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
67enum 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 */
85enum 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 */
119enum 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 */
156static 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 */
174enum 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
190static 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
205static 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
220struct 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
232struct 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
245struct 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 */
262struct scpi_shared_mem {
263	__le32 command;
264	__le32 status;
265	u8 payload[];
266} __packed;
267
268struct legacy_scpi_shared_mem {
269	__le32 status;
270	u8 payload[];
271} __packed;
272
273struct scp_capabilities {
274	__le32 protocol_version;
275	__le32 event_version;
276	__le32 platform_version;
277	__le32 commands[4];
278} __packed;
279
280struct clk_get_info {
281	__le16 id;
282	__le16 flags;
283	__le32 min_rate;
284	__le32 max_rate;
285	u8 name[20];
286} __packed;
287
288struct clk_set_value {
289	__le16 id;
290	__le16 reserved;
291	__le32 rate;
292} __packed;
293
294struct legacy_clk_set_value {
295	__le32 rate;
296	__le16 id;
297	__le16 reserved;
298} __packed;
299
300struct 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
310struct dvfs_set {
311	u8 domain;
312	u8 index;
313} __packed;
314
315struct _scpi_sensor_info {
316	__le16 sensor_id;
317	u8 class;
318	u8 trigger_type;
319	char name[20];
320};
321
322struct dev_pstate_set {
323	__le16 dev_id;
324	u8 pstate;
325} __packed;
326
327static struct scpi_drvinfo *scpi_info;
328
329static 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
346static 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
353static 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
409static 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
421static 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
448static 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
463static 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
470static 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;
517out:
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
526static u32 scpi_get_version(void)
527{
528	return scpi_info->protocol_version;
529}
530
531static int
532scpi_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
547static 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
561static 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
573static 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
585static 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
596static 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
605static 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
612static 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
654static 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
665static 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
675static 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
685static 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
710static 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
723static 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
739static 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
759static 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
770static 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
782static 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
800struct scpi_ops *get_scpi_ops(void)
801{
802	return scpi_info ? scpi_info->scpi_ops : NULL;
803}
804EXPORT_SYMBOL_GPL(get_scpi_ops);
805
806static 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
824static 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}
833static DEVICE_ATTR_RO(protocol_version);
834
835static 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}
845static DEVICE_ATTR_RO(firmware_version);
846
847static struct attribute *versions_attrs[] = {
848	&dev_attr_firmware_version.attr,
849	&dev_attr_protocol_version.attr,
850	NULL,
851};
852ATTRIBUTE_GROUPS(versions);
853
854static 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
863static 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
879static 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
897static const struct of_device_id legacy_scpi_of_match[] = {
898	{.compatible = "arm,scpi-pre-1.0"},
899	{},
900};
901
902static 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
910static 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
1039static const struct of_device_id scpi_of_match[] = {
1040	{.compatible = "arm,scpi"},
1041	{.compatible = "arm,scpi-pre-1.0"},
1042	{},
1043};
1044
1045MODULE_DEVICE_TABLE(of, scpi_of_match);
1046
1047static 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};
1056module_platform_driver(scpi_driver);
1057
1058MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1059MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1060MODULE_LICENSE("GPL v2");
1061