1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2015, Sony Mobile Communications AB.
4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
7 #include <linux/interrupt.h>
8 #include <linux/list.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>
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.
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.
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
39 #define SMP2P_MAX_ENTRY 16
40 #define SMP2P_MAX_ENTRY_NAME 16
42 #define SMP2P_FEATURE_SSR_ACK 0x1
44 #define SMP2P_MAGIC 0x504d5324
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
56 * @entries: individual communication entries
57 * @name: name of the entry
58 * @value: content of the entry
60 struct smp2p_smem_item {
71 u8 name[SMP2P_MAX_ENTRY_NAME];
73 } entries[SMP2P_MAX_ENTRY];
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
91 struct list_head node;
92 struct qcom_smp2p *smp2p;
98 struct irq_domain *domain;
99 DECLARE_BITMAP(irq_enabled, 32);
100 DECLARE_BITMAP(irq_rising, 32);
101 DECLARE_BITMAP(irq_falling, 32);
103 struct qcom_smem_state *state;
108 #define SMP2P_INBOUND 0
109 #define SMP2P_OUTBOUND 1
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
130 struct smp2p_smem_item *in;
131 struct smp2p_smem_item *out;
133 unsigned smem_items[SMP2P_OUTBOUND + 1];
135 unsigned valid_entries;
140 struct regmap *ipc_regmap;
144 struct mbox_client mbox_client;
145 struct mbox_chan *mbox_chan;
147 struct list_head inbound;
148 struct list_head outbound;
151 static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
153 /* Make sure any updated data is written before the kick */
156 if (smp2p->mbox_chan) {
157 mbox_send_message(smp2p->mbox_chan, NULL);
158 mbox_client_txdone(smp2p->mbox_chan, 0);
160 regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit));
165 * qcom_smp2p_intr() - interrupt handler for incoming notifications
167 * @data: smp2p driver context
169 * Handle notifications from the remote side to handle newly allocated entries
170 * or any changes to the state bits of existing entries.
172 static irqreturn_t qcom_smp2p_intr(int irq, void *data)
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;
182 char buf[SMP2P_MAX_ENTRY_NAME];
188 /* Acquire smem item, if not already found */
190 in = qcom_smem_get(pid, smem_id, &size);
193 "Unable to acquire remote smp2p item\n");
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;
210 smp2p->valid_entries = i;
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 */
218 val = readl(entry->value);
220 status = val ^ entry->last_value;
221 entry->last_value = val;
223 /* No changes of this entry? */
227 for_each_set_bit(i, entry->irq_enabled, 32) {
228 if (!(status & BIT(i)))
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);
242 static void smp2p_mask_irq(struct irq_data *irqd)
244 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
245 irq_hw_number_t irq = irqd_to_hwirq(irqd);
247 clear_bit(irq, entry->irq_enabled);
250 static void smp2p_unmask_irq(struct irq_data *irqd)
252 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
253 irq_hw_number_t irq = irqd_to_hwirq(irqd);
255 set_bit(irq, entry->irq_enabled);
258 static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type)
260 struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd);
261 irq_hw_number_t irq = irqd_to_hwirq(irqd);
263 if (!(type & IRQ_TYPE_EDGE_BOTH))
266 if (type & IRQ_TYPE_EDGE_RISING)
267 set_bit(irq, entry->irq_rising);
269 clear_bit(irq, entry->irq_rising);
271 if (type & IRQ_TYPE_EDGE_FALLING)
272 set_bit(irq, entry->irq_falling);
274 clear_bit(irq, entry->irq_falling);
279 static struct irq_chip smp2p_irq_chip = {
281 .irq_mask = smp2p_mask_irq,
282 .irq_unmask = smp2p_unmask_irq,
283 .irq_set_type = smp2p_set_irq_type,
286 static int smp2p_irq_map(struct irq_domain *d,
290 struct smp2p_entry *entry = d->host_data;
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);
300 static const struct irq_domain_ops smp2p_irq_ops = {
301 .map = smp2p_irq_map,
302 .xlate = irq_domain_xlate_twocell,
305 static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p,
306 struct smp2p_entry *entry,
307 struct device_node *node)
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");
318 static int smp2p_update_bits(void *data, u32 mask, u32 value)
320 struct smp2p_entry *entry = data;
325 spin_lock_irqsave(&entry->lock, flags);
326 val = orig = readl(entry->value);
329 writel(val, entry->value);
330 spin_unlock_irqrestore(&entry->lock, flags);
333 qcom_smp2p_kick(entry->smp2p);
338 static const struct qcom_smem_state_ops smp2p_state_ops = {
339 .update_bits = smp2p_update_bits,
342 static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p,
343 struct smp2p_entry *entry,
344 struct device_node *node)
346 struct smp2p_smem_item *out = smp2p->out;
347 char buf[SMP2P_MAX_ENTRY_NAME] = {};
349 /* Allocate an entry from the smem item */
350 strlcpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME);
351 memcpy(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME);
353 /* Make the logical entry reference the physical value */
354 entry->value = &out->entries[out->valid_entries].value;
356 out->valid_entries++;
358 entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry);
359 if (IS_ERR(entry->state)) {
360 dev_err(smp2p->dev, "failed to register qcom_smem_state\n");
361 return PTR_ERR(entry->state);
367 static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p)
369 struct smp2p_smem_item *out;
370 unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND];
371 unsigned pid = smp2p->remote_pid;
374 ret = qcom_smem_alloc(pid, smem_id, sizeof(*out));
375 if (ret < 0 && ret != -EEXIST) {
376 if (ret != -EPROBE_DEFER)
378 "unable to allocate local smp2p item\n");
382 out = qcom_smem_get(pid, smem_id, NULL);
384 dev_err(smp2p->dev, "Unable to acquire local smp2p item\n");
388 memset(out, 0, sizeof(*out));
389 out->magic = SMP2P_MAGIC;
390 out->local_pid = smp2p->local_pid;
391 out->remote_pid = smp2p->remote_pid;
392 out->total_entries = SMP2P_MAX_ENTRY;
393 out->valid_entries = 0;
396 * Make sure the rest of the header is written before we validate the
397 * item by writing a valid version number.
402 qcom_smp2p_kick(smp2p);
409 static int smp2p_parse_ipc(struct qcom_smp2p *smp2p)
411 struct device_node *syscon;
412 struct device *dev = smp2p->dev;
416 syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0);
418 dev_err(dev, "no qcom,ipc node\n");
422 smp2p->ipc_regmap = syscon_node_to_regmap(syscon);
424 if (IS_ERR(smp2p->ipc_regmap))
425 return PTR_ERR(smp2p->ipc_regmap);
428 ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset);
430 dev_err(dev, "no offset in %s\n", key);
434 ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit);
436 dev_err(dev, "no bit in %s\n", key);
443 static int qcom_smp2p_probe(struct platform_device *pdev)
445 struct smp2p_entry *entry;
446 struct device_node *node;
447 struct qcom_smp2p *smp2p;
452 smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL);
456 smp2p->dev = &pdev->dev;
457 INIT_LIST_HEAD(&smp2p->inbound);
458 INIT_LIST_HEAD(&smp2p->outbound);
460 platform_set_drvdata(pdev, smp2p);
463 ret = of_property_read_u32_array(pdev->dev.of_node, key,
464 smp2p->smem_items, 2);
468 key = "qcom,local-pid";
469 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid);
471 goto report_read_failure;
473 key = "qcom,remote-pid";
474 ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid);
476 goto report_read_failure;
478 irq = platform_get_irq(pdev, 0);
482 smp2p->mbox_client.dev = &pdev->dev;
483 smp2p->mbox_client.knows_txdone = true;
484 smp2p->mbox_chan = mbox_request_channel(&smp2p->mbox_client, 0);
485 if (IS_ERR(smp2p->mbox_chan)) {
486 if (PTR_ERR(smp2p->mbox_chan) != -ENODEV)
487 return PTR_ERR(smp2p->mbox_chan);
489 smp2p->mbox_chan = NULL;
491 ret = smp2p_parse_ipc(smp2p);
496 ret = qcom_smp2p_alloc_outbound_item(smp2p);
500 for_each_available_child_of_node(pdev->dev.of_node, node) {
501 entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL);
504 goto unwind_interfaces;
507 entry->smp2p = smp2p;
508 spin_lock_init(&entry->lock);
510 ret = of_property_read_string(node, "qcom,entry-name", &entry->name);
512 goto unwind_interfaces;
514 if (of_property_read_bool(node, "interrupt-controller")) {
515 ret = qcom_smp2p_inbound_entry(smp2p, entry, node);
517 goto unwind_interfaces;
519 list_add(&entry->node, &smp2p->inbound);
521 ret = qcom_smp2p_outbound_entry(smp2p, entry, node);
523 goto unwind_interfaces;
525 list_add(&entry->node, &smp2p->outbound);
529 /* Kick the outgoing edge after allocating entries */
530 qcom_smp2p_kick(smp2p);
532 ret = devm_request_threaded_irq(&pdev->dev, irq,
533 NULL, qcom_smp2p_intr,
535 "smp2p", (void *)smp2p);
537 dev_err(&pdev->dev, "failed to request interrupt\n");
538 goto unwind_interfaces;
545 list_for_each_entry(entry, &smp2p->inbound, node)
546 irq_domain_remove(entry->domain);
548 list_for_each_entry(entry, &smp2p->outbound, node)
549 qcom_smem_state_unregister(entry->state);
551 smp2p->out->valid_entries = 0;
554 mbox_free_channel(smp2p->mbox_chan);
559 dev_err(&pdev->dev, "failed to read %s\n", key);
563 static int qcom_smp2p_remove(struct platform_device *pdev)
565 struct qcom_smp2p *smp2p = platform_get_drvdata(pdev);
566 struct smp2p_entry *entry;
568 list_for_each_entry(entry, &smp2p->inbound, node)
569 irq_domain_remove(entry->domain);
571 list_for_each_entry(entry, &smp2p->outbound, node)
572 qcom_smem_state_unregister(entry->state);
574 mbox_free_channel(smp2p->mbox_chan);
576 smp2p->out->valid_entries = 0;
581 static const struct of_device_id qcom_smp2p_of_match[] = {
582 { .compatible = "qcom,smp2p" },
585 MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match);
587 static struct platform_driver qcom_smp2p_driver = {
588 .probe = qcom_smp2p_probe,
589 .remove = qcom_smp2p_remove,
591 .name = "qcom_smp2p",
592 .of_match_table = qcom_smp2p_of_match,
595 module_platform_driver(qcom_smp2p_driver);
597 MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver");
598 MODULE_LICENSE("GPL v2");