diff options
Diffstat (limited to 'drivers/macintosh/rack-meter.c')
| -rw-r--r-- | drivers/macintosh/rack-meter.c | 618 |
1 files changed, 618 insertions, 0 deletions
diff --git a/drivers/macintosh/rack-meter.c b/drivers/macintosh/rack-meter.c new file mode 100644 index 000000000..048901a11 --- /dev/null +++ b/drivers/macintosh/rack-meter.c @@ -0,0 +1,618 @@ +/* + * 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/slab.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 <linux/of_address.h> +#include <linux/of_irq.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) +{ + u64 retval; + + retval = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE] + + kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT]; + + if (rackmeter_ignore_nice) + retval += kcpustat_cpu(cpu).cpustat[CPUTIME_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)); + cmd->req_count = cpu_to_le16(4); + cmd->command = cpu_to_le16(STORE_WORD | INTR_ALWAYS | KEY_SYSTEM); + cmd->phy_addr = cpu_to_le32(rm->dma_buf_p + + offsetof(struct rackmeter_dma, mark)); + cmd->cmd_dep = cpu_to_le32(0x02000000); + cmd++; + + cmd->req_count = cpu_to_le16(SAMPLE_COUNT * 4); + cmd->command = cpu_to_le16(OUTPUT_MORE); + cmd->phy_addr = cpu_to_le32(rm->dma_buf_p + + offsetof(struct rackmeter_dma, buf1)); + cmd++; + + cmd->req_count = cpu_to_le16(4); + cmd->command = cpu_to_le16(STORE_WORD | INTR_ALWAYS | KEY_SYSTEM); + cmd->phy_addr = cpu_to_le32(rm->dma_buf_p + + offsetof(struct rackmeter_dma, mark)); + cmd->cmd_dep = cpu_to_le32(0x01000000); + cmd++; + + cmd->req_count = cpu_to_le16(SAMPLE_COUNT * 4); + cmd->command = cpu_to_le16(OUTPUT_MORE | BR_ALWAYS); + cmd->phy_addr = cpu_to_le32(rm->dma_buf_p + + offsetof(struct rackmeter_dma, buf2)); + cmd->cmd_dep = cpu_to_le32(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) (cur_jiffies - rcpu->prev_wall); + rcpu->prev_wall = cur_jiffies; + + total_idle_ticks = get_cpu_idle_time(cpu); + idle_ticks = (unsigned int) (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 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 rackmeter_stop_cpu_sniffer(struct rackmeter *rm) +{ + cancel_delayed_work_sync(&rm->cpu[0].sniffer); + cancel_delayed_work_sync(&rm->cpu[1].sniffer); +} + +static int 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 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.dev.of_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.dev.of_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 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 = { + .driver = { + .name = "rackmeter", + .owner = THIS_MODULE, + .of_match_table = rackmeter_match, + }, + .probe = rackmeter_probe, + .remove = 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"); |