drivers/firmware/arm_scpi.c

   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
  67 enum 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 */
  85 enum 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 */
 119 enum 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 */
 156 static 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 */
 174 enum 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
 190 static 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
 205 static 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
 220 struct 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
 232 struct 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
 245 struct 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  */
 262 struct scpi_shared_mem {
 263         __le32 command;
 264         __le32 status;
 265         u8 payload[];
 266 } __packed;
 267
 268 struct legacy_scpi_shared_mem {
 269         __le32 status;
 270         u8 payload[];
 271 } __packed;
 272
 273 struct scp_capabilities {
 274         __le32 protocol_version;
 275         __le32 event_version;
 276         __le32 platform_version;
 277         __le32 commands[4];
 278 } __packed;
 279
 280 struct clk_get_info {
 281         __le16 id;
 282         __le16 flags;
 283         __le32 min_rate;
 284         __le32 max_rate;
 285         u8 name[20];
 286 } __packed;
 287
 288 struct clk_set_value {
 289         __le16 id;
 290         __le16 reserved;
 291         __le32 rate;
 292 } __packed;
 293
 294 struct legacy_clk_set_value {
 295         __le32 rate;
 296         __le16 id;
 297         __le16 reserved;
 298 } __packed;
 299
 300 struct 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
 310 struct dvfs_set {
 311         u8 domain;
 312         u8 index;
 313 } __packed;
 314
 315 struct _scpi_sensor_info {
 316         __le16 sensor_id;
 317         u8 class;
 318         u8 trigger_type;
 319         char name[20];
 320 };
 321
 322 struct dev_pstate_set {
 323         __le16 dev_id;
 324         u8 pstate;
 325 } __packed;
 326
 327 static struct scpi_drvinfo *scpi_info;
 328
 329 static 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
 346 static 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
 353 static 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
 409 static 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
 421 static 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
 448 static 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
 463 static 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
 470 static 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;
 517 out:
 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
 526 static u32 scpi_get_version(void)
 527 {
 528         return scpi_info->protocol_version;
 529 }
 530
 531 static int
 532 scpi_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
 547 static 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
 561 static 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
 573 static 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
 585 static 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
 596 static 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
 605 static 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
 612 static 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
 654 static 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
 665 static 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
 675 static 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
 685 static 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
 710 static 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
 723 static 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
 739 static 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
 759 static 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
 770 static 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
 782 static 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
 800 struct scpi_ops *get_scpi_ops(void)
 801 {
 802         return scpi_info ? scpi_info->scpi_ops : NULL;
 803 }
 804 EXPORT_SYMBOL_GPL(get_scpi_ops);
 805
 806 static 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
 824 static 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 }
 833 static DEVICE_ATTR_RO(protocol_version);
 834
 835 static 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 }
 845 static DEVICE_ATTR_RO(firmware_version);
 846
 847 static struct attribute *versions_attrs[] = {
 848         &dev_attr_firmware_version.attr,
 849         &dev_attr_protocol_version.attr,
 850         NULL,
 851 };
 852 ATTRIBUTE_GROUPS(versions);
 853
 854 static 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
 863 static 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
 879 static 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
 897 static const struct of_device_id legacy_scpi_of_match[] = {
 898         {.compatible = "arm,scpi-pre-1.0"},
 899         {},
 900 };
 901
 902 static const struct of_device_id shmem_of_match[] __maybe_unused = {
 903         { .compatible = "amlogic,meson-gxbb-scp-shmem", },
 904         { .compatible = "amlogic,meson-axg-scp-shmem", },
 905         { .compatible = "arm,juno-scp-shmem", },
 906         { .compatible = "arm,scp-shmem", },
 907         { }
 908 };
 909
 910 static int scpi_probe(struct platform_device *pdev)
 911 {
 912         int count, idx, ret;
 913         struct resource res;
 914         struct device *dev = &pdev->dev;
 915         struct device_node *np = dev->of_node;
 916
 917         scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
 918         if (!scpi_info)
 919                 return -ENOMEM;
 920
 921         if (of_match_device(legacy_scpi_of_match, &pdev->dev))
 922                 scpi_info->is_legacy = true;
 923
 924         count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 925         if (count < 0) {
 926                 dev_err(dev, "no mboxes property in '%pOF'\n", np);
 927                 return -ENODEV;
 928         }
 929
 930         scpi_info->channels = devm_kcalloc(dev, count, sizeof(struct scpi_chan),
 931                                            GFP_KERNEL);
 932         if (!scpi_info->channels)
 933                 return -ENOMEM;
 934
 935         ret = devm_add_action(dev, scpi_free_channels, scpi_info);
 936         if (ret)
 937                 return ret;
 938
 939         for (; scpi_info->num_chans < count; scpi_info->num_chans++) {
 940                 resource_size_t size;
 941                 int idx = scpi_info->num_chans;
 942                 struct scpi_chan *pchan = scpi_info->channels + idx;
 943                 struct mbox_client *cl = &pchan->cl;
 944                 struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 945
 946                 if (!of_match_node(shmem_of_match, shmem))
 947                         return -ENXIO;
 948
 949                 ret = of_address_to_resource(shmem, 0, &res);
 950                 of_node_put(shmem);
 951                 if (ret) {
 952                         dev_err(dev, "failed to get SCPI payload mem resource\n");
 953                         return ret;
 954                 }
 955
 956                 size = resource_size(&res);
 957                 pchan->rx_payload = devm_ioremap(dev, res.start, size);
 958                 if (!pchan->rx_payload) {
 959                         dev_err(dev, "failed to ioremap SCPI payload\n");
 960                         return -EADDRNOTAVAIL;
 961                 }
 962                 pchan->tx_payload = pchan->rx_payload + (size >> 1);
 963
 964                 cl->dev = dev;
 965                 cl->rx_callback = scpi_handle_remote_msg;
 966                 cl->tx_prepare = scpi_tx_prepare;
 967                 cl->tx_block = true;
 968                 cl->tx_tout = 20;
 969                 cl->knows_txdone = false; /* controller can't ack */
 970
 971                 INIT_LIST_HEAD(&pchan->rx_pending);
 972                 INIT_LIST_HEAD(&pchan->xfers_list);
 973                 spin_lock_init(&pchan->rx_lock);
 974                 mutex_init(&pchan->xfers_lock);
 975
 976                 ret = scpi_alloc_xfer_list(dev, pchan);
 977                 if (!ret) {
 978                         pchan->chan = mbox_request_channel(cl, idx);
 979                         if (!IS_ERR(pchan->chan))
 980                                 continue;
 981                         ret = PTR_ERR(pchan->chan);
 982                         if (ret != -EPROBE_DEFER)
 983                                 dev_err(dev, "failed to get channel%d err %d\n",
 984                                         idx, ret);
 985                 }
 986                 return ret;
 987         }
 988
 989         scpi_info->commands = scpi_std_commands;
 990
 991         platform_set_drvdata(pdev, scpi_info);
 992
 993         if (scpi_info->is_legacy) {
 994                 /* Replace with legacy variants */
 995                 scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
 996                 scpi_info->commands = scpi_legacy_commands;
 997
 998                 /* Fill priority bitmap */
 999                 for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
1000                         set_bit(legacy_hpriority_cmds[idx],
1001                                 scpi_info->cmd_priority);
1002         }
1003
1004         ret = scpi_init_versions(scpi_info);
1005         if (ret) {
1006                 dev_err(dev, "incorrect or no SCP firmware found\n");
1007                 return ret;
1008         }
1009
1010         if (scpi_info->is_legacy && !scpi_info->protocol_version &&
1011             !scpi_info->firmware_version)
1012                 dev_info(dev, "SCP Protocol legacy pre-1.0 firmware\n");
1013         else
1014                 dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1015                          FIELD_GET(PROTO_REV_MAJOR_MASK,
1016                                    scpi_info->protocol_version),
1017                          FIELD_GET(PROTO_REV_MINOR_MASK,
1018                                    scpi_info->protocol_version),
1019                          FIELD_GET(FW_REV_MAJOR_MASK,
1020                                    scpi_info->firmware_version),
1021                          FIELD_GET(FW_REV_MINOR_MASK,
1022                                    scpi_info->firmware_version),
1023                          FIELD_GET(FW_REV_PATCH_MASK,
1024                                    scpi_info->firmware_version));
1025         scpi_info->scpi_ops = &scpi_ops;
1026
1027         return devm_of_platform_populate(dev);
1028 }
1029
1030 static const struct of_device_id scpi_of_match[] = {
1031         {.compatible = "arm,scpi"},
1032         {.compatible = "arm,scpi-pre-1.0"},
1033         {},
1034 };
1035
1036 MODULE_DEVICE_TABLE(of, scpi_of_match);
1037
1038 static struct platform_driver scpi_driver = {
1039         .driver = {
1040                 .name = "scpi_protocol",
1041                 .of_match_table = scpi_of_match,
1042                 .dev_groups = versions_groups,
1043         },
1044         .probe = scpi_probe,
1045         .remove = scpi_remove,
1046 };
1047 module_platform_driver(scpi_driver);
1048
1049 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1050 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1051 MODULE_LICENSE("GPL v2");