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v3.1
   1/*
   2 * PowerMac G5 SMU driver
   3 *
   4 * Copyright 2004 J. Mayer <l_indien@magic.fr>
   5 * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   6 *
   7 * Released under the term of the GNU GPL v2.
   8 */
   9
  10/*
  11 * TODO:
  12 *  - maybe add timeout to commands ?
  13 *  - blocking version of time functions
  14 *  - polling version of i2c commands (including timer that works with
  15 *    interrupts off)
  16 *  - maybe avoid some data copies with i2c by directly using the smu cmd
  17 *    buffer and a lower level internal interface
  18 *  - understand SMU -> CPU events and implement reception of them via
  19 *    the userland interface
  20 */
  21
  22#include <linux/types.h>
  23#include <linux/kernel.h>
  24#include <linux/device.h>
  25#include <linux/dmapool.h>
  26#include <linux/bootmem.h>
  27#include <linux/vmalloc.h>
  28#include <linux/highmem.h>
  29#include <linux/jiffies.h>
  30#include <linux/interrupt.h>
  31#include <linux/rtc.h>
  32#include <linux/completion.h>
  33#include <linux/miscdevice.h>
  34#include <linux/delay.h>
  35#include <linux/sysdev.h>
  36#include <linux/poll.h>
  37#include <linux/mutex.h>
  38#include <linux/of_device.h>
  39#include <linux/of_platform.h>
  40#include <linux/slab.h>
  41
  42#include <asm/byteorder.h>
  43#include <asm/io.h>
  44#include <asm/prom.h>
  45#include <asm/machdep.h>
  46#include <asm/pmac_feature.h>
  47#include <asm/smu.h>
  48#include <asm/sections.h>
  49#include <asm/abs_addr.h>
  50#include <asm/uaccess.h>
  51
  52#define VERSION "0.7"
  53#define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  54
  55#undef DEBUG_SMU
  56
  57#ifdef DEBUG_SMU
  58#define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  59#else
  60#define DPRINTK(fmt, args...) do { } while (0)
  61#endif
  62
  63/*
  64 * This is the command buffer passed to the SMU hardware
  65 */
  66#define SMU_MAX_DATA	254
  67
  68struct smu_cmd_buf {
  69	u8 cmd;
  70	u8 length;
  71	u8 data[SMU_MAX_DATA];
  72};
  73
  74struct smu_device {
  75	spinlock_t		lock;
  76	struct device_node	*of_node;
  77	struct platform_device	*of_dev;
  78	int			doorbell;	/* doorbell gpio */
  79	u32 __iomem		*db_buf;	/* doorbell buffer */
  80	struct device_node	*db_node;
  81	unsigned int		db_irq;
  82	int			msg;
  83	struct device_node	*msg_node;
  84	unsigned int		msg_irq;
  85	struct smu_cmd_buf	*cmd_buf;	/* command buffer virtual */
  86	u32			cmd_buf_abs;	/* command buffer absolute */
  87	struct list_head	cmd_list;
  88	struct smu_cmd		*cmd_cur;	/* pending command */
  89	int			broken_nap;
  90	struct list_head	cmd_i2c_list;
  91	struct smu_i2c_cmd	*cmd_i2c_cur;	/* pending i2c command */
  92	struct timer_list	i2c_timer;
  93};
  94
  95/*
  96 * I don't think there will ever be more than one SMU, so
  97 * for now, just hard code that
  98 */
  99static DEFINE_MUTEX(smu_mutex);
 100static struct smu_device	*smu;
 101static DEFINE_MUTEX(smu_part_access);
 102static int smu_irq_inited;
 103
 104static void smu_i2c_retry(unsigned long data);
 105
 106/*
 107 * SMU driver low level stuff
 108 */
 109
 110static void smu_start_cmd(void)
 111{
 112	unsigned long faddr, fend;
 113	struct smu_cmd *cmd;
 114
 115	if (list_empty(&smu->cmd_list))
 116		return;
 117
 118	/* Fetch first command in queue */
 119	cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
 120	smu->cmd_cur = cmd;
 121	list_del(&cmd->link);
 122
 123	DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
 124		cmd->data_len);
 125	DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 126		((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 127		((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 128		((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 129		((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 130
 131	/* Fill the SMU command buffer */
 132	smu->cmd_buf->cmd = cmd->cmd;
 133	smu->cmd_buf->length = cmd->data_len;
 134	memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 135
 136	/* Flush command and data to RAM */
 137	faddr = (unsigned long)smu->cmd_buf;
 138	fend = faddr + smu->cmd_buf->length + 2;
 139	flush_inval_dcache_range(faddr, fend);
 140
 141
 142	/* We also disable NAP mode for the duration of the command
 143	 * on U3 based machines.
 144	 * This is slightly racy as it can be written back to 1 by a sysctl
 145	 * but that never happens in practice. There seem to be an issue with
 146	 * U3 based machines such as the iMac G5 where napping for the
 147	 * whole duration of the command prevents the SMU from fetching it
 148	 * from memory. This might be related to the strange i2c based
 149	 * mechanism the SMU uses to access memory.
 150	 */
 151	if (smu->broken_nap)
 152		powersave_nap = 0;
 153
 154	/* This isn't exactly a DMA mapping here, I suspect
 155	 * the SMU is actually communicating with us via i2c to the
 156	 * northbridge or the CPU to access RAM.
 157	 */
 158	writel(smu->cmd_buf_abs, smu->db_buf);
 159
 160	/* Ring the SMU doorbell */
 161	pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 162}
 163
 164
 165static irqreturn_t smu_db_intr(int irq, void *arg)
 166{
 167	unsigned long flags;
 168	struct smu_cmd *cmd;
 169	void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 170	void *misc = NULL;
 171	u8 gpio;
 172	int rc = 0;
 173
 174	/* SMU completed the command, well, we hope, let's make sure
 175	 * of it
 176	 */
 177	spin_lock_irqsave(&smu->lock, flags);
 178
 179	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 180	if ((gpio & 7) != 7) {
 181		spin_unlock_irqrestore(&smu->lock, flags);
 182		return IRQ_HANDLED;
 183	}
 184
 185	cmd = smu->cmd_cur;
 186	smu->cmd_cur = NULL;
 187	if (cmd == NULL)
 188		goto bail;
 189
 190	if (rc == 0) {
 191		unsigned long faddr;
 192		int reply_len;
 193		u8 ack;
 194
 195		/* CPU might have brought back the cache line, so we need
 196		 * to flush again before peeking at the SMU response. We
 197		 * flush the entire buffer for now as we haven't read the
 198		 * reply length (it's only 2 cache lines anyway)
 199		 */
 200		faddr = (unsigned long)smu->cmd_buf;
 201		flush_inval_dcache_range(faddr, faddr + 256);
 202
 203		/* Now check ack */
 204		ack = (~cmd->cmd) & 0xff;
 205		if (ack != smu->cmd_buf->cmd) {
 206			DPRINTK("SMU: incorrect ack, want %x got %x\n",
 207				ack, smu->cmd_buf->cmd);
 208			rc = -EIO;
 209		}
 210		reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 211		DPRINTK("SMU: reply len: %d\n", reply_len);
 212		if (reply_len > cmd->reply_len) {
 213			printk(KERN_WARNING "SMU: reply buffer too small,"
 214			       "got %d bytes for a %d bytes buffer\n",
 215			       reply_len, cmd->reply_len);
 216			reply_len = cmd->reply_len;
 217		}
 218		cmd->reply_len = reply_len;
 219		if (cmd->reply_buf && reply_len)
 220			memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 221	}
 222
 223	/* Now complete the command. Write status last in order as we lost
 224	 * ownership of the command structure as soon as it's no longer -1
 225	 */
 226	done = cmd->done;
 227	misc = cmd->misc;
 228	mb();
 229	cmd->status = rc;
 230
 231	/* Re-enable NAP mode */
 232	if (smu->broken_nap)
 233		powersave_nap = 1;
 234 bail:
 235	/* Start next command if any */
 236	smu_start_cmd();
 237	spin_unlock_irqrestore(&smu->lock, flags);
 238
 239	/* Call command completion handler if any */
 240	if (done)
 241		done(cmd, misc);
 242
 243	/* It's an edge interrupt, nothing to do */
 244	return IRQ_HANDLED;
 245}
 246
 247
 248static irqreturn_t smu_msg_intr(int irq, void *arg)
 249{
 250	/* I don't quite know what to do with this one, we seem to never
 251	 * receive it, so I suspect we have to arm it someway in the SMU
 252	 * to start getting events that way.
 253	 */
 254
 255	printk(KERN_INFO "SMU: message interrupt !\n");
 256
 257	/* It's an edge interrupt, nothing to do */
 258	return IRQ_HANDLED;
 259}
 260
 261
 262/*
 263 * Queued command management.
 264 *
 265 */
 266
 267int smu_queue_cmd(struct smu_cmd *cmd)
 268{
 269	unsigned long flags;
 270
 271	if (smu == NULL)
 272		return -ENODEV;
 273	if (cmd->data_len > SMU_MAX_DATA ||
 274	    cmd->reply_len > SMU_MAX_DATA)
 275		return -EINVAL;
 276
 277	cmd->status = 1;
 278	spin_lock_irqsave(&smu->lock, flags);
 279	list_add_tail(&cmd->link, &smu->cmd_list);
 280	if (smu->cmd_cur == NULL)
 281		smu_start_cmd();
 282	spin_unlock_irqrestore(&smu->lock, flags);
 283
 284	/* Workaround for early calls when irq isn't available */
 285	if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 286		smu_spinwait_cmd(cmd);
 287
 288	return 0;
 289}
 290EXPORT_SYMBOL(smu_queue_cmd);
 291
 292
 293int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 294		     unsigned int data_len,
 295		     void (*done)(struct smu_cmd *cmd, void *misc),
 296		     void *misc, ...)
 297{
 298	struct smu_cmd *cmd = &scmd->cmd;
 299	va_list list;
 300	int i;
 301
 302	if (data_len > sizeof(scmd->buffer))
 303		return -EINVAL;
 304
 305	memset(scmd, 0, sizeof(*scmd));
 306	cmd->cmd = command;
 307	cmd->data_len = data_len;
 308	cmd->data_buf = scmd->buffer;
 309	cmd->reply_len = sizeof(scmd->buffer);
 310	cmd->reply_buf = scmd->buffer;
 311	cmd->done = done;
 312	cmd->misc = misc;
 313
 314	va_start(list, misc);
 315	for (i = 0; i < data_len; ++i)
 316		scmd->buffer[i] = (u8)va_arg(list, int);
 317	va_end(list);
 318
 319	return smu_queue_cmd(cmd);
 320}
 321EXPORT_SYMBOL(smu_queue_simple);
 322
 323
 324void smu_poll(void)
 325{
 326	u8 gpio;
 327
 328	if (smu == NULL)
 329		return;
 330
 331	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 332	if ((gpio & 7) == 7)
 333		smu_db_intr(smu->db_irq, smu);
 334}
 335EXPORT_SYMBOL(smu_poll);
 336
 337
 338void smu_done_complete(struct smu_cmd *cmd, void *misc)
 339{
 340	struct completion *comp = misc;
 341
 342	complete(comp);
 343}
 344EXPORT_SYMBOL(smu_done_complete);
 345
 346
 347void smu_spinwait_cmd(struct smu_cmd *cmd)
 348{
 349	while(cmd->status == 1)
 350		smu_poll();
 351}
 352EXPORT_SYMBOL(smu_spinwait_cmd);
 353
 354
 355/* RTC low level commands */
 356static inline int bcd2hex (int n)
 357{
 358	return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 359}
 360
 361
 362static inline int hex2bcd (int n)
 363{
 364	return ((n / 10) << 4) + (n % 10);
 365}
 366
 367
 368static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 369					struct rtc_time *time)
 370{
 371	cmd_buf->cmd = 0x8e;
 372	cmd_buf->length = 8;
 373	cmd_buf->data[0] = 0x80;
 374	cmd_buf->data[1] = hex2bcd(time->tm_sec);
 375	cmd_buf->data[2] = hex2bcd(time->tm_min);
 376	cmd_buf->data[3] = hex2bcd(time->tm_hour);
 377	cmd_buf->data[4] = time->tm_wday;
 378	cmd_buf->data[5] = hex2bcd(time->tm_mday);
 379	cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 380	cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 381}
 382
 383
 384int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 385{
 386	struct smu_simple_cmd cmd;
 387	int rc;
 388
 389	if (smu == NULL)
 390		return -ENODEV;
 391
 392	memset(time, 0, sizeof(struct rtc_time));
 393	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 394			      SMU_CMD_RTC_GET_DATETIME);
 395	if (rc)
 396		return rc;
 397	smu_spinwait_simple(&cmd);
 398
 399	time->tm_sec = bcd2hex(cmd.buffer[0]);
 400	time->tm_min = bcd2hex(cmd.buffer[1]);
 401	time->tm_hour = bcd2hex(cmd.buffer[2]);
 402	time->tm_wday = bcd2hex(cmd.buffer[3]);
 403	time->tm_mday = bcd2hex(cmd.buffer[4]);
 404	time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 405	time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 406
 407	return 0;
 408}
 409
 410
 411int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 412{
 413	struct smu_simple_cmd cmd;
 414	int rc;
 415
 416	if (smu == NULL)
 417		return -ENODEV;
 418
 419	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 420			      SMU_CMD_RTC_SET_DATETIME,
 421			      hex2bcd(time->tm_sec),
 422			      hex2bcd(time->tm_min),
 423			      hex2bcd(time->tm_hour),
 424			      time->tm_wday,
 425			      hex2bcd(time->tm_mday),
 426			      hex2bcd(time->tm_mon) + 1,
 427			      hex2bcd(time->tm_year - 100));
 428	if (rc)
 429		return rc;
 430	smu_spinwait_simple(&cmd);
 431
 432	return 0;
 433}
 434
 435
 436void smu_shutdown(void)
 437{
 438	struct smu_simple_cmd cmd;
 439
 440	if (smu == NULL)
 441		return;
 442
 443	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 444			     'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 445		return;
 446	smu_spinwait_simple(&cmd);
 447	for (;;)
 448		;
 449}
 450
 451
 452void smu_restart(void)
 453{
 454	struct smu_simple_cmd cmd;
 455
 456	if (smu == NULL)
 457		return;
 458
 459	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 460			     'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 461		return;
 462	smu_spinwait_simple(&cmd);
 463	for (;;)
 464		;
 465}
 466
 467
 468int smu_present(void)
 469{
 470	return smu != NULL;
 471}
 472EXPORT_SYMBOL(smu_present);
 473
 474
 475int __init smu_init (void)
 476{
 477	struct device_node *np;
 478	const u32 *data;
 479	int ret = 0;
 480
 481        np = of_find_node_by_type(NULL, "smu");
 482        if (np == NULL)
 483		return -ENODEV;
 484
 485	printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 486
 487	if (smu_cmdbuf_abs == 0) {
 488		printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 489		ret = -EINVAL;
 490		goto fail_np;
 491	}
 492
 493	smu = alloc_bootmem(sizeof(struct smu_device));
 494
 495	spin_lock_init(&smu->lock);
 496	INIT_LIST_HEAD(&smu->cmd_list);
 497	INIT_LIST_HEAD(&smu->cmd_i2c_list);
 498	smu->of_node = np;
 499	smu->db_irq = NO_IRQ;
 500	smu->msg_irq = NO_IRQ;
 501
 502	/* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 503	 * 32 bits value safely
 504	 */
 505	smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 506	smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 507
 508	smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 509	if (smu->db_node == NULL) {
 510		printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 511		ret = -ENXIO;
 512		goto fail_bootmem;
 513	}
 514	data = of_get_property(smu->db_node, "reg", NULL);
 515	if (data == NULL) {
 516		printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 517		ret = -ENXIO;
 518		goto fail_db_node;
 519	}
 520
 521	/* Current setup has one doorbell GPIO that does both doorbell
 522	 * and ack. GPIOs are at 0x50, best would be to find that out
 523	 * in the device-tree though.
 524	 */
 525	smu->doorbell = *data;
 526	if (smu->doorbell < 0x50)
 527		smu->doorbell += 0x50;
 528
 529	/* Now look for the smu-interrupt GPIO */
 530	do {
 531		smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 532		if (smu->msg_node == NULL)
 533			break;
 534		data = of_get_property(smu->msg_node, "reg", NULL);
 535		if (data == NULL) {
 536			of_node_put(smu->msg_node);
 537			smu->msg_node = NULL;
 538			break;
 539		}
 540		smu->msg = *data;
 541		if (smu->msg < 0x50)
 542			smu->msg += 0x50;
 543	} while(0);
 544
 545	/* Doorbell buffer is currently hard-coded, I didn't find a proper
 546	 * device-tree entry giving the address. Best would probably to use
 547	 * an offset for K2 base though, but let's do it that way for now.
 548	 */
 549	smu->db_buf = ioremap(0x8000860c, 0x1000);
 550	if (smu->db_buf == NULL) {
 551		printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 552		ret = -ENXIO;
 553		goto fail_msg_node;
 554	}
 555
 556	/* U3 has an issue with NAP mode when issuing SMU commands */
 557	smu->broken_nap = pmac_get_uninorth_variant() < 4;
 558	if (smu->broken_nap)
 559		printk(KERN_INFO "SMU: using NAP mode workaround\n");
 560
 561	sys_ctrler = SYS_CTRLER_SMU;
 562	return 0;
 563
 564fail_msg_node:
 565	if (smu->msg_node)
 566		of_node_put(smu->msg_node);
 567fail_db_node:
 568	of_node_put(smu->db_node);
 569fail_bootmem:
 570	free_bootmem((unsigned long)smu, sizeof(struct smu_device));
 571	smu = NULL;
 572fail_np:
 573	of_node_put(np);
 574	return ret;
 575}
 576
 577
 578static int smu_late_init(void)
 579{
 580	if (!smu)
 581		return 0;
 582
 583	init_timer(&smu->i2c_timer);
 584	smu->i2c_timer.function = smu_i2c_retry;
 585	smu->i2c_timer.data = (unsigned long)smu;
 586
 587	if (smu->db_node) {
 588		smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 589		if (smu->db_irq == NO_IRQ)
 590			printk(KERN_ERR "smu: failed to map irq for node %s\n",
 591			       smu->db_node->full_name);
 592	}
 593	if (smu->msg_node) {
 594		smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 595		if (smu->msg_irq == NO_IRQ)
 596			printk(KERN_ERR "smu: failed to map irq for node %s\n",
 597			       smu->msg_node->full_name);
 598	}
 599
 600	/*
 601	 * Try to request the interrupts
 602	 */
 603
 604	if (smu->db_irq != NO_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 = NO_IRQ;
 611		}
 612	}
 613
 614	if (smu->msg_irq != NO_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 = NO_IRQ;
 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 */
 630core_initcall(smu_late_init);
 631
 632/*
 633 * sysfs visibility
 634 */
 635
 636static void smu_expose_childs(struct work_struct *unused)
 637{
 638	struct device_node *np;
 639
 640	for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 641		if (of_device_is_compatible(np, "smu-sensors"))
 642			of_platform_device_create(np, "smu-sensors",
 643						  &smu->of_dev->dev);
 644}
 645
 646static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 647
 648static 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
 663static const struct of_device_id smu_platform_match[] =
 664{
 665	{
 666		.type		= "smu",
 667	},
 668	{},
 669};
 670
 671static struct platform_driver smu_of_platform_driver =
 672{
 673	.driver = {
 674		.name = "smu",
 675		.owner = THIS_MODULE,
 676		.of_match_table = smu_platform_match,
 677	},
 678	.probe		= smu_platform_probe,
 679};
 680
 681static int __init smu_init_sysfs(void)
 682{
 683	/*
 684	 * Due to sysfs bogosity, a sysdev is not a real device, so
 685	 * we should in fact create both if we want sysdev semantics
 686	 * for power management.
 687	 * For now, we don't power manage machines with an SMU chip,
 688	 * I'm a bit too far from figuring out how that works with those
 689	 * new chipsets, but that will come back and bite us
 690	 */
 691	platform_driver_register(&smu_of_platform_driver);
 692	return 0;
 693}
 694
 695device_initcall(smu_init_sysfs);
 696
 697struct platform_device *smu_get_ofdev(void)
 698{
 699	if (!smu)
 700		return NULL;
 701	return smu->of_dev;
 702}
 703
 704EXPORT_SYMBOL_GPL(smu_get_ofdev);
 705
 706/*
 707 * i2c interface
 708 */
 709
 710static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 711{
 712	void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
 713	void *misc = cmd->misc;
 714	unsigned long flags;
 715
 716	/* Check for read case */
 717	if (!fail && cmd->read) {
 718		if (cmd->pdata[0] < 1)
 719			fail = 1;
 720		else
 721			memcpy(cmd->info.data, &cmd->pdata[1],
 722			       cmd->info.datalen);
 723	}
 724
 725	DPRINTK("SMU: completing, success: %d\n", !fail);
 726
 727	/* Update status and mark no pending i2c command with lock
 728	 * held so nobody comes in while we dequeue an eventual
 729	 * pending next i2c command
 730	 */
 731	spin_lock_irqsave(&smu->lock, flags);
 732	smu->cmd_i2c_cur = NULL;
 733	wmb();
 734	cmd->status = fail ? -EIO : 0;
 735
 736	/* Is there another i2c command waiting ? */
 737	if (!list_empty(&smu->cmd_i2c_list)) {
 738		struct smu_i2c_cmd *newcmd;
 739
 740		/* Fetch it, new current, remove from list */
 741		newcmd = list_entry(smu->cmd_i2c_list.next,
 742				    struct smu_i2c_cmd, link);
 743		smu->cmd_i2c_cur = newcmd;
 744		list_del(&cmd->link);
 745
 746		/* Queue with low level smu */
 747		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 748		if (smu->cmd_cur == NULL)
 749			smu_start_cmd();
 750	}
 751	spin_unlock_irqrestore(&smu->lock, flags);
 752
 753	/* Call command completion handler if any */
 754	if (done)
 755		done(cmd, misc);
 756
 757}
 758
 759
 760static void smu_i2c_retry(unsigned long data)
 761{
 762	struct smu_i2c_cmd	*cmd = smu->cmd_i2c_cur;
 763
 764	DPRINTK("SMU: i2c failure, requeuing...\n");
 765
 766	/* requeue command simply by resetting reply_len */
 767	cmd->pdata[0] = 0xff;
 768	cmd->scmd.reply_len = sizeof(cmd->pdata);
 769	smu_queue_cmd(&cmd->scmd);
 770}
 771
 772
 773static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 774{
 775	struct smu_i2c_cmd	*cmd = misc;
 776	int			fail = 0;
 777
 778	DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
 779		cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
 780
 781	/* Check for possible status */
 782	if (scmd->status < 0)
 783		fail = 1;
 784	else if (cmd->read) {
 785		if (cmd->stage == 0)
 786			fail = cmd->pdata[0] != 0;
 787		else
 788			fail = cmd->pdata[0] >= 0x80;
 789	} else {
 790		fail = cmd->pdata[0] != 0;
 791	}
 792
 793	/* Handle failures by requeuing command, after 5ms interval
 794	 */
 795	if (fail && --cmd->retries > 0) {
 796		DPRINTK("SMU: i2c failure, starting timer...\n");
 797		BUG_ON(cmd != smu->cmd_i2c_cur);
 798		if (!smu_irq_inited) {
 799			mdelay(5);
 800			smu_i2c_retry(0);
 801			return;
 802		}
 803		mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
 804		return;
 805	}
 806
 807	/* If failure or stage 1, command is complete */
 808	if (fail || cmd->stage != 0) {
 809		smu_i2c_complete_command(cmd, fail);
 810		return;
 811	}
 812
 813	DPRINTK("SMU: going to stage 1\n");
 814
 815	/* Ok, initial command complete, now poll status */
 816	scmd->reply_buf = cmd->pdata;
 817	scmd->reply_len = sizeof(cmd->pdata);
 818	scmd->data_buf = cmd->pdata;
 819	scmd->data_len = 1;
 820	cmd->pdata[0] = 0;
 821	cmd->stage = 1;
 822	cmd->retries = 20;
 823	smu_queue_cmd(scmd);
 824}
 825
 826
 827int smu_queue_i2c(struct smu_i2c_cmd *cmd)
 828{
 829	unsigned long flags;
 830
 831	if (smu == NULL)
 832		return -ENODEV;
 833
 834	/* Fill most fields of scmd */
 835	cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
 836	cmd->scmd.done = smu_i2c_low_completion;
 837	cmd->scmd.misc = cmd;
 838	cmd->scmd.reply_buf = cmd->pdata;
 839	cmd->scmd.reply_len = sizeof(cmd->pdata);
 840	cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
 841	cmd->scmd.status = 1;
 842	cmd->stage = 0;
 843	cmd->pdata[0] = 0xff;
 844	cmd->retries = 20;
 845	cmd->status = 1;
 846
 847	/* Check transfer type, sanitize some "info" fields
 848	 * based on transfer type and do more checking
 849	 */
 850	cmd->info.caddr = cmd->info.devaddr;
 851	cmd->read = cmd->info.devaddr & 0x01;
 852	switch(cmd->info.type) {
 853	case SMU_I2C_TRANSFER_SIMPLE:
 854		memset(&cmd->info.sublen, 0, 4);
 855		break;
 856	case SMU_I2C_TRANSFER_COMBINED:
 857		cmd->info.devaddr &= 0xfe;
 858	case SMU_I2C_TRANSFER_STDSUB:
 859		if (cmd->info.sublen > 3)
 860			return -EINVAL;
 861		break;
 862	default:
 863		return -EINVAL;
 864	}
 865
 866	/* Finish setting up command based on transfer direction
 867	 */
 868	if (cmd->read) {
 869		if (cmd->info.datalen > SMU_I2C_READ_MAX)
 870			return -EINVAL;
 871		memset(cmd->info.data, 0xff, cmd->info.datalen);
 872		cmd->scmd.data_len = 9;
 873	} else {
 874		if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 875			return -EINVAL;
 876		cmd->scmd.data_len = 9 + cmd->info.datalen;
 877	}
 878
 879	DPRINTK("SMU: i2c enqueuing command\n");
 880	DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 881		cmd->read ? "read" : "write", cmd->info.datalen,
 882		cmd->info.bus, cmd->info.caddr,
 883		cmd->info.subaddr[0], cmd->info.type);
 884
 885
 886	/* Enqueue command in i2c list, and if empty, enqueue also in
 887	 * main command list
 888	 */
 889	spin_lock_irqsave(&smu->lock, flags);
 890	if (smu->cmd_i2c_cur == NULL) {
 891		smu->cmd_i2c_cur = cmd;
 892		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 893		if (smu->cmd_cur == NULL)
 894			smu_start_cmd();
 895	} else
 896		list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 897	spin_unlock_irqrestore(&smu->lock, flags);
 898
 899	return 0;
 900}
 901
 902/*
 903 * Handling of "partitions"
 904 */
 905
 906static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 907{
 908	DECLARE_COMPLETION_ONSTACK(comp);
 909	unsigned int chunk;
 910	struct smu_cmd cmd;
 911	int rc;
 912	u8 params[8];
 913
 914	/* We currently use a chunk size of 0xe. We could check the
 915	 * SMU firmware version and use bigger sizes though
 916	 */
 917	chunk = 0xe;
 918
 919	while (len) {
 920		unsigned int clen = min(len, chunk);
 921
 922		cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 923		cmd.data_len = 7;
 924		cmd.data_buf = params;
 925		cmd.reply_len = chunk;
 926		cmd.reply_buf = dest;
 927		cmd.done = smu_done_complete;
 928		cmd.misc = &comp;
 929		params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 930		params[1] = 0x4;
 931		*((u32 *)&params[2]) = addr;
 932		params[6] = clen;
 933
 934		rc = smu_queue_cmd(&cmd);
 935		if (rc)
 936			return rc;
 937		wait_for_completion(&comp);
 938		if (cmd.status != 0)
 939			return rc;
 940		if (cmd.reply_len != clen) {
 941			printk(KERN_DEBUG "SMU: short read in "
 942			       "smu_read_datablock, got: %d, want: %d\n",
 943			       cmd.reply_len, clen);
 944			return -EIO;
 945		}
 946		len -= clen;
 947		addr += clen;
 948		dest += clen;
 949	}
 950	return 0;
 951}
 952
 953static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 954{
 955	DECLARE_COMPLETION_ONSTACK(comp);
 956	struct smu_simple_cmd cmd;
 957	unsigned int addr, len, tlen;
 958	struct smu_sdbp_header *hdr;
 959	struct property *prop;
 960
 961	/* First query the partition info */
 962	DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 963	smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 964			 smu_done_complete, &comp,
 965			 SMU_CMD_PARTITION_LATEST, id);
 966	wait_for_completion(&comp);
 967	DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 968		cmd.cmd.status, cmd.cmd.reply_len);
 969
 970	/* Partition doesn't exist (or other error) */
 971	if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 972		return NULL;
 973
 974	/* Fetch address and length from reply */
 975	addr = *((u16 *)cmd.buffer);
 976	len = cmd.buffer[3] << 2;
 977	/* Calucluate total length to allocate, including the 17 bytes
 978	 * for "sdb-partition-XX" that we append at the end of the buffer
 979	 */
 980	tlen = sizeof(struct property) + len + 18;
 981
 982	prop = kzalloc(tlen, GFP_KERNEL);
 983	if (prop == NULL)
 984		return NULL;
 985	hdr = (struct smu_sdbp_header *)(prop + 1);
 986	prop->name = ((char *)prop) + tlen - 18;
 987	sprintf(prop->name, "sdb-partition-%02x", id);
 988	prop->length = len;
 989	prop->value = hdr;
 990	prop->next = NULL;
 991
 992	/* Read the datablock */
 993	if (smu_read_datablock((u8 *)hdr, addr, len)) {
 994		printk(KERN_DEBUG "SMU: datablock read failed while reading "
 995		       "partition %02x !\n", id);
 996		goto failure;
 997	}
 998
 999	/* Got it, check a few things and create the property */
1000	if (hdr->id != id) {
1001		printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1002		       "%02x !\n", id, hdr->id);
1003		goto failure;
1004	}
1005	if (prom_add_property(smu->of_node, prop)) {
1006		printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1007		       "property !\n", id);
1008		goto failure;
1009	}
1010
1011	return hdr;
1012 failure:
1013	kfree(prop);
1014	return NULL;
1015}
1016
1017/* Note: Only allowed to return error code in pointers (using ERR_PTR)
1018 * when interruptible is 1
1019 */
1020const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1021		unsigned int *size, int interruptible)
1022{
1023	char pname[32];
1024	const struct smu_sdbp_header *part;
1025
1026	if (!smu)
1027		return NULL;
1028
1029	sprintf(pname, "sdb-partition-%02x", id);
1030
1031	DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1032
1033	if (interruptible) {
1034		int rc;
1035		rc = mutex_lock_interruptible(&smu_part_access);
1036		if (rc)
1037			return ERR_PTR(rc);
1038	} else
1039		mutex_lock(&smu_part_access);
1040
1041	part = of_get_property(smu->of_node, pname, size);
1042	if (part == NULL) {
1043		DPRINTK("trying to extract from SMU ...\n");
1044		part = smu_create_sdb_partition(id);
1045		if (part != NULL && size)
1046			*size = part->len << 2;
1047	}
1048	mutex_unlock(&smu_part_access);
1049	return part;
1050}
1051
1052const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1053{
1054	return __smu_get_sdb_partition(id, size, 0);
1055}
1056EXPORT_SYMBOL(smu_get_sdb_partition);
1057
1058
1059/*
1060 * Userland driver interface
1061 */
1062
1063
1064static LIST_HEAD(smu_clist);
1065static DEFINE_SPINLOCK(smu_clist_lock);
1066
1067enum smu_file_mode {
1068	smu_file_commands,
1069	smu_file_events,
1070	smu_file_closing
1071};
1072
1073struct smu_private
1074{
1075	struct list_head	list;
1076	enum smu_file_mode	mode;
1077	int			busy;
1078	struct smu_cmd		cmd;
1079	spinlock_t		lock;
1080	wait_queue_head_t	wait;
1081	u8			buffer[SMU_MAX_DATA];
1082};
1083
1084
1085static int smu_open(struct inode *inode, struct file *file)
1086{
1087	struct smu_private *pp;
1088	unsigned long flags;
1089
1090	pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1091	if (pp == 0)
1092		return -ENOMEM;
1093	spin_lock_init(&pp->lock);
1094	pp->mode = smu_file_commands;
1095	init_waitqueue_head(&pp->wait);
1096
1097	mutex_lock(&smu_mutex);
1098	spin_lock_irqsave(&smu_clist_lock, flags);
1099	list_add(&pp->list, &smu_clist);
1100	spin_unlock_irqrestore(&smu_clist_lock, flags);
1101	file->private_data = pp;
1102	mutex_unlock(&smu_mutex);
1103
1104	return 0;
1105}
1106
1107
1108static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1109{
1110	struct smu_private *pp = misc;
1111
1112	wake_up_all(&pp->wait);
1113}
1114
1115
1116static ssize_t smu_write(struct file *file, const char __user *buf,
1117			 size_t count, loff_t *ppos)
1118{
1119	struct smu_private *pp = file->private_data;
1120	unsigned long flags;
1121	struct smu_user_cmd_hdr hdr;
1122	int rc = 0;
1123
1124	if (pp->busy)
1125		return -EBUSY;
1126	else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1127		return -EFAULT;
1128	else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1129		pp->mode = smu_file_events;
1130		return 0;
1131	} else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1132		const struct smu_sdbp_header *part;
1133		part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1134		if (part == NULL)
1135			return -EINVAL;
1136		else if (IS_ERR(part))
1137			return PTR_ERR(part);
1138		return 0;
1139	} else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1140		return -EINVAL;
1141	else if (pp->mode != smu_file_commands)
1142		return -EBADFD;
1143	else if (hdr.data_len > SMU_MAX_DATA)
1144		return -EINVAL;
1145
1146	spin_lock_irqsave(&pp->lock, flags);
1147	if (pp->busy) {
1148		spin_unlock_irqrestore(&pp->lock, flags);
1149		return -EBUSY;
1150	}
1151	pp->busy = 1;
1152	pp->cmd.status = 1;
1153	spin_unlock_irqrestore(&pp->lock, flags);
1154
1155	if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1156		pp->busy = 0;
1157		return -EFAULT;
1158	}
1159
1160	pp->cmd.cmd = hdr.cmd;
1161	pp->cmd.data_len = hdr.data_len;
1162	pp->cmd.reply_len = SMU_MAX_DATA;
1163	pp->cmd.data_buf = pp->buffer;
1164	pp->cmd.reply_buf = pp->buffer;
1165	pp->cmd.done = smu_user_cmd_done;
1166	pp->cmd.misc = pp;
1167	rc = smu_queue_cmd(&pp->cmd);
1168	if (rc < 0)
1169		return rc;
1170	return count;
1171}
1172
1173
1174static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1175				char __user *buf, size_t count)
1176{
1177	DECLARE_WAITQUEUE(wait, current);
1178	struct smu_user_reply_hdr hdr;
1179	unsigned long flags;
1180	int size, rc = 0;
1181
1182	if (!pp->busy)
1183		return 0;
1184	if (count < sizeof(struct smu_user_reply_hdr))
1185		return -EOVERFLOW;
1186	spin_lock_irqsave(&pp->lock, flags);
1187	if (pp->cmd.status == 1) {
1188		if (file->f_flags & O_NONBLOCK) {
1189			spin_unlock_irqrestore(&pp->lock, flags);
1190			return -EAGAIN;
1191		}
1192		add_wait_queue(&pp->wait, &wait);
1193		for (;;) {
1194			set_current_state(TASK_INTERRUPTIBLE);
1195			rc = 0;
1196			if (pp->cmd.status != 1)
1197				break;
1198			rc = -ERESTARTSYS;
1199			if (signal_pending(current))
1200				break;
1201			spin_unlock_irqrestore(&pp->lock, flags);
1202			schedule();
1203			spin_lock_irqsave(&pp->lock, flags);
1204		}
1205		set_current_state(TASK_RUNNING);
1206		remove_wait_queue(&pp->wait, &wait);
1207	}
1208	spin_unlock_irqrestore(&pp->lock, flags);
1209	if (rc)
1210		return rc;
1211	if (pp->cmd.status != 0)
1212		pp->cmd.reply_len = 0;
1213	size = sizeof(hdr) + pp->cmd.reply_len;
1214	if (count < size)
1215		size = count;
1216	rc = size;
1217	hdr.status = pp->cmd.status;
1218	hdr.reply_len = pp->cmd.reply_len;
1219	if (copy_to_user(buf, &hdr, sizeof(hdr)))
1220		return -EFAULT;
1221	size -= sizeof(hdr);
1222	if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1223		return -EFAULT;
1224	pp->busy = 0;
1225
1226	return rc;
1227}
1228
1229
1230static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1231			       char __user *buf, size_t count)
1232{
1233	/* Not implemented */
1234	msleep_interruptible(1000);
1235	return 0;
1236}
1237
1238
1239static ssize_t smu_read(struct file *file, char __user *buf,
1240			size_t count, loff_t *ppos)
1241{
1242	struct smu_private *pp = file->private_data;
1243
1244	if (pp->mode == smu_file_commands)
1245		return smu_read_command(file, pp, buf, count);
1246	if (pp->mode == smu_file_events)
1247		return smu_read_events(file, pp, buf, count);
1248
1249	return -EBADFD;
1250}
1251
1252static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1253{
1254	struct smu_private *pp = file->private_data;
1255	unsigned int mask = 0;
1256	unsigned long flags;
1257
1258	if (pp == 0)
1259		return 0;
1260
1261	if (pp->mode == smu_file_commands) {
1262		poll_wait(file, &pp->wait, wait);
1263
1264		spin_lock_irqsave(&pp->lock, flags);
1265		if (pp->busy && pp->cmd.status != 1)
1266			mask |= POLLIN;
1267		spin_unlock_irqrestore(&pp->lock, flags);
1268	} if (pp->mode == smu_file_events) {
1269		/* Not yet implemented */
1270	}
1271	return mask;
1272}
1273
1274static int smu_release(struct inode *inode, struct file *file)
1275{
1276	struct smu_private *pp = file->private_data;
1277	unsigned long flags;
1278	unsigned int busy;
1279
1280	if (pp == 0)
1281		return 0;
1282
1283	file->private_data = NULL;
1284
1285	/* Mark file as closing to avoid races with new request */
1286	spin_lock_irqsave(&pp->lock, flags);
1287	pp->mode = smu_file_closing;
1288	busy = pp->busy;
1289
1290	/* Wait for any pending request to complete */
1291	if (busy && pp->cmd.status == 1) {
1292		DECLARE_WAITQUEUE(wait, current);
1293
1294		add_wait_queue(&pp->wait, &wait);
1295		for (;;) {
1296			set_current_state(TASK_UNINTERRUPTIBLE);
1297			if (pp->cmd.status != 1)
1298				break;
1299			spin_unlock_irqrestore(&pp->lock, flags);
1300			schedule();
1301			spin_lock_irqsave(&pp->lock, flags);
1302		}
1303		set_current_state(TASK_RUNNING);
1304		remove_wait_queue(&pp->wait, &wait);
1305	}
1306	spin_unlock_irqrestore(&pp->lock, flags);
1307
1308	spin_lock_irqsave(&smu_clist_lock, flags);
1309	list_del(&pp->list);
1310	spin_unlock_irqrestore(&smu_clist_lock, flags);
1311	kfree(pp);
1312
1313	return 0;
1314}
1315
1316
1317static const struct file_operations smu_device_fops = {
1318	.llseek		= no_llseek,
1319	.read		= smu_read,
1320	.write		= smu_write,
1321	.poll		= smu_fpoll,
1322	.open		= smu_open,
1323	.release	= smu_release,
1324};
1325
1326static struct miscdevice pmu_device = {
1327	MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1328};
1329
1330static int smu_device_init(void)
1331{
1332	if (!smu)
1333		return -ENODEV;
1334	if (misc_register(&pmu_device) < 0)
1335		printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1336	return 0;
1337}
1338device_initcall(smu_device_init);
v3.5.6
   1/*
   2 * PowerMac G5 SMU driver
   3 *
   4 * Copyright 2004 J. Mayer <l_indien@magic.fr>
   5 * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   6 *
   7 * Released under the term of the GNU GPL v2.
   8 */
   9
  10/*
  11 * TODO:
  12 *  - maybe add timeout to commands ?
  13 *  - blocking version of time functions
  14 *  - polling version of i2c commands (including timer that works with
  15 *    interrupts off)
  16 *  - maybe avoid some data copies with i2c by directly using the smu cmd
  17 *    buffer and a lower level internal interface
  18 *  - understand SMU -> CPU events and implement reception of them via
  19 *    the userland interface
  20 */
  21
  22#include <linux/types.h>
  23#include <linux/kernel.h>
  24#include <linux/device.h>
  25#include <linux/dmapool.h>
  26#include <linux/bootmem.h>
  27#include <linux/vmalloc.h>
  28#include <linux/highmem.h>
  29#include <linux/jiffies.h>
  30#include <linux/interrupt.h>
  31#include <linux/rtc.h>
  32#include <linux/completion.h>
  33#include <linux/miscdevice.h>
  34#include <linux/delay.h>
 
  35#include <linux/poll.h>
  36#include <linux/mutex.h>
  37#include <linux/of_device.h>
  38#include <linux/of_platform.h>
  39#include <linux/slab.h>
  40
  41#include <asm/byteorder.h>
  42#include <asm/io.h>
  43#include <asm/prom.h>
  44#include <asm/machdep.h>
  45#include <asm/pmac_feature.h>
  46#include <asm/smu.h>
  47#include <asm/sections.h>
  48#include <asm/abs_addr.h>
  49#include <asm/uaccess.h>
  50
  51#define VERSION "0.7"
  52#define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
  53
  54#undef DEBUG_SMU
  55
  56#ifdef DEBUG_SMU
  57#define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
  58#else
  59#define DPRINTK(fmt, args...) do { } while (0)
  60#endif
  61
  62/*
  63 * This is the command buffer passed to the SMU hardware
  64 */
  65#define SMU_MAX_DATA	254
  66
  67struct smu_cmd_buf {
  68	u8 cmd;
  69	u8 length;
  70	u8 data[SMU_MAX_DATA];
  71};
  72
  73struct smu_device {
  74	spinlock_t		lock;
  75	struct device_node	*of_node;
  76	struct platform_device	*of_dev;
  77	int			doorbell;	/* doorbell gpio */
  78	u32 __iomem		*db_buf;	/* doorbell buffer */
  79	struct device_node	*db_node;
  80	unsigned int		db_irq;
  81	int			msg;
  82	struct device_node	*msg_node;
  83	unsigned int		msg_irq;
  84	struct smu_cmd_buf	*cmd_buf;	/* command buffer virtual */
  85	u32			cmd_buf_abs;	/* command buffer absolute */
  86	struct list_head	cmd_list;
  87	struct smu_cmd		*cmd_cur;	/* pending command */
  88	int			broken_nap;
  89	struct list_head	cmd_i2c_list;
  90	struct smu_i2c_cmd	*cmd_i2c_cur;	/* pending i2c command */
  91	struct timer_list	i2c_timer;
  92};
  93
  94/*
  95 * I don't think there will ever be more than one SMU, so
  96 * for now, just hard code that
  97 */
  98static DEFINE_MUTEX(smu_mutex);
  99static struct smu_device	*smu;
 100static DEFINE_MUTEX(smu_part_access);
 101static int smu_irq_inited;
 102
 103static void smu_i2c_retry(unsigned long data);
 104
 105/*
 106 * SMU driver low level stuff
 107 */
 108
 109static 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: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 125		((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
 126		((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
 127		((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
 128		((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
 129
 130	/* Fill the SMU command buffer */
 131	smu->cmd_buf->cmd = cmd->cmd;
 132	smu->cmd_buf->length = cmd->data_len;
 133	memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
 134
 135	/* Flush command and data to RAM */
 136	faddr = (unsigned long)smu->cmd_buf;
 137	fend = faddr + smu->cmd_buf->length + 2;
 138	flush_inval_dcache_range(faddr, fend);
 139
 140
 141	/* We also disable NAP mode for the duration of the command
 142	 * on U3 based machines.
 143	 * This is slightly racy as it can be written back to 1 by a sysctl
 144	 * but that never happens in practice. There seem to be an issue with
 145	 * U3 based machines such as the iMac G5 where napping for the
 146	 * whole duration of the command prevents the SMU from fetching it
 147	 * from memory. This might be related to the strange i2c based
 148	 * mechanism the SMU uses to access memory.
 149	 */
 150	if (smu->broken_nap)
 151		powersave_nap = 0;
 152
 153	/* This isn't exactly a DMA mapping here, I suspect
 154	 * the SMU is actually communicating with us via i2c to the
 155	 * northbridge or the CPU to access RAM.
 156	 */
 157	writel(smu->cmd_buf_abs, smu->db_buf);
 158
 159	/* Ring the SMU doorbell */
 160	pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 161}
 162
 163
 164static irqreturn_t smu_db_intr(int irq, void *arg)
 165{
 166	unsigned long flags;
 167	struct smu_cmd *cmd;
 168	void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
 169	void *misc = NULL;
 170	u8 gpio;
 171	int rc = 0;
 172
 173	/* SMU completed the command, well, we hope, let's make sure
 174	 * of it
 175	 */
 176	spin_lock_irqsave(&smu->lock, flags);
 177
 178	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 179	if ((gpio & 7) != 7) {
 180		spin_unlock_irqrestore(&smu->lock, flags);
 181		return IRQ_HANDLED;
 182	}
 183
 184	cmd = smu->cmd_cur;
 185	smu->cmd_cur = NULL;
 186	if (cmd == NULL)
 187		goto bail;
 188
 189	if (rc == 0) {
 190		unsigned long faddr;
 191		int reply_len;
 192		u8 ack;
 193
 194		/* CPU might have brought back the cache line, so we need
 195		 * to flush again before peeking at the SMU response. We
 196		 * flush the entire buffer for now as we haven't read the
 197		 * reply length (it's only 2 cache lines anyway)
 198		 */
 199		faddr = (unsigned long)smu->cmd_buf;
 200		flush_inval_dcache_range(faddr, faddr + 256);
 201
 202		/* Now check ack */
 203		ack = (~cmd->cmd) & 0xff;
 204		if (ack != smu->cmd_buf->cmd) {
 205			DPRINTK("SMU: incorrect ack, want %x got %x\n",
 206				ack, smu->cmd_buf->cmd);
 207			rc = -EIO;
 208		}
 209		reply_len = rc == 0 ? smu->cmd_buf->length : 0;
 210		DPRINTK("SMU: reply len: %d\n", reply_len);
 211		if (reply_len > cmd->reply_len) {
 212			printk(KERN_WARNING "SMU: reply buffer too small,"
 213			       "got %d bytes for a %d bytes buffer\n",
 214			       reply_len, cmd->reply_len);
 215			reply_len = cmd->reply_len;
 216		}
 217		cmd->reply_len = reply_len;
 218		if (cmd->reply_buf && reply_len)
 219			memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
 220	}
 221
 222	/* Now complete the command. Write status last in order as we lost
 223	 * ownership of the command structure as soon as it's no longer -1
 224	 */
 225	done = cmd->done;
 226	misc = cmd->misc;
 227	mb();
 228	cmd->status = rc;
 229
 230	/* Re-enable NAP mode */
 231	if (smu->broken_nap)
 232		powersave_nap = 1;
 233 bail:
 234	/* Start next command if any */
 235	smu_start_cmd();
 236	spin_unlock_irqrestore(&smu->lock, flags);
 237
 238	/* Call command completion handler if any */
 239	if (done)
 240		done(cmd, misc);
 241
 242	/* It's an edge interrupt, nothing to do */
 243	return IRQ_HANDLED;
 244}
 245
 246
 247static irqreturn_t smu_msg_intr(int irq, void *arg)
 248{
 249	/* I don't quite know what to do with this one, we seem to never
 250	 * receive it, so I suspect we have to arm it someway in the SMU
 251	 * to start getting events that way.
 252	 */
 253
 254	printk(KERN_INFO "SMU: message interrupt !\n");
 255
 256	/* It's an edge interrupt, nothing to do */
 257	return IRQ_HANDLED;
 258}
 259
 260
 261/*
 262 * Queued command management.
 263 *
 264 */
 265
 266int smu_queue_cmd(struct smu_cmd *cmd)
 267{
 268	unsigned long flags;
 269
 270	if (smu == NULL)
 271		return -ENODEV;
 272	if (cmd->data_len > SMU_MAX_DATA ||
 273	    cmd->reply_len > SMU_MAX_DATA)
 274		return -EINVAL;
 275
 276	cmd->status = 1;
 277	spin_lock_irqsave(&smu->lock, flags);
 278	list_add_tail(&cmd->link, &smu->cmd_list);
 279	if (smu->cmd_cur == NULL)
 280		smu_start_cmd();
 281	spin_unlock_irqrestore(&smu->lock, flags);
 282
 283	/* Workaround for early calls when irq isn't available */
 284	if (!smu_irq_inited || smu->db_irq == NO_IRQ)
 285		smu_spinwait_cmd(cmd);
 286
 287	return 0;
 288}
 289EXPORT_SYMBOL(smu_queue_cmd);
 290
 291
 292int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
 293		     unsigned int data_len,
 294		     void (*done)(struct smu_cmd *cmd, void *misc),
 295		     void *misc, ...)
 296{
 297	struct smu_cmd *cmd = &scmd->cmd;
 298	va_list list;
 299	int i;
 300
 301	if (data_len > sizeof(scmd->buffer))
 302		return -EINVAL;
 303
 304	memset(scmd, 0, sizeof(*scmd));
 305	cmd->cmd = command;
 306	cmd->data_len = data_len;
 307	cmd->data_buf = scmd->buffer;
 308	cmd->reply_len = sizeof(scmd->buffer);
 309	cmd->reply_buf = scmd->buffer;
 310	cmd->done = done;
 311	cmd->misc = misc;
 312
 313	va_start(list, misc);
 314	for (i = 0; i < data_len; ++i)
 315		scmd->buffer[i] = (u8)va_arg(list, int);
 316	va_end(list);
 317
 318	return smu_queue_cmd(cmd);
 319}
 320EXPORT_SYMBOL(smu_queue_simple);
 321
 322
 323void smu_poll(void)
 324{
 325	u8 gpio;
 326
 327	if (smu == NULL)
 328		return;
 329
 330	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
 331	if ((gpio & 7) == 7)
 332		smu_db_intr(smu->db_irq, smu);
 333}
 334EXPORT_SYMBOL(smu_poll);
 335
 336
 337void smu_done_complete(struct smu_cmd *cmd, void *misc)
 338{
 339	struct completion *comp = misc;
 340
 341	complete(comp);
 342}
 343EXPORT_SYMBOL(smu_done_complete);
 344
 345
 346void smu_spinwait_cmd(struct smu_cmd *cmd)
 347{
 348	while(cmd->status == 1)
 349		smu_poll();
 350}
 351EXPORT_SYMBOL(smu_spinwait_cmd);
 352
 353
 354/* RTC low level commands */
 355static inline int bcd2hex (int n)
 356{
 357	return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 358}
 359
 360
 361static inline int hex2bcd (int n)
 362{
 363	return ((n / 10) << 4) + (n % 10);
 364}
 365
 366
 367static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 368					struct rtc_time *time)
 369{
 370	cmd_buf->cmd = 0x8e;
 371	cmd_buf->length = 8;
 372	cmd_buf->data[0] = 0x80;
 373	cmd_buf->data[1] = hex2bcd(time->tm_sec);
 374	cmd_buf->data[2] = hex2bcd(time->tm_min);
 375	cmd_buf->data[3] = hex2bcd(time->tm_hour);
 376	cmd_buf->data[4] = time->tm_wday;
 377	cmd_buf->data[5] = hex2bcd(time->tm_mday);
 378	cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
 379	cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 380}
 381
 382
 383int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 384{
 385	struct smu_simple_cmd cmd;
 386	int rc;
 387
 388	if (smu == NULL)
 389		return -ENODEV;
 390
 391	memset(time, 0, sizeof(struct rtc_time));
 392	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
 393			      SMU_CMD_RTC_GET_DATETIME);
 394	if (rc)
 395		return rc;
 396	smu_spinwait_simple(&cmd);
 397
 398	time->tm_sec = bcd2hex(cmd.buffer[0]);
 399	time->tm_min = bcd2hex(cmd.buffer[1]);
 400	time->tm_hour = bcd2hex(cmd.buffer[2]);
 401	time->tm_wday = bcd2hex(cmd.buffer[3]);
 402	time->tm_mday = bcd2hex(cmd.buffer[4]);
 403	time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
 404	time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
 405
 406	return 0;
 407}
 408
 409
 410int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 411{
 412	struct smu_simple_cmd cmd;
 413	int rc;
 414
 415	if (smu == NULL)
 416		return -ENODEV;
 417
 418	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
 419			      SMU_CMD_RTC_SET_DATETIME,
 420			      hex2bcd(time->tm_sec),
 421			      hex2bcd(time->tm_min),
 422			      hex2bcd(time->tm_hour),
 423			      time->tm_wday,
 424			      hex2bcd(time->tm_mday),
 425			      hex2bcd(time->tm_mon) + 1,
 426			      hex2bcd(time->tm_year - 100));
 427	if (rc)
 428		return rc;
 429	smu_spinwait_simple(&cmd);
 430
 431	return 0;
 432}
 433
 434
 435void smu_shutdown(void)
 436{
 437	struct smu_simple_cmd cmd;
 438
 439	if (smu == NULL)
 440		return;
 441
 442	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
 443			     'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
 444		return;
 445	smu_spinwait_simple(&cmd);
 446	for (;;)
 447		;
 448}
 449
 450
 451void smu_restart(void)
 452{
 453	struct smu_simple_cmd cmd;
 454
 455	if (smu == NULL)
 456		return;
 457
 458	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
 459			     'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
 460		return;
 461	smu_spinwait_simple(&cmd);
 462	for (;;)
 463		;
 464}
 465
 466
 467int smu_present(void)
 468{
 469	return smu != NULL;
 470}
 471EXPORT_SYMBOL(smu_present);
 472
 473
 474int __init smu_init (void)
 475{
 476	struct device_node *np;
 477	const u32 *data;
 478	int ret = 0;
 479
 480        np = of_find_node_by_type(NULL, "smu");
 481        if (np == NULL)
 482		return -ENODEV;
 483
 484	printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 485
 486	if (smu_cmdbuf_abs == 0) {
 487		printk(KERN_ERR "SMU: Command buffer not allocated !\n");
 488		ret = -EINVAL;
 489		goto fail_np;
 490	}
 491
 492	smu = alloc_bootmem(sizeof(struct smu_device));
 493
 494	spin_lock_init(&smu->lock);
 495	INIT_LIST_HEAD(&smu->cmd_list);
 496	INIT_LIST_HEAD(&smu->cmd_i2c_list);
 497	smu->of_node = np;
 498	smu->db_irq = NO_IRQ;
 499	smu->msg_irq = NO_IRQ;
 500
 501	/* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
 502	 * 32 bits value safely
 503	 */
 504	smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
 505	smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
 506
 507	smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
 508	if (smu->db_node == NULL) {
 509		printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
 510		ret = -ENXIO;
 511		goto fail_bootmem;
 512	}
 513	data = of_get_property(smu->db_node, "reg", NULL);
 514	if (data == NULL) {
 515		printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 516		ret = -ENXIO;
 517		goto fail_db_node;
 518	}
 519
 520	/* Current setup has one doorbell GPIO that does both doorbell
 521	 * and ack. GPIOs are at 0x50, best would be to find that out
 522	 * in the device-tree though.
 523	 */
 524	smu->doorbell = *data;
 525	if (smu->doorbell < 0x50)
 526		smu->doorbell += 0x50;
 527
 528	/* Now look for the smu-interrupt GPIO */
 529	do {
 530		smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
 531		if (smu->msg_node == NULL)
 532			break;
 533		data = of_get_property(smu->msg_node, "reg", NULL);
 534		if (data == NULL) {
 535			of_node_put(smu->msg_node);
 536			smu->msg_node = NULL;
 537			break;
 538		}
 539		smu->msg = *data;
 540		if (smu->msg < 0x50)
 541			smu->msg += 0x50;
 542	} while(0);
 543
 544	/* Doorbell buffer is currently hard-coded, I didn't find a proper
 545	 * device-tree entry giving the address. Best would probably to use
 546	 * an offset for K2 base though, but let's do it that way for now.
 547	 */
 548	smu->db_buf = ioremap(0x8000860c, 0x1000);
 549	if (smu->db_buf == NULL) {
 550		printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
 551		ret = -ENXIO;
 552		goto fail_msg_node;
 553	}
 554
 555	/* U3 has an issue with NAP mode when issuing SMU commands */
 556	smu->broken_nap = pmac_get_uninorth_variant() < 4;
 557	if (smu->broken_nap)
 558		printk(KERN_INFO "SMU: using NAP mode workaround\n");
 559
 560	sys_ctrler = SYS_CTRLER_SMU;
 561	return 0;
 562
 563fail_msg_node:
 564	if (smu->msg_node)
 565		of_node_put(smu->msg_node);
 566fail_db_node:
 567	of_node_put(smu->db_node);
 568fail_bootmem:
 569	free_bootmem((unsigned long)smu, sizeof(struct smu_device));
 570	smu = NULL;
 571fail_np:
 572	of_node_put(np);
 573	return ret;
 574}
 575
 576
 577static int smu_late_init(void)
 578{
 579	if (!smu)
 580		return 0;
 581
 582	init_timer(&smu->i2c_timer);
 583	smu->i2c_timer.function = smu_i2c_retry;
 584	smu->i2c_timer.data = (unsigned long)smu;
 585
 586	if (smu->db_node) {
 587		smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
 588		if (smu->db_irq == NO_IRQ)
 589			printk(KERN_ERR "smu: failed to map irq for node %s\n",
 590			       smu->db_node->full_name);
 591	}
 592	if (smu->msg_node) {
 593		smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
 594		if (smu->msg_irq == NO_IRQ)
 595			printk(KERN_ERR "smu: failed to map irq for node %s\n",
 596			       smu->msg_node->full_name);
 597	}
 598
 599	/*
 600	 * Try to request the interrupts
 601	 */
 602
 603	if (smu->db_irq != NO_IRQ) {
 604		if (request_irq(smu->db_irq, smu_db_intr,
 605				IRQF_SHARED, "SMU doorbell", smu) < 0) {
 606			printk(KERN_WARNING "SMU: can't "
 607			       "request interrupt %d\n",
 608			       smu->db_irq);
 609			smu->db_irq = NO_IRQ;
 610		}
 611	}
 612
 613	if (smu->msg_irq != NO_IRQ) {
 614		if (request_irq(smu->msg_irq, smu_msg_intr,
 615				IRQF_SHARED, "SMU message", smu) < 0) {
 616			printk(KERN_WARNING "SMU: can't "
 617			       "request interrupt %d\n",
 618			       smu->msg_irq);
 619			smu->msg_irq = NO_IRQ;
 620		}
 621	}
 622
 623	smu_irq_inited = 1;
 624	return 0;
 625}
 626/* This has to be before arch_initcall as the low i2c stuff relies on the
 627 * above having been done before we reach arch_initcalls
 628 */
 629core_initcall(smu_late_init);
 630
 631/*
 632 * sysfs visibility
 633 */
 634
 635static void smu_expose_childs(struct work_struct *unused)
 636{
 637	struct device_node *np;
 638
 639	for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
 640		if (of_device_is_compatible(np, "smu-sensors"))
 641			of_platform_device_create(np, "smu-sensors",
 642						  &smu->of_dev->dev);
 643}
 644
 645static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
 646
 647static int smu_platform_probe(struct platform_device* dev)
 648{
 649	if (!smu)
 650		return -ENODEV;
 651	smu->of_dev = dev;
 652
 653	/*
 654	 * Ok, we are matched, now expose all i2c busses. We have to defer
 655	 * that unfortunately or it would deadlock inside the device model
 656	 */
 657	schedule_work(&smu_expose_childs_work);
 658
 659	return 0;
 660}
 661
 662static const struct of_device_id smu_platform_match[] =
 663{
 664	{
 665		.type		= "smu",
 666	},
 667	{},
 668};
 669
 670static struct platform_driver smu_of_platform_driver =
 671{
 672	.driver = {
 673		.name = "smu",
 674		.owner = THIS_MODULE,
 675		.of_match_table = smu_platform_match,
 676	},
 677	.probe		= smu_platform_probe,
 678};
 679
 680static 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
 691device_initcall(smu_init_sysfs);
 692
 693struct platform_device *smu_get_ofdev(void)
 694{
 695	if (!smu)
 696		return NULL;
 697	return smu->of_dev;
 698}
 699
 700EXPORT_SYMBOL_GPL(smu_get_ofdev);
 701
 702/*
 703 * i2c interface
 704 */
 705
 706static 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
 756static void smu_i2c_retry(unsigned long data)
 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
 769static 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(0);
 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
 823int 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		memset(&cmd->info.sublen, 0, 4);
 851		break;
 852	case SMU_I2C_TRANSFER_COMBINED:
 853		cmd->info.devaddr &= 0xfe;
 854	case SMU_I2C_TRANSFER_STDSUB:
 855		if (cmd->info.sublen > 3)
 856			return -EINVAL;
 857		break;
 858	default:
 859		return -EINVAL;
 860	}
 861
 862	/* Finish setting up command based on transfer direction
 863	 */
 864	if (cmd->read) {
 865		if (cmd->info.datalen > SMU_I2C_READ_MAX)
 866			return -EINVAL;
 867		memset(cmd->info.data, 0xff, cmd->info.datalen);
 868		cmd->scmd.data_len = 9;
 869	} else {
 870		if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
 871			return -EINVAL;
 872		cmd->scmd.data_len = 9 + cmd->info.datalen;
 873	}
 874
 875	DPRINTK("SMU: i2c enqueuing command\n");
 876	DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
 877		cmd->read ? "read" : "write", cmd->info.datalen,
 878		cmd->info.bus, cmd->info.caddr,
 879		cmd->info.subaddr[0], cmd->info.type);
 880
 881
 882	/* Enqueue command in i2c list, and if empty, enqueue also in
 883	 * main command list
 884	 */
 885	spin_lock_irqsave(&smu->lock, flags);
 886	if (smu->cmd_i2c_cur == NULL) {
 887		smu->cmd_i2c_cur = cmd;
 888		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
 889		if (smu->cmd_cur == NULL)
 890			smu_start_cmd();
 891	} else
 892		list_add_tail(&cmd->link, &smu->cmd_i2c_list);
 893	spin_unlock_irqrestore(&smu->lock, flags);
 894
 895	return 0;
 896}
 897
 898/*
 899 * Handling of "partitions"
 900 */
 901
 902static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
 903{
 904	DECLARE_COMPLETION_ONSTACK(comp);
 905	unsigned int chunk;
 906	struct smu_cmd cmd;
 907	int rc;
 908	u8 params[8];
 909
 910	/* We currently use a chunk size of 0xe. We could check the
 911	 * SMU firmware version and use bigger sizes though
 912	 */
 913	chunk = 0xe;
 914
 915	while (len) {
 916		unsigned int clen = min(len, chunk);
 917
 918		cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
 919		cmd.data_len = 7;
 920		cmd.data_buf = params;
 921		cmd.reply_len = chunk;
 922		cmd.reply_buf = dest;
 923		cmd.done = smu_done_complete;
 924		cmd.misc = &comp;
 925		params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
 926		params[1] = 0x4;
 927		*((u32 *)&params[2]) = addr;
 928		params[6] = clen;
 929
 930		rc = smu_queue_cmd(&cmd);
 931		if (rc)
 932			return rc;
 933		wait_for_completion(&comp);
 934		if (cmd.status != 0)
 935			return rc;
 936		if (cmd.reply_len != clen) {
 937			printk(KERN_DEBUG "SMU: short read in "
 938			       "smu_read_datablock, got: %d, want: %d\n",
 939			       cmd.reply_len, clen);
 940			return -EIO;
 941		}
 942		len -= clen;
 943		addr += clen;
 944		dest += clen;
 945	}
 946	return 0;
 947}
 948
 949static struct smu_sdbp_header *smu_create_sdb_partition(int id)
 950{
 951	DECLARE_COMPLETION_ONSTACK(comp);
 952	struct smu_simple_cmd cmd;
 953	unsigned int addr, len, tlen;
 954	struct smu_sdbp_header *hdr;
 955	struct property *prop;
 956
 957	/* First query the partition info */
 958	DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
 959	smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
 960			 smu_done_complete, &comp,
 961			 SMU_CMD_PARTITION_LATEST, id);
 962	wait_for_completion(&comp);
 963	DPRINTK("SMU: done, status: %d, reply_len: %d\n",
 964		cmd.cmd.status, cmd.cmd.reply_len);
 965
 966	/* Partition doesn't exist (or other error) */
 967	if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
 968		return NULL;
 969
 970	/* Fetch address and length from reply */
 971	addr = *((u16 *)cmd.buffer);
 972	len = cmd.buffer[3] << 2;
 973	/* Calucluate total length to allocate, including the 17 bytes
 974	 * for "sdb-partition-XX" that we append at the end of the buffer
 975	 */
 976	tlen = sizeof(struct property) + len + 18;
 977
 978	prop = kzalloc(tlen, GFP_KERNEL);
 979	if (prop == NULL)
 980		return NULL;
 981	hdr = (struct smu_sdbp_header *)(prop + 1);
 982	prop->name = ((char *)prop) + tlen - 18;
 983	sprintf(prop->name, "sdb-partition-%02x", id);
 984	prop->length = len;
 985	prop->value = hdr;
 986	prop->next = NULL;
 987
 988	/* Read the datablock */
 989	if (smu_read_datablock((u8 *)hdr, addr, len)) {
 990		printk(KERN_DEBUG "SMU: datablock read failed while reading "
 991		       "partition %02x !\n", id);
 992		goto failure;
 993	}
 994
 995	/* Got it, check a few things and create the property */
 996	if (hdr->id != id) {
 997		printk(KERN_DEBUG "SMU: Reading partition %02x and got "
 998		       "%02x !\n", id, hdr->id);
 999		goto failure;
1000	}
1001	if (prom_add_property(smu->of_node, prop)) {
1002		printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1003		       "property !\n", id);
1004		goto failure;
1005	}
1006
1007	return hdr;
1008 failure:
1009	kfree(prop);
1010	return NULL;
1011}
1012
1013/* Note: Only allowed to return error code in pointers (using ERR_PTR)
1014 * when interruptible is 1
1015 */
1016const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1017		unsigned int *size, int interruptible)
1018{
1019	char pname[32];
1020	const struct smu_sdbp_header *part;
1021
1022	if (!smu)
1023		return NULL;
1024
1025	sprintf(pname, "sdb-partition-%02x", id);
1026
1027	DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1028
1029	if (interruptible) {
1030		int rc;
1031		rc = mutex_lock_interruptible(&smu_part_access);
1032		if (rc)
1033			return ERR_PTR(rc);
1034	} else
1035		mutex_lock(&smu_part_access);
1036
1037	part = of_get_property(smu->of_node, pname, size);
1038	if (part == NULL) {
1039		DPRINTK("trying to extract from SMU ...\n");
1040		part = smu_create_sdb_partition(id);
1041		if (part != NULL && size)
1042			*size = part->len << 2;
1043	}
1044	mutex_unlock(&smu_part_access);
1045	return part;
1046}
1047
1048const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1049{
1050	return __smu_get_sdb_partition(id, size, 0);
1051}
1052EXPORT_SYMBOL(smu_get_sdb_partition);
1053
1054
1055/*
1056 * Userland driver interface
1057 */
1058
1059
1060static LIST_HEAD(smu_clist);
1061static DEFINE_SPINLOCK(smu_clist_lock);
1062
1063enum smu_file_mode {
1064	smu_file_commands,
1065	smu_file_events,
1066	smu_file_closing
1067};
1068
1069struct smu_private
1070{
1071	struct list_head	list;
1072	enum smu_file_mode	mode;
1073	int			busy;
1074	struct smu_cmd		cmd;
1075	spinlock_t		lock;
1076	wait_queue_head_t	wait;
1077	u8			buffer[SMU_MAX_DATA];
1078};
1079
1080
1081static int smu_open(struct inode *inode, struct file *file)
1082{
1083	struct smu_private *pp;
1084	unsigned long flags;
1085
1086	pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1087	if (pp == 0)
1088		return -ENOMEM;
1089	spin_lock_init(&pp->lock);
1090	pp->mode = smu_file_commands;
1091	init_waitqueue_head(&pp->wait);
1092
1093	mutex_lock(&smu_mutex);
1094	spin_lock_irqsave(&smu_clist_lock, flags);
1095	list_add(&pp->list, &smu_clist);
1096	spin_unlock_irqrestore(&smu_clist_lock, flags);
1097	file->private_data = pp;
1098	mutex_unlock(&smu_mutex);
1099
1100	return 0;
1101}
1102
1103
1104static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1105{
1106	struct smu_private *pp = misc;
1107
1108	wake_up_all(&pp->wait);
1109}
1110
1111
1112static ssize_t smu_write(struct file *file, const char __user *buf,
1113			 size_t count, loff_t *ppos)
1114{
1115	struct smu_private *pp = file->private_data;
1116	unsigned long flags;
1117	struct smu_user_cmd_hdr hdr;
1118	int rc = 0;
1119
1120	if (pp->busy)
1121		return -EBUSY;
1122	else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1123		return -EFAULT;
1124	else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1125		pp->mode = smu_file_events;
1126		return 0;
1127	} else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1128		const struct smu_sdbp_header *part;
1129		part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1130		if (part == NULL)
1131			return -EINVAL;
1132		else if (IS_ERR(part))
1133			return PTR_ERR(part);
1134		return 0;
1135	} else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1136		return -EINVAL;
1137	else if (pp->mode != smu_file_commands)
1138		return -EBADFD;
1139	else if (hdr.data_len > SMU_MAX_DATA)
1140		return -EINVAL;
1141
1142	spin_lock_irqsave(&pp->lock, flags);
1143	if (pp->busy) {
1144		spin_unlock_irqrestore(&pp->lock, flags);
1145		return -EBUSY;
1146	}
1147	pp->busy = 1;
1148	pp->cmd.status = 1;
1149	spin_unlock_irqrestore(&pp->lock, flags);
1150
1151	if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1152		pp->busy = 0;
1153		return -EFAULT;
1154	}
1155
1156	pp->cmd.cmd = hdr.cmd;
1157	pp->cmd.data_len = hdr.data_len;
1158	pp->cmd.reply_len = SMU_MAX_DATA;
1159	pp->cmd.data_buf = pp->buffer;
1160	pp->cmd.reply_buf = pp->buffer;
1161	pp->cmd.done = smu_user_cmd_done;
1162	pp->cmd.misc = pp;
1163	rc = smu_queue_cmd(&pp->cmd);
1164	if (rc < 0)
1165		return rc;
1166	return count;
1167}
1168
1169
1170static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1171				char __user *buf, size_t count)
1172{
1173	DECLARE_WAITQUEUE(wait, current);
1174	struct smu_user_reply_hdr hdr;
1175	unsigned long flags;
1176	int size, rc = 0;
1177
1178	if (!pp->busy)
1179		return 0;
1180	if (count < sizeof(struct smu_user_reply_hdr))
1181		return -EOVERFLOW;
1182	spin_lock_irqsave(&pp->lock, flags);
1183	if (pp->cmd.status == 1) {
1184		if (file->f_flags & O_NONBLOCK) {
1185			spin_unlock_irqrestore(&pp->lock, flags);
1186			return -EAGAIN;
1187		}
1188		add_wait_queue(&pp->wait, &wait);
1189		for (;;) {
1190			set_current_state(TASK_INTERRUPTIBLE);
1191			rc = 0;
1192			if (pp->cmd.status != 1)
1193				break;
1194			rc = -ERESTARTSYS;
1195			if (signal_pending(current))
1196				break;
1197			spin_unlock_irqrestore(&pp->lock, flags);
1198			schedule();
1199			spin_lock_irqsave(&pp->lock, flags);
1200		}
1201		set_current_state(TASK_RUNNING);
1202		remove_wait_queue(&pp->wait, &wait);
1203	}
1204	spin_unlock_irqrestore(&pp->lock, flags);
1205	if (rc)
1206		return rc;
1207	if (pp->cmd.status != 0)
1208		pp->cmd.reply_len = 0;
1209	size = sizeof(hdr) + pp->cmd.reply_len;
1210	if (count < size)
1211		size = count;
1212	rc = size;
1213	hdr.status = pp->cmd.status;
1214	hdr.reply_len = pp->cmd.reply_len;
1215	if (copy_to_user(buf, &hdr, sizeof(hdr)))
1216		return -EFAULT;
1217	size -= sizeof(hdr);
1218	if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1219		return -EFAULT;
1220	pp->busy = 0;
1221
1222	return rc;
1223}
1224
1225
1226static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1227			       char __user *buf, size_t count)
1228{
1229	/* Not implemented */
1230	msleep_interruptible(1000);
1231	return 0;
1232}
1233
1234
1235static ssize_t smu_read(struct file *file, char __user *buf,
1236			size_t count, loff_t *ppos)
1237{
1238	struct smu_private *pp = file->private_data;
1239
1240	if (pp->mode == smu_file_commands)
1241		return smu_read_command(file, pp, buf, count);
1242	if (pp->mode == smu_file_events)
1243		return smu_read_events(file, pp, buf, count);
1244
1245	return -EBADFD;
1246}
1247
1248static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1249{
1250	struct smu_private *pp = file->private_data;
1251	unsigned int mask = 0;
1252	unsigned long flags;
1253
1254	if (pp == 0)
1255		return 0;
1256
1257	if (pp->mode == smu_file_commands) {
1258		poll_wait(file, &pp->wait, wait);
1259
1260		spin_lock_irqsave(&pp->lock, flags);
1261		if (pp->busy && pp->cmd.status != 1)
1262			mask |= POLLIN;
1263		spin_unlock_irqrestore(&pp->lock, flags);
1264	} if (pp->mode == smu_file_events) {
1265		/* Not yet implemented */
1266	}
1267	return mask;
1268}
1269
1270static int smu_release(struct inode *inode, struct file *file)
1271{
1272	struct smu_private *pp = file->private_data;
1273	unsigned long flags;
1274	unsigned int busy;
1275
1276	if (pp == 0)
1277		return 0;
1278
1279	file->private_data = NULL;
1280
1281	/* Mark file as closing to avoid races with new request */
1282	spin_lock_irqsave(&pp->lock, flags);
1283	pp->mode = smu_file_closing;
1284	busy = pp->busy;
1285
1286	/* Wait for any pending request to complete */
1287	if (busy && pp->cmd.status == 1) {
1288		DECLARE_WAITQUEUE(wait, current);
1289
1290		add_wait_queue(&pp->wait, &wait);
1291		for (;;) {
1292			set_current_state(TASK_UNINTERRUPTIBLE);
1293			if (pp->cmd.status != 1)
1294				break;
1295			spin_unlock_irqrestore(&pp->lock, flags);
1296			schedule();
1297			spin_lock_irqsave(&pp->lock, flags);
1298		}
1299		set_current_state(TASK_RUNNING);
1300		remove_wait_queue(&pp->wait, &wait);
1301	}
1302	spin_unlock_irqrestore(&pp->lock, flags);
1303
1304	spin_lock_irqsave(&smu_clist_lock, flags);
1305	list_del(&pp->list);
1306	spin_unlock_irqrestore(&smu_clist_lock, flags);
1307	kfree(pp);
1308
1309	return 0;
1310}
1311
1312
1313static const struct file_operations smu_device_fops = {
1314	.llseek		= no_llseek,
1315	.read		= smu_read,
1316	.write		= smu_write,
1317	.poll		= smu_fpoll,
1318	.open		= smu_open,
1319	.release	= smu_release,
1320};
1321
1322static struct miscdevice pmu_device = {
1323	MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1324};
1325
1326static int smu_device_init(void)
1327{
1328	if (!smu)
1329		return -ENODEV;
1330	if (misc_register(&pmu_device) < 0)
1331		printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1332	return 0;
1333}
1334device_initcall(smu_device_init);