drivers/macintosh/smu.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * PowerMac G5 SMU driver
   4  *
   5  * Copyright 2004 J. Mayer <l_indien@magic.fr>
   6  * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   7  */
   8
   9 /*
  10  * TODO:
  11  *  - maybe add timeout to commands ?
  12  *  - blocking version of time functions
  13  *  - polling version of i2c commands (including timer that works with
  14  *    interrupts off)
  15  *  - maybe avoid some data copies with i2c by directly using the smu cmd
  16  *    buffer and a lower level internal interface
  17  *  - understand SMU -> CPU events and implement reception of them via
  18  *    the userland interface
  19  */
  20
  21 #include <linux/types.h>
  22 #include <linux/kernel.h>
  23 #include <linux/device.h>
  24 #include <linux/dmapool.h>
  25 #include <linux/memblock.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/highmem.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/rtc.h>
  31 #include <linux/completion.h>
  32 #include <linux/miscdevice.h>
  33 #include <linux/delay.h>
  34 #include <linux/poll.h>
  35 #include <linux/mutex.h>
  36 #include <linux/of_device.h>
  37 #include <linux/of_irq.h>
  38 #include <linux/of_platform.h>
  39 #include <linux/slab.h>
  40 #include <linux/sched/signal.h>
  41
  42 #include <asm/byteorder.h>
  43 #include <asm/io.h>
  44 #include <asm/machdep.h>
  45 #include <asm/pmac_feature.h>
  46 #include <asm/smu.h>
  47 #include <asm/sections.h>
  48 #include <linux/uaccess.h>
  49
  50 #define VERSION "0.7"
  51 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  52
  53 #undef DEBUG_SMU
  54
  55 #ifdef DEBUG_SMU
  56 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  57 #else
  58 #define DPRINTK(fmt, args...) do { } while (0)
  59 #endif
  60
  61 /*
  62  * This is the command buffer passed to the SMU hardware
  63  */
  64 #define SMU_MAX_DATA    254
  65
  66 struct smu_cmd_buf {
  67         u8 cmd;
  68         u8 length;
  69         u8 data[SMU_MAX_DATA];
  70 };
  71
  72 struct smu_device {
  73         spinlock_t              lock;
  74         struct device_node      *of_node;
  75         struct platform_device  *of_dev;
  76         int                     doorbell;       /* doorbell gpio */
  77         u32 __iomem             *db_buf;        /* doorbell buffer */
  78         struct device_node      *db_node;
  79         unsigned int            db_irq;
  80         int                     msg;
  81         struct device_node      *msg_node;
  82         unsigned int            msg_irq;
  83         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
  84         u32                     cmd_buf_abs;    /* command buffer absolute */
  85         struct list_head        cmd_list;
  86         struct smu_cmd          *cmd_cur;       /* pending command */
  87         int                     broken_nap;
  88         struct list_head        cmd_i2c_list;
  89         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
  90         struct timer_list       i2c_timer;
  91 };
  92
  93 /*
  94  * I don't think there will ever be more than one SMU, so
  95  * for now, just hard code that
  96  */
  97 static DEFINE_MUTEX(smu_mutex);
  98 static struct smu_device        *smu;
  99 static DEFINE_MUTEX(smu_part_access);
 100 static int smu_irq_inited;
 101 static unsigned long smu_cmdbuf_abs;
 102
 103 static void smu_i2c_retry(struct timer_list *t);
 104
 105 /*
 106  * SMU driver low level stuff
 107  */
 108
 109 static void smu_start_cmd(void)
 110 {
 111         unsigned long faddr, fend;
 112         struct smu_cmd *cmd;
 113
 114         if (list_empty(&smu->cmd_list))
 115                 return;
 116
 117         /* Fetch first command in queue */
 118         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 119         smu->cmd_cur = cmd;
 120         list_del(&cmd->link);
 121
 122         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 123                 cmd->data_len);
 124         DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
 125
 126         /* Fill the SMU command buffer */
 127         smu->cmd_buf->cmd = cmd->cmd;
 128         smu->cmd_buf->length = cmd->data_len;
 129         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 130
 131         /* Flush command and data to RAM */
 132         faddr = (unsigned long)smu->cmd_buf;
 133         fend = faddr + smu->cmd_buf->length + 2;
 134         flush_dcache_range(faddr, fend);
 135
 136
 137         /* We also disable NAP mode for the duration of the command
 138          * on U3 based machines.
 139          * This is slightly racy as it can be written back to 1 by a sysctl
 140          * but that never happens in practice. There seem to be an issue with
 141          * U3 based machines such as the iMac G5 where napping for the
 142          * whole duration of the command prevents the SMU from fetching it
 143          * from memory. This might be related to the strange i2c based
 144          * mechanism the SMU uses to access memory.
 145          */
 146         if (smu->broken_nap)
 147                 powersave_nap = 0;
 148
 149         /* This isn't exactly a DMA mapping here, I suspect
 150          * the SMU is actually communicating with us via i2c to the
 151          * northbridge or the CPU to access RAM.
 152          */
 153         writel(smu->cmd_buf_abs, smu->db_buf);
 154
 155         /* Ring the SMU doorbell */
 156         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 157 }
 158
 159
 160 static irqreturn_t smu_db_intr(int irq, void *arg)
 161 {
 162         unsigned long flags;
 163         struct smu_cmd *cmd;
 164         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 165         void *misc = NULL;
 166         u8 gpio;
 167         int rc = 0;
 168
 169         /* SMU completed the command, well, we hope, let's make sure
 170          * of it
 171          */
 172         spin_lock_irqsave(&smu->lock, flags);
 173
 174         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 175         if ((gpio & 7) != 7) {
 176                 spin_unlock_irqrestore(&smu->lock, flags);
 177                 return IRQ_HANDLED;
 178         }
 179
 180         cmd = smu->cmd_cur;
 181         smu->cmd_cur = NULL;
 182         if (cmd == NULL)
 183                 goto bail;
 184
 185         if (rc == 0) {
 186                 unsigned long faddr;
 187                 int reply_len;
 188                 u8 ack;
 189
 190                 /* CPU might have brought back the cache line, so we need
 191                  * to flush again before peeking at the SMU response. We
 192                  * flush the entire buffer for now as we haven't read the
 193                  * reply length (it's only 2 cache lines anyway)
 194                  */
 195                 faddr = (unsigned long)smu->cmd_buf;
 196                 flush_dcache_range(faddr, faddr + 256);
 197
 198                 /* Now check ack */
 199                 ack = (~cmd->cmd) & 0xff;
 200                 if (ack != smu->cmd_buf->cmd) {
 201                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
 202                                 ack, smu->cmd_buf->cmd);
 203                         rc = -EIO;
 204                 }
 205                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 206                 DPRINTK("SMU: reply len: %d\n", reply_len);
 207                 if (reply_len > cmd->reply_len) {
 208                         printk(KERN_WARNING "SMU: reply buffer too small,"
 209                                "got %d bytes for a %d bytes buffer\n",
 210                                reply_len, cmd->reply_len);
 211                         reply_len = cmd->reply_len;
 212                 }
 213                 cmd->reply_len = reply_len;
 214                 if (cmd->reply_buf && reply_len)
 215                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 216         }
 217
 218         /* Now complete the command. Write status last in order as we lost
 219          * ownership of the command structure as soon as it's no longer -1
 220          */
 221         done = cmd->done;
 222         misc = cmd->misc;
 223         mb();
 224         cmd->status = rc;
 225
 226         /* Re-enable NAP mode */
 227         if (smu->broken_nap)
 228                 powersave_nap = 1;
 229  bail:
 230         /* Start next command if any */
 231         smu_start_cmd();
 232         spin_unlock_irqrestore(&smu->lock, flags);
 233
 234         /* Call command completion handler if any */
 235         if (done)
 236                 done(cmd, misc);
 237
 238         /* It's an edge interrupt, nothing to do */
 239         return IRQ_HANDLED;
 240 }
 241
 242
 243 static irqreturn_t smu_msg_intr(int irq, void *arg)
 244 {
 245         /* I don't quite know what to do with this one, we seem to never
 246          * receive it, so I suspect we have to arm it someway in the SMU
 247          * to start getting events that way.
 248          */
 249
 250         printk(KERN_INFO "SMU: message interrupt !\n");
 251
 252         /* It's an edge interrupt, nothing to do */
 253         return IRQ_HANDLED;
 254 }
 255
 256
 257 /*
 258  * Queued command management.
 259  *
 260  */
 261
 262 int smu_queue_cmd(struct smu_cmd *cmd)
 263 {
 264         unsigned long flags;
 265
 266         if (smu == NULL)
 267                 return -ENODEV;
 268         if (cmd->data_len > SMU_MAX_DATA ||
 269             cmd->reply_len > SMU_MAX_DATA)
 270                 return -EINVAL;
 271
 272         cmd->status = 1;
 273         spin_lock_irqsave(&smu->lock, flags);
 274         list_add_tail(&cmd->link, &smu->cmd_list);
 275         if (smu->cmd_cur == NULL)
 276                 smu_start_cmd();
 277         spin_unlock_irqrestore(&smu->lock, flags);
 278
 279         /* Workaround for early calls when irq isn't available */
 280         if (!smu_irq_inited || !smu->db_irq)
 281                 smu_spinwait_cmd(cmd);
 282
 283         return 0;
 284 }
 285 EXPORT_SYMBOL(smu_queue_cmd);
 286
 287
 288 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 289                      unsigned int data_len,
 290                      void (*done)(struct smu_cmd *cmd, void *misc),
 291                      void *misc, ...)
 292 {
 293         struct smu_cmd *cmd = &scmd->cmd;
 294         va_list list;
 295         int i;
 296
 297         if (data_len > sizeof(scmd->buffer))
 298                 return -EINVAL;
 299
 300         memset(scmd, 0, sizeof(*scmd));
 301         cmd->cmd = command;
 302         cmd->data_len = data_len;
 303         cmd->data_buf = scmd->buffer;
 304         cmd->reply_len = sizeof(scmd->buffer);
 305         cmd->reply_buf = scmd->buffer;
 306         cmd->done = done;
 307         cmd->misc = misc;
 308
 309         va_start(list, misc);
 310         for (i = 0; i < data_len; ++i)
 311                 scmd->buffer[i] = (u8)va_arg(list, int);
 312         va_end(list);
 313
 314         return smu_queue_cmd(cmd);
 315 }
 316 EXPORT_SYMBOL(smu_queue_simple);
 317
 318
 319 void smu_poll(void)
 320 {
 321         u8 gpio;
 322
 323         if (smu == NULL)
 324                 return;
 325
 326         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 327         if ((gpio & 7) == 7)
 328                 smu_db_intr(smu->db_irq, smu);
 329 }
 330 EXPORT_SYMBOL(smu_poll);
 331
 332
 333 void smu_done_complete(struct smu_cmd *cmd, void *misc)
 334 {
 335         struct completion *comp = misc;
 336
 337         complete(comp);
 338 }
 339 EXPORT_SYMBOL(smu_done_complete);
 340
 341
 342 void smu_spinwait_cmd(struct smu_cmd *cmd)
 343 {
 344         while(cmd->status == 1)
 345                 smu_poll();
 346 }
 347 EXPORT_SYMBOL(smu_spinwait_cmd);
 348
 349
 350 /* RTC low level commands */
 351 static inline int bcd2hex (int n)
 352 {
 353         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 354 }
 355
 356
 357 static inline int hex2bcd (int n)
 358 {
 359         return ((n / 10) << 4) + (n % 10);
 360 }
 361
 362
 363 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 364                                         struct rtc_time *time)
 365 {
 366         cmd_buf->cmd = 0x8e;
 367         cmd_buf->length = 8;
 368         cmd_buf->data[0] = 0x80;
 369         cmd_buf->data[1] = hex2bcd(time->tm_sec);
 370         cmd_buf->data[2] = hex2bcd(time->tm_min);
 371         cmd_buf->data[3] = hex2bcd(time->tm_hour);
 372         cmd_buf->data[4] = time->tm_wday;
 373         cmd_buf->data[5] = hex2bcd(time->tm_mday);
 374         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 375         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 376 }
 377
 378
 379 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 380 {
 381         struct smu_simple_cmd cmd;
 382         int rc;
 383
 384         if (smu == NULL)
 385                 return -ENODEV;
 386
 387         memset(time, 0, sizeof(struct rtc_time));
 388         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 389                               SMU_CMD_RTC_GET_DATETIME);
 390         if (rc)
 391                 return rc;
 392         smu_spinwait_simple(&cmd);
 393
 394         time->tm_sec = bcd2hex(cmd.buffer[0]);
 395         time->tm_min = bcd2hex(cmd.buffer[1]);
 396         time->tm_hour = bcd2hex(cmd.buffer[2]);
 397         time->tm_wday = bcd2hex(cmd.buffer[3]);
 398         time->tm_mday = bcd2hex(cmd.buffer[4]);
 399         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 400         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 401
 402         return 0;
 403 }
 404
 405
 406 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 407 {
 408         struct smu_simple_cmd cmd;
 409         int rc;
 410
 411         if (smu == NULL)
 412                 return -ENODEV;
 413
 414         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 415                               SMU_CMD_RTC_SET_DATETIME,
 416                               hex2bcd(time->tm_sec),
 417                               hex2bcd(time->tm_min),
 418                               hex2bcd(time->tm_hour),
 419                               time->tm_wday,
 420                               hex2bcd(time->tm_mday),
 421                               hex2bcd(time->tm_mon) + 1,
 422                               hex2bcd(time->tm_year - 100));
 423         if (rc)
 424                 return rc;
 425         smu_spinwait_simple(&cmd);
 426
 427         return 0;
 428 }
 429
 430
 431 void smu_shutdown(void)
 432 {
 433         struct smu_simple_cmd cmd;
 434
 435         if (smu == NULL)
 436                 return;
 437
 438         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 439                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 440                 return;
 441         smu_spinwait_simple(&cmd);
 442         for (;;)
 443                 ;
 444 }
 445
 446
 447 void smu_restart(void)
 448 {
 449         struct smu_simple_cmd cmd;
 450
 451         if (smu == NULL)
 452                 return;
 453
 454         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 455                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 456                 return;
 457         smu_spinwait_simple(&cmd);
 458         for (;;)
 459                 ;
 460 }
 461
 462
 463 int smu_present(void)
 464 {
 465         return smu != NULL;
 466 }
 467 EXPORT_SYMBOL(smu_present);
 468
 469
 470 int __init smu_init (void)
 471 {
 472         struct device_node *np;
 473         const u32 *data;
 474         int ret = 0;
 475
 476         np = of_find_node_by_type(NULL, "smu");
 477         if (np == NULL)
 478                 return -ENODEV;
 479
 480         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 481
 482         /*
 483          * SMU based G5s need some memory below 2Gb. Thankfully this is
 484          * called at a time where memblock is still available.
 485          */
 486         smu_cmdbuf_abs = memblock_phys_alloc_range(4096, 4096, 0, 0x80000000UL);
 487         if (smu_cmdbuf_abs == 0) {
 488                 printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
 489                 ret = -EINVAL;
 490                 goto fail_np;
 491         }
 492
 493         smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES);
 494         if (!smu)
 495                 panic("%s: Failed to allocate %zu bytes\n", __func__,
 496                       sizeof(struct smu_device));
 497
 498         spin_lock_init(&smu->lock);
 499         INIT_LIST_HEAD(&smu->cmd_list);
 500         INIT_LIST_HEAD(&smu->cmd_i2c_list);
 501         smu->of_node = np;
 502         smu->db_irq = 0;
 503         smu->msg_irq = 0;
 504
 505         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 506          * 32 bits value safely
 507          */
 508         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 509         smu->cmd_buf = __va(smu_cmdbuf_abs);
 510
 511         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 512         if (smu->db_node == NULL) {
 513                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 514                 ret = -ENXIO;
 515                 goto fail_bootmem;
 516         }
 517         data = of_get_property(smu->db_node, "reg", NULL);
 518         if (data == NULL) {
 519                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 520                 ret = -ENXIO;
 521                 goto fail_db_node;
 522         }
 523
 524         /* Current setup has one doorbell GPIO that does both doorbell
 525          * and ack. GPIOs are at 0x50, best would be to find that out
 526          * in the device-tree though.
 527          */
 528         smu->doorbell = *data;
 529         if (smu->doorbell < 0x50)
 530                 smu->doorbell += 0x50;
 531
 532         /* Now look for the smu-interrupt GPIO */
 533         do {
 534                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 535                 if (smu->msg_node == NULL)
 536                         break;
 537                 data = of_get_property(smu->msg_node, "reg", NULL);
 538                 if (data == NULL) {
 539                         of_node_put(smu->msg_node);
 540                         smu->msg_node = NULL;
 541                         break;
 542                 }
 543                 smu->msg = *data;
 544                 if (smu->msg < 0x50)
 545                         smu->msg += 0x50;
 546         } while(0);
 547
 548         /* Doorbell buffer is currently hard-coded, I didn't find a proper
 549          * device-tree entry giving the address. Best would probably to use
 550          * an offset for K2 base though, but let's do it that way for now.
 551          */
 552         smu->db_buf = ioremap(0x8000860c, 0x1000);
 553         if (smu->db_buf == NULL) {
 554                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 555                 ret = -ENXIO;
 556                 goto fail_msg_node;
 557         }
 558
 559         /* U3 has an issue with NAP mode when issuing SMU commands */
 560         smu->broken_nap = pmac_get_uninorth_variant() < 4;
 561         if (smu->broken_nap)
 562                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
 563
 564         sys_ctrler = SYS_CTRLER_SMU;
 565         return 0;
 566
 567 fail_msg_node:
 568         of_node_put(smu->msg_node);
 569 fail_db_node:
 570         of_node_put(smu->db_node);
 571 fail_bootmem:
 572         memblock_free(smu, sizeof(struct smu_device));
 573         smu = NULL;
 574 fail_np:
 575         of_node_put(np);
 576         return ret;
 577 }
 578
 579
 580 static int smu_late_init(void)
 581 {
 582         if (!smu)
 583                 return 0;
 584
 585         timer_setup(&smu->i2c_timer, smu_i2c_retry, 0);
 586
 587         if (smu->db_node) {
 588                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 589                 if (!smu->db_irq)
 590                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 591                                smu->db_node);
 592         }
 593         if (smu->msg_node) {
 594                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 595                 if (!smu->msg_irq)
 596                         printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
 597                                smu->msg_node);
 598         }
 599
 600         /*
 601          * Try to request the interrupts
 602          */
 603
 604         if (smu->db_irq) {
 605                 if (request_irq(smu->db_irq, smu_db_intr,
 606                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
 607                         printk(KERN_WARNING "SMU: can't "
 608                                "request interrupt %d\n",
 609                                smu->db_irq);
 610                         smu->db_irq = 0;
 611                 }
 612         }
 613
 614         if (smu->msg_irq) {
 615                 if (request_irq(smu->msg_irq, smu_msg_intr,
 616                                 IRQF_SHARED, "SMU message", smu) < 0) {
 617                         printk(KERN_WARNING "SMU: can't "
 618                                "request interrupt %d\n",
 619                                smu->msg_irq);
 620                         smu->msg_irq = 0;
 621                 }
 622         }
 623
 624         smu_irq_inited = 1;
 625         return 0;
 626 }
 627 /* This has to be before arch_initcall as the low i2c stuff relies on the
 628  * above having been done before we reach arch_initcalls
 629  */
 630 core_initcall(smu_late_init);
 631
 632 /*
 633  * sysfs visibility
 634  */
 635
 636 static void smu_expose_childs(struct work_struct *unused)
 637 {
 638         struct device_node *np;
 639
 640         for_each_child_of_node(smu->of_node, np)
 641                 if (of_device_is_compatible(np, "smu-sensors"))
 642                         of_platform_device_create(np, "smu-sensors",
 643                                                   &smu->of_dev->dev);
 644 }
 645
 646 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 647
 648 static int smu_platform_probe(struct platform_device* dev)
 649 {
 650         if (!smu)
 651                 return -ENODEV;
 652         smu->of_dev = dev;
 653
 654         /*
 655          * Ok, we are matched, now expose all i2c busses. We have to defer
 656          * that unfortunately or it would deadlock inside the device model
 657          */
 658         schedule_work(&smu_expose_childs_work);
 659
 660         return 0;
 661 }
 662
 663 static const struct of_device_id smu_platform_match[] =
 664 {
 665         {
 666                 .type           = "smu",
 667         },
 668         {},
 669 };
 670
 671 static struct platform_driver smu_of_platform_driver =
 672 {
 673         .driver = {
 674                 .name = "smu",
 675                 .of_match_table = smu_platform_match,
 676         },
 677         .probe          = smu_platform_probe,
 678 };
 679
 680 static int __init smu_init_sysfs(void)
 681 {
 682         /*
 683          * For now, we don't power manage machines with an SMU chip,
 684          * I'm a bit too far from figuring out how that works with those
 685          * new chipsets, but that will come back and bite us
 686          */
 687         platform_driver_register(&smu_of_platform_driver);
 688         return 0;
 689 }
 690
 691 device_initcall(smu_init_sysfs);
 692
 693 struct platform_device *smu_get_ofdev(void)
 694 {
 695         if (!smu)
 696                 return NULL;
 697         return smu->of_dev;
 698 }
 699
 700 EXPORT_SYMBOL_GPL(smu_get_ofdev);
 701
 702 /*
 703  * i2c interface
 704  */
 705
 706 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 707 {
 708         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 709         void *misc = cmd->misc;
 710         unsigned long flags;
 711
 712         /* Check for read case */
 713         if (!fail && cmd->read) {
 714                 if (cmd->pdata[0] < 1)
 715                         fail = 1;
 716                 else
 717                         memcpy(cmd->info.data, &cmd->pdata[1],
 718                                cmd->info.datalen);
 719         }
 720
 721         DPRINTK("SMU: completing, success: %d\n", !fail);
 722
 723         /* Update status and mark no pending i2c command with lock
 724          * held so nobody comes in while we dequeue an eventual
 725          * pending next i2c command
 726          */
 727         spin_lock_irqsave(&smu->lock, flags);
 728         smu->cmd_i2c_cur = NULL;
 729         wmb();
 730         cmd->status = fail ? -EIO : 0;
 731
 732         /* Is there another i2c command waiting ? */
 733         if (!list_empty(&smu->cmd_i2c_list)) {
 734                 struct smu_i2c_cmd *newcmd;
 735
 736                 /* Fetch it, new current, remove from list */
 737                 newcmd = list_entry(smu->cmd_i2c_list.next,
 738                                     struct smu_i2c_cmd, link);
 739                 smu->cmd_i2c_cur = newcmd;
 740                 list_del(&cmd->link);
 741
 742                 /* Queue with low level smu */
 743                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 744                 if (smu->cmd_cur == NULL)
 745                         smu_start_cmd();
 746         }
 747         spin_unlock_irqrestore(&smu->lock, flags);
 748
 749         /* Call command completion handler if any */
 750         if (done)
 751                 done(cmd, misc);
 752
 753 }
 754
 755
 756 static void smu_i2c_retry(struct timer_list *unused)
 757 {
 758         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 759
 760         DPRINTK("SMU: i2c failure, requeuing...\n");
 761
 762         /* requeue command simply by resetting reply_len */
 763         cmd->pdata[0] = 0xff;
 764         cmd->scmd.reply_len = sizeof(cmd->pdata);
 765         smu_queue_cmd(&cmd->scmd);
 766 }
 767
 768
 769 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 770 {
 771         struct smu_i2c_cmd      *cmd = misc;
 772         int                     fail = 0;
 773
 774         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 775                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 776
 777         /* Check for possible status */
 778         if (scmd->status < 0)
 779                 fail = 1;
 780         else if (cmd->read) {
 781                 if (cmd->stage == 0)
 782                         fail = cmd->pdata[0] != 0;
 783                 else
 784                         fail = cmd->pdata[0] >= 0x80;
 785         } else {
 786                 fail = cmd->pdata[0] != 0;
 787         }
 788
 789         /* Handle failures by requeuing command, after 5ms interval
 790          */
 791         if (fail && --cmd->retries > 0) {
 792                 DPRINTK("SMU: i2c failure, starting timer...\n");
 793                 BUG_ON(cmd != smu->cmd_i2c_cur);
 794                 if (!smu_irq_inited) {
 795                         mdelay(5);
 796                         smu_i2c_retry(NULL);
 797                         return;
 798                 }
 799                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 800                 return;
 801         }
 802
 803         /* If failure or stage 1, command is complete */
 804         if (fail || cmd->stage != 0) {
 805                 smu_i2c_complete_command(cmd, fail);
 806                 return;
 807         }
 808
 809         DPRINTK("SMU: going to stage 1\n");
 810
 811         /* Ok, initial command complete, now poll status */
 812         scmd->reply_buf = cmd->pdata;
 813         scmd->reply_len = sizeof(cmd->pdata);
 814         scmd->data_buf = cmd->pdata;
 815         scmd->data_len = 1;
 816         cmd->pdata[0] = 0;
 817         cmd->stage = 1;
 818         cmd->retries = 20;
 819         smu_queue_cmd(scmd);
 820 }
 821
 822
 823 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 824 {
 825         unsigned long flags;
 826
 827         if (smu == NULL)
 828                 return -ENODEV;
 829
 830         /* Fill most fields of scmd */
 831         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 832         cmd->scmd.done = smu_i2c_low_completion;
 833         cmd->scmd.misc = cmd;
 834         cmd->scmd.reply_buf = cmd->pdata;
 835         cmd->scmd.reply_len = sizeof(cmd->pdata);
 836         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 837         cmd->scmd.status = 1;
 838         cmd->stage = 0;
 839         cmd->pdata[0] = 0xff;
 840         cmd->retries = 20;
 841         cmd->status = 1;
 842
 843         /* Check transfer type, sanitize some "info" fields
 844          * based on transfer type and do more checking
 845          */
 846         cmd->info.caddr = cmd->info.devaddr;
 847         cmd->read = cmd->info.devaddr & 0x01;
 848         switch(cmd->info.type) {
 849         case SMU_I2C_TRANSFER_SIMPLE:
 850                 cmd->info.sublen = 0;
 851                 memset(cmd->info.subaddr, 0, sizeof(cmd->info.subaddr));
 852                 break;
 853         case SMU_I2C_TRANSFER_COMBINED:
 854                 cmd->info.devaddr &= 0xfe;
 855                 fallthrough;
 856         case SMU_I2C_TRANSFER_STDSUB:
 857                 if (cmd->info.sublen > 3)
 858                         return -EINVAL;
 859                 break;
 860         default:
 861                 return -EINVAL;
 862         }
 863
 864         /* Finish setting up command based on transfer direction
 865          */
 866         if (cmd->read) {
 867                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
 868                         return -EINVAL;
 869                 memset(cmd->info.data, 0xff, cmd->info.datalen);
 870                 cmd->scmd.data_len = 9;
 871         } else {
 872                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 873                         return -EINVAL;
 874                 cmd->scmd.data_len = 9 + cmd->info.datalen;
 875         }
 876
 877         DPRINTK("SMU: i2c enqueuing command\n");
 878         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 879                 cmd->read ? "read" : "write", cmd->info.datalen,
 880                 cmd->info.bus, cmd->info.caddr,
 881                 cmd->info.subaddr[0], cmd->info.type);
 882
 883
 884         /* Enqueue command in i2c list, and if empty, enqueue also in
 885          * main command list
 886          */
 887         spin_lock_irqsave(&smu->lock, flags);
 888         if (smu->cmd_i2c_cur == NULL) {
 889                 smu->cmd_i2c_cur = cmd;
 890                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 891                 if (smu->cmd_cur == NULL)
 892                         smu_start_cmd();
 893         } else
 894                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 895         spin_unlock_irqrestore(&smu->lock, flags);
 896
 897         return 0;
 898 }
 899
 900 /*
 901  * Handling of "partitions"
 902  */
 903
 904 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 905 {
 906         DECLARE_COMPLETION_ONSTACK(comp);
 907         unsigned int chunk;
 908         struct smu_cmd cmd;
 909         int rc;
 910         u8 params[8];
 911
 912         /* We currently use a chunk size of 0xe. We could check the
 913          * SMU firmware version and use bigger sizes though
 914          */
 915         chunk = 0xe;
 916
 917         while (len) {
 918                 unsigned int clen = min(len, chunk);
 919
 920                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 921                 cmd.data_len = 7;
 922                 cmd.data_buf = params;
 923                 cmd.reply_len = chunk;
 924                 cmd.reply_buf = dest;
 925                 cmd.done = smu_done_complete;
 926                 cmd.misc = &comp;
 927                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 928                 params[1] = 0x4;
 929                 *((u32 *)&params[2]) = addr;
 930                 params[6] = clen;
 931
 932                 rc = smu_queue_cmd(&cmd);
 933                 if (rc)
 934                         return rc;
 935                 wait_for_completion(&comp);
 936                 if (cmd.status != 0)
 937                         return rc;
 938                 if (cmd.reply_len != clen) {
 939                         printk(KERN_DEBUG "SMU: short read in "
 940                                "smu_read_datablock, got: %d, want: %d\n",
 941                                cmd.reply_len, clen);
 942                         return -EIO;
 943                 }
 944                 len -= clen;
 945                 addr += clen;
 946                 dest += clen;
 947         }
 948         return 0;
 949 }
 950
 951 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 952 {
 953         DECLARE_COMPLETION_ONSTACK(comp);
 954         struct smu_simple_cmd cmd;
 955         unsigned int addr, len, tlen;
 956         struct smu_sdbp_header *hdr;
 957         struct property *prop;
 958
 959         /* First query the partition info */
 960         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 961         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 962                          smu_done_complete, &comp,
 963                          SMU_CMD_PARTITION_LATEST, id);
 964         wait_for_completion(&comp);
 965         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 966                 cmd.cmd.status, cmd.cmd.reply_len);
 967
 968         /* Partition doesn't exist (or other error) */
 969         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 970                 return NULL;
 971
 972         /* Fetch address and length from reply */
 973         addr = *((u16 *)cmd.buffer);
 974         len = cmd.buffer[3] << 2;
 975         /* Calucluate total length to allocate, including the 17 bytes
 976          * for "sdb-partition-XX" that we append at the end of the buffer
 977          */
 978         tlen = sizeof(struct property) + len + 18;
 979
 980         prop = kzalloc(tlen, GFP_KERNEL);
 981         if (prop == NULL)
 982                 return NULL;
 983         hdr = (struct smu_sdbp_header *)(prop + 1);
 984         prop->name = ((char *)prop) + tlen - 18;
 985         sprintf(prop->name, "sdb-partition-%02x", id);
 986         prop->length = len;
 987         prop->value = hdr;
 988         prop->next = NULL;
 989
 990         /* Read the datablock */
 991         if (smu_read_datablock((u8 *)hdr, addr, len)) {
 992                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
 993                        "partition %02x !\n", id);
 994                 goto failure;
 995         }
 996
 997         /* Got it, check a few things and create the property */
 998         if (hdr->id != id) {
 999                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1000                        "%02x !\n", id, hdr->id);
1001                 goto failure;
1002         }
1003         if (of_add_property(smu->of_node, prop)) {
1004                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1005                        "property !\n", id);
1006                 goto failure;
1007         }
1008
1009         return hdr;
1010  failure:
1011         kfree(prop);
1012         return NULL;
1013 }
1014
1015 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1016  * when interruptible is 1
1017  */
1018 static const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1019                 unsigned int *size, int interruptible)
1020 {
1021         char pname[32];
1022         const struct smu_sdbp_header *part;
1023
1024         if (!smu)
1025                 return NULL;
1026
1027         sprintf(pname, "sdb-partition-%02x", id);
1028
1029         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1030
1031         if (interruptible) {
1032                 int rc;
1033                 rc = mutex_lock_interruptible(&smu_part_access);
1034                 if (rc)
1035                         return ERR_PTR(rc);
1036         } else
1037                 mutex_lock(&smu_part_access);
1038
1039         part = of_get_property(smu->of_node, pname, size);
1040         if (part == NULL) {
1041                 DPRINTK("trying to extract from SMU ...\n");
1042                 part = smu_create_sdb_partition(id);
1043                 if (part != NULL && size)
1044                         *size = part->len << 2;
1045         }
1046         mutex_unlock(&smu_part_access);
1047         return part;
1048 }
1049
1050 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1051 {
1052         return __smu_get_sdb_partition(id, size, 0);
1053 }
1054 EXPORT_SYMBOL(smu_get_sdb_partition);
1055
1056
1057 /*
1058  * Userland driver interface
1059  */
1060
1061
1062 static LIST_HEAD(smu_clist);
1063 static DEFINE_SPINLOCK(smu_clist_lock);
1064
1065 enum smu_file_mode {
1066         smu_file_commands,
1067         smu_file_events,
1068         smu_file_closing
1069 };
1070
1071 struct smu_private
1072 {
1073         struct list_head        list;
1074         enum smu_file_mode      mode;
1075         int                     busy;
1076         struct smu_cmd          cmd;
1077         spinlock_t              lock;
1078         wait_queue_head_t       wait;
1079         u8                      buffer[SMU_MAX_DATA];
1080 };
1081
1082
1083 static int smu_open(struct inode *inode, struct file *file)
1084 {
1085         struct smu_private *pp;
1086         unsigned long flags;
1087
1088         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1089         if (!pp)
1090                 return -ENOMEM;
1091         spin_lock_init(&pp->lock);
1092         pp->mode = smu_file_commands;
1093         init_waitqueue_head(&pp->wait);
1094
1095         mutex_lock(&smu_mutex);
1096         spin_lock_irqsave(&smu_clist_lock, flags);
1097         list_add(&pp->list, &smu_clist);
1098         spin_unlock_irqrestore(&smu_clist_lock, flags);
1099         file->private_data = pp;
1100         mutex_unlock(&smu_mutex);
1101
1102         return 0;
1103 }
1104
1105
1106 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1107 {
1108         struct smu_private *pp = misc;
1109
1110         wake_up_all(&pp->wait);
1111 }
1112
1113
1114 static ssize_t smu_write(struct file *file, const char __user *buf,
1115                          size_t count, loff_t *ppos)
1116 {
1117         struct smu_private *pp = file->private_data;
1118         unsigned long flags;
1119         struct smu_user_cmd_hdr hdr;
1120         int rc = 0;
1121
1122         if (pp->busy)
1123                 return -EBUSY;
1124         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1125                 return -EFAULT;
1126         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1127                 pp->mode = smu_file_events;
1128                 return 0;
1129         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1130                 const struct smu_sdbp_header *part;
1131                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1132                 if (part == NULL)
1133                         return -EINVAL;
1134                 else if (IS_ERR(part))
1135                         return PTR_ERR(part);
1136                 return 0;
1137         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1138                 return -EINVAL;
1139         else if (pp->mode != smu_file_commands)
1140                 return -EBADFD;
1141         else if (hdr.data_len > SMU_MAX_DATA)
1142                 return -EINVAL;
1143
1144         spin_lock_irqsave(&pp->lock, flags);
1145         if (pp->busy) {
1146                 spin_unlock_irqrestore(&pp->lock, flags);
1147                 return -EBUSY;
1148         }
1149         pp->busy = 1;
1150         pp->cmd.status = 1;
1151         spin_unlock_irqrestore(&pp->lock, flags);
1152
1153         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1154                 pp->busy = 0;
1155                 return -EFAULT;
1156         }
1157
1158         pp->cmd.cmd = hdr.cmd;
1159         pp->cmd.data_len = hdr.data_len;
1160         pp->cmd.reply_len = SMU_MAX_DATA;
1161         pp->cmd.data_buf = pp->buffer;
1162         pp->cmd.reply_buf = pp->buffer;
1163         pp->cmd.done = smu_user_cmd_done;
1164         pp->cmd.misc = pp;
1165         rc = smu_queue_cmd(&pp->cmd);
1166         if (rc < 0)
1167                 return rc;
1168         return count;
1169 }
1170
1171
1172 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1173                                 char __user *buf, size_t count)
1174 {
1175         DECLARE_WAITQUEUE(wait, current);
1176         struct smu_user_reply_hdr hdr;
1177         unsigned long flags;
1178         int size, rc = 0;
1179
1180         if (!pp->busy)
1181                 return 0;
1182         if (count < sizeof(struct smu_user_reply_hdr))
1183                 return -EOVERFLOW;
1184         spin_lock_irqsave(&pp->lock, flags);
1185         if (pp->cmd.status == 1) {
1186                 if (file->f_flags & O_NONBLOCK) {
1187                         spin_unlock_irqrestore(&pp->lock, flags);
1188                         return -EAGAIN;
1189                 }
1190                 add_wait_queue(&pp->wait, &wait);
1191                 for (;;) {
1192                         set_current_state(TASK_INTERRUPTIBLE);
1193                         rc = 0;
1194                         if (pp->cmd.status != 1)
1195                                 break;
1196                         rc = -ERESTARTSYS;
1197                         if (signal_pending(current))
1198                                 break;
1199                         spin_unlock_irqrestore(&pp->lock, flags);
1200                         schedule();
1201                         spin_lock_irqsave(&pp->lock, flags);
1202                 }
1203                 set_current_state(TASK_RUNNING);
1204                 remove_wait_queue(&pp->wait, &wait);
1205         }
1206         spin_unlock_irqrestore(&pp->lock, flags);
1207         if (rc)
1208                 return rc;
1209         if (pp->cmd.status != 0)
1210                 pp->cmd.reply_len = 0;
1211         size = sizeof(hdr) + pp->cmd.reply_len;
1212         if (count < size)
1213                 size = count;
1214         rc = size;
1215         hdr.status = pp->cmd.status;
1216         hdr.reply_len = pp->cmd.reply_len;
1217         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1218                 return -EFAULT;
1219         size -= sizeof(hdr);
1220         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1221                 return -EFAULT;
1222         pp->busy = 0;
1223
1224         return rc;
1225 }
1226
1227
1228 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1229                                char __user *buf, size_t count)
1230 {
1231         /* Not implemented */
1232         msleep_interruptible(1000);
1233         return 0;
1234 }
1235
1236
1237 static ssize_t smu_read(struct file *file, char __user *buf,
1238                         size_t count, loff_t *ppos)
1239 {
1240         struct smu_private *pp = file->private_data;
1241
1242         if (pp->mode == smu_file_commands)
1243                 return smu_read_command(file, pp, buf, count);
1244         if (pp->mode == smu_file_events)
1245                 return smu_read_events(file, pp, buf, count);
1246
1247         return -EBADFD;
1248 }
1249
1250 static __poll_t smu_fpoll(struct file *file, poll_table *wait)
1251 {
1252         struct smu_private *pp = file->private_data;
1253         __poll_t mask = 0;
1254         unsigned long flags;
1255
1256         if (!pp)
1257                 return 0;
1258
1259         if (pp->mode == smu_file_commands) {
1260                 poll_wait(file, &pp->wait, wait);
1261
1262                 spin_lock_irqsave(&pp->lock, flags);
1263                 if (pp->busy && pp->cmd.status != 1)
1264                         mask |= EPOLLIN;
1265                 spin_unlock_irqrestore(&pp->lock, flags);
1266         }
1267         if (pp->mode == smu_file_events) {
1268                 /* Not yet implemented */
1269         }
1270         return mask;
1271 }
1272
1273 static int smu_release(struct inode *inode, struct file *file)
1274 {
1275         struct smu_private *pp = file->private_data;
1276         unsigned long flags;
1277         unsigned int busy;
1278
1279         if (!pp)
1280                 return 0;
1281
1282         file->private_data = NULL;
1283
1284         /* Mark file as closing to avoid races with new request */
1285         spin_lock_irqsave(&pp->lock, flags);
1286         pp->mode = smu_file_closing;
1287         busy = pp->busy;
1288
1289         /* Wait for any pending request to complete */
1290         if (busy && pp->cmd.status == 1) {
1291                 DECLARE_WAITQUEUE(wait, current);
1292
1293                 add_wait_queue(&pp->wait, &wait);
1294                 for (;;) {
1295                         set_current_state(TASK_UNINTERRUPTIBLE);
1296                         if (pp->cmd.status != 1)
1297                                 break;
1298                         spin_unlock_irqrestore(&pp->lock, flags);
1299                         schedule();
1300                         spin_lock_irqsave(&pp->lock, flags);
1301                 }
1302                 set_current_state(TASK_RUNNING);
1303                 remove_wait_queue(&pp->wait, &wait);
1304         }
1305         spin_unlock_irqrestore(&pp->lock, flags);
1306
1307         spin_lock_irqsave(&smu_clist_lock, flags);
1308         list_del(&pp->list);
1309         spin_unlock_irqrestore(&smu_clist_lock, flags);
1310         kfree(pp);
1311
1312         return 0;
1313 }
1314
1315
1316 static const struct file_operations smu_device_fops = {
1317         .llseek         = no_llseek,
1318         .read           = smu_read,
1319         .write          = smu_write,
1320         .poll           = smu_fpoll,
1321         .open           = smu_open,
1322         .release        = smu_release,
1323 };
1324
1325 static struct miscdevice pmu_device = {
1326         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1327 };
1328
1329 static int smu_device_init(void)
1330 {
1331         if (!smu)
1332                 return -ENODEV;
1333         if (misc_register(&pmu_device) < 0)
1334                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1335         return 0;
1336 }
1337 device_initcall(smu_device_init);