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diff --git a/documentation/content/en/books/arch-handbook/sound/_index.po b/documentation/content/en/books/arch-handbook/sound/_index.po new file mode 100644 index 0000000000..dfbbf4a40a --- /dev/null +++ b/documentation/content/en/books/arch-handbook/sound/_index.po @@ -0,0 +1,855 @@ +# SOME DESCRIPTIVE TITLE +# Copyright (C) YEAR The FreeBSD Project +# This file is distributed under the same license as the FreeBSD Documentation package. +# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. +# +#, fuzzy +msgid "" +msgstr "" +"Project-Id-Version: FreeBSD Documentation VERSION\n" +"POT-Creation-Date: 2022-02-01 09:20-0300\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <LL@li.org>\n" +"Language: \n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#. type: YAML Front Matter: description +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:1 +#, no-wrap +msgid "FreeBSD Sound Subsystem" +msgstr "" + +#. type: YAML Front Matter: title +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:1 +#, no-wrap +msgid "Chapter 15. Sound Subsystem" +msgstr "" + +#. type: Title = +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:13 +#, no-wrap +msgid "Sound Subsystem" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:51 +#, no-wrap +msgid "Introduction" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:54 +msgid "" +"The FreeBSD sound subsystem cleanly separates generic sound handling issues " +"from device-specific ones. This makes it easier to add support for new " +"hardware." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:56 +msgid "" +"The man:pcm[4] framework is the central piece of the sound subsystem. It " +"mainly implements the following elements:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:58 +msgid "" +"A system call interface (read, write, ioctls) to digitized sound and mixer " +"functions. The ioctl command set is compatible with the legacy _OSS_ or " +"_Voxware_ interface, allowing common multimedia applications to be ported " +"without modification." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:59 +msgid "" +"Common code for processing sound data (format conversions, virtual channels)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:60 +msgid "" +"A uniform software interface to hardware-specific audio interface modules." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:61 +msgid "" +"Additional support for some common hardware interfaces (ac97), or shared " +"hardware-specific code (ex: ISA DMA routines)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:63 +msgid "" +"The support for specific sound cards is implemented by hardware-specific " +"drivers, which provide channel and mixer interfaces to plug into the generic " +"[.filename]#pcm# code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:65 +msgid "" +"In this chapter, the term [.filename]#pcm# will refer to the central, common " +"part of the sound driver, as opposed to the hardware-specific modules." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:67 +msgid "" +"The prospective driver writer will of course want to start from an existing " +"module and use the code as the ultimate reference. But, while the sound code " +"is nice and clean, it is also mostly devoid of comments. This document tries " +"to give an overview of the framework interface and answer some questions " +"that may arise while adapting the existing code." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:69 +msgid "" +"As an alternative, or in addition to starting from a working example, you " +"can find a commented driver template at https://people.FreeBSD.org/~cg/" +"template.c[ https://people.FreeBSD.org/~cg/template.c]" +msgstr "" + +#. type: Title == +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:71 +#, no-wrap +msgid "Files" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:74 +msgid "" +"All the relevant code lives in [.filename]#/usr/src/sys/dev/sound/#, except " +"for the public ioctl interface definitions, found in [.filename]#/usr/src/" +"sys/sys/soundcard.h#" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:76 +msgid "" +"Under [.filename]#/usr/src/sys/dev/sound/#, the [.filename]#pcm/# directory " +"holds the central code, while the [.filename]#pci/#, [.filename]#isa/# and [." +"filename]#usb/# directories have the drivers for PCI and ISA boards, and for " +"USB audio devices." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:78 +#, no-wrap +msgid "Probing, Attaching, etc." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:81 +msgid "" +"Sound drivers probe and attach in almost the same way as any hardware driver " +"module. You might want to look at the crossref:isa-driver[isa-driver,ISA] or " +"crossref:pci[pci,PCI] specific sections of the handbook for more information." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:83 +msgid "However, sound drivers differ in some ways:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:85 +msgid "" +"They declare themselves as [.filename]#pcm# class devices, with a `struct " +"snddev_info` device private structure:" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:93 +#, no-wrap +msgid "" +" static driver_t xxx_driver = {\n" +" \"pcm\",\n" +" xxx_methods,\n" +" sizeof(struct snddev_info)\n" +" };\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:96 +#, no-wrap +msgid "" +" DRIVER_MODULE(snd_xxxpci, pci, xxx_driver, pcm_devclass, 0, 0);\n" +" MODULE_DEPEND(snd_xxxpci, snd_pcm, PCM_MINVER, PCM_PREFVER,PCM_MAXVER);\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:99 +msgid "" +"Most sound drivers need to store additional private information about their " +"device. A private data structure is usually allocated in the attach routine. " +"Its address is passed to [.filename]#pcm# by the calls to `pcm_register()` " +"and `mixer_init()`. [.filename]#pcm# later passes back this address as a " +"parameter in calls to the sound driver interfaces." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:100 +msgid "" +"The sound driver attach routine should declare its MIXER or AC97 interface " +"to [.filename]#pcm# by calling `mixer_init()`. For a MIXER interface, this " +"causes in turn a call to <<xxxmixer-init,`xxxmixer_init()`>>." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:101 +msgid "" +"The sound driver attach routine declares its general CHANNEL configuration " +"to [.filename]#pcm# by calling `pcm_register(dev, sc, nplay, nrec)`, where " +"`sc` is the address for the device data structure, used in further calls " +"from [.filename]#pcm#, and `nplay` and `nrec` are the number of play and " +"record channels." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:102 +msgid "" +"The sound driver attach routine declares each of its channel objects by " +"calls to `pcm_addchan()`. This sets up the channel glue in [.filename]#pcm# " +"and causes in turn a call to <<xxxchannel-init,`xxxchannel_init()`>>." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:103 +msgid "" +"The sound driver detach routine should call `pcm_unregister()` before " +"releasing its resources." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:105 +msgid "There are two possible methods to handle non-PnP devices:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:107 +msgid "" +"Use a `device_identify()` method (example: [.filename]#sound/isa/es1888.c#). " +"The `device_identify()` method probes for the hardware at known addresses " +"and, if it finds a supported device, creates a new pcm device which is then " +"passed to probe/attach." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:108 +msgid "" +"Use a custom kernel configuration with appropriate hints for pcm devices " +"(example: [.filename]#sound/isa/mss.c#)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:110 +msgid "" +"[.filename]#pcm# drivers should implement `device_suspend`, `device_resume` " +"and `device_shutdown` routines, so that power management and module " +"unloading function correctly." +msgstr "" + +#. type: Title == +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:112 +#, no-wrap +msgid "Interfaces" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:115 +msgid "" +"The interface between the [.filename]#pcm# core and the sound drivers is " +"defined in terms of <<kernel-objects,kernel objects>>." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:117 +msgid "" +"There are two main interfaces that a sound driver will usually provide: " +"_CHANNEL_ and either _MIXER_ or _AC97_." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:119 +msgid "" +"The _AC97_ interface is a very small hardware access (register read/write) " +"interface, implemented by drivers for hardware with an AC97 codec. In this " +"case, the actual MIXER interface is provided by the shared AC97 code in [." +"filename]#pcm#." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:120 +#, no-wrap +msgid "The CHANNEL Interface" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:122 +#, no-wrap +msgid "Common Notes for Function Parameters" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:125 +msgid "" +"Sound drivers usually have a private data structure to describe their " +"device, and one structure for each play and record data channel that it " +"supports." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:127 +msgid "" +"For all CHANNEL interface functions, the first parameter is an opaque " +"pointer." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:129 +msgid "" +"The second parameter is a pointer to the private channel data structure, " +"except for `channel_init()` which has a pointer to the private device " +"structure (and returns the channel pointer for further use by [." +"filename]#pcm#)." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:130 +#, no-wrap +msgid "Overview of Data Transfer Operations" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:133 +msgid "" +"For sound data transfers, the [.filename]#pcm# core and the sound drivers " +"communicate through a shared memory area, described by a `struct snd_dbuf`." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:135 +msgid "" +"`struct snd_dbuf` is private to [.filename]#pcm#, and sound drivers obtain " +"values of interest by calls to accessor functions (`sndbuf_getxxx()`)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:137 +msgid "" +"The shared memory area has a size of `sndbuf_getsize()` and is divided into " +"fixed size blocks of `sndbuf_getblksz()` bytes." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:139 +msgid "" +"When playing, the general transfer mechanism is as follows (reverse the idea " +"for recording):" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:141 +msgid "" +"[.filename]#pcm# initially fills up the buffer, then calls the sound " +"driver's <<channel-trigger,`xxxchannel_trigger()`>> function with a " +"parameter of PCMTRIG_START." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:142 +msgid "" +"The sound driver then arranges to repeatedly transfer the whole memory area " +"(`sndbuf_getbuf()`, `sndbuf_getsize()`) to the device, in blocks of " +"`sndbuf_getblksz()` bytes. It calls back the `chn_intr()`[.filename]#pcm# " +"function for each transferred block (this will typically happen at interrupt " +"time)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:143 +msgid "" +"`chn_intr()` arranges to copy new data to the area that was transferred to " +"the device (now free), and make appropriate updates to the `snd_dbuf` " +"structure." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:145 +#, no-wrap +msgid "channel_init" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:148 +msgid "" +"`xxxchannel_init()` is called to initialize each of the play or record " +"channels. The calls are initiated from the sound driver attach routine. (See " +"the <<pcm-probe-and-attach,probe and attach section>>)." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:160 +#, no-wrap +msgid "" +" static void *\n" +" xxxchannel_init(kobj_t obj, void *data,\n" +" struct snd_dbuf *b, struct pcm_channel *c, int dir) <.>\n" +" {\n" +" struct xxx_info *sc = data;\n" +" struct xxx_chinfo *ch;\n" +" ...\n" +" return ch; <.>\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:163 +msgid "" +"`b` is the address for the channel `struct snd_dbuf`. It should be " +"initialized in the function by calling `sndbuf_alloc()`. The buffer size to " +"use is normally a small multiple of the 'typical' unit transfer size for " +"your device.`c` is the [.filename]#pcm# channel control structure pointer. " +"This is an opaque object. The function should store it in the local channel " +"structure, to be used in later calls to [.filename]#pcm# (ie: `chn_intr(c)`)." +"`dir` indicates the channel direction (`PCMDIR_PLAY` or `PCMDIR_REC`)." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:165 +msgid "" +"The function should return a pointer to the private area used to control " +"this channel. This will be passed as a parameter to other channel interface " +"calls." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:166 +#, no-wrap +msgid "channel_setformat" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:169 +msgid "" +"`xxxchannel_setformat()` should set up the hardware for the specified " +"channel for the specified sound format." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:179 +#, no-wrap +msgid "" +" static int\n" +" xxxchannel_setformat(kobj_t obj, void *data, u_int32_t format) <.>\n" +" {\n" +" struct xxx_chinfo *ch = data;\n" +" ...\n" +" return 0;\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:182 +msgid "" +"`format` is specified as an `AFMT_XXX value` ([.filename]#soundcard.h#)." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:183 +#, no-wrap +msgid "channel_setspeed" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:186 +msgid "" +"`xxxchannel_setspeed()` sets up the channel hardware for the specified " +"sampling speed, and returns the possibly adjusted speed." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:196 +#, no-wrap +msgid "" +" static int\n" +" xxxchannel_setspeed(kobj_t obj, void *data, u_int32_t speed)\n" +" {\n" +" struct xxx_chinfo *ch = data;\n" +" ...\n" +" return speed;\n" +" }\n" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:198 +#, no-wrap +msgid "channel_setblocksize" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:201 +msgid "" +"`xxxchannel_setblocksize()` sets the block size, which is the size of unit " +"transactions between [.filename]#pcm# and the sound driver, and between the " +"sound driver and the device. Typically, this would be the number of bytes " +"transferred before an interrupt occurs. During a transfer, the sound driver " +"should call [.filename]#pcm#'s `chn_intr()` every time this size has been " +"transferred." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:203 +msgid "" +"Most sound drivers only take note of the block size here, to be used when an " +"actual transfer will be started." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:213 +#, no-wrap +msgid "" +" static int\n" +" xxxchannel_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)\n" +" {\n" +" struct xxx_chinfo *ch = data;\n" +" ...\n" +" return blocksize; <.>\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:216 +msgid "" +"The function returns the possibly adjusted block size. In case the block " +"size is indeed changed, `sndbuf_resize()` should be called to adjust the " +"buffer." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:218 +#, no-wrap +msgid "channel_trigger" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:221 +msgid "" +"`xxxchannel_trigger()` is called by [.filename]#pcm# to control data " +"transfer operations in the driver." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:231 +#, no-wrap +msgid "" +" static int\n" +" xxxchannel_trigger(kobj_t obj, void *data, int go) <.>\n" +" {\n" +" struct xxx_chinfo *ch = data;\n" +" ...\n" +" return 0;\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:234 +msgid "`go` defines the action for the current call. The possible values are:" +msgstr "" + +#. type: delimited block = 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:238 +msgid "" +"If the driver uses ISA DMA, `sndbuf_isadma()` should be called before " +"performing actions on the device, and will take care of the DMA chip side of " +"things." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:240 +#, no-wrap +msgid "channel_getptr" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:243 +msgid "" +"`xxxchannel_getptr()` returns the current offset in the transfer buffer. " +"This will typically be called by `chn_intr()`, and this is how [." +"filename]#pcm# knows where it can transfer new data." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:244 +#, no-wrap +msgid "channel_free" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:247 +msgid "" +"`xxxchannel_free()` is called to free up channel resources, for example when " +"the driver is unloaded, and should be implemented if the channel data " +"structures are dynamically allocated or if `sndbuf_alloc()` was not used for " +"buffer allocation." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:248 +#, no-wrap +msgid "channel_getcaps" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:257 +#, no-wrap +msgid "" +" struct pcmchan_caps *\n" +" xxxchannel_getcaps(kobj_t obj, void *data)\n" +" {\n" +" return &xxx_caps; <.>\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:260 +msgid "" +"The routine returns a pointer to a (usually statically-defined) " +"`pcmchan_caps` structure (defined in [.filename]#sound/pcm/channel.h#. The " +"structure holds the minimum and maximum sampling frequencies, and the " +"accepted sound formats. Look at any sound driver for an example." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:261 +#, no-wrap +msgid "More Functions" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:264 +msgid "" +"`channel_reset()`, `channel_resetdone()`, and `channel_notify()` are for " +"special purposes and should not be implemented in a driver without " +"discussing it on the {freebsd-multimedia}." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:266 +msgid "`channel_setdir()` is deprecated." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:267 +#, no-wrap +msgid "The MIXER Interface" +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:270 +#, no-wrap +msgid "mixer_init" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:273 +msgid "" +"`xxxmixer_init()` initializes the hardware and tells [.filename]#pcm# what " +"mixer devices are available for playing and recording" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:281 +#, no-wrap +msgid "" +" static int\n" +" xxxmixer_init(struct snd_mixer *m)\n" +" {\n" +" struct xxx_info *sc = mix_getdevinfo(m);\n" +" u_int32_t v;\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:283 +#, no-wrap +msgid " [Initialize hardware]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:288 +#, no-wrap +msgid "" +" [Set appropriate bits in v for play mixers] <.>\n" +" mix_setdevs(m, v);\n" +" [Set appropriate bits in v for record mixers]\n" +" mix_setrecdevs(m, v)\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:291 +#, no-wrap +msgid "" +" return 0;\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:294 +msgid "" +"Set bits in an integer value and call `mix_setdevs()` and `mix_setrecdevs()` " +"to tell [.filename]#pcm# what devices exist." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:296 +msgid "" +"Mixer bits definitions can be found in [.filename]#soundcard.h# " +"(`SOUND_MASK_XXX` values and `SOUND_MIXER_XXX` bit shifts)." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:297 +#, no-wrap +msgid "mixer_set" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:300 +msgid "`xxxmixer_set()` sets the volume level for one mixer device." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:311 +#, no-wrap +msgid "" +" static int\n" +" xxxmixer_set(struct snd_mixer *m, unsigned dev,\n" +" unsigned left, unsigned right) <.>\n" +" {\n" +" struct sc_info *sc = mix_getdevinfo(m);\n" +" [set volume level]\n" +" return left | (right << 8); <.>\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:314 +msgid "" +"The device is specified as a `SOUND_MIXER_XXX` value. The volume values are " +"specified in range [0-100]. A value of zero should mute the device." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:315 +msgid "" +"As the hardware levels probably will not match the input scale, and some " +"rounding will occur, the routine returns the actual level values (in range " +"0-100) as shown." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:316 +#, no-wrap +msgid "mixer_setrecsrc" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:319 +msgid "`xxxmixer_setrecsrc()` sets the recording source device." +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:326 +#, no-wrap +msgid "" +" static int\n" +" xxxmixer_setrecsrc(struct snd_mixer *m, u_int32_t src) <.>\n" +" {\n" +" struct xxx_info *sc = mix_getdevinfo(m);\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:328 +#, no-wrap +msgid " [look for non zero bit(s) in src, set up hardware]\n" +msgstr "" + +#. type: delimited block . 4 +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:332 +#, no-wrap +msgid "" +" [update src to reflect actual action]\n" +" return src; <.>\n" +" }\n" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:335 +msgid "The desired recording devices are specified as a bit field" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:336 +msgid "" +"The actual devices set for recording are returned. Some drivers can only set " +"one device for recording. The function should return -1 if an error occurs." +msgstr "" + +#. type: Title ==== +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:337 +#, no-wrap +msgid "mixer_uninit, mixer_reinit" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:340 +msgid "" +"`xxxmixer_uninit()` should ensure that all sound is muted and if possible " +"mixer hardware should be powered down." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:342 +msgid "" +"`xxxmixer_reinit()` should ensure that the mixer hardware is powered up and " +"any settings not controlled by `mixer_set()` or `mixer_setrecsrc()` are " +"restored." +msgstr "" + +#. type: Title === +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:343 +#, no-wrap +msgid "The AC97 Interface" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:346 +msgid "" +"The _AC97_ interface is implemented by drivers with an AC97 codec. It only " +"has three methods:" +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:348 +msgid "`xxxac97_init()` returns the number of ac97 codecs found." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:349 +msgid "`ac97_read()` and `ac97_write()` read or write a specified register." +msgstr "" + +#. type: Plain text +#: documentation/content/en/books/arch-handbook/sound/_index.adoc:350 +msgid "" +"The _AC97_ interface is used by the AC97 code in [.filename]#pcm# to perform " +"higher level operations. Look at [.filename]#sound/pci/maestro3.c# or many " +"others under [.filename]#sound/pci/# for an example." +msgstr "" |