sound/aoa/soundbus/soundbus.h

   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  */
  27 enum 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 */
  36 struct 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
  46 struct 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 */
  56 struct bus_info {
  57         /* see below */
  58         int sysclock_factor;
  59         int bus_factor;
  60 };
  61
  62 /* information on the codec itself, plus function pointers */
  63 struct 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 */
 139 struct 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
 176 extern int soundbus_add_one(struct soundbus_dev *dev);
 177 extern void soundbus_remove_one(struct soundbus_dev *dev);
 178
 179 extern struct soundbus_dev *soundbus_dev_get(struct soundbus_dev *dev);
 180 extern void soundbus_dev_put(struct soundbus_dev *dev);
 181
 182 struct 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     (*shutdown)(struct soundbus_dev* dev);
 192
 193         struct device_driver driver;
 194 };
 195 #define to_soundbus_driver(drv) container_of(drv,struct soundbus_driver, driver)
 196
 197 extern int soundbus_register_driver(struct soundbus_driver *drv);
 198 extern void soundbus_unregister_driver(struct soundbus_driver *drv);
 199
 200 extern struct attribute *soundbus_dev_attrs[];
 201
 202 #endif /* __SOUNDBUS_H */