rack-meter.c

来自「linux 内核源代码」· C语言 代码 · 共 616 行 · 第 1/2 页

/*  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_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 <[e-mail]>");
MODULE_DESCRIPTION("RackMeter: Support vu-meter on XServe front panel");