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