205 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			205 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * soundbus generic definitions
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|  *
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|  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
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|  *
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|  * GPL v2, can be found in COPYING.
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|  */
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| #ifndef __SOUNDBUS_H
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| #define __SOUNDBUS_H
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| 
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| #include <linux/of_device.h>
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| #include <sound/pcm.h>
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| #include <linux/list.h>
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| 
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| 
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| /* When switching from master to slave or the other way around,
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|  * you don't want to have the codec chip acting as clock source
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|  * while the bus still is.
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|  * More importantly, while switch from slave to master, you need
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|  * to turn off the chip's master function first, but then there's
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|  * no clock for a while and other chips might reset, so we notify
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|  * their drivers after having switched.
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|  * The constants here are codec-point of view, so when we switch
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|  * the soundbus to master we tell the codec we're going to switch
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|  * and give it CLOCK_SWITCH_PREPARE_SLAVE!
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|  */
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| enum clock_switch {
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| 	CLOCK_SWITCH_PREPARE_SLAVE,
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| 	CLOCK_SWITCH_PREPARE_MASTER,
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| 	CLOCK_SWITCH_SLAVE,
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| 	CLOCK_SWITCH_MASTER,
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| 	CLOCK_SWITCH_NOTIFY,
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| };
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| 
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| /* information on a transfer the codec can take */
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| struct transfer_info {
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| 	u64 formats;		/* SNDRV_PCM_FMTBIT_* */
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| 	unsigned int rates;	/* SNDRV_PCM_RATE_* */
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| 	/* flags */
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| 	u32 transfer_in:1, /* input = 1, output = 0 */
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| 	    must_be_clock_source:1;
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| 	/* for codecs to distinguish among their TIs */
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| 	int tag;
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| };
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| 
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| struct codec_info_item {
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| 	struct codec_info *codec;
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| 	void *codec_data;
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| 	struct soundbus_dev *sdev;
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| 	/* internal, to be used by the soundbus provider */
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| 	struct list_head list;
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| };
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| 
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| /* for prepare, where the codecs need to know
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|  * what we're going to drive the bus with */
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| struct bus_info {
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| 	/* see below */
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| 	int sysclock_factor;
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| 	int bus_factor;
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| };
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| 
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| /* information on the codec itself, plus function pointers */
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| struct codec_info {
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| 	/* the module this lives in */
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| 	struct module *owner;
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| 
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| 	/* supported transfer possibilities, array terminated by
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| 	 * formats or rates being 0. */
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| 	struct transfer_info *transfers;
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| 
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| 	/* Master clock speed factor
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| 	 * to be used (master clock speed = sysclock_factor * sampling freq)
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| 	 * Unused if the soundbus provider has no such notion.
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| 	 */
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| 	int sysclock_factor;
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| 
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| 	/* Bus factor, bus clock speed = bus_factor * sampling freq)
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| 	 * Unused if the soundbus provider has no such notion.
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| 	 */
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| 	int bus_factor;
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| 
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| 	/* operations */
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| 	/* clock switching, see above */
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| 	int (*switch_clock)(struct codec_info_item *cii,
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| 			    enum clock_switch clock);
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| 
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| 	/* called for each transfer_info when the user
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| 	 * opens the pcm device to determine what the
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| 	 * hardware can support at this point in time.
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| 	 * That can depend on other user-switchable controls.
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| 	 * Return 1 if usable, 0 if not.
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| 	 * out points to another instance of a transfer_info
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| 	 * which is initialised to the values in *ti, and
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| 	 * it's format and rate values can be modified by
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| 	 * the callback if it is necessary to further restrict
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| 	 * the formats that can be used at the moment, for
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| 	 * example when one codec has multiple logical codec
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| 	 * info structs for multiple inputs.
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| 	 */
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| 	int (*usable)(struct codec_info_item *cii,
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| 		      struct transfer_info *ti,
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| 		      struct transfer_info *out);
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| 
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| 	/* called when pcm stream is opened, probably not implemented
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| 	 * most of the time since it isn't too useful */
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| 	int (*open)(struct codec_info_item *cii,
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| 		    struct snd_pcm_substream *substream);
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| 
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| 	/* called when the pcm stream is closed, at this point
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| 	 * the user choices can all be unlocked (see below) */
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| 	int (*close)(struct codec_info_item *cii,
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| 		     struct snd_pcm_substream *substream);
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| 
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| 	/* if the codec must forbid some user choices because
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| 	 * they are not valid with the substream/transfer info,
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| 	 * it must do so here. Example: no digital output for
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| 	 * incompatible framerate, say 8KHz, on Onyx.
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| 	 * If the selected stuff in the substream is NOT
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| 	 * compatible, you have to reject this call! */
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| 	int (*prepare)(struct codec_info_item *cii,
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| 		       struct bus_info *bi,
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| 		       struct snd_pcm_substream *substream);
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| 
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| 	/* start() is called before data is pushed to the codec.
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| 	 * Note that start() must be atomic! */
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| 	int (*start)(struct codec_info_item *cii,
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| 		     struct snd_pcm_substream *substream);
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| 
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| 	/* stop() is called after data is no longer pushed to the codec.
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| 	 * Note that stop() must be atomic! */
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| 	int (*stop)(struct codec_info_item *cii,
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| 		    struct snd_pcm_substream *substream);
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| 
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| 	int (*suspend)(struct codec_info_item *cii, pm_message_t state);
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| 	int (*resume)(struct codec_info_item *cii);
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| };
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| 
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| /* information on a soundbus device */
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| struct soundbus_dev {
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| 	/* the bus it belongs to */
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| 	struct list_head onbuslist;
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| 
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| 	/* the of device it represents */
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| 	struct platform_device ofdev;
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| 
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| 	/* what modules go by */
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| 	char modalias[32];
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| 
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| 	/* These fields must be before attach_codec can be called.
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| 	 * They should be set by the owner of the alsa card object
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| 	 * that is needed, and whoever sets them must make sure
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| 	 * that they are unique within that alsa card object. */
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| 	char *pcmname;
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| 	int pcmid;
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| 
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| 	/* this is assigned by the soundbus provider in attach_codec */
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| 	struct snd_pcm *pcm;
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| 
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| 	/* operations */
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| 	/* attach a codec to this soundbus, give the alsa
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| 	 * card object the PCMs for this soundbus should be in.
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| 	 * The 'data' pointer must be unique, it is used as the
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| 	 * key for detach_codec(). */
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| 	int (*attach_codec)(struct soundbus_dev *dev, struct snd_card *card,
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| 			    struct codec_info *ci, void *data);
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| 	void (*detach_codec)(struct soundbus_dev *dev, void *data);
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| 	/* TODO: suspend/resume */
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| 
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| 	/* private for the soundbus provider */
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| 	struct list_head codec_list;
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| 	u32 have_out:1, have_in:1;
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| };
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| #define to_soundbus_device(d) container_of(d, struct soundbus_dev, ofdev.dev)
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| #define of_to_soundbus_device(d) container_of(d, struct soundbus_dev, ofdev)
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| 
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| extern int soundbus_add_one(struct soundbus_dev *dev);
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| extern void soundbus_remove_one(struct soundbus_dev *dev);
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| 
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| extern struct soundbus_dev *soundbus_dev_get(struct soundbus_dev *dev);
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| extern void soundbus_dev_put(struct soundbus_dev *dev);
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| 
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| struct soundbus_driver {
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| 	char *name;
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| 	struct module *owner;
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| 
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| 	/* we don't implement any matching at all */
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| 
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| 	int	(*probe)(struct soundbus_dev* dev);
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| 	int	(*remove)(struct soundbus_dev* dev);
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| 
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| 	int	(*suspend)(struct soundbus_dev* dev, pm_message_t state);
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| 	int	(*resume)(struct soundbus_dev* dev);
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| 	int	(*shutdown)(struct soundbus_dev* dev);
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| 
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| 	struct device_driver driver;
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| };
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| #define to_soundbus_driver(drv) container_of(drv,struct soundbus_driver, driver)
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| 
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| extern int soundbus_register_driver(struct soundbus_driver *drv);
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| extern void soundbus_unregister_driver(struct soundbus_driver *drv);
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| 
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| extern struct device_attribute soundbus_dev_attrs[];
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| 
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| #endif /* __SOUNDBUS_H */
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