202 lines · c
1/* SPDX-License-Identifier: GPL-2.0-only */2/*3 * soundbus generic definitions4 *5 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>6 */7#ifndef __SOUNDBUS_H8#define __SOUNDBUS_H9 10#include <linux/platform_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 source17 * while the bus still is.18 * More importantly, while switch from slave to master, you need19 * to turn off the chip's master function first, but then there's20 * no clock for a while and other chips might reset, so we notify21 * their drivers after having switched.22 * The constants here are codec-point of view, so when we switch23 * the soundbus to master we tell the codec we're going to switch24 * and give it CLOCK_SWITCH_PREPARE_SLAVE!25 */26enum 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 */35struct 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 45struct 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 know54 * what we're going to drive the bus with */55struct bus_info {56 /* see below */57 int sysclock_factor;58 int bus_factor;59};60 61/* information on the codec itself, plus function pointers */62struct codec_info {63 /* the module this lives in */64 struct module *owner;65 66 /* supported transfer possibilities, array terminated by67 * formats or rates being 0. */68 struct transfer_info *transfers;69 70 /* Master clock speed factor71 * 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 user87 * opens the pcm device to determine what the88 * 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_info92 * which is initialised to the values in *ti, and93 * it's format and rate values can be modified by94 * the callback if it is necessary to further restrict95 * the formats that can be used at the moment, for96 * example when one codec has multiple logical codec97 * 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 implemented104 * 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 point109 * 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 because114 * they are not valid with the substream/transfer info,115 * it must do so here. Example: no digital output for116 * incompatible framerate, say 8KHz, on Onyx.117 * If the selected stuff in the substream is NOT118 * 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 */138struct 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 object150 * that is needed, and whoever sets them must make sure151 * 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 alsa160 * card object the PCMs for this soundbus should be in.161 * The 'data' pointer must be unique, it is used as the162 * 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 175extern int soundbus_add_one(struct soundbus_dev *dev);176extern void soundbus_remove_one(struct soundbus_dev *dev);177 178extern struct soundbus_dev *soundbus_dev_get(struct soundbus_dev *dev);179extern void soundbus_dev_put(struct soundbus_dev *dev);180 181struct 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 void (*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 196extern int soundbus_register_driver(struct soundbus_driver *drv);197extern void soundbus_unregister_driver(struct soundbus_driver *drv);198 199extern struct attribute *soundbus_dev_attrs[];200 201#endif /* __SOUNDBUS_H */202