULL here since the MHI
1149 	 * devices for the channels will only get created if the mhi_dev
1150 	 * associated with it is NULL. This scenario will happen during the
1151 	 * controller suspend and resume.
1152 	 */
1153 	if (mhi_dev->ul_chan)
1154 		mhi_dev->ul_chan->mhi_dev = NULL;
1155 
1156 	if (mhi_dev->dl_chan)
1157 		mhi_dev->dl_chan->mhi_dev = NULL;
1158 
1159 	kfree(mhi_dev);
1160 }
1161 
1162 struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
1163 {
1164 	struct mhi_device *mhi_dev;
1165 	struct device *dev;
1166 
1167 	mhi_dev = kzalloc(sizeof(*mhi_dev), GFP_KERNEL);
1168 	if (!mhi_dev)
1169 		return ERR_PTR(-ENOMEM);
1170 
1171 	dev = &mhi_dev->dev;
1172 	device_initialize(dev);
1173 	dev->bus = &mhi_bus_type;
1174 	dev->release = mhi_release_device;
1175 
1176 	if (mhi_cntrl->mhi_dev) {
1177 		/* for MHI client devices, parent is the MHI controller device */
1178 		dev->parent = &mhi_cntrl->mhi_dev->dev;
1179 	} else {
1180 		/* for MHI controller device, parent is the bus device (e.g. pci device) */
1181 		dev->parent = mhi_cntrl->cntrl_dev;
1182 	}
1183 
1184 	mhi_dev->mhi_cntrl = mhi_cntrl;
1185 	mhi_dev->dev_wake = 0;
1186 
1187 	return mhi_dev;
1188 }
1189 
1190 static int mhi_driver_probe(struct device *dev)
1191 {
1192 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1193 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1194 	struct device_driver *drv = dev->driver;
1195 	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1196 	struct mhi_event *mhi_event;
1197 	struct mhi_chan *ul_chan = mhi_dev->ul_chan;
1198 	struct mhi_chan *dl_chan = mhi_dev->dl_chan;
1199 	int ret;
1200 
1201 	/* Bring device out of LPM */
1202 	ret = mhi_device_get_sync(mhi_dev);
1203 	if (ret)
1204 		return ret;
1205 
1206 	ret = -EINVAL;
1207 
1208 	if (ul_chan) {
1209 		/*
1210 		 * If channel supports LPM notifications then status_cb should
1211 		 * be provided
1212 		 */
1213 		if (ul_chan->lpm_notify && !mhi_drv->status_cb)
1214 			goto exit_probe;
1215 
1216 		/* For non-offload channels then xfer_cb should be provided */
1217 		if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb)
1218 			goto exit_probe;
1219 
1220 		ul_chan->xfer_cb = mhi_drv->ul_xfer_cb;
1221 	}
1222 
1223 	ret = -EINVAL;
1224 	if (dl_chan) {
1225 		/*
1226 		 * If channel supports LPM notifications then status_cb should
1227 		 * be provided
1228 		 */
1229 		if (dl_chan->lpm_notify && !mhi_drv->status_cb)
1230 			goto exit_probe;
1231 
1232 		/* For non-offload channels then xfer_cb should be provided */
1233 		if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb)
1234 			goto exit_probe;
1235 
1236 		mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index];
1237 
1238 		/*
1239 		 * If the channel event ring is managed by client, then
1240 		 * status_cb must be provided so that the framework can
1241 		 * notify pending data
1242 		 */
1243 		if (mhi_event->cl_manage && !mhi_drv->status_cb)
1244 			goto exit_probe;
1245 
1246 		dl_chan->xfer_cb = mhi_drv->dl_xfer_cb;
1247 	}
1248 
1249 	/* Call the user provided probe function */
1250 	ret = mhi_drv->probe(mhi_dev, mhi_dev->id);
1251 	if (ret)
1252 		goto exit_probe;
1253 
1254 	mhi_device_put(mhi_dev);
1255 
1256 	return ret;
1257 
1258 exit_probe:
1259 	mhi_unprepare_from_transfer(mhi_dev);
1260 
1261 	mhi_device_put(mhi_dev);
1262 
1263 	return ret;
1264 }
1265 
1266 static int mhi_driver_remove(struct device *dev)
1267 {
1268 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1269 	struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver);
1270 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1271 	struct mhi_chan *mhi_chan;
1272 	enum mhi_ch_state ch_state[] = {
1273 		MHI_CH_STATE_DISABLED,
1274 		MHI_CH_STATE_DISABLED
1275 	};
1276 	int dir;
1277 
1278 	/* Skip if it is a controller device */
1279 	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1280 		return 0;
1281 
1282 	/* Reset both channels */
1283 	for (dir = 0; dir < 2; dir++) {
1284 		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1285 
1286 		if (!mhi_chan)
1287 			continue;
1288 
1289 		/* Wake all threads waiting for completion */
1290 		write_lock_irq(&mhi_chan->lock);
1291 		mhi_chan->ccs = MHI_EV_CC_INVALID;
1292 		complete_all(&mhi_chan->completion);
1293 		write_unlock_irq(&mhi_chan->lock);
1294 
1295 		/* Set the channel state to disabled */
1296 		mutex_lock(&mhi_chan->mutex);
1297 		write_lock_irq(&mhi_chan->lock);
1298 		ch_state[dir] = mhi_chan->ch_state;
1299 		mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED;
1300 		write_unlock_irq(&mhi_chan->lock);
1301 
1302 		/* Reset the non-offload channel */
1303 		if (!mhi_chan->offload_ch)
1304 			mhi_reset_chan(mhi_cntrl, mhi_chan);
1305 
1306 		mutex_unlock(&mhi_chan->mutex);
1307 	}
1308 
1309 	mhi_drv->remove(mhi_dev);
1310 
1311 	/* De-init channel if it was enabled */
1312 	for (dir = 0; dir < 2; dir++) {
1313 		mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1314 
1315 		if (!mhi_chan)
1316 			continue;
1317 
1318 		mutex_lock(&mhi_chan->mutex);
1319 
1320 		if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
1321 		     ch_state[dir] == MHI_CH_STATE_STOP) &&
1322 		    !mhi_chan->offload_ch)
1323 			mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
1324 
1325 		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
1326 
1327 		mutex_unlock(&mhi_chan->mutex);
1328 	}
1329 
1330 	while (mhi_dev->dev_wake)
1331 		mhi_device_put(mhi_dev);
1332 
1333 	return 0;
1334 }
1335 
1336 int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner)
1337 {
1338 	struct device_driver *driver = &mhi_drv->driver;
1339 
1340 	if (!mhi_drv->probe || !mhi_drv->remove)
1341 		return -EINVAL;
1342 
1343 	driver->bus = &mhi_bus_type;
1344 	driver->owner = owner;
1345 	driver->probe = mhi_driver_probe;
1346 	driver->remove = mhi_driver_remove;
1347 
1348 	return driver_register(driver);
1349 }
1350 EXPORT_SYMBOL_GPL(__mhi_driver_register);
1351 
1352 void mhi_driver_unregister(struct mhi_driver *mhi_drv)
1353 {
1354 	driver_unregister(&mhi_drv->driver);
1355 }
1356 EXPORT_SYMBOL_GPL(mhi_driver_unregister);
1357 
1358 static int mhi_uevent(struct device *dev, struct kobj_uevent_env *env)
1359 {
1360 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1361 
1362 	return add_uevent_var(env, "MODALIAS=" MHI_DEVICE_MODALIAS_FMT,
1363 					mhi_dev->name);
1364 }
1365 
1366 static int mhi_match(struct device *dev, struct device_driver *drv)
1367 {
1368 	struct mhi_device *mhi_dev = to_mhi_device(dev);
1369 	struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1370 	const struct mhi_device_id *id;
1371 
1372 	/*
1373 	 * If the device is a controller type then there is no client driver
1374 	 * associated with it
1375 	 */
1376 	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1377 		return 0;
1378 
1379 	for (id = mhi_drv->id_table; id->chan[0]; id++)
1380 		if (!strcmp(mhi_dev->name, id->chan)) {
1381 			mhi_dev->id = id;
1382 			return 1;
1383 		}
1384 
1385 	return 0;
1386 };
1387 
1388 struct bus_type mhi_bus_type = {
1389 	.name = "mhi",
1390 	.dev_name = "mhi",
1391 	.match = mhi_match,
1392 	.uevent = mhi_uevent,
1393 	.dev_groups = mhi_dev_groups,
1394 };
1395 
1396 static int __init mhi_init(void)
1397 {
1398 	mhi_debugfs_init();
1399 	return bus_register(&mhi_bus_type);
1400 }
1401 
1402 static void __exit mhi_exit(void)
1403 {
1404 	mhi_debugfs_exit();
1405 	bus_unregister(&mhi_bus_type);
1406 }
1407 
1408 postcore_initcall(mhi_init);
1409 module_exit(mhi_exit);
1410 
1411 MODULE_LICENSE("GPL v2");
1412 MODULE_DESCRIPTION("MHI Host Interface");
1413