This file handles all setup of a new snd_card instance with one pcm_substream. It's also responsible for parsing the raw pcm data received in the isoc transfers, and passing it to the alsa buffers.
Signed-off-by: Jon Arne Jørgensen <jona...@jonarne.no> --- drivers/media/usb/smi2021/smi2021_audio.c | 385 ++++++++++++++++++++++++++++++ 1 file changed, 385 insertions(+) create mode 100644 drivers/media/usb/smi2021/smi2021_audio.c diff --git a/drivers/media/usb/smi2021/smi2021_audio.c b/drivers/media/usb/smi2021/smi2021_audio.c new file mode 100644 index 0000000..cd20181 --- /dev/null +++ b/drivers/media/usb/smi2021/smi2021_audio.c @@ -0,0 +1,385 @@ +/******************************************************************************* + * smi2021_audio.c * + * * + * USB Driver for SMI2021 - EasyCap * + * USB ID 1c88:003c * + * * + * ***************************************************************************** + * + * Copyright 2011-2013 Jon Arne Jørgensen + * <jonjon.arnearne--a.t--gmail.com> + * + * Copyright 2011, 2012 Tony Brown, Michal Demin, Jeffry Johnston + * + * This file is part of SMI2021 + * http://code.google.com/p/easycap-somagic-linux/ + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + * + * This driver is heavily influensed by the STK1160 driver. + * Copyright (C) 2012 Ezequiel Garcia + * <elezegarcia--a.t--gmail.com> + * + */ + +#include "smi2021.h" + +static void pcm_buffer_free(struct snd_pcm_substream *substream) +{ + vfree(substream->runtime->dma_area); + substream->runtime->dma_area = NULL; + substream->runtime->dma_bytes = 0; +} + +static int pcm_buffer_alloc(struct snd_pcm_substream *substream, int size) +{ + if (substream->runtime->dma_area) { + if (substream->runtime->dma_bytes > size) + return 0; + pcm_buffer_free(substream); + } + + substream->runtime->dma_area = vmalloc(size); + if (substream->runtime->dma_area == NULL) + return -ENOMEM; + + substream->runtime->dma_bytes = size; + + return 0; +} + +static const struct snd_pcm_hardware smi2021_pcm_hw = { + .info = SNDRV_PCM_INFO_BLOCK_TRANSFER | + SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_BATCH, + + .formats = SNDRV_PCM_FMTBIT_S32_LE, + + .rates = SNDRV_PCM_RATE_48000, + .rate_min = 48000, + .rate_max = 48000, + .channels_min = 2, + .channels_max = 2, + .period_bytes_min = 992, /* 32640 */ /* 15296 */ + .period_bytes_max = 15872, /* 65280 */ + .periods_min = 1, /* 1 */ + .periods_max = 16, /* 2 */ + .buffer_bytes_max = 65280, /* 65280 */ +}; + +static int smi2021_pcm_open(struct snd_pcm_substream *substream) +{ + struct smi2021_dev *dev = snd_pcm_substream_chip(substream); + struct snd_pcm_runtime *runtime = substream->runtime; + int rc; + + rc = snd_pcm_hw_constraint_pow2(runtime, 0, + SNDRV_PCM_HW_PARAM_PERIODS); + if (rc < 0) + return rc; + + dev->pcm_substream = substream; + + runtime->hw = smi2021_pcm_hw; + snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); + + smi2021_dbg("PCM device open!\n"); + + return 0; +} + +static int smi2021_pcm_close(struct snd_pcm_substream *substream) +{ + struct smi2021_dev *dev = snd_pcm_substream_chip(substream); + smi2021_dbg("PCM device closing\n"); + + if (atomic_read(&dev->adev_capturing)) { + atomic_set(&dev->adev_capturing, 0); + schedule_work(&dev->adev_capture_trigger); + } + return 0; + +} + + +static int smi2021_pcm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *hw_params) +{ + int size, rc; + size = params_period_bytes(hw_params) * params_periods(hw_params); + + rc = pcm_buffer_alloc(substream, size); + if (rc < 0) + return rc; + + + return 0; +} + +static int smi2021_pcm_hw_free(struct snd_pcm_substream *substream) +{ + struct smi2021_dev *dev = snd_pcm_substream_chip(substream); + + if (atomic_read(&dev->adev_capturing)) { + atomic_set(&dev->adev_capturing, 0); + schedule_work(&dev->adev_capture_trigger); + } + + pcm_buffer_free(substream); + return 0; +} + +static int smi2021_pcm_prepare(struct snd_pcm_substream *substream) +{ + struct smi2021_dev *dev = snd_pcm_substream_chip(substream); + + dev->pcm_complete_samples = 0; + dev->pcm_read_offset = 0; + dev->pcm_write_ptr = 0; + + return 0; +} + +static void capture_trigger(struct work_struct *work) +{ + struct smi2021_dev *dev = container_of(work, struct smi2021_dev, + adev_capture_trigger); + + if (atomic_read(&dev->adev_capturing)) + smi2021_write_reg(dev, 0, 0x1740, 0x1d); + else + smi2021_write_reg(dev, 0, 0x1740, 0x00); +} + +/* This callback is ATOMIC, must not sleep */ +static int smi2021_pcm_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct smi2021_dev *dev = snd_pcm_substream_chip(substream); + + switch (cmd) { + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + case SNDRV_PCM_TRIGGER_RESUME: + case SNDRV_PCM_TRIGGER_START: + atomic_set(&dev->adev_capturing, 1); + break; + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: + case SNDRV_PCM_TRIGGER_SUSPEND: + case SNDRV_PCM_TRIGGER_STOP: + atomic_set(&dev->adev_capturing, 0); + break; + default: + return -EINVAL; + } + + schedule_work(&dev->adev_capture_trigger); + + return 0; +} + +static snd_pcm_uframes_t smi2021_pcm_pointer( + struct snd_pcm_substream *substream) +{ + struct smi2021_dev *dev = snd_pcm_substream_chip(substream); + return dev->pcm_write_ptr / 8; +} + +static struct page *smi2021_pcm_get_vmalloc_page(struct snd_pcm_substream *subs, + unsigned long offset) +{ + void *pageptr = subs->runtime->dma_area + offset; + + return vmalloc_to_page(pageptr); +} + +static struct snd_pcm_ops smi2021_pcm_ops = { + .open = smi2021_pcm_open, + .close = smi2021_pcm_close, + .ioctl = snd_pcm_lib_ioctl, + .hw_params = smi2021_pcm_hw_params, + .hw_free = smi2021_pcm_hw_free, + .prepare = smi2021_pcm_prepare, + .trigger = smi2021_pcm_trigger, + .pointer = smi2021_pcm_pointer, + .page = smi2021_pcm_get_vmalloc_page, +}; + +int smi2021_snd_register(struct smi2021_dev *dev) +{ + struct snd_card *card; + struct snd_pcm *pcm; + int rc = 0; + + rc = snd_card_create(SNDRV_DEFAULT_IDX1, "smi2021 Audio", THIS_MODULE, + 0, &card); + if (rc < 0) + return rc; + + rc = snd_pcm_new(card, "smi2021 Audio", 0, 0, 1, &pcm); + if (rc < 0) + goto err_free_card; + + snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &smi2021_pcm_ops); + pcm->info_flags = 0; + pcm->private_data = dev; + strcpy(pcm->name, "Somagic smi2021 Capture"); + + strcpy(card->driver, "smi2021-Audio"); + strcpy(card->shortname, "smi2021 Audio"); + strcpy(card->longname, "Somagic smi2021 Audio"); + + INIT_WORK(&dev->adev_capture_trigger, capture_trigger); + + rc = snd_card_register(card); + if (rc < 0) + goto err_free_card; + + dev->snd_card = card; + + return 0; + +err_free_card: + snd_card_free(card); + return rc; +} + +void smi2021_snd_unregister(struct smi2021_dev *dev) +{ + if (!dev) + return; + + if (!dev->snd_card) + return; + + snd_card_free(dev->snd_card); + dev->snd_card = NULL; +} + +void smi2021_audio(struct smi2021_dev *dev, u8 *data, int len) +{ + struct snd_pcm_runtime *runtime; + u8 offset; + int new_offset = 0; + + int skip; + unsigned int stride, oldptr, headptr; + + int diff = 0; + int samples = 0; + bool period_elapsed = false; + + + if (!dev->udev) + return; + + if (atomic_read(&dev->adev_capturing) == 0) + return; + + if (!dev->pcm_substream) + return; + + runtime = dev->pcm_substream->runtime; + if (!runtime || !runtime->dma_area) + return; + + offset = dev->pcm_read_offset; + stride = runtime->frame_bits >> 3; + + if (stride == 0) + return; + + diff = dev->pcm_write_ptr; + + /* Check that the end of the last buffer was correct. + * If not correct, we mark any partial frames in buffer as complete + */ + headptr = dev->pcm_write_ptr - offset - 4; + if (dev->pcm_write_ptr > 10 && runtime->dma_area[headptr] != 0x00) { + skip = stride - (dev->pcm_write_ptr % stride); + snd_pcm_stream_lock(dev->pcm_substream); + dev->pcm_write_ptr += skip; + + if (dev->pcm_write_ptr >= runtime->dma_bytes) + dev->pcm_write_ptr -= runtime->dma_bytes; + + snd_pcm_stream_unlock(dev->pcm_substream); + offset = dev->pcm_read_offset = 0; + } + /* The device is actually sending 24Bit pcm data + * with 0x00 as the header byte before each sample. + * We look for this byte to make sure we did not + * loose any bytes during transfer. + */ + while (len > stride && (data[offset] != 0x00 || + data[offset + (stride / 2)] != 0x00)) { + new_offset++; + data++; + len--; + } + + if (len <= stride) { + /* We exhausted the buffer looking for 0x00 */ + dev->pcm_read_offset = 0; + return; + } + if (new_offset != 0) { + /* This buffer can not be appended to the current buffer, + * so we mark any partial frames in the buffer as complete. + */ + skip = stride - (dev->pcm_write_ptr % stride); + snd_pcm_stream_lock(dev->pcm_substream); + dev->pcm_write_ptr += skip; + + if (dev->pcm_write_ptr >= runtime->dma_bytes) + dev->pcm_write_ptr -= runtime->dma_bytes; + + snd_pcm_stream_unlock(dev->pcm_substream); + + offset = dev->pcm_read_offset = new_offset % (stride / 2); + + } + + oldptr = dev->pcm_write_ptr; + if (oldptr + len >= runtime->dma_bytes) { + unsigned int cnt = runtime->dma_bytes - oldptr; + memcpy(runtime->dma_area + oldptr, data, cnt); + memcpy(runtime->dma_area, data + cnt, len - cnt); + } else { + memcpy(runtime->dma_area + oldptr, data, len); + } + + snd_pcm_stream_lock(dev->pcm_substream); + dev->pcm_write_ptr += len; + + if (dev->pcm_write_ptr >= runtime->dma_bytes) + dev->pcm_write_ptr -= runtime->dma_bytes; + + samples = dev->pcm_write_ptr - diff; + if (samples < 0) + samples += runtime->dma_bytes; + + samples /= (stride / 2); + + dev->pcm_complete_samples += samples; + if (dev->pcm_complete_samples / 2 >= runtime->period_size) { + dev->pcm_complete_samples -= runtime->period_size * 2; + period_elapsed = true; + } + snd_pcm_stream_unlock(dev->pcm_substream); + + if (period_elapsed) + snd_pcm_period_elapsed(dev->pcm_substream); + +} -- 1.8.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
