linux/drivers/firmware/arm_scpi.c
<<
>>
Prefs
   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
  85enum 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
 102enum 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
 135struct 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
 147struct 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
 160struct 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 */
 174struct scpi_shared_mem {
 175        __le32 command;
 176        __le32 status;
 177        u8 payload[0];
 178} __packed;
 179
 180struct scp_capabilities {
 181        __le32 protocol_version;
 182        __le32 event_version;
 183        __le32 platform_version;
 184        __le32 commands[4];
 185} __packed;
 186
 187struct clk_get_info {
 188        __le16 id;
 189        __le16 flags;
 190        __le32 min_rate;
 191        __le32 max_rate;
 192        u8 name[20];
 193} __packed;
 194
 195struct clk_get_value {
 196        __le32 rate;
 197} __packed;
 198
 199struct clk_set_value {
 200        __le16 id;
 201        __le16 reserved;
 202        __le32 rate;
 203} __packed;
 204
 205struct dvfs_info {
 206        __le32 header;
 207        struct {
 208                __le32 freq;
 209                __le32 m_volt;
 210        } opps[MAX_DVFS_OPPS];
 211} __packed;
 212
 213struct dvfs_get {
 214        u8 index;
 215} __packed;
 216
 217struct dvfs_set {
 218        u8 domain;
 219        u8 index;
 220} __packed;
 221
 222struct sensor_capabilities {
 223        __le16 sensors;
 224} __packed;
 225
 226struct _scpi_sensor_info {
 227        __le16 sensor_id;
 228        u8 class;
 229        u8 trigger_type;
 230        char name[20];
 231};
 232
 233struct sensor_value {
 234        __le32 lo_val;
 235        __le32 hi_val;
 236} __packed;
 237
 238static struct scpi_drvinfo *scpi_info;
 239
 240static 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
 257static 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
 264static 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
 295static 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
 304static 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
 324static 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
 339static 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
 346static 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;
 378out:
 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
 387static u32 scpi_get_version(void)
 388{
 389        return scpi_info->protocol_version;
 390}
 391
 392static int
 393scpi_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
 408static 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
 419static 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
 431static 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
 441static 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
 450static 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
 457static 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
 500static 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
 513static 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
 529int 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
 544static 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
 557struct scpi_ops *get_scpi_ops(void)
 558{
 559        return scpi_info ? scpi_info->scpi_ops : NULL;
 560}
 561EXPORT_SYMBOL_GPL(get_scpi_ops);
 562
 563static 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
 577static 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}
 586static DEVICE_ATTR_RO(protocol_version);
 587
 588static 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}
 598static DEVICE_ATTR_RO(firmware_version);
 599
 600static struct attribute *versions_attrs[] = {
 601        &dev_attr_firmware_version.attr,
 602        &dev_attr_protocol_version.attr,
 603        NULL,
 604};
 605ATTRIBUTE_GROUPS(versions);
 606
 607static void
 608scpi_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
 619static 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
 643static 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
 658static 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                }
 723err:
 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
 755static const struct of_device_id scpi_of_match[] = {
 756        {.compatible = "arm,scpi"},
 757        {},
 758};
 759
 760MODULE_DEVICE_TABLE(of, scpi_of_match);
 761
 762static 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};
 770module_platform_driver(scpi_driver);
 771
 772MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
 773MODULE_DESCRIPTION("ARM SCPI mailbox protocol driver");
 774MODULE_LICENSE("GPL v2");
 775