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