From c6994e6f067cf0fc4c6cca3d164018b1150916f8 Mon Sep 17 00:00:00 2001 From: Bryan Wu Date: Wed, 3 Jun 2009 09:17:58 -0400 Subject: USB: gadget: add USB Audio Gadget driver Funtions added: - setup all the USB audio class device descriptors - handle class specific setup request - receive data from USB host by ISO transfer - play audio data by ALSA sound card - open and setup playback PCM interface - set default playback PCM parameters - provide playback functions for USB audio driver - provide PCM parameters set/get functions Test on: - Host: Ubuntu 8.10, kernel 2.6.27 - Gadget: EZKIT-BF548 with ASoC AD1980 codec Todo: - add real Mute control code - add real Volume control code - maybe find another way to replace dynamic buffer handling with static buffer allocation - test on Windows system - provide control interface to handle mute/volume control - provide capture interface in the future - test on BF527, other USB device controler and other audio codec Signed-off-by: Bryan Wu Signed-off-by: Mike Frysinger Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/u_audio.c | 319 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 319 insertions(+) create mode 100644 drivers/usb/gadget/u_audio.c (limited to 'drivers/usb/gadget/u_audio.c') diff --git a/drivers/usb/gadget/u_audio.c b/drivers/usb/gadget/u_audio.c new file mode 100644 index 00000000000..0f3d22fc030 --- /dev/null +++ b/drivers/usb/gadget/u_audio.c @@ -0,0 +1,319 @@ +/* + * u_audio.c -- ALSA audio utilities for Gadget stack + * + * Copyright (C) 2008 Bryan Wu + * Copyright (C) 2008 Analog Devices, Inc + * + * Enter bugs at http://blackfin.uclinux.org/ + * + * Licensed under the GPL-2 or later. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "u_audio.h" + +/* + * This component encapsulates the ALSA devices for USB audio gadget + */ + +#define FILE_PCM_PLAYBACK "/dev/snd/pcmC0D0p" +#define FILE_PCM_CAPTURE "/dev/snd/pcmC0D0c" +#define FILE_CONTROL "/dev/snd/controlC0" + +static char *fn_play = FILE_PCM_PLAYBACK; +module_param(fn_play, charp, S_IRUGO); +MODULE_PARM_DESC(fn_play, "Playback PCM device file name"); + +static char *fn_cap = FILE_PCM_CAPTURE; +module_param(fn_cap, charp, S_IRUGO); +MODULE_PARM_DESC(fn_cap, "Capture PCM device file name"); + +static char *fn_cntl = FILE_CONTROL; +module_param(fn_cntl, charp, S_IRUGO); +MODULE_PARM_DESC(fn_cntl, "Control device file name"); + +/*-------------------------------------------------------------------------*/ + +/** + * Some ALSA internal helper functions + */ +static int snd_interval_refine_set(struct snd_interval *i, unsigned int val) +{ + struct snd_interval t; + t.empty = 0; + t.min = t.max = val; + t.openmin = t.openmax = 0; + t.integer = 1; + return snd_interval_refine(i, &t); +} + +static int _snd_pcm_hw_param_set(struct snd_pcm_hw_params *params, + snd_pcm_hw_param_t var, unsigned int val, + int dir) +{ + int changed; + if (hw_is_mask(var)) { + struct snd_mask *m = hw_param_mask(params, var); + if (val == 0 && dir < 0) { + changed = -EINVAL; + snd_mask_none(m); + } else { + if (dir > 0) + val++; + else if (dir < 0) + val--; + changed = snd_mask_refine_set( + hw_param_mask(params, var), val); + } + } else if (hw_is_interval(var)) { + struct snd_interval *i = hw_param_interval(params, var); + if (val == 0 && dir < 0) { + changed = -EINVAL; + snd_interval_none(i); + } else if (dir == 0) + changed = snd_interval_refine_set(i, val); + else { + struct snd_interval t; + t.openmin = 1; + t.openmax = 1; + t.empty = 0; + t.integer = 0; + if (dir < 0) { + t.min = val - 1; + t.max = val; + } else { + t.min = val; + t.max = val+1; + } + changed = snd_interval_refine(i, &t); + } + } else + return -EINVAL; + if (changed) { + params->cmask |= 1 << var; + params->rmask |= 1 << var; + } + return changed; +} +/*-------------------------------------------------------------------------*/ + +/** + * Set default hardware params + */ +static int playback_default_hw_params(struct gaudio_snd_dev *snd) +{ + struct snd_pcm_substream *substream = snd->substream; + struct snd_pcm_hw_params *params; + snd_pcm_sframes_t result; + + /* + * SNDRV_PCM_ACCESS_RW_INTERLEAVED, + * SNDRV_PCM_FORMAT_S16_LE + * CHANNELS: 2 + * RATE: 48000 + */ + snd->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED; + snd->format = SNDRV_PCM_FORMAT_S16_LE; + snd->channels = 2; + snd->rate = 48000; + + params = kzalloc(sizeof(*params), GFP_KERNEL); + if (!params) + return -ENOMEM; + + _snd_pcm_hw_params_any(params); + _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_ACCESS, + snd->access, 0); + _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_FORMAT, + snd->format, 0); + _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_CHANNELS, + snd->channels, 0); + _snd_pcm_hw_param_set(params, SNDRV_PCM_HW_PARAM_RATE, + snd->rate, 0); + + snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL); + snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_HW_PARAMS, params); + + result = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_PREPARE, NULL); + if (result < 0) { + ERROR(snd->card, + "Preparing sound card failed: %d\n", (int)result); + kfree(params); + return result; + } + + /* Store the hardware parameters */ + snd->access = params_access(params); + snd->format = params_format(params); + snd->channels = params_channels(params); + snd->rate = params_rate(params); + + kfree(params); + + INFO(snd->card, + "Hardware params: access %x, format %x, channels %d, rate %d\n", + snd->access, snd->format, snd->channels, snd->rate); + + return 0; +} + +/** + * Playback audio buffer data by ALSA PCM device + */ +static size_t u_audio_playback(struct gaudio *card, void *buf, size_t count) +{ + struct gaudio_snd_dev *snd = &card->playback; + struct snd_pcm_substream *substream = snd->substream; + struct snd_pcm_runtime *runtime = substream->runtime; + mm_segment_t old_fs; + ssize_t result; + snd_pcm_sframes_t frames; + +try_again: + if (runtime->status->state == SNDRV_PCM_STATE_XRUN || + runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) { + result = snd_pcm_kernel_ioctl(substream, + SNDRV_PCM_IOCTL_PREPARE, NULL); + if (result < 0) { + ERROR(card, "Preparing sound card failed: %d\n", + (int)result); + return result; + } + } + + frames = bytes_to_frames(runtime, count); + old_fs = get_fs(); + set_fs(KERNEL_DS); + result = snd_pcm_lib_write(snd->substream, buf, frames); + if (result != frames) { + ERROR(card, "Playback error: %d\n", (int)result); + set_fs(old_fs); + goto try_again; + } + set_fs(old_fs); + + return 0; +} + +static int u_audio_get_playback_channels(struct gaudio *card) +{ + return card->playback.channels; +} + +static int u_audio_get_playback_rate(struct gaudio *card) +{ + return card->playback.rate; +} + +/** + * Open ALSA PCM and control device files + * Initial the PCM or control device + */ +static int gaudio_open_snd_dev(struct gaudio *card) +{ + struct snd_pcm_file *pcm_file; + struct gaudio_snd_dev *snd; + + if (!card) + return -ENODEV; + + /* Open control device */ + snd = &card->control; + snd->filp = filp_open(fn_cntl, O_RDWR, 0); + if (IS_ERR(snd->filp)) { + int ret = PTR_ERR(snd->filp); + ERROR(card, "unable to open sound control device file: %s\n", + fn_cntl); + snd->filp = NULL; + return ret; + } + snd->card = card; + + /* Open PCM playback device and setup substream */ + snd = &card->playback; + snd->filp = filp_open(fn_play, O_WRONLY, 0); + if (IS_ERR(snd->filp)) { + ERROR(card, "No such PCM playback device: %s\n", fn_play); + snd->filp = NULL; + } + pcm_file = snd->filp->private_data; + snd->substream = pcm_file->substream; + snd->card = card; + playback_default_hw_params(snd); + + /* Open PCM capture device and setup substream */ + snd = &card->capture; + snd->filp = filp_open(fn_cap, O_RDONLY, 0); + if (IS_ERR(snd->filp)) { + ERROR(card, "No such PCM capture device: %s\n", fn_cap); + snd->filp = NULL; + } + pcm_file = snd->filp->private_data; + snd->substream = pcm_file->substream; + snd->card = card; + + return 0; +} + +/** + * Close ALSA PCM and control device files + */ +static int gaudio_close_snd_dev(struct gaudio *gau) +{ + struct gaudio_snd_dev *snd; + + /* Close control device */ + snd = &gau->control; + if (!IS_ERR(snd->filp)) + filp_close(snd->filp, current->files); + + /* Close PCM playback device and setup substream */ + snd = &gau->playback; + if (!IS_ERR(snd->filp)) + filp_close(snd->filp, current->files); + + /* Close PCM capture device and setup substream */ + snd = &gau->capture; + if (!IS_ERR(snd->filp)) + filp_close(snd->filp, current->files); + + return 0; +} + +/** + * gaudio_setup - setup ALSA interface and preparing for USB transfer + * + * This sets up PCM, mixer or MIDI ALSA devices fore USB gadget using. + * + * Returns negative errno, or zero on success + */ +int __init gaudio_setup(struct gaudio *card) +{ + int ret; + + ret = gaudio_open_snd_dev(card); + if (ret) + ERROR(card, "we need at least one control device\n"); + + return ret; + +} + +/** + * gaudio_cleanup - remove ALSA device interface + * + * This is called to free all resources allocated by @gaudio_setup(). + */ +void gaudio_cleanup(struct gaudio *card) +{ + if (card) + gaudio_close_snd_dev(card); +} + -- cgit v1.2.3