Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/macintosh/rack-meter.c

  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/slab.h>
 22 #include <linux/device.h>
 23 #include <linux/interrupt.h>
 24 #include <linux/module.h>
 25 #include <linux/pci.h>
 26 #include <linux/dma-mapping.h>
 27 #include <linux/kernel_stat.h>
 28 #include <linux/of_address.h>
 29 #include <linux/of_irq.h>
 30 
 31 #include <asm/io.h>
 32 #include <asm/prom.h>
 33 #include <asm/machdep.h>
 34 #include <asm/pmac_feature.h>
 35 #include <asm/dbdma.h>
 36 #include <asm/macio.h>
 37 #include <asm/keylargo.h>
 38 
 39 /* Number of samples in a sample buffer */
 40 #define SAMPLE_COUNT            256
 41 
 42 /* CPU meter sampling rate in ms */
 43 #define CPU_SAMPLING_RATE       250
 44 
 45 struct rackmeter_dma {
 46         struct dbdma_cmd        cmd[4]                  ____cacheline_aligned;
 47         u32                     mark                    ____cacheline_aligned;
 48         u32                     buf1[SAMPLE_COUNT]      ____cacheline_aligned;
 49         u32                     buf2[SAMPLE_COUNT]      ____cacheline_aligned;
 50 } ____cacheline_aligned;
 51 
 52 struct rackmeter_cpu {
 53         struct delayed_work     sniffer;
 54         struct rackmeter        *rm;
 55         cputime64_t             prev_wall;
 56         cputime64_t             prev_idle;
 57         int                     zero;
 58 } ____cacheline_aligned;
 59 
 60 struct rackmeter {
 61         struct macio_dev                *mdev;
 62         unsigned int                    irq;
 63         struct device_node              *i2s;
 64         u8                              *ubuf;
 65         struct dbdma_regs __iomem       *dma_regs;
 66         void __iomem                    *i2s_regs;
 67         dma_addr_t                      dma_buf_p;
 68         struct rackmeter_dma            *dma_buf_v;
 69         int                             stale_irq;
 70         struct rackmeter_cpu            cpu[2];
 71         int                             paused;
 72         struct mutex                    sem;
 73 };
 74 
 75 /* To be set as a tunable */
 76 static int rackmeter_ignore_nice;
 77 
 78 /* This GPIO is whacked by the OS X driver when initializing */
 79 #define RACKMETER_MAGIC_GPIO    0x78
 80 
 81 /* This is copied from cpufreq_ondemand, maybe we should put it in
 82  * a common header somewhere
 83  */
 84 static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
 85 {
 86         u64 retval;
 87 
 88         retval = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE] +
 89                  kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
 90 
 91         if (rackmeter_ignore_nice)
 92                 retval += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
 93 
 94         return retval;
 95 }
 96 
 97 static void rackmeter_setup_i2s(struct rackmeter *rm)
 98 {
 99         struct macio_chip *macio = rm->mdev->bus->chip;
100 
101         /* First whack magic GPIO */
102         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, RACKMETER_MAGIC_GPIO, 5);
103 
104 
105         /* Call feature code to enable the sound channel and the proper
106          * clock sources
107          */
108         pmac_call_feature(PMAC_FTR_SOUND_CHIP_ENABLE, rm->i2s, 0, 1);
109 
110         /* Power i2s and stop i2s clock. We whack MacIO FCRs directly for now.
111          * This is a bit racy, thus we should add new platform functions to
112          * handle that. snd-aoa needs that too
113          */
114         MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_ENABLE);
115         MACIO_BIC(KEYLARGO_FCR1, KL1_I2S0_CLK_ENABLE_BIT);
116         (void)MACIO_IN32(KEYLARGO_FCR1);
117         udelay(10);
118 
119         /* Then setup i2s. For now, we use the same magic value that
120          * the OS X driver seems to use. We might want to play around
121          * with the clock divisors later
122          */
123         out_le32(rm->i2s_regs + 0x10, 0x01fa0000);
124         (void)in_le32(rm->i2s_regs + 0x10);
125         udelay(10);
126 
127         /* Fully restart i2s*/
128         MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_CELL_ENABLE |
129                   KL1_I2S0_CLK_ENABLE_BIT);
130         (void)MACIO_IN32(KEYLARGO_FCR1);
131         udelay(10);
132 }
133 
134 static void rackmeter_set_default_pattern(struct rackmeter *rm)
135 {
136         int i;
137 
138         for (i = 0; i < 16; i++) {
139                 if (i < 8)
140                         rm->ubuf[i] = (i & 1) * 255;
141                 else
142                         rm->ubuf[i] = ((~i) & 1) * 255;
143         }
144 }
145 
146 static void rackmeter_do_pause(struct rackmeter *rm, int pause)
147 {
148         struct rackmeter_dma *rdma = rm->dma_buf_v;
149 
150         pr_debug("rackmeter: %s\n", pause ? "paused" : "started");
151 
152         rm->paused = pause;
153         if (pause) {
154                 DBDMA_DO_STOP(rm->dma_regs);
155                 return;
156         }
157         memset(rdma->buf1, 0, SAMPLE_COUNT & sizeof(u32));
158         memset(rdma->buf2, 0, SAMPLE_COUNT & sizeof(u32));
159 
160         rm->dma_buf_v->mark = 0;
161 
162         mb();
163         out_le32(&rm->dma_regs->cmdptr_hi, 0);
164         out_le32(&rm->dma_regs->cmdptr, rm->dma_buf_p);
165         out_le32(&rm->dma_regs->control, (RUN << 16) | RUN);
166 }
167 
168 static void rackmeter_setup_dbdma(struct rackmeter *rm)
169 {
170         struct rackmeter_dma *db = rm->dma_buf_v;
171         struct dbdma_cmd *cmd = db->cmd;
172 
173         /* Make sure dbdma is reset */
174         DBDMA_DO_RESET(rm->dma_regs);
175 
176         pr_debug("rackmeter: mark offset=0x%zx\n",
177                  offsetof(struct rackmeter_dma, mark));
178         pr_debug("rackmeter: buf1 offset=0x%zx\n",
179                  offsetof(struct rackmeter_dma, buf1));
180         pr_debug("rackmeter: buf2 offset=0x%zx\n",
181                  offsetof(struct rackmeter_dma, buf2));
182 
183         /* Prepare 4 dbdma commands for the 2 buffers */
184         memset(cmd, 0, 4 * sizeof(struct dbdma_cmd));
185         st_le16(&cmd->req_count, 4);
186         st_le16(&cmd->command, STORE_WORD | INTR_ALWAYS | KEY_SYSTEM);
187         st_le32(&cmd->phy_addr, rm->dma_buf_p +
188                 offsetof(struct rackmeter_dma, mark));
189         st_le32(&cmd->cmd_dep, 0x02000000);
190         cmd++;
191 
192         st_le16(&cmd->req_count, SAMPLE_COUNT * 4);
193         st_le16(&cmd->command, OUTPUT_MORE);
194         st_le32(&cmd->phy_addr, rm->dma_buf_p +
195                 offsetof(struct rackmeter_dma, buf1));
196         cmd++;
197 
198         st_le16(&cmd->req_count, 4);
199         st_le16(&cmd->command, STORE_WORD | INTR_ALWAYS | KEY_SYSTEM);
200         st_le32(&cmd->phy_addr, rm->dma_buf_p +
201                 offsetof(struct rackmeter_dma, mark));
202         st_le32(&cmd->cmd_dep, 0x01000000);
203         cmd++;
204 
205         st_le16(&cmd->req_count, SAMPLE_COUNT * 4);
206         st_le16(&cmd->command, OUTPUT_MORE | BR_ALWAYS);
207         st_le32(&cmd->phy_addr, rm->dma_buf_p +
208                 offsetof(struct rackmeter_dma, buf2));
209         st_le32(&cmd->cmd_dep, rm->dma_buf_p);
210 
211         rackmeter_do_pause(rm, 0);
212 }
213 
214 static void rackmeter_do_timer(struct work_struct *work)
215 {
216         struct rackmeter_cpu *rcpu =
217                 container_of(work, struct rackmeter_cpu, sniffer.work);
218         struct rackmeter *rm = rcpu->rm;
219         unsigned int cpu = smp_processor_id();
220         cputime64_t cur_jiffies, total_idle_ticks;
221         unsigned int total_ticks, idle_ticks;
222         int i, offset, load, cumm, pause;
223 
224         cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
225         total_ticks = (unsigned int) (cur_jiffies - rcpu->prev_wall);
226         rcpu->prev_wall = cur_jiffies;
227 
228         total_idle_ticks = get_cpu_idle_time(cpu);
229         idle_ticks = (unsigned int) (total_idle_ticks - rcpu->prev_idle);
230         rcpu->prev_idle = total_idle_ticks;
231 
232         /* We do a very dumb calculation to update the LEDs for now,
233          * we'll do better once we have actual PWM implemented
234          */
235         load = (9 * (total_ticks - idle_ticks)) / total_ticks;
236 
237         offset = cpu << 3;
238         cumm = 0;
239         for (i = 0; i < 8; i++) {
240                 u8 ub = (load > i) ? 0xff : 0;
241                 rm->ubuf[i + offset] = ub;
242                 cumm |= ub;
243         }
244         rcpu->zero = (cumm == 0);
245 
246         /* Now check if LEDs are all 0, we can stop DMA */
247         pause = (rm->cpu[0].zero && rm->cpu[1].zero);
248         if (pause != rm->paused) {
249                 mutex_lock(&rm->sem);
250                 pause = (rm->cpu[0].zero && rm->cpu[1].zero);
251                 rackmeter_do_pause(rm, pause);
252                 mutex_unlock(&rm->sem);
253         }
254         schedule_delayed_work_on(cpu, &rcpu->sniffer,
255                                  msecs_to_jiffies(CPU_SAMPLING_RATE));
256 }
257 
258 static void rackmeter_init_cpu_sniffer(struct rackmeter *rm)
259 {
260         unsigned int cpu;
261 
262         /* This driver works only with 1 or 2 CPUs numbered 0 and 1,
263          * but that's really all we have on Apple Xserve. It doesn't
264          * play very nice with CPU hotplug neither but we don't do that
265          * on those machines yet
266          */
267 
268         rm->cpu[0].rm = rm;
269         INIT_DELAYED_WORK(&rm->cpu[0].sniffer, rackmeter_do_timer);
270         rm->cpu[1].rm = rm;
271         INIT_DELAYED_WORK(&rm->cpu[1].sniffer, rackmeter_do_timer);
272 
273         for_each_online_cpu(cpu) {
274                 struct rackmeter_cpu *rcpu;
275 
276                 if (cpu > 1)
277                         continue;
278                 rcpu = &rm->cpu[cpu];
279                 rcpu->prev_idle = get_cpu_idle_time(cpu);
280                 rcpu->prev_wall = jiffies64_to_cputime64(get_jiffies_64());
281                 schedule_delayed_work_on(cpu, &rm->cpu[cpu].sniffer,
282                                          msecs_to_jiffies(CPU_SAMPLING_RATE));
283         }
284 }
285 
286 static void rackmeter_stop_cpu_sniffer(struct rackmeter *rm)
287 {
288         cancel_delayed_work_sync(&rm->cpu[0].sniffer);
289         cancel_delayed_work_sync(&rm->cpu[1].sniffer);
290 }
291 
292 static int rackmeter_setup(struct rackmeter *rm)
293 {
294         pr_debug("rackmeter: setting up i2s..\n");
295         rackmeter_setup_i2s(rm);
296 
297         pr_debug("rackmeter: setting up default pattern..\n");
298         rackmeter_set_default_pattern(rm);
299 
300         pr_debug("rackmeter: setting up dbdma..\n");
301         rackmeter_setup_dbdma(rm);
302 
303         pr_debug("rackmeter: start CPU measurements..\n");
304         rackmeter_init_cpu_sniffer(rm);
305 
306         printk(KERN_INFO "RackMeter initialized\n");
307 
308         return 0;
309 }
310 
311 /*  XXX FIXME: No PWM yet, this is 0/1 */
312 static u32 rackmeter_calc_sample(struct rackmeter *rm, unsigned int index)
313 {
314         int led;
315         u32 sample = 0;
316 
317         for (led = 0; led < 16; led++) {
318                 sample >>= 1;
319                 sample |= ((rm->ubuf[led] >= 0x80) << 15);
320         }
321         return (sample << 17) | (sample >> 15);
322 }
323 
324 static irqreturn_t rackmeter_irq(int irq, void *arg)
325 {
326         struct rackmeter *rm = arg;
327         struct rackmeter_dma *db = rm->dma_buf_v;
328         unsigned int mark, i;
329         u32 *buf;
330 
331         /* Flush PCI buffers with an MMIO read. Maybe we could actually
332          * check the status one day ... in case things go wrong, though
333          * this never happened to me
334          */
335         (void)in_le32(&rm->dma_regs->status);
336 
337         /* Make sure the CPU gets us in order */
338         rmb();
339 
340         /* Read mark */
341         mark = db->mark;
342         if (mark != 1 && mark != 2) {
343                 printk(KERN_WARNING "rackmeter: Incorrect DMA mark 0x%08x\n",
344                        mark);
345                 /* We allow for 3 errors like that (stale DBDMA irqs) */
346                 if (++rm->stale_irq > 3) {
347                         printk(KERN_ERR "rackmeter: Too many errors,"
348                                " stopping DMA\n");
349                         DBDMA_DO_RESET(rm->dma_regs);
350                 }
351                 return IRQ_HANDLED;
352         }
353 
354         /* Next buffer we need to fill is mark value */
355         buf = mark == 1 ? db->buf1 : db->buf2;
356 
357         /* Fill it now. This routine converts the 8 bits depth sample array
358          * into the PWM bitmap for each LED.
359          */
360         for (i = 0; i < SAMPLE_COUNT; i++)
361                 buf[i] = rackmeter_calc_sample(rm, i);
362 
363 
364         return IRQ_HANDLED;
365 }
366 
367 static int rackmeter_probe(struct macio_dev* mdev,
368                            const struct of_device_id *match)
369 {
370         struct device_node *i2s = NULL, *np = NULL;
371         struct rackmeter *rm = NULL;
372         struct resource ri2s, rdma;
373         int rc = -ENODEV;
374 
375         pr_debug("rackmeter_probe()\n");
376 
377         /* Get i2s-a node */
378         while ((i2s = of_get_next_child(mdev->ofdev.dev.of_node, i2s)) != NULL)
379                if (strcmp(i2s->name, "i2s-a") == 0)
380                        break;
381         if (i2s == NULL) {
382                 pr_debug("  i2s-a child not found\n");
383                 goto bail;
384         }
385         /* Get lightshow or virtual sound */
386         while ((np = of_get_next_child(i2s, np)) != NULL) {
387                if (strcmp(np->name, "lightshow") == 0)
388                        break;
389                if ((strcmp(np->name, "sound") == 0) &&
390                    of_get_property(np, "virtual", NULL) != NULL)
391                        break;
392         }
393         if (np == NULL) {
394                 pr_debug("  lightshow or sound+virtual child not found\n");
395                 goto bail;
396         }
397 
398         /* Create and initialize our instance data */
399         rm = kzalloc(sizeof(struct rackmeter), GFP_KERNEL);
400         if (rm == NULL) {
401                 printk(KERN_ERR "rackmeter: failed to allocate memory !\n");
402                 rc = -ENOMEM;
403                 goto bail_release;
404         }
405         rm->mdev = mdev;
406         rm->i2s = i2s;
407         mutex_init(&rm->sem);
408         dev_set_drvdata(&mdev->ofdev.dev, rm);
409         /* Check resources availability. We need at least resource 0 and 1 */
410 #if 0 /* Use that when i2s-a is finally an mdev per-se */
411         if (macio_resource_count(mdev) < 2 || macio_irq_count(mdev) < 2) {
412                 printk(KERN_ERR
413                        "rackmeter: found match but lacks resources: %s"
414                        " (%d resources, %d interrupts)\n",
415                        mdev->ofdev.node->full_name);
416                 rc = -ENXIO;
417                 goto bail_free;
418         }
419         if (macio_request_resources(mdev, "rackmeter")) {
420                 printk(KERN_ERR
421                        "rackmeter: failed to request resources: %s\n",
422                        mdev->ofdev.node->full_name);
423                 rc = -EBUSY;
424                 goto bail_free;
425         }
426         rm->irq = macio_irq(mdev, 1);
427 #else
428         rm->irq = irq_of_parse_and_map(i2s, 1);
429         if (rm->irq == NO_IRQ ||
430             of_address_to_resource(i2s, 0, &ri2s) ||
431             of_address_to_resource(i2s, 1, &rdma)) {
432                 printk(KERN_ERR
433                        "rackmeter: found match but lacks resources: %s",
434                        mdev->ofdev.dev.of_node->full_name);
435                 rc = -ENXIO;
436                 goto bail_free;
437         }
438 #endif
439 
440         pr_debug("  i2s @0x%08x\n", (unsigned int)ri2s.start);
441         pr_debug("  dma @0x%08x\n", (unsigned int)rdma.start);
442         pr_debug("  irq %d\n", rm->irq);
443 
444         rm->ubuf = (u8 *)__get_free_page(GFP_KERNEL);
445         if (rm->ubuf == NULL) {
446                 printk(KERN_ERR
447                        "rackmeter: failed to allocate samples page !\n");
448                 rc = -ENOMEM;
449                 goto bail_release;
450         }
451 
452         rm->dma_buf_v = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev,
453                                            sizeof(struct rackmeter_dma),
454                                            &rm->dma_buf_p, GFP_KERNEL);
455         if (rm->dma_buf_v == NULL) {
456                 printk(KERN_ERR
457                        "rackmeter: failed to allocate dma buffer !\n");
458                 rc = -ENOMEM;
459                 goto bail_free_samples;
460         }
461 #if 0
462         rm->i2s_regs = ioremap(macio_resource_start(mdev, 0), 0x1000);
463 #else
464         rm->i2s_regs = ioremap(ri2s.start, 0x1000);
465 #endif
466         if (rm->i2s_regs == NULL) {
467                 printk(KERN_ERR
468                        "rackmeter: failed to map i2s registers !\n");
469                 rc = -ENXIO;
470                 goto bail_free_dma;
471         }
472 #if 0
473         rm->dma_regs = ioremap(macio_resource_start(mdev, 1), 0x100);
474 #else
475         rm->dma_regs = ioremap(rdma.start, 0x100);
476 #endif
477         if (rm->dma_regs == NULL) {
478                 printk(KERN_ERR
479                        "rackmeter: failed to map dma registers !\n");
480                 rc = -ENXIO;
481                 goto bail_unmap_i2s;
482         }
483 
484         rc = rackmeter_setup(rm);
485         if (rc) {
486                 printk(KERN_ERR
487                        "rackmeter: failed to initialize !\n");
488                 rc = -ENXIO;
489                 goto bail_unmap_dma;
490         }
491 
492         rc = request_irq(rm->irq, rackmeter_irq, 0, "rackmeter", rm);
493         if (rc != 0) {
494                 printk(KERN_ERR
495                        "rackmeter: failed to request interrupt !\n");
496                 goto bail_stop_dma;
497         }
498         of_node_put(np);
499         return 0;
500 
501  bail_stop_dma:
502         DBDMA_DO_RESET(rm->dma_regs);
503  bail_unmap_dma:
504         iounmap(rm->dma_regs);
505  bail_unmap_i2s:
506         iounmap(rm->i2s_regs);
507  bail_free_dma:
508         dma_free_coherent(&macio_get_pci_dev(mdev)->dev,
509                           sizeof(struct rackmeter_dma),
510                           rm->dma_buf_v, rm->dma_buf_p);
511  bail_free_samples:
512         free_page((unsigned long)rm->ubuf);
513  bail_release:
514 #if 0
515         macio_release_resources(mdev);
516 #endif
517  bail_free:
518         kfree(rm);
519  bail:
520         of_node_put(i2s);
521         of_node_put(np);
522         dev_set_drvdata(&mdev->ofdev.dev, NULL);
523         return rc;
524 }
525 
526 static int rackmeter_remove(struct macio_dev* mdev)
527 {
528         struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev);
529 
530         /* Stop CPU sniffer timer & work queues */
531         rackmeter_stop_cpu_sniffer(rm);
532 
533         /* Clear reference to private data */
534         dev_set_drvdata(&mdev->ofdev.dev, NULL);
535 
536         /* Stop/reset dbdma */
537         DBDMA_DO_RESET(rm->dma_regs);
538 
539         /* Release the IRQ */
540         free_irq(rm->irq, rm);
541 
542         /* Unmap registers */
543         iounmap(rm->dma_regs);
544         iounmap(rm->i2s_regs);
545 
546         /* Free DMA */
547         dma_free_coherent(&macio_get_pci_dev(mdev)->dev,
548                           sizeof(struct rackmeter_dma),
549                           rm->dma_buf_v, rm->dma_buf_p);
550 
551         /* Free samples */
552         free_page((unsigned long)rm->ubuf);
553 
554 #if 0
555         /* Release resources */
556         macio_release_resources(mdev);
557 #endif
558 
559         /* Get rid of me */
560         kfree(rm);
561 
562         return 0;
563 }
564 
565 static int rackmeter_shutdown(struct macio_dev* mdev)
566 {
567         struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev);
568 
569         if (rm == NULL)
570                 return -ENODEV;
571 
572         /* Stop CPU sniffer timer & work queues */
573         rackmeter_stop_cpu_sniffer(rm);
574 
575         /* Stop/reset dbdma */
576         DBDMA_DO_RESET(rm->dma_regs);
577 
578         return 0;
579 }
580 
581 static struct of_device_id rackmeter_match[] = {
582         { .name = "i2s" },
583         { }
584 };
585 
586 static struct macio_driver rackmeter_driver = {
587         .driver = {
588                 .name = "rackmeter",
589                 .owner = THIS_MODULE,
590                 .of_match_table = rackmeter_match,
591         },
592         .probe = rackmeter_probe,
593         .remove = rackmeter_remove,
594         .shutdown = rackmeter_shutdown,
595 };
596 
597 
598 static int __init rackmeter_init(void)
599 {
600         pr_debug("rackmeter_init()\n");
601 
602         return macio_register_driver(&rackmeter_driver);
603 }
604 
605 static void __exit rackmeter_exit(void)
606 {
607         pr_debug("rackmeter_exit()\n");
608 
609         macio_unregister_driver(&rackmeter_driver);
610 }
611 
612 module_init(rackmeter_init);
613 module_exit(rackmeter_exit);
614 
615 
616 MODULE_LICENSE("GPL");
617 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
618 MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel");
619 

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