text: /*
   * i2sbus driver
   *
   * Copyright 2006-2008 Johannes Berg <johannes@sipsolutions.net>
   *
   * GPL v2, can be found in COPYING.
   */
  
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/pci.h>
  #include <linux/interrupt.h>
  #include <linux/dma-mapping.h>
  #include <linux/of_address.h>
  #include <linux/of_irq.h>
  
  #include <sound/core.h>
  
  #include <asm/macio.h>
  #include <asm/dbdma.h>
  
  #include "../soundbus.h"
  #include "i2sbus.h"
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
  MODULE_DESCRIPTION("Apple Soundbus: I2S support");
  
  static int force;
  module_param(force, int, 0444);
  MODULE_PARM_DESC(force, "Force loading i2sbus even when"
  			" no layout-id property is present");
  
  static struct of_device_id i2sbus_match[] = {
  	{ .name = "i2s" },
  	{ }
  };
  
  MODULE_DEVICE_TABLE(of, i2sbus_match);
  
  static int alloc_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
  				       struct dbdma_command_mem *r,
  				       int numcmds)
  {
  	/* one more for rounding, one for branch back, one for stop command */
  	r->size = (numcmds + 3) * sizeof(struct dbdma_cmd);
  	/* We use the PCI APIs for now until the generic one gets fixed
  	 * enough or until we get some macio-specific versions
  	 */
  	r->space = dma_zalloc_coherent(&macio_get_pci_dev(i2sdev->macio)->dev,
  				       r->size, &r->bus_addr, GFP_KERNEL);
  	if (!r->space)
  		return -ENOMEM;
  
  	r->cmds = (void*)DBDMA_ALIGN(r->space);
  	r->bus_cmd_start = r->bus_addr +
  			   (dma_addr_t)((char*)r->cmds - (char*)r->space);
  
  	return 0;
  }
  
  static void free_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
  				       struct dbdma_command_mem *r)
  {
  	if (!r->space) return;
  
  	dma_free_coherent(&macio_get_pci_dev(i2sdev->macio)->dev,
  			    r->size, r->space, r->bus_addr);
  }
  
  static void i2sbus_release_dev(struct device *dev)
  {
  	struct i2sbus_dev *i2sdev;
  	int i;
  
  	i2sdev = container_of(dev, struct i2sbus_dev, sound.ofdev.dev);
  
   	if (i2sdev->intfregs) iounmap(i2sdev->intfregs);
   	if (i2sdev->out.dbdma) iounmap(i2sdev->out.dbdma);
   	if (i2sdev->in.dbdma) iounmap(i2sdev->in.dbdma);
  	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++)
  		if (i2sdev->allocated_resource[i])
  			release_and_free_resource(i2sdev->allocated_resource[i]);
  	free_dbdma_descriptor_ring(i2sdev, &i2sdev->out.dbdma_ring);
  	free_dbdma_descriptor_ring(i2sdev, &i2sdev->in.dbdma_ring);
  	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++)
  		free_irq(i2sdev->interrupts[i], i2sdev);
  	i2sbus_control_remove_dev(i2sdev->control, i2sdev);
  	mutex_destroy(&i2sdev->lock);
  	kfree(i2sdev);
  }
  
  static irqreturn_t i2sbus_bus_intr(int irq, void *devid)
  {
  	struct i2sbus_dev *dev = devid;
  	u32 intreg;
  
  	spin_lock(&dev->low_lock);
  	intreg = in_le32(&dev->intfregs->intr_ctl);
  
  	/* acknowledge interrupt reasons */
  	out_le32(&dev->intfregs->intr_ctl, intreg);
  
  	spin_unlock(&dev->low_lock);
  
  	return IRQ_HANDLED;
  }
  
  
  /*
   * XXX FIXME: We test the layout_id's here to get the proper way of
   * mapping in various registers, thanks to bugs in Apple device-trees.
   * We could instead key off the machine model and the name of the i2s
   * node (i2s-a). This we'll do when we move it all to macio_asic.c
   * and have that export items for each sub-node too.
   */
  static int i2sbus_get_and_fixup_rsrc(struct device_node *np, int index,
  				     int layout, struct resource *res)
  {
  	struct device_node *parent;
  	int pindex, rc = -ENXIO;
  	const u32 *reg;
  
  	/* Machines with layout 76 and 36 (K2 based) have a weird device
  	 * tree what we need to special case.
  	 * Normal machines just fetch the resource from the i2s-X node.
  	 * Darwin further divides normal machines into old and new layouts
  	 * with a subtely different code path but that doesn't seem necessary
  	 * in practice, they just bloated it. In addition, even on our K2
  	 * case the i2s-modem node, if we ever want to handle it, uses the
  	 * normal layout
  	 */
  	if (layout != 76 && layout != 36)
  		return of_address_to_resource(np, index, res);
  
  	parent = of_get_parent(np);
  	pindex = (index == aoa_resource_i2smmio) ? 0 : 1;
  	rc = of_address_to_resource(parent, pindex, res);
  	if (rc)
  		goto bail;
  	reg = of_get_property(np, "reg", NULL);
  	if (reg == NULL) {
  		rc = -ENXIO;
  		goto bail;
  	}
  	res->start += reg[index * 2];
  	res->end = res->start + reg[index * 2 + 1] - 1;
   bail:
  	of_node_put(parent);
  	return rc;
  }
  
  /* FIXME: look at device node refcounting */
  static int i2sbus_add_dev(struct macio_dev *macio,
  			  struct i2sbus_control *control,
  			  struct device_node *np)
  {
  	struct i2sbus_dev *dev;
  	struct device_node *child = NULL, *sound = NULL;
  	struct resource *r;
  	int i, layout = 0, rlen, ok = force;
  	static const char *rnames[] = { "i2sbus: %s (control)",
  					"i2sbus: %s (tx)",
  					"i2sbus: %s (rx)" };
  	static irq_handler_t ints[] = {
  		i2sbus_bus_intr,
  		i2sbus_tx_intr,
  		i2sbus_rx_intr
  	};
  
  	if (strlen(np->name) != 5)
  		return 0;
  	if (strncmp(np->name, "i2s-", 4))
  		return 0;
  
  	dev = kzalloc(sizeof(struct i2sbus_dev), GFP_KERNEL);
  	if (!dev)
  		return 0;
  
  	i = 0;
  	while ((child = of_get_next_child(np, child))) {
  		if (strcmp(child->name, "sound") == 0) {
  			i++;
  			sound = child;
  		}
  	}
  	if (i == 1) {
  		const u32 *id = of_get_property(sound, "layout-id", NULL);
  
  		if (id) {
  			layout = *id;
  			snprintf(dev->sound.modalias, 32,
  				 "sound-layout-%d", layout);
  			ok = 1;
  		} else {
  			id = of_get_property(sound, "device-id", NULL);
  			/*
  			 * We probably cannot handle all device-id machines,
  			 * so restrict to those we do handle for now.
  			 */
  			if (id && (*id == 22 || *id == 14 || *id == 35 ||
  				   *id == 44)) {
  				snprintf(dev->sound.modalias, 32,
  					 "aoa-device-id-%d", *id);
  				ok = 1;
  				layout = -1;
  			}
  		}
  	}
  	/* for the time being, until we can handle non-layout-id
  	 * things in some fabric, refuse to attach if there is no
  	 * layout-id property or we haven't been forced to attach.
  	 * When there are two i2s busses and only one has a layout-id,
  	 * then this depends on the order, but that isn't important
  	 * either as the second one in that case is just a modem. */
  	if (!ok) {
  		kfree(dev);
  		return -ENODEV;
  	}
  
  	mutex_init(&dev->lock);
  	spin_lock_init(&dev->low_lock);
  	dev->sound.ofdev.archdata.dma_mask = macio->ofdev.archdata.dma_mask;
  	dev->sound.ofdev.dev.of_node = np;
  	dev->sound.ofdev.dev.dma_mask = &dev->sound.ofdev.archdata.dma_mask;
  	dev->sound.ofdev.dev.parent = &macio->ofdev.dev;
  	dev->sound.ofdev.dev.release = i2sbus_release_dev;
  	dev->sound.attach_codec = i2sbus_attach_codec;
  	dev->sound.detach_codec = i2sbus_detach_codec;
  	dev->sound.pcmid = -1;
  	dev->macio = macio;
  	dev->control = control;
  	dev->bus_number = np->name[4] - 'a';
  	INIT_LIST_HEAD(&dev->sound.codec_list);
  
  	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
  		dev->interrupts[i] = -1;
  		snprintf(dev->rnames[i], sizeof(dev->rnames[i]),
  			 rnames[i], np->name);
  	}
  	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
  		int irq = irq_of_parse_and_map(np, i);
  		if (request_irq(irq, ints[i], 0, dev->rnames[i], dev))
  			goto err;
  		dev->interrupts[i] = irq;
  	}
  
  
  	/* Resource handling is problematic as some device-trees contain
  	 * useless crap (ugh ugh ugh). We work around that here by calling
  	 * specific functions for calculating the appropriate resources.
  	 *
  	 * This will all be moved to macio_asic.c at one point
  	 */
  	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
  		if (i2sbus_get_and_fixup_rsrc(np,i,layout,&dev->resources[i]))
  			goto err;
  		/* If only we could use our resource dev->resources[i]...
  		 * but request_resource doesn't know about parents and
  		 * contained resources...
  		 */
  		dev->allocated_resource[i] =
  			request_mem_region(dev->resources[i].start,
  					   resource_size(&dev->resources[i]),
  					   dev->rnames[i]);
  		if (!dev->allocated_resource[i]) {
  			printk(KERN_ERR "i2sbus: failed to claim resource %d!\n", i);
  			goto err;
  		}
  	}
  
  	r = &dev->resources[aoa_resource_i2smmio];
  	rlen = resource_size(r);
  	if (rlen < sizeof(struct i2s_interface_regs))
  		goto err;
  	dev->intfregs = ioremap(r->start, rlen);
  
  	r = &dev->resources[aoa_resource_txdbdma];
  	rlen = resource_size(r);
  	if (rlen < sizeof(struct dbdma_regs))
  		goto err;
  	dev->out.dbdma = ioremap(r->start, rlen);
  
  	r = &dev->resources[aoa_resource_rxdbdma];
  	rlen = resource_size(r);
  	if (rlen < sizeof(struct dbdma_regs))
  		goto err;
  	dev->in.dbdma = ioremap(r->start, rlen);
  
  	if (!dev->intfregs || !dev->out.dbdma || !dev->in.dbdma)
  		goto err;
  
  	if (alloc_dbdma_descriptor_ring(dev, &dev->out.dbdma_ring,
  					MAX_DBDMA_COMMANDS))
  		goto err;
  	if (alloc_dbdma_descriptor_ring(dev, &dev->in.dbdma_ring,
  					MAX_DBDMA_COMMANDS))
  		goto err;
  
  	if (i2sbus_control_add_dev(dev->control, dev)) {
  		printk(KERN_ERR "i2sbus: control layer didn't like bus\n");
  		goto err;
  	}
  
  	if (soundbus_add_one(&dev->sound)) {
  		printk(KERN_DEBUG "i2sbus: device registration error!\n");
  		goto err;
  	}
  
  	/* enable this cell */
  	i2sbus_control_cell(dev->control, dev, 1);
  	i2sbus_control_enable(dev->control, dev);
  	i2sbus_control_clock(dev->control, dev, 1);
  
  	return 1;
   err:
  	for (i=0;i<3;i++)
  		if (dev->interrupts[i] != -1)
  			free_irq(dev->interrupts[i], dev);
  	free_dbdma_descriptor_ring(dev, &dev->out.dbdma_ring);
  	free_dbdma_descriptor_ring(dev, &dev->in.dbdma_ring);
  	if (dev->intfregs) iounmap(dev->intfregs);
  	if (dev->out.dbdma) iounmap(dev->out.dbdma);
  	if (dev->in.dbdma) iounmap(dev->in.dbdma);
  	for (i=0;i<3;i++)
  		if (dev->allocated_resource[i])
  			release_and_free_resource(dev->allocated_resource[i]);
  	mutex_destroy(&dev->lock);
  	kfree(dev);
  	return 0;
  }
  
  static int i2sbus_probe(struct macio_dev* dev, const struct of_device_id *match)
  {
  	struct device_node *np = NULL;
  	int got = 0, err;
  	struct i2sbus_control *control = NULL;
  
  	err = i2sbus_control_init(dev, &control);
  	if (err)
  		return err;
  	if (!control) {
  		printk(KERN_ERR "i2sbus_control_init API breakage\n");
  		return -ENODEV;
  	}
  
  	while ((np = of_get_next_child(dev->ofdev.dev.of_node, np))) {
  		if (of_device_is_compatible(np, "i2sbus") ||
  		    of_device_is_compatible(np, "i2s-modem")) {
  			got += i2sbus_add_dev(dev, control, np);
  		}
  	}
  
  	if (!got) {
  		/* found none, clean up */
  		i2sbus_control_destroy(control);
  		return -ENODEV;
  	}
  
  	dev_set_drvdata(&dev->ofdev.dev, control);
  
  	return 0;
  }
  
  static int i2sbus_remove(struct macio_dev* dev)
  {
  	struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
  	struct i2sbus_dev *i2sdev, *tmp;
  
  	list_for_each_entry_safe(i2sdev, tmp, &control->list, item)
  		soundbus_remove_one(&i2sdev->sound);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static int i2sbus_suspend(struct macio_dev* dev, pm_message_t state)
  {
  	struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
  	struct codec_info_item *cii;
  	struct i2sbus_dev* i2sdev;
  	int err, ret = 0;
  
  	list_for_each_entry(i2sdev, &control->list, item) {
  		/* Notify Alsa */
  		if (i2sdev->sound.pcm) {
  			/* Suspend PCM streams */
  			snd_pcm_suspend_all(i2sdev->sound.pcm);
  		}
  
  		/* Notify codecs */
  		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
  			err = 0;
  			if (cii->codec->suspend)
  				err = cii->codec->suspend(cii, state);
  			if (err)
  				ret = err;
  		}
  
  		/* wait until streams are stopped */
  		i2sbus_wait_for_stop_both(i2sdev);
  	}
  
  	return ret;
  }
  
  static int i2sbus_resume(struct macio_dev* dev)
  {
  	struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
  	struct codec_info_item *cii;
  	struct i2sbus_dev* i2sdev;
  	int err, ret = 0;
  
  	list_for_each_entry(i2sdev, &control->list, item) {
  		/* reset i2s bus format etc. */
  		i2sbus_pcm_prepare_both(i2sdev);
  
  		/* Notify codecs so they can re-initialize */
  		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
  			err = 0;
  			if (cii->codec->resume)
  				err = cii->codec->resume(cii);
  			if (err)
  				ret = err;
  		}
  	}
  
  	return ret;
  }
  #endif /* CONFIG_PM */
  
  static int i2sbus_shutdown(struct macio_dev* dev)
  {
  	return 0;
  }
  
  static struct macio_driver i2sbus_drv = {
  	.driver = {
  		.name = "soundbus-i2s",
  		.owner = THIS_MODULE,
  		.of_match_table = i2sbus_match,
  	},
  	.probe = i2sbus_probe,
  	.remove = i2sbus_remove,
  #ifdef CONFIG_PM
  	.suspend = i2sbus_suspend,
  	.resume = i2sbus_resume,
  #endif
  	.shutdown = i2sbus_shutdown,
  };
  
  static int __init soundbus_i2sbus_init(void)
  {
  	return macio_register_driver(&i2sbus_drv);
  }
  
  static void __exit soundbus_i2sbus_exit(void)
  {
  	macio_unregister_driver(&i2sbus_drv);
  }
  
  module_init(soundbus_i2sbus_init);
  module_exit(soundbus_i2sbus_exit);
  