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