xref: /kernel/linux/linux-5.10/drivers/bus/mhi/host/pm.c (revision 8c2ecf20)
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/delay.h>
8#include <linux/device.h>
9#include <linux/dma-direction.h>
10#include <linux/dma-mapping.h>
11#include <linux/interrupt.h>
12#include <linux/list.h>
13#include <linux/mhi.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/wait.h>
17#include "internal.h"
18
19/*
20 * Not all MHI state transitions are synchronous. Transitions like Linkdown,
21 * SYS_ERR, and shutdown can happen anytime asynchronously. This function will
22 * transition to a new state only if we're allowed to.
23 *
24 * Priority increases as we go down. For instance, from any state in L0, the
25 * transition can be made to states in L1, L2 and L3. A notable exception to
26 * this rule is state DISABLE.  From DISABLE state we can only transition to
27 * POR state. Also, while in L2 state, user cannot jump back to previous
28 * L1 or L0 states.
29 *
30 * Valid transitions:
31 * L0: DISABLE <--> POR
32 *     POR <--> POR
33 *     POR -> M0 -> M2 --> M0
34 *     POR -> FW_DL_ERR
35 *     FW_DL_ERR <--> FW_DL_ERR
36 *     M0 <--> M0
37 *     M0 -> FW_DL_ERR
38 *     M0 -> M3_ENTER -> M3 -> M3_EXIT --> M0
39 * L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS --> POR
40 * L2: SHUTDOWN_PROCESS -> DISABLE
41 * L3: LD_ERR_FATAL_DETECT <--> LD_ERR_FATAL_DETECT
42 *     LD_ERR_FATAL_DETECT -> SHUTDOWN_PROCESS
43 */
44static struct mhi_pm_transitions const dev_state_transitions[] = {
45	/* L0 States */
46	{
47		MHI_PM_DISABLE,
48		MHI_PM_POR
49	},
50	{
51		MHI_PM_POR,
52		MHI_PM_POR | MHI_PM_DISABLE | MHI_PM_M0 |
53		MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
54		MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR
55	},
56	{
57		MHI_PM_M0,
58		MHI_PM_M0 | MHI_PM_M2 | MHI_PM_M3_ENTER |
59		MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
60		MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR
61	},
62	{
63		MHI_PM_M2,
64		MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
65		MHI_PM_LD_ERR_FATAL_DETECT
66	},
67	{
68		MHI_PM_M3_ENTER,
69		MHI_PM_M3 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
70		MHI_PM_LD_ERR_FATAL_DETECT
71	},
72	{
73		MHI_PM_M3,
74		MHI_PM_M3_EXIT | MHI_PM_SYS_ERR_DETECT |
75		MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT
76	},
77	{
78		MHI_PM_M3_EXIT,
79		MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
80		MHI_PM_LD_ERR_FATAL_DETECT
81	},
82	{
83		MHI_PM_FW_DL_ERR,
84		MHI_PM_FW_DL_ERR | MHI_PM_SYS_ERR_DETECT |
85		MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT
86	},
87	/* L1 States */
88	{
89		MHI_PM_SYS_ERR_DETECT,
90		MHI_PM_SYS_ERR_PROCESS | MHI_PM_SHUTDOWN_PROCESS |
91		MHI_PM_LD_ERR_FATAL_DETECT
92	},
93	{
94		MHI_PM_SYS_ERR_PROCESS,
95		MHI_PM_POR | MHI_PM_SHUTDOWN_PROCESS |
96		MHI_PM_LD_ERR_FATAL_DETECT
97	},
98	/* L2 States */
99	{
100		MHI_PM_SHUTDOWN_PROCESS,
101		MHI_PM_DISABLE | MHI_PM_LD_ERR_FATAL_DETECT
102	},
103	/* L3 States */
104	{
105		MHI_PM_LD_ERR_FATAL_DETECT,
106		MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_SHUTDOWN_PROCESS
107	},
108};
109
110enum mhi_pm_state __must_check mhi_tryset_pm_state(struct mhi_controller *mhi_cntrl,
111						   enum mhi_pm_state state)
112{
113	unsigned long cur_state = mhi_cntrl->pm_state;
114	int index = find_last_bit(&cur_state, 32);
115
116	if (unlikely(index >= ARRAY_SIZE(dev_state_transitions)))
117		return cur_state;
118
119	if (unlikely(dev_state_transitions[index].from_state != cur_state))
120		return cur_state;
121
122	if (unlikely(!(dev_state_transitions[index].to_states & state)))
123		return cur_state;
124
125	mhi_cntrl->pm_state = state;
126	return mhi_cntrl->pm_state;
127}
128
129void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, enum mhi_state state)
130{
131	if (state == MHI_STATE_RESET) {
132		mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
133				    MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 1);
134	} else {
135		mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
136				    MHICTRL_MHISTATE_MASK,
137				    MHICTRL_MHISTATE_SHIFT, state);
138	}
139}
140
141/* NOP for backward compatibility, host allowed to ring DB in M2 state */
142static void mhi_toggle_dev_wake_nop(struct mhi_controller *mhi_cntrl)
143{
144}
145
146static void mhi_toggle_dev_wake(struct mhi_controller *mhi_cntrl)
147{
148	mhi_cntrl->wake_get(mhi_cntrl, false);
149	mhi_cntrl->wake_put(mhi_cntrl, true);
150}
151
152/* Handle device ready state transition */
153int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
154{
155	void __iomem *base = mhi_cntrl->regs;
156	struct mhi_event *mhi_event;
157	enum mhi_pm_state cur_state;
158	struct device *dev = &mhi_cntrl->mhi_dev->dev;
159	u32 reset = 1, ready = 0;
160	int ret, i;
161
162	/* Wait for RESET to be cleared and READY bit to be set by the device */
163	wait_event_timeout(mhi_cntrl->state_event,
164			   MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) ||
165			   mhi_read_reg_field(mhi_cntrl, base, MHICTRL,
166					      MHICTRL_RESET_MASK,
167					      MHICTRL_RESET_SHIFT, &reset) ||
168			   mhi_read_reg_field(mhi_cntrl, base, MHISTATUS,
169					      MHISTATUS_READY_MASK,
170					      MHISTATUS_READY_SHIFT, &ready) ||
171			   (!reset && ready),
172			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
173
174	/* Check if device entered error state */
175	if (MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) {
176		dev_err(dev, "Device link is not accessible\n");
177		return -EIO;
178	}
179
180	/* Timeout if device did not transition to ready state */
181	if (reset || !ready) {
182		dev_err(dev, "Device Ready timeout\n");
183		return -ETIMEDOUT;
184	}
185
186	dev_dbg(dev, "Device in READY State\n");
187	write_lock_irq(&mhi_cntrl->pm_lock);
188	cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_POR);
189	mhi_cntrl->dev_state = MHI_STATE_READY;
190	write_unlock_irq(&mhi_cntrl->pm_lock);
191
192	if (cur_state != MHI_PM_POR) {
193		dev_err(dev, "Error moving to state %s from %s\n",
194			to_mhi_pm_state_str(MHI_PM_POR),
195			to_mhi_pm_state_str(cur_state));
196		return -EIO;
197	}
198
199	read_lock_bh(&mhi_cntrl->pm_lock);
200	if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
201		dev_err(dev, "Device registers not accessible\n");
202		goto error_mmio;
203	}
204
205	/* Configure MMIO registers */
206	ret = mhi_init_mmio(mhi_cntrl);
207	if (ret) {
208		dev_err(dev, "Error configuring MMIO registers\n");
209		goto error_mmio;
210	}
211
212	/* Add elements to all SW event rings */
213	mhi_event = mhi_cntrl->mhi_event;
214	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
215		struct mhi_ring *ring = &mhi_event->ring;
216
217		/* Skip if this is an offload or HW event */
218		if (mhi_event->offload_ev || mhi_event->hw_ring)
219			continue;
220
221		ring->wp = ring->base + ring->len - ring->el_size;
222		*ring->ctxt_wp = ring->iommu_base + ring->len - ring->el_size;
223		/* Update all cores */
224		smp_wmb();
225
226		/* Ring the event ring db */
227		spin_lock_irq(&mhi_event->lock);
228		mhi_ring_er_db(mhi_event);
229		spin_unlock_irq(&mhi_event->lock);
230	}
231
232	/* Set MHI to M0 state */
233	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M0);
234	read_unlock_bh(&mhi_cntrl->pm_lock);
235
236	return 0;
237
238error_mmio:
239	read_unlock_bh(&mhi_cntrl->pm_lock);
240
241	return -EIO;
242}
243
244int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl)
245{
246	enum mhi_pm_state cur_state;
247	struct mhi_chan *mhi_chan;
248	struct device *dev = &mhi_cntrl->mhi_dev->dev;
249	int i;
250
251	write_lock_irq(&mhi_cntrl->pm_lock);
252	mhi_cntrl->dev_state = MHI_STATE_M0;
253	cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M0);
254	write_unlock_irq(&mhi_cntrl->pm_lock);
255	if (unlikely(cur_state != MHI_PM_M0)) {
256		dev_err(dev, "Unable to transition to M0 state\n");
257		return -EIO;
258	}
259	mhi_cntrl->M0++;
260
261	/* Wake up the device */
262	read_lock_bh(&mhi_cntrl->pm_lock);
263	mhi_cntrl->wake_get(mhi_cntrl, true);
264
265	/* Ring all event rings and CMD ring only if we're in mission mode */
266	if (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) {
267		struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
268		struct mhi_cmd *mhi_cmd =
269			&mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
270
271		for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
272			if (mhi_event->offload_ev)
273				continue;
274
275			spin_lock_irq(&mhi_event->lock);
276			mhi_ring_er_db(mhi_event);
277			spin_unlock_irq(&mhi_event->lock);
278		}
279
280		/* Only ring primary cmd ring if ring is not empty */
281		spin_lock_irq(&mhi_cmd->lock);
282		if (mhi_cmd->ring.rp != mhi_cmd->ring.wp)
283			mhi_ring_cmd_db(mhi_cntrl, mhi_cmd);
284		spin_unlock_irq(&mhi_cmd->lock);
285	}
286
287	/* Ring channel DB registers */
288	mhi_chan = mhi_cntrl->mhi_chan;
289	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
290		struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
291
292		if (mhi_chan->db_cfg.reset_req) {
293			write_lock_irq(&mhi_chan->lock);
294			mhi_chan->db_cfg.db_mode = true;
295			write_unlock_irq(&mhi_chan->lock);
296		}
297
298		read_lock_irq(&mhi_chan->lock);
299
300		/* Only ring DB if ring is not empty */
301		if (tre_ring->base && tre_ring->wp  != tre_ring->rp &&
302		    mhi_chan->ch_state == MHI_CH_STATE_ENABLED)
303			mhi_ring_chan_db(mhi_cntrl, mhi_chan);
304		read_unlock_irq(&mhi_chan->lock);
305	}
306
307	mhi_cntrl->wake_put(mhi_cntrl, false);
308	read_unlock_bh(&mhi_cntrl->pm_lock);
309	wake_up_all(&mhi_cntrl->state_event);
310
311	return 0;
312}
313
314/*
315 * After receiving the MHI state change event from the device indicating the
316 * transition to M1 state, the host can transition the device to M2 state
317 * for keeping it in low power state.
318 */
319void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl)
320{
321	enum mhi_pm_state state;
322	struct device *dev = &mhi_cntrl->mhi_dev->dev;
323
324	write_lock_irq(&mhi_cntrl->pm_lock);
325	state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M2);
326	if (state == MHI_PM_M2) {
327		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M2);
328		mhi_cntrl->dev_state = MHI_STATE_M2;
329
330		write_unlock_irq(&mhi_cntrl->pm_lock);
331
332		mhi_cntrl->M2++;
333		wake_up_all(&mhi_cntrl->state_event);
334
335		/* If there are any pending resources, exit M2 immediately */
336		if (unlikely(atomic_read(&mhi_cntrl->pending_pkts) ||
337			     atomic_read(&mhi_cntrl->dev_wake))) {
338			dev_dbg(dev,
339				"Exiting M2, pending_pkts: %d dev_wake: %d\n",
340				atomic_read(&mhi_cntrl->pending_pkts),
341				atomic_read(&mhi_cntrl->dev_wake));
342			read_lock_bh(&mhi_cntrl->pm_lock);
343			mhi_cntrl->wake_get(mhi_cntrl, true);
344			mhi_cntrl->wake_put(mhi_cntrl, true);
345			read_unlock_bh(&mhi_cntrl->pm_lock);
346		} else {
347			mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_IDLE);
348		}
349	} else {
350		write_unlock_irq(&mhi_cntrl->pm_lock);
351	}
352}
353
354/* MHI M3 completion handler */
355int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl)
356{
357	enum mhi_pm_state state;
358	struct device *dev = &mhi_cntrl->mhi_dev->dev;
359
360	write_lock_irq(&mhi_cntrl->pm_lock);
361	mhi_cntrl->dev_state = MHI_STATE_M3;
362	state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3);
363	write_unlock_irq(&mhi_cntrl->pm_lock);
364	if (state != MHI_PM_M3) {
365		dev_err(dev, "Unable to transition to M3 state\n");
366		return -EIO;
367	}
368
369	mhi_cntrl->M3++;
370	wake_up_all(&mhi_cntrl->state_event);
371
372	return 0;
373}
374
375/* Handle device Mission Mode transition */
376static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
377{
378	struct mhi_event *mhi_event;
379	struct device *dev = &mhi_cntrl->mhi_dev->dev;
380	enum mhi_ee_type current_ee = mhi_cntrl->ee;
381	int i, ret;
382
383	dev_dbg(dev, "Processing Mission Mode transition\n");
384
385	write_lock_irq(&mhi_cntrl->pm_lock);
386	if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))
387		mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
388	write_unlock_irq(&mhi_cntrl->pm_lock);
389
390	if (!MHI_IN_MISSION_MODE(mhi_cntrl->ee))
391		return -EIO;
392
393	wake_up_all(&mhi_cntrl->state_event);
394
395	device_for_each_child(&mhi_cntrl->mhi_dev->dev, &current_ee,
396			      mhi_destroy_device);
397	mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_MISSION_MODE);
398
399	/* Force MHI to be in M0 state before continuing */
400	ret = __mhi_device_get_sync(mhi_cntrl);
401	if (ret)
402		return ret;
403
404	read_lock_bh(&mhi_cntrl->pm_lock);
405
406	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
407		ret = -EIO;
408		goto error_mission_mode;
409	}
410
411	/* Add elements to all HW event rings */
412	mhi_event = mhi_cntrl->mhi_event;
413	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
414		struct mhi_ring *ring = &mhi_event->ring;
415
416		if (mhi_event->offload_ev || !mhi_event->hw_ring)
417			continue;
418
419		ring->wp = ring->base + ring->len - ring->el_size;
420		*ring->ctxt_wp = ring->iommu_base + ring->len - ring->el_size;
421		/* Update to all cores */
422		smp_wmb();
423
424		spin_lock_irq(&mhi_event->lock);
425		if (MHI_DB_ACCESS_VALID(mhi_cntrl))
426			mhi_ring_er_db(mhi_event);
427		spin_unlock_irq(&mhi_event->lock);
428	}
429
430	read_unlock_bh(&mhi_cntrl->pm_lock);
431
432	/*
433	 * The MHI devices are only created when the client device switches its
434	 * Execution Environment (EE) to either SBL or AMSS states
435	 */
436	mhi_create_devices(mhi_cntrl);
437
438	read_lock_bh(&mhi_cntrl->pm_lock);
439
440error_mission_mode:
441	mhi_cntrl->wake_put(mhi_cntrl, false);
442	read_unlock_bh(&mhi_cntrl->pm_lock);
443
444	return ret;
445}
446
447/* Handle SYS_ERR and Shutdown transitions */
448static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
449				      enum mhi_pm_state transition_state)
450{
451	enum mhi_pm_state cur_state, prev_state;
452	struct mhi_event *mhi_event;
453	struct mhi_cmd_ctxt *cmd_ctxt;
454	struct mhi_cmd *mhi_cmd;
455	struct mhi_event_ctxt *er_ctxt;
456	struct device *dev = &mhi_cntrl->mhi_dev->dev;
457	int ret, i;
458
459	dev_dbg(dev, "Transitioning from PM state: %s to: %s\n",
460		to_mhi_pm_state_str(mhi_cntrl->pm_state),
461		to_mhi_pm_state_str(transition_state));
462
463	/* We must notify MHI control driver so it can clean up first */
464	if (transition_state == MHI_PM_SYS_ERR_PROCESS)
465		mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR);
466
467	mutex_lock(&mhi_cntrl->pm_mutex);
468	write_lock_irq(&mhi_cntrl->pm_lock);
469	prev_state = mhi_cntrl->pm_state;
470	cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state);
471	if (cur_state == transition_state) {
472		mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION;
473		mhi_cntrl->dev_state = MHI_STATE_RESET;
474	}
475	write_unlock_irq(&mhi_cntrl->pm_lock);
476
477	/* Wake up threads waiting for state transition */
478	wake_up_all(&mhi_cntrl->state_event);
479
480	if (cur_state != transition_state) {
481		dev_err(dev, "Failed to transition to state: %s from: %s\n",
482			to_mhi_pm_state_str(transition_state),
483			to_mhi_pm_state_str(cur_state));
484		mutex_unlock(&mhi_cntrl->pm_mutex);
485		return;
486	}
487
488	/* Trigger MHI RESET so that the device will not access host memory */
489	if (MHI_REG_ACCESS_VALID(prev_state)) {
490		u32 in_reset = -1;
491		unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms);
492
493		/* Skip MHI RESET if in RDDM state */
494		if (mhi_cntrl->rddm_image && mhi_get_exec_env(mhi_cntrl) == MHI_EE_RDDM)
495			goto skip_mhi_reset;
496
497		dev_dbg(dev, "Triggering MHI Reset in device\n");
498		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
499
500		/* Wait for the reset bit to be cleared by the device */
501		ret = wait_event_timeout(mhi_cntrl->state_event,
502					 mhi_read_reg_field(mhi_cntrl,
503							    mhi_cntrl->regs,
504							    MHICTRL,
505							    MHICTRL_RESET_MASK,
506							    MHICTRL_RESET_SHIFT,
507							    &in_reset) ||
508					!in_reset, timeout);
509		if ((!ret || in_reset) && cur_state == MHI_PM_SYS_ERR_PROCESS) {
510			dev_err(dev, "Device failed to exit MHI Reset state\n");
511			mutex_unlock(&mhi_cntrl->pm_mutex);
512			return;
513		}
514
515		/*
516		 * Device will clear BHI_INTVEC as a part of RESET processing,
517		 * hence re-program it
518		 */
519		mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
520	}
521
522skip_mhi_reset:
523	dev_dbg(dev,
524		 "Waiting for all pending event ring processing to complete\n");
525	mhi_event = mhi_cntrl->mhi_event;
526	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
527		if (mhi_event->offload_ev)
528			continue;
529		tasklet_kill(&mhi_event->task);
530	}
531
532	/* Release lock and wait for all pending threads to complete */
533	mutex_unlock(&mhi_cntrl->pm_mutex);
534	dev_dbg(dev, "Waiting for all pending threads to complete\n");
535	wake_up_all(&mhi_cntrl->state_event);
536
537	dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
538	device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device);
539
540	mutex_lock(&mhi_cntrl->pm_mutex);
541
542	WARN_ON(atomic_read(&mhi_cntrl->dev_wake));
543	WARN_ON(atomic_read(&mhi_cntrl->pending_pkts));
544
545	/* Reset the ev rings and cmd rings */
546	dev_dbg(dev, "Resetting EV CTXT and CMD CTXT\n");
547	mhi_cmd = mhi_cntrl->mhi_cmd;
548	cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt;
549	for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
550		struct mhi_ring *ring = &mhi_cmd->ring;
551
552		ring->rp = ring->base;
553		ring->wp = ring->base;
554		cmd_ctxt->rp = cmd_ctxt->rbase;
555		cmd_ctxt->wp = cmd_ctxt->rbase;
556	}
557
558	mhi_event = mhi_cntrl->mhi_event;
559	er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
560	for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
561		     mhi_event++) {
562		struct mhi_ring *ring = &mhi_event->ring;
563
564		/* Skip offload events */
565		if (mhi_event->offload_ev)
566			continue;
567
568		ring->rp = ring->base;
569		ring->wp = ring->base;
570		er_ctxt->rp = er_ctxt->rbase;
571		er_ctxt->wp = er_ctxt->rbase;
572	}
573
574	if (cur_state == MHI_PM_SYS_ERR_PROCESS) {
575		mhi_ready_state_transition(mhi_cntrl);
576	} else {
577		/* Move to disable state */
578		write_lock_irq(&mhi_cntrl->pm_lock);
579		cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE);
580		write_unlock_irq(&mhi_cntrl->pm_lock);
581		if (unlikely(cur_state != MHI_PM_DISABLE))
582			dev_err(dev, "Error moving from PM state: %s to: %s\n",
583				to_mhi_pm_state_str(cur_state),
584				to_mhi_pm_state_str(MHI_PM_DISABLE));
585	}
586
587	dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
588		to_mhi_pm_state_str(mhi_cntrl->pm_state),
589		TO_MHI_STATE_STR(mhi_cntrl->dev_state));
590
591	mutex_unlock(&mhi_cntrl->pm_mutex);
592}
593
594/* Queue a new work item and schedule work */
595int mhi_queue_state_transition(struct mhi_controller *mhi_cntrl,
596			       enum dev_st_transition state)
597{
598	struct state_transition *item = kmalloc(sizeof(*item), GFP_ATOMIC);
599	unsigned long flags;
600
601	if (!item)
602		return -ENOMEM;
603
604	item->state = state;
605	spin_lock_irqsave(&mhi_cntrl->transition_lock, flags);
606	list_add_tail(&item->node, &mhi_cntrl->transition_list);
607	spin_unlock_irqrestore(&mhi_cntrl->transition_lock, flags);
608
609	schedule_work(&mhi_cntrl->st_worker);
610
611	return 0;
612}
613
614/* SYS_ERR worker */
615void mhi_pm_sys_err_handler(struct mhi_controller *mhi_cntrl)
616{
617	struct device *dev = &mhi_cntrl->mhi_dev->dev;
618
619	/* skip if controller supports RDDM */
620	if (mhi_cntrl->rddm_image) {
621		dev_dbg(dev, "Controller supports RDDM, skip SYS_ERROR\n");
622		return;
623	}
624
625	mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_SYS_ERR);
626}
627
628/* Device State Transition worker */
629void mhi_pm_st_worker(struct work_struct *work)
630{
631	struct state_transition *itr, *tmp;
632	LIST_HEAD(head);
633	struct mhi_controller *mhi_cntrl = container_of(work,
634							struct mhi_controller,
635							st_worker);
636	struct device *dev = &mhi_cntrl->mhi_dev->dev;
637
638	spin_lock_irq(&mhi_cntrl->transition_lock);
639	list_splice_tail_init(&mhi_cntrl->transition_list, &head);
640	spin_unlock_irq(&mhi_cntrl->transition_lock);
641
642	list_for_each_entry_safe(itr, tmp, &head, node) {
643		list_del(&itr->node);
644		dev_dbg(dev, "Handling state transition: %s\n",
645			TO_DEV_STATE_TRANS_STR(itr->state));
646
647		switch (itr->state) {
648		case DEV_ST_TRANSITION_PBL:
649			write_lock_irq(&mhi_cntrl->pm_lock);
650			if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))
651				mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
652			write_unlock_irq(&mhi_cntrl->pm_lock);
653			if (MHI_IN_PBL(mhi_cntrl->ee))
654				mhi_fw_load_handler(mhi_cntrl);
655			break;
656		case DEV_ST_TRANSITION_SBL:
657			write_lock_irq(&mhi_cntrl->pm_lock);
658			mhi_cntrl->ee = MHI_EE_SBL;
659			write_unlock_irq(&mhi_cntrl->pm_lock);
660			/*
661			 * The MHI devices are only created when the client
662			 * device switches its Execution Environment (EE) to
663			 * either SBL or AMSS states
664			 */
665			mhi_create_devices(mhi_cntrl);
666			break;
667		case DEV_ST_TRANSITION_MISSION_MODE:
668			mhi_pm_mission_mode_transition(mhi_cntrl);
669			break;
670		case DEV_ST_TRANSITION_READY:
671			mhi_ready_state_transition(mhi_cntrl);
672			break;
673		case DEV_ST_TRANSITION_SYS_ERR:
674			mhi_pm_disable_transition
675				(mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
676			break;
677		case DEV_ST_TRANSITION_DISABLE:
678			mhi_pm_disable_transition
679				(mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS);
680			break;
681		default:
682			break;
683		}
684		kfree(itr);
685	}
686}
687
688int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
689{
690	struct mhi_chan *itr, *tmp;
691	struct device *dev = &mhi_cntrl->mhi_dev->dev;
692	enum mhi_pm_state new_state;
693	int ret;
694
695	if (mhi_cntrl->pm_state == MHI_PM_DISABLE)
696		return -EINVAL;
697
698	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))
699		return -EIO;
700
701	/* Return busy if there are any pending resources */
702	if (atomic_read(&mhi_cntrl->dev_wake) ||
703	    atomic_read(&mhi_cntrl->pending_pkts))
704		return -EBUSY;
705
706	/* Take MHI out of M2 state */
707	read_lock_bh(&mhi_cntrl->pm_lock);
708	mhi_cntrl->wake_get(mhi_cntrl, false);
709	read_unlock_bh(&mhi_cntrl->pm_lock);
710
711	ret = wait_event_timeout(mhi_cntrl->state_event,
712				 mhi_cntrl->dev_state == MHI_STATE_M0 ||
713				 mhi_cntrl->dev_state == MHI_STATE_M1 ||
714				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
715				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
716
717	read_lock_bh(&mhi_cntrl->pm_lock);
718	mhi_cntrl->wake_put(mhi_cntrl, false);
719	read_unlock_bh(&mhi_cntrl->pm_lock);
720
721	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
722		dev_err(dev,
723			"Could not enter M0/M1 state");
724		return -EIO;
725	}
726
727	write_lock_irq(&mhi_cntrl->pm_lock);
728
729	if (atomic_read(&mhi_cntrl->dev_wake) ||
730	    atomic_read(&mhi_cntrl->pending_pkts)) {
731		write_unlock_irq(&mhi_cntrl->pm_lock);
732		return -EBUSY;
733	}
734
735	dev_info(dev, "Allowing M3 transition\n");
736	new_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_ENTER);
737	if (new_state != MHI_PM_M3_ENTER) {
738		write_unlock_irq(&mhi_cntrl->pm_lock);
739		dev_err(dev,
740			"Error setting to PM state: %s from: %s\n",
741			to_mhi_pm_state_str(MHI_PM_M3_ENTER),
742			to_mhi_pm_state_str(mhi_cntrl->pm_state));
743		return -EIO;
744	}
745
746	/* Set MHI to M3 and wait for completion */
747	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M3);
748	write_unlock_irq(&mhi_cntrl->pm_lock);
749	dev_info(dev, "Wait for M3 completion\n");
750
751	ret = wait_event_timeout(mhi_cntrl->state_event,
752				 mhi_cntrl->dev_state == MHI_STATE_M3 ||
753				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
754				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
755
756	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
757		dev_err(dev,
758			"Did not enter M3 state, MHI state: %s, PM state: %s\n",
759			TO_MHI_STATE_STR(mhi_cntrl->dev_state),
760			to_mhi_pm_state_str(mhi_cntrl->pm_state));
761		return -EIO;
762	}
763
764	/* Notify clients about entering LPM */
765	list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) {
766		mutex_lock(&itr->mutex);
767		if (itr->mhi_dev)
768			mhi_notify(itr->mhi_dev, MHI_CB_LPM_ENTER);
769		mutex_unlock(&itr->mutex);
770	}
771
772	return 0;
773}
774EXPORT_SYMBOL_GPL(mhi_pm_suspend);
775
776int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
777{
778	struct mhi_chan *itr, *tmp;
779	struct device *dev = &mhi_cntrl->mhi_dev->dev;
780	enum mhi_pm_state cur_state;
781	int ret;
782
783	dev_info(dev, "Entered with PM state: %s, MHI state: %s\n",
784		 to_mhi_pm_state_str(mhi_cntrl->pm_state),
785		 TO_MHI_STATE_STR(mhi_cntrl->dev_state));
786
787	if (mhi_cntrl->pm_state == MHI_PM_DISABLE)
788		return 0;
789
790	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))
791		return -EIO;
792
793	/* Notify clients about exiting LPM */
794	list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) {
795		mutex_lock(&itr->mutex);
796		if (itr->mhi_dev)
797			mhi_notify(itr->mhi_dev, MHI_CB_LPM_EXIT);
798		mutex_unlock(&itr->mutex);
799	}
800
801	write_lock_irq(&mhi_cntrl->pm_lock);
802	cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_EXIT);
803	if (cur_state != MHI_PM_M3_EXIT) {
804		write_unlock_irq(&mhi_cntrl->pm_lock);
805		dev_info(dev,
806			 "Error setting to PM state: %s from: %s\n",
807			 to_mhi_pm_state_str(MHI_PM_M3_EXIT),
808			 to_mhi_pm_state_str(mhi_cntrl->pm_state));
809		return -EIO;
810	}
811
812	/* Set MHI to M0 and wait for completion */
813	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M0);
814	write_unlock_irq(&mhi_cntrl->pm_lock);
815
816	ret = wait_event_timeout(mhi_cntrl->state_event,
817				 mhi_cntrl->dev_state == MHI_STATE_M0 ||
818				 mhi_cntrl->dev_state == MHI_STATE_M2 ||
819				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
820				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
821
822	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
823		dev_err(dev,
824			"Did not enter M0 state, MHI state: %s, PM state: %s\n",
825			TO_MHI_STATE_STR(mhi_cntrl->dev_state),
826			to_mhi_pm_state_str(mhi_cntrl->pm_state));
827		return -EIO;
828	}
829
830	return 0;
831}
832EXPORT_SYMBOL_GPL(mhi_pm_resume);
833
834int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl)
835{
836	int ret;
837
838	/* Wake up the device */
839	read_lock_bh(&mhi_cntrl->pm_lock);
840	mhi_cntrl->wake_get(mhi_cntrl, true);
841	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
842		mhi_trigger_resume(mhi_cntrl);
843	read_unlock_bh(&mhi_cntrl->pm_lock);
844
845	ret = wait_event_timeout(mhi_cntrl->state_event,
846				 mhi_cntrl->pm_state == MHI_PM_M0 ||
847				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
848				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
849
850	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
851		read_lock_bh(&mhi_cntrl->pm_lock);
852		mhi_cntrl->wake_put(mhi_cntrl, false);
853		read_unlock_bh(&mhi_cntrl->pm_lock);
854		return -EIO;
855	}
856
857	return 0;
858}
859
860/* Assert device wake db */
861static void mhi_assert_dev_wake(struct mhi_controller *mhi_cntrl, bool force)
862{
863	unsigned long flags;
864
865	/*
866	 * If force flag is set, then increment the wake count value and
867	 * ring wake db
868	 */
869	if (unlikely(force)) {
870		spin_lock_irqsave(&mhi_cntrl->wlock, flags);
871		atomic_inc(&mhi_cntrl->dev_wake);
872		if (MHI_WAKE_DB_FORCE_SET_VALID(mhi_cntrl->pm_state) &&
873		    !mhi_cntrl->wake_set) {
874			mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 1);
875			mhi_cntrl->wake_set = true;
876		}
877		spin_unlock_irqrestore(&mhi_cntrl->wlock, flags);
878	} else {
879		/*
880		 * If resources are already requested, then just increment
881		 * the wake count value and return
882		 */
883		if (likely(atomic_add_unless(&mhi_cntrl->dev_wake, 1, 0)))
884			return;
885
886		spin_lock_irqsave(&mhi_cntrl->wlock, flags);
887		if ((atomic_inc_return(&mhi_cntrl->dev_wake) == 1) &&
888		    MHI_WAKE_DB_SET_VALID(mhi_cntrl->pm_state) &&
889		    !mhi_cntrl->wake_set) {
890			mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 1);
891			mhi_cntrl->wake_set = true;
892		}
893		spin_unlock_irqrestore(&mhi_cntrl->wlock, flags);
894	}
895}
896
897/* De-assert device wake db */
898static void mhi_deassert_dev_wake(struct mhi_controller *mhi_cntrl,
899				  bool override)
900{
901	unsigned long flags;
902
903	/*
904	 * Only continue if there is a single resource, else just decrement
905	 * and return
906	 */
907	if (likely(atomic_add_unless(&mhi_cntrl->dev_wake, -1, 1)))
908		return;
909
910	spin_lock_irqsave(&mhi_cntrl->wlock, flags);
911	if ((atomic_dec_return(&mhi_cntrl->dev_wake) == 0) &&
912	    MHI_WAKE_DB_CLEAR_VALID(mhi_cntrl->pm_state) && !override &&
913	    mhi_cntrl->wake_set) {
914		mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 0);
915		mhi_cntrl->wake_set = false;
916	}
917	spin_unlock_irqrestore(&mhi_cntrl->wlock, flags);
918}
919
920int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
921{
922	enum mhi_state state;
923	enum mhi_ee_type current_ee;
924	enum dev_st_transition next_state;
925	struct device *dev = &mhi_cntrl->mhi_dev->dev;
926	u32 val;
927	int ret;
928
929	dev_info(dev, "Requested to power ON\n");
930
931	if (mhi_cntrl->nr_irqs < 1)
932		return -EINVAL;
933
934	/* Supply default wake routines if not provided by controller driver */
935	if (!mhi_cntrl->wake_get || !mhi_cntrl->wake_put ||
936	    !mhi_cntrl->wake_toggle) {
937		mhi_cntrl->wake_get = mhi_assert_dev_wake;
938		mhi_cntrl->wake_put = mhi_deassert_dev_wake;
939		mhi_cntrl->wake_toggle = (mhi_cntrl->db_access & MHI_PM_M2) ?
940			mhi_toggle_dev_wake_nop : mhi_toggle_dev_wake;
941	}
942
943	mutex_lock(&mhi_cntrl->pm_mutex);
944	mhi_cntrl->pm_state = MHI_PM_DISABLE;
945
946	if (!mhi_cntrl->pre_init) {
947		/* Setup device context */
948		ret = mhi_init_dev_ctxt(mhi_cntrl);
949		if (ret)
950			goto error_dev_ctxt;
951	}
952
953	ret = mhi_init_irq_setup(mhi_cntrl);
954	if (ret)
955		goto error_setup_irq;
956
957	/* Setup BHI offset & INTVEC */
958	write_lock_irq(&mhi_cntrl->pm_lock);
959	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIOFF, &val);
960	if (ret) {
961		write_unlock_irq(&mhi_cntrl->pm_lock);
962		goto error_bhi_offset;
963	}
964
965	mhi_cntrl->bhi = mhi_cntrl->regs + val;
966
967	/* Setup BHIE offset */
968	if (mhi_cntrl->fbc_download) {
969		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF, &val);
970		if (ret) {
971			write_unlock_irq(&mhi_cntrl->pm_lock);
972			dev_err(dev, "Error reading BHIE offset\n");
973			goto error_bhi_offset;
974		}
975
976		mhi_cntrl->bhie = mhi_cntrl->regs + val;
977	}
978
979	mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
980	mhi_cntrl->pm_state = MHI_PM_POR;
981	mhi_cntrl->ee = MHI_EE_MAX;
982	current_ee = mhi_get_exec_env(mhi_cntrl);
983	write_unlock_irq(&mhi_cntrl->pm_lock);
984
985	/* Confirm that the device is in valid exec env */
986	if (!MHI_IN_PBL(current_ee) && current_ee != MHI_EE_AMSS) {
987		dev_err(dev, "Not a valid EE for power on\n");
988		ret = -EIO;
989		goto error_bhi_offset;
990	}
991
992	state = mhi_get_mhi_state(mhi_cntrl);
993	if (state == MHI_STATE_SYS_ERR) {
994		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
995		ret = wait_event_timeout(mhi_cntrl->state_event,
996				MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) ||
997					mhi_read_reg_field(mhi_cntrl,
998							   mhi_cntrl->regs,
999							   MHICTRL,
1000							   MHICTRL_RESET_MASK,
1001							   MHICTRL_RESET_SHIFT,
1002							   &val) ||
1003					!val,
1004				msecs_to_jiffies(mhi_cntrl->timeout_ms));
1005		if (!ret) {
1006			ret = -EIO;
1007			dev_info(dev, "Failed to reset MHI due to syserr state\n");
1008			goto error_bhi_offset;
1009		}
1010
1011		/*
1012		 * device cleares INTVEC as part of RESET processing,
1013		 * re-program it
1014		 */
1015		mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
1016	}
1017
1018	/* Transition to next state */
1019	next_state = MHI_IN_PBL(current_ee) ?
1020		DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY;
1021
1022	mhi_queue_state_transition(mhi_cntrl, next_state);
1023
1024	mutex_unlock(&mhi_cntrl->pm_mutex);
1025
1026	dev_info(dev, "Power on setup success\n");
1027
1028	return 0;
1029
1030error_bhi_offset:
1031	mhi_deinit_free_irq(mhi_cntrl);
1032
1033error_setup_irq:
1034	if (!mhi_cntrl->pre_init)
1035		mhi_deinit_dev_ctxt(mhi_cntrl);
1036
1037error_dev_ctxt:
1038	mutex_unlock(&mhi_cntrl->pm_mutex);
1039
1040	return ret;
1041}
1042EXPORT_SYMBOL_GPL(mhi_async_power_up);
1043
1044void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
1045{
1046	enum mhi_pm_state cur_state;
1047	struct device *dev = &mhi_cntrl->mhi_dev->dev;
1048
1049	/* If it's not a graceful shutdown, force MHI to linkdown state */
1050	if (!graceful) {
1051		mutex_lock(&mhi_cntrl->pm_mutex);
1052		write_lock_irq(&mhi_cntrl->pm_lock);
1053		cur_state = mhi_tryset_pm_state(mhi_cntrl,
1054						MHI_PM_LD_ERR_FATAL_DETECT);
1055		write_unlock_irq(&mhi_cntrl->pm_lock);
1056		mutex_unlock(&mhi_cntrl->pm_mutex);
1057		if (cur_state != MHI_PM_LD_ERR_FATAL_DETECT)
1058			dev_dbg(dev, "Failed to move to state: %s from: %s\n",
1059				to_mhi_pm_state_str(MHI_PM_LD_ERR_FATAL_DETECT),
1060				to_mhi_pm_state_str(mhi_cntrl->pm_state));
1061	}
1062
1063	mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE);
1064
1065	/* Wait for shutdown to complete */
1066	flush_work(&mhi_cntrl->st_worker);
1067
1068	mhi_deinit_free_irq(mhi_cntrl);
1069
1070	if (!mhi_cntrl->pre_init) {
1071		/* Free all allocated resources */
1072		if (mhi_cntrl->fbc_image) {
1073			mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
1074			mhi_cntrl->fbc_image = NULL;
1075		}
1076		mhi_deinit_dev_ctxt(mhi_cntrl);
1077	}
1078}
1079EXPORT_SYMBOL_GPL(mhi_power_down);
1080
1081int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
1082{
1083	int ret = mhi_async_power_up(mhi_cntrl);
1084
1085	if (ret)
1086		return ret;
1087
1088	wait_event_timeout(mhi_cntrl->state_event,
1089			   MHI_IN_MISSION_MODE(mhi_cntrl->ee) ||
1090			   MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
1091			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
1092
1093	ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;
1094	if (ret)
1095		mhi_power_down(mhi_cntrl, false);
1096
1097	return ret;
1098}
1099EXPORT_SYMBOL(mhi_sync_power_up);
1100
1101int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl)
1102{
1103	struct device *dev = &mhi_cntrl->mhi_dev->dev;
1104	int ret;
1105
1106	/* Check if device is already in RDDM */
1107	if (mhi_cntrl->ee == MHI_EE_RDDM)
1108		return 0;
1109
1110	dev_dbg(dev, "Triggering SYS_ERR to force RDDM state\n");
1111	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR);
1112
1113	/* Wait for RDDM event */
1114	ret = wait_event_timeout(mhi_cntrl->state_event,
1115				 mhi_cntrl->ee == MHI_EE_RDDM,
1116				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
1117	ret = ret ? 0 : -EIO;
1118
1119	return ret;
1120}
1121EXPORT_SYMBOL_GPL(mhi_force_rddm_mode);
1122
1123void mhi_device_get(struct mhi_device *mhi_dev)
1124{
1125	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1126
1127	mhi_dev->dev_wake++;
1128	read_lock_bh(&mhi_cntrl->pm_lock);
1129	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
1130		mhi_trigger_resume(mhi_cntrl);
1131
1132	mhi_cntrl->wake_get(mhi_cntrl, true);
1133	read_unlock_bh(&mhi_cntrl->pm_lock);
1134}
1135EXPORT_SYMBOL_GPL(mhi_device_get);
1136
1137int mhi_device_get_sync(struct mhi_device *mhi_dev)
1138{
1139	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1140	int ret;
1141
1142	ret = __mhi_device_get_sync(mhi_cntrl);
1143	if (!ret)
1144		mhi_dev->dev_wake++;
1145
1146	return ret;
1147}
1148EXPORT_SYMBOL_GPL(mhi_device_get_sync);
1149
1150void mhi_device_put(struct mhi_device *mhi_dev)
1151{
1152	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1153
1154	mhi_dev->dev_wake--;
1155	read_lock_bh(&mhi_cntrl->pm_lock);
1156	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state))
1157		mhi_trigger_resume(mhi_cntrl);
1158
1159	mhi_cntrl->wake_put(mhi_cntrl, false);
1160	read_unlock_bh(&mhi_cntrl->pm_lock);
1161}
1162EXPORT_SYMBOL_GPL(mhi_device_put);
1163