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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  */
44 static 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 
mhi_tryset_pm_state(struct mhi_controller * mhi_cntrl,enum mhi_pm_state state)110 enum 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 
mhi_set_mhi_state(struct mhi_controller * mhi_cntrl,enum mhi_state state)129 void 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 */
mhi_toggle_dev_wake_nop(struct mhi_controller * mhi_cntrl)142 static void mhi_toggle_dev_wake_nop(struct mhi_controller *mhi_cntrl)
143 {
144 }
145 
mhi_toggle_dev_wake(struct mhi_controller * mhi_cntrl)146 static 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 */
mhi_ready_state_transition(struct mhi_controller * mhi_cntrl)153 int 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 
238 error_mmio:
239 	read_unlock_bh(&mhi_cntrl->pm_lock);
240 
241 	return -EIO;
242 }
243 
mhi_pm_m0_transition(struct mhi_controller * mhi_cntrl)244 int 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  */
mhi_pm_m1_transition(struct mhi_controller * mhi_cntrl)319 void 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 */
mhi_pm_m3_transition(struct mhi_controller * mhi_cntrl)355 int 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 */
mhi_pm_mission_mode_transition(struct mhi_controller * mhi_cntrl)376 static 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 
440 error_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 */
mhi_pm_disable_transition(struct mhi_controller * mhi_cntrl,enum mhi_pm_state transition_state)448 static 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 
522 skip_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 */
mhi_queue_state_transition(struct mhi_controller * mhi_cntrl,enum dev_st_transition state)595 int 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 */
mhi_pm_sys_err_handler(struct mhi_controller * mhi_cntrl)615 void 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 */
mhi_pm_st_worker(struct work_struct * work)629 void 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 
mhi_pm_suspend(struct mhi_controller * mhi_cntrl)688 int 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 }
774 EXPORT_SYMBOL_GPL(mhi_pm_suspend);
775 
mhi_pm_resume(struct mhi_controller * mhi_cntrl)776 int 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 }
832 EXPORT_SYMBOL_GPL(mhi_pm_resume);
833 
__mhi_device_get_sync(struct mhi_controller * mhi_cntrl)834 int __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 */
mhi_assert_dev_wake(struct mhi_controller * mhi_cntrl,bool force)861 static 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 */
mhi_deassert_dev_wake(struct mhi_controller * mhi_cntrl,bool override)898 static 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 
mhi_async_power_up(struct mhi_controller * mhi_cntrl)920 int 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 
1030 error_bhi_offset:
1031 	mhi_deinit_free_irq(mhi_cntrl);
1032 
1033 error_setup_irq:
1034 	if (!mhi_cntrl->pre_init)
1035 		mhi_deinit_dev_ctxt(mhi_cntrl);
1036 
1037 error_dev_ctxt:
1038 	mutex_unlock(&mhi_cntrl->pm_mutex);
1039 
1040 	return ret;
1041 }
1042 EXPORT_SYMBOL_GPL(mhi_async_power_up);
1043 
mhi_power_down(struct mhi_controller * mhi_cntrl,bool graceful)1044 void 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 }
1079 EXPORT_SYMBOL_GPL(mhi_power_down);
1080 
mhi_sync_power_up(struct mhi_controller * mhi_cntrl)1081 int 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 }
1099 EXPORT_SYMBOL(mhi_sync_power_up);
1100 
mhi_force_rddm_mode(struct mhi_controller * mhi_cntrl)1101 int 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 }
1121 EXPORT_SYMBOL_GPL(mhi_force_rddm_mode);
1122 
mhi_device_get(struct mhi_device * mhi_dev)1123 void 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 }
1135 EXPORT_SYMBOL_GPL(mhi_device_get);
1136 
mhi_device_get_sync(struct mhi_device * mhi_dev)1137 int 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 }
1148 EXPORT_SYMBOL_GPL(mhi_device_get_sync);
1149 
mhi_device_put(struct mhi_device * mhi_dev)1150 void 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 }
1162 EXPORT_SYMBOL_GPL(mhi_device_put);
1163