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_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
  78 enum 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 */
  96 enum 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 */
 130 enum 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 */
 167 static 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 */
 185 enum 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
 201 static 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
 216 static 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
 231 struct 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
 243 struct 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
 256 struct 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  */
 273 struct scpi_shared_mem {
 274         __le32 command;
 275         __le32 status;
 276         u8 payload[0];
 277 } __packed;
 278
 279 struct legacy_scpi_shared_mem {
 280         __le32 status;
 281         u8 payload[0];
 282 } __packed;
 283
 284 struct scp_capabilities {
 285         __le32 protocol_version;
 286         __le32 event_version;
 287         __le32 platform_version;
 288         __le32 commands[4];
 289 } __packed;
 290
 291 struct clk_get_info {
 292         __le16 id;
 293         __le16 flags;
 294         __le32 min_rate;
 295         __le32 max_rate;
 296         u8 name[20];
 297 } __packed;
 298
 299 struct clk_set_value {
 300         __le16 id;
 301         __le16 reserved;
 302         __le32 rate;
 303 } __packed;
 304
 305 struct legacy_clk_set_value {
 306         __le32 rate;
 307         __le16 id;
 308         __le16 reserved;
 309 } __packed;
 310
 311 struct 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
 321 struct dvfs_set {
 322         u8 domain;
 323         u8 index;
 324 } __packed;
 325
 326 struct _scpi_sensor_info {
 327         __le16 sensor_id;
 328         u8 class;
 329         u8 trigger_type;
 330         char name[20];
 331 };
 332
 333 struct dev_pstate_set {
 334         __le16 dev_id;
 335         u8 pstate;
 336 } __packed;
 337
 338 static struct scpi_drvinfo *scpi_info;
 339
 340 static 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
 357 static 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
 364 static 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
 420 static 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
 432 static 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
 459 static 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
 474 static 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
 481 static 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;
 528 out:
 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
 537 static u32 scpi_get_version(void)
 538 {
 539         return scpi_info->protocol_version;
 540 }
 541
 542 static int
 543 scpi_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
 558 static 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
 570 static 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
 582 static 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
 594 static 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
 605 static 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
 614 static 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
 621 static 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
 663 static 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
 674 static 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
 684 static 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
 694 static 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
 719 static 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
 732 static 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
 748 static 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
 768 static 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
 779 static 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
 791 static 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
 809 struct scpi_ops *get_scpi_ops(void)
 810 {
 811         return scpi_info ? scpi_info->scpi_ops : NULL;
 812 }
 813 EXPORT_SYMBOL_GPL(get_scpi_ops);
 814
 815 static 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
 833 static 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 }
 842 static DEVICE_ATTR_RO(protocol_version);
 843
 844 static 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 }
 854 static DEVICE_ATTR_RO(firmware_version);
 855
 856 static struct attribute *versions_attrs[] = {
 857         &dev_attr_firmware_version.attr,
 858         &dev_attr_protocol_version.attr,
 859         NULL,
 860 };
 861 ATTRIBUTE_GROUPS(versions);
 862
 863 static 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
 872 static 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
 888 static 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_kcalloc(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
 906 static const struct of_device_id legacy_scpi_of_match[] = {
 907         {.compatible = "arm,scpi-pre-1.0"},
 908         {},
 909 };
 910
 911 static 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
1032 static const struct of_device_id scpi_of_match[] = {
1033         {.compatible = "arm,scpi"},
1034         {.compatible = "arm,scpi-pre-1.0"},
1035         {},
1036 };
1037
1038 MODULE_DEVICE_TABLE(of, scpi_of_match);
1039
1040 static 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 };
1048 module_platform_driver(scpi_driver);
1049
1050 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1051 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1052 MODULE_LICENSE("GPL v2");