sound/aoa/soundbus/i2sbus/i2sbus-core.c - linux - Git at Google

 /*
  * i2sbus driver
  *
  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
  *
  * GPL v2, can be found in COPYING.
  */

 #include <linux/module.h>
 #include <asm/macio.h>
 #include <asm/dbdma.h>
 #include <linux/pci.h>
 #include <linux/interrupt.h>
 #include <sound/driver.h>
 #include <sound/core.h>
 #include <linux/dma-mapping.h>
 #include "../soundbus.h"
 #include "i2sbus.h"

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
 MODULE_DESCRIPTION("Apple Soundbus: I2S support");
 /* for auto-loading, declare that we handle this weird
  * string that macio puts into the relevant device */
 MODULE_ALIAS("of:Ni2sTi2sC");

 static struct of_device_id i2sbus_match[] = {
 	{ .name = "i2s" },
 	{ }
 };

 static int alloc_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
 				       struct dbdma_command_mem *r,
 				       int numcmds)
 {
 	/* one more for rounding */
 	r->size = (numcmds+1) * 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_alloc_coherent(
 			&macio_get_pci_dev(i2sdev->macio)->dev,
 			r->size,
 			&r->bus_addr,
 			GFP_KERNEL);

 	if (!r->space) return -ENOMEM;

 	memset(r->space, 0, r->size);
 	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=0;i<3;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=0;i<3;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 pt_regs *regs)
 {
 	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;
 }

 static int force;
 module_param(force, int, 0444);
 MODULE_PARM_DESC(force, "Force loading i2sbus even when"
 			" no layout-id property is present");

 /* 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;
 	int i;
 	static const char *rnames[] = { "i2sbus: %s (control)",
 					"i2sbus: %s (tx)",
 					"i2sbus: %s (rx)" };
 	static irqreturn_t (*ints[])(int irq, void *devid,
 				     struct pt_regs *regs) = {
 		i2sbus_bus_intr,
 		i2sbus_tx_intr,
 		i2sbus_rx_intr
 	};

 	if (strlen(np->name) != 5)
 		return 0;
 	if (strncmp(np->name, "i2s-", 4))
 		return 0;

 	if (macio_irq_count(macio) != 3)
 		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) {
 		u32 *layout_id;
 		layout_id = (u32*) get_property(sound, "layout-id", NULL);
 		if (layout_id) {
 			snprintf(dev->sound.modalias, 32,
 				 "sound-layout-%d", *layout_id);
 			force = 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 (!force) {
 		kfree(dev);
 		return -ENODEV;
 	}

 	mutex_init(&dev->lock);
 	spin_lock_init(&dev->low_lock);
 	dev->sound.ofdev.node = np;
 	dev->sound.ofdev.dma_mask = macio->ofdev.dma_mask;
 	dev->sound.ofdev.dev.dma_mask = &dev->sound.ofdev.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=0;i<3;i++) {
 		dev->interrupts[i] = -1;
 		snprintf(dev->rnames[i], sizeof(dev->rnames[i]), rnames[i], np->name);
 	}
 	for (i=0;i<3;i++) {
 		if (request_irq(macio_irq(macio, i), ints[i], 0,
 				dev->rnames[i], dev))
 			goto err;
 		dev->interrupts[i] = macio_irq(macio, i);
 	}

 	for (i=0;i<3;i++) {
 		if (of_address_to_resource(np, i, &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,
 					   dev->resources[i].end -
 					   dev->resources[i].start + 1,
 					   dev->rnames[i]);
 		if (!dev->allocated_resource[i]) {
 			printk(KERN_ERR "i2sbus: failed to claim resource %d!\n", i);
 			goto err;
 		}
 	}
 	/* should do sanity checking here about length of them */
 	dev->intfregs = ioremap(dev->resources[0].start,
 				dev->resources[0].end-dev->resources[0].start+1);
 	dev->out.dbdma = ioremap(dev->resources[1].start,
 			 	 dev->resources[1].end-dev->resources[1].start+1);
 	dev->in.dbdma = ioremap(dev->resources[2].start,
 				dev->resources[2].end-dev->resources[2].start+1);
 	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.node, np))) {
 		if (device_is_compatible(np, "i2sbus") ||
 		    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->ofdev.dev.driver_data = control;

 	return 0;
 }

 static int i2sbus_remove(struct macio_dev* dev)
 {
 	struct i2sbus_control *control = dev->ofdev.dev.driver_data;
 	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->ofdev.dev.driver_data;
 	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);
 			/* Probably useless as we handle
 			 * power transitions ourselves */
 			snd_power_change_state(i2sdev->sound.pcm->card,
 					       SNDRV_CTL_POWER_D3hot);
 		}
 		/* 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;
 		}
 	}
 	return ret;
 }

 static int i2sbus_resume(struct macio_dev* dev)
 {
 	struct i2sbus_control *control = dev->ofdev.dev.driver_data;
 	struct codec_info_item *cii;
 	struct i2sbus_dev* i2sdev;
 	int err, ret = 0;

 	list_for_each_entry(i2sdev, &control->list, item) {
 		/* 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;
 		}
 		/* Notify Alsa */
 		if (i2sdev->sound.pcm) {
 			/* Same comment as above, probably useless */
 			snd_power_change_state(i2sdev->sound.pcm->card,
 					       SNDRV_CTL_POWER_D0);
 		}
 	}

 	return ret;
 }
 #endif /* CONFIG_PM */

 static int i2sbus_shutdown(struct macio_dev* dev)
 {
 	return 0;
 }

 static struct macio_driver i2sbus_drv = {
 	.name = "soundbus-i2s",
 	.owner = THIS_MODULE,
 	.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);
	/*
	* i2sbus driver
	*
	* Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
	*
	* GPL v2, can be found in COPYING.
	*/

	#include <linux/module.h>
	#include <asm/macio.h>
	#include <asm/dbdma.h>
	#include <linux/pci.h>
	#include <linux/interrupt.h>
	#include <sound/driver.h>
	#include <sound/core.h>
	#include <linux/dma-mapping.h>
	#include "../soundbus.h"
	#include "i2sbus.h"

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
	MODULE_DESCRIPTION("Apple Soundbus: I2S support");
	/* for auto-loading, declare that we handle this weird
	* string that macio puts into the relevant device */
	MODULE_ALIAS("of:Ni2sTi2sC");

	static struct of_device_id i2sbus_match[] = {
	{ .name = "i2s" },
	{ }
	};

	static int alloc_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
	struct dbdma_command_mem *r,
	int numcmds)
	{
	/* one more for rounding */
	r->size = (numcmds+1) * 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_alloc_coherent(
	&macio_get_pci_dev(i2sdev->macio)->dev,
	r->size,
	&r->bus_addr,
	GFP_KERNEL);

	if (!r->space) return -ENOMEM;

	memset(r->space, 0, r->size);
	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=0;i<3;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=0;i<3;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 pt_regs regs)
	{
	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;
	}

	static int force;
	module_param(force, int, 0444);
	MODULE_PARM_DESC(force, "Force loading i2sbus even when"
	" no layout-id property is present");

	/* 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;
	int i;
	static const char *rnames[] = { "i2sbus: %s (control)",
	"i2sbus: %s (tx)",
	"i2sbus: %s (rx)" };
	static irqreturn_t (ints[])(int irq, void devid,
	struct pt_regs *regs) = {
	i2sbus_bus_intr,
	i2sbus_tx_intr,
	i2sbus_rx_intr
	};

	if (strlen(np->name) != 5)
	return 0;
	if (strncmp(np->name, "i2s-", 4))
	return 0;

	if (macio_irq_count(macio) != 3)
	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) {
	u32 *layout_id;
	layout_id = (u32*) get_property(sound, "layout-id", NULL);
	if (layout_id) {
	snprintf(dev->sound.modalias, 32,
	"sound-layout-%d", *layout_id);
	force = 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 (!force) {
	kfree(dev);
	return -ENODEV;
	}

	mutex_init(&dev->lock);
	spin_lock_init(&dev->low_lock);
	dev->sound.ofdev.node = np;
	dev->sound.ofdev.dma_mask = macio->ofdev.dma_mask;
	dev->sound.ofdev.dev.dma_mask = &dev->sound.ofdev.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=0;i<3;i++) {
	dev->interrupts[i] = -1;
	snprintf(dev->rnames[i], sizeof(dev->rnames[i]), rnames[i], np->name);
	}
	for (i=0;i<3;i++) {
	if (request_irq(macio_irq(macio, i), ints[i], 0,
	dev->rnames[i], dev))
	goto err;
	dev->interrupts[i] = macio_irq(macio, i);
	}

	for (i=0;i<3;i++) {
	if (of_address_to_resource(np, i, &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,
	dev->resources[i].end -
	dev->resources[i].start + 1,
	dev->rnames[i]);
	if (!dev->allocated_resource[i]) {
	printk(KERN_ERR "i2sbus: failed to claim resource %d!\n", i);
	goto err;
	}
	}
	/* should do sanity checking here about length of them */
	dev->intfregs = ioremap(dev->resources[0].start,
	dev->resources[0].end-dev->resources[0].start+1);
	dev->out.dbdma = ioremap(dev->resources[1].start,
	dev->resources[1].end-dev->resources[1].start+1);
	dev->in.dbdma = ioremap(dev->resources[2].start,
	dev->resources[2].end-dev->resources[2].start+1);
	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.node, np))) {
	if (device_is_compatible(np, "i2sbus") \|\|
	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->ofdev.dev.driver_data = control;

	return 0;
	}

	static int i2sbus_remove(struct macio_dev* dev)
	{
	struct i2sbus_control *control = dev->ofdev.dev.driver_data;
	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->ofdev.dev.driver_data;
	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);
	/* Probably useless as we handle
	* power transitions ourselves */
	snd_power_change_state(i2sdev->sound.pcm->card,
	SNDRV_CTL_POWER_D3hot);
	}
	/* 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;
	}
	}
	return ret;
	}

	static int i2sbus_resume(struct macio_dev* dev)
	{
	struct i2sbus_control *control = dev->ofdev.dev.driver_data;
	struct codec_info_item *cii;
	struct i2sbus_dev* i2sdev;
	int err, ret = 0;

	list_for_each_entry(i2sdev, &control->list, item) {
	/* 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;
	}
	/* Notify Alsa */
	if (i2sdev->sound.pcm) {
	/* Same comment as above, probably useless */
	snd_power_change_state(i2sdev->sound.pcm->card,
	SNDRV_CTL_POWER_D0);
	}
	}

	return ret;
	}
	#endif /* CONFIG_PM */

	static int i2sbus_shutdown(struct macio_dev* dev)
	{
	return 0;
	}

	static struct macio_driver i2sbus_drv = {
	.name = "soundbus-i2s",
	.owner = THIS_MODULE,
	.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);