xref: /openbmc/linux/drivers/firmware/arm_scpi.c (revision 0c29e149)
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_address.h>
30 #include <linux/of_platform.h>
31 #include <linux/printk.h>
32 #include <linux/pm_opp.h>
33 #include <linux/scpi_protocol.h>
34 #include <linux/slab.h>
35 #include <linux/sort.h>
36 #include <linux/spinlock.h>
37 
38 #define CMD_ID_MASK		GENMASK(6, 0)
39 #define CMD_TOKEN_ID_MASK	GENMASK(15, 8)
40 #define CMD_DATA_SIZE_MASK	GENMASK(24, 16)
41 #define CMD_LEGACY_DATA_SIZE_MASK	GENMASK(28, 20)
42 #define PACK_SCPI_CMD(cmd_id, tx_sz)		\
43 	(FIELD_PREP(CMD_ID_MASK, cmd_id) |	\
44 	FIELD_PREP(CMD_DATA_SIZE_MASK, tx_sz))
45 #define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)	\
46 	(FIELD_PREP(CMD_ID_MASK, cmd_id) |	\
47 	FIELD_PREP(CMD_LEGACY_DATA_SIZE_MASK, tx_sz))
48 
49 #define CMD_SIZE(cmd)	FIELD_GET(CMD_DATA_SIZE_MASK, cmd)
50 #define CMD_UNIQ_MASK	(CMD_TOKEN_ID_MASK | CMD_ID_MASK)
51 #define CMD_XTRACT_UNIQ(cmd)	((cmd) & CMD_UNIQ_MASK)
52 
53 #define SCPI_SLOT		0
54 
55 #define MAX_DVFS_DOMAINS	8
56 #define MAX_DVFS_OPPS		16
57 
58 #define PROTO_REV_MAJOR_MASK	GENMASK(31, 16)
59 #define PROTO_REV_MINOR_MASK	GENMASK(15, 0)
60 
61 #define FW_REV_MAJOR_MASK	GENMASK(31, 24)
62 #define FW_REV_MINOR_MASK	GENMASK(23, 16)
63 #define FW_REV_PATCH_MASK	GENMASK(15, 0)
64 
65 #define MAX_RX_TIMEOUT		(msecs_to_jiffies(30))
66 
67 enum scpi_error_codes {
68 	SCPI_SUCCESS = 0, /* Success */
69 	SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
70 	SCPI_ERR_ALIGN = 2, /* Invalid alignment */
71 	SCPI_ERR_SIZE = 3, /* Invalid size */
72 	SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
73 	SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
74 	SCPI_ERR_RANGE = 6, /* Value out of range */
75 	SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
76 	SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
77 	SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
78 	SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
79 	SCPI_ERR_DEVICE = 11, /* Device error */
80 	SCPI_ERR_BUSY = 12, /* Device busy */
81 	SCPI_ERR_MAX
82 };
83 
84 /* SCPI Standard commands */
85 enum scpi_std_cmd {
86 	SCPI_CMD_INVALID		= 0x00,
87 	SCPI_CMD_SCPI_READY		= 0x01,
88 	SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
89 	SCPI_CMD_SET_CSS_PWR_STATE	= 0x03,
90 	SCPI_CMD_GET_CSS_PWR_STATE	= 0x04,
91 	SCPI_CMD_SET_SYS_PWR_STATE	= 0x05,
92 	SCPI_CMD_SET_CPU_TIMER		= 0x06,
93 	SCPI_CMD_CANCEL_CPU_TIMER	= 0x07,
94 	SCPI_CMD_DVFS_CAPABILITIES	= 0x08,
95 	SCPI_CMD_GET_DVFS_INFO		= 0x09,
96 	SCPI_CMD_SET_DVFS		= 0x0a,
97 	SCPI_CMD_GET_DVFS		= 0x0b,
98 	SCPI_CMD_GET_DVFS_STAT		= 0x0c,
99 	SCPI_CMD_CLOCK_CAPABILITIES	= 0x0d,
100 	SCPI_CMD_GET_CLOCK_INFO		= 0x0e,
101 	SCPI_CMD_SET_CLOCK_VALUE	= 0x0f,
102 	SCPI_CMD_GET_CLOCK_VALUE	= 0x10,
103 	SCPI_CMD_PSU_CAPABILITIES	= 0x11,
104 	SCPI_CMD_GET_PSU_INFO		= 0x12,
105 	SCPI_CMD_SET_PSU		= 0x13,
106 	SCPI_CMD_GET_PSU		= 0x14,
107 	SCPI_CMD_SENSOR_CAPABILITIES	= 0x15,
108 	SCPI_CMD_SENSOR_INFO		= 0x16,
109 	SCPI_CMD_SENSOR_VALUE		= 0x17,
110 	SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x18,
111 	SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x19,
112 	SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1a,
113 	SCPI_CMD_SET_DEVICE_PWR_STATE	= 0x1b,
114 	SCPI_CMD_GET_DEVICE_PWR_STATE	= 0x1c,
115 	SCPI_CMD_COUNT
116 };
117 
118 /* SCPI Legacy Commands */
119 enum legacy_scpi_std_cmd {
120 	LEGACY_SCPI_CMD_INVALID			= 0x00,
121 	LEGACY_SCPI_CMD_SCPI_READY		= 0x01,
122 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
123 	LEGACY_SCPI_CMD_EVENT			= 0x03,
124 	LEGACY_SCPI_CMD_SET_CSS_PWR_STATE	= 0x04,
125 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE	= 0x05,
126 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT	= 0x06,
127 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT	= 0x07,
128 	LEGACY_SCPI_CMD_SYS_PWR_STATE		= 0x08,
129 	LEGACY_SCPI_CMD_L2_READY		= 0x09,
130 	LEGACY_SCPI_CMD_SET_AP_TIMER		= 0x0a,
131 	LEGACY_SCPI_CMD_CANCEL_AP_TIME		= 0x0b,
132 	LEGACY_SCPI_CMD_DVFS_CAPABILITIES	= 0x0c,
133 	LEGACY_SCPI_CMD_GET_DVFS_INFO		= 0x0d,
134 	LEGACY_SCPI_CMD_SET_DVFS		= 0x0e,
135 	LEGACY_SCPI_CMD_GET_DVFS		= 0x0f,
136 	LEGACY_SCPI_CMD_GET_DVFS_STAT		= 0x10,
137 	LEGACY_SCPI_CMD_SET_RTC			= 0x11,
138 	LEGACY_SCPI_CMD_GET_RTC			= 0x12,
139 	LEGACY_SCPI_CMD_CLOCK_CAPABILITIES	= 0x13,
140 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX		= 0x14,
141 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE		= 0x15,
142 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE		= 0x16,
143 	LEGACY_SCPI_CMD_PSU_CAPABILITIES	= 0x17,
144 	LEGACY_SCPI_CMD_SET_PSU			= 0x18,
145 	LEGACY_SCPI_CMD_GET_PSU			= 0x19,
146 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES	= 0x1a,
147 	LEGACY_SCPI_CMD_SENSOR_INFO		= 0x1b,
148 	LEGACY_SCPI_CMD_SENSOR_VALUE		= 0x1c,
149 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x1d,
150 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x1e,
151 	LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1f,
152 	LEGACY_SCPI_CMD_COUNT
153 };
154 
155 /* List all commands that are required to go through the high priority link */
156 static int legacy_hpriority_cmds[] = {
157 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
158 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
159 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
160 	LEGACY_SCPI_CMD_SET_DVFS,
161 	LEGACY_SCPI_CMD_GET_DVFS,
162 	LEGACY_SCPI_CMD_SET_RTC,
163 	LEGACY_SCPI_CMD_GET_RTC,
164 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
165 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
166 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
167 	LEGACY_SCPI_CMD_SET_PSU,
168 	LEGACY_SCPI_CMD_GET_PSU,
169 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
170 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
171 };
172 
173 /* List all commands used by this driver, used as indexes */
174 enum scpi_drv_cmds {
175 	CMD_SCPI_CAPABILITIES = 0,
176 	CMD_GET_CLOCK_INFO,
177 	CMD_GET_CLOCK_VALUE,
178 	CMD_SET_CLOCK_VALUE,
179 	CMD_GET_DVFS,
180 	CMD_SET_DVFS,
181 	CMD_GET_DVFS_INFO,
182 	CMD_SENSOR_CAPABILITIES,
183 	CMD_SENSOR_INFO,
184 	CMD_SENSOR_VALUE,
185 	CMD_SET_DEVICE_PWR_STATE,
186 	CMD_GET_DEVICE_PWR_STATE,
187 	CMD_MAX_COUNT,
188 };
189 
190 static int scpi_std_commands[CMD_MAX_COUNT] = {
191 	SCPI_CMD_SCPI_CAPABILITIES,
192 	SCPI_CMD_GET_CLOCK_INFO,
193 	SCPI_CMD_GET_CLOCK_VALUE,
194 	SCPI_CMD_SET_CLOCK_VALUE,
195 	SCPI_CMD_GET_DVFS,
196 	SCPI_CMD_SET_DVFS,
197 	SCPI_CMD_GET_DVFS_INFO,
198 	SCPI_CMD_SENSOR_CAPABILITIES,
199 	SCPI_CMD_SENSOR_INFO,
200 	SCPI_CMD_SENSOR_VALUE,
201 	SCPI_CMD_SET_DEVICE_PWR_STATE,
202 	SCPI_CMD_GET_DEVICE_PWR_STATE,
203 };
204 
205 static int scpi_legacy_commands[CMD_MAX_COUNT] = {
206 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
207 	-1, /* GET_CLOCK_INFO */
208 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
209 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
210 	LEGACY_SCPI_CMD_GET_DVFS,
211 	LEGACY_SCPI_CMD_SET_DVFS,
212 	LEGACY_SCPI_CMD_GET_DVFS_INFO,
213 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
214 	LEGACY_SCPI_CMD_SENSOR_INFO,
215 	LEGACY_SCPI_CMD_SENSOR_VALUE,
216 	-1, /* SET_DEVICE_PWR_STATE */
217 	-1, /* GET_DEVICE_PWR_STATE */
218 };
219 
220 struct scpi_xfer {
221 	u32 slot; /* has to be first element */
222 	u32 cmd;
223 	u32 status;
224 	const void *tx_buf;
225 	void *rx_buf;
226 	unsigned int tx_len;
227 	unsigned int rx_len;
228 	struct list_head node;
229 	struct completion done;
230 };
231 
232 struct scpi_chan {
233 	struct mbox_client cl;
234 	struct mbox_chan *chan;
235 	void __iomem *tx_payload;
236 	void __iomem *rx_payload;
237 	struct list_head rx_pending;
238 	struct list_head xfers_list;
239 	struct scpi_xfer *xfers;
240 	spinlock_t rx_lock; /* locking for the rx pending list */
241 	struct mutex xfers_lock;
242 	u8 token;
243 };
244 
245 struct scpi_drvinfo {
246 	u32 protocol_version;
247 	u32 firmware_version;
248 	bool is_legacy;
249 	int num_chans;
250 	int *commands;
251 	DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
252 	atomic_t next_chan;
253 	struct scpi_ops *scpi_ops;
254 	struct scpi_chan *channels;
255 	struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
256 };
257 
258 /*
259  * The SCP firmware only executes in little-endian mode, so any buffers
260  * shared through SCPI should have their contents converted to little-endian
261  */
262 struct scpi_shared_mem {
263 	__le32 command;
264 	__le32 status;
265 	u8 payload[];
266 } __packed;
267 
268 struct legacy_scpi_shared_mem {
269 	__le32 status;
270 	u8 payload[];
271 } __packed;
272 
273 struct scp_capabilities {
274 	__le32 protocol_version;
275 	__le32 event_version;
276 	__le32 platform_version;
277 	__le32 commands[4];
278 } __packed;
279 
280 struct clk_get_info {
281 	__le16 id;
282 	__le16 flags;
283 	__le32 min_rate;
284 	__le32 max_rate;
285 	u8 name[20];
286 } __packed;
287 
288 struct clk_set_value {
289 	__le16 id;
290 	__le16 reserved;
291 	__le32 rate;
292 } __packed;
293 
294 struct legacy_clk_set_value {
295 	__le32 rate;
296 	__le16 id;
297 	__le16 reserved;
298 } __packed;
299 
300 struct dvfs_info {
301 	u8 domain;
302 	u8 opp_count;
303 	__le16 latency;
304 	struct {
305 		__le32 freq;
306 		__le32 m_volt;
307 	} opps[MAX_DVFS_OPPS];
308 } __packed;
309 
310 struct dvfs_set {
311 	u8 domain;
312 	u8 index;
313 } __packed;
314 
315 struct _scpi_sensor_info {
316 	__le16 sensor_id;
317 	u8 class;
318 	u8 trigger_type;
319 	char name[20];
320 };
321 
322 struct dev_pstate_set {
323 	__le16 dev_id;
324 	u8 pstate;
325 } __packed;
326 
327 static struct scpi_drvinfo *scpi_info;
328 
329 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
330 	/* better than switch case as long as return value is continuous */
331 	0, /* SCPI_SUCCESS */
332 	-EINVAL, /* SCPI_ERR_PARAM */
333 	-ENOEXEC, /* SCPI_ERR_ALIGN */
334 	-EMSGSIZE, /* SCPI_ERR_SIZE */
335 	-EINVAL, /* SCPI_ERR_HANDLER */
336 	-EACCES, /* SCPI_ERR_ACCESS */
337 	-ERANGE, /* SCPI_ERR_RANGE */
338 	-ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
339 	-ENOMEM, /* SCPI_ERR_NOMEM */
340 	-EINVAL, /* SCPI_ERR_PWRSTATE */
341 	-EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
342 	-EIO, /* SCPI_ERR_DEVICE */
343 	-EBUSY, /* SCPI_ERR_BUSY */
344 };
345 
scpi_to_linux_errno(int errno)346 static inline int scpi_to_linux_errno(int errno)
347 {
348 	if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
349 		return scpi_linux_errmap[errno];
350 	return -EIO;
351 }
352 
scpi_process_cmd(struct scpi_chan * ch,u32 cmd)353 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
354 {
355 	unsigned long flags;
356 	struct scpi_xfer *t, *match = NULL;
357 
358 	spin_lock_irqsave(&ch->rx_lock, flags);
359 	if (list_empty(&ch->rx_pending)) {
360 		spin_unlock_irqrestore(&ch->rx_lock, flags);
361 		return;
362 	}
363 
364 	/* Command type is not replied by the SCP Firmware in legacy Mode
365 	 * We should consider that command is the head of pending RX commands
366 	 * if the list is not empty. In TX only mode, the list would be empty.
367 	 */
368 	if (scpi_info->is_legacy) {
369 		match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
370 					 node);
371 		list_del(&match->node);
372 	} else {
373 		list_for_each_entry(t, &ch->rx_pending, node)
374 			if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
375 				list_del(&t->node);
376 				match = t;
377 				break;
378 			}
379 	}
380 	/* check if wait_for_completion is in progress or timed-out */
381 	if (match && !completion_done(&match->done)) {
382 		unsigned int len;
383 
384 		if (scpi_info->is_legacy) {
385 			struct legacy_scpi_shared_mem __iomem *mem =
386 							ch->rx_payload;
387 
388 			/* RX Length is not replied by the legacy Firmware */
389 			len = match->rx_len;
390 
391 			match->status = ioread32(&mem->status);
392 			memcpy_fromio(match->rx_buf, mem->payload, len);
393 		} else {
394 			struct scpi_shared_mem __iomem *mem = ch->rx_payload;
395 
396 			len = min_t(unsigned int, match->rx_len, CMD_SIZE(cmd));
397 
398 			match->status = ioread32(&mem->status);
399 			memcpy_fromio(match->rx_buf, mem->payload, len);
400 		}
401 
402 		if (match->rx_len > len)
403 			memset(match->rx_buf + len, 0, match->rx_len - len);
404 		complete(&match->done);
405 	}
406 	spin_unlock_irqrestore(&ch->rx_lock, flags);
407 }
408 
scpi_handle_remote_msg(struct mbox_client * c,void * msg)409 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
410 {
411 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
412 	struct scpi_shared_mem __iomem *mem = ch->rx_payload;
413 	u32 cmd = 0;
414 
415 	if (!scpi_info->is_legacy)
416 		cmd = ioread32(&mem->command);
417 
418 	scpi_process_cmd(ch, cmd);
419 }
420 
scpi_tx_prepare(struct mbox_client * c,void * msg)421 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
422 {
423 	unsigned long flags;
424 	struct scpi_xfer *t = msg;
425 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
426 	struct scpi_shared_mem __iomem *mem = ch->tx_payload;
427 
428 	if (t->tx_buf) {
429 		if (scpi_info->is_legacy)
430 			memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
431 		else
432 			memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
433 	}
434 
435 	if (t->rx_buf) {
436 		if (!(++ch->token))
437 			++ch->token;
438 		t->cmd |= FIELD_PREP(CMD_TOKEN_ID_MASK, ch->token);
439 		spin_lock_irqsave(&ch->rx_lock, flags);
440 		list_add_tail(&t->node, &ch->rx_pending);
441 		spin_unlock_irqrestore(&ch->rx_lock, flags);
442 	}
443 
444 	if (!scpi_info->is_legacy)
445 		iowrite32(t->cmd, &mem->command);
446 }
447 
get_scpi_xfer(struct scpi_chan * ch)448 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
449 {
450 	struct scpi_xfer *t;
451 
452 	mutex_lock(&ch->xfers_lock);
453 	if (list_empty(&ch->xfers_list)) {
454 		mutex_unlock(&ch->xfers_lock);
455 		return NULL;
456 	}
457 	t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
458 	list_del(&t->node);
459 	mutex_unlock(&ch->xfers_lock);
460 	return t;
461 }
462 
put_scpi_xfer(struct scpi_xfer * t,struct scpi_chan * ch)463 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
464 {
465 	mutex_lock(&ch->xfers_lock);
466 	list_add_tail(&t->node, &ch->xfers_list);
467 	mutex_unlock(&ch->xfers_lock);
468 }
469 
scpi_send_message(u8 idx,void * tx_buf,unsigned int tx_len,void * rx_buf,unsigned int rx_len)470 static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
471 			     void *rx_buf, unsigned int rx_len)
472 {
473 	int ret;
474 	u8 chan;
475 	u8 cmd;
476 	struct scpi_xfer *msg;
477 	struct scpi_chan *scpi_chan;
478 
479 	if (scpi_info->commands[idx] < 0)
480 		return -EOPNOTSUPP;
481 
482 	cmd = scpi_info->commands[idx];
483 
484 	if (scpi_info->is_legacy)
485 		chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
486 	else
487 		chan = atomic_inc_return(&scpi_info->next_chan) %
488 			scpi_info->num_chans;
489 	scpi_chan = scpi_info->channels + chan;
490 
491 	msg = get_scpi_xfer(scpi_chan);
492 	if (!msg)
493 		return -ENOMEM;
494 
495 	if (scpi_info->is_legacy) {
496 		msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
497 		msg->slot = msg->cmd;
498 	} else {
499 		msg->slot = BIT(SCPI_SLOT);
500 		msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
501 	}
502 	msg->tx_buf = tx_buf;
503 	msg->tx_len = tx_len;
504 	msg->rx_buf = rx_buf;
505 	msg->rx_len = rx_len;
506 	reinit_completion(&msg->done);
507 
508 	ret = mbox_send_message(scpi_chan->chan, msg);
509 	if (ret < 0 || !rx_buf)
510 		goto out;
511 
512 	if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
513 		ret = -ETIMEDOUT;
514 	else
515 		/* first status word */
516 		ret = msg->status;
517 out:
518 	if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
519 		scpi_process_cmd(scpi_chan, msg->cmd);
520 
521 	put_scpi_xfer(msg, scpi_chan);
522 	/* SCPI error codes > 0, translate them to Linux scale*/
523 	return ret > 0 ? scpi_to_linux_errno(ret) : ret;
524 }
525 
scpi_get_version(void)526 static u32 scpi_get_version(void)
527 {
528 	return scpi_info->protocol_version;
529 }
530 
531 static int
scpi_clk_get_range(u16 clk_id,unsigned long * min,unsigned long * max)532 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
533 {
534 	int ret;
535 	struct clk_get_info clk;
536 	__le16 le_clk_id = cpu_to_le16(clk_id);
537 
538 	ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
539 				sizeof(le_clk_id), &clk, sizeof(clk));
540 	if (!ret) {
541 		*min = le32_to_cpu(clk.min_rate);
542 		*max = le32_to_cpu(clk.max_rate);
543 	}
544 	return ret;
545 }
546 
scpi_clk_get_val(u16 clk_id)547 static unsigned long scpi_clk_get_val(u16 clk_id)
548 {
549 	int ret;
550 	__le32 rate;
551 	__le16 le_clk_id = cpu_to_le16(clk_id);
552 
553 	ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
554 				sizeof(le_clk_id), &rate, sizeof(rate));
555 	if (ret)
556 		return 0;
557 
558 	return le32_to_cpu(rate);
559 }
560 
scpi_clk_set_val(u16 clk_id,unsigned long rate)561 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
562 {
563 	int stat;
564 	struct clk_set_value clk = {
565 		.id = cpu_to_le16(clk_id),
566 		.rate = cpu_to_le32(rate)
567 	};
568 
569 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
570 				 &stat, sizeof(stat));
571 }
572 
legacy_scpi_clk_set_val(u16 clk_id,unsigned long rate)573 static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
574 {
575 	int stat;
576 	struct legacy_clk_set_value clk = {
577 		.id = cpu_to_le16(clk_id),
578 		.rate = cpu_to_le32(rate)
579 	};
580 
581 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
582 				 &stat, sizeof(stat));
583 }
584 
scpi_dvfs_get_idx(u8 domain)585 static int scpi_dvfs_get_idx(u8 domain)
586 {
587 	int ret;
588 	u8 dvfs_idx;
589 
590 	ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
591 				&dvfs_idx, sizeof(dvfs_idx));
592 
593 	return ret ? ret : dvfs_idx;
594 }
595 
scpi_dvfs_set_idx(u8 domain,u8 index)596 static int scpi_dvfs_set_idx(u8 domain, u8 index)
597 {
598 	int stat;
599 	struct dvfs_set dvfs = {domain, index};
600 
601 	return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
602 				 &stat, sizeof(stat));
603 }
604 
opp_cmp_func(const void * opp1,const void * opp2)605 static int opp_cmp_func(const void *opp1, const void *opp2)
606 {
607 	const struct scpi_opp *t1 = opp1, *t2 = opp2;
608 
609 	return t1->freq - t2->freq;
610 }
611 
scpi_dvfs_get_info(u8 domain)612 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
613 {
614 	struct scpi_dvfs_info *info;
615 	struct scpi_opp *opp;
616 	struct dvfs_info buf;
617 	int ret, i;
618 
619 	if (domain >= MAX_DVFS_DOMAINS)
620 		return ERR_PTR(-EINVAL);
621 
622 	if (scpi_info->dvfs[domain])	/* data already populated */
623 		return scpi_info->dvfs[domain];
624 
625 	ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
626 				&buf, sizeof(buf));
627 	if (ret)
628 		return ERR_PTR(ret);
629 
630 	info = kmalloc(sizeof(*info), GFP_KERNEL);
631 	if (!info)
632 		return ERR_PTR(-ENOMEM);
633 
634 	info->count = buf.opp_count;
635 	info->latency = le16_to_cpu(buf.latency) * 1000; /* uS to nS */
636 
637 	info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
638 	if (!info->opps) {
639 		kfree(info);
640 		return ERR_PTR(-ENOMEM);
641 	}
642 
643 	for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
644 		opp->freq = le32_to_cpu(buf.opps[i].freq);
645 		opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
646 	}
647 
648 	sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
649 
650 	scpi_info->dvfs[domain] = info;
651 	return info;
652 }
653 
scpi_dev_domain_id(struct device * dev)654 static int scpi_dev_domain_id(struct device *dev)
655 {
656 	struct of_phandle_args clkspec;
657 
658 	if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
659 				       0, &clkspec))
660 		return -EINVAL;
661 
662 	return clkspec.args[0];
663 }
664 
scpi_dvfs_info(struct device * dev)665 static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
666 {
667 	int domain = scpi_dev_domain_id(dev);
668 
669 	if (domain < 0)
670 		return ERR_PTR(domain);
671 
672 	return scpi_dvfs_get_info(domain);
673 }
674 
scpi_dvfs_get_transition_latency(struct device * dev)675 static int scpi_dvfs_get_transition_latency(struct device *dev)
676 {
677 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
678 
679 	if (IS_ERR(info))
680 		return PTR_ERR(info);
681 
682 	return info->latency;
683 }
684 
scpi_dvfs_add_opps_to_device(struct device * dev)685 static int scpi_dvfs_add_opps_to_device(struct device *dev)
686 {
687 	int idx, ret;
688 	struct scpi_opp *opp;
689 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
690 
691 	if (IS_ERR(info))
692 		return PTR_ERR(info);
693 
694 	if (!info->opps)
695 		return -EIO;
696 
697 	for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
698 		ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
699 		if (ret) {
700 			dev_warn(dev, "failed to add opp %uHz %umV\n",
701 				 opp->freq, opp->m_volt);
702 			while (idx-- > 0)
703 				dev_pm_opp_remove(dev, (--opp)->freq);
704 			return ret;
705 		}
706 	}
707 	return 0;
708 }
709 
scpi_sensor_get_capability(u16 * sensors)710 static int scpi_sensor_get_capability(u16 *sensors)
711 {
712 	__le16 cap;
713 	int ret;
714 
715 	ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap,
716 				sizeof(cap));
717 	if (!ret)
718 		*sensors = le16_to_cpu(cap);
719 
720 	return ret;
721 }
722 
scpi_sensor_get_info(u16 sensor_id,struct scpi_sensor_info * info)723 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
724 {
725 	__le16 id = cpu_to_le16(sensor_id);
726 	struct _scpi_sensor_info _info;
727 	int ret;
728 
729 	ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
730 				&_info, sizeof(_info));
731 	if (!ret) {
732 		memcpy(info, &_info, sizeof(*info));
733 		info->sensor_id = le16_to_cpu(_info.sensor_id);
734 	}
735 
736 	return ret;
737 }
738 
scpi_sensor_get_value(u16 sensor,u64 * val)739 static int scpi_sensor_get_value(u16 sensor, u64 *val)
740 {
741 	__le16 id = cpu_to_le16(sensor);
742 	__le64 value;
743 	int ret;
744 
745 	ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
746 				&value, sizeof(value));
747 	if (ret)
748 		return ret;
749 
750 	if (scpi_info->is_legacy)
751 		/* only 32-bits supported, upper 32 bits can be junk */
752 		*val = le32_to_cpup((__le32 *)&value);
753 	else
754 		*val = le64_to_cpu(value);
755 
756 	return 0;
757 }
758 
scpi_device_get_power_state(u16 dev_id)759 static int scpi_device_get_power_state(u16 dev_id)
760 {
761 	int ret;
762 	u8 pstate;
763 	__le16 id = cpu_to_le16(dev_id);
764 
765 	ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
766 				sizeof(id), &pstate, sizeof(pstate));
767 	return ret ? ret : pstate;
768 }
769 
scpi_device_set_power_state(u16 dev_id,u8 pstate)770 static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
771 {
772 	int stat;
773 	struct dev_pstate_set dev_set = {
774 		.dev_id = cpu_to_le16(dev_id),
775 		.pstate = pstate,
776 	};
777 
778 	return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
779 				 sizeof(dev_set), &stat, sizeof(stat));
780 }
781 
782 static struct scpi_ops scpi_ops = {
783 	.get_version = scpi_get_version,
784 	.clk_get_range = scpi_clk_get_range,
785 	.clk_get_val = scpi_clk_get_val,
786 	.clk_set_val = scpi_clk_set_val,
787 	.dvfs_get_idx = scpi_dvfs_get_idx,
788 	.dvfs_set_idx = scpi_dvfs_set_idx,
789 	.dvfs_get_info = scpi_dvfs_get_info,
790 	.device_domain_id = scpi_dev_domain_id,
791 	.get_transition_latency = scpi_dvfs_get_transition_latency,
792 	.add_opps_to_device = scpi_dvfs_add_opps_to_device,
793 	.sensor_get_capability = scpi_sensor_get_capability,
794 	.sensor_get_info = scpi_sensor_get_info,
795 	.sensor_get_value = scpi_sensor_get_value,
796 	.device_get_power_state = scpi_device_get_power_state,
797 	.device_set_power_state = scpi_device_set_power_state,
798 };
799 
get_scpi_ops(void)800 struct scpi_ops *get_scpi_ops(void)
801 {
802 	return scpi_info ? scpi_info->scpi_ops : NULL;
803 }
804 EXPORT_SYMBOL_GPL(get_scpi_ops);
805 
scpi_init_versions(struct scpi_drvinfo * info)806 static int scpi_init_versions(struct scpi_drvinfo *info)
807 {
808 	int ret;
809 	struct scp_capabilities caps;
810 
811 	ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
812 				&caps, sizeof(caps));
813 	if (!ret) {
814 		info->protocol_version = le32_to_cpu(caps.protocol_version);
815 		info->firmware_version = le32_to_cpu(caps.platform_version);
816 	}
817 	/* Ignore error if not implemented */
818 	if (info->is_legacy && ret == -EOPNOTSUPP)
819 		return 0;
820 
821 	return ret;
822 }
823 
protocol_version_show(struct device * dev,struct device_attribute * attr,char * buf)824 static ssize_t protocol_version_show(struct device *dev,
825 				     struct device_attribute *attr, char *buf)
826 {
827 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
828 
829 	return sprintf(buf, "%lu.%lu\n",
830 		FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
831 		FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version));
832 }
833 static DEVICE_ATTR_RO(protocol_version);
834 
firmware_version_show(struct device * dev,struct device_attribute * attr,char * buf)835 static ssize_t firmware_version_show(struct device *dev,
836 				     struct device_attribute *attr, char *buf)
837 {
838 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
839 
840 	return sprintf(buf, "%lu.%lu.%lu\n",
841 		FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
842 		FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
843 		FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
844 }
845 static DEVICE_ATTR_RO(firmware_version);
846 
847 static struct attribute *versions_attrs[] = {
848 	&dev_attr_firmware_version.attr,
849 	&dev_attr_protocol_version.attr,
850 	NULL,
851 };
852 ATTRIBUTE_GROUPS(versions);
853 
scpi_free_channels(void * data)854 static void scpi_free_channels(void *data)
855 {
856 	struct scpi_drvinfo *info = data;
857 	int i;
858 
859 	for (i = 0; i < info->num_chans; i++)
860 		mbox_free_channel(info->channels[i].chan);
861 }
862 
scpi_remove(struct platform_device * pdev)863 static int scpi_remove(struct platform_device *pdev)
864 {
865 	int i;
866 	struct scpi_drvinfo *info = platform_get_drvdata(pdev);
867 
868 	scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
869 
870 	for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
871 		kfree(info->dvfs[i]->opps);
872 		kfree(info->dvfs[i]);
873 	}
874 
875 	return 0;
876 }
877 
878 #define MAX_SCPI_XFERS		10
scpi_alloc_xfer_list(struct device * dev,struct scpi_chan * ch)879 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
880 {
881 	int i;
882 	struct scpi_xfer *xfers;
883 
884 	xfers = devm_kcalloc(dev, MAX_SCPI_XFERS, sizeof(*xfers), GFP_KERNEL);
885 	if (!xfers)
886 		return -ENOMEM;
887 
888 	ch->xfers = xfers;
889 	for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
890 		init_completion(&xfers->done);
891 		list_add_tail(&xfers->node, &ch->xfers_list);
892 	}
893 
894 	return 0;
895 }
896 
897 static const struct of_device_id legacy_scpi_of_match[] = {
898 	{.compatible = "arm,scpi-pre-1.0"},
899 	{},
900 };
901 
902 static const struct of_device_id shmem_of_match[] __maybe_unused = {
903 	{ .compatible = "amlogic,meson-gxbb-scp-shmem", },
904 	{ .compatible = "amlogic,meson-axg-scp-shmem", },
905 	{ .compatible = "arm,juno-scp-shmem", },
906 	{ .compatible = "arm,scp-shmem", },
907 	{ }
908 };
909 
scpi_probe(struct platform_device * pdev)910 static int scpi_probe(struct platform_device *pdev)
911 {
912 	int count, idx, ret;
913 	struct resource res;
914 	struct device *dev = &pdev->dev;
915 	struct device_node *np = dev->of_node;
916 	struct scpi_drvinfo *scpi_drvinfo;
917 
918 	scpi_drvinfo = devm_kzalloc(dev, sizeof(*scpi_drvinfo), GFP_KERNEL);
919 	if (!scpi_drvinfo)
920 		return -ENOMEM;
921 
922 	if (of_match_device(legacy_scpi_of_match, &pdev->dev))
923 		scpi_drvinfo->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_drvinfo->channels =
932 		devm_kcalloc(dev, count, sizeof(struct scpi_chan), GFP_KERNEL);
933 	if (!scpi_drvinfo->channels)
934 		return -ENOMEM;
935 
936 	ret = devm_add_action(dev, scpi_free_channels, scpi_drvinfo);
937 	if (ret)
938 		return ret;
939 
940 	for (; scpi_drvinfo->num_chans < count; scpi_drvinfo->num_chans++) {
941 		resource_size_t size;
942 		int idx = scpi_drvinfo->num_chans;
943 		struct scpi_chan *pchan = scpi_drvinfo->channels + idx;
944 		struct mbox_client *cl = &pchan->cl;
945 		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
946 
947 		if (!of_match_node(shmem_of_match, shmem))
948 			return -ENXIO;
949 
950 		ret = of_address_to_resource(shmem, 0, &res);
951 		of_node_put(shmem);
952 		if (ret) {
953 			dev_err(dev, "failed to get SCPI payload mem resource\n");
954 			return ret;
955 		}
956 
957 		size = resource_size(&res);
958 		pchan->rx_payload = devm_ioremap(dev, res.start, size);
959 		if (!pchan->rx_payload) {
960 			dev_err(dev, "failed to ioremap SCPI payload\n");
961 			return -EADDRNOTAVAIL;
962 		}
963 		pchan->tx_payload = pchan->rx_payload + (size >> 1);
964 
965 		cl->dev = dev;
966 		cl->rx_callback = scpi_handle_remote_msg;
967 		cl->tx_prepare = scpi_tx_prepare;
968 		cl->tx_block = true;
969 		cl->tx_tout = 20;
970 		cl->knows_txdone = false; /* controller can't ack */
971 
972 		INIT_LIST_HEAD(&pchan->rx_pending);
973 		INIT_LIST_HEAD(&pchan->xfers_list);
974 		spin_lock_init(&pchan->rx_lock);
975 		mutex_init(&pchan->xfers_lock);
976 
977 		ret = scpi_alloc_xfer_list(dev, pchan);
978 		if (!ret) {
979 			pchan->chan = mbox_request_channel(cl, idx);
980 			if (!IS_ERR(pchan->chan))
981 				continue;
982 			ret = PTR_ERR(pchan->chan);
983 			if (ret != -EPROBE_DEFER)
984 				dev_err(dev, "failed to get channel%d err %d\n",
985 					idx, ret);
986 		}
987 		return ret;
988 	}
989 
990 	scpi_drvinfo->commands = scpi_std_commands;
991 
992 	platform_set_drvdata(pdev, scpi_drvinfo);
993 
994 	if (scpi_drvinfo->is_legacy) {
995 		/* Replace with legacy variants */
996 		scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
997 		scpi_drvinfo->commands = scpi_legacy_commands;
998 
999 		/* Fill priority bitmap */
1000 		for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
1001 			set_bit(legacy_hpriority_cmds[idx],
1002 				scpi_drvinfo->cmd_priority);
1003 	}
1004 
1005 	scpi_info = scpi_drvinfo;
1006 
1007 	ret = scpi_init_versions(scpi_drvinfo);
1008 	if (ret) {
1009 		dev_err(dev, "incorrect or no SCP firmware found\n");
1010 		scpi_info = NULL;
1011 		return ret;
1012 	}
1013 
1014 	if (scpi_drvinfo->is_legacy && !scpi_drvinfo->protocol_version &&
1015 	    !scpi_drvinfo->firmware_version)
1016 		dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
1017 	else
1018 		dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1019 			 FIELD_GET(PROTO_REV_MAJOR_MASK,
1020 				   scpi_drvinfo->protocol_version),
1021 			 FIELD_GET(PROTO_REV_MINOR_MASK,
1022 				   scpi_drvinfo->protocol_version),
1023 			 FIELD_GET(FW_REV_MAJOR_MASK,
1024 				   scpi_drvinfo->firmware_version),
1025 			 FIELD_GET(FW_REV_MINOR_MASK,
1026 				   scpi_drvinfo->firmware_version),
1027 			 FIELD_GET(FW_REV_PATCH_MASK,
1028 				   scpi_drvinfo->firmware_version));
1029 
1030 	scpi_drvinfo->scpi_ops = &scpi_ops;
1031 
1032 	ret = devm_of_platform_populate(dev);
1033 	if (ret)
1034 		scpi_info = NULL;
1035 
1036 	return ret;
1037 }
1038 
1039 static const struct of_device_id scpi_of_match[] = {
1040 	{.compatible = "arm,scpi"},
1041 	{.compatible = "arm,scpi-pre-1.0"},
1042 	{},
1043 };
1044 
1045 MODULE_DEVICE_TABLE(of, scpi_of_match);
1046 
1047 static struct platform_driver scpi_driver = {
1048 	.driver = {
1049 		.name = "scpi_protocol",
1050 		.of_match_table = scpi_of_match,
1051 		.dev_groups = versions_groups,
1052 	},
1053 	.probe = scpi_probe,
1054 	.remove = scpi_remove,
1055 };
1056 module_platform_driver(scpi_driver);
1057 
1058 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1059 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1060 MODULE_LICENSE("GPL v2");
1061