[deliverable/linux.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/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");
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>
	21	#include <linux/device.h>
	22	#include <linux/interrupt.h>
	23	#include <linux/module.h>
	24	#include <linux/pci.h>
	25	#include <linux/dma-mapping.h>
	26	#include <linux/kernel_stat.h>
	27
	28	#include <asm/io.h>
	29	#include <asm/prom.h>
	30	#include <asm/machdep.h>
	31	#include <asm/pmac_feature.h>
	32	#include <asm/dbdma.h>
	33	#include <asm/dbdma.h>
	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 {
	51	struct work_struct sniffer;
	52	cputime64_t prev_wall;
	53	cputime64_t prev_idle;
	54	int zero;
	55	} ____cacheline_aligned;
	56
	57	struct rackmeter {
	58	struct macio_dev *mdev;
	59	unsigned int irq;
	60	struct device_node *i2s;
	61	u8 *ubuf;
	62	struct dbdma_regs __iomem *dma_regs;
	63	void __iomem *i2s_regs;
	64	dma_addr_t dma_buf_p;
65	struct rackmeter_dma *dma_buf_v;
66	int stale_irq;
67	struct rackmeter_cpu cpu[2];
68	int paused;
69	struct mutex sem;
70	};
71
72	/* To be set as a tunable */
73	static int rackmeter_ignore_nice;
74
75	/* This GPIO is whacked by the OS X driver when initializing */
76	#define RACKMETER_MAGIC_GPIO 0x78
77
78	/* This is copied from cpufreq_ondemand, maybe we should put it in
79	* a common header somewhere
80	*/
81	static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
82	{
83	cputime64_t retval;
84
85	retval = cputime64_add(kstat_cpu(cpu).cpustat.idle,
86	kstat_cpu(cpu).cpustat.iowait);
87
88	if (rackmeter_ignore_nice)
89	retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice);
90
91	return retval;
92	}
93
94	static void rackmeter_setup_i2s(struct rackmeter *rm)
95	{
96	struct macio_chip *macio = rm->mdev->bus->chip;
97
98	/* First whack magic GPIO */
99	pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, RACKMETER_MAGIC_GPIO, 5);
100
101
102	/* Call feature code to enable the sound channel and the proper
103	* clock sources
104	*/
105	pmac_call_feature(PMAC_FTR_SOUND_CHIP_ENABLE, rm->i2s, 0, 1);
106
107	/* Power i2s and stop i2s clock. We whack MacIO FCRs directly for now.
108	* This is a bit racy, thus we should add new platform functions to
109	* handle that. snd-aoa needs that too
110	*/
111	MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_ENABLE);
112	MACIO_BIC(KEYLARGO_FCR1, KL1_I2S0_CLK_ENABLE_BIT);
113	(void)MACIO_IN32(KEYLARGO_FCR1);
114	udelay(10);
115
116	/* Then setup i2s. For now, we use the same magic value that
117	* the OS X driver seems to use. We might want to play around
118	* with the clock divisors later
119	*/
120	out_le32(rm->i2s_regs + 0x10, 0x01fa0000);
121	(void)in_le32(rm->i2s_regs + 0x10);
122	udelay(10);
123
124	/* Fully restart i2s*/
125	MACIO_BIS(KEYLARGO_FCR1, KL1_I2S0_CELL_ENABLE \|
126	KL1_I2S0_CLK_ENABLE_BIT);
127	(void)MACIO_IN32(KEYLARGO_FCR1);
128	udelay(10);
129	}
130
131	static void rackmeter_set_default_pattern(struct rackmeter *rm)
132	{
133	int i;
134
135	for (i = 0; i < 16; i++) {
136	if (i < 8)
137	rm->ubuf[i] = (i & 1) * 255;
138	else
139	rm->ubuf[i] = ((~i) & 1) * 255;
140	}
141	}
142
143	static void rackmeter_do_pause(struct rackmeter *rm, int pause)
144	{
145	struct rackmeter_dma *rdma = rm->dma_buf_v;
146
147	pr_debug("rackmeter: %s\n", pause ? "paused" : "started");
148
149	rm->paused = pause;
150	if (pause) {
151	DBDMA_DO_STOP(rm->dma_regs);
152	return;
153	}
154	memset(rdma->buf1, 0, SAMPLE_COUNT & sizeof(u32));
155	memset(rdma->buf2, 0, SAMPLE_COUNT & sizeof(u32));
156
157	rm->dma_buf_v->mark = 0;
158
159	mb();
160	out_le32(&rm->dma_regs->cmdptr_hi, 0);
161	out_le32(&rm->dma_regs->cmdptr, rm->dma_buf_p);
162	out_le32(&rm->dma_regs->control, (RUN << 16) \| RUN);
163	}
164
165	static void rackmeter_setup_dbdma(struct rackmeter *rm)
166	{
167	struct rackmeter_dma *db = rm->dma_buf_v;
168	struct dbdma_cmd *cmd = db->cmd;
169
170	/* Make sure dbdma is reset */
171	DBDMA_DO_RESET(rm->dma_regs);
172
173	pr_debug("rackmeter: mark offset=0x%lx\n",
174	offsetof(struct rackmeter_dma, mark));
175	pr_debug("rackmeter: buf1 offset=0x%lx\n",
176	offsetof(struct rackmeter_dma, buf1));
177	pr_debug("rackmeter: buf2 offset=0x%lx\n",
178	offsetof(struct rackmeter_dma, buf2));
179
180	/* Prepare 4 dbdma commands for the 2 buffers */
181	memset(cmd, 0, 4 * sizeof(struct dbdma_cmd));
182	st_le16(&cmd->req_count, 4);
183	st_le16(&cmd->command, STORE_WORD \| INTR_ALWAYS \| KEY_SYSTEM);
184	st_le32(&cmd->phy_addr, rm->dma_buf_p +
185	offsetof(struct rackmeter_dma, mark));
186	st_le32(&cmd->cmd_dep, 0x02000000);
187	cmd++;
188
189	st_le16(&cmd->req_count, SAMPLE_COUNT * 4);
190	st_le16(&cmd->command, OUTPUT_MORE);
191	st_le32(&cmd->phy_addr, rm->dma_buf_p +
192	offsetof(struct rackmeter_dma, buf1));
193	cmd++;
194
195	st_le16(&cmd->req_count, 4);
196	st_le16(&cmd->command, STORE_WORD \| INTR_ALWAYS \| KEY_SYSTEM);
197	st_le32(&cmd->phy_addr, rm->dma_buf_p +
198	offsetof(struct rackmeter_dma, mark));
199	st_le32(&cmd->cmd_dep, 0x01000000);
200	cmd++;
201
202	st_le16(&cmd->req_count, SAMPLE_COUNT * 4);
203	st_le16(&cmd->command, OUTPUT_MORE \| BR_ALWAYS);
204	st_le32(&cmd->phy_addr, rm->dma_buf_p +
205	offsetof(struct rackmeter_dma, buf2));
206	st_le32(&cmd->cmd_dep, rm->dma_buf_p);
207
208	rackmeter_do_pause(rm, 0);
209	}
210
211	static void rackmeter_do_timer(void *data)
212	{
213	struct rackmeter *rm = data;
214	unsigned int cpu = smp_processor_id();
215	struct rackmeter_cpu *rcpu = &rm->cpu[cpu];
216	cputime64_t cur_jiffies, total_idle_ticks;
217	unsigned int total_ticks, idle_ticks;
218	int i, offset, load, cumm, pause;
219
220	cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
221	total_ticks = (unsigned int)cputime64_sub(cur_jiffies,
222	rcpu->prev_wall);
223	rcpu->prev_wall = cur_jiffies;
224
225	total_idle_ticks = get_cpu_idle_time(cpu);
226	idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks,
227	rcpu->prev_idle);
228	rcpu->prev_idle = total_idle_ticks;
229
230	/* We do a very dumb calculation to update the LEDs for now,
231	* we'll do better once we have actual PWM implemented
232	*/
233	load = (9 * (total_ticks - idle_ticks)) / total_ticks;
234
235	offset = cpu << 3;
236	cumm = 0;
237	for (i = 0; i < 8; i++) {
238	u8 ub = (load > i) ? 0xff : 0;
239	rm->ubuf[i + offset] = ub;
240	cumm \|= ub;
241	}
242	rcpu->zero = (cumm == 0);
243
244	/* Now check if LEDs are all 0, we can stop DMA */
245	pause = (rm->cpu[0].zero && rm->cpu[1].zero);
246	if (pause != rm->paused) {
247	mutex_lock(&rm->sem);
248	pause = (rm->cpu[0].zero && rm->cpu[1].zero);
249	rackmeter_do_pause(rm, pause);
250	mutex_unlock(&rm->sem);
251	}
252	schedule_delayed_work_on(cpu, &rcpu->sniffer,
253	msecs_to_jiffies(CPU_SAMPLING_RATE));
254	}
255
256	static void __devinit rackmeter_init_cpu_sniffer(struct rackmeter *rm)
257	{
258	unsigned int cpu;
259
260	/* This driver works only with 1 or 2 CPUs numbered 0 and 1,
261	* but that's really all we have on Apple Xserve. It doesn't
262	* play very nice with CPU hotplug neither but we don't do that
263	* on those machines yet
264	*/
265
266	INIT_WORK(&rm->cpu[0].sniffer, rackmeter_do_timer, rm);
267	INIT_WORK(&rm->cpu[1].sniffer, rackmeter_do_timer, rm);
268
269	for_each_online_cpu(cpu) {
270	struct rackmeter_cpu *rcpu;
271
272	if (cpu > 1)
273	continue;
274	rcpu = &rm->cpu[cpu];;
275	rcpu->prev_idle = get_cpu_idle_time(cpu);
276	rcpu->prev_wall = jiffies64_to_cputime64(get_jiffies_64());
277	schedule_delayed_work_on(cpu, &rm->cpu[cpu].sniffer,
278	msecs_to_jiffies(CPU_SAMPLING_RATE));
279	}
280	}
281
282	static void __devexit rackmeter_stop_cpu_sniffer(struct rackmeter *rm)
283	{
284	cancel_rearming_delayed_work(&rm->cpu[0].sniffer);
285	cancel_rearming_delayed_work(&rm->cpu[1].sniffer);
286	}
287
288	static int rackmeter_setup(struct rackmeter *rm)
289	{
290	pr_debug("rackmeter: setting up i2s..\n");
291	rackmeter_setup_i2s(rm);
292
293	pr_debug("rackmeter: setting up default pattern..\n");
294	rackmeter_set_default_pattern(rm);
295
296	pr_debug("rackmeter: setting up dbdma..\n");
297	rackmeter_setup_dbdma(rm);
298
299	pr_debug("rackmeter: start CPU measurements..\n");
300	rackmeter_init_cpu_sniffer(rm);
301
302	printk(KERN_INFO "RackMeter initialized\n");
303
304	return 0;
305	}
306
307	/* XXX FIXME: No PWM yet, this is 0/1 */
308	static u32 rackmeter_calc_sample(struct rackmeter *rm, unsigned int index)
309	{
310	int led;
311	u32 sample = 0;
312
313	for (led = 0; led < 16; led++) {
314	sample >>= 1;
315	sample \|= ((rm->ubuf[led] >= 0x80) << 15);
316	}
317	return (sample << 17) \| (sample >> 15);
318	}
319
320	static irqreturn_t rackmeter_irq(int irq, void *arg)
321	{
322	struct rackmeter *rm = arg;
323	struct rackmeter_dma *db = rm->dma_buf_v;
324	unsigned int mark, i;
325	u32 *buf;
326
327	/* Flush PCI buffers with an MMIO read. Maybe we could actually
328	* check the status one day ... in case things go wrong, though
329	* this never happened to me
330	*/
331	(void)in_le32(&rm->dma_regs->status);
332
333	/* Make sure the CPU gets us in order */
334	rmb();
335
336	/* Read mark */
337	mark = db->mark;
338	if (mark != 1 && mark != 2) {
339	printk(KERN_WARNING "rackmeter: Incorrect DMA mark 0x%08x\n",
340	mark);
341	/* We allow for 3 errors like that (stale DBDMA irqs) */
342	if (++rm->stale_irq > 3) {
343	printk(KERN_ERR "rackmeter: Too many errors,"
344	" stopping DMA\n");
345	DBDMA_DO_RESET(rm->dma_regs);
346	}
347	return IRQ_HANDLED;
348	}
349
350	/* Next buffer we need to fill is mark value */
351	buf = mark == 1 ? db->buf1 : db->buf2;
352
353	/* Fill it now. This routine converts the 8 bits depth sample array
354	* into the PWM bitmap for each LED.
355	*/
356	for (i = 0; i < SAMPLE_COUNT; i++)
357	buf[i] = rackmeter_calc_sample(rm, i);
358
359
360	return IRQ_HANDLED;
361	}
362
363	static int __devinit rackmeter_probe(struct macio_dev* mdev,
364	const struct of_device_id *match)
365	{
366	struct device_node i2s = NULL, np = NULL;
367	struct rackmeter *rm = NULL;
368	struct resource ri2s, rdma;
369	int rc = -ENODEV;
370
371	pr_debug("rackmeter_probe()\n");
372
373	/* Get i2s-a node */
374	while ((i2s = of_get_next_child(mdev->ofdev.node, i2s)) != NULL)
375	if (strcmp(i2s->name, "i2s-a") == 0)
376	break;
377	if (i2s == NULL) {
378	pr_debug(" i2s-a child not found\n");
379	goto bail;
380	}
381	/* Get lightshow or virtual sound */
382	while ((np = of_get_next_child(i2s, np)) != NULL) {
383	if (strcmp(np->name, "lightshow") == 0)
384	break;
385	if ((strcmp(np->name, "sound") == 0) &&
386	get_property(np, "virtual", NULL) != NULL)
387	break;
388	}
389	if (np == NULL) {
390	pr_debug(" lightshow or sound+virtual child not found\n");
391	goto bail;
392	}
393
394	/* Create and initialize our instance data */
395	rm = kzalloc(sizeof(struct rackmeter), GFP_KERNEL);
396	if (rm == NULL) {
397	printk(KERN_ERR "rackmeter: failed to allocate memory !\n");
398	rc = -ENOMEM;
399	goto bail_release;
400	}
401	rm->mdev = mdev;
402	rm->i2s = i2s;
403	mutex_init(&rm->sem);
404	dev_set_drvdata(&mdev->ofdev.dev, rm);
405	/* Check resources availability. We need at least resource 0 and 1 */
406	#if 0 /* Use that when i2s-a is finally an mdev per-se */
407	if (macio_resource_count(mdev) < 2 \|\| macio_irq_count(mdev) < 2) {
408	printk(KERN_ERR
409	"rackmeter: found match but lacks resources: %s"
410	" (%d resources, %d interrupts)\n",
411	mdev->ofdev.node->full_name);
412	rc = -ENXIO;
413	goto bail_free;
414	}
415	if (macio_request_resources(mdev, "rackmeter")) {
416	printk(KERN_ERR
417	"rackmeter: failed to request resources: %s\n",
418	mdev->ofdev.node->full_name);
419	rc = -EBUSY;
420	goto bail_free;
421	}
422	rm->irq = macio_irq(mdev, 1);
423	#else
424	rm->irq = irq_of_parse_and_map(i2s, 1);
425	if (rm->irq == NO_IRQ \|\|
426	of_address_to_resource(i2s, 0, &ri2s) \|\|
427	of_address_to_resource(i2s, 1, &rdma)) {
428	printk(KERN_ERR
429	"rackmeter: found match but lacks resources: %s",
430	mdev->ofdev.node->full_name);
431	rc = -ENXIO;
432	goto bail_free;
433	}
434	#endif
435
436	pr_debug(" i2s @0x%08x\n", (unsigned int)ri2s.start);
437	pr_debug(" dma @0x%08x\n", (unsigned int)rdma.start);
438	pr_debug(" irq %d\n", rm->irq);
439
440	rm->ubuf = (u8 *)__get_free_page(GFP_KERNEL);
441	if (rm->ubuf == NULL) {
442	printk(KERN_ERR
443	"rackmeter: failed to allocate samples page !\n");
444	rc = -ENOMEM;
445	goto bail_release;
446	}
447
448	rm->dma_buf_v = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev,
449	sizeof(struct rackmeter_dma),
450	&rm->dma_buf_p, GFP_KERNEL);
451	if (rm->dma_buf_v == NULL) {
452	printk(KERN_ERR
453	"rackmeter: failed to allocate dma buffer !\n");
454	rc = -ENOMEM;
455	goto bail_free_samples;
456	}
457	#if 0
458	rm->i2s_regs = ioremap(macio_resource_start(mdev, 0), 0x1000);
459	#else
460	rm->i2s_regs = ioremap(ri2s.start, 0x1000);
461	#endif
462	if (rm->i2s_regs == NULL) {
463	printk(KERN_ERR
464	"rackmeter: failed to map i2s registers !\n");
465	rc = -ENXIO;
466	goto bail_free_dma;
467	}
468	#if 0
469	rm->dma_regs = ioremap(macio_resource_start(mdev, 1), 0x100);
470	#else
471	rm->dma_regs = ioremap(rdma.start, 0x100);
472	#endif
473	if (rm->dma_regs == NULL) {
474	printk(KERN_ERR
475	"rackmeter: failed to map dma registers !\n");
476	rc = -ENXIO;
477	goto bail_unmap_i2s;
478	}
479
480	rc = rackmeter_setup(rm);
481	if (rc) {
482	printk(KERN_ERR
483	"rackmeter: failed to initialize !\n");
484	rc = -ENXIO;
485	goto bail_unmap_dma;
486	}
487
488	rc = request_irq(rm->irq, rackmeter_irq, 0, "rackmeter", rm);
489	if (rc != 0) {
490	printk(KERN_ERR
491	"rackmeter: failed to request interrupt !\n");
492	goto bail_stop_dma;
493	}
494	of_node_put(np);
495	return 0;
496
497	bail_stop_dma:
498	DBDMA_DO_RESET(rm->dma_regs);
499	bail_unmap_dma:
500	iounmap(rm->dma_regs);
501	bail_unmap_i2s:
502	iounmap(rm->i2s_regs);
503	bail_free_dma:
504	dma_free_coherent(&macio_get_pci_dev(mdev)->dev,
505	sizeof(struct rackmeter_dma),
506	rm->dma_buf_v, rm->dma_buf_p);
507	bail_free_samples:
508	free_page((unsigned long)rm->ubuf);
509	bail_release:
510	#if 0
511	macio_release_resources(mdev);
512	#endif
513	bail_free:
514	kfree(rm);
515	bail:
516	of_node_put(i2s);
517	of_node_put(np);
518	dev_set_drvdata(&mdev->ofdev.dev, NULL);
519	return rc;
520	}
521
522	static int __devexit rackmeter_remove(struct macio_dev* mdev)
523	{
524	struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev);
525
526	/* Stop CPU sniffer timer & work queues */
527	rackmeter_stop_cpu_sniffer(rm);
528
529	/* Clear reference to private data */
530	dev_set_drvdata(&mdev->ofdev.dev, NULL);
531
532	/* Stop/reset dbdma */
533	DBDMA_DO_RESET(rm->dma_regs);
534
535	/* Release the IRQ */
536	free_irq(rm->irq, rm);
537
538	/* Unmap registers */
539	iounmap(rm->dma_regs);
540	iounmap(rm->i2s_regs);
541
542	/* Free DMA */
543	dma_free_coherent(&macio_get_pci_dev(mdev)->dev,
544	sizeof(struct rackmeter_dma),
545	rm->dma_buf_v, rm->dma_buf_p);
546
547	/* Free samples */
548	free_page((unsigned long)rm->ubuf);
549
550	#if 0
551	/* Release resources */
552	macio_release_resources(mdev);
553	#endif
554
555	/* Get rid of me */
556	kfree(rm);
557
558	return 0;
559	}
560
561	static int rackmeter_shutdown(struct macio_dev* mdev)
562	{
563	struct rackmeter *rm = dev_get_drvdata(&mdev->ofdev.dev);
564
565	if (rm == NULL)
566	return -ENODEV;
567
568	/* Stop CPU sniffer timer & work queues */
569	rackmeter_stop_cpu_sniffer(rm);
570
571	/* Stop/reset dbdma */
572	DBDMA_DO_RESET(rm->dma_regs);
573
574	return 0;
575	}
576
577	static struct of_device_id rackmeter_match[] = {
578	{ .name = "i2s" },
579	{ }
580	};
581
582	static struct macio_driver rackmeter_drv = {
583	.name = "rackmeter",
584	.owner = THIS_MODULE,
585	.match_table = rackmeter_match,
586	.probe = rackmeter_probe,
587	.remove = rackmeter_remove,
588	.shutdown = rackmeter_shutdown,
589	};
590
591
592	static int __init rackmeter_init(void)
593	{
594	pr_debug("rackmeter_init()\n");
595
596	return macio_register_driver(&rackmeter_drv);
597	}
598
599	static void __exit rackmeter_exit(void)
600	{
601	pr_debug("rackmeter_exit()\n");
602
603	macio_unregister_driver(&rackmeter_drv);
604	}
605
606	module_init(rackmeter_init);
607	module_exit(rackmeter_exit);
608
609
610	MODULE_LICENSE("GPL");
611	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
612	MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel");