--- /dev/null
+/*
+ * 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/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 work_struct sniffer;
+ 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%lx\n",
+ offsetof(struct rackmeter_dma, mark));
+ pr_debug("rackmeter: buf1 offset=0x%lx\n",
+ offsetof(struct rackmeter_dma, buf1));
+ pr_debug("rackmeter: buf2 offset=0x%lx\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(void *data)
+{
+ struct rackmeter *rm = data;
+ unsigned int cpu = smp_processor_id();
+ struct rackmeter_cpu *rcpu = &rm->cpu[cpu];
+ 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
+ */
+
+ INIT_WORK(&rm->cpu[0].sniffer, rackmeter_do_timer, rm);
+ INIT_WORK(&rm->cpu[1].sniffer, rackmeter_do_timer, rm);
+
+ 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 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) &&
+ 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_drv = {
+ .name = "rackmeter",
+ .owner = THIS_MODULE,
+ .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_drv);
+}
+
+static void __exit rackmeter_exit(void)
+{
+ pr_debug("rackmeter_exit()\n");
+
+ macio_unregister_driver(&rackmeter_drv);
+}
+
+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");
projects / linux-2.6-omap-h63xx.git / commitdiff