sound/aoa/soundbus/soundbus.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * soundbus generic definitions
   4  *
   5  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
   6  */
   7 #ifndef __SOUNDBUS_H
   8 #define __SOUNDBUS_H
   9
  10 #include <linux/of_device.h>
  11 #include <sound/pcm.h>
  12 #include <linux/list.h>
  13
  14
  15 /* When switching from master to slave or the other way around,
  16  * you don't want to have the codec chip acting as clock source
  17  * while the bus still is.
  18  * More importantly, while switch from slave to master, you need
  19  * to turn off the chip's master function first, but then there's
  20  * no clock for a while and other chips might reset, so we notify
  21  * their drivers after having switched.
  22  * The constants here are codec-point of view, so when we switch
  23  * the soundbus to master we tell the codec we're going to switch
  24  * and give it CLOCK_SWITCH_PREPARE_SLAVE!
  25  */
  26 enum clock_switch {
  27         CLOCK_SWITCH_PREPARE_SLAVE,
  28         CLOCK_SWITCH_PREPARE_MASTER,
  29         CLOCK_SWITCH_SLAVE,
  30         CLOCK_SWITCH_MASTER,
  31         CLOCK_SWITCH_NOTIFY,
  32 };
  33
  34 /* information on a transfer the codec can take */
  35 struct transfer_info {
  36         u64 formats;            /* SNDRV_PCM_FMTBIT_* */
  37         unsigned int rates;     /* SNDRV_PCM_RATE_* */
  38         /* flags */
  39         u32 transfer_in:1, /* input = 1, output = 0 */
  40             must_be_clock_source:1;
  41         /* for codecs to distinguish among their TIs */
  42         int tag;
  43 };
  44
  45 struct codec_info_item {
  46         struct codec_info *codec;
  47         void *codec_data;
  48         struct soundbus_dev *sdev;
  49         /* internal, to be used by the soundbus provider */
  50         struct list_head list;
  51 };
  52
  53 /* for prepare, where the codecs need to know
  54  * what we're going to drive the bus with */
  55 struct bus_info {
  56         /* see below */
  57         int sysclock_factor;
  58         int bus_factor;
  59 };
  60
  61 /* information on the codec itself, plus function pointers */
  62 struct codec_info {
  63         /* the module this lives in */
  64         struct module *owner;
  65
  66         /* supported transfer possibilities, array terminated by
  67          * formats or rates being 0. */
  68         struct transfer_info *transfers;
  69
  70         /* Master clock speed factor
  71          * to be used (master clock speed = sysclock_factor * sampling freq)
  72          * Unused if the soundbus provider has no such notion.
  73          */
  74         int sysclock_factor;
  75
  76         /* Bus factor, bus clock speed = bus_factor * sampling freq)
  77          * Unused if the soundbus provider has no such notion.
  78          */
  79         int bus_factor;
  80
  81         /* operations */
  82         /* clock switching, see above */
  83         int (*switch_clock)(struct codec_info_item *cii,
  84                             enum clock_switch clock);
  85
  86         /* called for each transfer_info when the user
  87          * opens the pcm device to determine what the
  88          * hardware can support at this point in time.
  89          * That can depend on other user-switchable controls.
  90          * Return 1 if usable, 0 if not.
  91          * out points to another instance of a transfer_info
  92          * which is initialised to the values in *ti, and
  93          * it's format and rate values can be modified by
  94          * the callback if it is necessary to further restrict
  95          * the formats that can be used at the moment, for
  96          * example when one codec has multiple logical codec
  97          * info structs for multiple inputs.
  98          */
  99         int (*usable)(struct codec_info_item *cii,
 100                       struct transfer_info *ti,
 101                       struct transfer_info *out);
 102
 103         /* called when pcm stream is opened, probably not implemented
 104          * most of the time since it isn't too useful */
 105         int (*open)(struct codec_info_item *cii,
 106                     struct snd_pcm_substream *substream);
 107
 108         /* called when the pcm stream is closed, at this point
 109          * the user choices can all be unlocked (see below) */
 110         int (*close)(struct codec_info_item *cii,
 111                      struct snd_pcm_substream *substream);
 112
 113         /* if the codec must forbid some user choices because
 114          * they are not valid with the substream/transfer info,
 115          * it must do so here. Example: no digital output for
 116          * incompatible framerate, say 8KHz, on Onyx.
 117          * If the selected stuff in the substream is NOT
 118          * compatible, you have to reject this call! */
 119         int (*prepare)(struct codec_info_item *cii,
 120                        struct bus_info *bi,
 121                        struct snd_pcm_substream *substream);
 122
 123         /* start() is called before data is pushed to the codec.
 124          * Note that start() must be atomic! */
 125         int (*start)(struct codec_info_item *cii,
 126                      struct snd_pcm_substream *substream);
 127
 128         /* stop() is called after data is no longer pushed to the codec.
 129          * Note that stop() must be atomic! */
 130         int (*stop)(struct codec_info_item *cii,
 131                     struct snd_pcm_substream *substream);
 132
 133         int (*suspend)(struct codec_info_item *cii, pm_message_t state);
 134         int (*resume)(struct codec_info_item *cii);
 135 };
 136
 137 /* information on a soundbus device */
 138 struct soundbus_dev {
 139         /* the bus it belongs to */
 140         struct list_head onbuslist;
 141
 142         /* the of device it represents */
 143         struct platform_device ofdev;
 144
 145         /* what modules go by */
 146         char modalias[32];
 147
 148         /* These fields must be before attach_codec can be called.
 149          * They should be set by the owner of the alsa card object
 150          * that is needed, and whoever sets them must make sure
 151          * that they are unique within that alsa card object. */
 152         char *pcmname;
 153         int pcmid;
 154
 155         /* this is assigned by the soundbus provider in attach_codec */
 156         struct snd_pcm *pcm;
 157
 158         /* operations */
 159         /* attach a codec to this soundbus, give the alsa
 160          * card object the PCMs for this soundbus should be in.
 161          * The 'data' pointer must be unique, it is used as the
 162          * key for detach_codec(). */
 163         int (*attach_codec)(struct soundbus_dev *dev, struct snd_card *card,
 164                             struct codec_info *ci, void *data);
 165         void (*detach_codec)(struct soundbus_dev *dev, void *data);
 166         /* TODO: suspend/resume */
 167
 168         /* private for the soundbus provider */
 169         struct list_head codec_list;
 170         u32 have_out:1, have_in:1;
 171 };
 172 #define to_soundbus_device(d) container_of(d, struct soundbus_dev, ofdev.dev)
 173 #define of_to_soundbus_device(d) container_of(d, struct soundbus_dev, ofdev)
 174
 175 extern int soundbus_add_one(struct soundbus_dev *dev);
 176 extern void soundbus_remove_one(struct soundbus_dev *dev);
 177
 178 extern struct soundbus_dev *soundbus_dev_get(struct soundbus_dev *dev);
 179 extern void soundbus_dev_put(struct soundbus_dev *dev);
 180
 181 struct soundbus_driver {
 182         char *name;
 183         struct module *owner;
 184
 185         /* we don't implement any matching at all */
 186
 187         int     (*probe)(struct soundbus_dev* dev);
 188         int     (*remove)(struct soundbus_dev* dev);
 189
 190         int     (*shutdown)(struct soundbus_dev* dev);
 191
 192         struct device_driver driver;
 193 };
 194 #define to_soundbus_driver(drv) container_of(drv,struct soundbus_driver, driver)
 195
 196 extern int soundbus_register_driver(struct soundbus_driver *drv);
 197 extern void soundbus_unregister_driver(struct soundbus_driver *drv);
 198
 199 extern struct attribute *soundbus_dev_attrs[];
 200
 201 #endif /* __SOUNDBUS_H */