xref: /linux/drivers/firmware/arm_scpi.c (revision a23e1966932464e1c5226cb9ac4ce1d5fc10ba22)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * System Control and Power Interface (SCPI) Message Protocol driver
4  *
5  * SCPI Message Protocol is used between the System Control Processor(SCP)
6  * and the Application Processors(AP). The Message Handling Unit(MHU)
7  * provides a mechanism for inter-processor communication between SCP's
8  * Cortex M3 and AP.
9  *
10  * SCP offers control and management of the core/cluster power states,
11  * various power domain DVFS including the core/cluster, certain system
12  * clocks configuration, thermal sensors and many others.
13  *
14  * Copyright (C) 2015 ARM Ltd.
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <linux/bitmap.h>
20 #include <linux/bitfield.h>
21 #include <linux/device.h>
22 #include <linux/err.h>
23 #include <linux/export.h>
24 #include <linux/io.h>
25 #include <linux/kernel.h>
26 #include <linux/list.h>
27 #include <linux/mailbox_client.h>
28 #include <linux/module.h>
29 #include <linux/of.h>
30 #include <linux/of_address.h>
31 #include <linux/of_platform.h>
32 #include <linux/platform_device.h>
33 #include <linux/printk.h>
34 #include <linux/property.h>
35 #include <linux/pm_opp.h>
36 #include <linux/scpi_protocol.h>
37 #include <linux/slab.h>
38 #include <linux/sort.h>
39 #include <linux/spinlock.h>
40 
41 #define CMD_ID_MASK		GENMASK(6, 0)
42 #define CMD_TOKEN_ID_MASK	GENMASK(15, 8)
43 #define CMD_DATA_SIZE_MASK	GENMASK(24, 16)
44 #define CMD_LEGACY_DATA_SIZE_MASK	GENMASK(28, 20)
45 #define PACK_SCPI_CMD(cmd_id, tx_sz)		\
46 	(FIELD_PREP(CMD_ID_MASK, cmd_id) |	\
47 	FIELD_PREP(CMD_DATA_SIZE_MASK, tx_sz))
48 #define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)	\
49 	(FIELD_PREP(CMD_ID_MASK, cmd_id) |	\
50 	FIELD_PREP(CMD_LEGACY_DATA_SIZE_MASK, tx_sz))
51 
52 #define CMD_SIZE(cmd)	FIELD_GET(CMD_DATA_SIZE_MASK, cmd)
53 #define CMD_UNIQ_MASK	(CMD_TOKEN_ID_MASK | CMD_ID_MASK)
54 #define CMD_XTRACT_UNIQ(cmd)	((cmd) & CMD_UNIQ_MASK)
55 
56 #define SCPI_SLOT		0
57 
58 #define MAX_DVFS_DOMAINS	8
59 #define MAX_DVFS_OPPS		16
60 
61 #define PROTO_REV_MAJOR_MASK	GENMASK(31, 16)
62 #define PROTO_REV_MINOR_MASK	GENMASK(15, 0)
63 
64 #define FW_REV_MAJOR_MASK	GENMASK(31, 24)
65 #define FW_REV_MINOR_MASK	GENMASK(23, 16)
66 #define FW_REV_PATCH_MASK	GENMASK(15, 0)
67 
68 #define MAX_RX_TIMEOUT		(msecs_to_jiffies(30))
69 
70 enum scpi_error_codes {
71 	SCPI_SUCCESS = 0, /* Success */
72 	SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
73 	SCPI_ERR_ALIGN = 2, /* Invalid alignment */
74 	SCPI_ERR_SIZE = 3, /* Invalid size */
75 	SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
76 	SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
77 	SCPI_ERR_RANGE = 6, /* Value out of range */
78 	SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
79 	SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
80 	SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
81 	SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
82 	SCPI_ERR_DEVICE = 11, /* Device error */
83 	SCPI_ERR_BUSY = 12, /* Device busy */
84 	SCPI_ERR_MAX
85 };
86 
87 /* SCPI Standard commands */
88 enum scpi_std_cmd {
89 	SCPI_CMD_INVALID		= 0x00,
90 	SCPI_CMD_SCPI_READY		= 0x01,
91 	SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
92 	SCPI_CMD_SET_CSS_PWR_STATE	= 0x03,
93 	SCPI_CMD_GET_CSS_PWR_STATE	= 0x04,
94 	SCPI_CMD_SET_SYS_PWR_STATE	= 0x05,
95 	SCPI_CMD_SET_CPU_TIMER		= 0x06,
96 	SCPI_CMD_CANCEL_CPU_TIMER	= 0x07,
97 	SCPI_CMD_DVFS_CAPABILITIES	= 0x08,
98 	SCPI_CMD_GET_DVFS_INFO		= 0x09,
99 	SCPI_CMD_SET_DVFS		= 0x0a,
100 	SCPI_CMD_GET_DVFS		= 0x0b,
101 	SCPI_CMD_GET_DVFS_STAT		= 0x0c,
102 	SCPI_CMD_CLOCK_CAPABILITIES	= 0x0d,
103 	SCPI_CMD_GET_CLOCK_INFO		= 0x0e,
104 	SCPI_CMD_SET_CLOCK_VALUE	= 0x0f,
105 	SCPI_CMD_GET_CLOCK_VALUE	= 0x10,
106 	SCPI_CMD_PSU_CAPABILITIES	= 0x11,
107 	SCPI_CMD_GET_PSU_INFO		= 0x12,
108 	SCPI_CMD_SET_PSU		= 0x13,
109 	SCPI_CMD_GET_PSU		= 0x14,
110 	SCPI_CMD_SENSOR_CAPABILITIES	= 0x15,
111 	SCPI_CMD_SENSOR_INFO		= 0x16,
112 	SCPI_CMD_SENSOR_VALUE		= 0x17,
113 	SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x18,
114 	SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x19,
115 	SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1a,
116 	SCPI_CMD_SET_DEVICE_PWR_STATE	= 0x1b,
117 	SCPI_CMD_GET_DEVICE_PWR_STATE	= 0x1c,
118 	SCPI_CMD_COUNT
119 };
120 
121 /* SCPI Legacy Commands */
122 enum legacy_scpi_std_cmd {
123 	LEGACY_SCPI_CMD_INVALID			= 0x00,
124 	LEGACY_SCPI_CMD_SCPI_READY		= 0x01,
125 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
126 	LEGACY_SCPI_CMD_EVENT			= 0x03,
127 	LEGACY_SCPI_CMD_SET_CSS_PWR_STATE	= 0x04,
128 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE	= 0x05,
129 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT	= 0x06,
130 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT	= 0x07,
131 	LEGACY_SCPI_CMD_SYS_PWR_STATE		= 0x08,
132 	LEGACY_SCPI_CMD_L2_READY		= 0x09,
133 	LEGACY_SCPI_CMD_SET_AP_TIMER		= 0x0a,
134 	LEGACY_SCPI_CMD_CANCEL_AP_TIME		= 0x0b,
135 	LEGACY_SCPI_CMD_DVFS_CAPABILITIES	= 0x0c,
136 	LEGACY_SCPI_CMD_GET_DVFS_INFO		= 0x0d,
137 	LEGACY_SCPI_CMD_SET_DVFS		= 0x0e,
138 	LEGACY_SCPI_CMD_GET_DVFS		= 0x0f,
139 	LEGACY_SCPI_CMD_GET_DVFS_STAT		= 0x10,
140 	LEGACY_SCPI_CMD_SET_RTC			= 0x11,
141 	LEGACY_SCPI_CMD_GET_RTC			= 0x12,
142 	LEGACY_SCPI_CMD_CLOCK_CAPABILITIES	= 0x13,
143 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX		= 0x14,
144 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE		= 0x15,
145 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE		= 0x16,
146 	LEGACY_SCPI_CMD_PSU_CAPABILITIES	= 0x17,
147 	LEGACY_SCPI_CMD_SET_PSU			= 0x18,
148 	LEGACY_SCPI_CMD_GET_PSU			= 0x19,
149 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES	= 0x1a,
150 	LEGACY_SCPI_CMD_SENSOR_INFO		= 0x1b,
151 	LEGACY_SCPI_CMD_SENSOR_VALUE		= 0x1c,
152 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x1d,
153 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x1e,
154 	LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1f,
155 	LEGACY_SCPI_CMD_COUNT
156 };
157 
158 /* List all commands that are required to go through the high priority link */
159 static int legacy_hpriority_cmds[] = {
160 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
161 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
162 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
163 	LEGACY_SCPI_CMD_SET_DVFS,
164 	LEGACY_SCPI_CMD_GET_DVFS,
165 	LEGACY_SCPI_CMD_SET_RTC,
166 	LEGACY_SCPI_CMD_GET_RTC,
167 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
168 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
169 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
170 	LEGACY_SCPI_CMD_SET_PSU,
171 	LEGACY_SCPI_CMD_GET_PSU,
172 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
173 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
174 };
175 
176 /* List all commands used by this driver, used as indexes */
177 enum scpi_drv_cmds {
178 	CMD_SCPI_CAPABILITIES = 0,
179 	CMD_GET_CLOCK_INFO,
180 	CMD_GET_CLOCK_VALUE,
181 	CMD_SET_CLOCK_VALUE,
182 	CMD_GET_DVFS,
183 	CMD_SET_DVFS,
184 	CMD_GET_DVFS_INFO,
185 	CMD_SENSOR_CAPABILITIES,
186 	CMD_SENSOR_INFO,
187 	CMD_SENSOR_VALUE,
188 	CMD_SET_DEVICE_PWR_STATE,
189 	CMD_GET_DEVICE_PWR_STATE,
190 	CMD_MAX_COUNT,
191 };
192 
193 static int scpi_std_commands[CMD_MAX_COUNT] = {
194 	SCPI_CMD_SCPI_CAPABILITIES,
195 	SCPI_CMD_GET_CLOCK_INFO,
196 	SCPI_CMD_GET_CLOCK_VALUE,
197 	SCPI_CMD_SET_CLOCK_VALUE,
198 	SCPI_CMD_GET_DVFS,
199 	SCPI_CMD_SET_DVFS,
200 	SCPI_CMD_GET_DVFS_INFO,
201 	SCPI_CMD_SENSOR_CAPABILITIES,
202 	SCPI_CMD_SENSOR_INFO,
203 	SCPI_CMD_SENSOR_VALUE,
204 	SCPI_CMD_SET_DEVICE_PWR_STATE,
205 	SCPI_CMD_GET_DEVICE_PWR_STATE,
206 };
207 
208 static int scpi_legacy_commands[CMD_MAX_COUNT] = {
209 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
210 	-1, /* GET_CLOCK_INFO */
211 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
212 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
213 	LEGACY_SCPI_CMD_GET_DVFS,
214 	LEGACY_SCPI_CMD_SET_DVFS,
215 	LEGACY_SCPI_CMD_GET_DVFS_INFO,
216 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
217 	LEGACY_SCPI_CMD_SENSOR_INFO,
218 	LEGACY_SCPI_CMD_SENSOR_VALUE,
219 	-1, /* SET_DEVICE_PWR_STATE */
220 	-1, /* GET_DEVICE_PWR_STATE */
221 };
222 
223 struct scpi_xfer {
224 	u32 slot; /* has to be first element */
225 	u32 cmd;
226 	u32 status;
227 	const void *tx_buf;
228 	void *rx_buf;
229 	unsigned int tx_len;
230 	unsigned int rx_len;
231 	struct list_head node;
232 	struct completion done;
233 };
234 
235 struct scpi_chan {
236 	struct mbox_client cl;
237 	struct mbox_chan *chan;
238 	void __iomem *tx_payload;
239 	void __iomem *rx_payload;
240 	struct list_head rx_pending;
241 	struct list_head xfers_list;
242 	struct scpi_xfer *xfers;
243 	spinlock_t rx_lock; /* locking for the rx pending list */
244 	struct mutex xfers_lock;
245 	u8 token;
246 };
247 
248 struct scpi_drvinfo {
249 	u32 protocol_version;
250 	u32 firmware_version;
251 	bool is_legacy;
252 	int num_chans;
253 	int *commands;
254 	DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
255 	atomic_t next_chan;
256 	struct scpi_ops *scpi_ops;
257 	struct scpi_chan *channels;
258 	struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
259 };
260 
261 /*
262  * The SCP firmware only executes in little-endian mode, so any buffers
263  * shared through SCPI should have their contents converted to little-endian
264  */
265 struct scpi_shared_mem {
266 	__le32 command;
267 	__le32 status;
268 	u8 payload[];
269 } __packed;
270 
271 struct legacy_scpi_shared_mem {
272 	__le32 status;
273 	u8 payload[];
274 } __packed;
275 
276 struct scp_capabilities {
277 	__le32 protocol_version;
278 	__le32 event_version;
279 	__le32 platform_version;
280 	__le32 commands[4];
281 } __packed;
282 
283 struct clk_get_info {
284 	__le16 id;
285 	__le16 flags;
286 	__le32 min_rate;
287 	__le32 max_rate;
288 	u8 name[20];
289 } __packed;
290 
291 struct clk_set_value {
292 	__le16 id;
293 	__le16 reserved;
294 	__le32 rate;
295 } __packed;
296 
297 struct legacy_clk_set_value {
298 	__le32 rate;
299 	__le16 id;
300 	__le16 reserved;
301 } __packed;
302 
303 struct dvfs_info {
304 	u8 domain;
305 	u8 opp_count;
306 	__le16 latency;
307 	struct {
308 		__le32 freq;
309 		__le32 m_volt;
310 	} opps[MAX_DVFS_OPPS];
311 } __packed;
312 
313 struct dvfs_set {
314 	u8 domain;
315 	u8 index;
316 } __packed;
317 
318 struct _scpi_sensor_info {
319 	__le16 sensor_id;
320 	u8 class;
321 	u8 trigger_type;
322 	char name[20];
323 };
324 
325 struct dev_pstate_set {
326 	__le16 dev_id;
327 	u8 pstate;
328 } __packed;
329 
330 static struct scpi_drvinfo *scpi_info;
331 
332 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
333 	/* better than switch case as long as return value is continuous */
334 	0, /* SCPI_SUCCESS */
335 	-EINVAL, /* SCPI_ERR_PARAM */
336 	-ENOEXEC, /* SCPI_ERR_ALIGN */
337 	-EMSGSIZE, /* SCPI_ERR_SIZE */
338 	-EINVAL, /* SCPI_ERR_HANDLER */
339 	-EACCES, /* SCPI_ERR_ACCESS */
340 	-ERANGE, /* SCPI_ERR_RANGE */
341 	-ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
342 	-ENOMEM, /* SCPI_ERR_NOMEM */
343 	-EINVAL, /* SCPI_ERR_PWRSTATE */
344 	-EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
345 	-EIO, /* SCPI_ERR_DEVICE */
346 	-EBUSY, /* SCPI_ERR_BUSY */
347 };
348 
349 static inline int scpi_to_linux_errno(int errno)
350 {
351 	if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
352 		return scpi_linux_errmap[errno];
353 	return -EIO;
354 }
355 
356 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
357 {
358 	unsigned long flags;
359 	struct scpi_xfer *t, *match = NULL;
360 
361 	spin_lock_irqsave(&ch->rx_lock, flags);
362 	if (list_empty(&ch->rx_pending)) {
363 		spin_unlock_irqrestore(&ch->rx_lock, flags);
364 		return;
365 	}
366 
367 	/* Command type is not replied by the SCP Firmware in legacy Mode
368 	 * We should consider that command is the head of pending RX commands
369 	 * if the list is not empty. In TX only mode, the list would be empty.
370 	 */
371 	if (scpi_info->is_legacy) {
372 		match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
373 					 node);
374 		list_del(&match->node);
375 	} else {
376 		list_for_each_entry(t, &ch->rx_pending, node)
377 			if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
378 				list_del(&t->node);
379 				match = t;
380 				break;
381 			}
382 	}
383 	/* check if wait_for_completion is in progress or timed-out */
384 	if (match && !completion_done(&match->done)) {
385 		unsigned int len;
386 
387 		if (scpi_info->is_legacy) {
388 			struct legacy_scpi_shared_mem __iomem *mem =
389 							ch->rx_payload;
390 
391 			/* RX Length is not replied by the legacy Firmware */
392 			len = match->rx_len;
393 
394 			match->status = ioread32(&mem->status);
395 			memcpy_fromio(match->rx_buf, mem->payload, len);
396 		} else {
397 			struct scpi_shared_mem __iomem *mem = ch->rx_payload;
398 
399 			len = min_t(unsigned int, match->rx_len, CMD_SIZE(cmd));
400 
401 			match->status = ioread32(&mem->status);
402 			memcpy_fromio(match->rx_buf, mem->payload, len);
403 		}
404 
405 		if (match->rx_len > len)
406 			memset(match->rx_buf + len, 0, match->rx_len - len);
407 		complete(&match->done);
408 	}
409 	spin_unlock_irqrestore(&ch->rx_lock, flags);
410 }
411 
412 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
413 {
414 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
415 	struct scpi_shared_mem __iomem *mem = ch->rx_payload;
416 	u32 cmd = 0;
417 
418 	if (!scpi_info->is_legacy)
419 		cmd = ioread32(&mem->command);
420 
421 	scpi_process_cmd(ch, cmd);
422 }
423 
424 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
425 {
426 	unsigned long flags;
427 	struct scpi_xfer *t = msg;
428 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
429 	struct scpi_shared_mem __iomem *mem = ch->tx_payload;
430 
431 	if (t->tx_buf) {
432 		if (scpi_info->is_legacy)
433 			memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
434 		else
435 			memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
436 	}
437 
438 	if (t->rx_buf) {
439 		if (!(++ch->token))
440 			++ch->token;
441 		t->cmd |= FIELD_PREP(CMD_TOKEN_ID_MASK, ch->token);
442 		spin_lock_irqsave(&ch->rx_lock, flags);
443 		list_add_tail(&t->node, &ch->rx_pending);
444 		spin_unlock_irqrestore(&ch->rx_lock, flags);
445 	}
446 
447 	if (!scpi_info->is_legacy)
448 		iowrite32(t->cmd, &mem->command);
449 }
450 
451 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
452 {
453 	struct scpi_xfer *t;
454 
455 	mutex_lock(&ch->xfers_lock);
456 	if (list_empty(&ch->xfers_list)) {
457 		mutex_unlock(&ch->xfers_lock);
458 		return NULL;
459 	}
460 	t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
461 	list_del(&t->node);
462 	mutex_unlock(&ch->xfers_lock);
463 	return t;
464 }
465 
466 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
467 {
468 	mutex_lock(&ch->xfers_lock);
469 	list_add_tail(&t->node, &ch->xfers_list);
470 	mutex_unlock(&ch->xfers_lock);
471 }
472 
473 static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
474 			     void *rx_buf, unsigned int rx_len)
475 {
476 	int ret;
477 	u8 chan;
478 	u8 cmd;
479 	struct scpi_xfer *msg;
480 	struct scpi_chan *scpi_chan;
481 
482 	if (scpi_info->commands[idx] < 0)
483 		return -EOPNOTSUPP;
484 
485 	cmd = scpi_info->commands[idx];
486 
487 	if (scpi_info->is_legacy)
488 		chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
489 	else
490 		chan = atomic_inc_return(&scpi_info->next_chan) %
491 			scpi_info->num_chans;
492 	scpi_chan = scpi_info->channels + chan;
493 
494 	msg = get_scpi_xfer(scpi_chan);
495 	if (!msg)
496 		return -ENOMEM;
497 
498 	if (scpi_info->is_legacy) {
499 		msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
500 		msg->slot = msg->cmd;
501 	} else {
502 		msg->slot = BIT(SCPI_SLOT);
503 		msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
504 	}
505 	msg->tx_buf = tx_buf;
506 	msg->tx_len = tx_len;
507 	msg->rx_buf = rx_buf;
508 	msg->rx_len = rx_len;
509 	reinit_completion(&msg->done);
510 
511 	ret = mbox_send_message(scpi_chan->chan, msg);
512 	if (ret < 0 || !rx_buf)
513 		goto out;
514 
515 	if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
516 		ret = -ETIMEDOUT;
517 	else
518 		/* first status word */
519 		ret = msg->status;
520 out:
521 	if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
522 		scpi_process_cmd(scpi_chan, msg->cmd);
523 
524 	put_scpi_xfer(msg, scpi_chan);
525 	/* SCPI error codes > 0, translate them to Linux scale*/
526 	return ret > 0 ? scpi_to_linux_errno(ret) : ret;
527 }
528 
529 static u32 scpi_get_version(void)
530 {
531 	return scpi_info->protocol_version;
532 }
533 
534 static int
535 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
536 {
537 	int ret;
538 	struct clk_get_info clk;
539 	__le16 le_clk_id = cpu_to_le16(clk_id);
540 
541 	ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
542 				sizeof(le_clk_id), &clk, sizeof(clk));
543 	if (!ret) {
544 		*min = le32_to_cpu(clk.min_rate);
545 		*max = le32_to_cpu(clk.max_rate);
546 	}
547 	return ret;
548 }
549 
550 static unsigned long scpi_clk_get_val(u16 clk_id)
551 {
552 	int ret;
553 	__le32 rate;
554 	__le16 le_clk_id = cpu_to_le16(clk_id);
555 
556 	ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
557 				sizeof(le_clk_id), &rate, sizeof(rate));
558 	if (ret)
559 		return 0;
560 
561 	return le32_to_cpu(rate);
562 }
563 
564 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
565 {
566 	int stat;
567 	struct clk_set_value clk = {
568 		.id = cpu_to_le16(clk_id),
569 		.rate = cpu_to_le32(rate)
570 	};
571 
572 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
573 				 &stat, sizeof(stat));
574 }
575 
576 static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
577 {
578 	int stat;
579 	struct legacy_clk_set_value clk = {
580 		.id = cpu_to_le16(clk_id),
581 		.rate = cpu_to_le32(rate)
582 	};
583 
584 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
585 				 &stat, sizeof(stat));
586 }
587 
588 static int scpi_dvfs_get_idx(u8 domain)
589 {
590 	int ret;
591 	u8 dvfs_idx;
592 
593 	ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
594 				&dvfs_idx, sizeof(dvfs_idx));
595 
596 	return ret ? ret : dvfs_idx;
597 }
598 
599 static int scpi_dvfs_set_idx(u8 domain, u8 index)
600 {
601 	int stat;
602 	struct dvfs_set dvfs = {domain, index};
603 
604 	return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
605 				 &stat, sizeof(stat));
606 }
607 
608 static int opp_cmp_func(const void *opp1, const void *opp2)
609 {
610 	const struct scpi_opp *t1 = opp1, *t2 = opp2;
611 
612 	return t1->freq - t2->freq;
613 }
614 
615 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
616 {
617 	struct scpi_dvfs_info *info;
618 	struct scpi_opp *opp;
619 	struct dvfs_info buf;
620 	int ret, i;
621 
622 	if (domain >= MAX_DVFS_DOMAINS)
623 		return ERR_PTR(-EINVAL);
624 
625 	if (scpi_info->dvfs[domain])	/* data already populated */
626 		return scpi_info->dvfs[domain];
627 
628 	ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
629 				&buf, sizeof(buf));
630 	if (ret)
631 		return ERR_PTR(ret);
632 
633 	info = kmalloc(sizeof(*info), GFP_KERNEL);
634 	if (!info)
635 		return ERR_PTR(-ENOMEM);
636 
637 	info->count = buf.opp_count;
638 	info->latency = le16_to_cpu(buf.latency) * 1000; /* uS to nS */
639 
640 	info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
641 	if (!info->opps) {
642 		kfree(info);
643 		return ERR_PTR(-ENOMEM);
644 	}
645 
646 	for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
647 		opp->freq = le32_to_cpu(buf.opps[i].freq);
648 		opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
649 	}
650 
651 	sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
652 
653 	scpi_info->dvfs[domain] = info;
654 	return info;
655 }
656 
657 static int scpi_dev_domain_id(struct device *dev)
658 {
659 	struct of_phandle_args clkspec;
660 
661 	if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
662 				       0, &clkspec))
663 		return -EINVAL;
664 
665 	return clkspec.args[0];
666 }
667 
668 static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
669 {
670 	int domain = scpi_dev_domain_id(dev);
671 
672 	if (domain < 0)
673 		return ERR_PTR(domain);
674 
675 	return scpi_dvfs_get_info(domain);
676 }
677 
678 static int scpi_dvfs_get_transition_latency(struct device *dev)
679 {
680 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
681 
682 	if (IS_ERR(info))
683 		return PTR_ERR(info);
684 
685 	return info->latency;
686 }
687 
688 static int scpi_dvfs_add_opps_to_device(struct device *dev)
689 {
690 	int idx, ret;
691 	struct scpi_opp *opp;
692 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
693 
694 	if (IS_ERR(info))
695 		return PTR_ERR(info);
696 
697 	if (!info->opps)
698 		return -EIO;
699 
700 	for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
701 		ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
702 		if (ret) {
703 			dev_warn(dev, "failed to add opp %uHz %umV\n",
704 				 opp->freq, opp->m_volt);
705 			while (idx-- > 0)
706 				dev_pm_opp_remove(dev, (--opp)->freq);
707 			return ret;
708 		}
709 	}
710 	return 0;
711 }
712 
713 static int scpi_sensor_get_capability(u16 *sensors)
714 {
715 	__le16 cap;
716 	int ret;
717 
718 	ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap,
719 				sizeof(cap));
720 	if (!ret)
721 		*sensors = le16_to_cpu(cap);
722 
723 	return ret;
724 }
725 
726 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
727 {
728 	__le16 id = cpu_to_le16(sensor_id);
729 	struct _scpi_sensor_info _info;
730 	int ret;
731 
732 	ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
733 				&_info, sizeof(_info));
734 	if (!ret) {
735 		memcpy(info, &_info, sizeof(*info));
736 		info->sensor_id = le16_to_cpu(_info.sensor_id);
737 	}
738 
739 	return ret;
740 }
741 
742 static int scpi_sensor_get_value(u16 sensor, u64 *val)
743 {
744 	__le16 id = cpu_to_le16(sensor);
745 	__le64 value;
746 	int ret;
747 
748 	ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
749 				&value, sizeof(value));
750 	if (ret)
751 		return ret;
752 
753 	if (scpi_info->is_legacy)
754 		/* only 32-bits supported, upper 32 bits can be junk */
755 		*val = le32_to_cpup((__le32 *)&value);
756 	else
757 		*val = le64_to_cpu(value);
758 
759 	return 0;
760 }
761 
762 static int scpi_device_get_power_state(u16 dev_id)
763 {
764 	int ret;
765 	u8 pstate;
766 	__le16 id = cpu_to_le16(dev_id);
767 
768 	ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
769 				sizeof(id), &pstate, sizeof(pstate));
770 	return ret ? ret : pstate;
771 }
772 
773 static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
774 {
775 	int stat;
776 	struct dev_pstate_set dev_set = {
777 		.dev_id = cpu_to_le16(dev_id),
778 		.pstate = pstate,
779 	};
780 
781 	return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
782 				 sizeof(dev_set), &stat, sizeof(stat));
783 }
784 
785 static struct scpi_ops scpi_ops = {
786 	.get_version = scpi_get_version,
787 	.clk_get_range = scpi_clk_get_range,
788 	.clk_get_val = scpi_clk_get_val,
789 	.clk_set_val = scpi_clk_set_val,
790 	.dvfs_get_idx = scpi_dvfs_get_idx,
791 	.dvfs_set_idx = scpi_dvfs_set_idx,
792 	.dvfs_get_info = scpi_dvfs_get_info,
793 	.device_domain_id = scpi_dev_domain_id,
794 	.get_transition_latency = scpi_dvfs_get_transition_latency,
795 	.add_opps_to_device = scpi_dvfs_add_opps_to_device,
796 	.sensor_get_capability = scpi_sensor_get_capability,
797 	.sensor_get_info = scpi_sensor_get_info,
798 	.sensor_get_value = scpi_sensor_get_value,
799 	.device_get_power_state = scpi_device_get_power_state,
800 	.device_set_power_state = scpi_device_set_power_state,
801 };
802 
803 struct scpi_ops *get_scpi_ops(void)
804 {
805 	return scpi_info ? scpi_info->scpi_ops : NULL;
806 }
807 EXPORT_SYMBOL_GPL(get_scpi_ops);
808 
809 static int scpi_init_versions(struct scpi_drvinfo *info)
810 {
811 	int ret;
812 	struct scp_capabilities caps;
813 
814 	ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
815 				&caps, sizeof(caps));
816 	if (!ret) {
817 		info->protocol_version = le32_to_cpu(caps.protocol_version);
818 		info->firmware_version = le32_to_cpu(caps.platform_version);
819 	}
820 	/* Ignore error if not implemented */
821 	if (info->is_legacy && ret == -EOPNOTSUPP)
822 		return 0;
823 
824 	return ret;
825 }
826 
827 static ssize_t protocol_version_show(struct device *dev,
828 				     struct device_attribute *attr, char *buf)
829 {
830 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
831 
832 	return sprintf(buf, "%lu.%lu\n",
833 		FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
834 		FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version));
835 }
836 static DEVICE_ATTR_RO(protocol_version);
837 
838 static ssize_t firmware_version_show(struct device *dev,
839 				     struct device_attribute *attr, char *buf)
840 {
841 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
842 
843 	return sprintf(buf, "%lu.%lu.%lu\n",
844 		FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
845 		FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
846 		FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
847 }
848 static DEVICE_ATTR_RO(firmware_version);
849 
850 static struct attribute *versions_attrs[] = {
851 	&dev_attr_firmware_version.attr,
852 	&dev_attr_protocol_version.attr,
853 	NULL,
854 };
855 ATTRIBUTE_GROUPS(versions);
856 
857 static void scpi_free_channels(void *data)
858 {
859 	struct scpi_drvinfo *info = data;
860 	int i;
861 
862 	for (i = 0; i < info->num_chans; i++)
863 		mbox_free_channel(info->channels[i].chan);
864 }
865 
866 static void scpi_remove(struct platform_device *pdev)
867 {
868 	int i;
869 	struct scpi_drvinfo *info = platform_get_drvdata(pdev);
870 
871 	scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
872 
873 	for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
874 		kfree(info->dvfs[i]->opps);
875 		kfree(info->dvfs[i]);
876 	}
877 }
878 
879 #define MAX_SCPI_XFERS		10
880 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
881 {
882 	int i;
883 	struct scpi_xfer *xfers;
884 
885 	xfers = devm_kcalloc(dev, MAX_SCPI_XFERS, sizeof(*xfers), GFP_KERNEL);
886 	if (!xfers)
887 		return -ENOMEM;
888 
889 	ch->xfers = xfers;
890 	for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
891 		init_completion(&xfers->done);
892 		list_add_tail(&xfers->node, &ch->xfers_list);
893 	}
894 
895 	return 0;
896 }
897 
898 static const struct of_device_id shmem_of_match[] __maybe_unused = {
899 	{ .compatible = "amlogic,meson-gxbb-scp-shmem", },
900 	{ .compatible = "amlogic,meson-axg-scp-shmem", },
901 	{ .compatible = "arm,juno-scp-shmem", },
902 	{ .compatible = "arm,scp-shmem", },
903 	{ }
904 };
905 
906 static int scpi_probe(struct platform_device *pdev)
907 {
908 	int count, idx, ret;
909 	struct resource res;
910 	struct device *dev = &pdev->dev;
911 	struct device_node *np = dev->of_node;
912 	struct scpi_drvinfo *scpi_drvinfo;
913 
914 	scpi_drvinfo = devm_kzalloc(dev, sizeof(*scpi_drvinfo), GFP_KERNEL);
915 	if (!scpi_drvinfo)
916 		return -ENOMEM;
917 
918 	scpi_drvinfo->is_legacy = !!device_get_match_data(dev);
919 
920 	count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
921 	if (count < 0) {
922 		dev_err(dev, "no mboxes property in '%pOF'\n", np);
923 		return -ENODEV;
924 	}
925 
926 	scpi_drvinfo->channels =
927 		devm_kcalloc(dev, count, sizeof(struct scpi_chan), GFP_KERNEL);
928 	if (!scpi_drvinfo->channels)
929 		return -ENOMEM;
930 
931 	ret = devm_add_action(dev, scpi_free_channels, scpi_drvinfo);
932 	if (ret)
933 		return ret;
934 
935 	for (; scpi_drvinfo->num_chans < count; scpi_drvinfo->num_chans++) {
936 		resource_size_t size;
937 		int idx = scpi_drvinfo->num_chans;
938 		struct scpi_chan *pchan = scpi_drvinfo->channels + idx;
939 		struct mbox_client *cl = &pchan->cl;
940 		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
941 
942 		if (!of_match_node(shmem_of_match, shmem))
943 			return -ENXIO;
944 
945 		ret = of_address_to_resource(shmem, 0, &res);
946 		of_node_put(shmem);
947 		if (ret) {
948 			dev_err(dev, "failed to get SCPI payload mem resource\n");
949 			return ret;
950 		}
951 
952 		size = resource_size(&res);
953 		pchan->rx_payload = devm_ioremap(dev, res.start, size);
954 		if (!pchan->rx_payload) {
955 			dev_err(dev, "failed to ioremap SCPI payload\n");
956 			return -EADDRNOTAVAIL;
957 		}
958 		pchan->tx_payload = pchan->rx_payload + (size >> 1);
959 
960 		cl->dev = dev;
961 		cl->rx_callback = scpi_handle_remote_msg;
962 		cl->tx_prepare = scpi_tx_prepare;
963 		cl->tx_block = true;
964 		cl->tx_tout = 20;
965 		cl->knows_txdone = false; /* controller can't ack */
966 
967 		INIT_LIST_HEAD(&pchan->rx_pending);
968 		INIT_LIST_HEAD(&pchan->xfers_list);
969 		spin_lock_init(&pchan->rx_lock);
970 		mutex_init(&pchan->xfers_lock);
971 
972 		ret = scpi_alloc_xfer_list(dev, pchan);
973 		if (!ret) {
974 			pchan->chan = mbox_request_channel(cl, idx);
975 			if (!IS_ERR(pchan->chan))
976 				continue;
977 			ret = PTR_ERR(pchan->chan);
978 			if (ret != -EPROBE_DEFER)
979 				dev_err(dev, "failed to get channel%d err %d\n",
980 					idx, ret);
981 		}
982 		return ret;
983 	}
984 
985 	scpi_drvinfo->commands = scpi_std_commands;
986 
987 	platform_set_drvdata(pdev, scpi_drvinfo);
988 
989 	if (scpi_drvinfo->is_legacy) {
990 		/* Replace with legacy variants */
991 		scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
992 		scpi_drvinfo->commands = scpi_legacy_commands;
993 
994 		/* Fill priority bitmap */
995 		for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
996 			set_bit(legacy_hpriority_cmds[idx],
997 				scpi_drvinfo->cmd_priority);
998 	}
999 
1000 	scpi_info = scpi_drvinfo;
1001 
1002 	ret = scpi_init_versions(scpi_drvinfo);
1003 	if (ret) {
1004 		dev_err(dev, "incorrect or no SCP firmware found\n");
1005 		scpi_info = NULL;
1006 		return ret;
1007 	}
1008 
1009 	if (scpi_drvinfo->is_legacy && !scpi_drvinfo->protocol_version &&
1010 	    !scpi_drvinfo->firmware_version)
1011 		dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
1012 	else
1013 		dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1014 			 FIELD_GET(PROTO_REV_MAJOR_MASK,
1015 				   scpi_drvinfo->protocol_version),
1016 			 FIELD_GET(PROTO_REV_MINOR_MASK,
1017 				   scpi_drvinfo->protocol_version),
1018 			 FIELD_GET(FW_REV_MAJOR_MASK,
1019 				   scpi_drvinfo->firmware_version),
1020 			 FIELD_GET(FW_REV_MINOR_MASK,
1021 				   scpi_drvinfo->firmware_version),
1022 			 FIELD_GET(FW_REV_PATCH_MASK,
1023 				   scpi_drvinfo->firmware_version));
1024 
1025 	scpi_drvinfo->scpi_ops = &scpi_ops;
1026 
1027 	ret = devm_of_platform_populate(dev);
1028 	if (ret)
1029 		scpi_info = NULL;
1030 
1031 	return ret;
1032 }
1033 
1034 static const struct of_device_id scpi_of_match[] = {
1035 	{.compatible = "arm,scpi"},
1036 	{.compatible = "arm,scpi-pre-1.0", .data = (void *)1UL },
1037 	{},
1038 };
1039 
1040 MODULE_DEVICE_TABLE(of, scpi_of_match);
1041 
1042 static struct platform_driver scpi_driver = {
1043 	.driver = {
1044 		.name = "scpi_protocol",
1045 		.of_match_table = scpi_of_match,
1046 		.dev_groups = versions_groups,
1047 	},
1048 	.probe = scpi_probe,
1049 	.remove_new = scpi_remove,
1050 };
1051 module_platform_driver(scpi_driver);
1052 
1053 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1054 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1055 MODULE_LICENSE("GPL v2");
1056