xref: /openbmc/linux/drivers/firmware/arm_scpi.c (revision e3b9f1e8)
1 /*
2  * System Control and Power Interface (SCPI) Message Protocol driver
3  *
4  * SCPI Message Protocol is used between the System Control Processor(SCP)
5  * and the Application Processors(AP). The Message Handling Unit(MHU)
6  * provides a mechanism for inter-processor communication between SCP's
7  * Cortex M3 and AP.
8  *
9  * SCP offers control and management of the core/cluster power states,
10  * various power domain DVFS including the core/cluster, certain system
11  * clocks configuration, thermal sensors and many others.
12  *
13  * Copyright (C) 2015 ARM Ltd.
14  *
15  * This program is free software; you can redistribute it and/or modify it
16  * under the terms and conditions of the GNU General Public License,
17  * version 2, as published by the Free Software Foundation.
18  *
19  * This program is distributed in the hope it will be useful, but WITHOUT
20  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
22  * more details.
23  *
24  * You should have received a copy of the GNU General Public License along
25  * with this program. If not, see <http://www.gnu.org/licenses/>.
26  */
27 
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29 
30 #include <linux/bitmap.h>
31 #include <linux/device.h>
32 #include <linux/err.h>
33 #include <linux/export.h>
34 #include <linux/io.h>
35 #include <linux/kernel.h>
36 #include <linux/list.h>
37 #include <linux/mailbox_client.h>
38 #include <linux/module.h>
39 #include <linux/of_address.h>
40 #include <linux/of_platform.h>
41 #include <linux/printk.h>
42 #include <linux/pm_opp.h>
43 #include <linux/scpi_protocol.h>
44 #include <linux/slab.h>
45 #include <linux/sort.h>
46 #include <linux/spinlock.h>
47 
48 #define CMD_ID_SHIFT		0
49 #define CMD_ID_MASK		0x7f
50 #define CMD_TOKEN_ID_SHIFT	8
51 #define CMD_TOKEN_ID_MASK	0xff
52 #define CMD_DATA_SIZE_SHIFT	16
53 #define CMD_DATA_SIZE_MASK	0x1ff
54 #define CMD_LEGACY_DATA_SIZE_SHIFT	20
55 #define CMD_LEGACY_DATA_SIZE_MASK	0x1ff
56 #define PACK_SCPI_CMD(cmd_id, tx_sz)			\
57 	((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |	\
58 	(((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
59 #define ADD_SCPI_TOKEN(cmd, token)			\
60 	((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
61 #define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)				\
62 	((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |			       \
63 	(((tx_sz) & CMD_LEGACY_DATA_SIZE_MASK) << CMD_LEGACY_DATA_SIZE_SHIFT))
64 
65 #define CMD_SIZE(cmd)	(((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
66 #define CMD_LEGACY_SIZE(cmd)	(((cmd) >> CMD_LEGACY_DATA_SIZE_SHIFT) & \
67 					CMD_LEGACY_DATA_SIZE_MASK)
68 #define CMD_UNIQ_MASK	(CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
69 #define CMD_XTRACT_UNIQ(cmd)	((cmd) & CMD_UNIQ_MASK)
70 
71 #define SCPI_SLOT		0
72 
73 #define MAX_DVFS_DOMAINS	8
74 #define MAX_DVFS_OPPS		16
75 #define DVFS_LATENCY(hdr)	(le32_to_cpu(hdr) >> 16)
76 #define DVFS_OPP_COUNT(hdr)	((le32_to_cpu(hdr) >> 8) & 0xff)
77 
78 #define PROTOCOL_REV_MINOR_BITS	16
79 #define PROTOCOL_REV_MINOR_MASK	((1U << PROTOCOL_REV_MINOR_BITS) - 1)
80 #define PROTOCOL_REV_MAJOR(x)	((x) >> PROTOCOL_REV_MINOR_BITS)
81 #define PROTOCOL_REV_MINOR(x)	((x) & PROTOCOL_REV_MINOR_MASK)
82 
83 #define FW_REV_MAJOR_BITS	24
84 #define FW_REV_MINOR_BITS	16
85 #define FW_REV_PATCH_MASK	((1U << FW_REV_MINOR_BITS) - 1)
86 #define FW_REV_MINOR_MASK	((1U << FW_REV_MAJOR_BITS) - 1)
87 #define FW_REV_MAJOR(x)		((x) >> FW_REV_MAJOR_BITS)
88 #define FW_REV_MINOR(x)		(((x) & FW_REV_MINOR_MASK) >> FW_REV_MINOR_BITS)
89 #define FW_REV_PATCH(x)		((x) & FW_REV_PATCH_MASK)
90 
91 #define MAX_RX_TIMEOUT		(msecs_to_jiffies(30))
92 
93 enum scpi_error_codes {
94 	SCPI_SUCCESS = 0, /* Success */
95 	SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
96 	SCPI_ERR_ALIGN = 2, /* Invalid alignment */
97 	SCPI_ERR_SIZE = 3, /* Invalid size */
98 	SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
99 	SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
100 	SCPI_ERR_RANGE = 6, /* Value out of range */
101 	SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
102 	SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
103 	SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
104 	SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
105 	SCPI_ERR_DEVICE = 11, /* Device error */
106 	SCPI_ERR_BUSY = 12, /* Device busy */
107 	SCPI_ERR_MAX
108 };
109 
110 /* SCPI Standard commands */
111 enum scpi_std_cmd {
112 	SCPI_CMD_INVALID		= 0x00,
113 	SCPI_CMD_SCPI_READY		= 0x01,
114 	SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
115 	SCPI_CMD_SET_CSS_PWR_STATE	= 0x03,
116 	SCPI_CMD_GET_CSS_PWR_STATE	= 0x04,
117 	SCPI_CMD_SET_SYS_PWR_STATE	= 0x05,
118 	SCPI_CMD_SET_CPU_TIMER		= 0x06,
119 	SCPI_CMD_CANCEL_CPU_TIMER	= 0x07,
120 	SCPI_CMD_DVFS_CAPABILITIES	= 0x08,
121 	SCPI_CMD_GET_DVFS_INFO		= 0x09,
122 	SCPI_CMD_SET_DVFS		= 0x0a,
123 	SCPI_CMD_GET_DVFS		= 0x0b,
124 	SCPI_CMD_GET_DVFS_STAT		= 0x0c,
125 	SCPI_CMD_CLOCK_CAPABILITIES	= 0x0d,
126 	SCPI_CMD_GET_CLOCK_INFO		= 0x0e,
127 	SCPI_CMD_SET_CLOCK_VALUE	= 0x0f,
128 	SCPI_CMD_GET_CLOCK_VALUE	= 0x10,
129 	SCPI_CMD_PSU_CAPABILITIES	= 0x11,
130 	SCPI_CMD_GET_PSU_INFO		= 0x12,
131 	SCPI_CMD_SET_PSU		= 0x13,
132 	SCPI_CMD_GET_PSU		= 0x14,
133 	SCPI_CMD_SENSOR_CAPABILITIES	= 0x15,
134 	SCPI_CMD_SENSOR_INFO		= 0x16,
135 	SCPI_CMD_SENSOR_VALUE		= 0x17,
136 	SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x18,
137 	SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x19,
138 	SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1a,
139 	SCPI_CMD_SET_DEVICE_PWR_STATE	= 0x1b,
140 	SCPI_CMD_GET_DEVICE_PWR_STATE	= 0x1c,
141 	SCPI_CMD_COUNT
142 };
143 
144 /* SCPI Legacy Commands */
145 enum legacy_scpi_std_cmd {
146 	LEGACY_SCPI_CMD_INVALID			= 0x00,
147 	LEGACY_SCPI_CMD_SCPI_READY		= 0x01,
148 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES	= 0x02,
149 	LEGACY_SCPI_CMD_EVENT			= 0x03,
150 	LEGACY_SCPI_CMD_SET_CSS_PWR_STATE	= 0x04,
151 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE	= 0x05,
152 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT	= 0x06,
153 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT	= 0x07,
154 	LEGACY_SCPI_CMD_SYS_PWR_STATE		= 0x08,
155 	LEGACY_SCPI_CMD_L2_READY		= 0x09,
156 	LEGACY_SCPI_CMD_SET_AP_TIMER		= 0x0a,
157 	LEGACY_SCPI_CMD_CANCEL_AP_TIME		= 0x0b,
158 	LEGACY_SCPI_CMD_DVFS_CAPABILITIES	= 0x0c,
159 	LEGACY_SCPI_CMD_GET_DVFS_INFO		= 0x0d,
160 	LEGACY_SCPI_CMD_SET_DVFS		= 0x0e,
161 	LEGACY_SCPI_CMD_GET_DVFS		= 0x0f,
162 	LEGACY_SCPI_CMD_GET_DVFS_STAT		= 0x10,
163 	LEGACY_SCPI_CMD_SET_RTC			= 0x11,
164 	LEGACY_SCPI_CMD_GET_RTC			= 0x12,
165 	LEGACY_SCPI_CMD_CLOCK_CAPABILITIES	= 0x13,
166 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX		= 0x14,
167 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE		= 0x15,
168 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE		= 0x16,
169 	LEGACY_SCPI_CMD_PSU_CAPABILITIES	= 0x17,
170 	LEGACY_SCPI_CMD_SET_PSU			= 0x18,
171 	LEGACY_SCPI_CMD_GET_PSU			= 0x19,
172 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES	= 0x1a,
173 	LEGACY_SCPI_CMD_SENSOR_INFO		= 0x1b,
174 	LEGACY_SCPI_CMD_SENSOR_VALUE		= 0x1c,
175 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC	= 0x1d,
176 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS	= 0x1e,
177 	LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE	= 0x1f,
178 	LEGACY_SCPI_CMD_COUNT
179 };
180 
181 /* List all commands that are required to go through the high priority link */
182 static int legacy_hpriority_cmds[] = {
183 	LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
184 	LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
185 	LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
186 	LEGACY_SCPI_CMD_SET_DVFS,
187 	LEGACY_SCPI_CMD_GET_DVFS,
188 	LEGACY_SCPI_CMD_SET_RTC,
189 	LEGACY_SCPI_CMD_GET_RTC,
190 	LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
191 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
192 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
193 	LEGACY_SCPI_CMD_SET_PSU,
194 	LEGACY_SCPI_CMD_GET_PSU,
195 	LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
196 	LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
197 };
198 
199 /* List all commands used by this driver, used as indexes */
200 enum scpi_drv_cmds {
201 	CMD_SCPI_CAPABILITIES = 0,
202 	CMD_GET_CLOCK_INFO,
203 	CMD_GET_CLOCK_VALUE,
204 	CMD_SET_CLOCK_VALUE,
205 	CMD_GET_DVFS,
206 	CMD_SET_DVFS,
207 	CMD_GET_DVFS_INFO,
208 	CMD_SENSOR_CAPABILITIES,
209 	CMD_SENSOR_INFO,
210 	CMD_SENSOR_VALUE,
211 	CMD_SET_DEVICE_PWR_STATE,
212 	CMD_GET_DEVICE_PWR_STATE,
213 	CMD_MAX_COUNT,
214 };
215 
216 static int scpi_std_commands[CMD_MAX_COUNT] = {
217 	SCPI_CMD_SCPI_CAPABILITIES,
218 	SCPI_CMD_GET_CLOCK_INFO,
219 	SCPI_CMD_GET_CLOCK_VALUE,
220 	SCPI_CMD_SET_CLOCK_VALUE,
221 	SCPI_CMD_GET_DVFS,
222 	SCPI_CMD_SET_DVFS,
223 	SCPI_CMD_GET_DVFS_INFO,
224 	SCPI_CMD_SENSOR_CAPABILITIES,
225 	SCPI_CMD_SENSOR_INFO,
226 	SCPI_CMD_SENSOR_VALUE,
227 	SCPI_CMD_SET_DEVICE_PWR_STATE,
228 	SCPI_CMD_GET_DEVICE_PWR_STATE,
229 };
230 
231 static int scpi_legacy_commands[CMD_MAX_COUNT] = {
232 	LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
233 	-1, /* GET_CLOCK_INFO */
234 	LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
235 	LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
236 	LEGACY_SCPI_CMD_GET_DVFS,
237 	LEGACY_SCPI_CMD_SET_DVFS,
238 	LEGACY_SCPI_CMD_GET_DVFS_INFO,
239 	LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
240 	LEGACY_SCPI_CMD_SENSOR_INFO,
241 	LEGACY_SCPI_CMD_SENSOR_VALUE,
242 	-1, /* SET_DEVICE_PWR_STATE */
243 	-1, /* GET_DEVICE_PWR_STATE */
244 };
245 
246 struct scpi_xfer {
247 	u32 slot; /* has to be first element */
248 	u32 cmd;
249 	u32 status;
250 	const void *tx_buf;
251 	void *rx_buf;
252 	unsigned int tx_len;
253 	unsigned int rx_len;
254 	struct list_head node;
255 	struct completion done;
256 };
257 
258 struct scpi_chan {
259 	struct mbox_client cl;
260 	struct mbox_chan *chan;
261 	void __iomem *tx_payload;
262 	void __iomem *rx_payload;
263 	struct list_head rx_pending;
264 	struct list_head xfers_list;
265 	struct scpi_xfer *xfers;
266 	spinlock_t rx_lock; /* locking for the rx pending list */
267 	struct mutex xfers_lock;
268 	u8 token;
269 };
270 
271 struct scpi_drvinfo {
272 	u32 protocol_version;
273 	u32 firmware_version;
274 	bool is_legacy;
275 	int num_chans;
276 	int *commands;
277 	DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
278 	atomic_t next_chan;
279 	struct scpi_ops *scpi_ops;
280 	struct scpi_chan *channels;
281 	struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
282 };
283 
284 /*
285  * The SCP firmware only executes in little-endian mode, so any buffers
286  * shared through SCPI should have their contents converted to little-endian
287  */
288 struct scpi_shared_mem {
289 	__le32 command;
290 	__le32 status;
291 	u8 payload[0];
292 } __packed;
293 
294 struct legacy_scpi_shared_mem {
295 	__le32 status;
296 	u8 payload[0];
297 } __packed;
298 
299 struct scp_capabilities {
300 	__le32 protocol_version;
301 	__le32 event_version;
302 	__le32 platform_version;
303 	__le32 commands[4];
304 } __packed;
305 
306 struct clk_get_info {
307 	__le16 id;
308 	__le16 flags;
309 	__le32 min_rate;
310 	__le32 max_rate;
311 	u8 name[20];
312 } __packed;
313 
314 struct clk_get_value {
315 	__le32 rate;
316 } __packed;
317 
318 struct clk_set_value {
319 	__le16 id;
320 	__le16 reserved;
321 	__le32 rate;
322 } __packed;
323 
324 struct legacy_clk_set_value {
325 	__le32 rate;
326 	__le16 id;
327 	__le16 reserved;
328 } __packed;
329 
330 struct dvfs_info {
331 	__le32 header;
332 	struct {
333 		__le32 freq;
334 		__le32 m_volt;
335 	} opps[MAX_DVFS_OPPS];
336 } __packed;
337 
338 struct dvfs_set {
339 	u8 domain;
340 	u8 index;
341 } __packed;
342 
343 struct sensor_capabilities {
344 	__le16 sensors;
345 } __packed;
346 
347 struct _scpi_sensor_info {
348 	__le16 sensor_id;
349 	u8 class;
350 	u8 trigger_type;
351 	char name[20];
352 };
353 
354 struct sensor_value {
355 	__le32 lo_val;
356 	__le32 hi_val;
357 } __packed;
358 
359 struct dev_pstate_set {
360 	__le16 dev_id;
361 	u8 pstate;
362 } __packed;
363 
364 static struct scpi_drvinfo *scpi_info;
365 
366 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
367 	/* better than switch case as long as return value is continuous */
368 	0, /* SCPI_SUCCESS */
369 	-EINVAL, /* SCPI_ERR_PARAM */
370 	-ENOEXEC, /* SCPI_ERR_ALIGN */
371 	-EMSGSIZE, /* SCPI_ERR_SIZE */
372 	-EINVAL, /* SCPI_ERR_HANDLER */
373 	-EACCES, /* SCPI_ERR_ACCESS */
374 	-ERANGE, /* SCPI_ERR_RANGE */
375 	-ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
376 	-ENOMEM, /* SCPI_ERR_NOMEM */
377 	-EINVAL, /* SCPI_ERR_PWRSTATE */
378 	-EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
379 	-EIO, /* SCPI_ERR_DEVICE */
380 	-EBUSY, /* SCPI_ERR_BUSY */
381 };
382 
383 static inline int scpi_to_linux_errno(int errno)
384 {
385 	if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
386 		return scpi_linux_errmap[errno];
387 	return -EIO;
388 }
389 
390 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
391 {
392 	unsigned long flags;
393 	struct scpi_xfer *t, *match = NULL;
394 
395 	spin_lock_irqsave(&ch->rx_lock, flags);
396 	if (list_empty(&ch->rx_pending)) {
397 		spin_unlock_irqrestore(&ch->rx_lock, flags);
398 		return;
399 	}
400 
401 	/* Command type is not replied by the SCP Firmware in legacy Mode
402 	 * We should consider that command is the head of pending RX commands
403 	 * if the list is not empty. In TX only mode, the list would be empty.
404 	 */
405 	if (scpi_info->is_legacy) {
406 		match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
407 					 node);
408 		list_del(&match->node);
409 	} else {
410 		list_for_each_entry(t, &ch->rx_pending, node)
411 			if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
412 				list_del(&t->node);
413 				match = t;
414 				break;
415 			}
416 	}
417 	/* check if wait_for_completion is in progress or timed-out */
418 	if (match && !completion_done(&match->done)) {
419 		unsigned int len;
420 
421 		if (scpi_info->is_legacy) {
422 			struct legacy_scpi_shared_mem *mem = ch->rx_payload;
423 
424 			/* RX Length is not replied by the legacy Firmware */
425 			len = match->rx_len;
426 
427 			match->status = le32_to_cpu(mem->status);
428 			memcpy_fromio(match->rx_buf, mem->payload, len);
429 		} else {
430 			struct scpi_shared_mem *mem = ch->rx_payload;
431 
432 			len = min(match->rx_len, CMD_SIZE(cmd));
433 
434 			match->status = le32_to_cpu(mem->status);
435 			memcpy_fromio(match->rx_buf, mem->payload, len);
436 		}
437 
438 		if (match->rx_len > len)
439 			memset(match->rx_buf + len, 0, match->rx_len - len);
440 		complete(&match->done);
441 	}
442 	spin_unlock_irqrestore(&ch->rx_lock, flags);
443 }
444 
445 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
446 {
447 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
448 	struct scpi_shared_mem *mem = ch->rx_payload;
449 	u32 cmd = 0;
450 
451 	if (!scpi_info->is_legacy)
452 		cmd = le32_to_cpu(mem->command);
453 
454 	scpi_process_cmd(ch, cmd);
455 }
456 
457 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
458 {
459 	unsigned long flags;
460 	struct scpi_xfer *t = msg;
461 	struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
462 	struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
463 
464 	if (t->tx_buf) {
465 		if (scpi_info->is_legacy)
466 			memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
467 		else
468 			memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
469 	}
470 
471 	if (t->rx_buf) {
472 		if (!(++ch->token))
473 			++ch->token;
474 		ADD_SCPI_TOKEN(t->cmd, ch->token);
475 		spin_lock_irqsave(&ch->rx_lock, flags);
476 		list_add_tail(&t->node, &ch->rx_pending);
477 		spin_unlock_irqrestore(&ch->rx_lock, flags);
478 	}
479 
480 	if (!scpi_info->is_legacy)
481 		mem->command = cpu_to_le32(t->cmd);
482 }
483 
484 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
485 {
486 	struct scpi_xfer *t;
487 
488 	mutex_lock(&ch->xfers_lock);
489 	if (list_empty(&ch->xfers_list)) {
490 		mutex_unlock(&ch->xfers_lock);
491 		return NULL;
492 	}
493 	t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
494 	list_del(&t->node);
495 	mutex_unlock(&ch->xfers_lock);
496 	return t;
497 }
498 
499 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
500 {
501 	mutex_lock(&ch->xfers_lock);
502 	list_add_tail(&t->node, &ch->xfers_list);
503 	mutex_unlock(&ch->xfers_lock);
504 }
505 
506 static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
507 			     void *rx_buf, unsigned int rx_len)
508 {
509 	int ret;
510 	u8 chan;
511 	u8 cmd;
512 	struct scpi_xfer *msg;
513 	struct scpi_chan *scpi_chan;
514 
515 	if (scpi_info->commands[idx] < 0)
516 		return -EOPNOTSUPP;
517 
518 	cmd = scpi_info->commands[idx];
519 
520 	if (scpi_info->is_legacy)
521 		chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
522 	else
523 		chan = atomic_inc_return(&scpi_info->next_chan) %
524 			scpi_info->num_chans;
525 	scpi_chan = scpi_info->channels + chan;
526 
527 	msg = get_scpi_xfer(scpi_chan);
528 	if (!msg)
529 		return -ENOMEM;
530 
531 	if (scpi_info->is_legacy) {
532 		msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
533 		msg->slot = msg->cmd;
534 	} else {
535 		msg->slot = BIT(SCPI_SLOT);
536 		msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
537 	}
538 	msg->tx_buf = tx_buf;
539 	msg->tx_len = tx_len;
540 	msg->rx_buf = rx_buf;
541 	msg->rx_len = rx_len;
542 	reinit_completion(&msg->done);
543 
544 	ret = mbox_send_message(scpi_chan->chan, msg);
545 	if (ret < 0 || !rx_buf)
546 		goto out;
547 
548 	if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
549 		ret = -ETIMEDOUT;
550 	else
551 		/* first status word */
552 		ret = msg->status;
553 out:
554 	if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
555 		scpi_process_cmd(scpi_chan, msg->cmd);
556 
557 	put_scpi_xfer(msg, scpi_chan);
558 	/* SCPI error codes > 0, translate them to Linux scale*/
559 	return ret > 0 ? scpi_to_linux_errno(ret) : ret;
560 }
561 
562 static u32 scpi_get_version(void)
563 {
564 	return scpi_info->protocol_version;
565 }
566 
567 static int
568 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
569 {
570 	int ret;
571 	struct clk_get_info clk;
572 	__le16 le_clk_id = cpu_to_le16(clk_id);
573 
574 	ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
575 				sizeof(le_clk_id), &clk, sizeof(clk));
576 	if (!ret) {
577 		*min = le32_to_cpu(clk.min_rate);
578 		*max = le32_to_cpu(clk.max_rate);
579 	}
580 	return ret;
581 }
582 
583 static unsigned long scpi_clk_get_val(u16 clk_id)
584 {
585 	int ret;
586 	struct clk_get_value clk;
587 	__le16 le_clk_id = cpu_to_le16(clk_id);
588 
589 	ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
590 				sizeof(le_clk_id), &clk, sizeof(clk));
591 
592 	return ret ? ret : le32_to_cpu(clk.rate);
593 }
594 
595 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
596 {
597 	int stat;
598 	struct clk_set_value clk = {
599 		.id = cpu_to_le16(clk_id),
600 		.rate = cpu_to_le32(rate)
601 	};
602 
603 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
604 				 &stat, sizeof(stat));
605 }
606 
607 static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
608 {
609 	int stat;
610 	struct legacy_clk_set_value clk = {
611 		.id = cpu_to_le16(clk_id),
612 		.rate = cpu_to_le32(rate)
613 	};
614 
615 	return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
616 				 &stat, sizeof(stat));
617 }
618 
619 static int scpi_dvfs_get_idx(u8 domain)
620 {
621 	int ret;
622 	u8 dvfs_idx;
623 
624 	ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
625 				&dvfs_idx, sizeof(dvfs_idx));
626 
627 	return ret ? ret : dvfs_idx;
628 }
629 
630 static int scpi_dvfs_set_idx(u8 domain, u8 index)
631 {
632 	int stat;
633 	struct dvfs_set dvfs = {domain, index};
634 
635 	return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
636 				 &stat, sizeof(stat));
637 }
638 
639 static int opp_cmp_func(const void *opp1, const void *opp2)
640 {
641 	const struct scpi_opp *t1 = opp1, *t2 = opp2;
642 
643 	return t1->freq - t2->freq;
644 }
645 
646 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
647 {
648 	struct scpi_dvfs_info *info;
649 	struct scpi_opp *opp;
650 	struct dvfs_info buf;
651 	int ret, i;
652 
653 	if (domain >= MAX_DVFS_DOMAINS)
654 		return ERR_PTR(-EINVAL);
655 
656 	if (scpi_info->dvfs[domain])	/* data already populated */
657 		return scpi_info->dvfs[domain];
658 
659 	ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
660 				&buf, sizeof(buf));
661 	if (ret)
662 		return ERR_PTR(ret);
663 
664 	info = kmalloc(sizeof(*info), GFP_KERNEL);
665 	if (!info)
666 		return ERR_PTR(-ENOMEM);
667 
668 	info->count = DVFS_OPP_COUNT(buf.header);
669 	info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
670 
671 	info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
672 	if (!info->opps) {
673 		kfree(info);
674 		return ERR_PTR(-ENOMEM);
675 	}
676 
677 	for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
678 		opp->freq = le32_to_cpu(buf.opps[i].freq);
679 		opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
680 	}
681 
682 	sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
683 
684 	scpi_info->dvfs[domain] = info;
685 	return info;
686 }
687 
688 static int scpi_dev_domain_id(struct device *dev)
689 {
690 	struct of_phandle_args clkspec;
691 
692 	if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
693 				       0, &clkspec))
694 		return -EINVAL;
695 
696 	return clkspec.args[0];
697 }
698 
699 static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
700 {
701 	int domain = scpi_dev_domain_id(dev);
702 
703 	if (domain < 0)
704 		return ERR_PTR(domain);
705 
706 	return scpi_dvfs_get_info(domain);
707 }
708 
709 static int scpi_dvfs_get_transition_latency(struct device *dev)
710 {
711 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
712 
713 	if (IS_ERR(info))
714 		return PTR_ERR(info);
715 
716 	if (!info->latency)
717 		return 0;
718 
719 	return info->latency;
720 }
721 
722 static int scpi_dvfs_add_opps_to_device(struct device *dev)
723 {
724 	int idx, ret;
725 	struct scpi_opp *opp;
726 	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
727 
728 	if (IS_ERR(info))
729 		return PTR_ERR(info);
730 
731 	if (!info->opps)
732 		return -EIO;
733 
734 	for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
735 		ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
736 		if (ret) {
737 			dev_warn(dev, "failed to add opp %uHz %umV\n",
738 				 opp->freq, opp->m_volt);
739 			while (idx-- > 0)
740 				dev_pm_opp_remove(dev, (--opp)->freq);
741 			return ret;
742 		}
743 	}
744 	return 0;
745 }
746 
747 static int scpi_sensor_get_capability(u16 *sensors)
748 {
749 	struct sensor_capabilities cap_buf;
750 	int ret;
751 
752 	ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
753 				sizeof(cap_buf));
754 	if (!ret)
755 		*sensors = le16_to_cpu(cap_buf.sensors);
756 
757 	return ret;
758 }
759 
760 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
761 {
762 	__le16 id = cpu_to_le16(sensor_id);
763 	struct _scpi_sensor_info _info;
764 	int ret;
765 
766 	ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
767 				&_info, sizeof(_info));
768 	if (!ret) {
769 		memcpy(info, &_info, sizeof(*info));
770 		info->sensor_id = le16_to_cpu(_info.sensor_id);
771 	}
772 
773 	return ret;
774 }
775 
776 static int scpi_sensor_get_value(u16 sensor, u64 *val)
777 {
778 	__le16 id = cpu_to_le16(sensor);
779 	struct sensor_value buf;
780 	int ret;
781 
782 	ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
783 				&buf, sizeof(buf));
784 	if (ret)
785 		return ret;
786 
787 	if (scpi_info->is_legacy)
788 		/* only 32-bits supported, hi_val can be junk */
789 		*val = le32_to_cpu(buf.lo_val);
790 	else
791 		*val = (u64)le32_to_cpu(buf.hi_val) << 32 |
792 			le32_to_cpu(buf.lo_val);
793 
794 	return 0;
795 }
796 
797 static int scpi_device_get_power_state(u16 dev_id)
798 {
799 	int ret;
800 	u8 pstate;
801 	__le16 id = cpu_to_le16(dev_id);
802 
803 	ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
804 				sizeof(id), &pstate, sizeof(pstate));
805 	return ret ? ret : pstate;
806 }
807 
808 static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
809 {
810 	int stat;
811 	struct dev_pstate_set dev_set = {
812 		.dev_id = cpu_to_le16(dev_id),
813 		.pstate = pstate,
814 	};
815 
816 	return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
817 				 sizeof(dev_set), &stat, sizeof(stat));
818 }
819 
820 static struct scpi_ops scpi_ops = {
821 	.get_version = scpi_get_version,
822 	.clk_get_range = scpi_clk_get_range,
823 	.clk_get_val = scpi_clk_get_val,
824 	.clk_set_val = scpi_clk_set_val,
825 	.dvfs_get_idx = scpi_dvfs_get_idx,
826 	.dvfs_set_idx = scpi_dvfs_set_idx,
827 	.dvfs_get_info = scpi_dvfs_get_info,
828 	.device_domain_id = scpi_dev_domain_id,
829 	.get_transition_latency = scpi_dvfs_get_transition_latency,
830 	.add_opps_to_device = scpi_dvfs_add_opps_to_device,
831 	.sensor_get_capability = scpi_sensor_get_capability,
832 	.sensor_get_info = scpi_sensor_get_info,
833 	.sensor_get_value = scpi_sensor_get_value,
834 	.device_get_power_state = scpi_device_get_power_state,
835 	.device_set_power_state = scpi_device_set_power_state,
836 };
837 
838 struct scpi_ops *get_scpi_ops(void)
839 {
840 	return scpi_info ? scpi_info->scpi_ops : NULL;
841 }
842 EXPORT_SYMBOL_GPL(get_scpi_ops);
843 
844 static int scpi_init_versions(struct scpi_drvinfo *info)
845 {
846 	int ret;
847 	struct scp_capabilities caps;
848 
849 	ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
850 				&caps, sizeof(caps));
851 	if (!ret) {
852 		info->protocol_version = le32_to_cpu(caps.protocol_version);
853 		info->firmware_version = le32_to_cpu(caps.platform_version);
854 	}
855 	/* Ignore error if not implemented */
856 	if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
857 		return 0;
858 
859 	return ret;
860 }
861 
862 static ssize_t protocol_version_show(struct device *dev,
863 				     struct device_attribute *attr, char *buf)
864 {
865 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
866 
867 	return sprintf(buf, "%d.%d\n",
868 		       PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
869 		       PROTOCOL_REV_MINOR(scpi_info->protocol_version));
870 }
871 static DEVICE_ATTR_RO(protocol_version);
872 
873 static ssize_t firmware_version_show(struct device *dev,
874 				     struct device_attribute *attr, char *buf)
875 {
876 	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
877 
878 	return sprintf(buf, "%d.%d.%d\n",
879 		       FW_REV_MAJOR(scpi_info->firmware_version),
880 		       FW_REV_MINOR(scpi_info->firmware_version),
881 		       FW_REV_PATCH(scpi_info->firmware_version));
882 }
883 static DEVICE_ATTR_RO(firmware_version);
884 
885 static struct attribute *versions_attrs[] = {
886 	&dev_attr_firmware_version.attr,
887 	&dev_attr_protocol_version.attr,
888 	NULL,
889 };
890 ATTRIBUTE_GROUPS(versions);
891 
892 static void
893 scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
894 {
895 	int i;
896 
897 	for (i = 0; i < count && pchan->chan; i++, pchan++) {
898 		mbox_free_channel(pchan->chan);
899 		devm_kfree(dev, pchan->xfers);
900 		devm_iounmap(dev, pchan->rx_payload);
901 	}
902 }
903 
904 static int scpi_remove(struct platform_device *pdev)
905 {
906 	int i;
907 	struct device *dev = &pdev->dev;
908 	struct scpi_drvinfo *info = platform_get_drvdata(pdev);
909 
910 	scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
911 
912 	of_platform_depopulate(dev);
913 	sysfs_remove_groups(&dev->kobj, versions_groups);
914 	scpi_free_channels(dev, info->channels, info->num_chans);
915 	platform_set_drvdata(pdev, NULL);
916 
917 	for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
918 		kfree(info->dvfs[i]->opps);
919 		kfree(info->dvfs[i]);
920 	}
921 	devm_kfree(dev, info->channels);
922 	devm_kfree(dev, info);
923 
924 	return 0;
925 }
926 
927 #define MAX_SCPI_XFERS		10
928 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
929 {
930 	int i;
931 	struct scpi_xfer *xfers;
932 
933 	xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
934 	if (!xfers)
935 		return -ENOMEM;
936 
937 	ch->xfers = xfers;
938 	for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
939 		init_completion(&xfers->done);
940 		list_add_tail(&xfers->node, &ch->xfers_list);
941 	}
942 
943 	return 0;
944 }
945 
946 static const struct of_device_id legacy_scpi_of_match[] = {
947 	{.compatible = "arm,scpi-pre-1.0"},
948 	{},
949 };
950 
951 static int scpi_probe(struct platform_device *pdev)
952 {
953 	int count, idx, ret;
954 	struct resource res;
955 	struct scpi_chan *scpi_chan;
956 	struct device *dev = &pdev->dev;
957 	struct device_node *np = dev->of_node;
958 
959 	scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
960 	if (!scpi_info)
961 		return -ENOMEM;
962 
963 	if (of_match_device(legacy_scpi_of_match, &pdev->dev))
964 		scpi_info->is_legacy = true;
965 
966 	count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
967 	if (count < 0) {
968 		dev_err(dev, "no mboxes property in '%pOF'\n", np);
969 		return -ENODEV;
970 	}
971 
972 	scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
973 	if (!scpi_chan)
974 		return -ENOMEM;
975 
976 	for (idx = 0; idx < count; idx++) {
977 		resource_size_t size;
978 		struct scpi_chan *pchan = scpi_chan + idx;
979 		struct mbox_client *cl = &pchan->cl;
980 		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
981 
982 		ret = of_address_to_resource(shmem, 0, &res);
983 		of_node_put(shmem);
984 		if (ret) {
985 			dev_err(dev, "failed to get SCPI payload mem resource\n");
986 			goto err;
987 		}
988 
989 		size = resource_size(&res);
990 		pchan->rx_payload = devm_ioremap(dev, res.start, size);
991 		if (!pchan->rx_payload) {
992 			dev_err(dev, "failed to ioremap SCPI payload\n");
993 			ret = -EADDRNOTAVAIL;
994 			goto err;
995 		}
996 		pchan->tx_payload = pchan->rx_payload + (size >> 1);
997 
998 		cl->dev = dev;
999 		cl->rx_callback = scpi_handle_remote_msg;
1000 		cl->tx_prepare = scpi_tx_prepare;
1001 		cl->tx_block = true;
1002 		cl->tx_tout = 20;
1003 		cl->knows_txdone = false; /* controller can't ack */
1004 
1005 		INIT_LIST_HEAD(&pchan->rx_pending);
1006 		INIT_LIST_HEAD(&pchan->xfers_list);
1007 		spin_lock_init(&pchan->rx_lock);
1008 		mutex_init(&pchan->xfers_lock);
1009 
1010 		ret = scpi_alloc_xfer_list(dev, pchan);
1011 		if (!ret) {
1012 			pchan->chan = mbox_request_channel(cl, idx);
1013 			if (!IS_ERR(pchan->chan))
1014 				continue;
1015 			ret = PTR_ERR(pchan->chan);
1016 			if (ret != -EPROBE_DEFER)
1017 				dev_err(dev, "failed to get channel%d err %d\n",
1018 					idx, ret);
1019 		}
1020 err:
1021 		scpi_free_channels(dev, scpi_chan, idx);
1022 		scpi_info = NULL;
1023 		return ret;
1024 	}
1025 
1026 	scpi_info->channels = scpi_chan;
1027 	scpi_info->num_chans = count;
1028 	scpi_info->commands = scpi_std_commands;
1029 
1030 	platform_set_drvdata(pdev, scpi_info);
1031 
1032 	if (scpi_info->is_legacy) {
1033 		/* Replace with legacy variants */
1034 		scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
1035 		scpi_info->commands = scpi_legacy_commands;
1036 
1037 		/* Fill priority bitmap */
1038 		for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
1039 			set_bit(legacy_hpriority_cmds[idx],
1040 				scpi_info->cmd_priority);
1041 	}
1042 
1043 	ret = scpi_init_versions(scpi_info);
1044 	if (ret) {
1045 		dev_err(dev, "incorrect or no SCP firmware found\n");
1046 		scpi_remove(pdev);
1047 		return ret;
1048 	}
1049 
1050 	_dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
1051 		  PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
1052 		  PROTOCOL_REV_MINOR(scpi_info->protocol_version),
1053 		  FW_REV_MAJOR(scpi_info->firmware_version),
1054 		  FW_REV_MINOR(scpi_info->firmware_version),
1055 		  FW_REV_PATCH(scpi_info->firmware_version));
1056 	scpi_info->scpi_ops = &scpi_ops;
1057 
1058 	ret = sysfs_create_groups(&dev->kobj, versions_groups);
1059 	if (ret)
1060 		dev_err(dev, "unable to create sysfs version group\n");
1061 
1062 	return of_platform_populate(dev->of_node, NULL, NULL, dev);
1063 }
1064 
1065 static const struct of_device_id scpi_of_match[] = {
1066 	{.compatible = "arm,scpi"},
1067 	{.compatible = "arm,scpi-pre-1.0"},
1068 	{},
1069 };
1070 
1071 MODULE_DEVICE_TABLE(of, scpi_of_match);
1072 
1073 static struct platform_driver scpi_driver = {
1074 	.driver = {
1075 		.name = "scpi_protocol",
1076 		.of_match_table = scpi_of_match,
1077 	},
1078 	.probe = scpi_probe,
1079 	.remove = scpi_remove,
1080 };
1081 module_platform_driver(scpi_driver);
1082 
1083 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1084 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1085 MODULE_LICENSE("GPL v2");
1086