xref: /openbmc/linux/drivers/firmware/arm_scpi.c (revision fb960bd2)
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_SHIFT		0
50 #define CMD_ID_MASK		0x7f
51 #define CMD_TOKEN_ID_SHIFT	8
52 #define CMD_TOKEN_ID_MASK	0xff
53 #define CMD_DATA_SIZE_SHIFT	16
54 #define CMD_DATA_SIZE_MASK	0x1ff
55 #define CMD_LEGACY_DATA_SIZE_SHIFT	20
56 #define CMD_LEGACY_DATA_SIZE_MASK	0x1ff
57 #define PACK_SCPI_CMD(cmd_id, tx_sz)			\
58 	((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |	\
59 	(((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
60 #define ADD_SCPI_TOKEN(cmd, token)			\
61 	((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
62 #define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)				\
63 	((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |			       \
64 	(((tx_sz) & CMD_LEGACY_DATA_SIZE_MASK) << CMD_LEGACY_DATA_SIZE_SHIFT))
65 
66 #define CMD_SIZE(cmd)	(((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
67 #define CMD_LEGACY_SIZE(cmd)	(((cmd) >> CMD_LEGACY_DATA_SIZE_SHIFT) & \
68 					CMD_LEGACY_DATA_SIZE_MASK)
69 #define CMD_UNIQ_MASK	(CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
70 #define CMD_XTRACT_UNIQ(cmd)	((cmd) & CMD_UNIQ_MASK)
71 
72 #define SCPI_SLOT		0
73 
74 #define MAX_DVFS_DOMAINS	8
75 #define MAX_DVFS_OPPS		16
76 
77 #define PROTO_REV_MAJOR_MASK	GENMASK(31, 16)
78 #define PROTO_REV_MINOR_MASK	GENMASK(15, 0)
79 
80 #define FW_REV_MAJOR_MASK	GENMASK(31, 24)
81 #define FW_REV_MINOR_MASK	GENMASK(23, 16)
82 #define FW_REV_PATCH_MASK	GENMASK(15, 0)
83 
84 #define MAX_RX_TIMEOUT		(msecs_to_jiffies(30))
85 
86 enum scpi_error_codes {
87 	SCPI_SUCCESS = 0, /* Success */
88 	SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
89 	SCPI_ERR_ALIGN = 2, /* Invalid alignment */
90 	SCPI_ERR_SIZE = 3, /* Invalid size */
91 	SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
92 	SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
93 	SCPI_ERR_RANGE = 6, /* Value out of range */
94 	SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
95 	SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
96 	SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
97 	SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
98 	SCPI_ERR_DEVICE = 11, /* Device error */
99 	SCPI_ERR_BUSY = 12, /* Device busy */
100 	SCPI_ERR_MAX
101 };
102 
103 /* SCPI Standard commands */
104 enum scpi_std_cmd {
105 	SCPI_CMD_INVALID		= 0x00,
106 	SCPI_CMD_SCPI_READY		= 0x01,
107 	SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
108 	SCPI_CMD_SET_CSS_PWR_STATE	= 0x03,
109 	SCPI_CMD_GET_CSS_PWR_STATE	= 0x04,
110 	SCPI_CMD_SET_SYS_PWR_STATE	= 0x05,
111 	SCPI_CMD_SET_CPU_TIMER		= 0x06,
112 	SCPI_CMD_CANCEL_CPU_TIMER	= 0x07,
113 	SCPI_CMD_DVFS_CAPABILITIES	= 0x08,
114 	SCPI_CMD_GET_DVFS_INFO		= 0x09,
115 	SCPI_CMD_SET_DVFS		= 0x0a,
116 	SCPI_CMD_GET_DVFS		= 0x0b,
117 	SCPI_CMD_GET_DVFS_STAT		= 0x0c,
118 	SCPI_CMD_CLOCK_CAPABILITIES	= 0x0d,
119 	SCPI_CMD_GET_CLOCK_INFO		= 0x0e,
120 	SCPI_CMD_SET_CLOCK_VALUE	= 0x0f,
121 	SCPI_CMD_GET_CLOCK_VALUE	= 0x10,
122 	SCPI_CMD_PSU_CAPABILITIES	= 0x11,
123 	SCPI_CMD_GET_PSU_INFO		= 0x12,
124 	SCPI_CMD_SET_PSU		= 0x13,
125 	SCPI_CMD_GET_PSU		= 0x14,
126 	SCPI_CMD_SENSOR_CAPABILITIES	= 0x15,
127 	SCPI_CMD_SENSOR_INFO		= 0x16,
128 	SCPI_CMD_SENSOR_VALUE		= 0x17,
129 	SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x18,
130 	SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x19,
131 	SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1a,
132 	SCPI_CMD_SET_DEVICE_PWR_STATE	= 0x1b,
133 	SCPI_CMD_GET_DEVICE_PWR_STATE	= 0x1c,
134 	SCPI_CMD_COUNT
135 };
136 
137 /* SCPI Legacy Commands */
138 enum legacy_scpi_std_cmd {
139 	LEGACY_SCPI_CMD_INVALID			= 0x00,
140 	LEGACY_SCPI_CMD_SCPI_READY		= 0x01,
141 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
142 	LEGACY_SCPI_CMD_EVENT			= 0x03,
143 	LEGACY_SCPI_CMD_SET_CSS_PWR_STATE	= 0x04,
144 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE	= 0x05,
145 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT	= 0x06,
146 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT	= 0x07,
147 	LEGACY_SCPI_CMD_SYS_PWR_STATE		= 0x08,
148 	LEGACY_SCPI_CMD_L2_READY		= 0x09,
149 	LEGACY_SCPI_CMD_SET_AP_TIMER		= 0x0a,
150 	LEGACY_SCPI_CMD_CANCEL_AP_TIME		= 0x0b,
151 	LEGACY_SCPI_CMD_DVFS_CAPABILITIES	= 0x0c,
152 	LEGACY_SCPI_CMD_GET_DVFS_INFO		= 0x0d,
153 	LEGACY_SCPI_CMD_SET_DVFS		= 0x0e,
154 	LEGACY_SCPI_CMD_GET_DVFS		= 0x0f,
155 	LEGACY_SCPI_CMD_GET_DVFS_STAT		= 0x10,
156 	LEGACY_SCPI_CMD_SET_RTC			= 0x11,
157 	LEGACY_SCPI_CMD_GET_RTC			= 0x12,
158 	LEGACY_SCPI_CMD_CLOCK_CAPABILITIES	= 0x13,
159 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX		= 0x14,
160 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE		= 0x15,
161 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE		= 0x16,
162 	LEGACY_SCPI_CMD_PSU_CAPABILITIES	= 0x17,
163 	LEGACY_SCPI_CMD_SET_PSU			= 0x18,
164 	LEGACY_SCPI_CMD_GET_PSU			= 0x19,
165 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES	= 0x1a,
166 	LEGACY_SCPI_CMD_SENSOR_INFO		= 0x1b,
167 	LEGACY_SCPI_CMD_SENSOR_VALUE		= 0x1c,
168 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x1d,
169 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x1e,
170 	LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1f,
171 	LEGACY_SCPI_CMD_COUNT
172 };
173 
174 /* List all commands that are required to go through the high priority link */
175 static int legacy_hpriority_cmds[] = {
176 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
177 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
178 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
179 	LEGACY_SCPI_CMD_SET_DVFS,
180 	LEGACY_SCPI_CMD_GET_DVFS,
181 	LEGACY_SCPI_CMD_SET_RTC,
182 	LEGACY_SCPI_CMD_GET_RTC,
183 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
184 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
185 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
186 	LEGACY_SCPI_CMD_SET_PSU,
187 	LEGACY_SCPI_CMD_GET_PSU,
188 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
189 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
190 };
191 
192 /* List all commands used by this driver, used as indexes */
193 enum scpi_drv_cmds {
194 	CMD_SCPI_CAPABILITIES = 0,
195 	CMD_GET_CLOCK_INFO,
196 	CMD_GET_CLOCK_VALUE,
197 	CMD_SET_CLOCK_VALUE,
198 	CMD_GET_DVFS,
199 	CMD_SET_DVFS,
200 	CMD_GET_DVFS_INFO,
201 	CMD_SENSOR_CAPABILITIES,
202 	CMD_SENSOR_INFO,
203 	CMD_SENSOR_VALUE,
204 	CMD_SET_DEVICE_PWR_STATE,
205 	CMD_GET_DEVICE_PWR_STATE,
206 	CMD_MAX_COUNT,
207 };
208 
209 static int scpi_std_commands[CMD_MAX_COUNT] = {
210 	SCPI_CMD_SCPI_CAPABILITIES,
211 	SCPI_CMD_GET_CLOCK_INFO,
212 	SCPI_CMD_GET_CLOCK_VALUE,
213 	SCPI_CMD_SET_CLOCK_VALUE,
214 	SCPI_CMD_GET_DVFS,
215 	SCPI_CMD_SET_DVFS,
216 	SCPI_CMD_GET_DVFS_INFO,
217 	SCPI_CMD_SENSOR_CAPABILITIES,
218 	SCPI_CMD_SENSOR_INFO,
219 	SCPI_CMD_SENSOR_VALUE,
220 	SCPI_CMD_SET_DEVICE_PWR_STATE,
221 	SCPI_CMD_GET_DEVICE_PWR_STATE,
222 };
223 
224 static int scpi_legacy_commands[CMD_MAX_COUNT] = {
225 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
226 	-1, /* GET_CLOCK_INFO */
227 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
228 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
229 	LEGACY_SCPI_CMD_GET_DVFS,
230 	LEGACY_SCPI_CMD_SET_DVFS,
231 	LEGACY_SCPI_CMD_GET_DVFS_INFO,
232 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
233 	LEGACY_SCPI_CMD_SENSOR_INFO,
234 	LEGACY_SCPI_CMD_SENSOR_VALUE,
235 	-1, /* SET_DEVICE_PWR_STATE */
236 	-1, /* GET_DEVICE_PWR_STATE */
237 };
238 
239 struct scpi_xfer {
240 	u32 slot; /* has to be first element */
241 	u32 cmd;
242 	u32 status;
243 	const void *tx_buf;
244 	void *rx_buf;
245 	unsigned int tx_len;
246 	unsigned int rx_len;
247 	struct list_head node;
248 	struct completion done;
249 };
250 
251 struct scpi_chan {
252 	struct mbox_client cl;
253 	struct mbox_chan *chan;
254 	void __iomem *tx_payload;
255 	void __iomem *rx_payload;
256 	struct list_head rx_pending;
257 	struct list_head xfers_list;
258 	struct scpi_xfer *xfers;
259 	spinlock_t rx_lock; /* locking for the rx pending list */
260 	struct mutex xfers_lock;
261 	u8 token;
262 };
263 
264 struct scpi_drvinfo {
265 	u32 protocol_version;
266 	u32 firmware_version;
267 	bool is_legacy;
268 	int num_chans;
269 	int *commands;
270 	DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
271 	atomic_t next_chan;
272 	struct scpi_ops *scpi_ops;
273 	struct scpi_chan *channels;
274 	struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
275 };
276 
277 /*
278  * The SCP firmware only executes in little-endian mode, so any buffers
279  * shared through SCPI should have their contents converted to little-endian
280  */
281 struct scpi_shared_mem {
282 	__le32 command;
283 	__le32 status;
284 	u8 payload[0];
285 } __packed;
286 
287 struct legacy_scpi_shared_mem {
288 	__le32 status;
289 	u8 payload[0];
290 } __packed;
291 
292 struct scp_capabilities {
293 	__le32 protocol_version;
294 	__le32 event_version;
295 	__le32 platform_version;
296 	__le32 commands[4];
297 } __packed;
298 
299 struct clk_get_info {
300 	__le16 id;
301 	__le16 flags;
302 	__le32 min_rate;
303 	__le32 max_rate;
304 	u8 name[20];
305 } __packed;
306 
307 struct clk_set_value {
308 	__le16 id;
309 	__le16 reserved;
310 	__le32 rate;
311 } __packed;
312 
313 struct legacy_clk_set_value {
314 	__le32 rate;
315 	__le16 id;
316 	__le16 reserved;
317 } __packed;
318 
319 struct dvfs_info {
320 	u8 domain;
321 	u8 opp_count;
322 	__le16 latency;
323 	struct {
324 		__le32 freq;
325 		__le32 m_volt;
326 	} opps[MAX_DVFS_OPPS];
327 } __packed;
328 
329 struct dvfs_set {
330 	u8 domain;
331 	u8 index;
332 } __packed;
333 
334 struct sensor_capabilities {
335 	__le16 sensors;
336 } __packed;
337 
338 struct _scpi_sensor_info {
339 	__le16 sensor_id;
340 	u8 class;
341 	u8 trigger_type;
342 	char name[20];
343 };
344 
345 struct dev_pstate_set {
346 	__le16 dev_id;
347 	u8 pstate;
348 } __packed;
349 
350 static struct scpi_drvinfo *scpi_info;
351 
352 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
353 	/* better than switch case as long as return value is continuous */
354 	0, /* SCPI_SUCCESS */
355 	-EINVAL, /* SCPI_ERR_PARAM */
356 	-ENOEXEC, /* SCPI_ERR_ALIGN */
357 	-EMSGSIZE, /* SCPI_ERR_SIZE */
358 	-EINVAL, /* SCPI_ERR_HANDLER */
359 	-EACCES, /* SCPI_ERR_ACCESS */
360 	-ERANGE, /* SCPI_ERR_RANGE */
361 	-ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
362 	-ENOMEM, /* SCPI_ERR_NOMEM */
363 	-EINVAL, /* SCPI_ERR_PWRSTATE */
364 	-EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
365 	-EIO, /* SCPI_ERR_DEVICE */
366 	-EBUSY, /* SCPI_ERR_BUSY */
367 };
368 
369 static inline int scpi_to_linux_errno(int errno)
370 {
371 	if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
372 		return scpi_linux_errmap[errno];
373 	return -EIO;
374 }
375 
376 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
377 {
378 	unsigned long flags;
379 	struct scpi_xfer *t, *match = NULL;
380 
381 	spin_lock_irqsave(&ch->rx_lock, flags);
382 	if (list_empty(&ch->rx_pending)) {
383 		spin_unlock_irqrestore(&ch->rx_lock, flags);
384 		return;
385 	}
386 
387 	/* Command type is not replied by the SCP Firmware in legacy Mode
388 	 * We should consider that command is the head of pending RX commands
389 	 * if the list is not empty. In TX only mode, the list would be empty.
390 	 */
391 	if (scpi_info->is_legacy) {
392 		match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
393 					 node);
394 		list_del(&match->node);
395 	} else {
396 		list_for_each_entry(t, &ch->rx_pending, node)
397 			if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
398 				list_del(&t->node);
399 				match = t;
400 				break;
401 			}
402 	}
403 	/* check if wait_for_completion is in progress or timed-out */
404 	if (match && !completion_done(&match->done)) {
405 		unsigned int len;
406 
407 		if (scpi_info->is_legacy) {
408 			struct legacy_scpi_shared_mem __iomem *mem =
409 							ch->rx_payload;
410 
411 			/* RX Length is not replied by the legacy Firmware */
412 			len = match->rx_len;
413 
414 			match->status = ioread32(&mem->status);
415 			memcpy_fromio(match->rx_buf, mem->payload, len);
416 		} else {
417 			struct scpi_shared_mem __iomem *mem = ch->rx_payload;
418 
419 			len = min(match->rx_len, CMD_SIZE(cmd));
420 
421 			match->status = ioread32(&mem->status);
422 			memcpy_fromio(match->rx_buf, mem->payload, len);
423 		}
424 
425 		if (match->rx_len > len)
426 			memset(match->rx_buf + len, 0, match->rx_len - len);
427 		complete(&match->done);
428 	}
429 	spin_unlock_irqrestore(&ch->rx_lock, flags);
430 }
431 
432 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
433 {
434 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
435 	struct scpi_shared_mem __iomem *mem = ch->rx_payload;
436 	u32 cmd = 0;
437 
438 	if (!scpi_info->is_legacy)
439 		cmd = ioread32(&mem->command);
440 
441 	scpi_process_cmd(ch, cmd);
442 }
443 
444 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
445 {
446 	unsigned long flags;
447 	struct scpi_xfer *t = msg;
448 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
449 	struct scpi_shared_mem __iomem *mem = ch->tx_payload;
450 
451 	if (t->tx_buf) {
452 		if (scpi_info->is_legacy)
453 			memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
454 		else
455 			memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
456 	}
457 
458 	if (t->rx_buf) {
459 		if (!(++ch->token))
460 			++ch->token;
461 		ADD_SCPI_TOKEN(t->cmd, ch->token);
462 		spin_lock_irqsave(&ch->rx_lock, flags);
463 		list_add_tail(&t->node, &ch->rx_pending);
464 		spin_unlock_irqrestore(&ch->rx_lock, flags);
465 	}
466 
467 	if (!scpi_info->is_legacy)
468 		iowrite32(t->cmd, &mem->command);
469 }
470 
471 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
472 {
473 	struct scpi_xfer *t;
474 
475 	mutex_lock(&ch->xfers_lock);
476 	if (list_empty(&ch->xfers_list)) {
477 		mutex_unlock(&ch->xfers_lock);
478 		return NULL;
479 	}
480 	t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
481 	list_del(&t->node);
482 	mutex_unlock(&ch->xfers_lock);
483 	return t;
484 }
485 
486 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
487 {
488 	mutex_lock(&ch->xfers_lock);
489 	list_add_tail(&t->node, &ch->xfers_list);
490 	mutex_unlock(&ch->xfers_lock);
491 }
492 
493 static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
494 			     void *rx_buf, unsigned int rx_len)
495 {
496 	int ret;
497 	u8 chan;
498 	u8 cmd;
499 	struct scpi_xfer *msg;
500 	struct scpi_chan *scpi_chan;
501 
502 	if (scpi_info->commands[idx] < 0)
503 		return -EOPNOTSUPP;
504 
505 	cmd = scpi_info->commands[idx];
506 
507 	if (scpi_info->is_legacy)
508 		chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
509 	else
510 		chan = atomic_inc_return(&scpi_info->next_chan) %
511 			scpi_info->num_chans;
512 	scpi_chan = scpi_info->channels + chan;
513 
514 	msg = get_scpi_xfer(scpi_chan);
515 	if (!msg)
516 		return -ENOMEM;
517 
518 	if (scpi_info->is_legacy) {
519 		msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
520 		msg->slot = msg->cmd;
521 	} else {
522 		msg->slot = BIT(SCPI_SLOT);
523 		msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
524 	}
525 	msg->tx_buf = tx_buf;
526 	msg->tx_len = tx_len;
527 	msg->rx_buf = rx_buf;
528 	msg->rx_len = rx_len;
529 	reinit_completion(&msg->done);
530 
531 	ret = mbox_send_message(scpi_chan->chan, msg);
532 	if (ret < 0 || !rx_buf)
533 		goto out;
534 
535 	if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
536 		ret = -ETIMEDOUT;
537 	else
538 		/* first status word */
539 		ret = msg->status;
540 out:
541 	if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
542 		scpi_process_cmd(scpi_chan, msg->cmd);
543 
544 	put_scpi_xfer(msg, scpi_chan);
545 	/* SCPI error codes > 0, translate them to Linux scale*/
546 	return ret > 0 ? scpi_to_linux_errno(ret) : ret;
547 }
548 
549 static u32 scpi_get_version(void)
550 {
551 	return scpi_info->protocol_version;
552 }
553 
554 static int
555 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
556 {
557 	int ret;
558 	struct clk_get_info clk;
559 	__le16 le_clk_id = cpu_to_le16(clk_id);
560 
561 	ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
562 				sizeof(le_clk_id), &clk, sizeof(clk));
563 	if (!ret) {
564 		*min = le32_to_cpu(clk.min_rate);
565 		*max = le32_to_cpu(clk.max_rate);
566 	}
567 	return ret;
568 }
569 
570 static unsigned long scpi_clk_get_val(u16 clk_id)
571 {
572 	int ret;
573 	__le32 rate;
574 	__le16 le_clk_id = cpu_to_le16(clk_id);
575 
576 	ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
577 				sizeof(le_clk_id), &rate, sizeof(rate));
578 
579 	return ret ? ret : le32_to_cpu(rate);
580 }
581 
582 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
583 {
584 	int stat;
585 	struct 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 legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
595 {
596 	int stat;
597 	struct legacy_clk_set_value clk = {
598 		.id = cpu_to_le16(clk_id),
599 		.rate = cpu_to_le32(rate)
600 	};
601 
602 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
603 				 &stat, sizeof(stat));
604 }
605 
606 static int scpi_dvfs_get_idx(u8 domain)
607 {
608 	int ret;
609 	u8 dvfs_idx;
610 
611 	ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
612 				&dvfs_idx, sizeof(dvfs_idx));
613 
614 	return ret ? ret : dvfs_idx;
615 }
616 
617 static int scpi_dvfs_set_idx(u8 domain, u8 index)
618 {
619 	int stat;
620 	struct dvfs_set dvfs = {domain, index};
621 
622 	return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
623 				 &stat, sizeof(stat));
624 }
625 
626 static int opp_cmp_func(const void *opp1, const void *opp2)
627 {
628 	const struct scpi_opp *t1 = opp1, *t2 = opp2;
629 
630 	return t1->freq - t2->freq;
631 }
632 
633 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
634 {
635 	if (domain >= MAX_DVFS_DOMAINS)
636 		return ERR_PTR(-EINVAL);
637 
638 	return scpi_info->dvfs[domain] ?: ERR_PTR(-EINVAL);
639 }
640 
641 static int scpi_dvfs_populate_info(struct device *dev, u8 domain)
642 {
643 	struct scpi_dvfs_info *info;
644 	struct scpi_opp *opp;
645 	struct dvfs_info buf;
646 	int ret, i;
647 
648 	ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
649 				&buf, sizeof(buf));
650 	if (ret)
651 		return ret;
652 
653 	info = devm_kmalloc(dev, sizeof(*info), GFP_KERNEL);
654 	if (!info)
655 		return -ENOMEM;
656 
657 	info->count = buf.opp_count;
658 	info->latency = le16_to_cpu(buf.latency) * 1000; /* uS to nS */
659 
660 	info->opps = devm_kcalloc(dev, info->count, sizeof(*opp), GFP_KERNEL);
661 	if (!info->opps)
662 		return -ENOMEM;
663 
664 	for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
665 		opp->freq = le32_to_cpu(buf.opps[i].freq);
666 		opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
667 	}
668 
669 	sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
670 
671 	scpi_info->dvfs[domain] = info;
672 	return 0;
673 }
674 
675 static void scpi_dvfs_populate(struct device *dev)
676 {
677 	int domain;
678 
679 	for (domain = 0; domain < MAX_DVFS_DOMAINS; domain++)
680 		scpi_dvfs_populate_info(dev, domain);
681 }
682 
683 static int scpi_dev_domain_id(struct device *dev)
684 {
685 	struct of_phandle_args clkspec;
686 
687 	if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
688 				       0, &clkspec))
689 		return -EINVAL;
690 
691 	return clkspec.args[0];
692 }
693 
694 static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
695 {
696 	int domain = scpi_dev_domain_id(dev);
697 
698 	if (domain < 0)
699 		return ERR_PTR(domain);
700 
701 	return scpi_dvfs_get_info(domain);
702 }
703 
704 static int scpi_dvfs_get_transition_latency(struct device *dev)
705 {
706 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
707 
708 	if (IS_ERR(info))
709 		return PTR_ERR(info);
710 
711 	return info->latency;
712 }
713 
714 static int scpi_dvfs_add_opps_to_device(struct device *dev)
715 {
716 	int idx, ret;
717 	struct scpi_opp *opp;
718 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
719 
720 	if (IS_ERR(info))
721 		return PTR_ERR(info);
722 
723 	if (!info->opps)
724 		return -EIO;
725 
726 	for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
727 		ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
728 		if (ret) {
729 			dev_warn(dev, "failed to add opp %uHz %umV\n",
730 				 opp->freq, opp->m_volt);
731 			while (idx-- > 0)
732 				dev_pm_opp_remove(dev, (--opp)->freq);
733 			return ret;
734 		}
735 	}
736 	return 0;
737 }
738 
739 static int scpi_sensor_get_capability(u16 *sensors)
740 {
741 	struct sensor_capabilities cap_buf;
742 	int ret;
743 
744 	ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
745 				sizeof(cap_buf));
746 	if (!ret)
747 		*sensors = le16_to_cpu(cap_buf.sensors);
748 
749 	return ret;
750 }
751 
752 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
753 {
754 	__le16 id = cpu_to_le16(sensor_id);
755 	struct _scpi_sensor_info _info;
756 	int ret;
757 
758 	ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
759 				&_info, sizeof(_info));
760 	if (!ret) {
761 		memcpy(info, &_info, sizeof(*info));
762 		info->sensor_id = le16_to_cpu(_info.sensor_id);
763 	}
764 
765 	return ret;
766 }
767 
768 static int scpi_sensor_get_value(u16 sensor, u64 *val)
769 {
770 	__le16 id = cpu_to_le16(sensor);
771 	__le64 value;
772 	int ret;
773 
774 	ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
775 				&value, sizeof(value));
776 	if (ret)
777 		return ret;
778 
779 	if (scpi_info->is_legacy)
780 		/* only 32-bits supported, upper 32 bits can be junk */
781 		*val = le32_to_cpup((__le32 *)&value);
782 	else
783 		*val = le64_to_cpu(value);
784 
785 	return 0;
786 }
787 
788 static int scpi_device_get_power_state(u16 dev_id)
789 {
790 	int ret;
791 	u8 pstate;
792 	__le16 id = cpu_to_le16(dev_id);
793 
794 	ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
795 				sizeof(id), &pstate, sizeof(pstate));
796 	return ret ? ret : pstate;
797 }
798 
799 static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
800 {
801 	int stat;
802 	struct dev_pstate_set dev_set = {
803 		.dev_id = cpu_to_le16(dev_id),
804 		.pstate = pstate,
805 	};
806 
807 	return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
808 				 sizeof(dev_set), &stat, sizeof(stat));
809 }
810 
811 static struct scpi_ops scpi_ops = {
812 	.get_version = scpi_get_version,
813 	.clk_get_range = scpi_clk_get_range,
814 	.clk_get_val = scpi_clk_get_val,
815 	.clk_set_val = scpi_clk_set_val,
816 	.dvfs_get_idx = scpi_dvfs_get_idx,
817 	.dvfs_set_idx = scpi_dvfs_set_idx,
818 	.dvfs_get_info = scpi_dvfs_get_info,
819 	.device_domain_id = scpi_dev_domain_id,
820 	.get_transition_latency = scpi_dvfs_get_transition_latency,
821 	.add_opps_to_device = scpi_dvfs_add_opps_to_device,
822 	.sensor_get_capability = scpi_sensor_get_capability,
823 	.sensor_get_info = scpi_sensor_get_info,
824 	.sensor_get_value = scpi_sensor_get_value,
825 	.device_get_power_state = scpi_device_get_power_state,
826 	.device_set_power_state = scpi_device_set_power_state,
827 };
828 
829 struct scpi_ops *get_scpi_ops(void)
830 {
831 	return scpi_info ? scpi_info->scpi_ops : NULL;
832 }
833 EXPORT_SYMBOL_GPL(get_scpi_ops);
834 
835 static int scpi_init_versions(struct scpi_drvinfo *info)
836 {
837 	int ret;
838 	struct scp_capabilities caps;
839 
840 	ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
841 				&caps, sizeof(caps));
842 	if (!ret) {
843 		info->protocol_version = le32_to_cpu(caps.protocol_version);
844 		info->firmware_version = le32_to_cpu(caps.platform_version);
845 	}
846 	/* Ignore error if not implemented */
847 	if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
848 		return 0;
849 
850 	return ret;
851 }
852 
853 static ssize_t protocol_version_show(struct device *dev,
854 				     struct device_attribute *attr, char *buf)
855 {
856 	return sprintf(buf, "%lu.%lu\n",
857 		FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
858 		FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version));
859 }
860 static DEVICE_ATTR_RO(protocol_version);
861 
862 static ssize_t firmware_version_show(struct device *dev,
863 				     struct device_attribute *attr, char *buf)
864 {
865 	return sprintf(buf, "%lu.%lu.%lu\n",
866 		     FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
867 		     FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
868 		     FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
869 }
870 static DEVICE_ATTR_RO(firmware_version);
871 
872 static struct attribute *versions_attrs[] = {
873 	&dev_attr_firmware_version.attr,
874 	&dev_attr_protocol_version.attr,
875 	NULL,
876 };
877 ATTRIBUTE_GROUPS(versions);
878 
879 static void scpi_free_channels(void *data)
880 {
881 	struct scpi_drvinfo *info = data;
882 	int i;
883 
884 	for (i = 0; i < info->num_chans; i++)
885 		mbox_free_channel(info->channels[i].chan);
886 }
887 
888 #define MAX_SCPI_XFERS		10
889 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
890 {
891 	int i;
892 	struct scpi_xfer *xfers;
893 
894 	xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
895 	if (!xfers)
896 		return -ENOMEM;
897 
898 	ch->xfers = xfers;
899 	for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
900 		init_completion(&xfers->done);
901 		list_add_tail(&xfers->node, &ch->xfers_list);
902 	}
903 
904 	return 0;
905 }
906 
907 static const struct of_device_id legacy_scpi_of_match[] = {
908 	{.compatible = "arm,scpi-pre-1.0"},
909 	{},
910 };
911 
912 static int scpi_probe(struct platform_device *pdev)
913 {
914 	int count, idx, ret;
915 	struct resource res;
916 	struct device *dev = &pdev->dev;
917 	struct device_node *np = dev->of_node;
918 
919 	scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
920 	if (!scpi_info)
921 		return -ENOMEM;
922 
923 	if (of_match_device(legacy_scpi_of_match, &pdev->dev))
924 		scpi_info->is_legacy = true;
925 
926 	count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
927 	if (count < 0) {
928 		dev_err(dev, "no mboxes property in '%pOF'\n", np);
929 		return -ENODEV;
930 	}
931 
932 	scpi_info->channels = devm_kcalloc(dev, count, sizeof(struct scpi_chan),
933 					   GFP_KERNEL);
934 	if (!scpi_info->channels)
935 		return -ENOMEM;
936 
937 	ret = devm_add_action(dev, scpi_free_channels, scpi_info);
938 	if (ret)
939 		return ret;
940 
941 	for (; scpi_info->num_chans < count; scpi_info->num_chans++) {
942 		resource_size_t size;
943 		int idx = scpi_info->num_chans;
944 		struct scpi_chan *pchan = scpi_info->channels + idx;
945 		struct mbox_client *cl = &pchan->cl;
946 		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
947 
948 		ret = of_address_to_resource(shmem, 0, &res);
949 		of_node_put(shmem);
950 		if (ret) {
951 			dev_err(dev, "failed to get SCPI payload mem resource\n");
952 			return ret;
953 		}
954 
955 		size = resource_size(&res);
956 		pchan->rx_payload = devm_ioremap(dev, res.start, size);
957 		if (!pchan->rx_payload) {
958 			dev_err(dev, "failed to ioremap SCPI payload\n");
959 			return -EADDRNOTAVAIL;
960 		}
961 		pchan->tx_payload = pchan->rx_payload + (size >> 1);
962 
963 		cl->dev = dev;
964 		cl->rx_callback = scpi_handle_remote_msg;
965 		cl->tx_prepare = scpi_tx_prepare;
966 		cl->tx_block = true;
967 		cl->tx_tout = 20;
968 		cl->knows_txdone = false; /* controller can't ack */
969 
970 		INIT_LIST_HEAD(&pchan->rx_pending);
971 		INIT_LIST_HEAD(&pchan->xfers_list);
972 		spin_lock_init(&pchan->rx_lock);
973 		mutex_init(&pchan->xfers_lock);
974 
975 		ret = scpi_alloc_xfer_list(dev, pchan);
976 		if (!ret) {
977 			pchan->chan = mbox_request_channel(cl, idx);
978 			if (!IS_ERR(pchan->chan))
979 				continue;
980 			ret = PTR_ERR(pchan->chan);
981 			if (ret != -EPROBE_DEFER)
982 				dev_err(dev, "failed to get channel%d err %d\n",
983 					idx, ret);
984 		}
985 		return ret;
986 	}
987 
988 	scpi_info->commands = scpi_std_commands;
989 	scpi_info->scpi_ops = &scpi_ops;
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 	scpi_dvfs_populate(dev);
1009 
1010 	_dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1011 		  FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
1012 		  FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version),
1013 		  FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
1014 		  FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
1015 		  FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
1016 
1017 	ret = devm_device_add_groups(dev, versions_groups);
1018 	if (ret)
1019 		dev_err(dev, "unable to create sysfs version group\n");
1020 
1021 	return devm_of_platform_populate(dev);
1022 }
1023 
1024 static const struct of_device_id scpi_of_match[] = {
1025 	{.compatible = "arm,scpi"},
1026 	{.compatible = "arm,scpi-pre-1.0"},
1027 	{},
1028 };
1029 
1030 MODULE_DEVICE_TABLE(of, scpi_of_match);
1031 
1032 static struct platform_driver scpi_driver = {
1033 	.driver = {
1034 		.name = "scpi_protocol",
1035 		.of_match_table = scpi_of_match,
1036 	},
1037 	.probe = scpi_probe,
1038 };
1039 module_platform_driver(scpi_driver);
1040 
1041 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1042 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1043 MODULE_LICENSE("GPL v2");
1044