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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.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	if (!buf.opp_count)
 634		return ERR_PTR(-ENOENT);
 635
 636	info = kmalloc(sizeof(*info), GFP_KERNEL);
 637	if (!info)
 638		return ERR_PTR(-ENOMEM);
 639
 640	info->count = buf.opp_count;
 641	info->latency = le16_to_cpu(buf.latency) * 1000; /* uS to nS */
 642
 643	info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
 644	if (!info->opps) {
 645		kfree(info);
 646		return ERR_PTR(-ENOMEM);
 647	}
 648
 649	for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
 650		opp->freq = le32_to_cpu(buf.opps[i].freq);
 651		opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
 652	}
 653
 654	sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
 655
 656	scpi_info->dvfs[domain] = info;
 657	return info;
 658}
 659
 660static int scpi_dev_domain_id(struct device *dev)
 661{
 662	struct of_phandle_args clkspec;
 663
 664	if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
 665				       0, &clkspec))
 666		return -EINVAL;
 667
 668	return clkspec.args[0];
 669}
 670
 671static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
 672{
 673	int domain = scpi_dev_domain_id(dev);
 674
 675	if (domain < 0)
 676		return ERR_PTR(domain);
 677
 678	return scpi_dvfs_get_info(domain);
 679}
 680
 681static int scpi_dvfs_get_transition_latency(struct device *dev)
 682{
 683	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 684
 685	if (IS_ERR(info))
 686		return PTR_ERR(info);
 687
 688	return info->latency;
 689}
 690
 691static int scpi_dvfs_add_opps_to_device(struct device *dev)
 692{
 693	int idx, ret;
 694	struct scpi_opp *opp;
 695	struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 696
 697	if (IS_ERR(info))
 698		return PTR_ERR(info);
 699
 700	if (!info->opps)
 701		return -EIO;
 702
 703	for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
 704		ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
 705		if (ret) {
 706			dev_warn(dev, "failed to add opp %uHz %umV\n",
 707				 opp->freq, opp->m_volt);
 708			while (idx-- > 0)
 709				dev_pm_opp_remove(dev, (--opp)->freq);
 710			return ret;
 711		}
 712	}
 713	return 0;
 714}
 715
 716static int scpi_sensor_get_capability(u16 *sensors)
 717{
 718	__le16 cap;
 719	int ret;
 720
 721	ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap,
 722				sizeof(cap));
 723	if (!ret)
 724		*sensors = le16_to_cpu(cap);
 725
 726	return ret;
 727}
 728
 729static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
 730{
 731	__le16 id = cpu_to_le16(sensor_id);
 732	struct _scpi_sensor_info _info;
 733	int ret;
 734
 735	ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
 736				&_info, sizeof(_info));
 737	if (!ret) {
 738		memcpy(info, &_info, sizeof(*info));
 739		info->sensor_id = le16_to_cpu(_info.sensor_id);
 740	}
 741
 742	return ret;
 743}
 744
 745static int scpi_sensor_get_value(u16 sensor, u64 *val)
 746{
 747	__le16 id = cpu_to_le16(sensor);
 748	__le64 value;
 749	int ret;
 750
 751	ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
 752				&value, sizeof(value));
 753	if (ret)
 754		return ret;
 755
 756	if (scpi_info->is_legacy)
 757		/* only 32-bits supported, upper 32 bits can be junk */
 758		*val = le32_to_cpup((__le32 *)&value);
 759	else
 760		*val = le64_to_cpu(value);
 761
 762	return 0;
 763}
 764
 765static int scpi_device_get_power_state(u16 dev_id)
 766{
 767	int ret;
 768	u8 pstate;
 769	__le16 id = cpu_to_le16(dev_id);
 770
 771	ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
 772				sizeof(id), &pstate, sizeof(pstate));
 773	return ret ? ret : pstate;
 774}
 775
 776static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
 777{
 778	int stat;
 779	struct dev_pstate_set dev_set = {
 780		.dev_id = cpu_to_le16(dev_id),
 781		.pstate = pstate,
 782	};
 783
 784	return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
 785				 sizeof(dev_set), &stat, sizeof(stat));
 786}
 787
 788static struct scpi_ops scpi_ops = {
 789	.get_version = scpi_get_version,
 790	.clk_get_range = scpi_clk_get_range,
 791	.clk_get_val = scpi_clk_get_val,
 792	.clk_set_val = scpi_clk_set_val,
 793	.dvfs_get_idx = scpi_dvfs_get_idx,
 794	.dvfs_set_idx = scpi_dvfs_set_idx,
 795	.dvfs_get_info = scpi_dvfs_get_info,
 796	.device_domain_id = scpi_dev_domain_id,
 797	.get_transition_latency = scpi_dvfs_get_transition_latency,
 798	.add_opps_to_device = scpi_dvfs_add_opps_to_device,
 799	.sensor_get_capability = scpi_sensor_get_capability,
 800	.sensor_get_info = scpi_sensor_get_info,
 801	.sensor_get_value = scpi_sensor_get_value,
 802	.device_get_power_state = scpi_device_get_power_state,
 803	.device_set_power_state = scpi_device_set_power_state,
 804};
 805
 806struct scpi_ops *get_scpi_ops(void)
 807{
 808	return scpi_info ? scpi_info->scpi_ops : NULL;
 809}
 810EXPORT_SYMBOL_GPL(get_scpi_ops);
 811
 812static int scpi_init_versions(struct scpi_drvinfo *info)
 813{
 814	int ret;
 815	struct scp_capabilities caps;
 816
 817	ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
 818				&caps, sizeof(caps));
 819	if (!ret) {
 820		info->protocol_version = le32_to_cpu(caps.protocol_version);
 821		info->firmware_version = le32_to_cpu(caps.platform_version);
 822	}
 823	/* Ignore error if not implemented */
 824	if (info->is_legacy && ret == -EOPNOTSUPP)
 825		return 0;
 826
 827	return ret;
 828}
 829
 830static ssize_t protocol_version_show(struct device *dev,
 831				     struct device_attribute *attr, char *buf)
 832{
 833	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 834
 835	return sprintf(buf, "%lu.%lu\n",
 836		FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
 837		FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version));
 838}
 839static DEVICE_ATTR_RO(protocol_version);
 840
 841static ssize_t firmware_version_show(struct device *dev,
 842				     struct device_attribute *attr, char *buf)
 843{
 844	struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 845
 846	return sprintf(buf, "%lu.%lu.%lu\n",
 847		FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
 848		FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
 849		FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
 850}
 851static DEVICE_ATTR_RO(firmware_version);
 852
 853static struct attribute *versions_attrs[] = {
 854	&dev_attr_firmware_version.attr,
 855	&dev_attr_protocol_version.attr,
 856	NULL,
 857};
 858ATTRIBUTE_GROUPS(versions);
 859
 860static void scpi_free_channels(void *data)
 861{
 862	struct scpi_drvinfo *info = data;
 863	int i;
 864
 865	for (i = 0; i < info->num_chans; i++)
 866		mbox_free_channel(info->channels[i].chan);
 867}
 868
 869static void scpi_remove(struct platform_device *pdev)
 870{
 871	int i;
 872	struct scpi_drvinfo *info = platform_get_drvdata(pdev);
 873
 874	scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
 875
 876	for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
 877		kfree(info->dvfs[i]->opps);
 878		kfree(info->dvfs[i]);
 879	}
 880}
 881
 882#define MAX_SCPI_XFERS		10
 883static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
 884{
 885	int i;
 886	struct scpi_xfer *xfers;
 887
 888	xfers = devm_kcalloc(dev, MAX_SCPI_XFERS, sizeof(*xfers), GFP_KERNEL);
 889	if (!xfers)
 890		return -ENOMEM;
 891
 892	ch->xfers = xfers;
 893	for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
 894		init_completion(&xfers->done);
 895		list_add_tail(&xfers->node, &ch->xfers_list);
 896	}
 897
 898	return 0;
 899}
 900
 901static const struct of_device_id shmem_of_match[] __maybe_unused = {
 902	{ .compatible = "amlogic,meson-gxbb-scp-shmem", },
 903	{ .compatible = "amlogic,meson-axg-scp-shmem", },
 904	{ .compatible = "arm,juno-scp-shmem", },
 905	{ .compatible = "arm,scp-shmem", },
 906	{ }
 907};
 908
 909static int scpi_probe(struct platform_device *pdev)
 910{
 911	int count, idx, ret;
 912	struct resource res;
 913	struct device *dev = &pdev->dev;
 914	struct device_node *np = dev->of_node;
 915	struct scpi_drvinfo *scpi_drvinfo;
 916
 917	scpi_drvinfo = devm_kzalloc(dev, sizeof(*scpi_drvinfo), GFP_KERNEL);
 918	if (!scpi_drvinfo)
 919		return -ENOMEM;
 920
 921	scpi_drvinfo->is_legacy = !!device_get_match_data(dev);
 922
 923	count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 924	if (count < 0) {
 925		dev_err(dev, "no mboxes property in '%pOF'\n", np);
 926		return -ENODEV;
 927	}
 928
 929	scpi_drvinfo->channels =
 930		devm_kcalloc(dev, count, sizeof(struct scpi_chan), GFP_KERNEL);
 931	if (!scpi_drvinfo->channels)
 932		return -ENOMEM;
 933
 934	ret = devm_add_action(dev, scpi_free_channels, scpi_drvinfo);
 935	if (ret)
 936		return ret;
 937
 938	for (; scpi_drvinfo->num_chans < count; scpi_drvinfo->num_chans++) {
 939		resource_size_t size;
 940		int idx = scpi_drvinfo->num_chans;
 941		struct scpi_chan *pchan = scpi_drvinfo->channels + idx;
 942		struct mbox_client *cl = &pchan->cl;
 943		struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 944
 945		if (!of_match_node(shmem_of_match, shmem))
 946			return -ENXIO;
 947
 948		ret = of_address_to_resource(shmem, 0, &res);
 949		of_node_put(shmem);
 950		if (ret) {
 951			dev_err(dev, "failed to get SCPI payload mem resource\n");
 952			return ret;
 953		}
 954
 955		size = resource_size(&res);
 956		pchan->rx_payload = devm_ioremap(dev, res.start, size);
 957		if (!pchan->rx_payload) {
 958			dev_err(dev, "failed to ioremap SCPI payload\n");
 959			return -EADDRNOTAVAIL;
 960		}
 961		pchan->tx_payload = pchan->rx_payload + (size >> 1);
 962
 963		cl->dev = dev;
 964		cl->rx_callback = scpi_handle_remote_msg;
 965		cl->tx_prepare = scpi_tx_prepare;
 966		cl->tx_block = true;
 967		cl->tx_tout = 20;
 968		cl->knows_txdone = false; /* controller can't ack */
 969
 970		INIT_LIST_HEAD(&pchan->rx_pending);
 971		INIT_LIST_HEAD(&pchan->xfers_list);
 972		spin_lock_init(&pchan->rx_lock);
 973		mutex_init(&pchan->xfers_lock);
 974
 975		ret = scpi_alloc_xfer_list(dev, pchan);
 976		if (!ret) {
 977			pchan->chan = mbox_request_channel(cl, idx);
 978			if (!IS_ERR(pchan->chan))
 979				continue;
 980			ret = PTR_ERR(pchan->chan);
 981			if (ret != -EPROBE_DEFER)
 982				dev_err(dev, "failed to get channel%d err %d\n",
 983					idx, ret);
 984		}
 985		return ret;
 986	}
 987
 988	scpi_drvinfo->commands = scpi_std_commands;
 989
 990	platform_set_drvdata(pdev, scpi_drvinfo);
 991
 992	if (scpi_drvinfo->is_legacy) {
 993		/* Replace with legacy variants */
 994		scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
 995		scpi_drvinfo->commands = scpi_legacy_commands;
 996
 997		/* Fill priority bitmap */
 998		for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
 999			set_bit(legacy_hpriority_cmds[idx],
1000				scpi_drvinfo->cmd_priority);
1001	}
1002
1003	scpi_info = scpi_drvinfo;
1004
1005	ret = scpi_init_versions(scpi_drvinfo);
1006	if (ret) {
1007		dev_err(dev, "incorrect or no SCP firmware found\n");
1008		scpi_info = NULL;
1009		return ret;
1010	}
1011
1012	if (scpi_drvinfo->is_legacy && !scpi_drvinfo->protocol_version &&
1013	    !scpi_drvinfo->firmware_version)
1014		dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
1015	else
1016		dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1017			 FIELD_GET(PROTO_REV_MAJOR_MASK,
1018				   scpi_drvinfo->protocol_version),
1019			 FIELD_GET(PROTO_REV_MINOR_MASK,
1020				   scpi_drvinfo->protocol_version),
1021			 FIELD_GET(FW_REV_MAJOR_MASK,
1022				   scpi_drvinfo->firmware_version),
1023			 FIELD_GET(FW_REV_MINOR_MASK,
1024				   scpi_drvinfo->firmware_version),
1025			 FIELD_GET(FW_REV_PATCH_MASK,
1026				   scpi_drvinfo->firmware_version));
1027
1028	scpi_drvinfo->scpi_ops = &scpi_ops;
1029
1030	ret = devm_of_platform_populate(dev);
1031	if (ret)
1032		scpi_info = NULL;
1033
1034	return ret;
1035}
1036
1037static const struct of_device_id scpi_of_match[] = {
1038	{.compatible = "arm,scpi"},
1039	{.compatible = "arm,scpi-pre-1.0", .data = (void *)1UL },
1040	{},
1041};
1042
1043MODULE_DEVICE_TABLE(of, scpi_of_match);
1044
1045static struct platform_driver scpi_driver = {
1046	.driver = {
1047		.name = "scpi_protocol",
1048		.of_match_table = scpi_of_match,
1049		.dev_groups = versions_groups,
1050	},
1051	.probe = scpi_probe,
1052	.remove = scpi_remove,
1053};
1054module_platform_driver(scpi_driver);
1055
1056MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1057MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1058MODULE_LICENSE("GPL v2");