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 */ 203