rack-meter.c revision a419aef8b858a2bdb98df60336063d28df4b272f
1/* 2 * RackMac vu-meter driver 3 * 4 * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp. 5 * <benh@kernel.crashing.org> 6 * 7 * Released under the term of the GNU GPL v2. 8 * 9 * Support the CPU-meter LEDs of the Xserve G5 10 * 11 * TODO: Implement PWM to do variable intensity and provide userland 12 * interface for fun. Also, the CPU-meter could be made nicer by being 13 * a bit less "immediate" but giving instead a more average load over 14 * time. Patches welcome :-) 15 * 16 */ 17#undef DEBUG 18 19#include <linux/types.h> 20#include <linux/kernel.h> 21#include <linux/device.h> 22#include <linux/interrupt.h> 23#include <linux/module.h> 24#include <linux/pci.h> 25#include <linux/dma-mapping.h> 26#include <linux/kernel_stat.h> 27 28#include <asm/io.h> 29#include <asm/prom.h> 30#include <asm/machdep.h> 31#include <asm/pmac_feature.h> 32#include <asm/dbdma.h> 33#include <asm/macio.h> 34#include <asm/keylargo.h> 35 36/* Number of samples in a sample buffer */ 37#define SAMPLE_COUNT 256 38 39/* CPU meter sampling rate in ms */ 40#define CPU_SAMPLING_RATE 250 41 42struct rackmeter_dma { 43 struct dbdma_cmd cmd[4] ____cacheline_aligned; 44 u32 mark ____cacheline_aligned; 45 u32 buf1[SAMPLE_COUNT] ____cacheline_aligned; 46 u32 buf2[SAMPLE_COUNT] ____cacheline_aligned; 47} ____cacheline_aligned; 48 49struct rackmeter_cpu { 50 struct delayed_work sniffer; 51 struct rackmeter *rm; 52 cputime64_t prev_wall; 53 cputime64_t prev_idle; 54 int zero; 55} ____cacheline_aligned; 56 57struct rackmeter { 58 struct macio_dev *mdev; 59 unsigned int irq; 60 struct device_node *i2s; 61 u8 *ubuf; 62 struct dbdma_regs __iomem *dma_regs; 63 void __iomem *i2s_regs; 64 dma_addr_t dma_buf_p; 65 struct rackmeter_dma *dma_buf_v; 66 int stale_irq; 67 struct rackmeter_cpu cpu[2]; 68 int paused; 69 struct mutex sem; 70}; 71 72/* To be set as a tunable */ 73static int rackmeter_ignore_nice; 74 75/* This GPIO is whacked by the OS X driver when initializing */ 76#define RACKMETER_MAGIC_GPIO 0x78 77 78/* This is copied from cpufreq_ondemand, maybe we should put it in 79 * a common header somewhere 80 */ 81static inline cputime64_t get_cpu_idle_time(unsigned int cpu) 82{ 83 cputime64_t retval; 84 85 retval = cputime64_add(kstat_cpu(cpu).cpustat.idle, 86 kstat_cpu(cpu).cpustat.iowait); 87 88 if (rackmeter_ignore_nice) 89 retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice); 90 91 return retval; 92} 93 94static void rackmeter_setup_i2s(struct rackmeter *rm) 95{ 96 struct macio_chip *macio = rm->mdev->bus->chip; 97 98 /* First whack magic GPIO */ 99 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, RACKMETER_MAGIC_GPIO, 5); 100 101 102 /* Call feature code to enable the sound channel and the proper 103 * clock sources 104 */ 105 pmac_call_feature(PMAC_FTR_SOUND_CHIP_ENABLE, rm->i2s, 0, 1); 106 107 /* Power i2s and stop i2s clock. We whack MacIO FCRs directly for now. 108 * This is a bit racy, thus we should add new platform functions to 109 * handle that. snd-aoa needs that too 110 */ 111 MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_ENABLE); 112 MACIO_BIC(KEYLARGO_FCR1, KL1_I2S0_CLK_ENABLE_BIT); 113 (void)MACIO_IN32(KEYLARGO_FCR1); 114 udelay(10); 115 116 /* Then setup i2s. For now, we use the same magic value that 117 * the OS X driver seems to use. We might want to play around 118 * with the clock divisors later 119 */ 120 out_le32(rm->i2s_regs + 0x10, 0x01fa0000); 121 (void)in_le32(rm->i2s_regs + 0x10); 122 udelay(10); 123 124 /* Fully restart i2s*/ 125 MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_CELL_ENABLE | 126 KL1_I2S0_CLK_ENABLE_BIT); 127 (void)MACIO_IN32(KEYLARGO_FCR1); 128 udelay(10); 129} 130 131static void rackmeter_set_default_pattern(struct rackmeter *rm) 132{ 133 int i; 134 135 for (i = 0; i < 16; i++) { 136 if (i < 8) 137 rm->ubuf[i] = (i & 1) * 255; 138 else 139 rm->ubuf[i] = ((~i) & 1) * 255; 140 } 141} 142 143static void rackmeter_do_pause(struct rackmeter *rm, int pause) 144{ 145 struct rackmeter_dma *rdma = rm->dma_buf_v; 146 147 pr_debug("rackmeter: %s\n", pause ? "paused" : "started"); 148 149 rm->paused = pause; 150 if (pause) { 151 DBDMA_DO_STOP(rm->dma_regs); 152 return; 153 } 154 memset(rdma->buf1, 0, SAMPLE_COUNT & sizeof(u32)); 155 memset(rdma->buf2, 0, SAMPLE_COUNT & sizeof(u32)); 156 157 rm->dma_buf_v->mark = 0; 158 159 mb(); 160 out_le32(&rm->dma_regs->cmdptr_hi, 0); 161 out_le32(&rm->dma_regs->cmdptr, rm->dma_buf_p); 162 out_le32(&rm->dma_regs->control, (RUN << 16) | RUN); 163} 164 165static void rackmeter_setup_dbdma(struct rackmeter *rm) 166{ 167 struct rackmeter_dma *db = rm->dma_buf_v; 168 struct dbdma_cmd *cmd = db->cmd; 169 170 /* Make sure dbdma is reset */ 171 DBDMA_DO_RESET(rm->dma_regs); 172 173 pr_debug("rackmeter: mark offset=0x%zx\n", 174 offsetof(struct rackmeter_dma, mark)); 175 pr_debug("rackmeter: buf1 offset=0x%zx\n", 176 offsetof(struct rackmeter_dma, buf1)); 177 pr_debug("rackmeter: buf2 offset=0x%zx\n", 178 offsetof(struct rackmeter_dma, buf2)); 179 180 /* Prepare 4 dbdma commands for the 2 buffers */ 181 memset(cmd, 0, 4 * sizeof(struct dbdma_cmd)); 182 st_le16(&cmd->req_count, 4); 183 st_le16(&cmd->command, STORE_WORD | INTR_ALWAYS | KEY_SYSTEM); 184 st_le32(&cmd->phy_addr, rm->dma_buf_p + 185 offsetof(struct rackmeter_dma, mark)); 186 st_le32(&cmd->cmd_dep, 0x02000000); 187 cmd++; 188 189 st_le16(&cmd->req_count, SAMPLE_COUNT * 4); 190 st_le16(&cmd->command, OUTPUT_MORE); 191 st_le32(&cmd->phy_addr, rm->dma_buf_p + 192 offsetof(struct rackmeter_dma, buf1)); 193 cmd++; 194 195 st_le16(&cmd->req_count, 4); 196 st_le16(&cmd->command, STORE_WORD | INTR_ALWAYS | KEY_SYSTEM); 197 st_le32(&cmd->phy_addr, rm->dma_buf_p + 198 offsetof(struct rackmeter_dma, mark)); 199 st_le32(&cmd->cmd_dep, 0x01000000); 200 cmd++; 201 202 st_le16(&cmd->req_count, SAMPLE_COUNT * 4); 203 st_le16(&cmd->command, OUTPUT_MORE | BR_ALWAYS); 204 st_le32(&cmd->phy_addr, rm->dma_buf_p + 205 offsetof(struct rackmeter_dma, buf2)); 206 st_le32(&cmd->cmd_dep, rm->dma_buf_p); 207 208 rackmeter_do_pause(rm, 0); 209} 210 211static void rackmeter_do_timer(struct work_struct *work) 212{ 213 struct rackmeter_cpu *rcpu = 214 container_of(work, struct rackmeter_cpu, sniffer.work); 215 struct rackmeter *rm = rcpu->rm; 216 unsigned int cpu = smp_processor_id(); 217 cputime64_t cur_jiffies, total_idle_ticks; 218 unsigned int total_ticks, idle_ticks; 219 int i, offset, load, cumm, pause; 220 221 cur_jiffies = jiffies64_to_cputime64(get_jiffies_64()); 222 total_ticks = (unsigned int)cputime64_sub(cur_jiffies, 223 rcpu->prev_wall); 224 rcpu->prev_wall = cur_jiffies; 225 226 total_idle_ticks = get_cpu_idle_time(cpu); 227 idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks, 228 rcpu->prev_idle); 229 rcpu->prev_idle = total_idle_ticks; 230 231 /* We do a very dumb calculation to update the LEDs for now, 232 * we'll do better once we have actual PWM implemented 233 */ 234 load = (9 * (total_ticks - idle_ticks)) / total_ticks; 235 236 offset = cpu << 3; 237 cumm = 0; 238 for (i = 0; i < 8; i++) { 239 u8 ub = (load > i) ? 0xff : 0; 240 rm->ubuf[i + offset] = ub; 241 cumm |= ub; 242 } 243 rcpu->zero = (cumm == 0); 244 245 /* Now check if LEDs are all 0, we can stop DMA */ 246 pause = (rm->cpu[0].zero && rm->cpu[1].zero); 247 if (pause != rm->paused) { 248 mutex_lock(&rm->sem); 249 pause = (rm->cpu[0].zero && rm->cpu[1].zero); 250 rackmeter_do_pause(rm, pause); 251 mutex_unlock(&rm->sem); 252 } 253 schedule_delayed_work_on(cpu, &rcpu->sniffer, 254 msecs_to_jiffies(CPU_SAMPLING_RATE)); 255} 256 257static void __devinit rackmeter_init_cpu_sniffer(struct rackmeter *rm) 258{ 259 unsigned int cpu; 260 261 /* This driver works only with 1 or 2 CPUs numbered 0 and 1, 262 * but that's really all we have on Apple Xserve. It doesn't 263 * play very nice with CPU hotplug neither but we don't do that 264 * on those machines yet 265 */ 266 267 rm->cpu[0].rm = rm; 268 INIT_DELAYED_WORK(&rm->cpu[0].sniffer, rackmeter_do_timer); 269 rm->cpu[1].rm = rm; 270 INIT_DELAYED_WORK(&rm->cpu[1].sniffer, rackmeter_do_timer); 271 272 for_each_online_cpu(cpu) { 273 struct rackmeter_cpu *rcpu; 274 275 if (cpu > 1) 276 continue; 277 rcpu = &rm->cpu[cpu]; 278 rcpu->prev_idle = get_cpu_idle_time(cpu); 279 rcpu->prev_wall = jiffies64_to_cputime64(get_jiffies_64()); 280 schedule_delayed_work_on(cpu, &rm->cpu[cpu].sniffer, 281 msecs_to_jiffies(CPU_SAMPLING_RATE)); 282 } 283} 284 285static void __devexit rackmeter_stop_cpu_sniffer(struct rackmeter *rm) 286{ 287 cancel_rearming_delayed_work(&rm->cpu[0].sniffer); 288 cancel_rearming_delayed_work(&rm->cpu[1].sniffer); 289} 290 291static int __devinit rackmeter_setup(struct rackmeter *rm) 292{ 293 pr_debug("rackmeter: setting up i2s..\n"); 294 rackmeter_setup_i2s(rm); 295 296 pr_debug("rackmeter: setting up default pattern..\n"); 297 rackmeter_set_default_pattern(rm); 298 299 pr_debug("rackmeter: setting up dbdma..\n"); 300 rackmeter_setup_dbdma(rm); 301 302 pr_debug("rackmeter: start CPU measurements..\n"); 303 rackmeter_init_cpu_sniffer(rm); 304 305 printk(KERN_INFO "RackMeter initialized\n"); 306 307 return 0; 308} 309 310/* XXX FIXME: No PWM yet, this is 0/1 */ 311static u32 rackmeter_calc_sample(struct rackmeter *rm, unsigned int index) 312{ 313 int led; 314 u32 sample = 0; 315 316 for (led = 0; led < 16; led++) { 317 sample >>= 1; 318 sample |= ((rm->ubuf[led] >= 0x80) << 15); 319 } 320 return (sample << 17) | (sample >> 15); 321} 322 323static irqreturn_t rackmeter_irq(int irq, void *arg) 324{ 325 struct rackmeter *rm = arg; 326 struct rackmeter_dma *db = rm->dma_buf_v; 327 unsigned int mark, i; 328 u32 *buf; 329 330 /* Flush PCI buffers with an MMIO read. Maybe we could actually 331 * check the status one day ... in case things go wrong, though 332 * this never happened to me 333 */ 334 (void)in_le32(&rm->dma_regs->status); 335 336 /* Make sure the CPU gets us in order */ 337 rmb(); 338 339 /* Read mark */ 340 mark = db->mark; 341 if (mark != 1 && mark != 2) { 342 printk(KERN_WARNING "rackmeter: Incorrect DMA mark 0x%08x\n", 343 mark); 344 /* We allow for 3 errors like that (stale DBDMA irqs) */ 345 if (++rm->stale_irq > 3) { 346 printk(KERN_ERR "rackmeter: Too many errors," 347 " stopping DMA\n"); 348 DBDMA_DO_RESET(rm->dma_regs); 349 } 350 return IRQ_HANDLED; 351 } 352 353 /* Next buffer we need to fill is mark value */ 354 buf = mark == 1 ? db->buf1 : db->buf2; 355 356 /* Fill it now. This routine converts the 8 bits depth sample array 357 * into the PWM bitmap for each LED. 358 */ 359 for (i = 0; i < SAMPLE_COUNT; i++) 360 buf[i] = rackmeter_calc_sample(rm, i); 361 362 363 return IRQ_HANDLED; 364} 365 366static int __devinit rackmeter_probe(struct macio_dev* mdev, 367 const struct of_device_id *match) 368{ 369 struct device_node *i2s = NULL, *np = NULL; 370 struct rackmeter *rm = NULL; 371 struct resource ri2s, rdma; 372 int rc = -ENODEV; 373 374 pr_debug("rackmeter_probe()\n"); 375 376 /* Get i2s-a node */ 377 while ((i2s = of_get_next_child(mdev->ofdev.node, i2s)) != NULL) 378 if (strcmp(i2s->name, "i2s-a") == 0) 379 break; 380 if (i2s == NULL) { 381 pr_debug(" i2s-a child not found\n"); 382 goto bail; 383 } 384 /* Get lightshow or virtual sound */ 385 while ((np = of_get_next_child(i2s, np)) != NULL) { 386 if (strcmp(np->name, "lightshow") == 0) 387 break; 388 if ((strcmp(np->name, "sound") == 0) && 389 of_get_property(np, "virtual", NULL) != NULL) 390 break; 391 } 392 if (np == NULL) { 393 pr_debug(" lightshow or sound+virtual child not found\n"); 394 goto bail; 395 } 396 397 /* Create and initialize our instance data */ 398 rm = kzalloc(sizeof(struct rackmeter), GFP_KERNEL); 399 if (rm == NULL) { 400 printk(KERN_ERR "rackmeter: failed to allocate memory !\n"); 401 rc = -ENOMEM; 402 goto bail_release; 403 } 404 rm->mdev = mdev; 405 rm->i2s = i2s; 406 mutex_init(&rm->sem); 407 dev_set_drvdata(&mdev->ofdev.dev, rm); 408 /* Check resources availability. We need at least resource 0 and 1 */ 409#if 0 /* Use that when i2s-a is finally an mdev per-se */ 410 if (macio_resource_count(mdev) < 2 || macio_irq_count(mdev) < 2) { 411 printk(KERN_ERR 412 "rackmeter: found match but lacks resources: %s" 413 " (%d resources, %d interrupts)\n", 414 mdev->ofdev.node->full_name); 415 rc = -ENXIO; 416 goto bail_free; 417 } 418 if (macio_request_resources(mdev, "rackmeter")) { 419 printk(KERN_ERR 420 "rackmeter: failed to request resources: %s\n", 421 mdev->ofdev.node->full_name); 422 rc = -EBUSY; 423 goto bail_free; 424 } 425 rm->irq = macio_irq(mdev, 1); 426#else 427 rm->irq = irq_of_parse_and_map(i2s, 1); 428 if (rm->irq == NO_IRQ || 429 of_address_to_resource(i2s, 0, &ri2s) || 430 of_address_to_resource(i2s, 1, &rdma)) { 431 printk(KERN_ERR 432 "rackmeter: found match but lacks resources: %s", 433 mdev->ofdev.node->full_name); 434 rc = -ENXIO; 435 goto bail_free; 436 } 437#endif 438 439 pr_debug(" i2s @0x%08x\n", (unsigned int)ri2s.start); 440 pr_debug(" dma @0x%08x\n", (unsigned int)rdma.start); 441 pr_debug(" irq %d\n", rm->irq); 442 443 rm->ubuf = (u8 *)__get_free_page(GFP_KERNEL); 444 if (rm->ubuf == NULL) { 445 printk(KERN_ERR 446 "rackmeter: failed to allocate samples page !\n"); 447 rc = -ENOMEM; 448 goto bail_release; 449 } 450 451 rm->dma_buf_v = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev, 452 sizeof(struct rackmeter_dma), 453 &rm->dma_buf_p, GFP_KERNEL); 454 if (rm->dma_buf_v == NULL) { 455 printk(KERN_ERR 456 "rackmeter: failed to allocate dma buffer !\n"); 457 rc = -ENOMEM; 458 goto bail_free_samples; 459 } 460#if 0 461 rm->i2s_regs = ioremap(macio_resource_start(mdev, 0), 0x1000); 462#else 463 rm->i2s_regs = ioremap(ri2s.start, 0x1000); 464#endif 465 if (rm->i2s_regs == NULL) { 466 printk(KERN_ERR 467 "rackmeter: failed to map i2s registers !\n"); 468 rc = -ENXIO; 469 goto bail_free_dma; 470 } 471#if 0 472 rm->dma_regs = ioremap(macio_resource_start(mdev, 1), 0x100); 473#else 474 rm->dma_regs = ioremap(rdma.start, 0x100); 475#endif 476 if (rm->dma_regs == NULL) { 477 printk(KERN_ERR 478 "rackmeter: failed to map dma registers !\n"); 479 rc = -ENXIO; 480 goto bail_unmap_i2s; 481 } 482 483 rc = rackmeter_setup(rm); 484 if (rc) { 485 printk(KERN_ERR 486 "rackmeter: failed to initialize !\n"); 487 rc = -ENXIO; 488 goto bail_unmap_dma; 489 } 490 491 rc = request_irq(rm->irq, rackmeter_irq, 0, "rackmeter", rm); 492 if (rc != 0) { 493 printk(KERN_ERR 494 "rackmeter: failed to request interrupt !\n"); 495 goto bail_stop_dma; 496 } 497 of_node_put(np); 498 return 0; 499 500 bail_stop_dma: 501 DBDMA_DO_RESET(rm->dma_regs); 502 bail_unmap_dma: 503 iounmap(rm->dma_regs); 504 bail_unmap_i2s: 505 iounmap(rm->i2s_regs); 506 bail_free_dma: 507 dma_free_coherent(&macio_get_pci_dev(mdev)->dev, 508 sizeof(struct rackmeter_dma), 509 rm->dma_buf_v, rm->dma_buf_p); 510 bail_free_samples: 511 free_page((unsigned long)rm->ubuf); 512 bail_release: 513#if 0 514 macio_release_resources(mdev); 515#endif 516 bail_free: 517 kfree(rm); 518 bail: 519 of_node_put(i2s); 520 of_node_put(np); 521 dev_set_drvdata(&mdev->ofdev.dev, NULL); 522 return rc; 523} 524 525static int __devexit rackmeter_remove(struct macio_dev* mdev) 526{ 527 struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev); 528 529 /* Stop CPU sniffer timer & work queues */ 530 rackmeter_stop_cpu_sniffer(rm); 531 532 /* Clear reference to private data */ 533 dev_set_drvdata(&mdev->ofdev.dev, NULL); 534 535 /* Stop/reset dbdma */ 536 DBDMA_DO_RESET(rm->dma_regs); 537 538 /* Release the IRQ */ 539 free_irq(rm->irq, rm); 540 541 /* Unmap registers */ 542 iounmap(rm->dma_regs); 543 iounmap(rm->i2s_regs); 544 545 /* Free DMA */ 546 dma_free_coherent(&macio_get_pci_dev(mdev)->dev, 547 sizeof(struct rackmeter_dma), 548 rm->dma_buf_v, rm->dma_buf_p); 549 550 /* Free samples */ 551 free_page((unsigned long)rm->ubuf); 552 553#if 0 554 /* Release resources */ 555 macio_release_resources(mdev); 556#endif 557 558 /* Get rid of me */ 559 kfree(rm); 560 561 return 0; 562} 563 564static int rackmeter_shutdown(struct macio_dev* mdev) 565{ 566 struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev); 567 568 if (rm == NULL) 569 return -ENODEV; 570 571 /* Stop CPU sniffer timer & work queues */ 572 rackmeter_stop_cpu_sniffer(rm); 573 574 /* Stop/reset dbdma */ 575 DBDMA_DO_RESET(rm->dma_regs); 576 577 return 0; 578} 579 580static struct of_device_id rackmeter_match[] = { 581 { .name = "i2s" }, 582 { } 583}; 584 585static struct macio_driver rackmeter_driver = { 586 .name = "rackmeter", 587 .owner = THIS_MODULE, 588 .match_table = rackmeter_match, 589 .probe = rackmeter_probe, 590 .remove = __devexit_p(rackmeter_remove), 591 .shutdown = rackmeter_shutdown, 592}; 593 594 595static int __init rackmeter_init(void) 596{ 597 pr_debug("rackmeter_init()\n"); 598 599 return macio_register_driver(&rackmeter_driver); 600} 601 602static void __exit rackmeter_exit(void) 603{ 604 pr_debug("rackmeter_exit()\n"); 605 606 macio_unregister_driver(&rackmeter_driver); 607} 608 609module_init(rackmeter_init); 610module_exit(rackmeter_exit); 611 612 613MODULE_LICENSE("GPL"); 614MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 615MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel"); 616