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 PACK_SCPI_CMD(cmd_id, tx_sz)                    \
  54         ((((cmd_id) & CMD_ID_MASK) << CMD_ID_SHIFT) |   \
  55         (((tx_sz) & CMD_DATA_SIZE_MASK) << CMD_DATA_SIZE_SHIFT))
  56 #define ADD_SCPI_TOKEN(cmd, token)                      \
  57         ((cmd) |= (((token) & CMD_TOKEN_ID_MASK) << CMD_TOKEN_ID_SHIFT))
  58
  59 #define CMD_SIZE(cmd)   (((cmd) >> CMD_DATA_SIZE_SHIFT) & CMD_DATA_SIZE_MASK)
  60 #define CMD_UNIQ_MASK   (CMD_TOKEN_ID_MASK << CMD_TOKEN_ID_SHIFT | CMD_ID_MASK)
  61 #define CMD_XTRACT_UNIQ(cmd)    ((cmd) & CMD_UNIQ_MASK)
  62
  63 #define SCPI_SLOT               0
  64
  65 #define MAX_DVFS_DOMAINS        8
  66 #define MAX_DVFS_OPPS           8
  67 #define DVFS_LATENCY(hdr)       (le32_to_cpu(hdr) >> 16)
  68 #define DVFS_OPP_COUNT(hdr)     ((le32_to_cpu(hdr) >> 8) & 0xff)
  69
  70 #define PROTOCOL_REV_MINOR_BITS 16
  71 #define PROTOCOL_REV_MINOR_MASK ((1U << PROTOCOL_REV_MINOR_BITS) - 1)
  72 #define PROTOCOL_REV_MAJOR(x)   ((x) >> PROTOCOL_REV_MINOR_BITS)
  73 #define PROTOCOL_REV_MINOR(x)   ((x) & PROTOCOL_REV_MINOR_MASK)
  74
  75 #define FW_REV_MAJOR_BITS       24
  76 #define FW_REV_MINOR_BITS       16
  77 #define FW_REV_PATCH_MASK       ((1U << FW_REV_MINOR_BITS) - 1)
  78 #define FW_REV_MINOR_MASK       ((1U << FW_REV_MAJOR_BITS) - 1)
  79 #define FW_REV_MAJOR(x)         ((x) >> FW_REV_MAJOR_BITS)
  80 #define FW_REV_MINOR(x)         (((x) & FW_REV_MINOR_MASK) >> FW_REV_MINOR_BITS)
  81 #define FW_REV_PATCH(x)         ((x) & FW_REV_PATCH_MASK)
  82
  83 #define MAX_RX_TIMEOUT          (msecs_to_jiffies(30))
  84
  85 enum scpi_error_codes {
  86         SCPI_SUCCESS = 0, /* Success */
  87         SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
  88         SCPI_ERR_ALIGN = 2, /* Invalid alignment */
  89         SCPI_ERR_SIZE = 3, /* Invalid size */
  90         SCPI_ERR_HANDLER = 4, /* Invalid handler/callback */
  91         SCPI_ERR_ACCESS = 5, /* Invalid access/permission denied */
  92         SCPI_ERR_RANGE = 6, /* Value out of range */
  93         SCPI_ERR_TIMEOUT = 7, /* Timeout has occurred */
  94         SCPI_ERR_NOMEM = 8, /* Invalid memory area or pointer */
  95         SCPI_ERR_PWRSTATE = 9, /* Invalid power state */
  96         SCPI_ERR_SUPPORT = 10, /* Not supported or disabled */
  97         SCPI_ERR_DEVICE = 11, /* Device error */
  98         SCPI_ERR_BUSY = 12, /* Device busy */
  99         SCPI_ERR_MAX
 100 };
 101
 102 enum scpi_std_cmd {
 103         SCPI_CMD_INVALID                = 0x00,
 104         SCPI_CMD_SCPI_READY             = 0x01,
 105         SCPI_CMD_SCPI_CAPABILITIES      = 0x02,
 106         SCPI_CMD_SET_CSS_PWR_STATE      = 0x03,
 107         SCPI_CMD_GET_CSS_PWR_STATE      = 0x04,
 108         SCPI_CMD_SET_SYS_PWR_STATE      = 0x05,
 109         SCPI_CMD_SET_CPU_TIMER          = 0x06,
 110         SCPI_CMD_CANCEL_CPU_TIMER       = 0x07,
 111         SCPI_CMD_DVFS_CAPABILITIES      = 0x08,
 112         SCPI_CMD_GET_DVFS_INFO          = 0x09,
 113         SCPI_CMD_SET_DVFS               = 0x0a,
 114         SCPI_CMD_GET_DVFS               = 0x0b,
 115         SCPI_CMD_GET_DVFS_STAT          = 0x0c,
 116         SCPI_CMD_CLOCK_CAPABILITIES     = 0x0d,
 117         SCPI_CMD_GET_CLOCK_INFO         = 0x0e,
 118         SCPI_CMD_SET_CLOCK_VALUE        = 0x0f,
 119         SCPI_CMD_GET_CLOCK_VALUE        = 0x10,
 120         SCPI_CMD_PSU_CAPABILITIES       = 0x11,
 121         SCPI_CMD_GET_PSU_INFO           = 0x12,
 122         SCPI_CMD_SET_PSU                = 0x13,
 123         SCPI_CMD_GET_PSU                = 0x14,
 124         SCPI_CMD_SENSOR_CAPABILITIES    = 0x15,
 125         SCPI_CMD_SENSOR_INFO            = 0x16,
 126         SCPI_CMD_SENSOR_VALUE           = 0x17,
 127         SCPI_CMD_SENSOR_CFG_PERIODIC    = 0x18,
 128         SCPI_CMD_SENSOR_CFG_BOUNDS      = 0x19,
 129         SCPI_CMD_SENSOR_ASYNC_VALUE     = 0x1a,
 130         SCPI_CMD_SET_DEVICE_PWR_STATE   = 0x1b,
 131         SCPI_CMD_GET_DEVICE_PWR_STATE   = 0x1c,
 132         SCPI_CMD_COUNT
 133 };
 134
 135 struct scpi_xfer {
 136         u32 slot; /* has to be first element */
 137         u32 cmd;
 138         u32 status;
 139         const void *tx_buf;
 140         void *rx_buf;
 141         unsigned int tx_len;
 142         unsigned int rx_len;
 143         struct list_head node;
 144         struct completion done;
 145 };
 146
 147 struct scpi_chan {
 148         struct mbox_client cl;
 149         struct mbox_chan *chan;
 150         void __iomem *tx_payload;
 151         void __iomem *rx_payload;
 152         struct list_head rx_pending;
 153         struct list_head xfers_list;
 154         struct scpi_xfer *xfers;
 155         spinlock_t rx_lock; /* locking for the rx pending list */
 156         struct mutex xfers_lock;
 157         u8 token;
 158 };
 159
 160 struct scpi_drvinfo {
 161         u32 protocol_version;
 162         u32 firmware_version;
 163         int num_chans;
 164         atomic_t next_chan;
 165         struct scpi_ops *scpi_ops;
 166         struct scpi_chan *channels;
 167         struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
 168 };
 169
 170 /*
 171  * The SCP firmware only executes in little-endian mode, so any buffers
 172  * shared through SCPI should have their contents converted to little-endian
 173  */
 174 struct scpi_shared_mem {
 175         __le32 command;
 176         __le32 status;
 177         u8 payload[0];
 178 } __packed;
 179
 180 struct scp_capabilities {
 181         __le32 protocol_version;
 182         __le32 event_version;
 183         __le32 platform_version;
 184         __le32 commands[4];
 185 } __packed;
 186
 187 struct clk_get_info {
 188         __le16 id;
 189         __le16 flags;
 190         __le32 min_rate;
 191         __le32 max_rate;
 192         u8 name[20];
 193 } __packed;
 194
 195 struct clk_get_value {
 196         __le32 rate;
 197 } __packed;
 198
 199 struct clk_set_value {
 200         __le16 id;
 201         __le16 reserved;
 202         __le32 rate;
 203 } __packed;
 204
 205 struct dvfs_info {
 206         __le32 header;
 207         struct {
 208                 __le32 freq;
 209                 __le32 m_volt;
 210         } opps[MAX_DVFS_OPPS];
 211 } __packed;
 212
 213 struct dvfs_get {
 214         u8 index;
 215 } __packed;
 216
 217 struct dvfs_set {
 218         u8 domain;
 219         u8 index;
 220 } __packed;
 221
 222 struct sensor_capabilities {
 223         __le16 sensors;
 224 } __packed;
 225
 226 struct _scpi_sensor_info {
 227         __le16 sensor_id;
 228         u8 class;
 229         u8 trigger_type;
 230         char name[20];
 231 };
 232
 233 struct sensor_value {
 234         __le32 lo_val;
 235         __le32 hi_val;
 236 } __packed;
 237
 238 static struct scpi_drvinfo *scpi_info;
 239
 240 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
 241         /* better than switch case as long as return value is continuous */
 242         0, /* SCPI_SUCCESS */
 243         -EINVAL, /* SCPI_ERR_PARAM */
 244         -ENOEXEC, /* SCPI_ERR_ALIGN */
 245         -EMSGSIZE, /* SCPI_ERR_SIZE */
 246         -EINVAL, /* SCPI_ERR_HANDLER */
 247         -EACCES, /* SCPI_ERR_ACCESS */
 248         -ERANGE, /* SCPI_ERR_RANGE */
 249         -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
 250         -ENOMEM, /* SCPI_ERR_NOMEM */
 251         -EINVAL, /* SCPI_ERR_PWRSTATE */
 252         -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
 253         -EIO, /* SCPI_ERR_DEVICE */
 254         -EBUSY, /* SCPI_ERR_BUSY */
 255 };
 256
 257 static inline int scpi_to_linux_errno(int errno)
 258 {
 259         if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
 260                 return scpi_linux_errmap[errno];
 261         return -EIO;
 262 }
 263
 264 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
 265 {
 266         unsigned long flags;
 267         struct scpi_xfer *t, *match = NULL;
 268
 269         spin_lock_irqsave(&ch->rx_lock, flags);
 270         if (list_empty(&ch->rx_pending)) {
 271                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 272                 return;
 273         }
 274
 275         list_for_each_entry(t, &ch->rx_pending, node)
 276                 if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
 277                         list_del(&t->node);
 278                         match = t;
 279                         break;
 280                 }
 281         /* check if wait_for_completion is in progress or timed-out */
 282         if (match && !completion_done(&match->done)) {
 283                 struct scpi_shared_mem *mem = ch->rx_payload;
 284                 unsigned int len = min(match->rx_len, CMD_SIZE(cmd));
 285
 286                 match->status = le32_to_cpu(mem->status);
 287                 memcpy_fromio(match->rx_buf, mem->payload, len);
 288                 if (match->rx_len > len)
 289                         memset(match->rx_buf + len, 0, match->rx_len - len);
 290                 complete(&match->done);
 291         }
 292         spin_unlock_irqrestore(&ch->rx_lock, flags);
 293 }
 294
 295 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
 296 {
 297         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 298         struct scpi_shared_mem *mem = ch->rx_payload;
 299         u32 cmd = le32_to_cpu(mem->command);
 300
 301         scpi_process_cmd(ch, cmd);
 302 }
 303
 304 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
 305 {
 306         unsigned long flags;
 307         struct scpi_xfer *t = msg;
 308         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 309         struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
 310
 311         if (t->tx_buf)
 312                 memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
 313         if (t->rx_buf) {
 314                 if (!(++ch->token))
 315                         ++ch->token;
 316                 ADD_SCPI_TOKEN(t->cmd, ch->token);
 317                 spin_lock_irqsave(&ch->rx_lock, flags);
 318                 list_add_tail(&t->node, &ch->rx_pending);
 319                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 320         }
 321         mem->command = cpu_to_le32(t->cmd);
 322 }
 323
 324 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
 325 {
 326         struct scpi_xfer *t;
 327
 328         mutex_lock(&ch->xfers_lock);
 329         if (list_empty(&ch->xfers_list)) {
 330                 mutex_unlock(&ch->xfers_lock);
 331                 return NULL;
 332         }
 333         t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
 334         list_del(&t->node);
 335         mutex_unlock(&ch->xfers_lock);
 336         return t;
 337 }
 338
 339 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
 340 {
 341         mutex_lock(&ch->xfers_lock);
 342         list_add_tail(&t->node, &ch->xfers_list);
 343         mutex_unlock(&ch->xfers_lock);
 344 }
 345
 346 static int scpi_send_message(u8 cmd, void *tx_buf, unsigned int tx_len,
 347                              void *rx_buf, unsigned int rx_len)
 348 {
 349         int ret;
 350         u8 chan;
 351         struct scpi_xfer *msg;
 352         struct scpi_chan *scpi_chan;
 353
 354         chan = atomic_inc_return(&scpi_info->next_chan) % scpi_info->num_chans;
 355         scpi_chan = scpi_info->channels + chan;
 356
 357         msg = get_scpi_xfer(scpi_chan);
 358         if (!msg)
 359                 return -ENOMEM;
 360
 361         msg->slot = BIT(SCPI_SLOT);
 362         msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
 363         msg->tx_buf = tx_buf;
 364         msg->tx_len = tx_len;
 365         msg->rx_buf = rx_buf;
 366         msg->rx_len = rx_len;
 367         init_completion(&msg->done);
 368
 369         ret = mbox_send_message(scpi_chan->chan, msg);
 370         if (ret < 0 || !rx_buf)
 371                 goto out;
 372
 373         if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
 374                 ret = -ETIMEDOUT;
 375         else
 376                 /* first status word */
 377                 ret = msg->status;
 378 out:
 379         if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
 380                 scpi_process_cmd(scpi_chan, msg->cmd);
 381
 382         put_scpi_xfer(msg, scpi_chan);
 383         /* SCPI error codes > 0, translate them to Linux scale*/
 384         return ret > 0 ? scpi_to_linux_errno(ret) : ret;
 385 }
 386
 387 static u32 scpi_get_version(void)
 388 {
 389         return scpi_info->protocol_version;
 390 }
 391
 392 static int
 393 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
 394 {
 395         int ret;
 396         struct clk_get_info clk;
 397         __le16 le_clk_id = cpu_to_le16(clk_id);
 398
 399         ret = scpi_send_message(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
 400                                 sizeof(le_clk_id), &clk, sizeof(clk));
 401         if (!ret) {
 402                 *min = le32_to_cpu(clk.min_rate);
 403                 *max = le32_to_cpu(clk.max_rate);
 404         }
 405         return ret;
 406 }
 407
 408 static unsigned long scpi_clk_get_val(u16 clk_id)
 409 {
 410         int ret;
 411         struct clk_get_value clk;
 412         __le16 le_clk_id = cpu_to_le16(clk_id);
 413
 414         ret = scpi_send_message(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
 415                                 sizeof(le_clk_id), &clk, sizeof(clk));
 416         return ret ? ret : le32_to_cpu(clk.rate);
 417 }
 418
 419 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
 420 {
 421         int stat;
 422         struct clk_set_value clk = {
 423                 .id = cpu_to_le16(clk_id),
 424                 .rate = cpu_to_le32(rate)
 425         };
 426
 427         return scpi_send_message(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 428                                  &stat, sizeof(stat));
 429 }
 430
 431 static int scpi_dvfs_get_idx(u8 domain)
 432 {
 433         int ret;
 434         struct dvfs_get dvfs;
 435
 436         ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
 437                                 &dvfs, sizeof(dvfs));
 438         return ret ? ret : dvfs.index;
 439 }
 440
 441 static int scpi_dvfs_set_idx(u8 domain, u8 index)
 442 {
 443         int stat;
 444         struct dvfs_set dvfs = {domain, index};
 445
 446         return scpi_send_message(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
 447                                  &stat, sizeof(stat));
 448 }
 449
 450 static int opp_cmp_func(const void *opp1, const void *opp2)
 451 {
 452         const struct scpi_opp *t1 = opp1, *t2 = opp2;
 453
 454         return t1->freq - t2->freq;
 455 }
 456
 457 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
 458 {
 459         struct scpi_dvfs_info *info;
 460         struct scpi_opp *opp;
 461         struct dvfs_info buf;
 462         int ret, i;
 463
 464         if (domain >= MAX_DVFS_DOMAINS)
 465                 return ERR_PTR(-EINVAL);
 466
 467         if (scpi_info->dvfs[domain])    /* data already populated */
 468                 return scpi_info->dvfs[domain];
 469
 470         ret = scpi_send_message(SCPI_CMD_GET_DVFS_INFO, &domain, sizeof(domain),
 471                                 &buf, sizeof(buf));
 472
 473         if (ret)
 474                 return ERR_PTR(ret);
 475
 476         info = kmalloc(sizeof(*info), GFP_KERNEL);
 477         if (!info)
 478                 return ERR_PTR(-ENOMEM);
 479
 480         info->count = DVFS_OPP_COUNT(buf.header);
 481         info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
 482
 483         info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
 484         if (!info->opps) {
 485                 kfree(info);
 486                 return ERR_PTR(-ENOMEM);
 487         }
 488
 489         for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
 490                 opp->freq = le32_to_cpu(buf.opps[i].freq);
 491                 opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
 492         }
 493
 494         sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
 495
 496         scpi_info->dvfs[domain] = info;
 497         return info;
 498 }
 499
 500 static int scpi_sensor_get_capability(u16 *sensors)
 501 {
 502         struct sensor_capabilities cap_buf;
 503         int ret;
 504
 505         ret = scpi_send_message(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
 506                                 sizeof(cap_buf));
 507         if (!ret)
 508                 *sensors = le16_to_cpu(cap_buf.sensors);
 509
 510         return ret;
 511 }
 512
 513 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
 514 {
 515         __le16 id = cpu_to_le16(sensor_id);
 516         struct _scpi_sensor_info _info;
 517         int ret;
 518
 519         ret = scpi_send_message(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
 520                                 &_info, sizeof(_info));
 521         if (!ret) {
 522                 memcpy(info, &_info, sizeof(*info));
 523                 info->sensor_id = le16_to_cpu(_info.sensor_id);
 524         }
 525
 526         return ret;
 527 }
 528
 529 int scpi_sensor_get_value(u16 sensor, u64 *val)
 530 {
 531         __le16 id = cpu_to_le16(sensor);
 532         struct sensor_value buf;
 533         int ret;
 534
 535         ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &id, sizeof(id),
 536                                 &buf, sizeof(buf));
 537         if (!ret)
 538                 *val = (u64)le32_to_cpu(buf.hi_val) << 32 |
 539                         le32_to_cpu(buf.lo_val);
 540
 541         return ret;
 542 }
 543
 544 static struct scpi_ops scpi_ops = {
 545         .get_version = scpi_get_version,
 546         .clk_get_range = scpi_clk_get_range,
 547         .clk_get_val = scpi_clk_get_val,
 548         .clk_set_val = scpi_clk_set_val,
 549         .dvfs_get_idx = scpi_dvfs_get_idx,
 550         .dvfs_set_idx = scpi_dvfs_set_idx,
 551         .dvfs_get_info = scpi_dvfs_get_info,
 552         .sensor_get_capability = scpi_sensor_get_capability,
 553         .sensor_get_info = scpi_sensor_get_info,
 554         .sensor_get_value = scpi_sensor_get_value,
 555 };
 556
 557 struct scpi_ops *get_scpi_ops(void)
 558 {
 559         return scpi_info ? scpi_info->scpi_ops : NULL;
 560 }
 561 EXPORT_SYMBOL_GPL(get_scpi_ops);
 562
 563 static int scpi_init_versions(struct scpi_drvinfo *info)
 564 {
 565         int ret;
 566         struct scp_capabilities caps;
 567
 568         ret = scpi_send_message(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
 569                                 &caps, sizeof(caps));
 570         if (!ret) {
 571                 info->protocol_version = le32_to_cpu(caps.protocol_version);
 572                 info->firmware_version = le32_to_cpu(caps.platform_version);
 573         }
 574         return ret;
 575 }
 576
 577 static ssize_t protocol_version_show(struct device *dev,
 578                                      struct device_attribute *attr, char *buf)
 579 {
 580         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 581
 582         return sprintf(buf, "%d.%d\n",
 583                        PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
 584                        PROTOCOL_REV_MINOR(scpi_info->protocol_version));
 585 }
 586 static DEVICE_ATTR_RO(protocol_version);
 587
 588 static ssize_t firmware_version_show(struct device *dev,
 589                                      struct device_attribute *attr, char *buf)
 590 {
 591         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 592
 593         return sprintf(buf, "%d.%d.%d\n",
 594                        FW_REV_MAJOR(scpi_info->firmware_version),
 595                        FW_REV_MINOR(scpi_info->firmware_version),
 596                        FW_REV_PATCH(scpi_info->firmware_version));
 597 }
 598 static DEVICE_ATTR_RO(firmware_version);
 599
 600 static struct attribute *versions_attrs[] = {
 601         &dev_attr_firmware_version.attr,
 602         &dev_attr_protocol_version.attr,
 603         NULL,
 604 };
 605 ATTRIBUTE_GROUPS(versions);
 606
 607 static void
 608 scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
 609 {
 610         int i;
 611
 612         for (i = 0; i < count && pchan->chan; i++, pchan++) {
 613                 mbox_free_channel(pchan->chan);
 614                 devm_kfree(dev, pchan->xfers);
 615                 devm_iounmap(dev, pchan->rx_payload);
 616         }
 617 }
 618
 619 static int scpi_remove(struct platform_device *pdev)
 620 {
 621         int i;
 622         struct device *dev = &pdev->dev;
 623         struct scpi_drvinfo *info = platform_get_drvdata(pdev);
 624
 625         scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
 626
 627         of_platform_depopulate(dev);
 628         sysfs_remove_groups(&dev->kobj, versions_groups);
 629         scpi_free_channels(dev, info->channels, info->num_chans);
 630         platform_set_drvdata(pdev, NULL);
 631
 632         for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
 633                 kfree(info->dvfs[i]->opps);
 634                 kfree(info->dvfs[i]);
 635         }
 636         devm_kfree(dev, info->channels);
 637         devm_kfree(dev, info);
 638
 639         return 0;
 640 }
 641
 642 #define MAX_SCPI_XFERS          10
 643 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
 644 {
 645         int i;
 646         struct scpi_xfer *xfers;
 647
 648         xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
 649         if (!xfers)
 650                 return -ENOMEM;
 651
 652         ch->xfers = xfers;
 653         for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++)
 654                 list_add_tail(&xfers->node, &ch->xfers_list);
 655         return 0;
 656 }
 657
 658 static int scpi_probe(struct platform_device *pdev)
 659 {
 660         int count, idx, ret;
 661         struct resource res;
 662         struct scpi_chan *scpi_chan;
 663         struct device *dev = &pdev->dev;
 664         struct device_node *np = dev->of_node;
 665
 666         scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
 667         if (!scpi_info)
 668                 return -ENOMEM;
 669
 670         count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 671         if (count < 0) {
 672                 dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
 673                 return -ENODEV;
 674         }
 675
 676         scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
 677         if (!scpi_chan)
 678                 return -ENOMEM;
 679
 680         for (idx = 0; idx < count; idx++) {
 681                 resource_size_t size;
 682                 struct scpi_chan *pchan = scpi_chan + idx;
 683                 struct mbox_client *cl = &pchan->cl;
 684                 struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 685
 686                 if (of_address_to_resource(shmem, 0, &res)) {
 687                         dev_err(dev, "failed to get SCPI payload mem resource\n");
 688                         ret = -EINVAL;
 689                         goto err;
 690                 }
 691
 692                 size = resource_size(&res);
 693                 pchan->rx_payload = devm_ioremap(dev, res.start, size);
 694                 if (!pchan->rx_payload) {
 695                         dev_err(dev, "failed to ioremap SCPI payload\n");
 696                         ret = -EADDRNOTAVAIL;
 697                         goto err;
 698                 }
 699                 pchan->tx_payload = pchan->rx_payload + (size >> 1);
 700
 701                 cl->dev = dev;
 702                 cl->rx_callback = scpi_handle_remote_msg;
 703                 cl->tx_prepare = scpi_tx_prepare;
 704                 cl->tx_block = true;
 705                 cl->tx_tout = 20;
 706                 cl->knows_txdone = false; /* controller can't ack */
 707
 708                 INIT_LIST_HEAD(&pchan->rx_pending);
 709                 INIT_LIST_HEAD(&pchan->xfers_list);
 710                 spin_lock_init(&pchan->rx_lock);
 711                 mutex_init(&pchan->xfers_lock);
 712
 713                 ret = scpi_alloc_xfer_list(dev, pchan);
 714                 if (!ret) {
 715                         pchan->chan = mbox_request_channel(cl, idx);
 716                         if (!IS_ERR(pchan->chan))
 717                                 continue;
 718                         ret = PTR_ERR(pchan->chan);
 719                         if (ret != -EPROBE_DEFER)
 720                                 dev_err(dev, "failed to get channel%d err %d\n",
 721                                         idx, ret);
 722                 }
 723 err:
 724                 scpi_free_channels(dev, scpi_chan, idx);
 725                 scpi_info = NULL;
 726                 return ret;
 727         }
 728
 729         scpi_info->channels = scpi_chan;
 730         scpi_info->num_chans = count;
 731         platform_set_drvdata(pdev, scpi_info);
 732
 733         ret = scpi_init_versions(scpi_info);
 734         if (ret) {
 735                 dev_err(dev, "incorrect or no SCP firmware found\n");
 736                 scpi_remove(pdev);
 737                 return ret;
 738         }
 739
 740         _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
 741                   PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
 742                   PROTOCOL_REV_MINOR(scpi_info->protocol_version),
 743                   FW_REV_MAJOR(scpi_info->firmware_version),
 744                   FW_REV_MINOR(scpi_info->firmware_version),
 745                   FW_REV_PATCH(scpi_info->firmware_version));
 746         scpi_info->scpi_ops = &scpi_ops;
 747
 748         ret = sysfs_create_groups(&dev->kobj, versions_groups);
 749         if (ret)
 750                 dev_err(dev, "unable to create sysfs version group\n");
 751
 752         return of_platform_populate(dev->of_node, NULL, NULL, dev);
 753 }
 754
 755 static const struct of_device_id scpi_of_match[] = {
 756         {.compatible = "arm,scpi"},
 757         {},
 758 };
 759
 760 MODULE_DEVICE_TABLE(of, scpi_of_match);
 761
 762 static struct platform_driver scpi_driver = {
 763         .driver = {
 764                 .name = "scpi_protocol",
 765                 .of_match_table = scpi_of_match,
 766         },
 767         .probe = scpi_probe,
 768         .remove = scpi_remove,
 769 };
 770 module_platform_driver(scpi_driver);
 771
 772 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 773 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
 774 MODULE_LICENSE("GPL v2");