blob: 08c87fadca8ce610e9baff8706dabe2fb7ac82a4 [file] [log] [blame]
Ashwin Chaugule86c22f82014-11-12 19:59:38 -05001/*
2 * Copyright (C) 2014 Linaro Ltd.
3 * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
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 as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * PCC (Platform Communication Channel) is defined in the ACPI 5.0+
16 * specification. It is a mailbox like mechanism to allow clients
17 * such as CPPC (Collaborative Processor Performance Control), RAS
18 * (Reliability, Availability and Serviceability) and MPST (Memory
19 * Node Power State Table) to talk to the platform (e.g. BMC) through
20 * shared memory regions as defined in the PCC table entries. The PCC
21 * specification supports a Doorbell mechanism for the PCC clients
22 * to notify the platform about new data. This Doorbell information
Ashwin Chaugule33350e62015-01-27 16:03:57 -050023 * is also specified in each PCC table entry.
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050024 *
Ashwin Chaugule33350e62015-01-27 16:03:57 -050025 * Typical high level flow of operation is:
26 *
27 * PCC Reads:
28 * * Client tries to acquire a channel lock.
29 * * After it is acquired it writes READ cmd in communication region cmd
30 * address.
31 * * Client issues mbox_send_message() which rings the PCC doorbell
32 * for its PCC channel.
33 * * If command completes, then client has control over channel and
34 * it can proceed with its reads.
35 * * Client releases lock.
36 *
37 * PCC Writes:
38 * * Client tries to acquire channel lock.
39 * * Client writes to its communication region after it acquires a
40 * channel lock.
41 * * Client writes WRITE cmd in communication region cmd address.
42 * * Client issues mbox_send_message() which rings the PCC doorbell
43 * for its PCC channel.
44 * * If command completes, then writes have succeded and it can release
45 * the channel lock.
46 *
47 * There is a Nominal latency defined for each channel which indicates
48 * how long to wait until a command completes. If command is not complete
49 * the client needs to retry or assume failure.
50 *
51 * For more details about PCC, please see the ACPI specification from
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050052 * http://www.uefi.org/ACPIv5.1 Section 14.
53 *
54 * This file implements PCC as a Mailbox controller and allows for PCC
55 * clients to be implemented as its Mailbox Client Channels.
56 */
57
58#include <linux/acpi.h>
59#include <linux/delay.h>
60#include <linux/io.h>
61#include <linux/init.h>
hotranaca314e2016-08-15 17:14:05 -070062#include <linux/interrupt.h>
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050063#include <linux/list.h>
64#include <linux/platform_device.h>
65#include <linux/mailbox_controller.h>
66#include <linux/mailbox_client.h>
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -070067#include <linux/io-64-nonatomic-lo-hi.h>
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050068
69#include "mailbox.h"
70
71#define MAX_PCC_SUBSPACES 256
hotranaca314e2016-08-15 17:14:05 -070072#define MBOX_IRQ_NAME "pcc-mbox"
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050073
74static struct mbox_chan *pcc_mbox_channels;
75
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -070076/* Array of cached virtual address for doorbell registers */
77static void __iomem **pcc_doorbell_vaddr;
hotranaca314e2016-08-15 17:14:05 -070078/* Array of cached virtual address for doorbell ack registers */
79static void __iomem **pcc_doorbell_ack_vaddr;
80/* Array of doorbell interrupts */
81static int *pcc_doorbell_irq;
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -070082
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050083static struct mbox_controller pcc_mbox_ctrl = {};
84/**
85 * get_pcc_channel - Given a PCC subspace idx, get
86 * the respective mbox_channel.
87 * @id: PCC subspace index.
88 *
89 * Return: ERR_PTR(errno) if error, else pointer
90 * to mbox channel.
91 */
92static struct mbox_chan *get_pcc_channel(int id)
93{
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050094 if (id < 0 || id > pcc_mbox_ctrl.num_chans)
95 return ERR_PTR(-ENOENT);
96
Alexey Klimove9c8dc82015-12-10 17:28:37 +000097 return &pcc_mbox_channels[id];
Ashwin Chaugule86c22f82014-11-12 19:59:38 -050098}
99
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700100/*
101 * PCC can be used with perf critical drivers such as CPPC
102 * So it makes sense to locally cache the virtual address and
103 * use it to read/write to PCC registers such as doorbell register
104 *
105 * The below read_register and write_registers are used to read and
106 * write from perf critical registers such as PCC doorbell register
107 */
108static int read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
109{
110 int ret_val = 0;
111
112 switch (bit_width) {
113 case 8:
114 *val = readb(vaddr);
115 break;
116 case 16:
117 *val = readw(vaddr);
118 break;
119 case 32:
120 *val = readl(vaddr);
121 break;
122 case 64:
123 *val = readq(vaddr);
124 break;
125 default:
126 pr_debug("Error: Cannot read register of %u bit width",
127 bit_width);
128 ret_val = -EFAULT;
129 break;
130 }
131 return ret_val;
132}
133
134static int write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
135{
136 int ret_val = 0;
137
138 switch (bit_width) {
139 case 8:
140 writeb(val, vaddr);
141 break;
142 case 16:
143 writew(val, vaddr);
144 break;
145 case 32:
146 writel(val, vaddr);
147 break;
148 case 64:
149 writeq(val, vaddr);
150 break;
151 default:
152 pr_debug("Error: Cannot write register of %u bit width",
153 bit_width);
154 ret_val = -EFAULT;
155 break;
156 }
157 return ret_val;
158}
159
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500160/**
hotranaca314e2016-08-15 17:14:05 -0700161 * pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number
162 * @interrupt: GSI number.
163 * @flags: interrupt flags
164 *
165 * Returns: a valid linux IRQ number on success
166 * 0 or -EINVAL on failure
167 */
168static int pcc_map_interrupt(u32 interrupt, u32 flags)
169{
170 int trigger, polarity;
171
172 if (!interrupt)
173 return 0;
174
175 trigger = (flags & ACPI_PCCT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
176 : ACPI_LEVEL_SENSITIVE;
177
178 polarity = (flags & ACPI_PCCT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
179 : ACPI_ACTIVE_HIGH;
180
181 return acpi_register_gsi(NULL, interrupt, trigger, polarity);
182}
183
184/**
185 * pcc_mbox_irq - PCC mailbox interrupt handler
186 */
187static irqreturn_t pcc_mbox_irq(int irq, void *p)
188{
189 struct acpi_generic_address *doorbell_ack;
190 struct acpi_pcct_hw_reduced *pcct_ss;
191 struct mbox_chan *chan = p;
192 u64 doorbell_ack_preserve;
193 u64 doorbell_ack_write;
194 u64 doorbell_ack_val;
195 int ret;
196
197 pcct_ss = chan->con_priv;
198
199 mbox_chan_received_data(chan, NULL);
200
201 if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
202 struct acpi_pcct_hw_reduced_type2 *pcct2_ss = chan->con_priv;
203 u32 id = chan - pcc_mbox_channels;
204
205 doorbell_ack = &pcct2_ss->doorbell_ack_register;
206 doorbell_ack_preserve = pcct2_ss->ack_preserve_mask;
207 doorbell_ack_write = pcct2_ss->ack_write_mask;
208
209 ret = read_register(pcc_doorbell_ack_vaddr[id],
210 &doorbell_ack_val,
211 doorbell_ack->bit_width);
212 if (ret)
213 return IRQ_NONE;
214
215 ret = write_register(pcc_doorbell_ack_vaddr[id],
216 (doorbell_ack_val & doorbell_ack_preserve)
217 | doorbell_ack_write,
218 doorbell_ack->bit_width);
219 if (ret)
220 return IRQ_NONE;
221 }
222
223 return IRQ_HANDLED;
224}
225
226/**
227 * pcc_mbox_request_channel - PCC clients call this function to
228 * request a pointer to their PCC subspace, from which they
229 * can get the details of communicating with the remote.
230 * @cl: Pointer to Mailbox client, so we know where to bind the
231 * Channel.
232 * @subspace_id: The PCC Subspace index as parsed in the PCC client
233 * ACPI package. This is used to lookup the array of PCC
234 * subspaces as parsed by the PCC Mailbox controller.
235 *
236 * Return: Pointer to the Mailbox Channel if successful or
237 * ERR_PTR.
238 */
239struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
240 int subspace_id)
241{
242 struct device *dev = pcc_mbox_ctrl.dev;
243 struct mbox_chan *chan;
244 unsigned long flags;
245
246 /*
247 * Each PCC Subspace is a Mailbox Channel.
248 * The PCC Clients get their PCC Subspace ID
249 * from their own tables and pass it here.
250 * This returns a pointer to the PCC subspace
251 * for the Client to operate on.
252 */
253 chan = get_pcc_channel(subspace_id);
254
255 if (IS_ERR(chan) || chan->cl) {
256 dev_err(dev, "Channel not found for idx: %d\n", subspace_id);
257 return ERR_PTR(-EBUSY);
258 }
259
260 spin_lock_irqsave(&chan->lock, flags);
261 chan->msg_free = 0;
262 chan->msg_count = 0;
263 chan->active_req = NULL;
264 chan->cl = cl;
265 init_completion(&chan->tx_complete);
266
267 if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
268 chan->txdone_method |= TXDONE_BY_ACK;
269
270 if (pcc_doorbell_irq[subspace_id] > 0) {
271 int rc;
272
273 rc = devm_request_irq(dev, pcc_doorbell_irq[subspace_id],
274 pcc_mbox_irq, 0, MBOX_IRQ_NAME, chan);
275 if (unlikely(rc)) {
276 dev_err(dev, "failed to register PCC interrupt %d\n",
277 pcc_doorbell_irq[subspace_id]);
278 chan = ERR_PTR(rc);
279 }
280 }
281
282 spin_unlock_irqrestore(&chan->lock, flags);
283
284 return chan;
285}
286EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
287
288/**
289 * pcc_mbox_free_channel - Clients call this to free their Channel.
290 *
291 * @chan: Pointer to the mailbox channel as returned by
292 * pcc_mbox_request_channel()
293 */
294void pcc_mbox_free_channel(struct mbox_chan *chan)
295{
296 u32 id = chan - pcc_mbox_channels;
297 unsigned long flags;
298
299 if (!chan || !chan->cl)
300 return;
301
302 if (id >= pcc_mbox_ctrl.num_chans) {
303 pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n");
304 return;
305 }
306
307 spin_lock_irqsave(&chan->lock, flags);
308 chan->cl = NULL;
309 chan->active_req = NULL;
310 if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
311 chan->txdone_method = TXDONE_BY_POLL;
312
313 if (pcc_doorbell_irq[id] > 0)
314 devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan);
315
316 spin_unlock_irqrestore(&chan->lock, flags);
317}
318EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
319
320
321/**
Ashwin Chaugule33350e62015-01-27 16:03:57 -0500322 * pcc_send_data - Called from Mailbox Controller code. Used
323 * here only to ring the channel doorbell. The PCC client
324 * specific read/write is done in the client driver in
325 * order to maintain atomicity over PCC channel once
326 * OS has control over it. See above for flow of operations.
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500327 * @chan: Pointer to Mailbox channel over which to send data.
Ashwin Chaugule33350e62015-01-27 16:03:57 -0500328 * @data: Client specific data written over channel. Used here
329 * only for debug after PCC transaction completes.
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500330 *
331 * Return: Err if something failed else 0 for success.
332 */
333static int pcc_send_data(struct mbox_chan *chan, void *data)
334{
335 struct acpi_pcct_hw_reduced *pcct_ss = chan->con_priv;
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700336 struct acpi_generic_address *doorbell;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500337 u64 doorbell_preserve;
338 u64 doorbell_val;
339 u64 doorbell_write;
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700340 u32 id = chan - pcc_mbox_channels;
341 int ret = 0;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500342
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700343 if (id >= pcc_mbox_ctrl.num_chans) {
344 pr_debug("pcc_send_data: Invalid mbox_chan passed\n");
345 return -ENOENT;
346 }
347
348 doorbell = &pcct_ss->doorbell_register;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500349 doorbell_preserve = pcct_ss->preserve_mask;
350 doorbell_write = pcct_ss->write_mask;
351
Ashwin Chaugule33350e62015-01-27 16:03:57 -0500352 /* Sync notification from OS to Platform. */
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700353 if (pcc_doorbell_vaddr[id]) {
354 ret = read_register(pcc_doorbell_vaddr[id], &doorbell_val,
355 doorbell->bit_width);
356 if (ret)
357 return ret;
358 ret = write_register(pcc_doorbell_vaddr[id],
359 (doorbell_val & doorbell_preserve) | doorbell_write,
360 doorbell->bit_width);
361 } else {
362 ret = acpi_read(&doorbell_val, doorbell);
363 if (ret)
364 return ret;
365 ret = acpi_write((doorbell_val & doorbell_preserve) | doorbell_write,
366 doorbell);
367 }
368 return ret;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500369}
370
Andrew Bresticker05ae7972015-05-04 10:36:35 -0700371static const struct mbox_chan_ops pcc_chan_ops = {
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500372 .send_data = pcc_send_data,
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500373};
374
375/**
376 * parse_pcc_subspace - Parse the PCC table and verify PCC subspace
377 * entries. There should be one entry per PCC client.
378 * @header: Pointer to the ACPI subtable header under the PCCT.
379 * @end: End of subtable entry.
380 *
381 * Return: 0 for Success, else errno.
382 *
383 * This gets called for each entry in the PCC table.
384 */
385static int parse_pcc_subspace(struct acpi_subtable_header *header,
386 const unsigned long end)
387{
388 struct acpi_pcct_hw_reduced *pcct_ss;
389
390 if (pcc_mbox_ctrl.num_chans <= MAX_PCC_SUBSPACES) {
391 pcct_ss = (struct acpi_pcct_hw_reduced *) header;
392
hotranaca314e2016-08-15 17:14:05 -0700393 if ((pcct_ss->header.type !=
394 ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE)
395 && (pcct_ss->header.type !=
396 ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) {
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500397 pr_err("Incorrect PCC Subspace type detected\n");
398 return -EINVAL;
399 }
400 }
401
402 return 0;
403}
404
405/**
hotranaca314e2016-08-15 17:14:05 -0700406 * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register
407 * There should be one entry per PCC client.
408 * @id: PCC subspace index.
409 * @pcct_ss: Pointer to the ACPI subtable header under the PCCT.
410 *
411 * Return: 0 for Success, else errno.
412 *
413 * This gets called for each entry in the PCC table.
414 */
415static int pcc_parse_subspace_irq(int id,
416 struct acpi_pcct_hw_reduced *pcct_ss)
417{
418 pcc_doorbell_irq[id] = pcc_map_interrupt(pcct_ss->doorbell_interrupt,
419 (u32)pcct_ss->flags);
420 if (pcc_doorbell_irq[id] <= 0) {
421 pr_err("PCC GSI %d not registered\n",
422 pcct_ss->doorbell_interrupt);
423 return -EINVAL;
424 }
425
426 if (pcct_ss->header.type
427 == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
428 struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss;
429
430 pcc_doorbell_ack_vaddr[id] = acpi_os_ioremap(
431 pcct2_ss->doorbell_ack_register.address,
432 pcct2_ss->doorbell_ack_register.bit_width / 8);
433 if (!pcc_doorbell_ack_vaddr[id]) {
434 pr_err("Failed to ioremap PCC ACK register\n");
435 return -ENOMEM;
436 }
437 }
438
439 return 0;
440}
441
442/**
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500443 * acpi_pcc_probe - Parse the ACPI tree for the PCCT.
444 *
445 * Return: 0 for Success, else errno.
446 */
447static int __init acpi_pcc_probe(void)
448{
449 acpi_size pcct_tbl_header_size;
450 struct acpi_table_header *pcct_tbl;
451 struct acpi_subtable_header *pcct_entry;
hotranaca314e2016-08-15 17:14:05 -0700452 struct acpi_table_pcct *acpi_pcct_tbl;
453 int count, i, rc;
454 int sum = 0;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500455 acpi_status status = AE_OK;
456
457 /* Search for PCCT */
458 status = acpi_get_table_with_size(ACPI_SIG_PCCT, 0,
459 &pcct_tbl,
460 &pcct_tbl_header_size);
461
462 if (ACPI_FAILURE(status) || !pcct_tbl) {
463 pr_warn("PCCT header not found.\n");
464 return -ENODEV;
465 }
466
467 count = acpi_table_parse_entries(ACPI_SIG_PCCT,
468 sizeof(struct acpi_table_pcct),
469 ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE,
470 parse_pcc_subspace, MAX_PCC_SUBSPACES);
hotranaca314e2016-08-15 17:14:05 -0700471 sum += (count > 0) ? count : 0;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500472
hotranaca314e2016-08-15 17:14:05 -0700473 count = acpi_table_parse_entries(ACPI_SIG_PCCT,
474 sizeof(struct acpi_table_pcct),
475 ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2,
476 parse_pcc_subspace, MAX_PCC_SUBSPACES);
477 sum += (count > 0) ? count : 0;
478
479 if (sum == 0 || sum >= MAX_PCC_SUBSPACES) {
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500480 pr_err("Error parsing PCC subspaces from PCCT\n");
481 return -EINVAL;
482 }
483
484 pcc_mbox_channels = kzalloc(sizeof(struct mbox_chan) *
hotranaca314e2016-08-15 17:14:05 -0700485 sum, GFP_KERNEL);
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500486 if (!pcc_mbox_channels) {
487 pr_err("Could not allocate space for PCC mbox channels\n");
488 return -ENOMEM;
489 }
490
hotranaca314e2016-08-15 17:14:05 -0700491 pcc_doorbell_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700492 if (!pcc_doorbell_vaddr) {
hotranaca314e2016-08-15 17:14:05 -0700493 rc = -ENOMEM;
494 goto err_free_mbox;
495 }
496
497 pcc_doorbell_ack_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
498 if (!pcc_doorbell_ack_vaddr) {
499 rc = -ENOMEM;
500 goto err_free_db_vaddr;
501 }
502
503 pcc_doorbell_irq = kcalloc(sum, sizeof(int), GFP_KERNEL);
504 if (!pcc_doorbell_irq) {
505 rc = -ENOMEM;
506 goto err_free_db_ack_vaddr;
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700507 }
508
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500509 /* Point to the first PCC subspace entry */
510 pcct_entry = (struct acpi_subtable_header *) (
511 (unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct));
512
hotranaca314e2016-08-15 17:14:05 -0700513 acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl;
514 if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
515 pcc_mbox_ctrl.txdone_irq = true;
516
517 for (i = 0; i < sum; i++) {
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700518 struct acpi_generic_address *db_reg;
519 struct acpi_pcct_hw_reduced *pcct_ss;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500520 pcc_mbox_channels[i].con_priv = pcct_entry;
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700521
hotranaca314e2016-08-15 17:14:05 -0700522 pcct_ss = (struct acpi_pcct_hw_reduced *) pcct_entry;
523
524 if (pcc_mbox_ctrl.txdone_irq) {
525 rc = pcc_parse_subspace_irq(i, pcct_ss);
526 if (rc < 0)
527 goto err;
528 }
529
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700530 /* If doorbell is in system memory cache the virt address */
Prakash, Prashanth8b0f5782016-02-17 13:21:01 -0700531 db_reg = &pcct_ss->doorbell_register;
532 if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
533 pcc_doorbell_vaddr[i] = acpi_os_ioremap(db_reg->address,
534 db_reg->bit_width/8);
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500535 pcct_entry = (struct acpi_subtable_header *)
536 ((unsigned long) pcct_entry + pcct_entry->length);
537 }
538
hotranaca314e2016-08-15 17:14:05 -0700539 pcc_mbox_ctrl.num_chans = sum;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500540
541 pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans);
542
543 return 0;
hotranaca314e2016-08-15 17:14:05 -0700544
545err:
546 kfree(pcc_doorbell_irq);
547err_free_db_ack_vaddr:
548 kfree(pcc_doorbell_ack_vaddr);
549err_free_db_vaddr:
550 kfree(pcc_doorbell_vaddr);
551err_free_mbox:
552 kfree(pcc_mbox_channels);
553 return rc;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500554}
555
556/**
557 * pcc_mbox_probe - Called when we find a match for the
558 * PCCT platform device. This is purely used to represent
559 * the PCCT as a virtual device for registering with the
560 * generic Mailbox framework.
561 *
562 * @pdev: Pointer to platform device returned when a match
563 * is found.
564 *
565 * Return: 0 for Success, else errno.
566 */
567static int pcc_mbox_probe(struct platform_device *pdev)
568{
569 int ret = 0;
570
571 pcc_mbox_ctrl.chans = pcc_mbox_channels;
572 pcc_mbox_ctrl.ops = &pcc_chan_ops;
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500573 pcc_mbox_ctrl.dev = &pdev->dev;
574
575 pr_info("Registering PCC driver as Mailbox controller\n");
576 ret = mbox_controller_register(&pcc_mbox_ctrl);
577
578 if (ret) {
579 pr_err("Err registering PCC as Mailbox controller: %d\n", ret);
580 ret = -ENODEV;
581 }
582
583 return ret;
584}
585
586struct platform_driver pcc_mbox_driver = {
587 .probe = pcc_mbox_probe,
588 .driver = {
589 .name = "PCCT",
590 .owner = THIS_MODULE,
591 },
592};
593
594static int __init pcc_init(void)
595{
596 int ret;
597 struct platform_device *pcc_pdev;
598
599 if (acpi_disabled)
600 return -ENODEV;
601
602 /* Check if PCC support is available. */
603 ret = acpi_pcc_probe();
604
605 if (ret) {
Rafael J. Wysockiefd756d2015-02-05 00:40:08 +0100606 pr_debug("ACPI PCC probe failed.\n");
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500607 return -ENODEV;
608 }
609
610 pcc_pdev = platform_create_bundle(&pcc_mbox_driver,
611 pcc_mbox_probe, NULL, 0, NULL, 0);
612
Wei Yongjun356d5d22015-01-14 09:10:56 +0800613 if (IS_ERR(pcc_pdev)) {
Rafael J. Wysockiefd756d2015-02-05 00:40:08 +0100614 pr_debug("Err creating PCC platform bundle\n");
Wei Yongjun356d5d22015-01-14 09:10:56 +0800615 return PTR_ERR(pcc_pdev);
Ashwin Chaugule86c22f82014-11-12 19:59:38 -0500616 }
617
618 return 0;
619}
Ashwin Chauguled3c68f22015-08-05 09:40:24 -0400620
621/*
622 * Make PCC init postcore so that users of this mailbox
623 * such as the ACPI Processor driver have it available
624 * at their init.
625 */
626postcore_initcall(pcc_init);