drivers/firmware/arm_scpi.c

   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_SHIFT            0
  50 #define CMD_ID_MASK             0x7f
  51 #define CMD_TOKEN_ID_SHIFT      8
  52 #define CMD_TOKEN_ID_MASK       0xff
  53 #define CMD_DATA_SIZE_SHIFT     16
  54 #define CMD_DATA_SIZE_MASK      0x1ff
  55 #define CMD_LEGACY_DATA_SIZE_SHIFT      20
  56 #define CMD_LEGACY_DATA_SIZE_MASK       0x1ff
  57 #define PACK_SCPI_CMD(cmd_id, tx_sz)                    \
  58         ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |   \
  59         (((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
  60 #define ADD_SCPI_TOKEN(cmd, token)                      \
  61         ((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
  62 #define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)                             \
  63         ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |                          \
  64         (((tx_sz) & CMD_LEGACY_DATA_SIZE_MASK) << CMD_LEGACY_DATA_SIZE_SHIFT))
  65
  66 #define CMD_SIZE(cmd)   (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
  67 #define CMD_LEGACY_SIZE(cmd)    (((cmd) >> CMD_LEGACY_DATA_SIZE_SHIFT) & \
  68                                         CMD_LEGACY_DATA_SIZE_MASK)
  69 #define CMD_UNIQ_MASK   (CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
  70 #define CMD_XTRACT_UNIQ(cmd)    ((cmd) & CMD_UNIQ_MASK)
  71
  72 #define SCPI_SLOT               0
  73
  74 #define MAX_DVFS_DOMAINS        8
  75 #define MAX_DVFS_OPPS           16
  76
  77 #define PROTO_REV_MAJOR_MASK    GENMASK(31, 16)
  78 #define PROTO_REV_MINOR_MASK    GENMASK(15, 0)
  79
  80 #define FW_REV_MAJOR_MASK       GENMASK(31, 24)
  81 #define FW_REV_MINOR_MASK       GENMASK(23, 16)
  82 #define FW_REV_PATCH_MASK       GENMASK(15, 0)
  83
  84 #define MAX_RX_TIMEOUT          (msecs_to_jiffies(30))
  85
  86 enum scpi_error_codes {
  87         SCPI_SUCCESS = 0, /* Success */
  88         SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
  89         SCPI_ERR_ALIGN = 2, /* Invalid alignment */
  90         SCPI_ERR_SIZE = 3, /* Invalid size */
  91         SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
  92         SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
  93         SCPI_ERR_RANGE = 6, /* Value out of range */
  94         SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
  95         SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
  96         SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
  97         SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
  98         SCPI_ERR_DEVICE = 11, /* Device error */
  99         SCPI_ERR_BUSY = 12, /* Device busy */
 100         SCPI_ERR_MAX
 101 };
 102
 103 /* SCPI Standard commands */
 104 enum scpi_std_cmd {
 105         SCPI_CMD_INVALID                = 0x00,
 106         SCPI_CMD_SCPI_READY             = 0x01,
 107         SCPI_CMD_SCPI_CAPABILITIES      = 0x02,
 108         SCPI_CMD_SET_CSS_PWR_STATE      = 0x03,
 109         SCPI_CMD_GET_CSS_PWR_STATE      = 0x04,
 110         SCPI_CMD_SET_SYS_PWR_STATE      = 0x05,
 111         SCPI_CMD_SET_CPU_TIMER          = 0x06,
 112         SCPI_CMD_CANCEL_CPU_TIMER       = 0x07,
 113         SCPI_CMD_DVFS_CAPABILITIES      = 0x08,
 114         SCPI_CMD_GET_DVFS_INFO          = 0x09,
 115         SCPI_CMD_SET_DVFS               = 0x0a,
 116         SCPI_CMD_GET_DVFS               = 0x0b,
 117         SCPI_CMD_GET_DVFS_STAT          = 0x0c,
 118         SCPI_CMD_CLOCK_CAPABILITIES     = 0x0d,
 119         SCPI_CMD_GET_CLOCK_INFO         = 0x0e,
 120         SCPI_CMD_SET_CLOCK_VALUE        = 0x0f,
 121         SCPI_CMD_GET_CLOCK_VALUE        = 0x10,
 122         SCPI_CMD_PSU_CAPABILITIES       = 0x11,
 123         SCPI_CMD_GET_PSU_INFO           = 0x12,
 124         SCPI_CMD_SET_PSU                = 0x13,
 125         SCPI_CMD_GET_PSU                = 0x14,
 126         SCPI_CMD_SENSOR_CAPABILITIES    = 0x15,
 127         SCPI_CMD_SENSOR_INFO            = 0x16,
 128         SCPI_CMD_SENSOR_VALUE           = 0x17,
 129         SCPI_CMD_SENSOR_CFG_PERIODIC    = 0x18,
 130         SCPI_CMD_SENSOR_CFG_BOUNDS      = 0x19,
 131         SCPI_CMD_SENSOR_ASYNC_VALUE     = 0x1a,
 132         SCPI_CMD_SET_DEVICE_PWR_STATE   = 0x1b,
 133         SCPI_CMD_GET_DEVICE_PWR_STATE   = 0x1c,
 134         SCPI_CMD_COUNT
 135 };
 136
 137 /* SCPI Legacy Commands */
 138 enum legacy_scpi_std_cmd {
 139         LEGACY_SCPI_CMD_INVALID                 = 0x00,
 140         LEGACY_SCPI_CMD_SCPI_READY              = 0x01,
 141         LEGACY_SCPI_CMD_SCPI_CAPABILITIES       = 0x02,
 142         LEGACY_SCPI_CMD_EVENT                   = 0x03,
 143         LEGACY_SCPI_CMD_SET_CSS_PWR_STATE       = 0x04,
 144         LEGACY_SCPI_CMD_GET_CSS_PWR_STATE       = 0x05,
 145         LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT      = 0x06,
 146         LEGACY_SCPI_CMD_GET_PWR_STATE_STAT      = 0x07,
 147         LEGACY_SCPI_CMD_SYS_PWR_STATE           = 0x08,
 148         LEGACY_SCPI_CMD_L2_READY                = 0x09,
 149         LEGACY_SCPI_CMD_SET_AP_TIMER            = 0x0a,
 150         LEGACY_SCPI_CMD_CANCEL_AP_TIME          = 0x0b,
 151         LEGACY_SCPI_CMD_DVFS_CAPABILITIES       = 0x0c,
 152         LEGACY_SCPI_CMD_GET_DVFS_INFO           = 0x0d,
 153         LEGACY_SCPI_CMD_SET_DVFS                = 0x0e,
 154         LEGACY_SCPI_CMD_GET_DVFS                = 0x0f,
 155         LEGACY_SCPI_CMD_GET_DVFS_STAT           = 0x10,
 156         LEGACY_SCPI_CMD_SET_RTC                 = 0x11,
 157         LEGACY_SCPI_CMD_GET_RTC                 = 0x12,
 158         LEGACY_SCPI_CMD_CLOCK_CAPABILITIES      = 0x13,
 159         LEGACY_SCPI_CMD_SET_CLOCK_INDEX         = 0x14,
 160         LEGACY_SCPI_CMD_SET_CLOCK_VALUE         = 0x15,
 161         LEGACY_SCPI_CMD_GET_CLOCK_VALUE         = 0x16,
 162         LEGACY_SCPI_CMD_PSU_CAPABILITIES        = 0x17,
 163         LEGACY_SCPI_CMD_SET_PSU                 = 0x18,
 164         LEGACY_SCPI_CMD_GET_PSU                 = 0x19,
 165         LEGACY_SCPI_CMD_SENSOR_CAPABILITIES     = 0x1a,
 166         LEGACY_SCPI_CMD_SENSOR_INFO             = 0x1b,
 167         LEGACY_SCPI_CMD_SENSOR_VALUE            = 0x1c,
 168         LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC     = 0x1d,
 169         LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS       = 0x1e,
 170         LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE      = 0x1f,
 171         LEGACY_SCPI_CMD_COUNT
 172 };
 173
 174 /* List all commands that are required to go through the high priority link */
 175 static int legacy_hpriority_cmds[] = {
 176         LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
 177         LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
 178         LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
 179         LEGACY_SCPI_CMD_SET_DVFS,
 180         LEGACY_SCPI_CMD_GET_DVFS,
 181         LEGACY_SCPI_CMD_SET_RTC,
 182         LEGACY_SCPI_CMD_GET_RTC,
 183         LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
 184         LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
 185         LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
 186         LEGACY_SCPI_CMD_SET_PSU,
 187         LEGACY_SCPI_CMD_GET_PSU,
 188         LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
 189         LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
 190 };
 191
 192 /* List all commands used by this driver, used as indexes */
 193 enum scpi_drv_cmds {
 194         CMD_SCPI_CAPABILITIES = 0,
 195         CMD_GET_CLOCK_INFO,
 196         CMD_GET_CLOCK_VALUE,
 197         CMD_SET_CLOCK_VALUE,
 198         CMD_GET_DVFS,
 199         CMD_SET_DVFS,
 200         CMD_GET_DVFS_INFO,
 201         CMD_SENSOR_CAPABILITIES,
 202         CMD_SENSOR_INFO,
 203         CMD_SENSOR_VALUE,
 204         CMD_SET_DEVICE_PWR_STATE,
 205         CMD_GET_DEVICE_PWR_STATE,
 206         CMD_MAX_COUNT,
 207 };
 208
 209 static int scpi_std_commands[CMD_MAX_COUNT] = {
 210         SCPI_CMD_SCPI_CAPABILITIES,
 211         SCPI_CMD_GET_CLOCK_INFO,
 212         SCPI_CMD_GET_CLOCK_VALUE,
 213         SCPI_CMD_SET_CLOCK_VALUE,
 214         SCPI_CMD_GET_DVFS,
 215         SCPI_CMD_SET_DVFS,
 216         SCPI_CMD_GET_DVFS_INFO,
 217         SCPI_CMD_SENSOR_CAPABILITIES,
 218         SCPI_CMD_SENSOR_INFO,
 219         SCPI_CMD_SENSOR_VALUE,
 220         SCPI_CMD_SET_DEVICE_PWR_STATE,
 221         SCPI_CMD_GET_DEVICE_PWR_STATE,
 222 };
 223
 224 static int scpi_legacy_commands[CMD_MAX_COUNT] = {
 225         LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
 226         -1, /* GET_CLOCK_INFO */
 227         LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
 228         LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
 229         LEGACY_SCPI_CMD_GET_DVFS,
 230         LEGACY_SCPI_CMD_SET_DVFS,
 231         LEGACY_SCPI_CMD_GET_DVFS_INFO,
 232         LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
 233         LEGACY_SCPI_CMD_SENSOR_INFO,
 234         LEGACY_SCPI_CMD_SENSOR_VALUE,
 235         -1, /* SET_DEVICE_PWR_STATE */
 236         -1, /* GET_DEVICE_PWR_STATE */
 237 };
 238
 239 struct scpi_xfer {
 240         u32 slot; /* has to be first element */
 241         u32 cmd;
 242         u32 status;
 243         const void *tx_buf;
 244         void *rx_buf;
 245         unsigned int tx_len;
 246         unsigned int rx_len;
 247         struct list_head node;
 248         struct completion done;
 249 };
 250
 251 struct scpi_chan {
 252         struct mbox_client cl;
 253         struct mbox_chan *chan;
 254         void __iomem *tx_payload;
 255         void __iomem *rx_payload;
 256         struct list_head rx_pending;
 257         struct list_head xfers_list;
 258         struct scpi_xfer *xfers;
 259         spinlock_t rx_lock; /* locking for the rx pending list */
 260         struct mutex xfers_lock;
 261         u8 token;
 262 };
 263
 264 struct scpi_drvinfo {
 265         u32 protocol_version;
 266         u32 firmware_version;
 267         bool is_legacy;
 268         int num_chans;
 269         int *commands;
 270         DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
 271         atomic_t next_chan;
 272         struct scpi_ops *scpi_ops;
 273         struct scpi_chan *channels;
 274         struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
 275 };
 276
 277 /*
 278  * The SCP firmware only executes in little-endian mode, so any buffers
 279  * shared through SCPI should have their contents converted to little-endian
 280  */
 281 struct scpi_shared_mem {
 282         __le32 command;
 283         __le32 status;
 284         u8 payload[0];
 285 } __packed;
 286
 287 struct legacy_scpi_shared_mem {
 288         __le32 status;
 289         u8 payload[0];
 290 } __packed;
 291
 292 struct scp_capabilities {
 293         __le32 protocol_version;
 294         __le32 event_version;
 295         __le32 platform_version;
 296         __le32 commands[4];
 297 } __packed;
 298
 299 struct clk_get_info {
 300         __le16 id;
 301         __le16 flags;
 302         __le32 min_rate;
 303         __le32 max_rate;
 304         u8 name[20];
 305 } __packed;
 306
 307 struct clk_set_value {
 308         __le16 id;
 309         __le16 reserved;
 310         __le32 rate;
 311 } __packed;
 312
 313 struct legacy_clk_set_value {
 314         __le32 rate;
 315         __le16 id;
 316         __le16 reserved;
 317 } __packed;
 318
 319 struct dvfs_info {
 320         u8 domain;
 321         u8 opp_count;
 322         __le16 latency;
 323         struct {
 324                 __le32 freq;
 325                 __le32 m_volt;
 326         } opps[MAX_DVFS_OPPS];
 327 } __packed;
 328
 329 struct dvfs_set {
 330         u8 domain;
 331         u8 index;
 332 } __packed;
 333
 334 struct sensor_capabilities {
 335         __le16 sensors;
 336 } __packed;
 337
 338 struct _scpi_sensor_info {
 339         __le16 sensor_id;
 340         u8 class;
 341         u8 trigger_type;
 342         char name[20];
 343 };
 344
 345 struct dev_pstate_set {
 346         __le16 dev_id;
 347         u8 pstate;
 348 } __packed;
 349
 350 static struct scpi_drvinfo *scpi_info;
 351
 352 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
 353         /* better than switch case as long as return value is continuous */
 354         0, /* SCPI_SUCCESS */
 355         -EINVAL, /* SCPI_ERR_PARAM */
 356         -ENOEXEC, /* SCPI_ERR_ALIGN */
 357         -EMSGSIZE, /* SCPI_ERR_SIZE */
 358         -EINVAL, /* SCPI_ERR_HANDLER */
 359         -EACCES, /* SCPI_ERR_ACCESS */
 360         -ERANGE, /* SCPI_ERR_RANGE */
 361         -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
 362         -ENOMEM, /* SCPI_ERR_NOMEM */
 363         -EINVAL, /* SCPI_ERR_PWRSTATE */
 364         -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
 365         -EIO, /* SCPI_ERR_DEVICE */
 366         -EBUSY, /* SCPI_ERR_BUSY */
 367 };
 368
 369 static inline int scpi_to_linux_errno(int errno)
 370 {
 371         if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
 372                 return scpi_linux_errmap[errno];
 373         return -EIO;
 374 }
 375
 376 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
 377 {
 378         unsigned long flags;
 379         struct scpi_xfer *t, *match = NULL;
 380
 381         spin_lock_irqsave(&ch->rx_lock, flags);
 382         if (list_empty(&ch->rx_pending)) {
 383                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 384                 return;
 385         }
 386
 387         /* Command type is not replied by the SCP Firmware in legacy Mode
 388          * We should consider that command is the head of pending RX commands
 389          * if the list is not empty. In TX only mode, the list would be empty.
 390          */
 391         if (scpi_info->is_legacy) {
 392                 match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
 393                                          node);
 394                 list_del(&match->node);
 395         } else {
 396                 list_for_each_entry(t, &ch->rx_pending, node)
 397                         if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
 398                                 list_del(&t->node);
 399                                 match = t;
 400                                 break;
 401                         }
 402         }
 403         /* check if wait_for_completion is in progress or timed-out */
 404         if (match && !completion_done(&match->done)) {
 405                 unsigned int len;
 406
 407                 if (scpi_info->is_legacy) {
 408                         struct legacy_scpi_shared_mem __iomem *mem =
 409                                                         ch->rx_payload;
 410
 411                         /* RX Length is not replied by the legacy Firmware */
 412                         len = match->rx_len;
 413
 414                         match->status = ioread32(&mem->status);
 415                         memcpy_fromio(match->rx_buf, mem->payload, len);
 416                 } else {
 417                         struct scpi_shared_mem __iomem *mem = ch->rx_payload;
 418
 419                         len = min(match->rx_len, CMD_SIZE(cmd));
 420
 421                         match->status = ioread32(&mem->status);
 422                         memcpy_fromio(match->rx_buf, mem->payload, len);
 423                 }
 424
 425                 if (match->rx_len > len)
 426                         memset(match->rx_buf + len, 0, match->rx_len - len);
 427                 complete(&match->done);
 428         }
 429         spin_unlock_irqrestore(&ch->rx_lock, flags);
 430 }
 431
 432 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
 433 {
 434         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 435         struct scpi_shared_mem __iomem *mem = ch->rx_payload;
 436         u32 cmd = 0;
 437
 438         if (!scpi_info->is_legacy)
 439                 cmd = ioread32(&mem->command);
 440
 441         scpi_process_cmd(ch, cmd);
 442 }
 443
 444 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
 445 {
 446         unsigned long flags;
 447         struct scpi_xfer *t = msg;
 448         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 449         struct scpi_shared_mem __iomem *mem = ch->tx_payload;
 450
 451         if (t->tx_buf) {
 452                 if (scpi_info->is_legacy)
 453                         memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
 454                 else
 455                         memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
 456         }
 457
 458         if (t->rx_buf) {
 459                 if (!(++ch->token))
 460                         ++ch->token;
 461                 ADD_SCPI_TOKEN(t->cmd, ch->token);
 462                 spin_lock_irqsave(&ch->rx_lock, flags);
 463                 list_add_tail(&t->node, &ch->rx_pending);
 464                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 465         }
 466
 467         if (!scpi_info->is_legacy)
 468                 iowrite32(t->cmd, &mem->command);
 469 }
 470
 471 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
 472 {
 473         struct scpi_xfer *t;
 474
 475         mutex_lock(&ch->xfers_lock);
 476         if (list_empty(&ch->xfers_list)) {
 477                 mutex_unlock(&ch->xfers_lock);
 478                 return NULL;
 479         }
 480         t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
 481         list_del(&t->node);
 482         mutex_unlock(&ch->xfers_lock);
 483         return t;
 484 }
 485
 486 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
 487 {
 488         mutex_lock(&ch->xfers_lock);
 489         list_add_tail(&t->node, &ch->xfers_list);
 490         mutex_unlock(&ch->xfers_lock);
 491 }
 492
 493 static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
 494                              void *rx_buf, unsigned int rx_len)
 495 {
 496         int ret;
 497         u8 chan;
 498         u8 cmd;
 499         struct scpi_xfer *msg;
 500         struct scpi_chan *scpi_chan;
 501
 502         if (scpi_info->commands[idx] < 0)
 503                 return -EOPNOTSUPP;
 504
 505         cmd = scpi_info->commands[idx];
 506
 507         if (scpi_info->is_legacy)
 508                 chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
 509         else
 510                 chan = atomic_inc_return(&scpi_info->next_chan) %
 511                         scpi_info->num_chans;
 512         scpi_chan = scpi_info->channels + chan;
 513
 514         msg = get_scpi_xfer(scpi_chan);
 515         if (!msg)
 516                 return -ENOMEM;
 517
 518         if (scpi_info->is_legacy) {
 519                 msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
 520                 msg->slot = msg->cmd;
 521         } else {
 522                 msg->slot = BIT(SCPI_SLOT);
 523                 msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
 524         }
 525         msg->tx_buf = tx_buf;
 526         msg->tx_len = tx_len;
 527         msg->rx_buf = rx_buf;
 528         msg->rx_len = rx_len;
 529         reinit_completion(&msg->done);
 530
 531         ret = mbox_send_message(scpi_chan->chan, msg);
 532         if (ret < 0 || !rx_buf)
 533                 goto out;
 534
 535         if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
 536                 ret = -ETIMEDOUT;
 537         else
 538                 /* first status word */
 539                 ret = msg->status;
 540 out:
 541         if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
 542                 scpi_process_cmd(scpi_chan, msg->cmd);
 543
 544         put_scpi_xfer(msg, scpi_chan);
 545         /* SCPI error codes > 0, translate them to Linux scale*/
 546         return ret > 0 ? scpi_to_linux_errno(ret) : ret;
 547 }
 548
 549 static u32 scpi_get_version(void)
 550 {
 551         return scpi_info->protocol_version;
 552 }
 553
 554 static int
 555 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
 556 {
 557         int ret;
 558         struct clk_get_info clk;
 559         __le16 le_clk_id = cpu_to_le16(clk_id);
 560
 561         ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
 562                                 sizeof(le_clk_id), &clk, sizeof(clk));
 563         if (!ret) {
 564                 *min = le32_to_cpu(clk.min_rate);
 565                 *max = le32_to_cpu(clk.max_rate);
 566         }
 567         return ret;
 568 }
 569
 570 static unsigned long scpi_clk_get_val(u16 clk_id)
 571 {
 572         int ret;
 573         __le32 rate;
 574         __le16 le_clk_id = cpu_to_le16(clk_id);
 575
 576         ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
 577                                 sizeof(le_clk_id), &rate, sizeof(rate));
 578
 579         return ret ? ret : le32_to_cpu(rate);
 580 }
 581
 582 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
 583 {
 584         int stat;
 585         struct 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
 594 static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
 595 {
 596         int stat;
 597         struct legacy_clk_set_value clk = {
 598                 .id = cpu_to_le16(clk_id),
 599                 .rate = cpu_to_le32(rate)
 600         };
 601
 602         return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 603                                  &stat, sizeof(stat));
 604 }
 605
 606 static int scpi_dvfs_get_idx(u8 domain)
 607 {
 608         int ret;
 609         u8 dvfs_idx;
 610
 611         ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
 612                                 &dvfs_idx, sizeof(dvfs_idx));
 613
 614         return ret ? ret : dvfs_idx;
 615 }
 616
 617 static int scpi_dvfs_set_idx(u8 domain, u8 index)
 618 {
 619         int stat;
 620         struct dvfs_set dvfs = {domain, index};
 621
 622         return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
 623                                  &stat, sizeof(stat));
 624 }
 625
 626 static int opp_cmp_func(const void *opp1, const void *opp2)
 627 {
 628         const struct scpi_opp *t1 = opp1, *t2 = opp2;
 629
 630         return t1->freq - t2->freq;
 631 }
 632
 633 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
 634 {
 635         if (domain >= MAX_DVFS_DOMAINS)
 636                 return ERR_PTR(-EINVAL);
 637
 638         return scpi_info->dvfs[domain] ?: ERR_PTR(-EINVAL);
 639 }
 640
 641 static int scpi_dvfs_populate_info(struct device *dev, u8 domain)
 642 {
 643         struct scpi_dvfs_info *info;
 644         struct scpi_opp *opp;
 645         struct dvfs_info buf;
 646         int ret, i;
 647
 648         ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
 649                                 &buf, sizeof(buf));
 650         if (ret)
 651                 return ret;
 652
 653         info = devm_kmalloc(dev, sizeof(*info), GFP_KERNEL);
 654         if (!info)
 655                 return -ENOMEM;
 656
 657         info->count = buf.opp_count;
 658         info->latency = le16_to_cpu(buf.latency) * 1000; /* uS to nS */
 659
 660         info->opps = devm_kcalloc(dev, info->count, sizeof(*opp), GFP_KERNEL);
 661         if (!info->opps)
 662                 return -ENOMEM;
 663
 664         for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
 665                 opp->freq = le32_to_cpu(buf.opps[i].freq);
 666                 opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
 667         }
 668
 669         sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
 670
 671         scpi_info->dvfs[domain] = info;
 672         return 0;
 673 }
 674
 675 static void scpi_dvfs_populate(struct device *dev)
 676 {
 677         int domain;
 678
 679         for (domain = 0; domain < MAX_DVFS_DOMAINS; domain++)
 680                 scpi_dvfs_populate_info(dev, domain);
 681 }
 682
 683 static int scpi_dev_domain_id(struct device *dev)
 684 {
 685         struct of_phandle_args clkspec;
 686
 687         if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
 688                                        0, &clkspec))
 689                 return -EINVAL;
 690
 691         return clkspec.args[0];
 692 }
 693
 694 static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
 695 {
 696         int domain = scpi_dev_domain_id(dev);
 697
 698         if (domain < 0)
 699                 return ERR_PTR(domain);
 700
 701         return scpi_dvfs_get_info(domain);
 702 }
 703
 704 static int scpi_dvfs_get_transition_latency(struct device *dev)
 705 {
 706         struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 707
 708         if (IS_ERR(info))
 709                 return PTR_ERR(info);
 710
 711         return info->latency;
 712 }
 713
 714 static int scpi_dvfs_add_opps_to_device(struct device *dev)
 715 {
 716         int idx, ret;
 717         struct scpi_opp *opp;
 718         struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 719
 720         if (IS_ERR(info))
 721                 return PTR_ERR(info);
 722
 723         if (!info->opps)
 724                 return -EIO;
 725
 726         for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
 727                 ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
 728                 if (ret) {
 729                         dev_warn(dev, "failed to add opp %uHz %umV\n",
 730                                  opp->freq, opp->m_volt);
 731                         while (idx-- > 0)
 732                                 dev_pm_opp_remove(dev, (--opp)->freq);
 733                         return ret;
 734                 }
 735         }
 736         return 0;
 737 }
 738
 739 static int scpi_sensor_get_capability(u16 *sensors)
 740 {
 741         struct sensor_capabilities cap_buf;
 742         int ret;
 743
 744         ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
 745                                 sizeof(cap_buf));
 746         if (!ret)
 747                 *sensors = le16_to_cpu(cap_buf.sensors);
 748
 749         return ret;
 750 }
 751
 752 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
 753 {
 754         __le16 id = cpu_to_le16(sensor_id);
 755         struct _scpi_sensor_info _info;
 756         int ret;
 757
 758         ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
 759                                 &_info, sizeof(_info));
 760         if (!ret) {
 761                 memcpy(info, &_info, sizeof(*info));
 762                 info->sensor_id = le16_to_cpu(_info.sensor_id);
 763         }
 764
 765         return ret;
 766 }
 767
 768 static int scpi_sensor_get_value(u16 sensor, u64 *val)
 769 {
 770         __le16 id = cpu_to_le16(sensor);
 771         __le64 value;
 772         int ret;
 773
 774         ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
 775                                 &value, sizeof(value));
 776         if (ret)
 777                 return ret;
 778
 779         if (scpi_info->is_legacy)
 780                 /* only 32-bits supported, upper 32 bits can be junk */
 781                 *val = le32_to_cpup((__le32 *)&value);
 782         else
 783                 *val = le64_to_cpu(value);
 784
 785         return 0;
 786 }
 787
 788 static int scpi_device_get_power_state(u16 dev_id)
 789 {
 790         int ret;
 791         u8 pstate;
 792         __le16 id = cpu_to_le16(dev_id);
 793
 794         ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
 795                                 sizeof(id), &pstate, sizeof(pstate));
 796         return ret ? ret : pstate;
 797 }
 798
 799 static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
 800 {
 801         int stat;
 802         struct dev_pstate_set dev_set = {
 803                 .dev_id = cpu_to_le16(dev_id),
 804                 .pstate = pstate,
 805         };
 806
 807         return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
 808                                  sizeof(dev_set), &stat, sizeof(stat));
 809 }
 810
 811 static struct scpi_ops scpi_ops = {
 812         .get_version = scpi_get_version,
 813         .clk_get_range = scpi_clk_get_range,
 814         .clk_get_val = scpi_clk_get_val,
 815         .clk_set_val = scpi_clk_set_val,
 816         .dvfs_get_idx = scpi_dvfs_get_idx,
 817         .dvfs_set_idx = scpi_dvfs_set_idx,
 818         .dvfs_get_info = scpi_dvfs_get_info,
 819         .device_domain_id = scpi_dev_domain_id,
 820         .get_transition_latency = scpi_dvfs_get_transition_latency,
 821         .add_opps_to_device = scpi_dvfs_add_opps_to_device,
 822         .sensor_get_capability = scpi_sensor_get_capability,
 823         .sensor_get_info = scpi_sensor_get_info,
 824         .sensor_get_value = scpi_sensor_get_value,
 825         .device_get_power_state = scpi_device_get_power_state,
 826         .device_set_power_state = scpi_device_set_power_state,
 827 };
 828
 829 struct scpi_ops *get_scpi_ops(void)
 830 {
 831         return scpi_info ? scpi_info->scpi_ops : NULL;
 832 }
 833 EXPORT_SYMBOL_GPL(get_scpi_ops);
 834
 835 static int scpi_init_versions(struct scpi_drvinfo *info)
 836 {
 837         int ret;
 838         struct scp_capabilities caps;
 839
 840         ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
 841                                 &caps, sizeof(caps));
 842         if (!ret) {
 843                 info->protocol_version = le32_to_cpu(caps.protocol_version);
 844                 info->firmware_version = le32_to_cpu(caps.platform_version);
 845         }
 846         /* Ignore error if not implemented */
 847         if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
 848                 return 0;
 849
 850         return ret;
 851 }
 852
 853 static ssize_t protocol_version_show(struct device *dev,
 854                                      struct device_attribute *attr, char *buf)
 855 {
 856         return sprintf(buf, "%lu.%lu\n",
 857                 FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
 858                 FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version));
 859 }
 860 static DEVICE_ATTR_RO(protocol_version);
 861
 862 static ssize_t firmware_version_show(struct device *dev,
 863                                      struct device_attribute *attr, char *buf)
 864 {
 865         return sprintf(buf, "%lu.%lu.%lu\n",
 866                      FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
 867                      FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
 868                      FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
 869 }
 870 static DEVICE_ATTR_RO(firmware_version);
 871
 872 static struct attribute *versions_attrs[] = {
 873         &dev_attr_firmware_version.attr,
 874         &dev_attr_protocol_version.attr,
 875         NULL,
 876 };
 877 ATTRIBUTE_GROUPS(versions);
 878
 879 static void scpi_free_channels(void *data)
 880 {
 881         struct scpi_drvinfo *info = data;
 882         int i;
 883
 884         for (i = 0; i < info->num_chans; i++)
 885                 mbox_free_channel(info->channels[i].chan);
 886 }
 887
 888 #define MAX_SCPI_XFERS          10
 889 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
 890 {
 891         int i;
 892         struct scpi_xfer *xfers;
 893
 894         xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
 895         if (!xfers)
 896                 return -ENOMEM;
 897
 898         ch->xfers = xfers;
 899         for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
 900                 init_completion(&xfers->done);
 901                 list_add_tail(&xfers->node, &ch->xfers_list);
 902         }
 903
 904         return 0;
 905 }
 906
 907 static const struct of_device_id legacy_scpi_of_match[] = {
 908         {.compatible = "arm,scpi-pre-1.0"},
 909         {},
 910 };
 911
 912 static int scpi_probe(struct platform_device *pdev)
 913 {
 914         int count, idx, ret;
 915         struct resource res;
 916         struct device *dev = &pdev->dev;
 917         struct device_node *np = dev->of_node;
 918
 919         scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
 920         if (!scpi_info)
 921                 return -ENOMEM;
 922
 923         if (of_match_device(legacy_scpi_of_match, &pdev->dev))
 924                 scpi_info->is_legacy = true;
 925
 926         count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 927         if (count < 0) {
 928                 dev_err(dev, "no mboxes property in '%pOF'\n", np);
 929                 return -ENODEV;
 930         }
 931
 932         scpi_info->channels = devm_kcalloc(dev, count, sizeof(struct scpi_chan),
 933                                            GFP_KERNEL);
 934         if (!scpi_info->channels)
 935                 return -ENOMEM;
 936
 937         ret = devm_add_action(dev, scpi_free_channels, scpi_info);
 938         if (ret)
 939                 return ret;
 940
 941         for (; scpi_info->num_chans < count; scpi_info->num_chans++) {
 942                 resource_size_t size;
 943                 int idx = scpi_info->num_chans;
 944                 struct scpi_chan *pchan = scpi_info->channels + idx;
 945                 struct mbox_client *cl = &pchan->cl;
 946                 struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 947
 948                 ret = of_address_to_resource(shmem, 0, &res);
 949                 of_node_put(shmem);
 950                 if (ret) {
 951                         dev_err(dev, "failed to get SCPI payload mem resource\n");
 952                         return ret;
 953                 }
 954
 955                 size = resource_size(&res);
 956                 pchan->rx_payload = devm_ioremap(dev, res.start, size);
 957                 if (!pchan->rx_payload) {
 958                         dev_err(dev, "failed to ioremap SCPI payload\n");
 959                         return -EADDRNOTAVAIL;
 960                 }
 961                 pchan->tx_payload = pchan->rx_payload + (size >> 1);
 962
 963                 cl->dev = dev;
 964                 cl->rx_callback = scpi_handle_remote_msg;
 965                 cl->tx_prepare = scpi_tx_prepare;
 966                 cl->tx_block = true;
 967                 cl->tx_tout = 20;
 968                 cl->knows_txdone = false; /* controller can't ack */
 969
 970                 INIT_LIST_HEAD(&pchan->rx_pending);
 971                 INIT_LIST_HEAD(&pchan->xfers_list);
 972                 spin_lock_init(&pchan->rx_lock);
 973                 mutex_init(&pchan->xfers_lock);
 974
 975                 ret = scpi_alloc_xfer_list(dev, pchan);
 976                 if (!ret) {
 977                         pchan->chan = mbox_request_channel(cl, idx);
 978                         if (!IS_ERR(pchan->chan))
 979                                 continue;
 980                         ret = PTR_ERR(pchan->chan);
 981                         if (ret != -EPROBE_DEFER)
 982                                 dev_err(dev, "failed to get channel%d err %d\n",
 983                                         idx, ret);
 984                 }
 985                 return ret;
 986         }
 987
 988         scpi_info->commands = scpi_std_commands;
 989         scpi_info->scpi_ops = &scpi_ops;
 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         scpi_dvfs_populate(dev);
1009
1010         _dev_info(dev, "SCP Protocol %lu.%lu Firmware %lu.%lu.%lu version\n",
1011                   FIELD_GET(PROTO_REV_MAJOR_MASK, scpi_info->protocol_version),
1012                   FIELD_GET(PROTO_REV_MINOR_MASK, scpi_info->protocol_version),
1013                   FIELD_GET(FW_REV_MAJOR_MASK, scpi_info->firmware_version),
1014                   FIELD_GET(FW_REV_MINOR_MASK, scpi_info->firmware_version),
1015                   FIELD_GET(FW_REV_PATCH_MASK, scpi_info->firmware_version));
1016
1017         ret = devm_device_add_groups(dev, versions_groups);
1018         if (ret)
1019                 dev_err(dev, "unable to create sysfs version group\n");
1020
1021         return devm_of_platform_populate(dev);
1022 }
1023
1024 static const struct of_device_id scpi_of_match[] = {
1025         {.compatible = "arm,scpi"},
1026         {.compatible = "arm,scpi-pre-1.0"},
1027         {},
1028 };
1029
1030 MODULE_DEVICE_TABLE(of, scpi_of_match);
1031
1032 static struct platform_driver scpi_driver = {
1033         .driver = {
1034                 .name = "scpi_protocol",
1035                 .of_match_table = scpi_of_match,
1036         },
1037         .probe = scpi_probe,
1038 };
1039 module_platform_driver(scpi_driver);
1040
1041 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1042 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1043 MODULE_LICENSE("GPL v2");