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(20))
  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 val;
 235 } __packed;
 236
 237 static struct scpi_drvinfo *scpi_info;
 238
 239 static int scpi_linux_errmap[SCPI_ERR_MAX] = {
 240         /* better than switch case as long as return value is continuous */
 241         0, /* SCPI_SUCCESS */
 242         -EINVAL, /* SCPI_ERR_PARAM */
 243         -ENOEXEC, /* SCPI_ERR_ALIGN */
 244         -EMSGSIZE, /* SCPI_ERR_SIZE */
 245         -EINVAL, /* SCPI_ERR_HANDLER */
 246         -EACCES, /* SCPI_ERR_ACCESS */
 247         -ERANGE, /* SCPI_ERR_RANGE */
 248         -ETIMEDOUT, /* SCPI_ERR_TIMEOUT */
 249         -ENOMEM, /* SCPI_ERR_NOMEM */
 250         -EINVAL, /* SCPI_ERR_PWRSTATE */
 251         -EOPNOTSUPP, /* SCPI_ERR_SUPPORT */
 252         -EIO, /* SCPI_ERR_DEVICE */
 253         -EBUSY, /* SCPI_ERR_BUSY */
 254 };
 255
 256 static inline int scpi_to_linux_errno(int errno)
 257 {
 258         if (errno >= SCPI_SUCCESS && errno < SCPI_ERR_MAX)
 259                 return scpi_linux_errmap[errno];
 260         return -EIO;
 261 }
 262
 263 static void scpi_process_cmd(struct scpi_chan *ch, u32 cmd)
 264 {
 265         unsigned long flags;
 266         struct scpi_xfer *t, *match = NULL;
 267
 268         spin_lock_irqsave(&ch->rx_lock, flags);
 269         if (list_empty(&ch->rx_pending)) {
 270                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 271                 return;
 272         }
 273
 274         list_for_each_entry(t, &ch->rx_pending, node)
 275                 if (CMD_XTRACT_UNIQ(t->cmd) == CMD_XTRACT_UNIQ(cmd)) {
 276                         list_del(&t->node);
 277                         match = t;
 278                         break;
 279                 }
 280         /* check if wait_for_completion is in progress or timed-out */
 281         if (match && !completion_done(&match->done)) {
 282                 struct scpi_shared_mem *mem = ch->rx_payload;
 283                 unsigned int len = min(match->rx_len, CMD_SIZE(cmd));
 284
 285                 match->status = le32_to_cpu(mem->status);
 286                 memcpy_fromio(match->rx_buf, mem->payload, len);
 287                 if (match->rx_len > len)
 288                         memset(match->rx_buf + len, 0, match->rx_len - len);
 289                 complete(&match->done);
 290         }
 291         spin_unlock_irqrestore(&ch->rx_lock, flags);
 292 }
 293
 294 static void scpi_handle_remote_msg(struct mbox_client *c, void *msg)
 295 {
 296         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 297         struct scpi_shared_mem *mem = ch->rx_payload;
 298         u32 cmd = le32_to_cpu(mem->command);
 299
 300         scpi_process_cmd(ch, cmd);
 301 }
 302
 303 static void scpi_tx_prepare(struct mbox_client *c, void *msg)
 304 {
 305         unsigned long flags;
 306         struct scpi_xfer *t = msg;
 307         struct scpi_chan *ch = container_of(c, struct scpi_chan, cl);
 308         struct scpi_shared_mem *mem = (struct scpi_shared_mem *)ch->tx_payload;
 309
 310         if (t->tx_buf)
 311                 memcpy_toio(mem->payload, t->tx_buf, t->tx_len);
 312         if (t->rx_buf) {
 313                 if (!(++ch->token))
 314                         ++ch->token;
 315                 ADD_SCPI_TOKEN(t->cmd, ch->token);
 316                 spin_lock_irqsave(&ch->rx_lock, flags);
 317                 list_add_tail(&t->node, &ch->rx_pending);
 318                 spin_unlock_irqrestore(&ch->rx_lock, flags);
 319         }
 320         mem->command = cpu_to_le32(t->cmd);
 321 }
 322
 323 static struct scpi_xfer *get_scpi_xfer(struct scpi_chan *ch)
 324 {
 325         struct scpi_xfer *t;
 326
 327         mutex_lock(&ch->xfers_lock);
 328         if (list_empty(&ch->xfers_list)) {
 329                 mutex_unlock(&ch->xfers_lock);
 330                 return NULL;
 331         }
 332         t = list_first_entry(&ch->xfers_list, struct scpi_xfer, node);
 333         list_del(&t->node);
 334         mutex_unlock(&ch->xfers_lock);
 335         return t;
 336 }
 337
 338 static void put_scpi_xfer(struct scpi_xfer *t, struct scpi_chan *ch)
 339 {
 340         mutex_lock(&ch->xfers_lock);
 341         list_add_tail(&t->node, &ch->xfers_list);
 342         mutex_unlock(&ch->xfers_lock);
 343 }
 344
 345 static int scpi_send_message(u8 cmd, void *tx_buf, unsigned int tx_len,
 346                              void *rx_buf, unsigned int rx_len)
 347 {
 348         int ret;
 349         u8 chan;
 350         struct scpi_xfer *msg;
 351         struct scpi_chan *scpi_chan;
 352
 353         chan = atomic_inc_return(&scpi_info->next_chan) % scpi_info->num_chans;
 354         scpi_chan = scpi_info->channels + chan;
 355
 356         msg = get_scpi_xfer(scpi_chan);
 357         if (!msg)
 358                 return -ENOMEM;
 359
 360         msg->slot = BIT(SCPI_SLOT);
 361         msg->cmd = PACK_SCPI_CMD(cmd, tx_len);
 362         msg->tx_buf = tx_buf;
 363         msg->tx_len = tx_len;
 364         msg->rx_buf = rx_buf;
 365         msg->rx_len = rx_len;
 366         init_completion(&msg->done);
 367
 368         ret = mbox_send_message(scpi_chan->chan, msg);
 369         if (ret < 0 || !rx_buf)
 370                 goto out;
 371
 372         if (!wait_for_completion_timeout(&msg->done, MAX_RX_TIMEOUT))
 373                 ret = -ETIMEDOUT;
 374         else
 375                 /* first status word */
 376                 ret = le32_to_cpu(msg->status);
 377 out:
 378         if (ret < 0 && rx_buf) /* remove entry from the list if timed-out */
 379                 scpi_process_cmd(scpi_chan, msg->cmd);
 380
 381         put_scpi_xfer(msg, scpi_chan);
 382         /* SCPI error codes > 0, translate them to Linux scale*/
 383         return ret > 0 ? scpi_to_linux_errno(ret) : ret;
 384 }
 385
 386 static u32 scpi_get_version(void)
 387 {
 388         return scpi_info->protocol_version;
 389 }
 390
 391 static int
 392 scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
 393 {
 394         int ret;
 395         struct clk_get_info clk;
 396         __le16 le_clk_id = cpu_to_le16(clk_id);
 397
 398         ret = scpi_send_message(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
 399                                 sizeof(le_clk_id), &clk, sizeof(clk));
 400         if (!ret) {
 401                 *min = le32_to_cpu(clk.min_rate);
 402                 *max = le32_to_cpu(clk.max_rate);
 403         }
 404         return ret;
 405 }
 406
 407 static unsigned long scpi_clk_get_val(u16 clk_id)
 408 {
 409         int ret;
 410         struct clk_get_value clk;
 411         __le16 le_clk_id = cpu_to_le16(clk_id);
 412
 413         ret = scpi_send_message(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
 414                                 sizeof(le_clk_id), &clk, sizeof(clk));
 415         return ret ? ret : le32_to_cpu(clk.rate);
 416 }
 417
 418 static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
 419 {
 420         int stat;
 421         struct clk_set_value clk = {
 422                 .id = cpu_to_le16(clk_id),
 423                 .rate = cpu_to_le32(rate)
 424         };
 425
 426         return scpi_send_message(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
 427                                  &stat, sizeof(stat));
 428 }
 429
 430 static int scpi_dvfs_get_idx(u8 domain)
 431 {
 432         int ret;
 433         struct dvfs_get dvfs;
 434
 435         ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
 436                                 &dvfs, sizeof(dvfs));
 437         return ret ? ret : dvfs.index;
 438 }
 439
 440 static int scpi_dvfs_set_idx(u8 domain, u8 index)
 441 {
 442         int stat;
 443         struct dvfs_set dvfs = {domain, index};
 444
 445         return scpi_send_message(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
 446                                  &stat, sizeof(stat));
 447 }
 448
 449 static int opp_cmp_func(const void *opp1, const void *opp2)
 450 {
 451         const struct scpi_opp *t1 = opp1, *t2 = opp2;
 452
 453         return t1->freq - t2->freq;
 454 }
 455
 456 static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
 457 {
 458         struct scpi_dvfs_info *info;
 459         struct scpi_opp *opp;
 460         struct dvfs_info buf;
 461         int ret, i;
 462
 463         if (domain >= MAX_DVFS_DOMAINS)
 464                 return ERR_PTR(-EINVAL);
 465
 466         if (scpi_info->dvfs[domain])    /* data already populated */
 467                 return scpi_info->dvfs[domain];
 468
 469         ret = scpi_send_message(SCPI_CMD_GET_DVFS_INFO, &domain, sizeof(domain),
 470                                 &buf, sizeof(buf));
 471
 472         if (ret)
 473                 return ERR_PTR(ret);
 474
 475         info = kmalloc(sizeof(*info), GFP_KERNEL);
 476         if (!info)
 477                 return ERR_PTR(-ENOMEM);
 478
 479         info->count = DVFS_OPP_COUNT(buf.header);
 480         info->latency = DVFS_LATENCY(buf.header) * 1000; /* uS to nS */
 481
 482         info->opps = kcalloc(info->count, sizeof(*opp), GFP_KERNEL);
 483         if (!info->opps) {
 484                 kfree(info);
 485                 return ERR_PTR(-ENOMEM);
 486         }
 487
 488         for (i = 0, opp = info->opps; i < info->count; i++, opp++) {
 489                 opp->freq = le32_to_cpu(buf.opps[i].freq);
 490                 opp->m_volt = le32_to_cpu(buf.opps[i].m_volt);
 491         }
 492
 493         sort(info->opps, info->count, sizeof(*opp), opp_cmp_func, NULL);
 494
 495         scpi_info->dvfs[domain] = info;
 496         return info;
 497 }
 498
 499 static int scpi_sensor_get_capability(u16 *sensors)
 500 {
 501         struct sensor_capabilities cap_buf;
 502         int ret;
 503
 504         ret = scpi_send_message(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
 505                                 sizeof(cap_buf));
 506         if (!ret)
 507                 *sensors = le16_to_cpu(cap_buf.sensors);
 508
 509         return ret;
 510 }
 511
 512 static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
 513 {
 514         __le16 id = cpu_to_le16(sensor_id);
 515         struct _scpi_sensor_info _info;
 516         int ret;
 517
 518         ret = scpi_send_message(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
 519                                 &_info, sizeof(_info));
 520         if (!ret) {
 521                 memcpy(info, &_info, sizeof(*info));
 522                 info->sensor_id = le16_to_cpu(_info.sensor_id);
 523         }
 524
 525         return ret;
 526 }
 527
 528 int scpi_sensor_get_value(u16 sensor, u32 *val)
 529 {
 530         struct sensor_value buf;
 531         int ret;
 532
 533         ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &sensor, sizeof(sensor),
 534                                 &buf, sizeof(buf));
 535         if (!ret)
 536                 *val = le32_to_cpu(buf.val);
 537
 538         return ret;
 539 }
 540
 541 static struct scpi_ops scpi_ops = {
 542         .get_version = scpi_get_version,
 543         .clk_get_range = scpi_clk_get_range,
 544         .clk_get_val = scpi_clk_get_val,
 545         .clk_set_val = scpi_clk_set_val,
 546         .dvfs_get_idx = scpi_dvfs_get_idx,
 547         .dvfs_set_idx = scpi_dvfs_set_idx,
 548         .dvfs_get_info = scpi_dvfs_get_info,
 549         .sensor_get_capability = scpi_sensor_get_capability,
 550         .sensor_get_info = scpi_sensor_get_info,
 551         .sensor_get_value = scpi_sensor_get_value,
 552 };
 553
 554 struct scpi_ops *get_scpi_ops(void)
 555 {
 556         return scpi_info ? scpi_info->scpi_ops : NULL;
 557 }
 558 EXPORT_SYMBOL_GPL(get_scpi_ops);
 559
 560 static int scpi_init_versions(struct scpi_drvinfo *info)
 561 {
 562         int ret;
 563         struct scp_capabilities caps;
 564
 565         ret = scpi_send_message(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
 566                                 &caps, sizeof(caps));
 567         if (!ret) {
 568                 info->protocol_version = le32_to_cpu(caps.protocol_version);
 569                 info->firmware_version = le32_to_cpu(caps.platform_version);
 570         }
 571         return ret;
 572 }
 573
 574 static ssize_t protocol_version_show(struct device *dev,
 575                                      struct device_attribute *attr, char *buf)
 576 {
 577         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 578
 579         return sprintf(buf, "%d.%d\n",
 580                        PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
 581                        PROTOCOL_REV_MINOR(scpi_info->protocol_version));
 582 }
 583 static DEVICE_ATTR_RO(protocol_version);
 584
 585 static ssize_t firmware_version_show(struct device *dev,
 586                                      struct device_attribute *attr, char *buf)
 587 {
 588         struct scpi_drvinfo *scpi_info = dev_get_drvdata(dev);
 589
 590         return sprintf(buf, "%d.%d.%d\n",
 591                        FW_REV_MAJOR(scpi_info->firmware_version),
 592                        FW_REV_MINOR(scpi_info->firmware_version),
 593                        FW_REV_PATCH(scpi_info->firmware_version));
 594 }
 595 static DEVICE_ATTR_RO(firmware_version);
 596
 597 static struct attribute *versions_attrs[] = {
 598         &dev_attr_firmware_version.attr,
 599         &dev_attr_protocol_version.attr,
 600         NULL,
 601 };
 602 ATTRIBUTE_GROUPS(versions);
 603
 604 static void
 605 scpi_free_channels(struct device *dev, struct scpi_chan *pchan, int count)
 606 {
 607         int i;
 608
 609         for (i = 0; i < count && pchan->chan; i++, pchan++) {
 610                 mbox_free_channel(pchan->chan);
 611                 devm_kfree(dev, pchan->xfers);
 612                 devm_iounmap(dev, pchan->rx_payload);
 613         }
 614 }
 615
 616 static int scpi_remove(struct platform_device *pdev)
 617 {
 618         int i;
 619         struct device *dev = &pdev->dev;
 620         struct scpi_drvinfo *info = platform_get_drvdata(pdev);
 621
 622         scpi_info = NULL; /* stop exporting SCPI ops through get_scpi_ops */
 623
 624         of_platform_depopulate(dev);
 625         sysfs_remove_groups(&dev->kobj, versions_groups);
 626         scpi_free_channels(dev, info->channels, info->num_chans);
 627         platform_set_drvdata(pdev, NULL);
 628
 629         for (i = 0; i < MAX_DVFS_DOMAINS && info->dvfs[i]; i++) {
 630                 kfree(info->dvfs[i]->opps);
 631                 kfree(info->dvfs[i]);
 632         }
 633         devm_kfree(dev, info->channels);
 634         devm_kfree(dev, info);
 635
 636         return 0;
 637 }
 638
 639 #define MAX_SCPI_XFERS          10
 640 static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
 641 {
 642         int i;
 643         struct scpi_xfer *xfers;
 644
 645         xfers = devm_kzalloc(dev, MAX_SCPI_XFERS * sizeof(*xfers), GFP_KERNEL);
 646         if (!xfers)
 647                 return -ENOMEM;
 648
 649         ch->xfers = xfers;
 650         for (i = 0; i < MAX_SCPI_XFERS; i++, xfers++)
 651                 list_add_tail(&xfers->node, &ch->xfers_list);
 652         return 0;
 653 }
 654
 655 static int scpi_probe(struct platform_device *pdev)
 656 {
 657         int count, idx, ret;
 658         struct resource res;
 659         struct scpi_chan *scpi_chan;
 660         struct device *dev = &pdev->dev;
 661         struct device_node *np = dev->of_node;
 662
 663         scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
 664         if (!scpi_info)
 665                 return -ENOMEM;
 666
 667         count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
 668         if (count < 0) {
 669                 dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
 670                 return -ENODEV;
 671         }
 672
 673         scpi_chan = devm_kcalloc(dev, count, sizeof(*scpi_chan), GFP_KERNEL);
 674         if (!scpi_chan)
 675                 return -ENOMEM;
 676
 677         for (idx = 0; idx < count; idx++) {
 678                 resource_size_t size;
 679                 struct scpi_chan *pchan = scpi_chan + idx;
 680                 struct mbox_client *cl = &pchan->cl;
 681                 struct device_node *shmem = of_parse_phandle(np, "shmem", idx);
 682
 683                 if (of_address_to_resource(shmem, 0, &res)) {
 684                         dev_err(dev, "failed to get SCPI payload mem resource\n");
 685                         ret = -EINVAL;
 686                         goto err;
 687                 }
 688
 689                 size = resource_size(&res);
 690                 pchan->rx_payload = devm_ioremap(dev, res.start, size);
 691                 if (!pchan->rx_payload) {
 692                         dev_err(dev, "failed to ioremap SCPI payload\n");
 693                         ret = -EADDRNOTAVAIL;
 694                         goto err;
 695                 }
 696                 pchan->tx_payload = pchan->rx_payload + (size >> 1);
 697
 698                 cl->dev = dev;
 699                 cl->rx_callback = scpi_handle_remote_msg;
 700                 cl->tx_prepare = scpi_tx_prepare;
 701                 cl->tx_block = true;
 702                 cl->tx_tout = 50;
 703                 cl->knows_txdone = false; /* controller can't ack */
 704
 705                 INIT_LIST_HEAD(&pchan->rx_pending);
 706                 INIT_LIST_HEAD(&pchan->xfers_list);
 707                 spin_lock_init(&pchan->rx_lock);
 708                 mutex_init(&pchan->xfers_lock);
 709
 710                 ret = scpi_alloc_xfer_list(dev, pchan);
 711                 if (!ret) {
 712                         pchan->chan = mbox_request_channel(cl, idx);
 713                         if (!IS_ERR(pchan->chan))
 714                                 continue;
 715                         ret = PTR_ERR(pchan->chan);
 716                         if (ret != -EPROBE_DEFER)
 717                                 dev_err(dev, "failed to get channel%d err %d\n",
 718                                         idx, ret);
 719                 }
 720 err:
 721                 scpi_free_channels(dev, scpi_chan, idx);
 722                 scpi_info = NULL;
 723                 return ret;
 724         }
 725
 726         scpi_info->channels = scpi_chan;
 727         scpi_info->num_chans = count;
 728         platform_set_drvdata(pdev, scpi_info);
 729
 730         ret = scpi_init_versions(scpi_info);
 731         if (ret) {
 732                 dev_err(dev, "incorrect or no SCP firmware found\n");
 733                 scpi_remove(pdev);
 734                 return ret;
 735         }
 736
 737         _dev_info(dev, "SCP Protocol %d.%d Firmware %d.%d.%d version\n",
 738                   PROTOCOL_REV_MAJOR(scpi_info->protocol_version),
 739                   PROTOCOL_REV_MINOR(scpi_info->protocol_version),
 740                   FW_REV_MAJOR(scpi_info->firmware_version),
 741                   FW_REV_MINOR(scpi_info->firmware_version),
 742                   FW_REV_PATCH(scpi_info->firmware_version));
 743         scpi_info->scpi_ops = &scpi_ops;
 744
 745         ret = sysfs_create_groups(&dev->kobj, versions_groups);
 746         if (ret)
 747                 dev_err(dev, "unable to create sysfs version group\n");
 748
 749         return of_platform_populate(dev->of_node, NULL, NULL, dev);
 750 }
 751
 752 static const struct of_device_id scpi_of_match[] = {
 753         {.compatible = "arm,scpi"},
 754         {},
 755 };
 756
 757 MODULE_DEVICE_TABLE(of, scpi_of_match);
 758
 759 static struct platform_driver scpi_driver = {
 760         .driver = {
 761                 .name = "scpi_protocol",
 762                 .of_match_table = scpi_of_match,
 763         },
 764         .probe = scpi_probe,
 765         .remove = scpi_remove,
 766 };
 767 module_platform_driver(scpi_driver);
 768
 769 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 770 MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
 771 MODULE_LICENSE("GPL v2");