smd.c 21.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
/* arch/arm/mach-msm/smd.c
 *
 * Copyright (C) 2007 Google, Inc.
 * Author: Brian Swetland <swetland@google.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/wait.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/debugfs.h>
#include <linux/delay.h>

#include <mach/msm_smd.h>
#include <mach/system.h>

#include "smd_private.h"
#include "proc_comm.h"

#if defined(CONFIG_ARCH_QSD8X50)
#define CONFIG_QDSP6 1
#endif

void (*msm_hw_reset_hook)(void);

#define MODULE_NAME "msm_smd"

enum {
	MSM_SMD_DEBUG = 1U << 0,
	MSM_SMSM_DEBUG = 1U << 0,
};

static int msm_smd_debug_mask;

struct shared_info {
	int ready;
	unsigned state;
};

static unsigned dummy_state[SMSM_STATE_COUNT];

static struct shared_info smd_info = {
	.state = (unsigned) &dummy_state,
};

module_param_named(debug_mask, msm_smd_debug_mask,
		   int, S_IRUGO | S_IWUSR | S_IWGRP);

static unsigned last_heap_free = 0xffffffff;

static inline void notify_other_smsm(void)
{
	msm_a2m_int(5);
#ifdef CONFIG_QDSP6
	msm_a2m_int(8);
#endif
}

static inline void notify_modem_smd(void)
{
	msm_a2m_int(0);
}

static inline void notify_dsp_smd(void)
{
	msm_a2m_int(8);
}

static void smd_diag(void)
{
	char *x;

	x = smem_find(ID_DIAG_ERR_MSG, SZ_DIAG_ERR_MSG);
	if (x != 0) {
		x[SZ_DIAG_ERR_MSG - 1] = 0;
		pr_debug("DIAG '%s'\n", x);
	}
}

/* call when SMSM_RESET flag is set in the A9's smsm_state */
static void handle_modem_crash(void)
{
	pr_err("ARM9 has CRASHED\n");
	smd_diag();

	/* hard reboot if possible */
	if (msm_hw_reset_hook)
		msm_hw_reset_hook();

	/* in this case the modem or watchdog should reboot us */
	for (;;)
		;
}

uint32_t raw_smsm_get_state(enum smsm_state_item item)
{
	return readl(smd_info.state + item * 4);
}

static int check_for_modem_crash(void)
{
	if (raw_smsm_get_state(SMSM_STATE_MODEM) & SMSM_RESET) {
		handle_modem_crash();
		return -1;
	}
	return 0;
}

/* the spinlock is used to synchronize between the
 * irq handler and code that mutates the channel
 * list or fiddles with channel state
 */
DEFINE_SPINLOCK(smd_lock);
DEFINE_SPINLOCK(smem_lock);

/* the mutex is used during open() and close()
 * operations to avoid races while creating or
 * destroying smd_channel structures
 */
static DEFINE_MUTEX(smd_creation_mutex);

static int smd_initialized;

LIST_HEAD(smd_ch_closed_list);
LIST_HEAD(smd_ch_list_modem);
LIST_HEAD(smd_ch_list_dsp);

static unsigned char smd_ch_allocated[64];
static struct work_struct probe_work;

/* how many bytes are available for reading */
static int smd_stream_read_avail(struct smd_channel *ch)
{
	return (ch->recv->head - ch->recv->tail) & ch->fifo_mask;
}

/* how many bytes we are free to write */
static int smd_stream_write_avail(struct smd_channel *ch)
{
	return ch->fifo_mask -
		((ch->send->head - ch->send->tail) & ch->fifo_mask);
}

static int smd_packet_read_avail(struct smd_channel *ch)
{
	if (ch->current_packet) {
		int n = smd_stream_read_avail(ch);
		if (n > ch->current_packet)
			n = ch->current_packet;
		return n;
	} else {
		return 0;
	}
}

static int smd_packet_write_avail(struct smd_channel *ch)
{
	int n = smd_stream_write_avail(ch);
	return n > SMD_HEADER_SIZE ? n - SMD_HEADER_SIZE : 0;
}

static int ch_is_open(struct smd_channel *ch)
{
	return (ch->recv->state == SMD_SS_OPENED) &&
		(ch->send->state == SMD_SS_OPENED);
}

/* provide a pointer and length to readable data in the fifo */
static unsigned ch_read_buffer(struct smd_channel *ch, void **ptr)
{
	unsigned head = ch->recv->head;
	unsigned tail = ch->recv->tail;
	*ptr = (void *) (ch->recv_data + tail);

	if (tail <= head)
		return head - tail;
	else
		return ch->fifo_size - tail;
}

/* advance the fifo read pointer after data from ch_read_buffer is consumed */
static void ch_read_done(struct smd_channel *ch, unsigned count)
{
	BUG_ON(count > smd_stream_read_avail(ch));
	ch->recv->tail = (ch->recv->tail + count) & ch->fifo_mask;
	ch->send->fTAIL = 1;
}

/* basic read interface to ch_read_{buffer,done} used
 * by smd_*_read() and update_packet_state()
 * will read-and-discard if the _data pointer is null
 */
static int ch_read(struct smd_channel *ch, void *_data, int len)
{
	void *ptr;
	unsigned n;
	unsigned char *data = _data;
	int orig_len = len;

	while (len > 0) {
		n = ch_read_buffer(ch, &ptr);
		if (n == 0)
			break;

		if (n > len)
			n = len;
		if (_data)
			memcpy(data, ptr, n);

		data += n;
		len -= n;
		ch_read_done(ch, n);
	}

	return orig_len - len;
}

static void update_stream_state(struct smd_channel *ch)
{
	/* streams have no special state requiring updating */
}

static void update_packet_state(struct smd_channel *ch)
{
	unsigned hdr[5];
	int r;

	/* can't do anything if we're in the middle of a packet */
	if (ch->current_packet != 0)
		return;

	/* don't bother unless we can get the full header */
	if (smd_stream_read_avail(ch) < SMD_HEADER_SIZE)
		return;

	r = ch_read(ch, hdr, SMD_HEADER_SIZE);
	BUG_ON(r != SMD_HEADER_SIZE);

	ch->current_packet = hdr[0];
}

/* provide a pointer and length to next free space in the fifo */
static unsigned ch_write_buffer(struct smd_channel *ch, void **ptr)
{
	unsigned head = ch->send->head;
	unsigned tail = ch->send->tail;
	*ptr = (void *) (ch->send_data + head);

	if (head < tail) {
		return tail - head - 1;
	} else {
		if (tail == 0)
			return ch->fifo_size - head - 1;
		else
			return ch->fifo_size - head;
	}
}

/* advace the fifo write pointer after freespace
 * from ch_write_buffer is filled
 */
static void ch_write_done(struct smd_channel *ch, unsigned count)
{
	BUG_ON(count > smd_stream_write_avail(ch));
	ch->send->head = (ch->send->head + count) & ch->fifo_mask;
	ch->send->fHEAD = 1;
}

static void ch_set_state(struct smd_channel *ch, unsigned n)
{
	if (n == SMD_SS_OPENED) {
		ch->send->fDSR = 1;
		ch->send->fCTS = 1;
		ch->send->fCD = 1;
	} else {
		ch->send->fDSR = 0;
		ch->send->fCTS = 0;
		ch->send->fCD = 0;
	}
	ch->send->state = n;
	ch->send->fSTATE = 1;
	ch->notify_other_cpu();
}

static void do_smd_probe(void)
{
	struct smem_shared *shared = (void *) MSM_SHARED_RAM_BASE;
	if (shared->heap_info.free_offset != last_heap_free) {
		last_heap_free = shared->heap_info.free_offset;
		schedule_work(&probe_work);
	}
}

static void smd_state_change(struct smd_channel *ch,
			     unsigned last, unsigned next)
{
	ch->last_state = next;

	pr_debug("ch %d %d -> %d\n", ch->n, last, next);

	switch (next) {
	case SMD_SS_OPENING:
		ch->recv->tail = 0;
	case SMD_SS_OPENED:
		if (ch->send->state != SMD_SS_OPENED)
			ch_set_state(ch, SMD_SS_OPENED);
		ch->notify(ch->priv, SMD_EVENT_OPEN);
		break;
	case SMD_SS_FLUSHING:
	case SMD_SS_RESET:
		/* we should force them to close? */
	default:
		ch->notify(ch->priv, SMD_EVENT_CLOSE);
	}
}

static void handle_smd_irq(struct list_head *list, void (*notify)(void))
{
	unsigned long flags;
	struct smd_channel *ch;
	int do_notify = 0;
	unsigned ch_flags;
	unsigned tmp;

	spin_lock_irqsave(&smd_lock, flags);
	list_for_each_entry(ch, list, ch_list) {
		ch_flags = 0;
		if (ch_is_open(ch)) {
			if (ch->recv->fHEAD) {
				ch->recv->fHEAD = 0;
				ch_flags |= 1;
				do_notify |= 1;
			}
			if (ch->recv->fTAIL) {
				ch->recv->fTAIL = 0;
				ch_flags |= 2;
				do_notify |= 1;
			}
			if (ch->recv->fSTATE) {
				ch->recv->fSTATE = 0;
				ch_flags |= 4;
				do_notify |= 1;
			}
		}
		tmp = ch->recv->state;
		if (tmp != ch->last_state)
			smd_state_change(ch, ch->last_state, tmp);
		if (ch_flags) {
			ch->update_state(ch);
			ch->notify(ch->priv, SMD_EVENT_DATA);
		}
	}
	if (do_notify)
		notify();
	spin_unlock_irqrestore(&smd_lock, flags);
	do_smd_probe();
}

static irqreturn_t smd_modem_irq_handler(int irq, void *data)
{
	handle_smd_irq(&smd_ch_list_modem, notify_modem_smd);
	return IRQ_HANDLED;
}

#if defined(CONFIG_QDSP6)
static irqreturn_t smd_dsp_irq_handler(int irq, void *data)
{
	handle_smd_irq(&smd_ch_list_dsp, notify_dsp_smd);
	return IRQ_HANDLED;
}
#endif

static void smd_fake_irq_handler(unsigned long arg)
{
	handle_smd_irq(&smd_ch_list_modem, notify_modem_smd);
	handle_smd_irq(&smd_ch_list_dsp, notify_dsp_smd);
}

static DECLARE_TASKLET(smd_fake_irq_tasklet, smd_fake_irq_handler, 0);

static inline int smd_need_int(struct smd_channel *ch)
{
	if (ch_is_open(ch)) {
		if (ch->recv->fHEAD || ch->recv->fTAIL || ch->recv->fSTATE)
			return 1;
		if (ch->recv->state != ch->last_state)
			return 1;
	}
	return 0;
}

void smd_sleep_exit(void)
{
	unsigned long flags;
	struct smd_channel *ch;
	int need_int = 0;

	spin_lock_irqsave(&smd_lock, flags);
	list_for_each_entry(ch, &smd_ch_list_modem, ch_list) {
		if (smd_need_int(ch)) {
			need_int = 1;
			break;
		}
	}
	list_for_each_entry(ch, &smd_ch_list_dsp, ch_list) {
		if (smd_need_int(ch)) {
			need_int = 1;
			break;
		}
	}
	spin_unlock_irqrestore(&smd_lock, flags);
	do_smd_probe();

	if (need_int) {
		if (msm_smd_debug_mask & MSM_SMD_DEBUG)
			pr_info("smd_sleep_exit need interrupt\n");
		tasklet_schedule(&smd_fake_irq_tasklet);
	}
}


void smd_kick(smd_channel_t *ch)
{
	unsigned long flags;
	unsigned tmp;

	spin_lock_irqsave(&smd_lock, flags);
	ch->update_state(ch);
	tmp = ch->recv->state;
	if (tmp != ch->last_state) {
		ch->last_state = tmp;
		if (tmp == SMD_SS_OPENED)
			ch->notify(ch->priv, SMD_EVENT_OPEN);
		else
			ch->notify(ch->priv, SMD_EVENT_CLOSE);
	}
	ch->notify(ch->priv, SMD_EVENT_DATA);
	ch->notify_other_cpu();
	spin_unlock_irqrestore(&smd_lock, flags);
}

static int smd_is_packet(int chn, unsigned type)
{
	type &= SMD_KIND_MASK;
	if (type == SMD_KIND_PACKET)
		return 1;
	if (type == SMD_KIND_STREAM)
		return 0;

	/* older AMSS reports SMD_KIND_UNKNOWN always */
	if ((chn > 4) || (chn == 1))
		return 1;
	else
		return 0;
}

static int smd_stream_write(smd_channel_t *ch, const void *_data, int len)
{
	void *ptr;
	const unsigned char *buf = _data;
	unsigned xfer;
	int orig_len = len;

	if (len < 0)
		return -EINVAL;

	while ((xfer = ch_write_buffer(ch, &ptr)) != 0) {
		if (!ch_is_open(ch))
			break;
		if (xfer > len)
			xfer = len;
		memcpy(ptr, buf, xfer);
		ch_write_done(ch, xfer);
		len -= xfer;
		buf += xfer;
		if (len == 0)
			break;
	}

	ch->notify_other_cpu();

	return orig_len - len;
}

static int smd_packet_write(smd_channel_t *ch, const void *_data, int len)
{
	unsigned hdr[5];

	if (len < 0)
		return -EINVAL;

	if (smd_stream_write_avail(ch) < (len + SMD_HEADER_SIZE))
		return -ENOMEM;

	hdr[0] = len;
	hdr[1] = hdr[2] = hdr[3] = hdr[4] = 0;

	smd_stream_write(ch, hdr, sizeof(hdr));
	smd_stream_write(ch, _data, len);

	return len;
}

static int smd_stream_read(smd_channel_t *ch, void *data, int len)
{
	int r;

	if (len < 0)
		return -EINVAL;

	r = ch_read(ch, data, len);
	if (r > 0)
		ch->notify_other_cpu();

	return r;
}

static int smd_packet_read(smd_channel_t *ch, void *data, int len)
{
	unsigned long flags;
	int r;

	if (len < 0)
		return -EINVAL;

	if (len > ch->current_packet)
		len = ch->current_packet;

	r = ch_read(ch, data, len);
	if (r > 0)
		ch->notify_other_cpu();

	spin_lock_irqsave(&smd_lock, flags);
	ch->current_packet -= r;
	update_packet_state(ch);
	spin_unlock_irqrestore(&smd_lock, flags);

	return r;
}

static int smd_alloc_channel(const char *name, uint32_t cid, uint32_t type)
{
	struct smd_channel *ch;

	ch = kzalloc(sizeof(struct smd_channel), GFP_KERNEL);
	if (ch == 0) {
		pr_err("smd_alloc_channel() out of memory\n");
		return -1;
	}
	ch->n = cid;

	if (_smd_alloc_channel(ch)) {
		kfree(ch);
		return -1;
	}

	ch->fifo_mask = ch->fifo_size - 1;
	ch->type = type;

	if ((type & SMD_TYPE_MASK) == SMD_TYPE_APPS_MODEM)
		ch->notify_other_cpu = notify_modem_smd;
	else
		ch->notify_other_cpu = notify_dsp_smd;

	if (smd_is_packet(cid, type)) {
		ch->read = smd_packet_read;
		ch->write = smd_packet_write;
		ch->read_avail = smd_packet_read_avail;
		ch->write_avail = smd_packet_write_avail;
		ch->update_state = update_packet_state;
	} else {
		ch->read = smd_stream_read;
		ch->write = smd_stream_write;
		ch->read_avail = smd_stream_read_avail;
		ch->write_avail = smd_stream_write_avail;
		ch->update_state = update_stream_state;
	}

	if ((type & 0xff) == 0)
		memcpy(ch->name, "SMD_", 4);
	else
		memcpy(ch->name, "DSP_", 4);
	memcpy(ch->name + 4, name, 20);
	ch->name[23] = 0;
	ch->pdev.name = ch->name;
	ch->pdev.id = -1;

	pr_debug("smd_alloc_channel() cid=%02d size=%05d '%s'\n",
		ch->n, ch->fifo_size, ch->name);

	mutex_lock(&smd_creation_mutex);
	list_add(&ch->ch_list, &smd_ch_closed_list);
	mutex_unlock(&smd_creation_mutex);

	platform_device_register(&ch->pdev);
	return 0;
}

static void smd_channel_probe_worker(struct work_struct *work)
{
	struct smd_alloc_elm *shared;
	unsigned ctype;
	unsigned type;
	unsigned n;

	shared = smem_find(ID_CH_ALLOC_TBL, sizeof(*shared) * 64);
	if (!shared) {
		pr_err("cannot find allocation table\n");
		return;
	}
	for (n = 0; n < 64; n++) {
		if (smd_ch_allocated[n])
			continue;
		if (!shared[n].ref_count)
			continue;
		if (!shared[n].name[0])
			continue;
		ctype = shared[n].ctype;
		type = ctype & SMD_TYPE_MASK;

		/* DAL channels are stream but neither the modem,
		 * nor the DSP correctly indicate this.  Fixup manually.
		 */
		if (!memcmp(shared[n].name, "DAL", 3))
			ctype = (ctype & (~SMD_KIND_MASK)) | SMD_KIND_STREAM;

		type = shared[n].ctype & SMD_TYPE_MASK;
		if ((type == SMD_TYPE_APPS_MODEM) ||
		    (type == SMD_TYPE_APPS_DSP))
			if (!smd_alloc_channel(shared[n].name, shared[n].cid, ctype))
				smd_ch_allocated[n] = 1;
	}
}

static void do_nothing_notify(void *priv, unsigned flags)
{
}

struct smd_channel *smd_get_channel(const char *name)
{
	struct smd_channel *ch;

	mutex_lock(&smd_creation_mutex);
	list_for_each_entry(ch, &smd_ch_closed_list, ch_list) {
		if (!strcmp(name, ch->name)) {
			list_del(&ch->ch_list);
			mutex_unlock(&smd_creation_mutex);
			return ch;
		}
	}
	mutex_unlock(&smd_creation_mutex);

	return NULL;
}

int smd_open(const char *name, smd_channel_t **_ch,
	     void *priv, void (*notify)(void *, unsigned))
{
	struct smd_channel *ch;
	unsigned long flags;

	if (smd_initialized == 0) {
		pr_info("smd_open() before smd_init()\n");
		return -ENODEV;
	}

	ch = smd_get_channel(name);
	if (!ch)
		return -ENODEV;

	if (notify == 0)
		notify = do_nothing_notify;

	ch->notify = notify;
	ch->current_packet = 0;
	ch->last_state = SMD_SS_CLOSED;
	ch->priv = priv;

	*_ch = ch;

	spin_lock_irqsave(&smd_lock, flags);

	if ((ch->type & SMD_TYPE_MASK) == SMD_TYPE_APPS_MODEM)
		list_add(&ch->ch_list, &smd_ch_list_modem);
	else
		list_add(&ch->ch_list, &smd_ch_list_dsp);

	/* If the remote side is CLOSING, we need to get it to
	 * move to OPENING (which we'll do by moving from CLOSED to
	 * OPENING) and then get it to move from OPENING to
	 * OPENED (by doing the same state change ourselves).
	 *
	 * Otherwise, it should be OPENING and we can move directly
	 * to OPENED so that it will follow.
	 */
	if (ch->recv->state == SMD_SS_CLOSING) {
		ch->send->head = 0;
		ch_set_state(ch, SMD_SS_OPENING);
	} else {
		ch_set_state(ch, SMD_SS_OPENED);
	}
	spin_unlock_irqrestore(&smd_lock, flags);
	smd_kick(ch);

	return 0;
}

int smd_close(smd_channel_t *ch)
{
	unsigned long flags;

	if (ch == 0)
		return -1;

	spin_lock_irqsave(&smd_lock, flags);
	ch->notify = do_nothing_notify;
	list_del(&ch->ch_list);
	ch_set_state(ch, SMD_SS_CLOSED);
	spin_unlock_irqrestore(&smd_lock, flags);

	mutex_lock(&smd_creation_mutex);
	list_add(&ch->ch_list, &smd_ch_closed_list);
	mutex_unlock(&smd_creation_mutex);

	return 0;
}

int smd_read(smd_channel_t *ch, void *data, int len)
{
	return ch->read(ch, data, len);
}

int smd_write(smd_channel_t *ch, const void *data, int len)
{
	return ch->write(ch, data, len);
}

int smd_write_atomic(smd_channel_t *ch, const void *data, int len)
{
	unsigned long flags;
	int res;
	spin_lock_irqsave(&smd_lock, flags);
	res = ch->write(ch, data, len);
	spin_unlock_irqrestore(&smd_lock, flags);
	return res;
}

int smd_read_avail(smd_channel_t *ch)
{
	return ch->read_avail(ch);
}

int smd_write_avail(smd_channel_t *ch)
{
	return ch->write_avail(ch);
}

int smd_wait_until_readable(smd_channel_t *ch, int bytes)
{
	return -1;
}

int smd_wait_until_writable(smd_channel_t *ch, int bytes)
{
	return -1;
}

int smd_cur_packet_size(smd_channel_t *ch)
{
	return ch->current_packet;
}


/* ------------------------------------------------------------------------- */

void *smem_alloc(unsigned id, unsigned size)
{
	return smem_find(id, size);
}

void *smem_item(unsigned id, unsigned *size)
{
	struct smem_shared *shared = (void *) MSM_SHARED_RAM_BASE;
	struct smem_heap_entry *toc = shared->heap_toc;

	if (id >= SMEM_NUM_ITEMS)
		return 0;

	if (toc[id].allocated) {
		*size = toc[id].size;
		return (void *) (MSM_SHARED_RAM_BASE + toc[id].offset);
	} else {
		*size = 0;
	}

	return 0;
}

void *smem_find(unsigned id, unsigned size_in)
{
	unsigned size;
	void *ptr;

	ptr = smem_item(id, &size);
	if (!ptr)
		return 0;

	size_in = ALIGN(size_in, 8);
	if (size_in != size) {
		pr_err("smem_find(%d, %d): wrong size %d\n",
		       id, size_in, size);
		return 0;
	}

	return ptr;
}

static irqreturn_t smsm_irq_handler(int irq, void *data)
{
	unsigned long flags;
	unsigned apps, modm;

	spin_lock_irqsave(&smem_lock, flags);

	apps = raw_smsm_get_state(SMSM_STATE_APPS);
	modm = raw_smsm_get_state(SMSM_STATE_MODEM);

	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
		pr_info("<SM %08x %08x>\n", apps, modm);
	if (modm & SMSM_RESET)
		handle_modem_crash();

	do_smd_probe();

	spin_unlock_irqrestore(&smem_lock, flags);
	return IRQ_HANDLED;
}

int smsm_change_state(enum smsm_state_item item,
		      uint32_t clear_mask, uint32_t set_mask)
{
	unsigned long addr = smd_info.state + item * 4;
	unsigned long flags;
	unsigned state;

	if (!smd_info.ready)
		return -EIO;

	spin_lock_irqsave(&smem_lock, flags);

	if (raw_smsm_get_state(SMSM_STATE_MODEM) & SMSM_RESET)
		handle_modem_crash();

	state = (readl(addr) & ~clear_mask) | set_mask;
	writel(state, addr);

	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
		pr_info("smsm_change_state %d %x\n", item, state);
	notify_other_smsm();

	spin_unlock_irqrestore(&smem_lock, flags);

	return 0;
}

uint32_t smsm_get_state(enum smsm_state_item item)
{
	unsigned long flags;
	uint32_t rv;

	spin_lock_irqsave(&smem_lock, flags);

	rv = readl(smd_info.state + item * 4);

	if (item == SMSM_STATE_MODEM && (rv & SMSM_RESET))
		handle_modem_crash();

	spin_unlock_irqrestore(&smem_lock, flags);

	return rv;
}

#ifdef CONFIG_ARCH_MSM_SCORPION

int smsm_set_sleep_duration(uint32_t delay)
{
	struct msm_dem_slave_data *ptr;

	ptr = smem_find(SMEM_APPS_DEM_SLAVE_DATA, sizeof(*ptr));
	if (ptr == NULL) {
		pr_err("smsm_set_sleep_duration <SM NO APPS_DEM_SLAVE_DATA>\n");
		return -EIO;
	}
	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
		pr_info("smsm_set_sleep_duration %d -> %d\n",
		       ptr->sleep_time, delay);
	ptr->sleep_time = delay;
	return 0;
}

#else

int smsm_set_sleep_duration(uint32_t delay)
{
	uint32_t *ptr;

	ptr = smem_find(SMEM_SMSM_SLEEP_DELAY, sizeof(*ptr));
	if (ptr == NULL) {
		pr_err("smsm_set_sleep_duration <SM NO SLEEP_DELAY>\n");
		return -EIO;
	}
	if (msm_smd_debug_mask & MSM_SMSM_DEBUG)
		pr_info("smsm_set_sleep_duration %d -> %d\n",
		       *ptr, delay);
	*ptr = delay;
	return 0;
}

#endif

int smd_core_init(void)
{
	int r;

	/* wait for essential items to be initialized */
	for (;;) {
		unsigned size;
		void *state;
		state = smem_item(SMEM_SMSM_SHARED_STATE, &size);
		if (size == SMSM_V1_SIZE || size == SMSM_V2_SIZE) {
			smd_info.state = (unsigned)state;
			break;
		}
	}

	smd_info.ready = 1;

	r = request_irq(INT_A9_M2A_0, smd_modem_irq_handler,
			IRQF_TRIGGER_RISING, "smd_dev", 0);
	if (r < 0)
		return r;
	r = enable_irq_wake(INT_A9_M2A_0);
	if (r < 0)
		pr_err("smd_core_init: enable_irq_wake failed for A9_M2A_0\n");

	r = request_irq(INT_A9_M2A_5, smsm_irq_handler,
			IRQF_TRIGGER_RISING, "smsm_dev", 0);
	if (r < 0) {
		free_irq(INT_A9_M2A_0, 0);
		return r;
	}
	r = enable_irq_wake(INT_A9_M2A_5);
	if (r < 0)
		pr_err("smd_core_init: enable_irq_wake failed for A9_M2A_5\n");

#if defined(CONFIG_QDSP6)
	r = request_irq(INT_ADSP_A11, smd_dsp_irq_handler,
			IRQF_TRIGGER_RISING, "smd_dsp", 0);
	if (r < 0) {
		free_irq(INT_A9_M2A_0, 0);
		free_irq(INT_A9_M2A_5, 0);
		return r;
	}
#endif

	/* check for any SMD channels that may already exist */
	do_smd_probe();

	/* indicate that we're up and running */
	smsm_change_state(SMSM_STATE_APPS,
			  ~0, SMSM_INIT | SMSM_SMDINIT | SMSM_RPCINIT | SMSM_RUN);
#ifdef CONFIG_ARCH_MSM_SCORPION
	smsm_change_state(SMSM_STATE_APPS_DEM, ~0, 0);
#endif

	return 0;
}

static int __devinit msm_smd_probe(struct platform_device *pdev)
{
	/*
	 * If we haven't waited for the ARM9 to boot up till now,
	 * then we need to wait here. Otherwise this should just
	 * return immediately.
	 */
	proc_comm_boot_wait();

	INIT_WORK(&probe_work, smd_channel_probe_worker);

	if (smd_core_init()) {
		pr_err("smd_core_init() failed\n");
		return -1;
	}

	do_smd_probe();

	msm_check_for_modem_crash = check_for_modem_crash;

	msm_init_last_radio_log(THIS_MODULE);

	smd_initialized = 1;

	return 0;
}

static struct platform_driver msm_smd_driver = {
	.probe = msm_smd_probe,
	.driver = {
		.name = MODULE_NAME,
		.owner = THIS_MODULE,
	},
};

static int __init msm_smd_init(void)
{
	return platform_driver_register(&msm_smd_driver);
}

module_init(msm_smd_init);

MODULE_DESCRIPTION("MSM Shared Memory Core");
MODULE_AUTHOR("Brian Swetland <swetland@google.com>");
MODULE_LICENSE("GPL");