rack-meter.c revision 3e00a5aec3d6af687e37f4e7482f5c7ecdcabd0b
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/dbdma.h> 34#include <asm/macio.h> 35#include <asm/keylargo.h> 36 37/* Number of samples in a sample buffer */ 38#define SAMPLE_COUNT 256 39 40/* CPU meter sampling rate in ms */ 41#define CPU_SAMPLING_RATE 250 42 43struct rackmeter_dma { 44 struct dbdma_cmd cmd[4] ____cacheline_aligned; 45 u32 mark ____cacheline_aligned; 46 u32 buf1[SAMPLE_COUNT] ____cacheline_aligned; 47 u32 buf2[SAMPLE_COUNT] ____cacheline_aligned; 48} ____cacheline_aligned; 49 50struct rackmeter_cpu { 51 struct work_struct sniffer; 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%lx\n", 174 offsetof(struct rackmeter_dma, mark)); 175 pr_debug("rackmeter: buf1 offset=0x%lx\n", 176 offsetof(struct rackmeter_dma, buf1)); 177 pr_debug("rackmeter: buf2 offset=0x%lx\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(void *data) 212{ 213 struct rackmeter *rm = data; 214 unsigned int cpu = smp_processor_id(); 215 struct rackmeter_cpu *rcpu = &rm->cpu[cpu]; 216 cputime64_t cur_jiffies, total_idle_ticks; 217 unsigned int total_ticks, idle_ticks; 218 int i, offset, load, cumm, pause; 219 220 cur_jiffies = jiffies64_to_cputime64(get_jiffies_64()); 221 total_ticks = (unsigned int)cputime64_sub(cur_jiffies, 222 rcpu->prev_wall); 223 rcpu->prev_wall = cur_jiffies; 224 225 total_idle_ticks = get_cpu_idle_time(cpu); 226 idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks, 227 rcpu->prev_idle); 228 rcpu->prev_idle = total_idle_ticks; 229 230 /* We do a very dumb calculation to update the LEDs for now, 231 * we'll do better once we have actual PWM implemented 232 */ 233 load = (9 * (total_ticks - idle_ticks)) / total_ticks; 234 235 offset = cpu << 3; 236 cumm = 0; 237 for (i = 0; i < 8; i++) { 238 u8 ub = (load > i) ? 0xff : 0; 239 rm->ubuf[i + offset] = ub; 240 cumm |= ub; 241 } 242 rcpu->zero = (cumm == 0); 243 244 /* Now check if LEDs are all 0, we can stop DMA */ 245 pause = (rm->cpu[0].zero && rm->cpu[1].zero); 246 if (pause != rm->paused) { 247 mutex_lock(&rm->sem); 248 pause = (rm->cpu[0].zero && rm->cpu[1].zero); 249 rackmeter_do_pause(rm, pause); 250 mutex_unlock(&rm->sem); 251 } 252 schedule_delayed_work_on(cpu, &rcpu->sniffer, 253 msecs_to_jiffies(CPU_SAMPLING_RATE)); 254} 255 256static void __devinit rackmeter_init_cpu_sniffer(struct rackmeter *rm) 257{ 258 unsigned int cpu; 259 260 /* This driver works only with 1 or 2 CPUs numbered 0 and 1, 261 * but that's really all we have on Apple Xserve. It doesn't 262 * play very nice with CPU hotplug neither but we don't do that 263 * on those machines yet 264 */ 265 266 INIT_WORK(&rm->cpu[0].sniffer, rackmeter_do_timer, rm); 267 INIT_WORK(&rm->cpu[1].sniffer, rackmeter_do_timer, rm); 268 269 for_each_online_cpu(cpu) { 270 struct rackmeter_cpu *rcpu; 271 272 if (cpu > 1) 273 continue; 274 rcpu = &rm->cpu[cpu];; 275 rcpu->prev_idle = get_cpu_idle_time(cpu); 276 rcpu->prev_wall = jiffies64_to_cputime64(get_jiffies_64()); 277 schedule_delayed_work_on(cpu, &rm->cpu[cpu].sniffer, 278 msecs_to_jiffies(CPU_SAMPLING_RATE)); 279 } 280} 281 282static void __devexit rackmeter_stop_cpu_sniffer(struct rackmeter *rm) 283{ 284 cancel_rearming_delayed_work(&rm->cpu[0].sniffer); 285 cancel_rearming_delayed_work(&rm->cpu[1].sniffer); 286} 287 288static int rackmeter_setup(struct rackmeter *rm) 289{ 290 pr_debug("rackmeter: setting up i2s..\n"); 291 rackmeter_setup_i2s(rm); 292 293 pr_debug("rackmeter: setting up default pattern..\n"); 294 rackmeter_set_default_pattern(rm); 295 296 pr_debug("rackmeter: setting up dbdma..\n"); 297 rackmeter_setup_dbdma(rm); 298 299 pr_debug("rackmeter: start CPU measurements..\n"); 300 rackmeter_init_cpu_sniffer(rm); 301 302 printk(KERN_INFO "RackMeter initialized\n"); 303 304 return 0; 305} 306 307/* XXX FIXME: No PWM yet, this is 0/1 */ 308static u32 rackmeter_calc_sample(struct rackmeter *rm, unsigned int index) 309{ 310 int led; 311 u32 sample = 0; 312 313 for (led = 0; led < 16; led++) { 314 sample >>= 1; 315 sample |= ((rm->ubuf[led] >= 0x80) << 15); 316 } 317 return (sample << 17) | (sample >> 15); 318} 319 320static irqreturn_t rackmeter_irq(int irq, void *arg) 321{ 322 struct rackmeter *rm = arg; 323 struct rackmeter_dma *db = rm->dma_buf_v; 324 unsigned int mark, i; 325 u32 *buf; 326 327 /* Flush PCI buffers with an MMIO read. Maybe we could actually 328 * check the status one day ... in case things go wrong, though 329 * this never happened to me 330 */ 331 (void)in_le32(&rm->dma_regs->status); 332 333 /* Make sure the CPU gets us in order */ 334 rmb(); 335 336 /* Read mark */ 337 mark = db->mark; 338 if (mark != 1 && mark != 2) { 339 printk(KERN_WARNING "rackmeter: Incorrect DMA mark 0x%08x\n", 340 mark); 341 /* We allow for 3 errors like that (stale DBDMA irqs) */ 342 if (++rm->stale_irq > 3) { 343 printk(KERN_ERR "rackmeter: Too many errors," 344 " stopping DMA\n"); 345 DBDMA_DO_RESET(rm->dma_regs); 346 } 347 return IRQ_HANDLED; 348 } 349 350 /* Next buffer we need to fill is mark value */ 351 buf = mark == 1 ? db->buf1 : db->buf2; 352 353 /* Fill it now. This routine converts the 8 bits depth sample array 354 * into the PWM bitmap for each LED. 355 */ 356 for (i = 0; i < SAMPLE_COUNT; i++) 357 buf[i] = rackmeter_calc_sample(rm, i); 358 359 360 return IRQ_HANDLED; 361} 362 363static int __devinit rackmeter_probe(struct macio_dev* mdev, 364 const struct of_device_id *match) 365{ 366 struct device_node *i2s = NULL, *np = NULL; 367 struct rackmeter *rm = NULL; 368 struct resource ri2s, rdma; 369 int rc = -ENODEV; 370 371 pr_debug("rackmeter_probe()\n"); 372 373 /* Get i2s-a node */ 374 while ((i2s = of_get_next_child(mdev->ofdev.node, i2s)) != NULL) 375 if (strcmp(i2s->name, "i2s-a") == 0) 376 break; 377 if (i2s == NULL) { 378 pr_debug(" i2s-a child not found\n"); 379 goto bail; 380 } 381 /* Get lightshow or virtual sound */ 382 while ((np = of_get_next_child(i2s, np)) != NULL) { 383 if (strcmp(np->name, "lightshow") == 0) 384 break; 385 if ((strcmp(np->name, "sound") == 0) && 386 get_property(np, "virtual", NULL) != NULL) 387 break; 388 } 389 if (np == NULL) { 390 pr_debug(" lightshow or sound+virtual child not found\n"); 391 goto bail; 392 } 393 394 /* Create and initialize our instance data */ 395 rm = kzalloc(sizeof(struct rackmeter), GFP_KERNEL); 396 if (rm == NULL) { 397 printk(KERN_ERR "rackmeter: failed to allocate memory !\n"); 398 rc = -ENOMEM; 399 goto bail_release; 400 } 401 rm->mdev = mdev; 402 rm->i2s = i2s; 403 mutex_init(&rm->sem); 404 dev_set_drvdata(&mdev->ofdev.dev, rm); 405 /* Check resources availability. We need at least resource 0 and 1 */ 406#if 0 /* Use that when i2s-a is finally an mdev per-se */ 407 if (macio_resource_count(mdev) < 2 || macio_irq_count(mdev) < 2) { 408 printk(KERN_ERR 409 "rackmeter: found match but lacks resources: %s" 410 " (%d resources, %d interrupts)\n", 411 mdev->ofdev.node->full_name); 412 rc = -ENXIO; 413 goto bail_free; 414 } 415 if (macio_request_resources(mdev, "rackmeter")) { 416 printk(KERN_ERR 417 "rackmeter: failed to request resources: %s\n", 418 mdev->ofdev.node->full_name); 419 rc = -EBUSY; 420 goto bail_free; 421 } 422 rm->irq = macio_irq(mdev, 1); 423#else 424 rm->irq = irq_of_parse_and_map(i2s, 1); 425 if (rm->irq == NO_IRQ || 426 of_address_to_resource(i2s, 0, &ri2s) || 427 of_address_to_resource(i2s, 1, &rdma)) { 428 printk(KERN_ERR 429 "rackmeter: found match but lacks resources: %s", 430 mdev->ofdev.node->full_name); 431 rc = -ENXIO; 432 goto bail_free; 433 } 434#endif 435 436 pr_debug(" i2s @0x%08x\n", (unsigned int)ri2s.start); 437 pr_debug(" dma @0x%08x\n", (unsigned int)rdma.start); 438 pr_debug(" irq %d\n", rm->irq); 439 440 rm->ubuf = (u8 *)__get_free_page(GFP_KERNEL); 441 if (rm->ubuf == NULL) { 442 printk(KERN_ERR 443 "rackmeter: failed to allocate samples page !\n"); 444 rc = -ENOMEM; 445 goto bail_release; 446 } 447 448 rm->dma_buf_v = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev, 449 sizeof(struct rackmeter_dma), 450 &rm->dma_buf_p, GFP_KERNEL); 451 if (rm->dma_buf_v == NULL) { 452 printk(KERN_ERR 453 "rackmeter: failed to allocate dma buffer !\n"); 454 rc = -ENOMEM; 455 goto bail_free_samples; 456 } 457#if 0 458 rm->i2s_regs = ioremap(macio_resource_start(mdev, 0), 0x1000); 459#else 460 rm->i2s_regs = ioremap(ri2s.start, 0x1000); 461#endif 462 if (rm->i2s_regs == NULL) { 463 printk(KERN_ERR 464 "rackmeter: failed to map i2s registers !\n"); 465 rc = -ENXIO; 466 goto bail_free_dma; 467 } 468#if 0 469 rm->dma_regs = ioremap(macio_resource_start(mdev, 1), 0x100); 470#else 471 rm->dma_regs = ioremap(rdma.start, 0x100); 472#endif 473 if (rm->dma_regs == NULL) { 474 printk(KERN_ERR 475 "rackmeter: failed to map dma registers !\n"); 476 rc = -ENXIO; 477 goto bail_unmap_i2s; 478 } 479 480 rc = rackmeter_setup(rm); 481 if (rc) { 482 printk(KERN_ERR 483 "rackmeter: failed to initialize !\n"); 484 rc = -ENXIO; 485 goto bail_unmap_dma; 486 } 487 488 rc = request_irq(rm->irq, rackmeter_irq, 0, "rackmeter", rm); 489 if (rc != 0) { 490 printk(KERN_ERR 491 "rackmeter: failed to request interrupt !\n"); 492 goto bail_stop_dma; 493 } 494 of_node_put(np); 495 return 0; 496 497 bail_stop_dma: 498 DBDMA_DO_RESET(rm->dma_regs); 499 bail_unmap_dma: 500 iounmap(rm->dma_regs); 501 bail_unmap_i2s: 502 iounmap(rm->i2s_regs); 503 bail_free_dma: 504 dma_free_coherent(&macio_get_pci_dev(mdev)->dev, 505 sizeof(struct rackmeter_dma), 506 rm->dma_buf_v, rm->dma_buf_p); 507 bail_free_samples: 508 free_page((unsigned long)rm->ubuf); 509 bail_release: 510#if 0 511 macio_release_resources(mdev); 512#endif 513 bail_free: 514 kfree(rm); 515 bail: 516 of_node_put(i2s); 517 of_node_put(np); 518 dev_set_drvdata(&mdev->ofdev.dev, NULL); 519 return rc; 520} 521 522static int __devexit rackmeter_remove(struct macio_dev* mdev) 523{ 524 struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev); 525 526 /* Stop CPU sniffer timer & work queues */ 527 rackmeter_stop_cpu_sniffer(rm); 528 529 /* Clear reference to private data */ 530 dev_set_drvdata(&mdev->ofdev.dev, NULL); 531 532 /* Stop/reset dbdma */ 533 DBDMA_DO_RESET(rm->dma_regs); 534 535 /* Release the IRQ */ 536 free_irq(rm->irq, rm); 537 538 /* Unmap registers */ 539 iounmap(rm->dma_regs); 540 iounmap(rm->i2s_regs); 541 542 /* Free DMA */ 543 dma_free_coherent(&macio_get_pci_dev(mdev)->dev, 544 sizeof(struct rackmeter_dma), 545 rm->dma_buf_v, rm->dma_buf_p); 546 547 /* Free samples */ 548 free_page((unsigned long)rm->ubuf); 549 550#if 0 551 /* Release resources */ 552 macio_release_resources(mdev); 553#endif 554 555 /* Get rid of me */ 556 kfree(rm); 557 558 return 0; 559} 560 561static int rackmeter_shutdown(struct macio_dev* mdev) 562{ 563 struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev); 564 565 if (rm == NULL) 566 return -ENODEV; 567 568 /* Stop CPU sniffer timer & work queues */ 569 rackmeter_stop_cpu_sniffer(rm); 570 571 /* Stop/reset dbdma */ 572 DBDMA_DO_RESET(rm->dma_regs); 573 574 return 0; 575} 576 577static struct of_device_id rackmeter_match[] = { 578 { .name = "i2s" }, 579 { } 580}; 581 582static struct macio_driver rackmeter_drv = { 583 .name = "rackmeter", 584 .owner = THIS_MODULE, 585 .match_table = rackmeter_match, 586 .probe = rackmeter_probe, 587 .remove = rackmeter_remove, 588 .shutdown = rackmeter_shutdown, 589}; 590 591 592static int __init rackmeter_init(void) 593{ 594 pr_debug("rackmeter_init()\n"); 595 596 return macio_register_driver(&rackmeter_drv); 597} 598 599static void __exit rackmeter_exit(void) 600{ 601 pr_debug("rackmeter_exit()\n"); 602 603 macio_unregister_driver(&rackmeter_drv); 604} 605 606module_init(rackmeter_init); 607module_exit(rackmeter_exit); 608 609 610MODULE_LICENSE("GPL"); 611MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 612MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel"); 613