[net-next-2.6.git] / drivers / macintosh / rack-meter.c

/*
 * 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 <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");
Commit	Line	Data
3e00a5ae BH	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>
5a0e3ad6	21	#include <linux/slab.h>
3e00a5ae BH	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
	29	#include <asm/io.h>
	30	#include <asm/prom.h>
	31	#include <asm/machdep.h>
	32	#include <asm/pmac_feature.h>
	33	#include <asm/dbdma.h>
3e00a5ae BH	34	#include <asm/macio.h>
	35	#include <asm/keylargo.h>
	36
	37	/* Number of samples in a sample buffer */
	38	#define SAMPLE_COUNT 256
	39
	40	/* CPU meter sampling rate in ms */
	41	#define CPU_SAMPLING_RATE 250
	42
	43	struct rackmeter_dma {
	44	struct dbdma_cmd cmd[4] ____cacheline_aligned;
	45	u32 mark ____cacheline_aligned;
	46	u32 buf1[SAMPLE_COUNT] ____cacheline_aligned;
	47	u32 buf2[SAMPLE_COUNT] ____cacheline_aligned;
	48	} ____cacheline_aligned;
	49
	50	struct rackmeter_cpu {
6d5aefb8 DH	51	struct delayed_work sniffer;
6d5aefb8 DH	52	struct rackmeter *rm;
3e00a5ae BH	53	cputime64_t prev_wall;
	54	cputime64_t prev_idle;
	55	int zero;
	56	} ____cacheline_aligned;
	57
	58	struct rackmeter {
	59	struct macio_dev *mdev;
	60	unsigned int irq;
	61	struct device_node *i2s;
	62	u8 *ubuf;
	63	struct dbdma_regs __iomem *dma_regs;
	64	void __iomem *i2s_regs;
	65	dma_addr_t dma_buf_p;
	66	struct rackmeter_dma *dma_buf_v;
	67	int stale_irq;
	68	struct rackmeter_cpu cpu[2];
	69	int paused;
	70	struct mutex sem;
	71	};
	72
	73	/* To be set as a tunable */
	74	static int rackmeter_ignore_nice;
	75
	76	/* This GPIO is whacked by the OS X driver when initializing */
	77	#define RACKMETER_MAGIC_GPIO 0x78
	78
	79	/* This is copied from cpufreq_ondemand, maybe we should put it in
	80	* a common header somewhere
	81	*/
	82	static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
	83	{
	84	cputime64_t retval;
	85
	86	retval = cputime64_add(kstat_cpu(cpu).cpustat.idle,
	87	kstat_cpu(cpu).cpustat.iowait);
	88
	89	if (rackmeter_ignore_nice)
	90	retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice);
	91
	92	return retval;
	93	}
	94
	95	static void rackmeter_setup_i2s(struct rackmeter *rm)
	96	{
	97	struct macio_chip *macio = rm->mdev->bus->chip;
	98
	99	/* First whack magic GPIO */
	100	pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, RACKMETER_MAGIC_GPIO, 5);
	101
	102
	103	/* Call feature code to enable the sound channel and the proper
	104	* clock sources
	105	*/
	106	pmac_call_feature(PMAC_FTR_SOUND_CHIP_ENABLE, rm->i2s, 0, 1);
	107
	108	/* Power i2s and stop i2s clock. We whack MacIO FCRs directly for now.
	109	* This is a bit racy, thus we should add new platform functions to
	110	* handle that. snd-aoa needs that too
	111	*/
	112	MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_ENABLE);
	113	MACIO_BIC(KEYLARGO_FCR1, KL1_I2S0_CLK_ENABLE_BIT);
	114	(void)MACIO_IN32(KEYLARGO_FCR1);
	115	udelay(10);
	116
117	/* Then setup i2s. For now, we use the same magic value that
118	* the OS X driver seems to use. We might want to play around
119	* with the clock divisors later
120	*/
121	out_le32(rm->i2s_regs + 0x10, 0x01fa0000);
122	(void)in_le32(rm->i2s_regs + 0x10);
123	udelay(10);
124
125	/* Fully restart i2s*/
126	MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_CELL_ENABLE \|
127	KL1_I2S0_CLK_ENABLE_BIT);
128	(void)MACIO_IN32(KEYLARGO_FCR1);
129	udelay(10);
130	}
131
132	static void rackmeter_set_default_pattern(struct rackmeter *rm)
133	{
134	int i;
135
136	for (i = 0; i < 16; i++) {
137	if (i < 8)
138	rm->ubuf[i] = (i & 1) * 255;
139	else
140	rm->ubuf[i] = ((~i) & 1) * 255;
141	}
142	}
143
144	static void rackmeter_do_pause(struct rackmeter *rm, int pause)
145	{
146	struct rackmeter_dma *rdma = rm->dma_buf_v;
147
148	pr_debug("rackmeter: %s\n", pause ? "paused" : "started");
149
150	rm->paused = pause;
151	if (pause) {
152	DBDMA_DO_STOP(rm->dma_regs);
153	return;
154	}
155	memset(rdma->buf1, 0, SAMPLE_COUNT & sizeof(u32));
156	memset(rdma->buf2, 0, SAMPLE_COUNT & sizeof(u32));
157
158	rm->dma_buf_v->mark = 0;
159
160	mb();
161	out_le32(&rm->dma_regs->cmdptr_hi, 0);
162	out_le32(&rm->dma_regs->cmdptr, rm->dma_buf_p);
163	out_le32(&rm->dma_regs->control, (RUN << 16) \| RUN);
164	}
165
166	static void rackmeter_setup_dbdma(struct rackmeter *rm)
167	{
168	struct rackmeter_dma *db = rm->dma_buf_v;
169	struct dbdma_cmd *cmd = db->cmd;
170
171	/* Make sure dbdma is reset */
172	DBDMA_DO_RESET(rm->dma_regs);
173
193d0732	174	pr_debug("rackmeter: mark offset=0x%zx\n",
3e00a5ae	175	offsetof(struct rackmeter_dma, mark));
193d0732	176	pr_debug("rackmeter: buf1 offset=0x%zx\n",
3e00a5ae	177	offsetof(struct rackmeter_dma, buf1));
193d0732	178	pr_debug("rackmeter: buf2 offset=0x%zx\n",
3e00a5ae BH	179	offsetof(struct rackmeter_dma, buf2));
	180
	181	/* Prepare 4 dbdma commands for the 2 buffers */
	182	memset(cmd, 0, 4 * sizeof(struct dbdma_cmd));
	183	st_le16(&cmd->req_count, 4);
	184	st_le16(&cmd->command, STORE_WORD \| INTR_ALWAYS \| KEY_SYSTEM);
	185	st_le32(&cmd->phy_addr, rm->dma_buf_p +
	186	offsetof(struct rackmeter_dma, mark));
	187	st_le32(&cmd->cmd_dep, 0x02000000);
	188	cmd++;
	189
	190	st_le16(&cmd->req_count, SAMPLE_COUNT * 4);
	191	st_le16(&cmd->command, OUTPUT_MORE);
	192	st_le32(&cmd->phy_addr, rm->dma_buf_p +
	193	offsetof(struct rackmeter_dma, buf1));
	194	cmd++;
	195
	196	st_le16(&cmd->req_count, 4);
	197	st_le16(&cmd->command, STORE_WORD \| INTR_ALWAYS \| KEY_SYSTEM);
	198	st_le32(&cmd->phy_addr, rm->dma_buf_p +
	199	offsetof(struct rackmeter_dma, mark));
	200	st_le32(&cmd->cmd_dep, 0x01000000);
	201	cmd++;
	202
	203	st_le16(&cmd->req_count, SAMPLE_COUNT * 4);
	204	st_le16(&cmd->command, OUTPUT_MORE \| BR_ALWAYS);
	205	st_le32(&cmd->phy_addr, rm->dma_buf_p +
	206	offsetof(struct rackmeter_dma, buf2));
	207	st_le32(&cmd->cmd_dep, rm->dma_buf_p);
	208
	209	rackmeter_do_pause(rm, 0);
	210	}
	211
6d5aefb8	212	static void rackmeter_do_timer(struct work_struct *work)
3e00a5ae	213	{
6d5aefb8 DH	214	struct rackmeter_cpu *rcpu =
	215	container_of(work, struct rackmeter_cpu, sniffer.work);
	216	struct rackmeter *rm = rcpu->rm;
3e00a5ae	217	unsigned int cpu = smp_processor_id();
3e00a5ae BH	218	cputime64_t cur_jiffies, total_idle_ticks;
	219	unsigned int total_ticks, idle_ticks;
	220	int i, offset, load, cumm, pause;
	221
	222	cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
	223	total_ticks = (unsigned int)cputime64_sub(cur_jiffies,
	224	rcpu->prev_wall);
	225	rcpu->prev_wall = cur_jiffies;
	226
	227	total_idle_ticks = get_cpu_idle_time(cpu);
	228	idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks,
	229	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 __devinit 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
6d5aefb8 DH	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);
3e00a5ae BH	272
	273	for_each_online_cpu(cpu) {
	274	struct rackmeter_cpu *rcpu;
	275
	276	if (cpu > 1)
	277	continue;
a419aef8	278	rcpu = &rm->cpu[cpu];
3e00a5ae BH	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 __devexit rackmeter_stop_cpu_sniffer(struct rackmeter *rm)
	287	{
	288	cancel_rearming_delayed_work(&rm->cpu[0].sniffer);
	289	cancel_rearming_delayed_work(&rm->cpu[1].sniffer);
	290	}
	291
31421a6f	292	static int __devinit rackmeter_setup(struct rackmeter *rm)
3e00a5ae BH	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 __devinit 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.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) &&
01b2726d	390	of_get_property(np, "virtual", NULL) != NULL)
3e00a5ae BH	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.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 __devexit 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
31421a6f	586	static struct macio_driver rackmeter_driver = {
3e00a5ae BH	587	.name = "rackmeter",
	588	.owner = THIS_MODULE,
	589	.match_table = rackmeter_match,
	590	.probe = rackmeter_probe,
31421a6f	591	.remove = __devexit_p(rackmeter_remove),
3e00a5ae BH	592	.shutdown = rackmeter_shutdown,
	593	};
	594
	595
	596	static int __init rackmeter_init(void)
	597	{
	598	pr_debug("rackmeter_init()\n");
	599
31421a6f	600	return macio_register_driver(&rackmeter_driver);
3e00a5ae BH	601	}
	602
	603	static void __exit rackmeter_exit(void)
	604	{
	605	pr_debug("rackmeter_exit()\n");
	606
31421a6f	607	macio_unregister_driver(&rackmeter_driver);
3e00a5ae BH	608	}
	609
	610	module_init(rackmeter_init);
	611	module_exit(rackmeter_exit);
	612
	613
	614	MODULE_LICENSE("GPL");
	615	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	616	MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel");