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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/*
2 * Copyright (c) 2015, Sony Mobile Communications AB.
3 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 and
7 * only version 2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15#include <linux/interrupt.h>
16#include <linux/list.h>
17#include <linux/io.h>
18#include <linux/of.h>
19#include <linux/irq.h>
20#include <linux/irqdomain.h>
21#include <linux/mfd/syscon.h>
22#include <linux/module.h>
23#include <linux/platform_device.h>
24#include <linux/regmap.h>
25#include <linux/soc/qcom/smem.h>
26#include <linux/soc/qcom/smem_state.h>
27#include <linux/spinlock.h>
28
29/*
30 * The Shared Memory Point to Point (SMP2P) protocol facilitates communication
31 * of a single 32-bit value between two processors. Each value has a single
32 * writer (the local side) and a single reader (the remote side). Values are
33 * uniquely identified in the system by the directed edge (local processor ID
34 * to remote processor ID) and a string identifier.
35 *
36 * Each processor is responsible for creating the outgoing SMEM items and each
37 * item is writable by the local processor and readable by the remote
38 * processor. By using two separate SMEM items that are single-reader and
39 * single-writer, SMP2P does not require any remote locking mechanisms.
40 *
41 * The driver uses the Linux GPIO and interrupt framework to expose a virtual
42 * GPIO for each outbound entry and a virtual interrupt controller for each
43 * inbound entry.
44 */
45
46#define SMP2P_MAX_ENTRY 16
47#define SMP2P_MAX_ENTRY_NAME 16
48
49#define SMP2P_FEATURE_SSR_ACK 0x1
50
51#define SMP2P_MAGIC 0x504d5324
52
53/**
54 * struct smp2p_smem_item - in memory communication structure
55 * @magic: magic number
56 * @version: version - must be 1
57 * @features: features flag - currently unused
58 * @local_pid: processor id of sending end
59 * @remote_pid: processor id of receiving end
60 * @total_entries: number of entries - always SMP2P_MAX_ENTRY
61 * @valid_entries: number of allocated entries
62 * @flags:
63 * @entries: individual communication entries
64 * @name: name of the entry
65 * @value: content of the entry
66 */
67struct smp2p_smem_item {
68 u32 magic;
69 u8 version;
70 unsigned features:24;
71 u16 local_pid;
72 u16 remote_pid;
73 u16 total_entries;
74 u16 valid_entries;
75 u32 flags;
76
77 struct {
78 u8 name[SMP2P_MAX_ENTRY_NAME];
79 u32 value;
80 } entries[SMP2P_MAX_ENTRY];
81} __packed;
82
83/**
84 * struct smp2p_entry - driver context matching one entry
85 * @node: list entry to keep track of allocated entries
86 * @smp2p: reference to the device driver context
87 * @name: name of the entry, to match against smp2p_smem_item
88 * @value: pointer to smp2p_smem_item entry value
89 * @last_value: last handled value
90 * @domain: irq_domain for inbound entries
91 * @irq_enabled:bitmap to track enabled irq bits
92 * @irq_rising: bitmap to mark irq bits for rising detection
93 * @irq_falling:bitmap to mark irq bits for falling detection
94 * @state: smem state handle
95 * @lock: spinlock to protect read-modify-write of the value
96 */
97struct smp2p_entry {
98 struct list_head node;
99 struct qcom_smp2p *smp2p;
100
101 const char *name;
102 u32 *value;
103 u32 last_value;
104
105 struct irq_domain *domain;
106 DECLARE_BITMAP(irq_enabled, 32);
107 DECLARE_BITMAP(irq_rising, 32);
108 DECLARE_BITMAP(irq_falling, 32);
109
110 struct qcom_smem_state *state;
111
112 spinlock_t lock;
113};
114
115#define SMP2P_INBOUND 0
116#define SMP2P_OUTBOUND 1
117
118/**
119 * struct qcom_smp2p - device driver context
120 * @dev: device driver handle
121 * @in: pointer to the inbound smem item
122 * @smem_items: ids of the two smem items
123 * @valid_entries: already scanned inbound entries
124 * @local_pid: processor id of the inbound edge
125 * @remote_pid: processor id of the outbound edge
126 * @ipc_regmap: regmap for the outbound ipc
127 * @ipc_offset: offset within the regmap
128 * @ipc_bit: bit in regmap@offset to kick to signal remote processor
129 * @inbound: list of inbound entries
130 * @outbound: list of outbound entries
131 */
132struct qcom_smp2p {
133 struct device *dev;
134
135 struct smp2p_smem_item *in;
136 struct smp2p_smem_item *out;
137
138 unsigned smem_items[SMP2P_OUTBOUND + 1];
139
140 unsigned valid_entries;
141
142 unsigned local_pid;
143 unsigned remote_pid;
144
145 struct regmap *ipc_regmap;
146 int ipc_offset;
147 int ipc_bit;
148
149 struct list_head inbound;
150 struct list_head outbound;
151};
152
153static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
154{
155 /* Make sure any updated data is written before the kick */
156 wmb();
157 regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
158}
159
160/**
161 * qcom_smp2p_intr() - interrupt handler for incoming notifications
162 * @irq: unused
163 * @data: smp2p driver context
164 *
165 * Handle notifications from the remote side to handle newly allocated entries
166 * or any changes to the state bits of existing entries.
167 */
168static irqreturn_t qcom_smp2p_intr(int irq, void *data)
169{
170 struct smp2p_smem_item *in;
171 struct smp2p_entry *entry;
172 struct qcom_smp2p *smp2p = data;
173 unsigned smem_id = smp2p->smem_items[SMP2P_INBOUND];
174 unsigned pid = smp2p->remote_pid;
175 size_t size;
176 int irq_pin;
177 u32 status;
178 char buf[SMP2P_MAX_ENTRY_NAME];
179 u32 val;
180 int i;
181
182 in = smp2p->in;
183
184 /* Acquire smem item, if not already found */
185 if (!in) {
186 in = qcom_smem_get(pid, smem_id, &size);
187 if (IS_ERR(in)) {
188 dev_err(smp2p->dev,
189 "Unable to acquire remote smp2p item\n");
190 return IRQ_HANDLED;
191 }
192
193 smp2p->in = in;
194 }
195
196 /* Match newly created entries */
197 for (i = smp2p->valid_entries; i < in->valid_entries; i++) {
198 list_for_each_entry(entry, &smp2p->inbound, node) {
199 memcpy_fromio(buf, in->entries[i].name, sizeof(buf));
200 if (!strcmp(buf, entry->name)) {
201 entry->value = &in->entries[i].value;
202 break;
203 }
204 }
205 }
206 smp2p->valid_entries = i;
207
208 /* Fire interrupts based on any value changes */
209 list_for_each_entry(entry, &smp2p->inbound, node) {
210 /* Ignore entries not yet allocated by the remote side */
211 if (!entry->value)
212 continue;
213
214 val = readl(entry->value);
215
216 status = val ^ entry->last_value;
217 entry->last_value = val;
218
219 /* No changes of this entry? */
220 if (!status)
221 continue;
222
223 for_each_set_bit(i, entry->irq_enabled, 32) {
224 if (!(status & BIT(i)))
225 continue;
226
227 if ((val & BIT(i) && test_bit(i, entry->irq_rising)) ||
228 (!(val & BIT(i)) && test_bit(i, entry->irq_falling))) {
229 irq_pin = irq_find_mapping(entry->domain, i);
230 handle_nested_irq(irq_pin);
231 }
232 }
233 }
234
235 return IRQ_HANDLED;
236}
237
238static void smp2p_mask_irq(struct irq_data *irqd)
239{
240 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
241 irq_hw_number_t irq = irqd_to_hwirq(irqd);
242
243 clear_bit(irq, entry->irq_enabled);
244}
245
246static void smp2p_unmask_irq(struct irq_data *irqd)
247{
248 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
249 irq_hw_number_t irq = irqd_to_hwirq(irqd);
250
251 set_bit(irq, entry->irq_enabled);
252}
253
254static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)
255{
256 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
257 irq_hw_number_t irq = irqd_to_hwirq(irqd);
258
259 if (!(type & IRQ_TYPE_EDGE_BOTH))
260 return -EINVAL;
261
262 if (type & IRQ_TYPE_EDGE_RISING)
263 set_bit(irq, entry->irq_rising);
264 else
265 clear_bit(irq, entry->irq_rising);
266
267 if (type & IRQ_TYPE_EDGE_FALLING)
268 set_bit(irq, entry->irq_falling);
269 else
270 clear_bit(irq, entry->irq_falling);
271
272 return 0;
273}
274
275static struct irq_chip smp2p_irq_chip = {
276 .name = "smp2p",
277 .irq_mask = smp2p_mask_irq,
278 .irq_unmask = smp2p_unmask_irq,
279 .irq_set_type = smp2p_set_irq_type,
280};
281
282static int smp2p_irq_map(struct irq_domain *d,
283 unsigned int irq,
284 irq_hw_number_t hw)
285{
286 struct smp2p_entry *entry = d->host_data;
287
288 irq_set_chip_and_handler(irq, &smp2p_irq_chip, handle_level_irq);
289 irq_set_chip_data(irq, entry);
290 irq_set_nested_thread(irq, 1);
291 irq_set_noprobe(irq);
292
293 return 0;
294}
295
296static const struct irq_domain_ops smp2p_irq_ops = {
297 .map = smp2p_irq_map,
298 .xlate = irq_domain_xlate_twocell,
299};
300
301static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
302 struct smp2p_entry *entry,
303 struct device_node *node)
304{
305 entry->domain = irq_domain_add_linear(node, 32, &smp2p_irq_ops, entry);
306 if (!entry->domain) {
307 dev_err(smp2p->dev, "failed to add irq_domain\n");
308 return -ENOMEM;
309 }
310
311 return 0;
312}
313
314static int smp2p_update_bits(void *data, u32 mask, u32 value)
315{
316 struct smp2p_entry *entry = data;
317 u32 orig;
318 u32 val;
319
320 spin_lock(&entry->lock);
321 val = orig = readl(entry->value);
322 val &= ~mask;
323 val |= value;
324 writel(val, entry->value);
325 spin_unlock(&entry->lock);
326
327 if (val != orig)
328 qcom_smp2p_kick(entry->smp2p);
329
330 return 0;
331}
332
333static const struct qcom_smem_state_ops smp2p_state_ops = {
334 .update_bits = smp2p_update_bits,
335};
336
337static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
338 struct smp2p_entry *entry,
339 struct device_node *node)
340{
341 struct smp2p_smem_item *out = smp2p->out;
342 char buf[SMP2P_MAX_ENTRY_NAME] = {};
343
344 /* Allocate an entry from the smem item */
345 strlcpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
346 memcpy_toio(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
347 out->valid_entries++;
348
349 /* Make the logical entry reference the physical value */
350 entry->value = &out->entries[out->valid_entries].value;
351
352 entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);
353 if (IS_ERR(entry->state)) {
354 dev_err(smp2p->dev, "failed to register qcom_smem_state\n");
355 return PTR_ERR(entry->state);
356 }
357
358 return 0;
359}
360
361static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
362{
363 struct smp2p_smem_item *out;
364 unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
365 unsigned pid = smp2p->remote_pid;
366 int ret;
367
368 ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));
369 if (ret < 0 && ret != -EEXIST) {
370 if (ret != -EPROBE_DEFER)
371 dev_err(smp2p->dev,
372 "unable to allocate local smp2p item\n");
373 return ret;
374 }
375
376 out = qcom_smem_get(pid, smem_id, NULL);
377 if (IS_ERR(out)) {
378 dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");
379 return PTR_ERR(out);
380 }
381
382 memset(out, 0, sizeof(*out));
383 out->magic = SMP2P_MAGIC;
384 out->local_pid = smp2p->local_pid;
385 out->remote_pid = smp2p->remote_pid;
386 out->total_entries = SMP2P_MAX_ENTRY;
387 out->valid_entries = 0;
388
389 /*
390 * Make sure the rest of the header is written before we validate the
391 * item by writing a valid version number.
392 */
393 wmb();
394 out->version = 1;
395
396 qcom_smp2p_kick(smp2p);
397
398 smp2p->out = out;
399
400 return 0;
401}
402
403static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)
404{
405 struct device_node *syscon;
406 struct device *dev = smp2p->dev;
407 const char *key;
408 int ret;
409
410 syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0);
411 if (!syscon) {
412 dev_err(dev, "no qcom,ipc node\n");
413 return -ENODEV;
414 }
415
416 smp2p->ipc_regmap = syscon_node_to_regmap(syscon);
417 if (IS_ERR(smp2p->ipc_regmap))
418 return PTR_ERR(smp2p->ipc_regmap);
419
420 key = "qcom,ipc";
421 ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset);
422 if (ret < 0) {
423 dev_err(dev, "no offset in %s\n", key);
424 return -EINVAL;
425 }
426
427 ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit);
428 if (ret < 0) {
429 dev_err(dev, "no bit in %s\n", key);
430 return -EINVAL;
431 }
432
433 return 0;
434}
435
436static int qcom_smp2p_probe(struct platform_device *pdev)
437{
438 struct smp2p_entry *entry;
439 struct device_node *node;
440 struct qcom_smp2p *smp2p;
441 const char *key;
442 int irq;
443 int ret;
444
445 smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL);
446 if (!smp2p)
447 return -ENOMEM;
448
449 smp2p->dev = &pdev->dev;
450 INIT_LIST_HEAD(&smp2p->inbound);
451 INIT_LIST_HEAD(&smp2p->outbound);
452
453 platform_set_drvdata(pdev, smp2p);
454
455 ret = smp2p_parse_ipc(smp2p);
456 if (ret)
457 return ret;
458
459 key = "qcom,smem";
460 ret = of_property_read_u32_array(pdev->dev.of_node, key,
461 smp2p->smem_items, 2);
462 if (ret)
463 return ret;
464
465 key = "qcom,local-pid";
466 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);
467 if (ret < 0) {
468 dev_err(&pdev->dev, "failed to read %s\n", key);
469 return -EINVAL;
470 }
471
472 key = "qcom,remote-pid";
473 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
474 if (ret < 0) {
475 dev_err(&pdev->dev, "failed to read %s\n", key);
476 return -EINVAL;
477 }
478
479 irq = platform_get_irq(pdev, 0);
480 if (irq < 0) {
481 dev_err(&pdev->dev, "unable to acquire smp2p interrupt\n");
482 return irq;
483 }
484
485 ret = qcom_smp2p_alloc_outbound_item(smp2p);
486 if (ret < 0)
487 return ret;
488
489 for_each_available_child_of_node(pdev->dev.of_node, node) {
490 entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);
491 if (!entry) {
492 ret = -ENOMEM;
493 goto unwind_interfaces;
494 }
495
496 entry->smp2p = smp2p;
497 spin_lock_init(&entry->lock);
498
499 ret = of_property_read_string(node, "qcom,entry-name", &entry->name);
500 if (ret < 0)
501 goto unwind_interfaces;
502
503 if (of_property_read_bool(node, "interrupt-controller")) {
504 ret = qcom_smp2p_inbound_entry(smp2p, entry, node);
505 if (ret < 0)
506 goto unwind_interfaces;
507
508 list_add(&entry->node, &smp2p->inbound);
509 } else {
510 ret = qcom_smp2p_outbound_entry(smp2p, entry, node);
511 if (ret < 0)
512 goto unwind_interfaces;
513
514 list_add(&entry->node, &smp2p->outbound);
515 }
516 }
517
518 /* Kick the outgoing edge after allocating entries */
519 qcom_smp2p_kick(smp2p);
520
521 ret = devm_request_threaded_irq(&pdev->dev, irq,
522 NULL, qcom_smp2p_intr,
523 IRQF_ONESHOT,
524 "smp2p", (void *)smp2p);
525 if (ret) {
526 dev_err(&pdev->dev, "failed to request interrupt\n");
527 goto unwind_interfaces;
528 }
529
530
531 return 0;
532
533unwind_interfaces:
534 list_for_each_entry(entry, &smp2p->inbound, node)
535 irq_domain_remove(entry->domain);
536
537 list_for_each_entry(entry, &smp2p->outbound, node)
538 qcom_smem_state_unregister(entry->state);
539
540 smp2p->out->valid_entries = 0;
541
542 return ret;
543}
544
545static int qcom_smp2p_remove(struct platform_device *pdev)
546{
547 struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);
548 struct smp2p_entry *entry;
549
550 list_for_each_entry(entry, &smp2p->inbound, node)
551 irq_domain_remove(entry->domain);
552
553 list_for_each_entry(entry, &smp2p->outbound, node)
554 qcom_smem_state_unregister(entry->state);
555
556 smp2p->out->valid_entries = 0;
557
558 return 0;
559}
560
561static const struct of_device_id qcom_smp2p_of_match[] = {
562 { .compatible = "qcom,smp2p" },
563 {}
564};
565MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match);
566
567static struct platform_driver qcom_smp2p_driver = {
568 .probe = qcom_smp2p_probe,
569 .remove = qcom_smp2p_remove,
570 .driver = {
571 .name = "qcom_smp2p",
572 .of_match_table = qcom_smp2p_of_match,
573 },
574};
575module_platform_driver(qcom_smp2p_driver);
576
577MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver");
578MODULE_LICENSE("GPL v2");