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[0];
 266} __packed;
 267
 268struct legacy_scpi_shared_mem {
 269        __le32 status;
 270        u8 payload[0];
 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
 556        return ret ? ret : le32_to_cpu(rate);
 557}
 558
 559static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
 560{
 561        int stat;
 562        struct clk_set_value clk = {
 563                .id = cpu_to_le16(clk_id),
 564                .rate = cpu_to_le32(rate)
 565        };
 566
 567        return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 568                                 &stat, sizeof(stat));
 569}
 570
 571static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
 572{
 573        int stat;
 574        struct legacy_clk_set_value clk = {
 575                .id = cpu_to_le16(clk_id),
 576                .rate = cpu_to_le32(rate)
 577        };
 578
 579        return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 580                                 &stat, sizeof(stat));
 581}
 582
 583static int scpi_dvfs_get_idx(u8 domain)
 584{
 585        int ret;
 586        u8 dvfs_idx;
 587
 588        ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
 589                                &dvfs_idx, sizeof(dvfs_idx));
 590
 591        return ret ? ret : dvfs_idx;
 592}
 593
 594static int scpi_dvfs_set_idx(u8 domain, u8 index)
 595{
 596        int stat;
 597        struct dvfs_set dvfs = {domain, index};
 598
 599        return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
 600                                 &stat, sizeof(stat));
 601}
 602
 603static int opp_cmp_func(const void *opp1, const void *opp2)
 604{
 605        const struct scpi_opp *t1 = opp1, *t2 = opp2;
 606
 607        return t1->freq - t2->freq;
 608}
 609
 610static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
 611{
 612        struct scpi_dvfs_info *info;
 613        struct scpi_opp *opp;
 614        struct dvfs_info buf;
 615        int ret, i;
 616
 617        if (domain >= MAX_DVFS_DOMAINS)
 618                return ERR_PTR(-EINVAL);
 619
 620        if (scpi_info->dvfs[domain])    /* data already populated */
 621                return scpi_info->dvfs[domain];
 622
 623        ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
 624                                &buf, sizeof(buf));
 625        if (ret)
 626                return ERR_PTR(ret);
 627
 628        info = kmalloc(sizeof(*info), GFP_KERNEL);
 629        if (!info)
 630                return ERR_PTR(-ENOMEM);
 631
 632        info->count = buf.opp_count;
 633        info->latency = le16_to_cpu(buf.latency) * 1000; /* uS to nS */
 634
 635        info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
 636        if (!info->opps) {
 637                kfree(info);
 638                return ERR_PTR(-ENOMEM);
 639        }
 640
 641        for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
 642                opp->freq = le32_to_cpu(buf.opps[i].freq);
 643                opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
 644        }
 645
 646        sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
 647
 648        scpi_info->dvfs[domain] = info;
 649        return info;
 650}
 651
 652static int scpi_dev_domain_id(struct device *dev)
 653{
 654        struct of_phandle_args clkspec;
 655
 656        if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
 657                                       0, &clkspec))
 658                return -EINVAL;
 659
 660        return clkspec.args[0];
 661}
 662
 663static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
 664{
 665        int domain = scpi_dev_domain_id(dev);
 666
 667        if (domain < 0)
 668                return ERR_PTR(domain);
 669
 670        return scpi_dvfs_get_info(domain);
 671}
 672
 673static int scpi_dvfs_get_transition_latency(struct device *dev)
 674{
 675        struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 676
 677        if (IS_ERR(info))
 678                return PTR_ERR(info);
 679
 680        return info->latency;
 681}
 682
 683static int scpi_dvfs_add_opps_to_device(struct device *dev)
 684{
 685        int idx, ret;
 686        struct scpi_opp *opp;
 687        struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 688
 689        if (IS_ERR(info))
 690                return PTR_ERR(info);
 691
 692        if (!info->opps)
 693                return -EIO;
 694
 695        for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
 696                ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
 697                if (ret) {
 698                        dev_warn(dev, "failed to add opp %uHz %umV\n",
 699                                 opp->freq, opp->m_volt);
 700                        while (idx-- > 0)
 701                                dev_pm_opp_remove(dev, (--opp)->freq);
 702                        return ret;
 703                }
 704        }
 705        return 0;
 706}
 707
 708static int scpi_sensor_get_capability(u16 *sensors)
 709{
 710        __le16 cap;
 711        int ret;
 712
 713        ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap,
 714                                sizeof(cap));
 715        if (!ret)
 716                *sensors = le16_to_cpu(cap);
 717
 718        return ret;
 719}
 720
 721static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
 722{
 723        __le16 id = cpu_to_le16(sensor_id);
 724        struct _scpi_sensor_info _info;
 725        int ret;
 726
 727        ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
 728                                &_info, sizeof(_info));
 729        if (!ret) {
 730                memcpy(info, &_info, sizeof(*info));
 731                info->sensor_id = le16_to_cpu(_info.sensor_id);
 732        }
 733
 734        return ret;
 735}
 736
 737static int scpi_sensor_get_value(u16 sensor, u64 *val)
 738{
 739        __le16 id = cpu_to_le16(sensor);
 740        __le64 value;
 741        int ret;
 742
 743        ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
 744                                &value, sizeof(value));
 745        if (ret)
 746                return ret;
 747
 748        if (scpi_info->is_legacy)
 749                /* only 32-bits supported, upper 32 bits can be junk */
 750                *val = le32_to_cpup((__le32 *)&value);
 751        else
 752                *val = le64_to_cpu(value);
 753
 754        return 0;
 755}
 756
 757static int scpi_device_get_power_state(u16 dev_id)
 758{
 759        int ret;
 760        u8 pstate;
 761        __le16 id = cpu_to_le16(dev_id);
 762
 763        ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
 764                                sizeof(id), &pstate, sizeof(pstate));
 765        return ret ? ret : pstate;
 766}
 767
 768static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
 769{
 770        int stat;
 771        struct dev_pstate_set dev_set = {
 772                .dev_id = cpu_to_le16(dev_id),
 773                .pstate = pstate,
 774        };
 775
 776        return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
 777                                 sizeof(dev_set), &stat, sizeof(stat));
 778}
 779
 780static struct scpi_ops scpi_ops = {
 781        .get_version = scpi_get_version,
 782        .clk_get_range = scpi_clk_get_range,
 783        .clk_get_val = scpi_clk_get_val,
 784        .clk_set_val = scpi_clk_set_val,
 785        .dvfs_get_idx = scpi_dvfs_get_idx,
 786        .dvfs_set_idx = scpi_dvfs_set_idx,
 787        .dvfs_get_info = scpi_dvfs_get_info,
 788        .device_domain_id = scpi_dev_domain_id,
 789        .get_transition_latency = scpi_dvfs_get_transition_latency,
 790        .add_opps_to_device = scpi_dvfs_add_opps_to_device,
 791        .sensor_get_capability = scpi_sensor_get_capability,
 792        .sensor_get_info = scpi_sensor_get_info,
 793        .sensor_get_value = scpi_sensor_get_value,
 794        .device_get_power_state = scpi_device_get_power_state,
 795        .device_set_power_state = scpi_device_set_power_state,
 796};
 797
 798struct scpi_ops *get_scpi_ops(void)
 799{
 800        return scpi_info ? scpi_info->scpi_ops : NULL;
 801}
 802EXPORT_SYMBOL_GPL(get_scpi_ops);
 803
 804static int scpi_init_versions(struct scpi_drvinfo *info)
 805{
 806        int ret;
 807        struct scp_capabilities caps;
 808
 809        ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
 810                                &caps, sizeof(caps));
 811        if (!ret) {
 812                info->protocol_version = le32_to_cpu(caps.protocol_version);
 813                info->firmware_version = le32_to_cpu(caps.platform_version);
 814        }
 815        /* Ignore error if not implemented */
 816        if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
 817                return 0;
 818
 819        return ret;
 820}
 821
 822static ssize_t protocol_version_show(struct device *dev,
 823                                     struct device_attribute *attr, char *buf)
 824{
 825        struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 826
 827        return sprintf(buf, "%lu.%lu\n",
 828                FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
 829                FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version));
 830}
 831static DEVICE_ATTR_RO(protocol_version);
 832
 833static ssize_t firmware_version_show(struct device *dev,
 834                                     struct device_attribute *attr, char *buf)
 835{
 836        struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 837
 838        return sprintf(buf, "%lu.%lu.%lu\n",
 839                FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
 840                FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
 841                FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
 842}
 843static DEVICE_ATTR_RO(firmware_version);
 844
 845static struct attribute *versions_attrs[] = {
 846        &dev_attr_firmware_version.attr,
 847        &dev_attr_protocol_version.attr,
 848        NULL,
 849};
 850ATTRIBUTE_GROUPS(versions);
 851
 852static void scpi_free_channels(void *data)
 853{
 854        struct scpi_drvinfo *info = data;
 855        int i;
 856
 857        for (i = 0; i < info->num_chans; i++)
 858                mbox_free_channel(info->channels[i].chan);
 859}
 860
 861static int scpi_remove(struct platform_device *pdev)
 862{
 863        int i;
 864        struct scpi_drvinfo *info = platform_get_drvdata(pdev);
 865
 866        scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
 867
 868        for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
 869                kfree(info->dvfs[i]->opps);
 870                kfree(info->dvfs[i]);
 871        }
 872
 873        return 0;
 874}
 875
 876#define MAX_SCPI_XFERS          10
 877static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
 878{
 879        int i;
 880        struct scpi_xfer *xfers;
 881
 882        xfers = devm_kcalloc(dev, MAX_SCPI_XFERS, sizeof(*xfers), GFP_KERNEL);
 883        if (!xfers)
 884                return -ENOMEM;
 885
 886        ch->xfers = xfers;
 887        for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
 888                init_completion(&xfers->done);
 889                list_add_tail(&xfers->node, &ch->xfers_list);
 890        }
 891
 892        return 0;
 893}
 894
 895static const struct of_device_id legacy_scpi_of_match[] = {
 896        {.compatible = "arm,scpi-pre-1.0"},
 897        {},
 898};
 899
 900static int scpi_probe(struct platform_device *pdev)
 901{
 902        int count, idx, ret;
 903        struct resource res;
 904        struct device *dev = &pdev->dev;
 905        struct device_node *np = dev->of_node;
 906
 907        scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
 908        if (!scpi_info)
 909                return -ENOMEM;
 910
 911        if (of_match_device(legacy_scpi_of_match, &pdev->dev))
 912                scpi_info->is_legacy = true;
 913
 914        count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 915        if (count < 0) {
 916                dev_err(dev, "no mboxes property in '%pOF'\n", np);
 917                return -ENODEV;
 918        }
 919
 920        scpi_info->channels = devm_kcalloc(dev, count, sizeof(struct scpi_chan),
 921                                           GFP_KERNEL);
 922        if (!scpi_info->channels)
 923                return -ENOMEM;
 924
 925        ret = devm_add_action(dev, scpi_free_channels, scpi_info);
 926        if (ret)
 927                return ret;
 928
 929        for (; scpi_info->num_chans < count; scpi_info->num_chans++) {
 930                resource_size_t size;
 931                int idx = scpi_info->num_chans;
 932                struct scpi_chan *pchan = scpi_info->channels + idx;
 933                struct mbox_client *cl = &pchan->cl;
 934                struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 935
 936                ret = of_address_to_resource(shmem, 0, &res);
 937                of_node_put(shmem);
 938                if (ret) {
 939                        dev_err(dev, "failed to get SCPI payload mem resource\n");
 940                        return ret;
 941                }
 942
 943                size = resource_size(&res);
 944                pchan->rx_payload = devm_ioremap(dev, res.start, size);
 945                if (!pchan->rx_payload) {
 946                        dev_err(dev, "failed to ioremap SCPI payload\n");
 947                        return -EADDRNOTAVAIL;
 948                }
 949                pchan->tx_payload = pchan->rx_payload + (size >> 1);
 950
 951                cl->dev = dev;
 952                cl->rx_callback = scpi_handle_remote_msg;
 953                cl->tx_prepare = scpi_tx_prepare;
 954                cl->tx_block = true;
 955                cl->tx_tout = 20;
 956                cl->knows_txdone = false; /* controller can't ack */
 957
 958                INIT_LIST_HEAD(&pchan->rx_pending);
 959                INIT_LIST_HEAD(&pchan->xfers_list);
 960                spin_lock_init(&pchan->rx_lock);
 961                mutex_init(&pchan->xfers_lock);
 962
 963                ret = scpi_alloc_xfer_list(dev, pchan);
 964                if (!ret) {
 965                        pchan->chan = mbox_request_channel(cl, idx);
 966                        if (!IS_ERR(pchan->chan))
 967                                continue;
 968                        ret = PTR_ERR(pchan->chan);
 969                        if (ret != -EPROBE_DEFER)
 970                                dev_err(dev, "failed to get channel%d err %d\n",
 971                                        idx, ret);
 972                }
 973                return ret;
 974        }
 975
 976        scpi_info->commands = scpi_std_commands;
 977
 978        platform_set_drvdata(pdev, scpi_info);
 979
 980        if (scpi_info->is_legacy) {
 981                /* Replace with legacy variants */
 982                scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
 983                scpi_info->commands = scpi_legacy_commands;
 984
 985                /* Fill priority bitmap */
 986                for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
 987                        set_bit(legacy_hpriority_cmds[idx],
 988                                scpi_info->cmd_priority);
 989        }
 990
 991        ret = scpi_init_versions(scpi_info);
 992        if (ret) {
 993                dev_err(dev, "incorrect or no SCP firmware found\n");
 994                return ret;
 995        }
 996
 997        if (scpi_info->is_legacy && !scpi_info->protocol_version &&
 998            !scpi_info->firmware_version)
 999                dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
1000        else
1001                dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1002                         FIELD_GET(PROTO_REV_MAJOR_MASK,
1003                                   scpi_info->protocol_version),
1004                         FIELD_GET(PROTO_REV_MINOR_MASK,
1005                                   scpi_info->protocol_version),
1006                         FIELD_GET(FW_REV_MAJOR_MASK,
1007                                   scpi_info->firmware_version),
1008                         FIELD_GET(FW_REV_MINOR_MASK,
1009                                   scpi_info->firmware_version),
1010                         FIELD_GET(FW_REV_PATCH_MASK,
1011                                   scpi_info->firmware_version));
1012        scpi_info->scpi_ops = &scpi_ops;
1013
1014        return devm_of_platform_populate(dev);
1015}
1016
1017static const struct of_device_id scpi_of_match[] = {
1018        {.compatible = "arm,scpi"},
1019        {.compatible = "arm,scpi-pre-1.0"},
1020        {},
1021};
1022
1023MODULE_DEVICE_TABLE(of, scpi_of_match);
1024
1025static struct platform_driver scpi_driver = {
1026        .driver = {
1027                .name = "scpi_protocol",
1028                .of_match_table = scpi_of_match,
1029                .dev_groups = versions_groups,
1030        },
1031        .probe = scpi_probe,
1032        .remove = scpi_remove,
1033};
1034module_platform_driver(scpi_driver);
1035
1036MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1037MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1038MODULE_LICENSE("GPL v2");
1039