/* * RackMac vu-meter driver * * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp. * <benh@kernel.crashing.org> * * Released under the term of the GNU GPL v2. * * Support the CPU-meter LEDs of the Xserve G5 * * TODO: Implement PWM to do variable intensity and provide userland * interface for fun. Also, the CPU-meter could be made nicer by being * a bit less "immediate" but giving instead a more average load over * time. Patches welcome :-) * */ #undef DEBUG #include <linux/types.h> #include <linux/kernel.h> #include <linux/device.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/dma-mapping.h> #include <linux/kernel_stat.h> #include <asm/io.h> #include <asm/prom.h> #include <asm/machdep.h> #include <asm/pmac_feature.h> #include <asm/dbdma.h> #include <asm/macio.h> #include <asm/keylargo.h> /* Number of samples in a sample buffer */ #define SAMPLE_COUNT 256 /* CPU meter sampling rate in ms */ #define CPU_SAMPLING_RATE 250 struct rackmeter_dma { struct dbdma_cmd cmd[4] ____cacheline_aligned; u32 mark ____cacheline_aligned; u32 buf1[SAMPLE_COUNT] ____cacheline_aligned; u32 buf2[SAMPLE_COUNT] ____cacheline_aligned; } ____cacheline_aligned; struct rackmeter_cpu { struct delayed_work sniffer; struct rackmeter *rm; cputime64_t prev_wall; cputime64_t prev_idle; int zero; } ____cacheline_aligned; struct rackmeter { struct macio_dev *mdev; unsigned int irq; struct device_node *i2s; u8 *ubuf; struct dbdma_regs __iomem *dma_regs; void __iomem *i2s_regs; dma_addr_t dma_buf_p; struct rackmeter_dma *dma_buf_v; int stale_irq; struct rackmeter_cpu cpu[2]; int paused; struct mutex sem; }; /* To be set as a tunable */ static int rackmeter_ignore_nice; /* This GPIO is whacked by the OS X driver when initializing */ #define RACKMETER_MAGIC_GPIO 0x78 /* This is copied from cpufreq_ondemand, maybe we should put it in * a common header somewhere */ static inline cputime64_t get_cpu_idle_time(unsigned int cpu) { cputime64_t retval; retval = cputime64_add(kstat_cpu(cpu).cpustat.idle, kstat_cpu(cpu).cpustat.iowait); if (rackmeter_ignore_nice) retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice); return retval; } static void rackmeter_setup_i2s(struct rackmeter *rm) { struct macio_chip *macio = rm->mdev->bus->chip; /* First whack magic GPIO */ pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, RACKMETER_MAGIC_GPIO, 5); /* Call feature code to enable the sound channel and the proper * clock sources */ pmac_call_feature(PMAC_FTR_SOUND_CHIP_ENABLE, rm->i2s, 0, 1); /* Power i2s and stop i2s clock. We whack MacIO FCRs directly for now. * This is a bit racy, thus we should add new platform functions to * handle that. snd-aoa needs that too */ MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_ENABLE); MACIO_BIC(KEYLARGO_FCR1, KL1_I2S0_CLK_ENABLE_BIT); (void)MACIO_IN32(KEYLARGO_FCR1); udelay(10); /* Then setup i2s. For now, we use the same magic value that * the OS X driver seems to use. We might want to play around * with the clock divisors later */ out_le32(rm->i2s_regs + 0x10, 0x01fa0000); (void)in_le32(rm->i2s_regs + 0x10); udelay(10); /* Fully restart i2s*/ MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_CELL_ENABLE | KL1_I2S0_CLK_ENABLE_BIT); (void)MACIO_IN32(KEYLARGO_FCR1); udelay(10); } static void rackmeter_set_default_pattern(struct rackmeter *rm) { int i; for (i = 0; i < 16; i++) { if (i < 8) rm->ubuf[i] = (i & 1) * 255; else rm->ubuf[i] = ((~i) & 1) * 255; } } static void rackmeter_do_pause(struct rackmeter *rm, int pause) { struct rackmeter_dma *rdma = rm->dma_buf_v; pr_debug("rackmeter: %s\n", pause ? "paused" : "started"); rm->paused = pause; if (pause) { DBDMA_DO_STOP(rm->dma_regs); return; } memset(rdma->buf1, 0, SAMPLE_COUNT & sizeof(u32)); memset(rdma->buf2, 0, SAMPLE_COUNT & sizeof(u32)); rm->dma_buf_v->mark = 0; mb(); out_le32(&rm->dma_regs->cmdptr_hi, 0); out_le32(&rm->dma_regs->cmdptr, rm->dma_buf_p); out_le32(&rm->dma_regs->control, (RUN << 16) | RUN); } static void rackmeter_setup_dbdma(struct rackmeter *rm) { struct rackmeter_dma *db = rm->dma_buf_v; struct dbdma_cmd *cmd = db->cmd; /* Make sure dbdma is reset */ DBDMA_DO_RESET(rm->dma_regs); pr_debug("rackmeter: mark offset=0x%zx\n", offsetof(struct rackmeter_dma, mark)); pr_debug("rackmeter: buf1 offset=0x%zx\n", offsetof(struct rackmeter_dma, buf1)); pr_debug("rackmeter: buf2 offset=0x%zx\n", offsetof(struct rackmeter_dma, buf2)); /* Prepare 4 dbdma commands for the 2 buffers */ memset(cmd, 0, 4 * sizeof(struct dbdma_cmd)); st_le16(&cmd->req_count, 4); st_le16(&cmd->command, STORE_WORD | INTR_ALWAYS | KEY_SYSTEM); st_le32(&cmd->phy_addr, rm->dma_buf_p + offsetof(struct rackmeter_dma, mark)); st_le32(&cmd->cmd_dep, 0x02000000); cmd++; st_le16(&cmd->req_count, SAMPLE_COUNT * 4); st_le16(&cmd->command, OUTPUT_MORE); st_le32(&cmd->phy_addr, rm->dma_buf_p + offsetof(struct rackmeter_dma, buf1)); cmd++; st_le16(&cmd->req_count, 4); st_le16(&cmd->command, STORE_WORD | INTR_ALWAYS | KEY_SYSTEM); st_le32(&cmd->phy_addr, rm->dma_buf_p + offsetof(struct rackmeter_dma, mark)); st_le32(&cmd->cmd_dep, 0x01000000); cmd++; st_le16(&cmd->req_count, SAMPLE_COUNT * 4); st_le16(&cmd->command, OUTPUT_MORE | BR_ALWAYS); st_le32(&cmd->phy_addr, rm->dma_buf_p + offsetof(struct rackmeter_dma, buf2)); st_le32(&cmd->cmd_dep, rm->dma_buf_p); rackmeter_do_pause(rm, 0); } static void rackmeter_do_timer(struct work_struct *work) { struct rackmeter_cpu *rcpu = container_of(work, struct rackmeter_cpu, sniffer.work); struct rackmeter *rm = rcpu->rm; unsigned int cpu = smp_processor_id(); cputime64_t cur_jiffies, total_idle_ticks; unsigned int total_ticks, idle_ticks; int i, offset, load, cumm, pause; cur_jiffies = jiffies64_to_cputime64(get_jiffies_64()); total_ticks = (unsigned int)cputime64_sub(cur_jiffies, rcpu->prev_wall); rcpu->prev_wall = cur_jiffies; total_idle_ticks = get_cpu_idle_time(cpu); idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks, rcpu->prev_idle); rcpu->prev_idle = total_idle_ticks; /* We do a very dumb calculation to update the LEDs for now, * we'll do better once we have actual PWM implemented */ load = (9 * (total_ticks - idle_ticks)) / total_ticks; offset = cpu << 3; cumm = 0; for (i = 0; i < 8; i++) { u8 ub = (load > i) ? 0xff : 0; rm->ubuf[i + offset] = ub; cumm |= ub; } rcpu->zero = (cumm == 0); /* Now check if LEDs are all 0, we can stop DMA */ pause = (rm->cpu[0].zero && rm->cpu[1].zero); if (pause != rm->paused) { mutex_lock(&rm->sem); pause = (rm->cpu[0].zero && rm->cpu[1].zero); rackmeter_do_pause(rm, pause); mutex_unlock(&rm->sem); } schedule_delayed_work_on(cpu, &rcpu->sniffer, msecs_to_jiffies(CPU_SAMPLING_RATE)); } static void __devinit rackmeter_init_cpu_sniffer(struct rackmeter *rm) { unsigned int cpu; /* This driver works only with 1 or 2 CPUs numbered 0 and 1, * but that's really all we have on Apple Xserve. It doesn't * play very nice with CPU hotplug neither but we don't do that * on those machines yet */ rm->cpu[0].rm = rm; INIT_DELAYED_WORK(&rm->cpu[0].sniffer, rackmeter_do_timer); rm->cpu[1].rm = rm; INIT_DELAYED_WORK(&rm->cpu[1].sniffer, rackmeter_do_timer); for_each_online_cpu(cpu) { struct rackmeter_cpu *rcpu; if (cpu > 1) continue; rcpu = &rm->cpu[cpu];; rcpu->prev_idle = get_cpu_idle_time(cpu); rcpu->prev_wall = jiffies64_to_cputime64(get_jiffies_64()); schedule_delayed_work_on(cpu, &rm->cpu[cpu].sniffer, msecs_to_jiffies(CPU_SAMPLING_RATE)); } } static void __devexit rackmeter_stop_cpu_sniffer(struct rackmeter *rm) { cancel_rearming_delayed_work(&rm->cpu[0].sniffer); cancel_rearming_delayed_work(&rm->cpu[1].sniffer); } static int __devinit rackmeter_setup(struct rackmeter *rm) { pr_debug("rackmeter: setting up i2s..\n"); rackmeter_setup_i2s(rm); pr_debug("rackmeter: setting up default pattern..\n"); rackmeter_set_default_pattern(rm); pr_debug("rackmeter: setting up dbdma..\n"); rackmeter_setup_dbdma(rm); pr_debug("rackmeter: start CPU measurements..\n"); rackmeter_init_cpu_sniffer(rm); printk(KERN_INFO "RackMeter initialized\n"); return 0; } /* XXX FIXME: No PWM yet, this is 0/1 */ static u32 rackmeter_calc_sample(struct rackmeter *rm, unsigned int index) { int led; u32 sample = 0; for (led = 0; led < 16; led++) { sample >>= 1; sample |= ((rm->ubuf[led] >= 0x80) << 15); } return (sample << 17) | (sample >> 15); } static irqreturn_t rackmeter_irq(int irq, void *arg) { struct rackmeter *rm = arg; struct rackmeter_dma *db = rm->dma_buf_v; unsigned int mark, i; u32 *buf; /* Flush PCI buffers with an MMIO read. Maybe we could actually * check the status one day ... in case things go wrong, though * this never happened to me */ (void)in_le32(&rm->dma_regs->status); /* Make sure the CPU gets us in order */ rmb(); /* Read mark */ mark = db->mark; if (mark != 1 && mark != 2) { printk(KERN_WARNING "rackmeter: Incorrect DMA mark 0x%08x\n", mark); /* We allow for 3 errors like that (stale DBDMA irqs) */ if (++rm->stale_irq > 3) { printk(KERN_ERR "rackmeter: Too many errors," " stopping DMA\n"); DBDMA_DO_RESET(rm->dma_regs); } return IRQ_HANDLED; } /* Next buffer we need to fill is mark value */ buf = mark == 1 ? db->buf1 : db->buf2; /* Fill it now. This routine converts the 8 bits depth sample array * into the PWM bitmap for each LED. */ for (i = 0; i < SAMPLE_COUNT; i++) buf[i] = rackmeter_calc_sample(rm, i); return IRQ_HANDLED; } static int __devinit rackmeter_probe(struct macio_dev* mdev, const struct of_device_id *match) { struct device_node *i2s = NULL, *np = NULL; struct rackmeter *rm = NULL; struct resource ri2s, rdma; int rc = -ENODEV; pr_debug("rackmeter_probe()\n"); /* Get i2s-a node */ while ((i2s = of_get_next_child(mdev->ofdev.node, i2s)) != NULL) if (strcmp(i2s->name, "i2s-a") == 0) break; if (i2s == NULL) { pr_debug(" i2s-a child not found\n"); goto bail; } /* Get lightshow or virtual sound */ while ((np = of_get_next_child(i2s, np)) != NULL) { if (strcmp(np->name, "lightshow") == 0) break; if ((strcmp(np->name, "sound") == 0) && of_get_property(np, "virtual", NULL) != NULL) break; } if (np == NULL) { pr_debug(" lightshow or sound+virtual child not found\n"); goto bail; } /* Create and initialize our instance data */ rm = kzalloc(sizeof(struct rackmeter), GFP_KERNEL); if (rm == NULL) { printk(KERN_ERR "rackmeter: failed to allocate memory !\n"); rc = -ENOMEM; goto bail_release; } rm->mdev = mdev; rm->i2s = i2s; mutex_init(&rm->sem); dev_set_drvdata(&mdev->ofdev.dev, rm); /* Check resources availability. We need at least resource 0 and 1 */ #if 0 /* Use that when i2s-a is finally an mdev per-se */ if (macio_resource_count(mdev) < 2 || macio_irq_count(mdev) < 2) { printk(KERN_ERR "rackmeter: found match but lacks resources: %s" " (%d resources, %d interrupts)\n", mdev->ofdev.node->full_name); rc = -ENXIO; goto bail_free; } if (macio_request_resources(mdev, "rackmeter")) { printk(KERN_ERR "rackmeter: failed to request resources: %s\n", mdev->ofdev.node->full_name); rc = -EBUSY; goto bail_free; } rm->irq = macio_irq(mdev, 1); #else rm->irq = irq_of_parse_and_map(i2s, 1); if (rm->irq == NO_IRQ || of_address_to_resource(i2s, 0, &ri2s) || of_address_to_resource(i2s, 1, &rdma)) { printk(KERN_ERR "rackmeter: found match but lacks resources: %s", mdev->ofdev.node->full_name); rc = -ENXIO; goto bail_free; } #endif pr_debug(" i2s @0x%08x\n", (unsigned int)ri2s.start); pr_debug(" dma @0x%08x\n", (unsigned int)rdma.start); pr_debug(" irq %d\n", rm->irq); rm->ubuf = (u8 *)__get_free_page(GFP_KERNEL); if (rm->ubuf == NULL) { printk(KERN_ERR "rackmeter: failed to allocate samples page !\n"); rc = -ENOMEM; goto bail_release; } rm->dma_buf_v = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev, sizeof(struct rackmeter_dma), &rm->dma_buf_p, GFP_KERNEL); if (rm->dma_buf_v == NULL) { printk(KERN_ERR "rackmeter: failed to allocate dma buffer !\n"); rc = -ENOMEM; goto bail_free_samples; } #if 0 rm->i2s_regs = ioremap(macio_resource_start(mdev, 0), 0x1000); #else rm->i2s_regs = ioremap(ri2s.start, 0x1000); #endif if (rm->i2s_regs == NULL) { printk(KERN_ERR "rackmeter: failed to map i2s registers !\n"); rc = -ENXIO; goto bail_free_dma; } #if 0 rm->dma_regs = ioremap(macio_resource_start(mdev, 1), 0x100); #else rm->dma_regs = ioremap(rdma.start, 0x100); #endif if (rm->dma_regs == NULL) { printk(KERN_ERR "rackmeter: failed to map dma registers !\n"); rc = -ENXIO; goto bail_unmap_i2s; } rc = rackmeter_setup(rm); if (rc) { printk(KERN_ERR "rackmeter: failed to initialize !\n"); rc = -ENXIO; goto bail_unmap_dma; } rc = request_irq(rm->irq, rackmeter_irq, 0, "rackmeter", rm); if (rc != 0) { printk(KERN_ERR "rackmeter: failed to request interrupt !\n"); goto bail_stop_dma; } of_node_put(np); return 0; bail_stop_dma: DBDMA_DO_RESET(rm->dma_regs); bail_unmap_dma: iounmap(rm->dma_regs); bail_unmap_i2s: iounmap(rm->i2s_regs); bail_free_dma: dma_free_coherent(&macio_get_pci_dev(mdev)->dev, sizeof(struct rackmeter_dma), rm->dma_buf_v, rm->dma_buf_p); bail_free_samples: free_page((unsigned long)rm->ubuf); bail_release: #if 0 macio_release_resources(mdev); #endif bail_free: kfree(rm); bail: of_node_put(i2s); of_node_put(np); dev_set_drvdata(&mdev->ofdev.dev, NULL); return rc; } static int __devexit rackmeter_remove(struct macio_dev* mdev) { struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev); /* Stop CPU sniffer timer & work queues */ rackmeter_stop_cpu_sniffer(rm); /* Clear reference to private data */ dev_set_drvdata(&mdev->ofdev.dev, NULL); /* Stop/reset dbdma */ DBDMA_DO_RESET(rm->dma_regs); /* Release the IRQ */ free_irq(rm->irq, rm); /* Unmap registers */ iounmap(rm->dma_regs); iounmap(rm->i2s_regs); /* Free DMA */ dma_free_coherent(&macio_get_pci_dev(mdev)->dev, sizeof(struct rackmeter_dma), rm->dma_buf_v, rm->dma_buf_p); /* Free samples */ free_page((unsigned long)rm->ubuf); #if 0 /* Release resources */ macio_release_resources(mdev); #endif /* Get rid of me */ kfree(rm); return 0; } static int rackmeter_shutdown(struct macio_dev* mdev) { struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev); if (rm == NULL) return -ENODEV; /* Stop CPU sniffer timer & work queues */ rackmeter_stop_cpu_sniffer(rm); /* Stop/reset dbdma */ DBDMA_DO_RESET(rm->dma_regs); return 0; } static struct of_device_id rackmeter_match[] = { { .name = "i2s" }, { } }; static struct macio_driver rackmeter_driver = { .name = "rackmeter", .owner = THIS_MODULE, .match_table = rackmeter_match, .probe = rackmeter_probe, .remove = __devexit_p(rackmeter_remove), .shutdown = rackmeter_shutdown, }; static int __init rackmeter_init(void) { pr_debug("rackmeter_init()\n"); return macio_register_driver(&rackmeter_driver); } static void __exit rackmeter_exit(void) { pr_debug("rackmeter_exit()\n"); macio_unregister_driver(&rackmeter_driver); } module_init(rackmeter_init); module_exit(rackmeter_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel");