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   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");