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1/*
2 * System Control and Power Interface (SCPI) Message Protocol driver
3 *
4 * SCPI Message Protocol is used between the System Control Processor(SCP)
5 * and the Application Processors(AP). The Message Handling Unit(MHU)
6 * provides a mechanism for inter-processor communication between SCP's
7 * Cortex M3 and AP.
8 *
9 * SCP offers control and management of the core/cluster power states,
10 * various power domain DVFS including the core/cluster, certain system
11 * clocks configuration, thermal sensors and many others.
12 *
13 * Copyright (C) 2015 ARM Ltd.
14 *
15 * This program is free software; you can redistribute it and/or modify it
16 * under the terms and conditions of the GNU General Public License,
17 * version 2, as published by the Free Software Foundation.
18 *
19 * This program is distributed in the hope it will be useful, but WITHOUT
20 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
22 * more details.
23 *
24 * You should have received a copy of the GNU General Public License along
25 * with this program. If not, see <http://www.gnu.org/licenses/>.
26 */
27
28#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30#include <linux/bitmap.h>
31#include <linux/device.h>
32#include <linux/err.h>
33#include <linux/export.h>
34#include <linux/io.h>
35#include <linux/kernel.h>
36#include <linux/list.h>
37#include <linux/mailbox_client.h>
38#include <linux/module.h>
39#include <linux/of_address.h>
40#include <linux/of_platform.h>
41#include <linux/printk.h>
42#include <linux/scpi_protocol.h>
43#include <linux/slab.h>
44#include <linux/sort.h>
45#include <linux/spinlock.h>
46
47#define CMD_ID_SHIFT 0
48#define CMD_ID_MASK 0x7f
49#define CMD_TOKEN_ID_SHIFT 8
50#define CMD_TOKEN_ID_MASK 0xff
51#define CMD_DATA_SIZE_SHIFT 16
52#define CMD_DATA_SIZE_MASK 0x1ff
53#define PACK_SCPI_CMD(cmd_id, tx_sz) \
54 ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) | \
55 (((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
56#define ADD_SCPI_TOKEN(cmd, token) \
57 ((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
58
59#define CMD_SIZE(cmd) (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
60#define CMD_UNIQ_MASK (CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
61#define CMD_XTRACT_UNIQ(cmd) ((cmd) & CMD_UNIQ_MASK)
62
63#define SCPI_SLOT 0
64
65#define MAX_DVFS_DOMAINS 8
66#define MAX_DVFS_OPPS 8
67#define DVFS_LATENCY(hdr) (le32_to_cpu(hdr) >> 16)
68#define DVFS_OPP_COUNT(hdr) ((le32_to_cpu(hdr) >> 8) & 0xff)
69
70#define PROTOCOL_REV_MINOR_BITS 16
71#define PROTOCOL_REV_MINOR_MASK ((1U << PROTOCOL_REV_MINOR_BITS) - 1)
72#define PROTOCOL_REV_MAJOR(x) ((x) >> PROTOCOL_REV_MINOR_BITS)
73#define PROTOCOL_REV_MINOR(x) ((x) & PROTOCOL_REV_MINOR_MASK)
74
75#define FW_REV_MAJOR_BITS 24
76#define FW_REV_MINOR_BITS 16
77#define FW_REV_PATCH_MASK ((1U << FW_REV_MINOR_BITS) - 1)
78#define FW_REV_MINOR_MASK ((1U << FW_REV_MAJOR_BITS) - 1)
79#define FW_REV_MAJOR(x) ((x) >> FW_REV_MAJOR_BITS)
80#define FW_REV_MINOR(x) (((x) & FW_REV_MINOR_MASK) >> FW_REV_MINOR_BITS)
81#define FW_REV_PATCH(x) ((x) & FW_REV_PATCH_MASK)
82
83#define MAX_RX_TIMEOUT (msecs_to_jiffies(30))
84
85enum scpi_error_codes {
86 SCPI_SUCCESS = 0, /* Success */
87 SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
88 SCPI_ERR_ALIGN = 2, /* Invalid alignment */
89 SCPI_ERR_SIZE = 3, /* Invalid size */
90 SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
91 SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
92 SCPI_ERR_RANGE = 6, /* Value out of range */
93 SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
94 SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
95 SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
96 SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
97 SCPI_ERR_DEVICE = 11, /* Device error */
98 SCPI_ERR_BUSY = 12, /* Device busy */
99 SCPI_ERR_MAX
100};
101
102enum scpi_std_cmd {
103 SCPI_CMD_INVALID = 0x00,
104 SCPI_CMD_SCPI_READY = 0x01,
105 SCPI_CMD_SCPI_CAPABILITIES = 0x02,
106 SCPI_CMD_SET_CSS_PWR_STATE = 0x03,
107 SCPI_CMD_GET_CSS_PWR_STATE = 0x04,
108 SCPI_CMD_SET_SYS_PWR_STATE = 0x05,
109 SCPI_CMD_SET_CPU_TIMER = 0x06,
110 SCPI_CMD_CANCEL_CPU_TIMER = 0x07,
111 SCPI_CMD_DVFS_CAPABILITIES = 0x08,
112 SCPI_CMD_GET_DVFS_INFO = 0x09,
113 SCPI_CMD_SET_DVFS = 0x0a,
114 SCPI_CMD_GET_DVFS = 0x0b,
115 SCPI_CMD_GET_DVFS_STAT = 0x0c,
116 SCPI_CMD_CLOCK_CAPABILITIES = 0x0d,
117 SCPI_CMD_GET_CLOCK_INFO = 0x0e,
118 SCPI_CMD_SET_CLOCK_VALUE = 0x0f,
119 SCPI_CMD_GET_CLOCK_VALUE = 0x10,
120 SCPI_CMD_PSU_CAPABILITIES = 0x11,
121 SCPI_CMD_GET_PSU_INFO = 0x12,
122 SCPI_CMD_SET_PSU = 0x13,
123 SCPI_CMD_GET_PSU = 0x14,
124 SCPI_CMD_SENSOR_CAPABILITIES = 0x15,
125 SCPI_CMD_SENSOR_INFO = 0x16,
126 SCPI_CMD_SENSOR_VALUE = 0x17,
127 SCPI_CMD_SENSOR_CFG_PERIODIC = 0x18,
128 SCPI_CMD_SENSOR_CFG_BOUNDS = 0x19,
129 SCPI_CMD_SENSOR_ASYNC_VALUE = 0x1a,
130 SCPI_CMD_SET_DEVICE_PWR_STATE = 0x1b,
131 SCPI_CMD_GET_DEVICE_PWR_STATE = 0x1c,
132 SCPI_CMD_COUNT
133};
134
135struct scpi_xfer {
136 u32 slot; /* has to be first element */
137 u32 cmd;
138 u32 status;
139 const void *tx_buf;
140 void *rx_buf;
141 unsigned int tx_len;
142 unsigned int rx_len;
143 struct list_head node;
144 struct completion done;
145};
146
147struct scpi_chan {
148 struct mbox_client cl;
149 struct mbox_chan *chan;
150 void __iomem *tx_payload;
151 void __iomem *rx_payload;
152 struct list_head rx_pending;
153 struct list_head xfers_list;
154 struct scpi_xfer *xfers;
155 spinlock_t rx_lock; /* locking for the rx pending list */
156 struct mutex xfers_lock;
157 u8 token;
158};
159
160struct scpi_drvinfo {
161 u32 protocol_version;
162 u32 firmware_version;
163 int num_chans;
164 atomic_t next_chan;
165 struct scpi_ops *scpi_ops;
166 struct scpi_chan *channels;
167 struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
168};
169
170/*
171 * The SCP firmware only executes in little-endian mode, so any buffers
172 * shared through SCPI should have their contents converted to little-endian
173 */
174struct scpi_shared_mem {
175 __le32 command;
176 __le32 status;
177 u8 payload[0];
178} __packed;
179
180struct scp_capabilities {
181 __le32 protocol_version;
182 __le32 event_version;
183 __le32 platform_version;
184 __le32 commands[4];
185} __packed;
186
187struct clk_get_info {
188 __le16 id;
189 __le16 flags;
190 __le32 min_rate;
191 __le32 max_rate;
192 u8 name[20];
193} __packed;
194
195struct clk_get_value {
196 __le32 rate;
197} __packed;
198
199struct clk_set_value {
200 __le16 id;
201 __le16 reserved;
202 __le32 rate;
203} __packed;
204
205struct dvfs_info {
206 __le32 header;
207 struct {
208 __le32 freq;
209 __le32 m_volt;
210 } opps[MAX_DVFS_OPPS];
211} __packed;
212
213struct dvfs_get {
214 u8 index;
215} __packed;
216
217struct dvfs_set {
218 u8 domain;
219 u8 index;
220} __packed;
221
222struct sensor_capabilities {
223 __le16 sensors;
224} __packed;
225
226struct _scpi_sensor_info {
227 __le16 sensor_id;
228 u8 class;
229 u8 trigger_type;
230 char name[20];
231};
232
233struct sensor_value {
234 __le32 lo_val;
235 __le32 hi_val;
236} __packed;
237
238static struct scpi_drvinfo *scpi_info;
239
240static int scpi_linux_errmap[SCPI_ERR_MAX] = {
241 /* better than switch case as long as return value is continuous */
242 0, /* SCPI_SUCCESS */
243 -EINVAL, /* SCPI_ERR_PARAM */
244 -ENOEXEC, /* SCPI_ERR_ALIGN */
245 -EMSGSIZE, /* SCPI_ERR_SIZE */
246 -EINVAL, /* SCPI_ERR_HANDLER */
247 -EACCES, /* SCPI_ERR_ACCESS */
248 -ERANGE, /* SCPI_ERR_RANGE */
249 -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
250 -ENOMEM, /* SCPI_ERR_NOMEM */
251 -EINVAL, /* SCPI_ERR_PWRSTATE */
252 -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
253 -EIO, /* SCPI_ERR_DEVICE */
254 -EBUSY, /* SCPI_ERR_BUSY */
255};
256
257static inline int scpi_to_linux_errno(int errno)
258{
259 if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
260 return scpi_linux_errmap[errno];
261 return -EIO;
262}
263
264static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
265{
266 unsigned long flags;
267 struct scpi_xfer *t, *match = NULL;
268
269 spin_lock_irqsave(&ch->rx_lock, flags);
270 if (list_empty(&ch->rx_pending)) {
271 spin_unlock_irqrestore(&ch->rx_lock, flags);
272 return;
273 }
274
275 list_for_each_entry(t, &ch->rx_pending, node)
276 if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
277 list_del(&t->node);
278 match = t;
279 break;
280 }
281 /* check if wait_for_completion is in progress or timed-out */
282 if (match && !completion_done(&match->done)) {
283 struct scpi_shared_mem *mem = ch->rx_payload;
284 unsigned int len = min(match->rx_len, CMD_SIZE(cmd));
285
286 match->status = le32_to_cpu(mem->status);
287 memcpy_fromio(match->rx_buf, mem->payload, len);
288 if (match->rx_len > len)
289 memset(match->rx_buf + len, 0, match->rx_len - len);
290 complete(&match->done);
291 }
292 spin_unlock_irqrestore(&ch->rx_lock, flags);
293}
294
295static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
296{
297 struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
298 struct scpi_shared_mem *mem = ch->rx_payload;
299 u32 cmd = le32_to_cpu(mem->command);
300
301 scpi_process_cmd(ch, cmd);
302}
303
304static void scpi_tx_prepare(struct mbox_client *c, void *msg)
305{
306 unsigned long flags;
307 struct scpi_xfer *t = msg;
308 struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
309 struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
310
311 if (t->tx_buf)
312 memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
313 if (t->rx_buf) {
314 if (!(++ch->token))
315 ++ch->token;
316 ADD_SCPI_TOKEN(t->cmd, ch->token);
317 spin_lock_irqsave(&ch->rx_lock, flags);
318 list_add_tail(&t->node, &ch->rx_pending);
319 spin_unlock_irqrestore(&ch->rx_lock, flags);
320 }
321 mem->command = cpu_to_le32(t->cmd);
322}
323
324static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
325{
326 struct scpi_xfer *t;
327
328 mutex_lock(&ch->xfers_lock);
329 if (list_empty(&ch->xfers_list)) {
330 mutex_unlock(&ch->xfers_lock);
331 return NULL;
332 }
333 t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
334 list_del(&t->node);
335 mutex_unlock(&ch->xfers_lock);
336 return t;
337}
338
339static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
340{
341 mutex_lock(&ch->xfers_lock);
342 list_add_tail(&t->node, &ch->xfers_list);
343 mutex_unlock(&ch->xfers_lock);
344}
345
346static int scpi_send_message(u8 cmd, void *tx_buf, unsigned int tx_len,
347 void *rx_buf, unsigned int rx_len)
348{
349 int ret;
350 u8 chan;
351 struct scpi_xfer *msg;
352 struct scpi_chan *scpi_chan;
353
354 chan = atomic_inc_return(&scpi_info->next_chan) % scpi_info->num_chans;
355 scpi_chan = scpi_info->channels + chan;
356
357 msg = get_scpi_xfer(scpi_chan);
358 if (!msg)
359 return -ENOMEM;
360
361 msg->slot = BIT(SCPI_SLOT);
362 msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
363 msg->tx_buf = tx_buf;
364 msg->tx_len = tx_len;
365 msg->rx_buf = rx_buf;
366 msg->rx_len = rx_len;
367 init_completion(&msg->done);
368
369 ret = mbox_send_message(scpi_chan->chan, msg);
370 if (ret < 0 || !rx_buf)
371 goto out;
372
373 if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
374 ret = -ETIMEDOUT;
375 else
376 /* first status word */
377 ret = msg->status;
378out:
379 if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
380 scpi_process_cmd(scpi_chan, msg->cmd);
381
382 put_scpi_xfer(msg, scpi_chan);
383 /* SCPI error codes > 0, translate them to Linux scale*/
384 return ret > 0 ? scpi_to_linux_errno(ret) : ret;
385}
386
387static u32 scpi_get_version(void)
388{
389 return scpi_info->protocol_version;
390}
391
392static int
393scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
394{
395 int ret;
396 struct clk_get_info clk;
397 __le16 le_clk_id = cpu_to_le16(clk_id);
398
399 ret = scpi_send_message(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
400 sizeof(le_clk_id), &clk, sizeof(clk));
401 if (!ret) {
402 *min = le32_to_cpu(clk.min_rate);
403 *max = le32_to_cpu(clk.max_rate);
404 }
405 return ret;
406}
407
408static unsigned long scpi_clk_get_val(u16 clk_id)
409{
410 int ret;
411 struct clk_get_value clk;
412 __le16 le_clk_id = cpu_to_le16(clk_id);
413
414 ret = scpi_send_message(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
415 sizeof(le_clk_id), &clk, sizeof(clk));
416 return ret ? ret : le32_to_cpu(clk.rate);
417}
418
419static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
420{
421 int stat;
422 struct clk_set_value clk = {
423 .id = cpu_to_le16(clk_id),
424 .rate = cpu_to_le32(rate)
425 };
426
427 return scpi_send_message(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
428 &stat, sizeof(stat));
429}
430
431static int scpi_dvfs_get_idx(u8 domain)
432{
433 int ret;
434 struct dvfs_get dvfs;
435
436 ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
437 &dvfs, sizeof(dvfs));
438 return ret ? ret : dvfs.index;
439}
440
441static int scpi_dvfs_set_idx(u8 domain, u8 index)
442{
443 int stat;
444 struct dvfs_set dvfs = {domain, index};
445
446 return scpi_send_message(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
447 &stat, sizeof(stat));
448}
449
450static int opp_cmp_func(const void *opp1, const void *opp2)
451{
452 const struct scpi_opp *t1 = opp1, *t2 = opp2;
453
454 return t1->freq - t2->freq;
455}
456
457static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
458{
459 struct scpi_dvfs_info *info;
460 struct scpi_opp *opp;
461 struct dvfs_info buf;
462 int ret, i;
463
464 if (domain >= MAX_DVFS_DOMAINS)
465 return ERR_PTR(-EINVAL);
466
467 if (scpi_info->dvfs[domain]) /* data already populated */
468 return scpi_info->dvfs[domain];
469
470 ret = scpi_send_message(SCPI_CMD_GET_DVFS_INFO, &domain, sizeof(domain),
471 &buf, sizeof(buf));
472
473 if (ret)
474 return ERR_PTR(ret);
475
476 info = kmalloc(sizeof(*info), GFP_KERNEL);
477 if (!info)
478 return ERR_PTR(-ENOMEM);
479
480 info->count = DVFS_OPP_COUNT(buf.header);
481 info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
482
483 info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
484 if (!info->opps) {
485 kfree(info);
486 return ERR_PTR(-ENOMEM);
487 }
488
489 for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
490 opp->freq = le32_to_cpu(buf.opps[i].freq);
491 opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
492 }
493
494 sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
495
496 scpi_info->dvfs[domain] = info;
497 return info;
498}
499
500static int scpi_sensor_get_capability(u16 *sensors)
501{
502 struct sensor_capabilities cap_buf;
503 int ret;
504
505 ret = scpi_send_message(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
506 sizeof(cap_buf));
507 if (!ret)
508 *sensors = le16_to_cpu(cap_buf.sensors);
509
510 return ret;
511}
512
513static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
514{
515 __le16 id = cpu_to_le16(sensor_id);
516 struct _scpi_sensor_info _info;
517 int ret;
518
519 ret = scpi_send_message(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
520 &_info, sizeof(_info));
521 if (!ret) {
522 memcpy(info, &_info, sizeof(*info));
523 info->sensor_id = le16_to_cpu(_info.sensor_id);
524 }
525
526 return ret;
527}
528
529int scpi_sensor_get_value(u16 sensor, u64 *val)
530{
531 __le16 id = cpu_to_le16(sensor);
532 struct sensor_value buf;
533 int ret;
534
535 ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &id, sizeof(id),
536 &buf, sizeof(buf));
537 if (!ret)
538 *val = (u64)le32_to_cpu(buf.hi_val) << 32 |
539 le32_to_cpu(buf.lo_val);
540
541 return ret;
542}
543
544static struct scpi_ops scpi_ops = {
545 .get_version = scpi_get_version,
546 .clk_get_range = scpi_clk_get_range,
547 .clk_get_val = scpi_clk_get_val,
548 .clk_set_val = scpi_clk_set_val,
549 .dvfs_get_idx = scpi_dvfs_get_idx,
550 .dvfs_set_idx = scpi_dvfs_set_idx,
551 .dvfs_get_info = scpi_dvfs_get_info,
552 .sensor_get_capability = scpi_sensor_get_capability,
553 .sensor_get_info = scpi_sensor_get_info,
554 .sensor_get_value = scpi_sensor_get_value,
555};
556
557struct scpi_ops *get_scpi_ops(void)
558{
559 return scpi_info ? scpi_info->scpi_ops : NULL;
560}
561EXPORT_SYMBOL_GPL(get_scpi_ops);
562
563static int scpi_init_versions(struct scpi_drvinfo *info)
564{
565 int ret;
566 struct scp_capabilities caps;
567
568 ret = scpi_send_message(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
569 &caps, sizeof(caps));
570 if (!ret) {
571 info->protocol_version = le32_to_cpu(caps.protocol_version);
572 info->firmware_version = le32_to_cpu(caps.platform_version);
573 }
574 return ret;
575}
576
577static ssize_t protocol_version_show(struct device *dev,
578 struct device_attribute *attr, char *buf)
579{
580 struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
581
582 return sprintf(buf, "%d.%d\n",
583 PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
584 PROTOCOL_REV_MINOR(scpi_info->protocol_version));
585}
586static DEVICE_ATTR_RO(protocol_version);
587
588static ssize_t firmware_version_show(struct device *dev,
589 struct device_attribute *attr, char *buf)
590{
591 struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
592
593 return sprintf(buf, "%d.%d.%d\n",
594 FW_REV_MAJOR(scpi_info->firmware_version),
595 FW_REV_MINOR(scpi_info->firmware_version),
596 FW_REV_PATCH(scpi_info->firmware_version));
597}
598static DEVICE_ATTR_RO(firmware_version);
599
600static struct attribute *versions_attrs[] = {
601 &dev_attr_firmware_version.attr,
602 &dev_attr_protocol_version.attr,
603 NULL,
604};
605ATTRIBUTE_GROUPS(versions);
606
607static void
608scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
609{
610 int i;
611
612 for (i = 0; i < count && pchan->chan; i++, pchan++) {
613 mbox_free_channel(pchan->chan);
614 devm_kfree(dev, pchan->xfers);
615 devm_iounmap(dev, pchan->rx_payload);
616 }
617}
618
619static int scpi_remove(struct platform_device *pdev)
620{
621 int i;
622 struct device *dev = &pdev->dev;
623 struct scpi_drvinfo *info = platform_get_drvdata(pdev);
624
625 scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
626
627 of_platform_depopulate(dev);
628 sysfs_remove_groups(&dev->kobj, versions_groups);
629 scpi_free_channels(dev, info->channels, info->num_chans);
630 platform_set_drvdata(pdev, NULL);
631
632 for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
633 kfree(info->dvfs[i]->opps);
634 kfree(info->dvfs[i]);
635 }
636 devm_kfree(dev, info->channels);
637 devm_kfree(dev, info);
638
639 return 0;
640}
641
642#define MAX_SCPI_XFERS 10
643static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
644{
645 int i;
646 struct scpi_xfer *xfers;
647
648 xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
649 if (!xfers)
650 return -ENOMEM;
651
652 ch->xfers = xfers;
653 for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++)
654 list_add_tail(&xfers->node, &ch->xfers_list);
655 return 0;
656}
657
658static int scpi_probe(struct platform_device *pdev)
659{
660 int count, idx, ret;
661 struct resource res;
662 struct scpi_chan *scpi_chan;
663 struct device *dev = &pdev->dev;
664 struct device_node *np = dev->of_node;
665
666 scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
667 if (!scpi_info)
668 return -ENOMEM;
669
670 count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
671 if (count < 0) {
672 dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
673 return -ENODEV;
674 }
675
676 scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
677 if (!scpi_chan)
678 return -ENOMEM;
679
680 for (idx = 0; idx < count; idx++) {
681 resource_size_t size;
682 struct scpi_chan *pchan = scpi_chan + idx;
683 struct mbox_client *cl = &pchan->cl;
684 struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
685
686 if (of_address_to_resource(shmem, 0, &res)) {
687 dev_err(dev, "failed to get SCPI payload mem resource\n");
688 ret = -EINVAL;
689 goto err;
690 }
691
692 size = resource_size(&res);
693 pchan->rx_payload = devm_ioremap(dev, res.start, size);
694 if (!pchan->rx_payload) {
695 dev_err(dev, "failed to ioremap SCPI payload\n");
696 ret = -EADDRNOTAVAIL;
697 goto err;
698 }
699 pchan->tx_payload = pchan->rx_payload + (size >> 1);
700
701 cl->dev = dev;
702 cl->rx_callback = scpi_handle_remote_msg;
703 cl->tx_prepare = scpi_tx_prepare;
704 cl->tx_block = true;
705 cl->tx_tout = 20;
706 cl->knows_txdone = false; /* controller can't ack */
707
708 INIT_LIST_HEAD(&pchan->rx_pending);
709 INIT_LIST_HEAD(&pchan->xfers_list);
710 spin_lock_init(&pchan->rx_lock);
711 mutex_init(&pchan->xfers_lock);
712
713 ret = scpi_alloc_xfer_list(dev, pchan);
714 if (!ret) {
715 pchan->chan = mbox_request_channel(cl, idx);
716 if (!IS_ERR(pchan->chan))
717 continue;
718 ret = PTR_ERR(pchan->chan);
719 if (ret != -EPROBE_DEFER)
720 dev_err(dev, "failed to get channel%d err %d\n",
721 idx, ret);
722 }
723err:
724 scpi_free_channels(dev, scpi_chan, idx);
725 scpi_info = NULL;
726 return ret;
727 }
728
729 scpi_info->channels = scpi_chan;
730 scpi_info->num_chans = count;
731 platform_set_drvdata(pdev, scpi_info);
732
733 ret = scpi_init_versions(scpi_info);
734 if (ret) {
735 dev_err(dev, "incorrect or no SCP firmware found\n");
736 scpi_remove(pdev);
737 return ret;
738 }
739
740 _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
741 PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
742 PROTOCOL_REV_MINOR(scpi_info->protocol_version),
743 FW_REV_MAJOR(scpi_info->firmware_version),
744 FW_REV_MINOR(scpi_info->firmware_version),
745 FW_REV_PATCH(scpi_info->firmware_version));
746 scpi_info->scpi_ops = &scpi_ops;
747
748 ret = sysfs_create_groups(&dev->kobj, versions_groups);
749 if (ret)
750 dev_err(dev, "unable to create sysfs version group\n");
751
752 return of_platform_populate(dev->of_node, NULL, NULL, dev);
753}
754
755static const struct of_device_id scpi_of_match[] = {
756 {.compatible = "arm,scpi"},
757 {},
758};
759
760MODULE_DEVICE_TABLE(of, scpi_of_match);
761
762static struct platform_driver scpi_driver = {
763 .driver = {
764 .name = "scpi_protocol",
765 .of_match_table = scpi_of_match,
766 },
767 .probe = scpi_probe,
768 .remove = scpi_remove,
769};
770module_platform_driver(scpi_driver);
771
772MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
773MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
774MODULE_LICENSE("GPL v2");