linux/sound/aoa/soundbus/soundbus.h
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   1/*
   2 * soundbus generic definitions
   3 *
   4 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
   5 *
   6 * GPL v2, can be found in COPYING.
   7 */
   8#ifndef __SOUNDBUS_H
   9#define __SOUNDBUS_H
  10
  11#include <linux/of_device.h>
  12#include <sound/pcm.h>
  13#include <linux/list.h>
  14
  15
  16/* When switching from master to slave or the other way around,
  17 * you don't want to have the codec chip acting as clock source
  18 * while the bus still is.
  19 * More importantly, while switch from slave to master, you need
  20 * to turn off the chip's master function first, but then there's
  21 * no clock for a while and other chips might reset, so we notify
  22 * their drivers after having switched.
  23 * The constants here are codec-point of view, so when we switch
  24 * the soundbus to master we tell the codec we're going to switch
  25 * and give it CLOCK_SWITCH_PREPARE_SLAVE!
  26 */
  27enum clock_switch {
  28        CLOCK_SWITCH_PREPARE_SLAVE,
  29        CLOCK_SWITCH_PREPARE_MASTER,
  30        CLOCK_SWITCH_SLAVE,
  31        CLOCK_SWITCH_MASTER,
  32        CLOCK_SWITCH_NOTIFY,
  33};
  34
  35/* information on a transfer the codec can take */
  36struct transfer_info {
  37        u64 formats;            /* SNDRV_PCM_FMTBIT_* */
  38        unsigned int rates;     /* SNDRV_PCM_RATE_* */
  39        /* flags */
  40        u32 transfer_in:1, /* input = 1, output = 0 */
  41            must_be_clock_source:1;
  42        /* for codecs to distinguish among their TIs */
  43        int tag;
  44};
  45
  46struct codec_info_item {
  47        struct codec_info *codec;
  48        void *codec_data;
  49        struct soundbus_dev *sdev;
  50        /* internal, to be used by the soundbus provider */
  51        struct list_head list;
  52};
  53
  54/* for prepare, where the codecs need to know
  55 * what we're going to drive the bus with */
  56struct bus_info {
  57        /* see below */
  58        int sysclock_factor;
  59        int bus_factor;
  60};
  61
  62/* information on the codec itself, plus function pointers */
  63struct codec_info {
  64        /* the module this lives in */
  65        struct module *owner;
  66
  67        /* supported transfer possibilities, array terminated by
  68         * formats or rates being 0. */
  69        struct transfer_info *transfers;
  70
  71        /* Master clock speed factor
  72         * to be used (master clock speed = sysclock_factor * sampling freq)
  73         * Unused if the soundbus provider has no such notion.
  74         */
  75        int sysclock_factor;
  76
  77        /* Bus factor, bus clock speed = bus_factor * sampling freq)
  78         * Unused if the soundbus provider has no such notion.
  79         */
  80        int bus_factor;
  81
  82        /* operations */
  83        /* clock switching, see above */
  84        int (*switch_clock)(struct codec_info_item *cii,
  85                            enum clock_switch clock);
  86
  87        /* called for each transfer_info when the user
  88         * opens the pcm device to determine what the
  89         * hardware can support at this point in time.
  90         * That can depend on other user-switchable controls.
  91         * Return 1 if usable, 0 if not.
  92         * out points to another instance of a transfer_info
  93         * which is initialised to the values in *ti, and
  94         * it's format and rate values can be modified by
  95         * the callback if it is necessary to further restrict
  96         * the formats that can be used at the moment, for
  97         * example when one codec has multiple logical codec
  98         * info structs for multiple inputs.
  99         */
 100        int (*usable)(struct codec_info_item *cii,
 101                      struct transfer_info *ti,
 102                      struct transfer_info *out);
 103
 104        /* called when pcm stream is opened, probably not implemented
 105         * most of the time since it isn't too useful */
 106        int (*open)(struct codec_info_item *cii,
 107                    struct snd_pcm_substream *substream);
 108
 109        /* called when the pcm stream is closed, at this point
 110         * the user choices can all be unlocked (see below) */
 111        int (*close)(struct codec_info_item *cii,
 112                     struct snd_pcm_substream *substream);
 113
 114        /* if the codec must forbid some user choices because
 115         * they are not valid with the substream/transfer info,
 116         * it must do so here. Example: no digital output for
 117         * incompatible framerate, say 8KHz, on Onyx.
 118         * If the selected stuff in the substream is NOT
 119         * compatible, you have to reject this call! */
 120        int (*prepare)(struct codec_info_item *cii,
 121                       struct bus_info *bi,
 122                       struct snd_pcm_substream *substream);
 123
 124        /* start() is called before data is pushed to the codec.
 125         * Note that start() must be atomic! */
 126        int (*start)(struct codec_info_item *cii,
 127                     struct snd_pcm_substream *substream);
 128
 129        /* stop() is called after data is no longer pushed to the codec.
 130         * Note that stop() must be atomic! */
 131        int (*stop)(struct codec_info_item *cii,
 132                    struct snd_pcm_substream *substream);
 133
 134        int (*suspend)(struct codec_info_item *cii, pm_message_t state);
 135        int (*resume)(struct codec_info_item *cii);
 136};
 137
 138/* information on a soundbus device */
 139struct soundbus_dev {
 140        /* the bus it belongs to */
 141        struct list_head onbuslist;
 142
 143        /* the of device it represents */
 144        struct platform_device ofdev;
 145
 146        /* what modules go by */
 147        char modalias[32];
 148
 149        /* These fields must be before attach_codec can be called.
 150         * They should be set by the owner of the alsa card object
 151         * that is needed, and whoever sets them must make sure
 152         * that they are unique within that alsa card object. */
 153        char *pcmname;
 154        int pcmid;
 155
 156        /* this is assigned by the soundbus provider in attach_codec */
 157        struct snd_pcm *pcm;
 158
 159        /* operations */
 160        /* attach a codec to this soundbus, give the alsa
 161         * card object the PCMs for this soundbus should be in.
 162         * The 'data' pointer must be unique, it is used as the
 163         * key for detach_codec(). */
 164        int (*attach_codec)(struct soundbus_dev *dev, struct snd_card *card,
 165                            struct codec_info *ci, void *data);
 166        void (*detach_codec)(struct soundbus_dev *dev, void *data);
 167        /* TODO: suspend/resume */
 168
 169        /* private for the soundbus provider */
 170        struct list_head codec_list;
 171        u32 have_out:1, have_in:1;
 172};
 173#define to_soundbus_device(d) container_of(d, struct soundbus_dev, ofdev.dev)
 174#define of_to_soundbus_device(d) container_of(d, struct soundbus_dev, ofdev)
 175
 176extern int soundbus_add_one(struct soundbus_dev *dev);
 177extern void soundbus_remove_one(struct soundbus_dev *dev);
 178
 179extern struct soundbus_dev *soundbus_dev_get(struct soundbus_dev *dev);
 180extern void soundbus_dev_put(struct soundbus_dev *dev);
 181
 182struct soundbus_driver {
 183        char *name;
 184        struct module *owner;
 185
 186        /* we don't implement any matching at all */
 187
 188        int     (*probe)(struct soundbus_dev* dev);
 189        int     (*remove)(struct soundbus_dev* dev);
 190
 191        int     (*suspend)(struct soundbus_dev* dev, pm_message_t state);
 192        int     (*resume)(struct soundbus_dev* dev);
 193        int     (*shutdown)(struct soundbus_dev* dev);
 194
 195        struct device_driver driver;
 196};
 197#define to_soundbus_driver(drv) container_of(drv,struct soundbus_driver, driver)
 198
 199extern int soundbus_register_driver(struct soundbus_driver *drv);
 200extern void soundbus_unregister_driver(struct soundbus_driver *drv);
 201
 202extern struct device_attribute soundbus_dev_attrs[];
 203
 204#endif /* __SOUNDBUS_H */
 205