xref: /openbmc/linux/drivers/firmware/arm_scpi.c (revision ebd09753)
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/bitfield.h>
32 #include <linux/device.h>
33 #include <linux/err.h>
34 #include <linux/export.h>
35 #include <linux/io.h>
36 #include <linux/kernel.h>
37 #include <linux/list.h>
38 #include <linux/mailbox_client.h>
39 #include <linux/module.h>
40 #include <linux/of_address.h>
41 #include <linux/of_platform.h>
42 #include <linux/printk.h>
43 #include <linux/pm_opp.h>
44 #include <linux/scpi_protocol.h>
45 #include <linux/slab.h>
46 #include <linux/sort.h>
47 #include <linux/spinlock.h>
48 
49 #define CMD_ID_MASK		GENMASK(6, 0)
50 #define CMD_TOKEN_ID_MASK	GENMASK(15, 8)
51 #define CMD_DATA_SIZE_MASK	GENMASK(24, 16)
52 #define CMD_LEGACY_DATA_SIZE_MASK	GENMASK(28, 20)
53 #define PACK_SCPI_CMD(cmd_id, tx_sz)		\
54 	(FIELD_PREP(CMD_ID_MASK, cmd_id) |	\
55 	FIELD_PREP(CMD_DATA_SIZE_MASK, tx_sz))
56 #define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)	\
57 	(FIELD_PREP(CMD_ID_MASK, cmd_id) |	\
58 	FIELD_PREP(CMD_LEGACY_DATA_SIZE_MASK, tx_sz))
59 
60 #define CMD_SIZE(cmd)	FIELD_GET(CMD_DATA_SIZE_MASK, cmd)
61 #define CMD_UNIQ_MASK	(CMD_TOKEN_ID_MASK | CMD_ID_MASK)
62 #define CMD_XTRACT_UNIQ(cmd)	((cmd) & CMD_UNIQ_MASK)
63 
64 #define SCPI_SLOT		0
65 
66 #define MAX_DVFS_DOMAINS	8
67 #define MAX_DVFS_OPPS		16
68 
69 #define PROTO_REV_MAJOR_MASK	GENMASK(31, 16)
70 #define PROTO_REV_MINOR_MASK	GENMASK(15, 0)
71 
72 #define FW_REV_MAJOR_MASK	GENMASK(31, 24)
73 #define FW_REV_MINOR_MASK	GENMASK(23, 16)
74 #define FW_REV_PATCH_MASK	GENMASK(15, 0)
75 
76 #define MAX_RX_TIMEOUT		(msecs_to_jiffies(30))
77 
78 enum scpi_error_codes {
79 	SCPI_SUCCESS = 0, /* Success */
80 	SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
81 	SCPI_ERR_ALIGN = 2, /* Invalid alignment */
82 	SCPI_ERR_SIZE = 3, /* Invalid size */
83 	SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
84 	SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
85 	SCPI_ERR_RANGE = 6, /* Value out of range */
86 	SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
87 	SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
88 	SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
89 	SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
90 	SCPI_ERR_DEVICE = 11, /* Device error */
91 	SCPI_ERR_BUSY = 12, /* Device busy */
92 	SCPI_ERR_MAX
93 };
94 
95 /* SCPI Standard commands */
96 enum scpi_std_cmd {
97 	SCPI_CMD_INVALID		= 0x00,
98 	SCPI_CMD_SCPI_READY		= 0x01,
99 	SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
100 	SCPI_CMD_SET_CSS_PWR_STATE	= 0x03,
101 	SCPI_CMD_GET_CSS_PWR_STATE	= 0x04,
102 	SCPI_CMD_SET_SYS_PWR_STATE	= 0x05,
103 	SCPI_CMD_SET_CPU_TIMER		= 0x06,
104 	SCPI_CMD_CANCEL_CPU_TIMER	= 0x07,
105 	SCPI_CMD_DVFS_CAPABILITIES	= 0x08,
106 	SCPI_CMD_GET_DVFS_INFO		= 0x09,
107 	SCPI_CMD_SET_DVFS		= 0x0a,
108 	SCPI_CMD_GET_DVFS		= 0x0b,
109 	SCPI_CMD_GET_DVFS_STAT		= 0x0c,
110 	SCPI_CMD_CLOCK_CAPABILITIES	= 0x0d,
111 	SCPI_CMD_GET_CLOCK_INFO		= 0x0e,
112 	SCPI_CMD_SET_CLOCK_VALUE	= 0x0f,
113 	SCPI_CMD_GET_CLOCK_VALUE	= 0x10,
114 	SCPI_CMD_PSU_CAPABILITIES	= 0x11,
115 	SCPI_CMD_GET_PSU_INFO		= 0x12,
116 	SCPI_CMD_SET_PSU		= 0x13,
117 	SCPI_CMD_GET_PSU		= 0x14,
118 	SCPI_CMD_SENSOR_CAPABILITIES	= 0x15,
119 	SCPI_CMD_SENSOR_INFO		= 0x16,
120 	SCPI_CMD_SENSOR_VALUE		= 0x17,
121 	SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x18,
122 	SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x19,
123 	SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1a,
124 	SCPI_CMD_SET_DEVICE_PWR_STATE	= 0x1b,
125 	SCPI_CMD_GET_DEVICE_PWR_STATE	= 0x1c,
126 	SCPI_CMD_COUNT
127 };
128 
129 /* SCPI Legacy Commands */
130 enum legacy_scpi_std_cmd {
131 	LEGACY_SCPI_CMD_INVALID			= 0x00,
132 	LEGACY_SCPI_CMD_SCPI_READY		= 0x01,
133 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
134 	LEGACY_SCPI_CMD_EVENT			= 0x03,
135 	LEGACY_SCPI_CMD_SET_CSS_PWR_STATE	= 0x04,
136 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE	= 0x05,
137 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT	= 0x06,
138 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT	= 0x07,
139 	LEGACY_SCPI_CMD_SYS_PWR_STATE		= 0x08,
140 	LEGACY_SCPI_CMD_L2_READY		= 0x09,
141 	LEGACY_SCPI_CMD_SET_AP_TIMER		= 0x0a,
142 	LEGACY_SCPI_CMD_CANCEL_AP_TIME		= 0x0b,
143 	LEGACY_SCPI_CMD_DVFS_CAPABILITIES	= 0x0c,
144 	LEGACY_SCPI_CMD_GET_DVFS_INFO		= 0x0d,
145 	LEGACY_SCPI_CMD_SET_DVFS		= 0x0e,
146 	LEGACY_SCPI_CMD_GET_DVFS		= 0x0f,
147 	LEGACY_SCPI_CMD_GET_DVFS_STAT		= 0x10,
148 	LEGACY_SCPI_CMD_SET_RTC			= 0x11,
149 	LEGACY_SCPI_CMD_GET_RTC			= 0x12,
150 	LEGACY_SCPI_CMD_CLOCK_CAPABILITIES	= 0x13,
151 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX		= 0x14,
152 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE		= 0x15,
153 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE		= 0x16,
154 	LEGACY_SCPI_CMD_PSU_CAPABILITIES	= 0x17,
155 	LEGACY_SCPI_CMD_SET_PSU			= 0x18,
156 	LEGACY_SCPI_CMD_GET_PSU			= 0x19,
157 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES	= 0x1a,
158 	LEGACY_SCPI_CMD_SENSOR_INFO		= 0x1b,
159 	LEGACY_SCPI_CMD_SENSOR_VALUE		= 0x1c,
160 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x1d,
161 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x1e,
162 	LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1f,
163 	LEGACY_SCPI_CMD_COUNT
164 };
165 
166 /* List all commands that are required to go through the high priority link */
167 static int legacy_hpriority_cmds[] = {
168 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
169 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
170 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
171 	LEGACY_SCPI_CMD_SET_DVFS,
172 	LEGACY_SCPI_CMD_GET_DVFS,
173 	LEGACY_SCPI_CMD_SET_RTC,
174 	LEGACY_SCPI_CMD_GET_RTC,
175 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
176 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
177 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
178 	LEGACY_SCPI_CMD_SET_PSU,
179 	LEGACY_SCPI_CMD_GET_PSU,
180 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
181 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
182 };
183 
184 /* List all commands used by this driver, used as indexes */
185 enum scpi_drv_cmds {
186 	CMD_SCPI_CAPABILITIES = 0,
187 	CMD_GET_CLOCK_INFO,
188 	CMD_GET_CLOCK_VALUE,
189 	CMD_SET_CLOCK_VALUE,
190 	CMD_GET_DVFS,
191 	CMD_SET_DVFS,
192 	CMD_GET_DVFS_INFO,
193 	CMD_SENSOR_CAPABILITIES,
194 	CMD_SENSOR_INFO,
195 	CMD_SENSOR_VALUE,
196 	CMD_SET_DEVICE_PWR_STATE,
197 	CMD_GET_DEVICE_PWR_STATE,
198 	CMD_MAX_COUNT,
199 };
200 
201 static int scpi_std_commands[CMD_MAX_COUNT] = {
202 	SCPI_CMD_SCPI_CAPABILITIES,
203 	SCPI_CMD_GET_CLOCK_INFO,
204 	SCPI_CMD_GET_CLOCK_VALUE,
205 	SCPI_CMD_SET_CLOCK_VALUE,
206 	SCPI_CMD_GET_DVFS,
207 	SCPI_CMD_SET_DVFS,
208 	SCPI_CMD_GET_DVFS_INFO,
209 	SCPI_CMD_SENSOR_CAPABILITIES,
210 	SCPI_CMD_SENSOR_INFO,
211 	SCPI_CMD_SENSOR_VALUE,
212 	SCPI_CMD_SET_DEVICE_PWR_STATE,
213 	SCPI_CMD_GET_DEVICE_PWR_STATE,
214 };
215 
216 static int scpi_legacy_commands[CMD_MAX_COUNT] = {
217 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
218 	-1, /* GET_CLOCK_INFO */
219 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
220 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
221 	LEGACY_SCPI_CMD_GET_DVFS,
222 	LEGACY_SCPI_CMD_SET_DVFS,
223 	LEGACY_SCPI_CMD_GET_DVFS_INFO,
224 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
225 	LEGACY_SCPI_CMD_SENSOR_INFO,
226 	LEGACY_SCPI_CMD_SENSOR_VALUE,
227 	-1, /* SET_DEVICE_PWR_STATE */
228 	-1, /* GET_DEVICE_PWR_STATE */
229 };
230 
231 struct scpi_xfer {
232 	u32 slot; /* has to be first element */
233 	u32 cmd;
234 	u32 status;
235 	const void *tx_buf;
236 	void *rx_buf;
237 	unsigned int tx_len;
238 	unsigned int rx_len;
239 	struct list_head node;
240 	struct completion done;
241 };
242 
243 struct scpi_chan {
244 	struct mbox_client cl;
245 	struct mbox_chan *chan;
246 	void __iomem *tx_payload;
247 	void __iomem *rx_payload;
248 	struct list_head rx_pending;
249 	struct list_head xfers_list;
250 	struct scpi_xfer *xfers;
251 	spinlock_t rx_lock; /* locking for the rx pending list */
252 	struct mutex xfers_lock;
253 	u8 token;
254 };
255 
256 struct scpi_drvinfo {
257 	u32 protocol_version;
258 	u32 firmware_version;
259 	bool is_legacy;
260 	int num_chans;
261 	int *commands;
262 	DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
263 	atomic_t next_chan;
264 	struct scpi_ops *scpi_ops;
265 	struct scpi_chan *channels;
266 	struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
267 };
268 
269 /*
270  * The SCP firmware only executes in little-endian mode, so any buffers
271  * shared through SCPI should have their contents converted to little-endian
272  */
273 struct scpi_shared_mem {
274 	__le32 command;
275 	__le32 status;
276 	u8 payload[0];
277 } __packed;
278 
279 struct legacy_scpi_shared_mem {
280 	__le32 status;
281 	u8 payload[0];
282 } __packed;
283 
284 struct scp_capabilities {
285 	__le32 protocol_version;
286 	__le32 event_version;
287 	__le32 platform_version;
288 	__le32 commands[4];
289 } __packed;
290 
291 struct clk_get_info {
292 	__le16 id;
293 	__le16 flags;
294 	__le32 min_rate;
295 	__le32 max_rate;
296 	u8 name[20];
297 } __packed;
298 
299 struct clk_set_value {
300 	__le16 id;
301 	__le16 reserved;
302 	__le32 rate;
303 } __packed;
304 
305 struct legacy_clk_set_value {
306 	__le32 rate;
307 	__le16 id;
308 	__le16 reserved;
309 } __packed;
310 
311 struct dvfs_info {
312 	u8 domain;
313 	u8 opp_count;
314 	__le16 latency;
315 	struct {
316 		__le32 freq;
317 		__le32 m_volt;
318 	} opps[MAX_DVFS_OPPS];
319 } __packed;
320 
321 struct dvfs_set {
322 	u8 domain;
323 	u8 index;
324 } __packed;
325 
326 struct _scpi_sensor_info {
327 	__le16 sensor_id;
328 	u8 class;
329 	u8 trigger_type;
330 	char name[20];
331 };
332 
333 struct dev_pstate_set {
334 	__le16 dev_id;
335 	u8 pstate;
336 } __packed;
337 
338 static struct scpi_drvinfo *scpi_info;
339 
340 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
341 	/* better than switch case as long as return value is continuous */
342 	0, /* SCPI_SUCCESS */
343 	-EINVAL, /* SCPI_ERR_PARAM */
344 	-ENOEXEC, /* SCPI_ERR_ALIGN */
345 	-EMSGSIZE, /* SCPI_ERR_SIZE */
346 	-EINVAL, /* SCPI_ERR_HANDLER */
347 	-EACCES, /* SCPI_ERR_ACCESS */
348 	-ERANGE, /* SCPI_ERR_RANGE */
349 	-ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
350 	-ENOMEM, /* SCPI_ERR_NOMEM */
351 	-EINVAL, /* SCPI_ERR_PWRSTATE */
352 	-EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
353 	-EIO, /* SCPI_ERR_DEVICE */
354 	-EBUSY, /* SCPI_ERR_BUSY */
355 };
356 
357 static inline int scpi_to_linux_errno(int errno)
358 {
359 	if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
360 		return scpi_linux_errmap[errno];
361 	return -EIO;
362 }
363 
364 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
365 {
366 	unsigned long flags;
367 	struct scpi_xfer *t, *match = NULL;
368 
369 	spin_lock_irqsave(&ch->rx_lock, flags);
370 	if (list_empty(&ch->rx_pending)) {
371 		spin_unlock_irqrestore(&ch->rx_lock, flags);
372 		return;
373 	}
374 
375 	/* Command type is not replied by the SCP Firmware in legacy Mode
376 	 * We should consider that command is the head of pending RX commands
377 	 * if the list is not empty. In TX only mode, the list would be empty.
378 	 */
379 	if (scpi_info->is_legacy) {
380 		match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
381 					 node);
382 		list_del(&match->node);
383 	} else {
384 		list_for_each_entry(t, &ch->rx_pending, node)
385 			if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
386 				list_del(&t->node);
387 				match = t;
388 				break;
389 			}
390 	}
391 	/* check if wait_for_completion is in progress or timed-out */
392 	if (match && !completion_done(&match->done)) {
393 		unsigned int len;
394 
395 		if (scpi_info->is_legacy) {
396 			struct legacy_scpi_shared_mem __iomem *mem =
397 							ch->rx_payload;
398 
399 			/* RX Length is not replied by the legacy Firmware */
400 			len = match->rx_len;
401 
402 			match->status = ioread32(&mem->status);
403 			memcpy_fromio(match->rx_buf, mem->payload, len);
404 		} else {
405 			struct scpi_shared_mem __iomem *mem = ch->rx_payload;
406 
407 			len = min_t(unsigned int, match->rx_len, CMD_SIZE(cmd));
408 
409 			match->status = ioread32(&mem->status);
410 			memcpy_fromio(match->rx_buf, mem->payload, len);
411 		}
412 
413 		if (match->rx_len > len)
414 			memset(match->rx_buf + len, 0, match->rx_len - len);
415 		complete(&match->done);
416 	}
417 	spin_unlock_irqrestore(&ch->rx_lock, flags);
418 }
419 
420 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
421 {
422 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
423 	struct scpi_shared_mem __iomem *mem = ch->rx_payload;
424 	u32 cmd = 0;
425 
426 	if (!scpi_info->is_legacy)
427 		cmd = ioread32(&mem->command);
428 
429 	scpi_process_cmd(ch, cmd);
430 }
431 
432 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
433 {
434 	unsigned long flags;
435 	struct scpi_xfer *t = msg;
436 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
437 	struct scpi_shared_mem __iomem *mem = ch->tx_payload;
438 
439 	if (t->tx_buf) {
440 		if (scpi_info->is_legacy)
441 			memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
442 		else
443 			memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
444 	}
445 
446 	if (t->rx_buf) {
447 		if (!(++ch->token))
448 			++ch->token;
449 		t->cmd |= FIELD_PREP(CMD_TOKEN_ID_MASK, ch->token);
450 		spin_lock_irqsave(&ch->rx_lock, flags);
451 		list_add_tail(&t->node, &ch->rx_pending);
452 		spin_unlock_irqrestore(&ch->rx_lock, flags);
453 	}
454 
455 	if (!scpi_info->is_legacy)
456 		iowrite32(t->cmd, &mem->command);
457 }
458 
459 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
460 {
461 	struct scpi_xfer *t;
462 
463 	mutex_lock(&ch->xfers_lock);
464 	if (list_empty(&ch->xfers_list)) {
465 		mutex_unlock(&ch->xfers_lock);
466 		return NULL;
467 	}
468 	t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
469 	list_del(&t->node);
470 	mutex_unlock(&ch->xfers_lock);
471 	return t;
472 }
473 
474 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
475 {
476 	mutex_lock(&ch->xfers_lock);
477 	list_add_tail(&t->node, &ch->xfers_list);
478 	mutex_unlock(&ch->xfers_lock);
479 }
480 
481 static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
482 			     void *rx_buf, unsigned int rx_len)
483 {
484 	int ret;
485 	u8 chan;
486 	u8 cmd;
487 	struct scpi_xfer *msg;
488 	struct scpi_chan *scpi_chan;
489 
490 	if (scpi_info->commands[idx] < 0)
491 		return -EOPNOTSUPP;
492 
493 	cmd = scpi_info->commands[idx];
494 
495 	if (scpi_info->is_legacy)
496 		chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
497 	else
498 		chan = atomic_inc_return(&scpi_info->next_chan) %
499 			scpi_info->num_chans;
500 	scpi_chan = scpi_info->channels + chan;
501 
502 	msg = get_scpi_xfer(scpi_chan);
503 	if (!msg)
504 		return -ENOMEM;
505 
506 	if (scpi_info->is_legacy) {
507 		msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
508 		msg->slot = msg->cmd;
509 	} else {
510 		msg->slot = BIT(SCPI_SLOT);
511 		msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
512 	}
513 	msg->tx_buf = tx_buf;
514 	msg->tx_len = tx_len;
515 	msg->rx_buf = rx_buf;
516 	msg->rx_len = rx_len;
517 	reinit_completion(&msg->done);
518 
519 	ret = mbox_send_message(scpi_chan->chan, msg);
520 	if (ret < 0 || !rx_buf)
521 		goto out;
522 
523 	if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
524 		ret = -ETIMEDOUT;
525 	else
526 		/* first status word */
527 		ret = msg->status;
528 out:
529 	if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
530 		scpi_process_cmd(scpi_chan, msg->cmd);
531 
532 	put_scpi_xfer(msg, scpi_chan);
533 	/* SCPI error codes > 0, translate them to Linux scale*/
534 	return ret > 0 ? scpi_to_linux_errno(ret) : ret;
535 }
536 
537 static u32 scpi_get_version(void)
538 {
539 	return scpi_info->protocol_version;
540 }
541 
542 static int
543 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
544 {
545 	int ret;
546 	struct clk_get_info clk;
547 	__le16 le_clk_id = cpu_to_le16(clk_id);
548 
549 	ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
550 				sizeof(le_clk_id), &clk, sizeof(clk));
551 	if (!ret) {
552 		*min = le32_to_cpu(clk.min_rate);
553 		*max = le32_to_cpu(clk.max_rate);
554 	}
555 	return ret;
556 }
557 
558 static unsigned long scpi_clk_get_val(u16 clk_id)
559 {
560 	int ret;
561 	__le32 rate;
562 	__le16 le_clk_id = cpu_to_le16(clk_id);
563 
564 	ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
565 				sizeof(le_clk_id), &rate, sizeof(rate));
566 
567 	return ret ? ret : le32_to_cpu(rate);
568 }
569 
570 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
571 {
572 	int stat;
573 	struct clk_set_value clk = {
574 		.id = cpu_to_le16(clk_id),
575 		.rate = cpu_to_le32(rate)
576 	};
577 
578 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
579 				 &stat, sizeof(stat));
580 }
581 
582 static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
583 {
584 	int stat;
585 	struct legacy_clk_set_value clk = {
586 		.id = cpu_to_le16(clk_id),
587 		.rate = cpu_to_le32(rate)
588 	};
589 
590 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
591 				 &stat, sizeof(stat));
592 }
593 
594 static int scpi_dvfs_get_idx(u8 domain)
595 {
596 	int ret;
597 	u8 dvfs_idx;
598 
599 	ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
600 				&dvfs_idx, sizeof(dvfs_idx));
601 
602 	return ret ? ret : dvfs_idx;
603 }
604 
605 static int scpi_dvfs_set_idx(u8 domain, u8 index)
606 {
607 	int stat;
608 	struct dvfs_set dvfs = {domain, index};
609 
610 	return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
611 				 &stat, sizeof(stat));
612 }
613 
614 static int opp_cmp_func(const void *opp1, const void *opp2)
615 {
616 	const struct scpi_opp *t1 = opp1, *t2 = opp2;
617 
618 	return t1->freq - t2->freq;
619 }
620 
621 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
622 {
623 	struct scpi_dvfs_info *info;
624 	struct scpi_opp *opp;
625 	struct dvfs_info buf;
626 	int ret, i;
627 
628 	if (domain >= MAX_DVFS_DOMAINS)
629 		return ERR_PTR(-EINVAL);
630 
631 	if (scpi_info->dvfs[domain])	/* data already populated */
632 		return scpi_info->dvfs[domain];
633 
634 	ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
635 				&buf, sizeof(buf));
636 	if (ret)
637 		return ERR_PTR(ret);
638 
639 	info = kmalloc(sizeof(*info), GFP_KERNEL);
640 	if (!info)
641 		return ERR_PTR(-ENOMEM);
642 
643 	info->count = buf.opp_count;
644 	info->latency = le16_to_cpu(buf.latency) * 1000; /* uS to nS */
645 
646 	info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
647 	if (!info->opps) {
648 		kfree(info);
649 		return ERR_PTR(-ENOMEM);
650 	}
651 
652 	for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
653 		opp->freq = le32_to_cpu(buf.opps[i].freq);
654 		opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
655 	}
656 
657 	sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
658 
659 	scpi_info->dvfs[domain] = info;
660 	return info;
661 }
662 
663 static int scpi_dev_domain_id(struct device *dev)
664 {
665 	struct of_phandle_args clkspec;
666 
667 	if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
668 				       0, &clkspec))
669 		return -EINVAL;
670 
671 	return clkspec.args[0];
672 }
673 
674 static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
675 {
676 	int domain = scpi_dev_domain_id(dev);
677 
678 	if (domain < 0)
679 		return ERR_PTR(domain);
680 
681 	return scpi_dvfs_get_info(domain);
682 }
683 
684 static int scpi_dvfs_get_transition_latency(struct device *dev)
685 {
686 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
687 
688 	if (IS_ERR(info))
689 		return PTR_ERR(info);
690 
691 	return info->latency;
692 }
693 
694 static int scpi_dvfs_add_opps_to_device(struct device *dev)
695 {
696 	int idx, ret;
697 	struct scpi_opp *opp;
698 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
699 
700 	if (IS_ERR(info))
701 		return PTR_ERR(info);
702 
703 	if (!info->opps)
704 		return -EIO;
705 
706 	for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
707 		ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
708 		if (ret) {
709 			dev_warn(dev, "failed to add opp %uHz %umV\n",
710 				 opp->freq, opp->m_volt);
711 			while (idx-- > 0)
712 				dev_pm_opp_remove(dev, (--opp)->freq);
713 			return ret;
714 		}
715 	}
716 	return 0;
717 }
718 
719 static int scpi_sensor_get_capability(u16 *sensors)
720 {
721 	__le16 cap;
722 	int ret;
723 
724 	ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap,
725 				sizeof(cap));
726 	if (!ret)
727 		*sensors = le16_to_cpu(cap);
728 
729 	return ret;
730 }
731 
732 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
733 {
734 	__le16 id = cpu_to_le16(sensor_id);
735 	struct _scpi_sensor_info _info;
736 	int ret;
737 
738 	ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
739 				&_info, sizeof(_info));
740 	if (!ret) {
741 		memcpy(info, &_info, sizeof(*info));
742 		info->sensor_id = le16_to_cpu(_info.sensor_id);
743 	}
744 
745 	return ret;
746 }
747 
748 static int scpi_sensor_get_value(u16 sensor, u64 *val)
749 {
750 	__le16 id = cpu_to_le16(sensor);
751 	__le64 value;
752 	int ret;
753 
754 	ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
755 				&value, sizeof(value));
756 	if (ret)
757 		return ret;
758 
759 	if (scpi_info->is_legacy)
760 		/* only 32-bits supported, upper 32 bits can be junk */
761 		*val = le32_to_cpup((__le32 *)&value);
762 	else
763 		*val = le64_to_cpu(value);
764 
765 	return 0;
766 }
767 
768 static int scpi_device_get_power_state(u16 dev_id)
769 {
770 	int ret;
771 	u8 pstate;
772 	__le16 id = cpu_to_le16(dev_id);
773 
774 	ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
775 				sizeof(id), &pstate, sizeof(pstate));
776 	return ret ? ret : pstate;
777 }
778 
779 static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
780 {
781 	int stat;
782 	struct dev_pstate_set dev_set = {
783 		.dev_id = cpu_to_le16(dev_id),
784 		.pstate = pstate,
785 	};
786 
787 	return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
788 				 sizeof(dev_set), &stat, sizeof(stat));
789 }
790 
791 static struct scpi_ops scpi_ops = {
792 	.get_version = scpi_get_version,
793 	.clk_get_range = scpi_clk_get_range,
794 	.clk_get_val = scpi_clk_get_val,
795 	.clk_set_val = scpi_clk_set_val,
796 	.dvfs_get_idx = scpi_dvfs_get_idx,
797 	.dvfs_set_idx = scpi_dvfs_set_idx,
798 	.dvfs_get_info = scpi_dvfs_get_info,
799 	.device_domain_id = scpi_dev_domain_id,
800 	.get_transition_latency = scpi_dvfs_get_transition_latency,
801 	.add_opps_to_device = scpi_dvfs_add_opps_to_device,
802 	.sensor_get_capability = scpi_sensor_get_capability,
803 	.sensor_get_info = scpi_sensor_get_info,
804 	.sensor_get_value = scpi_sensor_get_value,
805 	.device_get_power_state = scpi_device_get_power_state,
806 	.device_set_power_state = scpi_device_set_power_state,
807 };
808 
809 struct scpi_ops *get_scpi_ops(void)
810 {
811 	return scpi_info ? scpi_info->scpi_ops : NULL;
812 }
813 EXPORT_SYMBOL_GPL(get_scpi_ops);
814 
815 static int scpi_init_versions(struct scpi_drvinfo *info)
816 {
817 	int ret;
818 	struct scp_capabilities caps;
819 
820 	ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
821 				&caps, sizeof(caps));
822 	if (!ret) {
823 		info->protocol_version = le32_to_cpu(caps.protocol_version);
824 		info->firmware_version = le32_to_cpu(caps.platform_version);
825 	}
826 	/* Ignore error if not implemented */
827 	if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
828 		return 0;
829 
830 	return ret;
831 }
832 
833 static ssize_t protocol_version_show(struct device *dev,
834 				     struct device_attribute *attr, char *buf)
835 {
836 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
837 
838 	return sprintf(buf, "%lu.%lu\n",
839 		FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
840 		FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version));
841 }
842 static DEVICE_ATTR_RO(protocol_version);
843 
844 static ssize_t firmware_version_show(struct device *dev,
845 				     struct device_attribute *attr, char *buf)
846 {
847 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
848 
849 	return sprintf(buf, "%lu.%lu.%lu\n",
850 		FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
851 		FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
852 		FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
853 }
854 static DEVICE_ATTR_RO(firmware_version);
855 
856 static struct attribute *versions_attrs[] = {
857 	&dev_attr_firmware_version.attr,
858 	&dev_attr_protocol_version.attr,
859 	NULL,
860 };
861 ATTRIBUTE_GROUPS(versions);
862 
863 static void scpi_free_channels(void *data)
864 {
865 	struct scpi_drvinfo *info = data;
866 	int i;
867 
868 	for (i = 0; i < info->num_chans; i++)
869 		mbox_free_channel(info->channels[i].chan);
870 }
871 
872 static int scpi_remove(struct platform_device *pdev)
873 {
874 	int i;
875 	struct scpi_drvinfo *info = platform_get_drvdata(pdev);
876 
877 	scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
878 
879 	for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
880 		kfree(info->dvfs[i]->opps);
881 		kfree(info->dvfs[i]);
882 	}
883 
884 	return 0;
885 }
886 
887 #define MAX_SCPI_XFERS		10
888 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
889 {
890 	int i;
891 	struct scpi_xfer *xfers;
892 
893 	xfers = devm_kcalloc(dev, MAX_SCPI_XFERS, sizeof(*xfers), GFP_KERNEL);
894 	if (!xfers)
895 		return -ENOMEM;
896 
897 	ch->xfers = xfers;
898 	for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
899 		init_completion(&xfers->done);
900 		list_add_tail(&xfers->node, &ch->xfers_list);
901 	}
902 
903 	return 0;
904 }
905 
906 static const struct of_device_id legacy_scpi_of_match[] = {
907 	{.compatible = "arm,scpi-pre-1.0"},
908 	{},
909 };
910 
911 static int scpi_probe(struct platform_device *pdev)
912 {
913 	int count, idx, ret;
914 	struct resource res;
915 	struct device *dev = &pdev->dev;
916 	struct device_node *np = dev->of_node;
917 
918 	scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
919 	if (!scpi_info)
920 		return -ENOMEM;
921 
922 	if (of_match_device(legacy_scpi_of_match, &pdev->dev))
923 		scpi_info->is_legacy = true;
924 
925 	count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
926 	if (count < 0) {
927 		dev_err(dev, "no mboxes property in '%pOF'\n", np);
928 		return -ENODEV;
929 	}
930 
931 	scpi_info->channels = devm_kcalloc(dev, count, sizeof(struct scpi_chan),
932 					   GFP_KERNEL);
933 	if (!scpi_info->channels)
934 		return -ENOMEM;
935 
936 	ret = devm_add_action(dev, scpi_free_channels, scpi_info);
937 	if (ret)
938 		return ret;
939 
940 	for (; scpi_info->num_chans < count; scpi_info->num_chans++) {
941 		resource_size_t size;
942 		int idx = scpi_info->num_chans;
943 		struct scpi_chan *pchan = scpi_info->channels + idx;
944 		struct mbox_client *cl = &pchan->cl;
945 		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
946 
947 		ret = of_address_to_resource(shmem, 0, &res);
948 		of_node_put(shmem);
949 		if (ret) {
950 			dev_err(dev, "failed to get SCPI payload mem resource\n");
951 			return ret;
952 		}
953 
954 		size = resource_size(&res);
955 		pchan->rx_payload = devm_ioremap(dev, res.start, size);
956 		if (!pchan->rx_payload) {
957 			dev_err(dev, "failed to ioremap SCPI payload\n");
958 			return -EADDRNOTAVAIL;
959 		}
960 		pchan->tx_payload = pchan->rx_payload + (size >> 1);
961 
962 		cl->dev = dev;
963 		cl->rx_callback = scpi_handle_remote_msg;
964 		cl->tx_prepare = scpi_tx_prepare;
965 		cl->tx_block = true;
966 		cl->tx_tout = 20;
967 		cl->knows_txdone = false; /* controller can't ack */
968 
969 		INIT_LIST_HEAD(&pchan->rx_pending);
970 		INIT_LIST_HEAD(&pchan->xfers_list);
971 		spin_lock_init(&pchan->rx_lock);
972 		mutex_init(&pchan->xfers_lock);
973 
974 		ret = scpi_alloc_xfer_list(dev, pchan);
975 		if (!ret) {
976 			pchan->chan = mbox_request_channel(cl, idx);
977 			if (!IS_ERR(pchan->chan))
978 				continue;
979 			ret = PTR_ERR(pchan->chan);
980 			if (ret != -EPROBE_DEFER)
981 				dev_err(dev, "failed to get channel%d err %d\n",
982 					idx, ret);
983 		}
984 		return ret;
985 	}
986 
987 	scpi_info->commands = scpi_std_commands;
988 
989 	platform_set_drvdata(pdev, scpi_info);
990 
991 	if (scpi_info->is_legacy) {
992 		/* Replace with legacy variants */
993 		scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
994 		scpi_info->commands = scpi_legacy_commands;
995 
996 		/* Fill priority bitmap */
997 		for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
998 			set_bit(legacy_hpriority_cmds[idx],
999 				scpi_info->cmd_priority);
1000 	}
1001 
1002 	ret = scpi_init_versions(scpi_info);
1003 	if (ret) {
1004 		dev_err(dev, "incorrect or no SCP firmware found\n");
1005 		return ret;
1006 	}
1007 
1008 	if (scpi_info->is_legacy && !scpi_info->protocol_version &&
1009 	    !scpi_info->firmware_version)
1010 		dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
1011 	else
1012 		dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1013 			 FIELD_GET(PROTO_REV_MAJOR_MASK,
1014 				   scpi_info->protocol_version),
1015 			 FIELD_GET(PROTO_REV_MINOR_MASK,
1016 				   scpi_info->protocol_version),
1017 			 FIELD_GET(FW_REV_MAJOR_MASK,
1018 				   scpi_info->firmware_version),
1019 			 FIELD_GET(FW_REV_MINOR_MASK,
1020 				   scpi_info->firmware_version),
1021 			 FIELD_GET(FW_REV_PATCH_MASK,
1022 				   scpi_info->firmware_version));
1023 	scpi_info->scpi_ops = &scpi_ops;
1024 
1025 	ret = devm_device_add_groups(dev, versions_groups);
1026 	if (ret)
1027 		dev_err(dev, "unable to create sysfs version group\n");
1028 
1029 	return devm_of_platform_populate(dev);
1030 }
1031 
1032 static const struct of_device_id scpi_of_match[] = {
1033 	{.compatible = "arm,scpi"},
1034 	{.compatible = "arm,scpi-pre-1.0"},
1035 	{},
1036 };
1037 
1038 MODULE_DEVICE_TABLE(of, scpi_of_match);
1039 
1040 static struct platform_driver scpi_driver = {
1041 	.driver = {
1042 		.name = "scpi_protocol",
1043 		.of_match_table = scpi_of_match,
1044 	},
1045 	.probe = scpi_probe,
1046 	.remove = scpi_remove,
1047 };
1048 module_platform_driver(scpi_driver);
1049 
1050 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1051 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1052 MODULE_LICENSE("GPL v2");
1053