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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015, Sony Mobile Communications AB.
4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5 */
6
7#include <linux/interrupt.h>
8#include <linux/list.h>
9#include <linux/io.h>
10#include <linux/of.h>
11#include <linux/irq.h>
12#include <linux/irqdomain.h>
13#include <linux/mailbox_client.h>
14#include <linux/mfd/syscon.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/regmap.h>
18#include <linux/soc/qcom/smem.h>
19#include <linux/soc/qcom/smem_state.h>
20#include <linux/spinlock.h>
21
22/*
23 * The Shared Memory Point to Point (SMP2P) protocol facilitates communication
24 * of a single 32-bit value between two processors. Each value has a single
25 * writer (the local side) and a single reader (the remote side). Values are
26 * uniquely identified in the system by the directed edge (local processor ID
27 * to remote processor ID) and a string identifier.
28 *
29 * Each processor is responsible for creating the outgoing SMEM items and each
30 * item is writable by the local processor and readable by the remote
31 * processor. By using two separate SMEM items that are single-reader and
32 * single-writer, SMP2P does not require any remote locking mechanisms.
33 *
34 * The driver uses the Linux GPIO and interrupt framework to expose a virtual
35 * GPIO for each outbound entry and a virtual interrupt controller for each
36 * inbound entry.
37 */
38
39#define SMP2P_MAX_ENTRY 16
40#define SMP2P_MAX_ENTRY_NAME 16
41
42#define SMP2P_FEATURE_SSR_ACK 0x1
43
44#define SMP2P_MAGIC 0x504d5324
45
46/**
47 * struct smp2p_smem_item - in memory communication structure
48 * @magic: magic number
49 * @version: version - must be 1
50 * @features: features flag - currently unused
51 * @local_pid: processor id of sending end
52 * @remote_pid: processor id of receiving end
53 * @total_entries: number of entries - always SMP2P_MAX_ENTRY
54 * @valid_entries: number of allocated entries
55 * @flags:
56 * @entries: individual communication entries
57 * @name: name of the entry
58 * @value: content of the entry
59 */
60struct smp2p_smem_item {
61 u32 magic;
62 u8 version;
63 unsigned features:24;
64 u16 local_pid;
65 u16 remote_pid;
66 u16 total_entries;
67 u16 valid_entries;
68 u32 flags;
69
70 struct {
71 u8 name[SMP2P_MAX_ENTRY_NAME];
72 u32 value;
73 } entries[SMP2P_MAX_ENTRY];
74} __packed;
75
76/**
77 * struct smp2p_entry - driver context matching one entry
78 * @node: list entry to keep track of allocated entries
79 * @smp2p: reference to the device driver context
80 * @name: name of the entry, to match against smp2p_smem_item
81 * @value: pointer to smp2p_smem_item entry value
82 * @last_value: last handled value
83 * @domain: irq_domain for inbound entries
84 * @irq_enabled:bitmap to track enabled irq bits
85 * @irq_rising: bitmap to mark irq bits for rising detection
86 * @irq_falling:bitmap to mark irq bits for falling detection
87 * @state: smem state handle
88 * @lock: spinlock to protect read-modify-write of the value
89 */
90struct smp2p_entry {
91 struct list_head node;
92 struct qcom_smp2p *smp2p;
93
94 const char *name;
95 u32 *value;
96 u32 last_value;
97
98 struct irq_domain *domain;
99 DECLARE_BITMAP(irq_enabled, 32);
100 DECLARE_BITMAP(irq_rising, 32);
101 DECLARE_BITMAP(irq_falling, 32);
102
103 struct qcom_smem_state *state;
104
105 spinlock_t lock;
106};
107
108#define SMP2P_INBOUND 0
109#define SMP2P_OUTBOUND 1
110
111/**
112 * struct qcom_smp2p - device driver context
113 * @dev: device driver handle
114 * @in: pointer to the inbound smem item
115 * @smem_items: ids of the two smem items
116 * @valid_entries: already scanned inbound entries
117 * @local_pid: processor id of the inbound edge
118 * @remote_pid: processor id of the outbound edge
119 * @ipc_regmap: regmap for the outbound ipc
120 * @ipc_offset: offset within the regmap
121 * @ipc_bit: bit in regmap@offset to kick to signal remote processor
122 * @mbox_client: mailbox client handle
123 * @mbox_chan: apcs ipc mailbox channel handle
124 * @inbound: list of inbound entries
125 * @outbound: list of outbound entries
126 */
127struct qcom_smp2p {
128 struct device *dev;
129
130 struct smp2p_smem_item *in;
131 struct smp2p_smem_item *out;
132
133 unsigned smem_items[SMP2P_OUTBOUND + 1];
134
135 unsigned valid_entries;
136
137 unsigned local_pid;
138 unsigned remote_pid;
139
140 struct regmap *ipc_regmap;
141 int ipc_offset;
142 int ipc_bit;
143
144 struct mbox_client mbox_client;
145 struct mbox_chan *mbox_chan;
146
147 struct list_head inbound;
148 struct list_head outbound;
149};
150
151static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
152{
153 /* Make sure any updated data is written before the kick */
154 wmb();
155
156 if (smp2p->mbox_chan) {
157 mbox_send_message(smp2p->mbox_chan, NULL);
158 mbox_client_txdone(smp2p->mbox_chan, 0);
159 } else {
160 regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
161 }
162}
163
164/**
165 * qcom_smp2p_intr() - interrupt handler for incoming notifications
166 * @irq: unused
167 * @data: smp2p driver context
168 *
169 * Handle notifications from the remote side to handle newly allocated entries
170 * or any changes to the state bits of existing entries.
171 */
172static irqreturn_t qcom_smp2p_intr(int irq, void *data)
173{
174 struct smp2p_smem_item *in;
175 struct smp2p_entry *entry;
176 struct qcom_smp2p *smp2p = data;
177 unsigned smem_id = smp2p->smem_items[SMP2P_INBOUND];
178 unsigned pid = smp2p->remote_pid;
179 size_t size;
180 int irq_pin;
181 u32 status;
182 char buf[SMP2P_MAX_ENTRY_NAME];
183 u32 val;
184 int i;
185
186 in = smp2p->in;
187
188 /* Acquire smem item, if not already found */
189 if (!in) {
190 in = qcom_smem_get(pid, smem_id, &size);
191 if (IS_ERR(in)) {
192 dev_err(smp2p->dev,
193 "Unable to acquire remote smp2p item\n");
194 return IRQ_HANDLED;
195 }
196
197 smp2p->in = in;
198 }
199
200 /* Match newly created entries */
201 for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
202 list_for_each_entry(entry, &smp2p->inbound, node) {
203 memcpy(buf, in->entries[i].name, sizeof(buf));
204 if (!strcmp(buf, entry->name)) {
205 entry->value = &in->entries[i].value;
206 break;
207 }
208 }
209 }
210 smp2p->valid_entries = i;
211
212 /* Fire interrupts based on any value changes */
213 list_for_each_entry(entry, &smp2p->inbound, node) {
214 /* Ignore entries not yet allocated by the remote side */
215 if (!entry->value)
216 continue;
217
218 val = readl(entry->value);
219
220 status = val ^ entry->last_value;
221 entry->last_value = val;
222
223 /* No changes of this entry? */
224 if (!status)
225 continue;
226
227 for_each_set_bit(i, entry->irq_enabled, 32) {
228 if (!(status & BIT(i)))
229 continue;
230
231 if ((val & BIT(i) && test_bit(i, entry->irq_rising)) ||
232 (!(val & BIT(i)) && test_bit(i, entry->irq_falling))) {
233 irq_pin = irq_find_mapping(entry->domain, i);
234 handle_nested_irq(irq_pin);
235 }
236 }
237 }
238
239 return IRQ_HANDLED;
240}
241
242static void smp2p_mask_irq(struct irq_data *irqd)
243{
244 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
245 irq_hw_number_t irq = irqd_to_hwirq(irqd);
246
247 clear_bit(irq, entry->irq_enabled);
248}
249
250static void smp2p_unmask_irq(struct irq_data *irqd)
251{
252 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
253 irq_hw_number_t irq = irqd_to_hwirq(irqd);
254
255 set_bit(irq, entry->irq_enabled);
256}
257
258static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)
259{
260 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
261 irq_hw_number_t irq = irqd_to_hwirq(irqd);
262
263 if (!(type & IRQ_TYPE_EDGE_BOTH))
264 return -EINVAL;
265
266 if (type & IRQ_TYPE_EDGE_RISING)
267 set_bit(irq, entry->irq_rising);
268 else
269 clear_bit(irq, entry->irq_rising);
270
271 if (type & IRQ_TYPE_EDGE_FALLING)
272 set_bit(irq, entry->irq_falling);
273 else
274 clear_bit(irq, entry->irq_falling);
275
276 return 0;
277}
278
279static struct irq_chip smp2p_irq_chip = {
280 .name = "smp2p",
281 .irq_mask = smp2p_mask_irq,
282 .irq_unmask = smp2p_unmask_irq,
283 .irq_set_type = smp2p_set_irq_type,
284};
285
286static int smp2p_irq_map(struct irq_domain *d,
287 unsigned int irq,
288 irq_hw_number_t hw)
289{
290 struct smp2p_entry *entry = d->host_data;
291
292 irq_set_chip_and_handler(irq, &smp2p_irq_chip, handle_level_irq);
293 irq_set_chip_data(irq, entry);
294 irq_set_nested_thread(irq, 1);
295 irq_set_noprobe(irq);
296
297 return 0;
298}
299
300static const struct irq_domain_ops smp2p_irq_ops = {
301 .map = smp2p_irq_map,
302 .xlate = irq_domain_xlate_twocell,
303};
304
305static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
306 struct smp2p_entry *entry,
307 struct device_node *node)
308{
309 entry->domain = irq_domain_add_linear(node, 32, &smp2p_irq_ops, entry);
310 if (!entry->domain) {
311 dev_err(smp2p->dev, "failed to add irq_domain\n");
312 return -ENOMEM;
313 }
314
315 return 0;
316}
317
318static int smp2p_update_bits(void *data, u32 mask, u32 value)
319{
320 struct smp2p_entry *entry = data;
321 u32 orig;
322 u32 val;
323
324 spin_lock(&entry->lock);
325 val = orig = readl(entry->value);
326 val &= ~mask;
327 val |= value;
328 writel(val, entry->value);
329 spin_unlock(&entry->lock);
330
331 if (val != orig)
332 qcom_smp2p_kick(entry->smp2p);
333
334 return 0;
335}
336
337static const struct qcom_smem_state_ops smp2p_state_ops = {
338 .update_bits = smp2p_update_bits,
339};
340
341static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
342 struct smp2p_entry *entry,
343 struct device_node *node)
344{
345 struct smp2p_smem_item *out = smp2p->out;
346 char buf[SMP2P_MAX_ENTRY_NAME] = {};
347
348 /* Allocate an entry from the smem item */
349 strlcpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
350 memcpy(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
351
352 /* Make the logical entry reference the physical value */
353 entry->value = &out->entries[out->valid_entries].value;
354
355 out->valid_entries++;
356
357 entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);
358 if (IS_ERR(entry->state)) {
359 dev_err(smp2p->dev, "failed to register qcom_smem_state\n");
360 return PTR_ERR(entry->state);
361 }
362
363 return 0;
364}
365
366static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
367{
368 struct smp2p_smem_item *out;
369 unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
370 unsigned pid = smp2p->remote_pid;
371 int ret;
372
373 ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));
374 if (ret < 0 && ret != -EEXIST) {
375 if (ret != -EPROBE_DEFER)
376 dev_err(smp2p->dev,
377 "unable to allocate local smp2p item\n");
378 return ret;
379 }
380
381 out = qcom_smem_get(pid, smem_id, NULL);
382 if (IS_ERR(out)) {
383 dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");
384 return PTR_ERR(out);
385 }
386
387 memset(out, 0, sizeof(*out));
388 out->magic = SMP2P_MAGIC;
389 out->local_pid = smp2p->local_pid;
390 out->remote_pid = smp2p->remote_pid;
391 out->total_entries = SMP2P_MAX_ENTRY;
392 out->valid_entries = 0;
393
394 /*
395 * Make sure the rest of the header is written before we validate the
396 * item by writing a valid version number.
397 */
398 wmb();
399 out->version = 1;
400
401 qcom_smp2p_kick(smp2p);
402
403 smp2p->out = out;
404
405 return 0;
406}
407
408static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)
409{
410 struct device_node *syscon;
411 struct device *dev = smp2p->dev;
412 const char *key;
413 int ret;
414
415 syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0);
416 if (!syscon) {
417 dev_err(dev, "no qcom,ipc node\n");
418 return -ENODEV;
419 }
420
421 smp2p->ipc_regmap = syscon_node_to_regmap(syscon);
422 if (IS_ERR(smp2p->ipc_regmap))
423 return PTR_ERR(smp2p->ipc_regmap);
424
425 key = "qcom,ipc";
426 ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset);
427 if (ret < 0) {
428 dev_err(dev, "no offset in %s\n", key);
429 return -EINVAL;
430 }
431
432 ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit);
433 if (ret < 0) {
434 dev_err(dev, "no bit in %s\n", key);
435 return -EINVAL;
436 }
437
438 return 0;
439}
440
441static int qcom_smp2p_probe(struct platform_device *pdev)
442{
443 struct smp2p_entry *entry;
444 struct device_node *node;
445 struct qcom_smp2p *smp2p;
446 const char *key;
447 int irq;
448 int ret;
449
450 smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL);
451 if (!smp2p)
452 return -ENOMEM;
453
454 smp2p->dev = &pdev->dev;
455 INIT_LIST_HEAD(&smp2p->inbound);
456 INIT_LIST_HEAD(&smp2p->outbound);
457
458 platform_set_drvdata(pdev, smp2p);
459
460 key = "qcom,smem";
461 ret = of_property_read_u32_array(pdev->dev.of_node, key,
462 smp2p->smem_items, 2);
463 if (ret)
464 return ret;
465
466 key = "qcom,local-pid";
467 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);
468 if (ret)
469 goto report_read_failure;
470
471 key = "qcom,remote-pid";
472 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
473 if (ret)
474 goto report_read_failure;
475
476 irq = platform_get_irq(pdev, 0);
477 if (irq < 0)
478 return irq;
479
480 smp2p->mbox_client.dev = &pdev->dev;
481 smp2p->mbox_client.knows_txdone = true;
482 smp2p->mbox_chan = mbox_request_channel(&smp2p->mbox_client, 0);
483 if (IS_ERR(smp2p->mbox_chan)) {
484 if (PTR_ERR(smp2p->mbox_chan) != -ENODEV)
485 return PTR_ERR(smp2p->mbox_chan);
486
487 smp2p->mbox_chan = NULL;
488
489 ret = smp2p_parse_ipc(smp2p);
490 if (ret)
491 return ret;
492 }
493
494 ret = qcom_smp2p_alloc_outbound_item(smp2p);
495 if (ret < 0)
496 goto release_mbox;
497
498 for_each_available_child_of_node(pdev->dev.of_node, node) {
499 entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);
500 if (!entry) {
501 ret = -ENOMEM;
502 goto unwind_interfaces;
503 }
504
505 entry->smp2p = smp2p;
506 spin_lock_init(&entry->lock);
507
508 ret = of_property_read_string(node, "qcom,entry-name", &entry->name);
509 if (ret < 0)
510 goto unwind_interfaces;
511
512 if (of_property_read_bool(node, "interrupt-controller")) {
513 ret = qcom_smp2p_inbound_entry(smp2p, entry, node);
514 if (ret < 0)
515 goto unwind_interfaces;
516
517 list_add(&entry->node, &smp2p->inbound);
518 } else {
519 ret = qcom_smp2p_outbound_entry(smp2p, entry, node);
520 if (ret < 0)
521 goto unwind_interfaces;
522
523 list_add(&entry->node, &smp2p->outbound);
524 }
525 }
526
527 /* Kick the outgoing edge after allocating entries */
528 qcom_smp2p_kick(smp2p);
529
530 ret = devm_request_threaded_irq(&pdev->dev, irq,
531 NULL, qcom_smp2p_intr,
532 IRQF_ONESHOT,
533 "smp2p", (void *)smp2p);
534 if (ret) {
535 dev_err(&pdev->dev, "failed to request interrupt\n");
536 goto unwind_interfaces;
537 }
538
539
540 return 0;
541
542unwind_interfaces:
543 list_for_each_entry(entry, &smp2p->inbound, node)
544 irq_domain_remove(entry->domain);
545
546 list_for_each_entry(entry, &smp2p->outbound, node)
547 qcom_smem_state_unregister(entry->state);
548
549 smp2p->out->valid_entries = 0;
550
551release_mbox:
552 mbox_free_channel(smp2p->mbox_chan);
553
554 return ret;
555
556report_read_failure:
557 dev_err(&pdev->dev, "failed to read %s\n", key);
558 return -EINVAL;
559}
560
561static int qcom_smp2p_remove(struct platform_device *pdev)
562{
563 struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);
564 struct smp2p_entry *entry;
565
566 list_for_each_entry(entry, &smp2p->inbound, node)
567 irq_domain_remove(entry->domain);
568
569 list_for_each_entry(entry, &smp2p->outbound, node)
570 qcom_smem_state_unregister(entry->state);
571
572 mbox_free_channel(smp2p->mbox_chan);
573
574 smp2p->out->valid_entries = 0;
575
576 return 0;
577}
578
579static const struct of_device_id qcom_smp2p_of_match[] = {
580 { .compatible = "qcom,smp2p" },
581 {}
582};
583MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match);
584
585static struct platform_driver qcom_smp2p_driver = {
586 .probe = qcom_smp2p_probe,
587 .remove = qcom_smp2p_remove,
588 .driver = {
589 .name = "qcom_smp2p",
590 .of_match_table = qcom_smp2p_of_match,
591 },
592};
593module_platform_driver(qcom_smp2p_driver);
594
595MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver");
596MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015, Sony Mobile Communications AB.
4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5 */
6
7#include <linux/interrupt.h>
8#include <linux/list.h>
9#include <linux/io.h>
10#include <linux/of.h>
11#include <linux/irq.h>
12#include <linux/irqdomain.h>
13#include <linux/mailbox_client.h>
14#include <linux/mfd/syscon.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/pm_wakeirq.h>
18#include <linux/regmap.h>
19#include <linux/seq_file.h>
20#include <linux/soc/qcom/smem.h>
21#include <linux/soc/qcom/smem_state.h>
22#include <linux/spinlock.h>
23
24/*
25 * The Shared Memory Point to Point (SMP2P) protocol facilitates communication
26 * of a single 32-bit value between two processors. Each value has a single
27 * writer (the local side) and a single reader (the remote side). Values are
28 * uniquely identified in the system by the directed edge (local processor ID
29 * to remote processor ID) and a string identifier.
30 *
31 * Each processor is responsible for creating the outgoing SMEM items and each
32 * item is writable by the local processor and readable by the remote
33 * processor. By using two separate SMEM items that are single-reader and
34 * single-writer, SMP2P does not require any remote locking mechanisms.
35 *
36 * The driver uses the Linux GPIO and interrupt framework to expose a virtual
37 * GPIO for each outbound entry and a virtual interrupt controller for each
38 * inbound entry.
39 */
40
41#define SMP2P_MAX_ENTRY 16
42#define SMP2P_MAX_ENTRY_NAME 16
43
44#define SMP2P_FEATURE_SSR_ACK 0x1
45#define SMP2P_FLAGS_RESTART_DONE_BIT 0
46#define SMP2P_FLAGS_RESTART_ACK_BIT 1
47
48#define SMP2P_MAGIC 0x504d5324
49#define SMP2P_ALL_FEATURES SMP2P_FEATURE_SSR_ACK
50
51/**
52 * struct smp2p_smem_item - in memory communication structure
53 * @magic: magic number
54 * @version: version - must be 1
55 * @features: features flag - currently unused
56 * @local_pid: processor id of sending end
57 * @remote_pid: processor id of receiving end
58 * @total_entries: number of entries - always SMP2P_MAX_ENTRY
59 * @valid_entries: number of allocated entries
60 * @flags:
61 * @entries: individual communication entries
62 * @entries.name: name of the entry
63 * @entries.value: content of the entry
64 */
65struct smp2p_smem_item {
66 u32 magic;
67 u8 version;
68 unsigned features:24;
69 u16 local_pid;
70 u16 remote_pid;
71 u16 total_entries;
72 u16 valid_entries;
73 u32 flags;
74
75 struct {
76 u8 name[SMP2P_MAX_ENTRY_NAME];
77 u32 value;
78 } entries[SMP2P_MAX_ENTRY];
79} __packed;
80
81/**
82 * struct smp2p_entry - driver context matching one entry
83 * @node: list entry to keep track of allocated entries
84 * @smp2p: reference to the device driver context
85 * @name: name of the entry, to match against smp2p_smem_item
86 * @value: pointer to smp2p_smem_item entry value
87 * @last_value: last handled value
88 * @domain: irq_domain for inbound entries
89 * @irq_enabled:bitmap to track enabled irq bits
90 * @irq_rising: bitmap to mark irq bits for rising detection
91 * @irq_falling:bitmap to mark irq bits for falling detection
92 * @state: smem state handle
93 * @lock: spinlock to protect read-modify-write of the value
94 */
95struct smp2p_entry {
96 struct list_head node;
97 struct qcom_smp2p *smp2p;
98
99 const char *name;
100 u32 *value;
101 u32 last_value;
102
103 struct irq_domain *domain;
104 DECLARE_BITMAP(irq_enabled, 32);
105 DECLARE_BITMAP(irq_rising, 32);
106 DECLARE_BITMAP(irq_falling, 32);
107
108 struct qcom_smem_state *state;
109
110 spinlock_t lock;
111};
112
113#define SMP2P_INBOUND 0
114#define SMP2P_OUTBOUND 1
115
116/**
117 * struct qcom_smp2p - device driver context
118 * @dev: device driver handle
119 * @in: pointer to the inbound smem item
120 * @out: pointer to the outbound smem item
121 * @smem_items: ids of the two smem items
122 * @valid_entries: already scanned inbound entries
123 * @ssr_ack_enabled: SMP2P_FEATURE_SSR_ACK feature is supported and was enabled
124 * @ssr_ack: current cached state of the local ack bit
125 * @negotiation_done: whether negotiating finished
126 * @local_pid: processor id of the inbound edge
127 * @remote_pid: processor id of the outbound edge
128 * @ipc_regmap: regmap for the outbound ipc
129 * @ipc_offset: offset within the regmap
130 * @ipc_bit: bit in regmap@offset to kick to signal remote processor
131 * @mbox_client: mailbox client handle
132 * @mbox_chan: apcs ipc mailbox channel handle
133 * @inbound: list of inbound entries
134 * @outbound: list of outbound entries
135 */
136struct qcom_smp2p {
137 struct device *dev;
138
139 struct smp2p_smem_item *in;
140 struct smp2p_smem_item *out;
141
142 unsigned smem_items[SMP2P_OUTBOUND + 1];
143
144 unsigned valid_entries;
145
146 bool ssr_ack_enabled;
147 bool ssr_ack;
148 bool negotiation_done;
149
150 unsigned local_pid;
151 unsigned remote_pid;
152
153 struct regmap *ipc_regmap;
154 int ipc_offset;
155 int ipc_bit;
156
157 struct mbox_client mbox_client;
158 struct mbox_chan *mbox_chan;
159
160 struct list_head inbound;
161 struct list_head outbound;
162};
163
164#define CREATE_TRACE_POINTS
165#include "trace-smp2p.h"
166
167static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
168{
169 /* Make sure any updated data is written before the kick */
170 wmb();
171
172 if (smp2p->mbox_chan) {
173 mbox_send_message(smp2p->mbox_chan, NULL);
174 mbox_client_txdone(smp2p->mbox_chan, 0);
175 } else {
176 regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
177 }
178}
179
180static bool qcom_smp2p_check_ssr(struct qcom_smp2p *smp2p)
181{
182 struct smp2p_smem_item *in = smp2p->in;
183 bool restart;
184
185 if (!smp2p->ssr_ack_enabled)
186 return false;
187
188 restart = in->flags & BIT(SMP2P_FLAGS_RESTART_DONE_BIT);
189
190 return restart != smp2p->ssr_ack;
191}
192
193static void qcom_smp2p_do_ssr_ack(struct qcom_smp2p *smp2p)
194{
195 struct smp2p_smem_item *out = smp2p->out;
196 u32 val;
197
198 trace_smp2p_ssr_ack(smp2p->dev);
199 smp2p->ssr_ack = !smp2p->ssr_ack;
200
201 val = out->flags & ~BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
202 if (smp2p->ssr_ack)
203 val |= BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
204 out->flags = val;
205
206 qcom_smp2p_kick(smp2p);
207}
208
209static void qcom_smp2p_negotiate(struct qcom_smp2p *smp2p)
210{
211 struct smp2p_smem_item *out = smp2p->out;
212 struct smp2p_smem_item *in = smp2p->in;
213
214 if (in->version == out->version) {
215 out->features &= in->features;
216
217 if (out->features & SMP2P_FEATURE_SSR_ACK)
218 smp2p->ssr_ack_enabled = true;
219
220 smp2p->negotiation_done = true;
221 trace_smp2p_negotiate(smp2p->dev, out->features);
222 }
223}
224
225static void qcom_smp2p_notify_in(struct qcom_smp2p *smp2p)
226{
227 struct smp2p_smem_item *in;
228 struct smp2p_entry *entry;
229 int irq_pin;
230 u32 status;
231 char buf[SMP2P_MAX_ENTRY_NAME];
232 u32 val;
233 int i;
234
235 in = smp2p->in;
236
237 /* Match newly created entries */
238 for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
239 list_for_each_entry(entry, &smp2p->inbound, node) {
240 memcpy(buf, in->entries[i].name, sizeof(buf));
241 if (!strcmp(buf, entry->name)) {
242 entry->value = &in->entries[i].value;
243 break;
244 }
245 }
246 }
247 smp2p->valid_entries = i;
248
249 /* Fire interrupts based on any value changes */
250 list_for_each_entry(entry, &smp2p->inbound, node) {
251 /* Ignore entries not yet allocated by the remote side */
252 if (!entry->value)
253 continue;
254
255 val = readl(entry->value);
256
257 status = val ^ entry->last_value;
258 entry->last_value = val;
259
260 trace_smp2p_notify_in(entry, status, val);
261
262 /* No changes of this entry? */
263 if (!status)
264 continue;
265
266 for_each_set_bit(i, entry->irq_enabled, 32) {
267 if (!(status & BIT(i)))
268 continue;
269
270 if ((val & BIT(i) && test_bit(i, entry->irq_rising)) ||
271 (!(val & BIT(i)) && test_bit(i, entry->irq_falling))) {
272 irq_pin = irq_find_mapping(entry->domain, i);
273 handle_nested_irq(irq_pin);
274 }
275 }
276 }
277}
278
279/**
280 * qcom_smp2p_intr() - interrupt handler for incoming notifications
281 * @irq: unused
282 * @data: smp2p driver context
283 *
284 * Handle notifications from the remote side to handle newly allocated entries
285 * or any changes to the state bits of existing entries.
286 *
287 * Return: %IRQ_HANDLED
288 */
289static irqreturn_t qcom_smp2p_intr(int irq, void *data)
290{
291 struct smp2p_smem_item *in;
292 struct qcom_smp2p *smp2p = data;
293 unsigned int smem_id = smp2p->smem_items[SMP2P_INBOUND];
294 unsigned int pid = smp2p->remote_pid;
295 bool ack_restart;
296 size_t size;
297
298 in = smp2p->in;
299
300 /* Acquire smem item, if not already found */
301 if (!in) {
302 in = qcom_smem_get(pid, smem_id, &size);
303 if (IS_ERR(in)) {
304 dev_err(smp2p->dev,
305 "Unable to acquire remote smp2p item\n");
306 goto out;
307 }
308
309 smp2p->in = in;
310 }
311
312 if (!smp2p->negotiation_done)
313 qcom_smp2p_negotiate(smp2p);
314
315 if (smp2p->negotiation_done) {
316 ack_restart = qcom_smp2p_check_ssr(smp2p);
317 qcom_smp2p_notify_in(smp2p);
318
319 if (ack_restart)
320 qcom_smp2p_do_ssr_ack(smp2p);
321 }
322
323out:
324 return IRQ_HANDLED;
325}
326
327static void smp2p_mask_irq(struct irq_data *irqd)
328{
329 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
330 irq_hw_number_t irq = irqd_to_hwirq(irqd);
331
332 clear_bit(irq, entry->irq_enabled);
333}
334
335static void smp2p_unmask_irq(struct irq_data *irqd)
336{
337 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
338 irq_hw_number_t irq = irqd_to_hwirq(irqd);
339
340 set_bit(irq, entry->irq_enabled);
341}
342
343static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)
344{
345 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
346 irq_hw_number_t irq = irqd_to_hwirq(irqd);
347
348 if (!(type & IRQ_TYPE_EDGE_BOTH))
349 return -EINVAL;
350
351 if (type & IRQ_TYPE_EDGE_RISING)
352 set_bit(irq, entry->irq_rising);
353 else
354 clear_bit(irq, entry->irq_rising);
355
356 if (type & IRQ_TYPE_EDGE_FALLING)
357 set_bit(irq, entry->irq_falling);
358 else
359 clear_bit(irq, entry->irq_falling);
360
361 return 0;
362}
363
364static void smp2p_irq_print_chip(struct irq_data *irqd, struct seq_file *p)
365{
366 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
367
368 seq_printf(p, "%8s", dev_name(entry->smp2p->dev));
369}
370
371static struct irq_chip smp2p_irq_chip = {
372 .name = "smp2p",
373 .irq_mask = smp2p_mask_irq,
374 .irq_unmask = smp2p_unmask_irq,
375 .irq_set_type = smp2p_set_irq_type,
376 .irq_print_chip = smp2p_irq_print_chip,
377};
378
379static int smp2p_irq_map(struct irq_domain *d,
380 unsigned int irq,
381 irq_hw_number_t hw)
382{
383 struct smp2p_entry *entry = d->host_data;
384
385 irq_set_chip_and_handler(irq, &smp2p_irq_chip, handle_level_irq);
386 irq_set_chip_data(irq, entry);
387 irq_set_nested_thread(irq, 1);
388 irq_set_noprobe(irq);
389
390 return 0;
391}
392
393static const struct irq_domain_ops smp2p_irq_ops = {
394 .map = smp2p_irq_map,
395 .xlate = irq_domain_xlate_twocell,
396};
397
398static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
399 struct smp2p_entry *entry,
400 struct device_node *node)
401{
402 entry->domain = irq_domain_add_linear(node, 32, &smp2p_irq_ops, entry);
403 if (!entry->domain) {
404 dev_err(smp2p->dev, "failed to add irq_domain\n");
405 return -ENOMEM;
406 }
407
408 return 0;
409}
410
411static int smp2p_update_bits(void *data, u32 mask, u32 value)
412{
413 struct smp2p_entry *entry = data;
414 unsigned long flags;
415 u32 orig;
416 u32 val;
417
418 spin_lock_irqsave(&entry->lock, flags);
419 val = orig = readl(entry->value);
420 val &= ~mask;
421 val |= value;
422 writel(val, entry->value);
423 spin_unlock_irqrestore(&entry->lock, flags);
424
425 trace_smp2p_update_bits(entry, orig, val);
426
427 if (val != orig)
428 qcom_smp2p_kick(entry->smp2p);
429
430 return 0;
431}
432
433static const struct qcom_smem_state_ops smp2p_state_ops = {
434 .update_bits = smp2p_update_bits,
435};
436
437static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
438 struct smp2p_entry *entry,
439 struct device_node *node)
440{
441 struct smp2p_smem_item *out = smp2p->out;
442 char buf[SMP2P_MAX_ENTRY_NAME] = {};
443
444 /* Allocate an entry from the smem item */
445 strscpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
446 memcpy(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
447
448 /* Make the logical entry reference the physical value */
449 entry->value = &out->entries[out->valid_entries].value;
450
451 out->valid_entries++;
452
453 entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);
454 if (IS_ERR(entry->state)) {
455 dev_err(smp2p->dev, "failed to register qcom_smem_state\n");
456 return PTR_ERR(entry->state);
457 }
458
459 return 0;
460}
461
462static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
463{
464 struct smp2p_smem_item *out;
465 unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
466 unsigned pid = smp2p->remote_pid;
467 int ret;
468
469 ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));
470 if (ret < 0 && ret != -EEXIST)
471 return dev_err_probe(smp2p->dev, ret,
472 "unable to allocate local smp2p item\n");
473
474 out = qcom_smem_get(pid, smem_id, NULL);
475 if (IS_ERR(out)) {
476 dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");
477 return PTR_ERR(out);
478 }
479
480 memset(out, 0, sizeof(*out));
481 out->magic = SMP2P_MAGIC;
482 out->local_pid = smp2p->local_pid;
483 out->remote_pid = smp2p->remote_pid;
484 out->total_entries = SMP2P_MAX_ENTRY;
485 out->valid_entries = 0;
486 out->features = SMP2P_ALL_FEATURES;
487
488 /*
489 * Make sure the rest of the header is written before we validate the
490 * item by writing a valid version number.
491 */
492 wmb();
493 out->version = 1;
494
495 qcom_smp2p_kick(smp2p);
496
497 smp2p->out = out;
498
499 return 0;
500}
501
502static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)
503{
504 struct device_node *syscon;
505 struct device *dev = smp2p->dev;
506 const char *key;
507 int ret;
508
509 syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0);
510 if (!syscon) {
511 dev_err(dev, "no qcom,ipc node\n");
512 return -ENODEV;
513 }
514
515 smp2p->ipc_regmap = syscon_node_to_regmap(syscon);
516 of_node_put(syscon);
517 if (IS_ERR(smp2p->ipc_regmap))
518 return PTR_ERR(smp2p->ipc_regmap);
519
520 key = "qcom,ipc";
521 ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset);
522 if (ret < 0) {
523 dev_err(dev, "no offset in %s\n", key);
524 return -EINVAL;
525 }
526
527 ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit);
528 if (ret < 0) {
529 dev_err(dev, "no bit in %s\n", key);
530 return -EINVAL;
531 }
532
533 return 0;
534}
535
536static int qcom_smp2p_probe(struct platform_device *pdev)
537{
538 struct smp2p_entry *entry;
539 struct qcom_smp2p *smp2p;
540 const char *key;
541 int irq;
542 int ret;
543
544 smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL);
545 if (!smp2p)
546 return -ENOMEM;
547
548 smp2p->dev = &pdev->dev;
549 INIT_LIST_HEAD(&smp2p->inbound);
550 INIT_LIST_HEAD(&smp2p->outbound);
551
552 platform_set_drvdata(pdev, smp2p);
553
554 key = "qcom,smem";
555 ret = of_property_read_u32_array(pdev->dev.of_node, key,
556 smp2p->smem_items, 2);
557 if (ret)
558 return ret;
559
560 key = "qcom,local-pid";
561 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);
562 if (ret)
563 goto report_read_failure;
564
565 key = "qcom,remote-pid";
566 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
567 if (ret)
568 goto report_read_failure;
569
570 irq = platform_get_irq(pdev, 0);
571 if (irq < 0)
572 return irq;
573
574 smp2p->mbox_client.dev = &pdev->dev;
575 smp2p->mbox_client.knows_txdone = true;
576 smp2p->mbox_chan = mbox_request_channel(&smp2p->mbox_client, 0);
577 if (IS_ERR(smp2p->mbox_chan)) {
578 if (PTR_ERR(smp2p->mbox_chan) != -ENODEV)
579 return PTR_ERR(smp2p->mbox_chan);
580
581 smp2p->mbox_chan = NULL;
582
583 ret = smp2p_parse_ipc(smp2p);
584 if (ret)
585 return ret;
586 }
587
588 ret = qcom_smp2p_alloc_outbound_item(smp2p);
589 if (ret < 0)
590 goto release_mbox;
591
592 for_each_available_child_of_node_scoped(pdev->dev.of_node, node) {
593 entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);
594 if (!entry) {
595 ret = -ENOMEM;
596 goto unwind_interfaces;
597 }
598
599 entry->smp2p = smp2p;
600 spin_lock_init(&entry->lock);
601
602 ret = of_property_read_string(node, "qcom,entry-name", &entry->name);
603 if (ret < 0)
604 goto unwind_interfaces;
605
606 if (of_property_read_bool(node, "interrupt-controller")) {
607 ret = qcom_smp2p_inbound_entry(smp2p, entry, node);
608 if (ret < 0)
609 goto unwind_interfaces;
610
611 list_add(&entry->node, &smp2p->inbound);
612 } else {
613 ret = qcom_smp2p_outbound_entry(smp2p, entry, node);
614 if (ret < 0)
615 goto unwind_interfaces;
616
617 list_add(&entry->node, &smp2p->outbound);
618 }
619 }
620
621 /* Kick the outgoing edge after allocating entries */
622 qcom_smp2p_kick(smp2p);
623
624 ret = devm_request_threaded_irq(&pdev->dev, irq,
625 NULL, qcom_smp2p_intr,
626 IRQF_ONESHOT,
627 NULL, (void *)smp2p);
628 if (ret) {
629 dev_err(&pdev->dev, "failed to request interrupt\n");
630 goto unwind_interfaces;
631 }
632
633 /*
634 * Treat smp2p interrupt as wakeup source, but keep it disabled
635 * by default. User space can decide enabling it depending on its
636 * use cases. For example if remoteproc crashes and device wants
637 * to handle it immediatedly (e.g. to not miss phone calls) it can
638 * enable wakeup source from user space, while other devices which
639 * do not have proper autosleep feature may want to handle it with
640 * other wakeup events (e.g. Power button) instead waking up immediately.
641 */
642 device_set_wakeup_capable(&pdev->dev, true);
643
644 ret = dev_pm_set_wake_irq(&pdev->dev, irq);
645 if (ret)
646 goto set_wake_irq_fail;
647
648 return 0;
649
650set_wake_irq_fail:
651 dev_pm_clear_wake_irq(&pdev->dev);
652
653unwind_interfaces:
654 list_for_each_entry(entry, &smp2p->inbound, node)
655 irq_domain_remove(entry->domain);
656
657 list_for_each_entry(entry, &smp2p->outbound, node)
658 qcom_smem_state_unregister(entry->state);
659
660 smp2p->out->valid_entries = 0;
661
662release_mbox:
663 mbox_free_channel(smp2p->mbox_chan);
664
665 return ret;
666
667report_read_failure:
668 dev_err(&pdev->dev, "failed to read %s\n", key);
669 return -EINVAL;
670}
671
672static void qcom_smp2p_remove(struct platform_device *pdev)
673{
674 struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);
675 struct smp2p_entry *entry;
676
677 dev_pm_clear_wake_irq(&pdev->dev);
678
679 list_for_each_entry(entry, &smp2p->inbound, node)
680 irq_domain_remove(entry->domain);
681
682 list_for_each_entry(entry, &smp2p->outbound, node)
683 qcom_smem_state_unregister(entry->state);
684
685 mbox_free_channel(smp2p->mbox_chan);
686
687 smp2p->out->valid_entries = 0;
688}
689
690static const struct of_device_id qcom_smp2p_of_match[] = {
691 { .compatible = "qcom,smp2p" },
692 {}
693};
694MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match);
695
696static struct platform_driver qcom_smp2p_driver = {
697 .probe = qcom_smp2p_probe,
698 .remove = qcom_smp2p_remove,
699 .driver = {
700 .name = "qcom_smp2p",
701 .of_match_table = qcom_smp2p_of_match,
702 },
703};
704module_platform_driver(qcom_smp2p_driver);
705
706MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver");
707MODULE_LICENSE("GPL v2");