Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

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, ARRAY_SIZE(rdma->buf1));
158         memset(rdma->buf2, 0, ARRAY_SIZE(rdma->buf2));
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         cmd->req_count = cpu_to_le16(4);
186         cmd->command = cpu_to_le16(STORE_WORD | INTR_ALWAYS | KEY_SYSTEM);
187         cmd->phy_addr = cpu_to_le32(rm->dma_buf_p +
188                 offsetof(struct rackmeter_dma, mark));
189         cmd->cmd_dep = cpu_to_le32(0x02000000);
190         cmd++;
191 
192         cmd->req_count = cpu_to_le16(SAMPLE_COUNT * 4);
193         cmd->command = cpu_to_le16(OUTPUT_MORE);
194         cmd->phy_addr = cpu_to_le32(rm->dma_buf_p +
195                 offsetof(struct rackmeter_dma, buf1));
196         cmd++;
197 
198         cmd->req_count = cpu_to_le16(4);
199         cmd->command = cpu_to_le16(STORE_WORD | INTR_ALWAYS | KEY_SYSTEM);
200         cmd->phy_addr = cpu_to_le32(rm->dma_buf_p +
201                 offsetof(struct rackmeter_dma, mark));
202         cmd->cmd_dep = cpu_to_le32(0x01000000);
203         cmd++;
204 
205         cmd->req_count = cpu_to_le16(SAMPLE_COUNT * 4);
206         cmd->command = cpu_to_le16(OUTPUT_MORE | BR_ALWAYS);
207         cmd->phy_addr = cpu_to_le32(rm->dma_buf_p +
208                 offsetof(struct rackmeter_dma, buf2));
209         cmd->cmd_dep = cpu_to_le32(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         idle_ticks = min(idle_ticks, total_ticks);
231         rcpu->prev_idle = total_idle_ticks;
232 
233         /* We do a very dumb calculation to update the LEDs for now,
234          * we'll do better once we have actual PWM implemented
235          */
236         load = (9 * (total_ticks - idle_ticks)) / total_ticks;
237 
238         offset = cpu << 3;
239         cumm = 0;
240         for (i = 0; i < 8; i++) {
241                 u8 ub = (load > i) ? 0xff : 0;
242                 rm->ubuf[i + offset] = ub;
243                 cumm |= ub;
244         }
245         rcpu->zero = (cumm == 0);
246 
247         /* Now check if LEDs are all 0, we can stop DMA */
248         pause = (rm->cpu[0].zero && rm->cpu[1].zero);
249         if (pause != rm->paused) {
250                 mutex_lock(&rm->sem);
251                 pause = (rm->cpu[0].zero && rm->cpu[1].zero);
252                 rackmeter_do_pause(rm, pause);
253                 mutex_unlock(&rm->sem);
254         }
255         schedule_delayed_work_on(cpu, &rcpu->sniffer,
256                                  msecs_to_jiffies(CPU_SAMPLING_RATE));
257 }
258 
259 static void rackmeter_init_cpu_sniffer(struct rackmeter *rm)
260 {
261         unsigned int cpu;
262 
263         /* This driver works only with 1 or 2 CPUs numbered 0 and 1,
264          * but that's really all we have on Apple Xserve. It doesn't
265          * play very nice with CPU hotplug neither but we don't do that
266          * on those machines yet
267          */
268 
269         rm->cpu[0].rm = rm;
270         INIT_DELAYED_WORK(&rm->cpu[0].sniffer, rackmeter_do_timer);
271         rm->cpu[1].rm = rm;
272         INIT_DELAYED_WORK(&rm->cpu[1].sniffer, rackmeter_do_timer);
273 
274         for_each_online_cpu(cpu) {
275                 struct rackmeter_cpu *rcpu;
276 
277                 if (cpu > 1)
278                         continue;
279                 rcpu = &rm->cpu[cpu];
280                 rcpu->prev_idle = get_cpu_idle_time(cpu);
281                 rcpu->prev_wall = jiffies64_to_cputime64(get_jiffies_64());
282                 schedule_delayed_work_on(cpu, &rm->cpu[cpu].sniffer,
283                                          msecs_to_jiffies(CPU_SAMPLING_RATE));
284         }
285 }
286 
287 static void rackmeter_stop_cpu_sniffer(struct rackmeter *rm)
288 {
289         cancel_delayed_work_sync(&rm->cpu[0].sniffer);
290         cancel_delayed_work_sync(&rm->cpu[1].sniffer);
291 }
292 
293 static int rackmeter_setup(struct rackmeter *rm)
294 {
295         pr_debug("rackmeter: setting up i2s..\n");
296         rackmeter_setup_i2s(rm);
297 
298         pr_debug("rackmeter: setting up default pattern..\n");
299         rackmeter_set_default_pattern(rm);
300 
301         pr_debug("rackmeter: setting up dbdma..\n");
302         rackmeter_setup_dbdma(rm);
303 
304         pr_debug("rackmeter: start CPU measurements..\n");
305         rackmeter_init_cpu_sniffer(rm);
306 
307         printk(KERN_INFO "RackMeter initialized\n");
308 
309         return 0;
310 }
311 
312 /*  XXX FIXME: No PWM yet, this is 0/1 */
313 static u32 rackmeter_calc_sample(struct rackmeter *rm, unsigned int index)
314 {
315         int led;
316         u32 sample = 0;
317 
318         for (led = 0; led < 16; led++) {
319                 sample >>= 1;
320                 sample |= ((rm->ubuf[led] >= 0x80) << 15);
321         }
322         return (sample << 17) | (sample >> 15);
323 }
324 
325 static irqreturn_t rackmeter_irq(int irq, void *arg)
326 {
327         struct rackmeter *rm = arg;
328         struct rackmeter_dma *db = rm->dma_buf_v;
329         unsigned int mark, i;
330         u32 *buf;
331 
332         /* Flush PCI buffers with an MMIO read. Maybe we could actually
333          * check the status one day ... in case things go wrong, though
334          * this never happened to me
335          */
336         (void)in_le32(&rm->dma_regs->status);
337 
338         /* Make sure the CPU gets us in order */
339         rmb();
340 
341         /* Read mark */
342         mark = db->mark;
343         if (mark != 1 && mark != 2) {
344                 printk(KERN_WARNING "rackmeter: Incorrect DMA mark 0x%08x\n",
345                        mark);
346                 /* We allow for 3 errors like that (stale DBDMA irqs) */
347                 if (++rm->stale_irq > 3) {
348                         printk(KERN_ERR "rackmeter: Too many errors,"
349                                " stopping DMA\n");
350                         DBDMA_DO_RESET(rm->dma_regs);
351                 }
352                 return IRQ_HANDLED;
353         }
354 
355         /* Next buffer we need to fill is mark value */
356         buf = mark == 1 ? db->buf1 : db->buf2;
357 
358         /* Fill it now. This routine converts the 8 bits depth sample array
359          * into the PWM bitmap for each LED.
360          */
361         for (i = 0; i < SAMPLE_COUNT; i++)
362                 buf[i] = rackmeter_calc_sample(rm, i);
363 
364 
365         return IRQ_HANDLED;
366 }
367 
368 static int rackmeter_probe(struct macio_dev* mdev,
369                            const struct of_device_id *match)
370 {
371         struct device_node *i2s = NULL, *np = NULL;
372         struct rackmeter *rm = NULL;
373         struct resource ri2s, rdma;
374         int rc = -ENODEV;
375 
376         pr_debug("rackmeter_probe()\n");
377 
378         /* Get i2s-a node */
379         while ((i2s = of_get_next_child(mdev->ofdev.dev.of_node, i2s)) != NULL)
380                if (strcmp(i2s->name, "i2s-a") == 0)
381                        break;
382         if (i2s == NULL) {
383                 pr_debug("  i2s-a child not found\n");
384                 goto bail;
385         }
386         /* Get lightshow or virtual sound */
387         while ((np = of_get_next_child(i2s, np)) != NULL) {
388                if (strcmp(np->name, "lightshow") == 0)
389                        break;
390                if ((strcmp(np->name, "sound") == 0) &&
391                    of_get_property(np, "virtual", NULL) != NULL)
392                        break;
393         }
394         if (np == NULL) {
395                 pr_debug("  lightshow or sound+virtual child not found\n");
396                 goto bail;
397         }
398 
399         /* Create and initialize our instance data */
400         rm = kzalloc(sizeof(struct rackmeter), GFP_KERNEL);
401         if (rm == NULL) {
402                 printk(KERN_ERR "rackmeter: failed to allocate memory !\n");
403                 rc = -ENOMEM;
404                 goto bail_release;
405         }
406         rm->mdev = mdev;
407         rm->i2s = i2s;
408         mutex_init(&rm->sem);
409         dev_set_drvdata(&mdev->ofdev.dev, rm);
410         /* Check resources availability. We need at least resource 0 and 1 */
411 #if 0 /* Use that when i2s-a is finally an mdev per-se */
412         if (macio_resource_count(mdev) < 2 || macio_irq_count(mdev) < 2) {
413                 printk(KERN_ERR
414                        "rackmeter: found match but lacks resources: %s"
415                        " (%d resources, %d interrupts)\n",
416                        mdev->ofdev.node->full_name);
417                 rc = -ENXIO;
418                 goto bail_free;
419         }
420         if (macio_request_resources(mdev, "rackmeter")) {
421                 printk(KERN_ERR
422                        "rackmeter: failed to request resources: %s\n",
423                        mdev->ofdev.node->full_name);
424                 rc = -EBUSY;
425                 goto bail_free;
426         }
427         rm->irq = macio_irq(mdev, 1);
428 #else
429         rm->irq = irq_of_parse_and_map(i2s, 1);
430         if (rm->irq == NO_IRQ ||
431             of_address_to_resource(i2s, 0, &ri2s) ||
432             of_address_to_resource(i2s, 1, &rdma)) {
433                 printk(KERN_ERR
434                        "rackmeter: found match but lacks resources: %s",
435                        mdev->ofdev.dev.of_node->full_name);
436                 rc = -ENXIO;
437                 goto bail_free;
438         }
439 #endif
440 
441         pr_debug("  i2s @0x%08x\n", (unsigned int)ri2s.start);
442         pr_debug("  dma @0x%08x\n", (unsigned int)rdma.start);
443         pr_debug("  irq %d\n", rm->irq);
444 
445         rm->ubuf = (u8 *)__get_free_page(GFP_KERNEL);
446         if (rm->ubuf == NULL) {
447                 printk(KERN_ERR
448                        "rackmeter: failed to allocate samples page !\n");
449                 rc = -ENOMEM;
450                 goto bail_release;
451         }
452 
453         rm->dma_buf_v = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev,
454                                            sizeof(struct rackmeter_dma),
455                                            &rm->dma_buf_p, GFP_KERNEL);
456         if (rm->dma_buf_v == NULL) {
457                 printk(KERN_ERR
458                        "rackmeter: failed to allocate dma buffer !\n");
459                 rc = -ENOMEM;
460                 goto bail_free_samples;
461         }
462 #if 0
463         rm->i2s_regs = ioremap(macio_resource_start(mdev, 0), 0x1000);
464 #else
465         rm->i2s_regs = ioremap(ri2s.start, 0x1000);
466 #endif
467         if (rm->i2s_regs == NULL) {
468                 printk(KERN_ERR
469                        "rackmeter: failed to map i2s registers !\n");
470                 rc = -ENXIO;
471                 goto bail_free_dma;
472         }
473 #if 0
474         rm->dma_regs = ioremap(macio_resource_start(mdev, 1), 0x100);
475 #else
476         rm->dma_regs = ioremap(rdma.start, 0x100);
477 #endif
478         if (rm->dma_regs == NULL) {
479                 printk(KERN_ERR
480                        "rackmeter: failed to map dma registers !\n");
481                 rc = -ENXIO;
482                 goto bail_unmap_i2s;
483         }
484 
485         rc = rackmeter_setup(rm);
486         if (rc) {
487                 printk(KERN_ERR
488                        "rackmeter: failed to initialize !\n");
489                 rc = -ENXIO;
490                 goto bail_unmap_dma;
491         }
492 
493         rc = request_irq(rm->irq, rackmeter_irq, 0, "rackmeter", rm);
494         if (rc != 0) {
495                 printk(KERN_ERR
496                        "rackmeter: failed to request interrupt !\n");
497                 goto bail_stop_dma;
498         }
499         of_node_put(np);
500         return 0;
501 
502  bail_stop_dma:
503         DBDMA_DO_RESET(rm->dma_regs);
504  bail_unmap_dma:
505         iounmap(rm->dma_regs);
506  bail_unmap_i2s:
507         iounmap(rm->i2s_regs);
508  bail_free_dma:
509         dma_free_coherent(&macio_get_pci_dev(mdev)->dev,
510                           sizeof(struct rackmeter_dma),
511                           rm->dma_buf_v, rm->dma_buf_p);
512  bail_free_samples:
513         free_page((unsigned long)rm->ubuf);
514  bail_release:
515 #if 0
516         macio_release_resources(mdev);
517 #endif
518  bail_free:
519         kfree(rm);
520  bail:
521         of_node_put(i2s);
522         of_node_put(np);
523         dev_set_drvdata(&mdev->ofdev.dev, NULL);
524         return rc;
525 }
526 
527 static int rackmeter_remove(struct macio_dev* mdev)
528 {
529         struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev);
530 
531         /* Stop CPU sniffer timer & work queues */
532         rackmeter_stop_cpu_sniffer(rm);
533 
534         /* Clear reference to private data */
535         dev_set_drvdata(&mdev->ofdev.dev, NULL);
536 
537         /* Stop/reset dbdma */
538         DBDMA_DO_RESET(rm->dma_regs);
539 
540         /* Release the IRQ */
541         free_irq(rm->irq, rm);
542 
543         /* Unmap registers */
544         iounmap(rm->dma_regs);
545         iounmap(rm->i2s_regs);
546 
547         /* Free DMA */
548         dma_free_coherent(&macio_get_pci_dev(mdev)->dev,
549                           sizeof(struct rackmeter_dma),
550                           rm->dma_buf_v, rm->dma_buf_p);
551 
552         /* Free samples */
553         free_page((unsigned long)rm->ubuf);
554 
555 #if 0
556         /* Release resources */
557         macio_release_resources(mdev);
558 #endif
559 
560         /* Get rid of me */
561         kfree(rm);
562 
563         return 0;
564 }
565 
566 static int rackmeter_shutdown(struct macio_dev* mdev)
567 {
568         struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev);
569 
570         if (rm == NULL)
571                 return -ENODEV;
572 
573         /* Stop CPU sniffer timer & work queues */
574         rackmeter_stop_cpu_sniffer(rm);
575 
576         /* Stop/reset dbdma */
577         DBDMA_DO_RESET(rm->dma_regs);
578 
579         return 0;
580 }
581 
582 static struct of_device_id rackmeter_match[] = {
583         { .name = "i2s" },
584         { }
585 };
586 MODULE_DEVICE_TABLE(of, rackmeter_match);
587 
588 static struct macio_driver rackmeter_driver = {
589         .driver = {
590                 .name = "rackmeter",
591                 .owner = THIS_MODULE,
592                 .of_match_table = rackmeter_match,
593         },
594         .probe = rackmeter_probe,
595         .remove = rackmeter_remove,
596         .shutdown = rackmeter_shutdown,
597 };
598 
599 
600 static int __init rackmeter_init(void)
601 {
602         pr_debug("rackmeter_init()\n");
603 
604         return macio_register_driver(&rackmeter_driver);
605 }
606 
607 static void __exit rackmeter_exit(void)
608 {
609         pr_debug("rackmeter_exit()\n");
610 
611         macio_unregister_driver(&rackmeter_driver);
612 }
613 
614 module_init(rackmeter_init);
615 module_exit(rackmeter_exit);
616 
617 
618 MODULE_LICENSE("GPL");
619 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
620 MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel");
621 

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