[linux-2.6-block.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 <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" },
	{ }
};
MODULE_DEVICE_TABLE(of, rackmeter_match);

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");
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>
5af50730 RH	28	#include <linux/of_address.h>
5af50730 RH	29	#include <linux/of_irq.h>
3e00a5ae BH	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>
3e00a5ae BH	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 {
6d5aefb8 DH	53	struct delayed_work sniffer;
6d5aefb8 DH	54	struct rackmeter *rm;
3e00a5ae BH	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	{
3292beb3	86	u64 retval;
3e00a5ae	87
3292beb3 GC	88	retval = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE] +
3292beb3 GC	89	kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
3e00a5ae BH	90
3e00a5ae BH	91	if (rackmeter_ignore_nice)
3292beb3	92	retval += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
3e00a5ae BH	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, SAMPLE_COUNT & sizeof(u32));
158	memset(rdma->buf2, 0, SAMPLE_COUNT & sizeof(u32));
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
193d0732	176	pr_debug("rackmeter: mark offset=0x%zx\n",
3e00a5ae	177	offsetof(struct rackmeter_dma, mark));
193d0732	178	pr_debug("rackmeter: buf1 offset=0x%zx\n",
3e00a5ae	179	offsetof(struct rackmeter_dma, buf1));
193d0732	180	pr_debug("rackmeter: buf2 offset=0x%zx\n",
3e00a5ae BH	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));
f5718726 DG	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 +
3e00a5ae	188	offsetof(struct rackmeter_dma, mark));
f5718726	189	cmd->cmd_dep = cpu_to_le32(0x02000000);
3e00a5ae BH	190	cmd++;
3e00a5ae BH	191
f5718726 DG	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 +
3e00a5ae BH	195	offsetof(struct rackmeter_dma, buf1));
	196	cmd++;
	197
f5718726 DG	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 +
3e00a5ae	201	offsetof(struct rackmeter_dma, mark));
f5718726	202	cmd->cmd_dep = cpu_to_le32(0x01000000);
3e00a5ae BH	203	cmd++;
3e00a5ae BH	204
f5718726 DG	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 +
3e00a5ae	208	offsetof(struct rackmeter_dma, buf2));
f5718726	209	cmd->cmd_dep = cpu_to_le32(rm->dma_buf_p);
3e00a5ae BH	210
	211	rackmeter_do_pause(rm, 0);
	212	}
	213
6d5aefb8	214	static void rackmeter_do_timer(struct work_struct *work)
3e00a5ae	215	{
6d5aefb8 DH	216	struct rackmeter_cpu *rcpu =
	217	container_of(work, struct rackmeter_cpu, sniffer.work);
	218	struct rackmeter *rm = rcpu->rm;
3e00a5ae	219	unsigned int cpu = smp_processor_id();
3e00a5ae BH	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());
64861634	225	total_ticks = (unsigned int) (cur_jiffies - rcpu->prev_wall);
3e00a5ae BH	226	rcpu->prev_wall = cur_jiffies;
	227
	228	total_idle_ticks = get_cpu_idle_time(cpu);
64861634	229	idle_ticks = (unsigned int) (total_idle_ticks - rcpu->prev_idle);
3e00a5ae BH	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
1da42fb6	258	static void rackmeter_init_cpu_sniffer(struct rackmeter *rm)
3e00a5ae BH	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
e1f4dea4	286	static void rackmeter_stop_cpu_sniffer(struct rackmeter *rm)
3e00a5ae	287	{
afe2c511 TH	288	cancel_delayed_work_sync(&rm->cpu[0].sniffer);
afe2c511 TH	289	cancel_delayed_work_sync(&rm->cpu[1].sniffer);
3e00a5ae BH	290	}
3e00a5ae BH	291
1da42fb6	292	static int 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
1da42fb6 GKH	367	static int rackmeter_probe(struct macio_dev* mdev,
1da42fb6 GKH	368	const struct of_device_id *match)
3e00a5ae BH	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 */
61c7a080	378	while ((i2s = of_get_next_child(mdev->ofdev.dev.of_node, i2s)) != NULL)
3e00a5ae BH	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",
61c7a080	434	mdev->ofdev.dev.of_node->full_name);
3e00a5ae BH	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
1da42fb6	526	static int rackmeter_remove(struct macio_dev* mdev)
3e00a5ae BH	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	};
6735b2e9	585	MODULE_DEVICE_TABLE(of, rackmeter_match);
3e00a5ae	586
31421a6f	587	static struct macio_driver rackmeter_driver = {
c2cdf6ab BH	588	.driver = {
	589	.name = "rackmeter",
	590	.owner = THIS_MODULE,
	591	.of_match_table = rackmeter_match,
	592	},
3e00a5ae	593	.probe = rackmeter_probe,
1da42fb6	594	.remove = rackmeter_remove,
3e00a5ae BH	595	.shutdown = rackmeter_shutdown,
	596	};
	597
	598
	599	static int __init rackmeter_init(void)
	600	{
	601	pr_debug("rackmeter_init()\n");
	602
31421a6f	603	return macio_register_driver(&rackmeter_driver);
3e00a5ae BH	604	}
	605
	606	static void __exit rackmeter_exit(void)
	607	{
	608	pr_debug("rackmeter_exit()\n");
	609
31421a6f	610	macio_unregister_driver(&rackmeter_driver);
3e00a5ae BH	611	}
	612
	613	module_init(rackmeter_init);
	614	module_exit(rackmeter_exit);
	615
	616
	617	MODULE_LICENSE("GPL");
	618	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	619	MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel");