linux/drivers/firmware/arm_scpi.c
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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 (scpi_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 int scpi_probe(struct platform_device *pdev)
 903{
 904        int count, idx, ret;
 905        struct resource res;
 906        struct device *dev = &pdev->dev;
 907        struct device_node *np = dev->of_node;
 908
 909        scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
 910        if (!scpi_info)
 911                return -ENOMEM;
 912
 913        if (of_match_device(legacy_scpi_of_match, &pdev->dev))
 914                scpi_info->is_legacy = true;
 915
 916        count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 917        if (count < 0) {
 918                dev_err(dev, "no mboxes property in '%pOF'\n", np);
 919                return -ENODEV;
 920        }
 921
 922        scpi_info->channels = devm_kcalloc(dev, count, sizeof(struct scpi_chan),
 923                                           GFP_KERNEL);
 924        if (!scpi_info->channels)
 925                return -ENOMEM;
 926
 927        ret = devm_add_action(dev, scpi_free_channels, scpi_info);
 928        if (ret)
 929                return ret;
 930
 931        for (; scpi_info->num_chans < count; scpi_info->num_chans++) {
 932                resource_size_t size;
 933                int idx = scpi_info->num_chans;
 934                struct scpi_chan *pchan = scpi_info->channels + idx;
 935                struct mbox_client *cl = &pchan->cl;
 936                struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 937
 938                ret = of_address_to_resource(shmem, 0, &res);
 939                of_node_put(shmem);
 940                if (ret) {
 941                        dev_err(dev, "failed to get SCPI payload mem resource\n");
 942                        return ret;
 943                }
 944
 945                size = resource_size(&res);
 946                pchan->rx_payload = devm_ioremap(dev, res.start, size);
 947                if (!pchan->rx_payload) {
 948                        dev_err(dev, "failed to ioremap SCPI payload\n");
 949                        return -EADDRNOTAVAIL;
 950                }
 951                pchan->tx_payload = pchan->rx_payload + (size >> 1);
 952
 953                cl->dev = dev;
 954                cl->rx_callback = scpi_handle_remote_msg;
 955                cl->tx_prepare = scpi_tx_prepare;
 956                cl->tx_block = true;
 957                cl->tx_tout = 20;
 958                cl->knows_txdone = false; /* controller can't ack */
 959
 960                INIT_LIST_HEAD(&pchan->rx_pending);
 961                INIT_LIST_HEAD(&pchan->xfers_list);
 962                spin_lock_init(&pchan->rx_lock);
 963                mutex_init(&pchan->xfers_lock);
 964
 965                ret = scpi_alloc_xfer_list(dev, pchan);
 966                if (!ret) {
 967                        pchan->chan = mbox_request_channel(cl, idx);
 968                        if (!IS_ERR(pchan->chan))
 969                                continue;
 970                        ret = PTR_ERR(pchan->chan);
 971                        if (ret != -EPROBE_DEFER)
 972                                dev_err(dev, "failed to get channel%d err %d\n",
 973                                        idx, ret);
 974                }
 975                return ret;
 976        }
 977
 978        scpi_info->commands = scpi_std_commands;
 979
 980        platform_set_drvdata(pdev, scpi_info);
 981
 982        if (scpi_info->is_legacy) {
 983                /* Replace with legacy variants */
 984                scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
 985                scpi_info->commands = scpi_legacy_commands;
 986
 987                /* Fill priority bitmap */
 988                for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
 989                        set_bit(legacy_hpriority_cmds[idx],
 990                                scpi_info->cmd_priority);
 991        }
 992
 993        ret = scpi_init_versions(scpi_info);
 994        if (ret) {
 995                dev_err(dev, "incorrect or no SCP firmware found\n");
 996                return ret;
 997        }
 998
 999        if (scpi_info->is_legacy && !scpi_info->protocol_version &&
1000            !scpi_info->firmware_version)
1001                dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
1002        else
1003                dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1004                         FIELD_GET(PROTO_REV_MAJOR_MASK,
1005                                   scpi_info->protocol_version),
1006                         FIELD_GET(PROTO_REV_MINOR_MASK,
1007                                   scpi_info->protocol_version),
1008                         FIELD_GET(FW_REV_MAJOR_MASK,
1009                                   scpi_info->firmware_version),
1010                         FIELD_GET(FW_REV_MINOR_MASK,
1011                                   scpi_info->firmware_version),
1012                         FIELD_GET(FW_REV_PATCH_MASK,
1013                                   scpi_info->firmware_version));
1014        scpi_info->scpi_ops = &scpi_ops;
1015
1016        return devm_of_platform_populate(dev);
1017}
1018
1019static const struct of_device_id scpi_of_match[] = {
1020        {.compatible = "arm,scpi"},
1021        {.compatible = "arm,scpi-pre-1.0"},
1022        {},
1023};
1024
1025MODULE_DEVICE_TABLE(of, scpi_of_match);
1026
1027static struct platform_driver scpi_driver = {
1028        .driver = {
1029                .name = "scpi_protocol",
1030                .of_match_table = scpi_of_match,
1031                .dev_groups = versions_groups,
1032        },
1033        .probe = scpi_probe,
1034        .remove = scpi_remove,
1035};
1036module_platform_driver(scpi_driver);
1037
1038MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1039MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1040MODULE_LICENSE("GPL v2");
1041