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