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/device.h>
  32 #include <linux/err.h>
  33 #include <linux/export.h>
  34 #include <linux/io.h>
  35 #include <linux/kernel.h>
  36 #include <linux/list.h>
  37 #include <linux/mailbox_client.h>
  38 #include <linux/module.h>
  39 #include <linux/of_address.h>
  40 #include <linux/of_platform.h>
  41 #include <linux/printk.h>
  42 #include <linux/pm_opp.h>
  43 #include <linux/scpi_protocol.h>
  44 #include <linux/slab.h>
  45 #include <linux/sort.h>
  46 #include <linux/spinlock.h>
  47
  48 #define CMD_ID_SHIFT            0
  49 #define CMD_ID_MASK             0x7f
  50 #define CMD_TOKEN_ID_SHIFT      8
  51 #define CMD_TOKEN_ID_MASK       0xff
  52 #define CMD_DATA_SIZE_SHIFT     16
  53 #define CMD_DATA_SIZE_MASK      0x1ff
  54 #define CMD_LEGACY_DATA_SIZE_SHIFT      20
  55 #define CMD_LEGACY_DATA_SIZE_MASK       0x1ff
  56 #define PACK_SCPI_CMD(cmd_id, tx_sz)                    \
  57         ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |   \
  58         (((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
  59 #define ADD_SCPI_TOKEN(cmd, token)                      \
  60         ((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
  61 #define PACK_LEGACY_SCPI_CMD(cmd_id, tx_sz)                             \
  62         ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |                          \
  63         (((tx_sz) & CMD_LEGACY_DATA_SIZE_MASK) << CMD_LEGACY_DATA_SIZE_SHIFT))
  64
  65 #define CMD_SIZE(cmd)   (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
  66 #define CMD_LEGACY_SIZE(cmd)    (((cmd) >> CMD_LEGACY_DATA_SIZE_SHIFT) & \
  67                                         CMD_LEGACY_DATA_SIZE_MASK)
  68 #define CMD_UNIQ_MASK   (CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
  69 #define CMD_XTRACT_UNIQ(cmd)    ((cmd) & CMD_UNIQ_MASK)
  70
  71 #define SCPI_SLOT               0
  72
  73 #define MAX_DVFS_DOMAINS        8
  74 #define MAX_DVFS_OPPS           16
  75 #define DVFS_LATENCY(hdr)       (le32_to_cpu(hdr) >> 16)
  76 #define DVFS_OPP_COUNT(hdr)     ((le32_to_cpu(hdr) >> 8) & 0xff)
  77
  78 #define PROTOCOL_REV_MINOR_BITS 16
  79 #define PROTOCOL_REV_MINOR_MASK ((1U << PROTOCOL_REV_MINOR_BITS) - 1)
  80 #define PROTOCOL_REV_MAJOR(x)   ((x) >> PROTOCOL_REV_MINOR_BITS)
  81 #define PROTOCOL_REV_MINOR(x)   ((x) & PROTOCOL_REV_MINOR_MASK)
  82
  83 #define FW_REV_MAJOR_BITS       24
  84 #define FW_REV_MINOR_BITS       16
  85 #define FW_REV_PATCH_MASK       ((1U << FW_REV_MINOR_BITS) - 1)
  86 #define FW_REV_MINOR_MASK       ((1U << FW_REV_MAJOR_BITS) - 1)
  87 #define FW_REV_MAJOR(x)         ((x) >> FW_REV_MAJOR_BITS)
  88 #define FW_REV_MINOR(x)         (((x) & FW_REV_MINOR_MASK) >> FW_REV_MINOR_BITS)
  89 #define FW_REV_PATCH(x)         ((x) & FW_REV_PATCH_MASK)
  90
  91 #define MAX_RX_TIMEOUT          (msecs_to_jiffies(30))
  92
  93 enum scpi_error_codes {
  94         SCPI_SUCCESS = 0, /* Success */
  95         SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
  96         SCPI_ERR_ALIGN = 2, /* Invalid alignment */
  97         SCPI_ERR_SIZE = 3, /* Invalid size */
  98         SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
  99         SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
 100         SCPI_ERR_RANGE = 6, /* Value out of range */
 101         SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
 102         SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
 103         SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
 104         SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
 105         SCPI_ERR_DEVICE = 11, /* Device error */
 106         SCPI_ERR_BUSY = 12, /* Device busy */
 107         SCPI_ERR_MAX
 108 };
 109
 110 /* SCPI Standard commands */
 111 enum scpi_std_cmd {
 112         SCPI_CMD_INVALID                = 0x00,
 113         SCPI_CMD_SCPI_READY             = 0x01,
 114         SCPI_CMD_SCPI_CAPABILITIES      = 0x02,
 115         SCPI_CMD_SET_CSS_PWR_STATE      = 0x03,
 116         SCPI_CMD_GET_CSS_PWR_STATE      = 0x04,
 117         SCPI_CMD_SET_SYS_PWR_STATE      = 0x05,
 118         SCPI_CMD_SET_CPU_TIMER          = 0x06,
 119         SCPI_CMD_CANCEL_CPU_TIMER       = 0x07,
 120         SCPI_CMD_DVFS_CAPABILITIES      = 0x08,
 121         SCPI_CMD_GET_DVFS_INFO          = 0x09,
 122         SCPI_CMD_SET_DVFS               = 0x0a,
 123         SCPI_CMD_GET_DVFS               = 0x0b,
 124         SCPI_CMD_GET_DVFS_STAT          = 0x0c,
 125         SCPI_CMD_CLOCK_CAPABILITIES     = 0x0d,
 126         SCPI_CMD_GET_CLOCK_INFO         = 0x0e,
 127         SCPI_CMD_SET_CLOCK_VALUE        = 0x0f,
 128         SCPI_CMD_GET_CLOCK_VALUE        = 0x10,
 129         SCPI_CMD_PSU_CAPABILITIES       = 0x11,
 130         SCPI_CMD_GET_PSU_INFO           = 0x12,
 131         SCPI_CMD_SET_PSU                = 0x13,
 132         SCPI_CMD_GET_PSU                = 0x14,
 133         SCPI_CMD_SENSOR_CAPABILITIES    = 0x15,
 134         SCPI_CMD_SENSOR_INFO            = 0x16,
 135         SCPI_CMD_SENSOR_VALUE           = 0x17,
 136         SCPI_CMD_SENSOR_CFG_PERIODIC    = 0x18,
 137         SCPI_CMD_SENSOR_CFG_BOUNDS      = 0x19,
 138         SCPI_CMD_SENSOR_ASYNC_VALUE     = 0x1a,
 139         SCPI_CMD_SET_DEVICE_PWR_STATE   = 0x1b,
 140         SCPI_CMD_GET_DEVICE_PWR_STATE   = 0x1c,
 141         SCPI_CMD_COUNT
 142 };
 143
 144 /* SCPI Legacy Commands */
 145 enum legacy_scpi_std_cmd {
 146         LEGACY_SCPI_CMD_INVALID                 = 0x00,
 147         LEGACY_SCPI_CMD_SCPI_READY              = 0x01,
 148         LEGACY_SCPI_CMD_SCPI_CAPABILITIES       = 0x02,
 149         LEGACY_SCPI_CMD_EVENT                   = 0x03,
 150         LEGACY_SCPI_CMD_SET_CSS_PWR_STATE       = 0x04,
 151         LEGACY_SCPI_CMD_GET_CSS_PWR_STATE       = 0x05,
 152         LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT      = 0x06,
 153         LEGACY_SCPI_CMD_GET_PWR_STATE_STAT      = 0x07,
 154         LEGACY_SCPI_CMD_SYS_PWR_STATE           = 0x08,
 155         LEGACY_SCPI_CMD_L2_READY                = 0x09,
 156         LEGACY_SCPI_CMD_SET_AP_TIMER            = 0x0a,
 157         LEGACY_SCPI_CMD_CANCEL_AP_TIME          = 0x0b,
 158         LEGACY_SCPI_CMD_DVFS_CAPABILITIES       = 0x0c,
 159         LEGACY_SCPI_CMD_GET_DVFS_INFO           = 0x0d,
 160         LEGACY_SCPI_CMD_SET_DVFS                = 0x0e,
 161         LEGACY_SCPI_CMD_GET_DVFS                = 0x0f,
 162         LEGACY_SCPI_CMD_GET_DVFS_STAT           = 0x10,
 163         LEGACY_SCPI_CMD_SET_RTC                 = 0x11,
 164         LEGACY_SCPI_CMD_GET_RTC                 = 0x12,
 165         LEGACY_SCPI_CMD_CLOCK_CAPABILITIES      = 0x13,
 166         LEGACY_SCPI_CMD_SET_CLOCK_INDEX         = 0x14,
 167         LEGACY_SCPI_CMD_SET_CLOCK_VALUE         = 0x15,
 168         LEGACY_SCPI_CMD_GET_CLOCK_VALUE         = 0x16,
 169         LEGACY_SCPI_CMD_PSU_CAPABILITIES        = 0x17,
 170         LEGACY_SCPI_CMD_SET_PSU                 = 0x18,
 171         LEGACY_SCPI_CMD_GET_PSU                 = 0x19,
 172         LEGACY_SCPI_CMD_SENSOR_CAPABILITIES     = 0x1a,
 173         LEGACY_SCPI_CMD_SENSOR_INFO             = 0x1b,
 174         LEGACY_SCPI_CMD_SENSOR_VALUE            = 0x1c,
 175         LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC     = 0x1d,
 176         LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS       = 0x1e,
 177         LEGACY_SCPI_CMD_SENSOR_ASYNC_VALUE      = 0x1f,
 178         LEGACY_SCPI_CMD_COUNT
 179 };
 180
 181 /* List all commands that are required to go through the high priority link */
 182 static int legacy_hpriority_cmds[] = {
 183         LEGACY_SCPI_CMD_GET_CSS_PWR_STATE,
 184         LEGACY_SCPI_CMD_CFG_PWR_STATE_STAT,
 185         LEGACY_SCPI_CMD_GET_PWR_STATE_STAT,
 186         LEGACY_SCPI_CMD_SET_DVFS,
 187         LEGACY_SCPI_CMD_GET_DVFS,
 188         LEGACY_SCPI_CMD_SET_RTC,
 189         LEGACY_SCPI_CMD_GET_RTC,
 190         LEGACY_SCPI_CMD_SET_CLOCK_INDEX,
 191         LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
 192         LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
 193         LEGACY_SCPI_CMD_SET_PSU,
 194         LEGACY_SCPI_CMD_GET_PSU,
 195         LEGACY_SCPI_CMD_SENSOR_CFG_PERIODIC,
 196         LEGACY_SCPI_CMD_SENSOR_CFG_BOUNDS,
 197 };
 198
 199 /* List all commands used by this driver, used as indexes */
 200 enum scpi_drv_cmds {
 201         CMD_SCPI_CAPABILITIES = 0,
 202         CMD_GET_CLOCK_INFO,
 203         CMD_GET_CLOCK_VALUE,
 204         CMD_SET_CLOCK_VALUE,
 205         CMD_GET_DVFS,
 206         CMD_SET_DVFS,
 207         CMD_GET_DVFS_INFO,
 208         CMD_SENSOR_CAPABILITIES,
 209         CMD_SENSOR_INFO,
 210         CMD_SENSOR_VALUE,
 211         CMD_SET_DEVICE_PWR_STATE,
 212         CMD_GET_DEVICE_PWR_STATE,
 213         CMD_MAX_COUNT,
 214 };
 215
 216 static int scpi_std_commands[CMD_MAX_COUNT] = {
 217         SCPI_CMD_SCPI_CAPABILITIES,
 218         SCPI_CMD_GET_CLOCK_INFO,
 219         SCPI_CMD_GET_CLOCK_VALUE,
 220         SCPI_CMD_SET_CLOCK_VALUE,
 221         SCPI_CMD_GET_DVFS,
 222         SCPI_CMD_SET_DVFS,
 223         SCPI_CMD_GET_DVFS_INFO,
 224         SCPI_CMD_SENSOR_CAPABILITIES,
 225         SCPI_CMD_SENSOR_INFO,
 226         SCPI_CMD_SENSOR_VALUE,
 227         SCPI_CMD_SET_DEVICE_PWR_STATE,
 228         SCPI_CMD_GET_DEVICE_PWR_STATE,
 229 };
 230
 231 static int scpi_legacy_commands[CMD_MAX_COUNT] = {
 232         LEGACY_SCPI_CMD_SCPI_CAPABILITIES,
 233         -1, /* GET_CLOCK_INFO */
 234         LEGACY_SCPI_CMD_GET_CLOCK_VALUE,
 235         LEGACY_SCPI_CMD_SET_CLOCK_VALUE,
 236         LEGACY_SCPI_CMD_GET_DVFS,
 237         LEGACY_SCPI_CMD_SET_DVFS,
 238         LEGACY_SCPI_CMD_GET_DVFS_INFO,
 239         LEGACY_SCPI_CMD_SENSOR_CAPABILITIES,
 240         LEGACY_SCPI_CMD_SENSOR_INFO,
 241         LEGACY_SCPI_CMD_SENSOR_VALUE,
 242         -1, /* SET_DEVICE_PWR_STATE */
 243         -1, /* GET_DEVICE_PWR_STATE */
 244 };
 245
 246 struct scpi_xfer {
 247         u32 slot; /* has to be first element */
 248         u32 cmd;
 249         u32 status;
 250         const void *tx_buf;
 251         void *rx_buf;
 252         unsigned int tx_len;
 253         unsigned int rx_len;
 254         struct list_head node;
 255         struct completion done;
 256 };
 257
 258 struct scpi_chan {
 259         struct mbox_client cl;
 260         struct mbox_chan *chan;
 261         void __iomem *tx_payload;
 262         void __iomem *rx_payload;
 263         struct list_head rx_pending;
 264         struct list_head xfers_list;
 265         struct scpi_xfer *xfers;
 266         spinlock_t rx_lock; /* locking for the rx pending list */
 267         struct mutex xfers_lock;
 268         u8 token;
 269 };
 270
 271 struct scpi_drvinfo {
 272         u32 protocol_version;
 273         u32 firmware_version;
 274         bool is_legacy;
 275         int num_chans;
 276         int *commands;
 277         DECLARE_BITMAP(cmd_priority, LEGACY_SCPI_CMD_COUNT);
 278         atomic_t next_chan;
 279         struct scpi_ops *scpi_ops;
 280         struct scpi_chan *channels;
 281         struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
 282 };
 283
 284 /*
 285  * The SCP firmware only executes in little-endian mode, so any buffers
 286  * shared through SCPI should have their contents converted to little-endian
 287  */
 288 struct scpi_shared_mem {
 289         __le32 command;
 290         __le32 status;
 291         u8 payload[0];
 292 } __packed;
 293
 294 struct legacy_scpi_shared_mem {
 295         __le32 status;
 296         u8 payload[0];
 297 } __packed;
 298
 299 struct scp_capabilities {
 300         __le32 protocol_version;
 301         __le32 event_version;
 302         __le32 platform_version;
 303         __le32 commands[4];
 304 } __packed;
 305
 306 struct clk_get_info {
 307         __le16 id;
 308         __le16 flags;
 309         __le32 min_rate;
 310         __le32 max_rate;
 311         u8 name[20];
 312 } __packed;
 313
 314 struct clk_get_value {
 315         __le32 rate;
 316 } __packed;
 317
 318 struct clk_set_value {
 319         __le16 id;
 320         __le16 reserved;
 321         __le32 rate;
 322 } __packed;
 323
 324 struct legacy_clk_set_value {
 325         __le32 rate;
 326         __le16 id;
 327         __le16 reserved;
 328 } __packed;
 329
 330 struct dvfs_info {
 331         __le32 header;
 332         struct {
 333                 __le32 freq;
 334                 __le32 m_volt;
 335         } opps[MAX_DVFS_OPPS];
 336 } __packed;
 337
 338 struct dvfs_set {
 339         u8 domain;
 340         u8 index;
 341 } __packed;
 342
 343 struct sensor_capabilities {
 344         __le16 sensors;
 345 } __packed;
 346
 347 struct _scpi_sensor_info {
 348         __le16 sensor_id;
 349         u8 class;
 350         u8 trigger_type;
 351         char name[20];
 352 };
 353
 354 struct sensor_value {
 355         __le32 lo_val;
 356         __le32 hi_val;
 357 } __packed;
 358
 359 struct dev_pstate_set {
 360         u16 dev_id;
 361         u8 pstate;
 362 } __packed;
 363
 364 static struct scpi_drvinfo *scpi_info;
 365
 366 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
 367         /* better than switch case as long as return value is continuous */
 368         0, /* SCPI_SUCCESS */
 369         -EINVAL, /* SCPI_ERR_PARAM */
 370         -ENOEXEC, /* SCPI_ERR_ALIGN */
 371         -EMSGSIZE, /* SCPI_ERR_SIZE */
 372         -EINVAL, /* SCPI_ERR_HANDLER */
 373         -EACCES, /* SCPI_ERR_ACCESS */
 374         -ERANGE, /* SCPI_ERR_RANGE */
 375         -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
 376         -ENOMEM, /* SCPI_ERR_NOMEM */
 377         -EINVAL, /* SCPI_ERR_PWRSTATE */
 378         -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
 379         -EIO, /* SCPI_ERR_DEVICE */
 380         -EBUSY, /* SCPI_ERR_BUSY */
 381 };
 382
 383 static inline int scpi_to_linux_errno(int errno)
 384 {
 385         if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
 386                 return scpi_linux_errmap[errno];
 387         return -EIO;
 388 }
 389
 390 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
 391 {
 392         unsigned long flags;
 393         struct scpi_xfer *t, *match = NULL;
 394
 395         spin_lock_irqsave(&ch->rx_lock, flags);
 396         if (list_empty(&ch->rx_pending)) {
 397                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 398                 return;
 399         }
 400
 401         /* Command type is not replied by the SCP Firmware in legacy Mode
 402          * We should consider that command is the head of pending RX commands
 403          * if the list is not empty. In TX only mode, the list would be empty.
 404          */
 405         if (scpi_info->is_legacy) {
 406                 match = list_first_entry(&ch->rx_pending, struct scpi_xfer,
 407                                          node);
 408                 list_del(&match->node);
 409         } else {
 410                 list_for_each_entry(t, &ch->rx_pending, node)
 411                         if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
 412                                 list_del(&t->node);
 413                                 match = t;
 414                                 break;
 415                         }
 416         }
 417         /* check if wait_for_completion is in progress or timed-out */
 418         if (match && !completion_done(&match->done)) {
 419                 unsigned int len;
 420
 421                 if (scpi_info->is_legacy) {
 422                         struct legacy_scpi_shared_mem *mem = ch->rx_payload;
 423
 424                         /* RX Length is not replied by the legacy Firmware */
 425                         len = match->rx_len;
 426
 427                         match->status = le32_to_cpu(mem->status);
 428                         memcpy_fromio(match->rx_buf, mem->payload, len);
 429                 } else {
 430                         struct scpi_shared_mem *mem = ch->rx_payload;
 431
 432                         len = min(match->rx_len, CMD_SIZE(cmd));
 433
 434                         match->status = le32_to_cpu(mem->status);
 435                         memcpy_fromio(match->rx_buf, mem->payload, len);
 436                 }
 437
 438                 if (match->rx_len > len)
 439                         memset(match->rx_buf + len, 0, match->rx_len - len);
 440                 complete(&match->done);
 441         }
 442         spin_unlock_irqrestore(&ch->rx_lock, flags);
 443 }
 444
 445 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
 446 {
 447         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 448         struct scpi_shared_mem *mem = ch->rx_payload;
 449         u32 cmd = 0;
 450
 451         if (!scpi_info->is_legacy)
 452                 cmd = le32_to_cpu(mem->command);
 453
 454         scpi_process_cmd(ch, cmd);
 455 }
 456
 457 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
 458 {
 459         unsigned long flags;
 460         struct scpi_xfer *t = msg;
 461         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 462         struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
 463
 464         if (t->tx_buf) {
 465                 if (scpi_info->is_legacy)
 466                         memcpy_toio(ch->tx_payload, t->tx_buf, t->tx_len);
 467                 else
 468                         memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
 469         }
 470
 471         if (t->rx_buf) {
 472                 if (!(++ch->token))
 473                         ++ch->token;
 474                 ADD_SCPI_TOKEN(t->cmd, ch->token);
 475                 spin_lock_irqsave(&ch->rx_lock, flags);
 476                 list_add_tail(&t->node, &ch->rx_pending);
 477                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 478         }
 479
 480         if (!scpi_info->is_legacy)
 481                 mem->command = cpu_to_le32(t->cmd);
 482 }
 483
 484 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
 485 {
 486         struct scpi_xfer *t;
 487
 488         mutex_lock(&ch->xfers_lock);
 489         if (list_empty(&ch->xfers_list)) {
 490                 mutex_unlock(&ch->xfers_lock);
 491                 return NULL;
 492         }
 493         t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
 494         list_del(&t->node);
 495         mutex_unlock(&ch->xfers_lock);
 496         return t;
 497 }
 498
 499 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
 500 {
 501         mutex_lock(&ch->xfers_lock);
 502         list_add_tail(&t->node, &ch->xfers_list);
 503         mutex_unlock(&ch->xfers_lock);
 504 }
 505
 506 static int scpi_send_message(u8 idx, void *tx_buf, unsigned int tx_len,
 507                              void *rx_buf, unsigned int rx_len)
 508 {
 509         int ret;
 510         u8 chan;
 511         u8 cmd;
 512         struct scpi_xfer *msg;
 513         struct scpi_chan *scpi_chan;
 514
 515         if (scpi_info->commands[idx] < 0)
 516                 return -EOPNOTSUPP;
 517
 518         cmd = scpi_info->commands[idx];
 519
 520         if (scpi_info->is_legacy)
 521                 chan = test_bit(cmd, scpi_info->cmd_priority) ? 1 : 0;
 522         else
 523                 chan = atomic_inc_return(&scpi_info->next_chan) %
 524                         scpi_info->num_chans;
 525         scpi_chan = scpi_info->channels + chan;
 526
 527         msg = get_scpi_xfer(scpi_chan);
 528         if (!msg)
 529                 return -ENOMEM;
 530
 531         if (scpi_info->is_legacy) {
 532                 msg->cmd = PACK_LEGACY_SCPI_CMD(cmd, tx_len);
 533                 msg->slot = msg->cmd;
 534         } else {
 535                 msg->slot = BIT(SCPI_SLOT);
 536                 msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
 537         }
 538         msg->tx_buf = tx_buf;
 539         msg->tx_len = tx_len;
 540         msg->rx_buf = rx_buf;
 541         msg->rx_len = rx_len;
 542         reinit_completion(&msg->done);
 543
 544         ret = mbox_send_message(scpi_chan->chan, msg);
 545         if (ret < 0 || !rx_buf)
 546                 goto out;
 547
 548         if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
 549                 ret = -ETIMEDOUT;
 550         else
 551                 /* first status word */
 552                 ret = msg->status;
 553 out:
 554         if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
 555                 scpi_process_cmd(scpi_chan, msg->cmd);
 556
 557         put_scpi_xfer(msg, scpi_chan);
 558         /* SCPI error codes > 0, translate them to Linux scale*/
 559         return ret > 0 ? scpi_to_linux_errno(ret) : ret;
 560 }
 561
 562 static u32 scpi_get_version(void)
 563 {
 564         return scpi_info->protocol_version;
 565 }
 566
 567 static int
 568 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
 569 {
 570         int ret;
 571         struct clk_get_info clk;
 572         __le16 le_clk_id = cpu_to_le16(clk_id);
 573
 574         ret = scpi_send_message(CMD_GET_CLOCK_INFO, &le_clk_id,
 575                                 sizeof(le_clk_id), &clk, sizeof(clk));
 576         if (!ret) {
 577                 *min = le32_to_cpu(clk.min_rate);
 578                 *max = le32_to_cpu(clk.max_rate);
 579         }
 580         return ret;
 581 }
 582
 583 static unsigned long scpi_clk_get_val(u16 clk_id)
 584 {
 585         int ret;
 586         struct clk_get_value clk;
 587         __le16 le_clk_id = cpu_to_le16(clk_id);
 588
 589         ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,
 590                                 sizeof(le_clk_id), &clk, sizeof(clk));
 591
 592         return ret ? ret : le32_to_cpu(clk.rate);
 593 }
 594
 595 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
 596 {
 597         int stat;
 598         struct clk_set_value clk = {
 599                 .id = cpu_to_le16(clk_id),
 600                 .rate = cpu_to_le32(rate)
 601         };
 602
 603         return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 604                                  &stat, sizeof(stat));
 605 }
 606
 607 static int legacy_scpi_clk_set_val(u16 clk_id, unsigned long rate)
 608 {
 609         int stat;
 610         struct legacy_clk_set_value clk = {
 611                 .id = cpu_to_le16(clk_id),
 612                 .rate = cpu_to_le32(rate)
 613         };
 614
 615         return scpi_send_message(CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 616                                  &stat, sizeof(stat));
 617 }
 618
 619 static int scpi_dvfs_get_idx(u8 domain)
 620 {
 621         int ret;
 622         u8 dvfs_idx;
 623
 624         ret = scpi_send_message(CMD_GET_DVFS, &domain, sizeof(domain),
 625                                 &dvfs_idx, sizeof(dvfs_idx));
 626
 627         return ret ? ret : dvfs_idx;
 628 }
 629
 630 static int scpi_dvfs_set_idx(u8 domain, u8 index)
 631 {
 632         int stat;
 633         struct dvfs_set dvfs = {domain, index};
 634
 635         return scpi_send_message(CMD_SET_DVFS, &dvfs, sizeof(dvfs),
 636                                  &stat, sizeof(stat));
 637 }
 638
 639 static int opp_cmp_func(const void *opp1, const void *opp2)
 640 {
 641         const struct scpi_opp *t1 = opp1, *t2 = opp2;
 642
 643         return t1->freq - t2->freq;
 644 }
 645
 646 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
 647 {
 648         struct scpi_dvfs_info *info;
 649         struct scpi_opp *opp;
 650         struct dvfs_info buf;
 651         int ret, i;
 652
 653         if (domain >= MAX_DVFS_DOMAINS)
 654                 return ERR_PTR(-EINVAL);
 655
 656         if (scpi_info->dvfs[domain])    /* data already populated */
 657                 return scpi_info->dvfs[domain];
 658
 659         ret = scpi_send_message(CMD_GET_DVFS_INFO, &domain, sizeof(domain),
 660                                 &buf, sizeof(buf));
 661         if (ret)
 662                 return ERR_PTR(ret);
 663
 664         info = kmalloc(sizeof(*info), GFP_KERNEL);
 665         if (!info)
 666                 return ERR_PTR(-ENOMEM);
 667
 668         info->count = DVFS_OPP_COUNT(buf.header);
 669         info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
 670
 671         info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
 672         if (!info->opps) {
 673                 kfree(info);
 674                 return ERR_PTR(-ENOMEM);
 675         }
 676
 677         for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
 678                 opp->freq = le32_to_cpu(buf.opps[i].freq);
 679                 opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
 680         }
 681
 682         sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
 683
 684         scpi_info->dvfs[domain] = info;
 685         return info;
 686 }
 687
 688 static int scpi_dev_domain_id(struct device *dev)
 689 {
 690         struct of_phandle_args clkspec;
 691
 692         if (of_parse_phandle_with_args(dev->of_node, "clocks", "#clock-cells",
 693                                        0, &clkspec))
 694                 return -EINVAL;
 695
 696         return clkspec.args[0];
 697 }
 698
 699 static struct scpi_dvfs_info *scpi_dvfs_info(struct device *dev)
 700 {
 701         int domain = scpi_dev_domain_id(dev);
 702
 703         if (domain < 0)
 704                 return ERR_PTR(domain);
 705
 706         return scpi_dvfs_get_info(domain);
 707 }
 708
 709 static int scpi_dvfs_get_transition_latency(struct device *dev)
 710 {
 711         struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 712
 713         if (IS_ERR(info))
 714                 return PTR_ERR(info);
 715
 716         if (!info->latency)
 717                 return 0;
 718
 719         return info->latency;
 720 }
 721
 722 static int scpi_dvfs_add_opps_to_device(struct device *dev)
 723 {
 724         int idx, ret;
 725         struct scpi_opp *opp;
 726         struct scpi_dvfs_info *info = scpi_dvfs_info(dev);
 727
 728         if (IS_ERR(info))
 729                 return PTR_ERR(info);
 730
 731         if (!info->opps)
 732                 return -EIO;
 733
 734         for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
 735                 ret = dev_pm_opp_add(dev, opp->freq, opp->m_volt * 1000);
 736                 if (ret) {
 737                         dev_warn(dev, "failed to add opp %uHz %umV\n",
 738                                  opp->freq, opp->m_volt);
 739                         while (idx-- > 0)
 740                                 dev_pm_opp_remove(dev, (--opp)->freq);
 741                         return ret;
 742                 }
 743         }
 744         return 0;
 745 }
 746
 747 static int scpi_sensor_get_capability(u16 *sensors)
 748 {
 749         struct sensor_capabilities cap_buf;
 750         int ret;
 751
 752         ret = scpi_send_message(CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
 753                                 sizeof(cap_buf));
 754         if (!ret)
 755                 *sensors = le16_to_cpu(cap_buf.sensors);
 756
 757         return ret;
 758 }
 759
 760 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
 761 {
 762         __le16 id = cpu_to_le16(sensor_id);
 763         struct _scpi_sensor_info _info;
 764         int ret;
 765
 766         ret = scpi_send_message(CMD_SENSOR_INFO, &id, sizeof(id),
 767                                 &_info, sizeof(_info));
 768         if (!ret) {
 769                 memcpy(info, &_info, sizeof(*info));
 770                 info->sensor_id = le16_to_cpu(_info.sensor_id);
 771         }
 772
 773         return ret;
 774 }
 775
 776 static int scpi_sensor_get_value(u16 sensor, u64 *val)
 777 {
 778         __le16 id = cpu_to_le16(sensor);
 779         struct sensor_value buf;
 780         int ret;
 781
 782         ret = scpi_send_message(CMD_SENSOR_VALUE, &id, sizeof(id),
 783                                 &buf, sizeof(buf));
 784         if (ret)
 785                 return ret;
 786
 787         if (scpi_info->is_legacy)
 788                 /* only 32-bits supported, hi_val can be junk */
 789                 *val = le32_to_cpu(buf.lo_val);
 790         else
 791                 *val = (u64)le32_to_cpu(buf.hi_val) << 32 |
 792                         le32_to_cpu(buf.lo_val);
 793
 794         return 0;
 795 }
 796
 797 static int scpi_device_get_power_state(u16 dev_id)
 798 {
 799         int ret;
 800         u8 pstate;
 801         __le16 id = cpu_to_le16(dev_id);
 802
 803         ret = scpi_send_message(CMD_GET_DEVICE_PWR_STATE, &id,
 804                                 sizeof(id), &pstate, sizeof(pstate));
 805         return ret ? ret : pstate;
 806 }
 807
 808 static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
 809 {
 810         int stat;
 811         struct dev_pstate_set dev_set = {
 812                 .dev_id = cpu_to_le16(dev_id),
 813                 .pstate = pstate,
 814         };
 815
 816         return scpi_send_message(CMD_SET_DEVICE_PWR_STATE, &dev_set,
 817                                  sizeof(dev_set), &stat, sizeof(stat));
 818 }
 819
 820 static struct scpi_ops scpi_ops = {
 821         .get_version = scpi_get_version,
 822         .clk_get_range = scpi_clk_get_range,
 823         .clk_get_val = scpi_clk_get_val,
 824         .clk_set_val = scpi_clk_set_val,
 825         .dvfs_get_idx = scpi_dvfs_get_idx,
 826         .dvfs_set_idx = scpi_dvfs_set_idx,
 827         .dvfs_get_info = scpi_dvfs_get_info,
 828         .device_domain_id = scpi_dev_domain_id,
 829         .get_transition_latency = scpi_dvfs_get_transition_latency,
 830         .add_opps_to_device = scpi_dvfs_add_opps_to_device,
 831         .sensor_get_capability = scpi_sensor_get_capability,
 832         .sensor_get_info = scpi_sensor_get_info,
 833         .sensor_get_value = scpi_sensor_get_value,
 834         .device_get_power_state = scpi_device_get_power_state,
 835         .device_set_power_state = scpi_device_set_power_state,
 836 };
 837
 838 struct scpi_ops *get_scpi_ops(void)
 839 {
 840         return scpi_info ? scpi_info->scpi_ops : NULL;
 841 }
 842 EXPORT_SYMBOL_GPL(get_scpi_ops);
 843
 844 static int scpi_init_versions(struct scpi_drvinfo *info)
 845 {
 846         int ret;
 847         struct scp_capabilities caps;
 848
 849         ret = scpi_send_message(CMD_SCPI_CAPABILITIES, NULL, 0,
 850                                 &caps, sizeof(caps));
 851         if (!ret) {
 852                 info->protocol_version = le32_to_cpu(caps.protocol_version);
 853                 info->firmware_version = le32_to_cpu(caps.platform_version);
 854         }
 855         /* Ignore error if not implemented */
 856         if (scpi_info->is_legacy && ret == -EOPNOTSUPP)
 857                 return 0;
 858
 859         return ret;
 860 }
 861
 862 static ssize_t protocol_version_show(struct device *dev,
 863                                      struct device_attribute *attr, char *buf)
 864 {
 865         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 866
 867         return sprintf(buf, "%d.%d\n",
 868                        PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
 869                        PROTOCOL_REV_MINOR(scpi_info->protocol_version));
 870 }
 871 static DEVICE_ATTR_RO(protocol_version);
 872
 873 static ssize_t firmware_version_show(struct device *dev,
 874                                      struct device_attribute *attr, char *buf)
 875 {
 876         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 877
 878         return sprintf(buf, "%d.%d.%d\n",
 879                        FW_REV_MAJOR(scpi_info->firmware_version),
 880                        FW_REV_MINOR(scpi_info->firmware_version),
 881                        FW_REV_PATCH(scpi_info->firmware_version));
 882 }
 883 static DEVICE_ATTR_RO(firmware_version);
 884
 885 static struct attribute *versions_attrs[] = {
 886         &dev_attr_firmware_version.attr,
 887         &dev_attr_protocol_version.attr,
 888         NULL,
 889 };
 890 ATTRIBUTE_GROUPS(versions);
 891
 892 static void
 893 scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
 894 {
 895         int i;
 896
 897         for (i = 0; i < count && pchan->chan; i++, pchan++) {
 898                 mbox_free_channel(pchan->chan);
 899                 devm_kfree(dev, pchan->xfers);
 900                 devm_iounmap(dev, pchan->rx_payload);
 901         }
 902 }
 903
 904 static int scpi_remove(struct platform_device *pdev)
 905 {
 906         int i;
 907         struct device *dev = &pdev->dev;
 908         struct scpi_drvinfo *info = platform_get_drvdata(pdev);
 909
 910         scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
 911
 912         of_platform_depopulate(dev);
 913         sysfs_remove_groups(&dev->kobj, versions_groups);
 914         scpi_free_channels(dev, info->channels, info->num_chans);
 915         platform_set_drvdata(pdev, NULL);
 916
 917         for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
 918                 kfree(info->dvfs[i]->opps);
 919                 kfree(info->dvfs[i]);
 920         }
 921         devm_kfree(dev, info->channels);
 922         devm_kfree(dev, info);
 923
 924         return 0;
 925 }
 926
 927 #define MAX_SCPI_XFERS          10
 928 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
 929 {
 930         int i;
 931         struct scpi_xfer *xfers;
 932
 933         xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
 934         if (!xfers)
 935                 return -ENOMEM;
 936
 937         ch->xfers = xfers;
 938         for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++) {
 939                 init_completion(&xfers->done);
 940                 list_add_tail(&xfers->node, &ch->xfers_list);
 941         }
 942
 943         return 0;
 944 }
 945
 946 static const struct of_device_id legacy_scpi_of_match[] = {
 947         {.compatible = "arm,scpi-pre-1.0"},
 948         {},
 949 };
 950
 951 static int scpi_probe(struct platform_device *pdev)
 952 {
 953         int count, idx, ret;
 954         struct resource res;
 955         struct scpi_chan *scpi_chan;
 956         struct device *dev = &pdev->dev;
 957         struct device_node *np = dev->of_node;
 958
 959         scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
 960         if (!scpi_info)
 961                 return -ENOMEM;
 962
 963         if (of_match_device(legacy_scpi_of_match, &pdev->dev))
 964                 scpi_info->is_legacy = true;
 965
 966         count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 967         if (count < 0) {
 968                 dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
 969                 return -ENODEV;
 970         }
 971
 972         scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
 973         if (!scpi_chan)
 974                 return -ENOMEM;
 975
 976         for (idx = 0; idx < count; idx++) {
 977                 resource_size_t size;
 978                 struct scpi_chan *pchan = scpi_chan + idx;
 979                 struct mbox_client *cl = &pchan->cl;
 980                 struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 981
 982                 ret = of_address_to_resource(shmem, 0, &res);
 983                 of_node_put(shmem);
 984                 if (ret) {
 985                         dev_err(dev, "failed to get SCPI payload mem resource\n");
 986                         goto err;
 987                 }
 988
 989                 size = resource_size(&res);
 990                 pchan->rx_payload = devm_ioremap(dev, res.start, size);
 991                 if (!pchan->rx_payload) {
 992                         dev_err(dev, "failed to ioremap SCPI payload\n");
 993                         ret = -EADDRNOTAVAIL;
 994                         goto err;
 995                 }
 996                 pchan->tx_payload = pchan->rx_payload + (size >> 1);
 997
 998                 cl->dev = dev;
 999                 cl->rx_callback = scpi_handle_remote_msg;
1000                 cl->tx_prepare = scpi_tx_prepare;
1001                 cl->tx_block = true;
1002                 cl->tx_tout = 20;
1003                 cl->knows_txdone = false; /* controller can't ack */
1004
1005                 INIT_LIST_HEAD(&pchan->rx_pending);
1006                 INIT_LIST_HEAD(&pchan->xfers_list);
1007                 spin_lock_init(&pchan->rx_lock);
1008                 mutex_init(&pchan->xfers_lock);
1009
1010                 ret = scpi_alloc_xfer_list(dev, pchan);
1011                 if (!ret) {
1012                         pchan->chan = mbox_request_channel(cl, idx);
1013                         if (!IS_ERR(pchan->chan))
1014                                 continue;
1015                         ret = PTR_ERR(pchan->chan);
1016                         if (ret != -EPROBE_DEFER)
1017                                 dev_err(dev, "failed to get channel%d err %d\n",
1018                                         idx, ret);
1019                 }
1020 err:
1021                 scpi_free_channels(dev, scpi_chan, idx);
1022                 scpi_info = NULL;
1023                 return ret;
1024         }
1025
1026         scpi_info->channels = scpi_chan;
1027         scpi_info->num_chans = count;
1028         scpi_info->commands = scpi_std_commands;
1029
1030         platform_set_drvdata(pdev, scpi_info);
1031
1032         if (scpi_info->is_legacy) {
1033                 /* Replace with legacy variants */
1034                 scpi_ops.clk_set_val = legacy_scpi_clk_set_val;
1035                 scpi_info->commands = scpi_legacy_commands;
1036
1037                 /* Fill priority bitmap */
1038                 for (idx = 0; idx < ARRAY_SIZE(legacy_hpriority_cmds); idx++)
1039                         set_bit(legacy_hpriority_cmds[idx],
1040                                 scpi_info->cmd_priority);
1041         }
1042
1043         ret = scpi_init_versions(scpi_info);
1044         if (ret) {
1045                 dev_err(dev, "incorrect or no SCP firmware found\n");
1046                 scpi_remove(pdev);
1047                 return ret;
1048         }
1049
1050         _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
1051                   PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
1052                   PROTOCOL_REV_MINOR(scpi_info->protocol_version),
1053                   FW_REV_MAJOR(scpi_info->firmware_version),
1054                   FW_REV_MINOR(scpi_info->firmware_version),
1055                   FW_REV_PATCH(scpi_info->firmware_version));
1056         scpi_info->scpi_ops = &scpi_ops;
1057
1058         ret = sysfs_create_groups(&dev->kobj, versions_groups);
1059         if (ret)
1060                 dev_err(dev, "unable to create sysfs version group\n");
1061
1062         return of_platform_populate(dev->of_node, NULL, NULL, dev);
1063 }
1064
1065 static const struct of_device_id scpi_of_match[] = {
1066         {.compatible = "arm,scpi"},
1067         {.compatible = "arm,scpi-pre-1.0"},
1068         {},
1069 };
1070
1071 MODULE_DEVICE_TABLE(of, scpi_of_match);
1072
1073 static struct platform_driver scpi_driver = {
1074         .driver = {
1075                 .name = "scpi_protocol",
1076                 .of_match_table = scpi_of_match,
1077         },
1078         .probe = scpi_probe,
1079         .remove = scpi_remove,
1080 };
1081 module_platform_driver(scpi_driver);
1082
1083 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
1084 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
1085 MODULE_LICENSE("GPL v2");