static int atmel_ac97c_prepare_dma(struct atmel_ac97c *chip, struct snd_pcm_substream *substream, enum dma_data_direction direction) { struct dma_chan *chan; struct dw_cyclic_desc *cdesc; struct snd_pcm_runtime *runtime = substream->runtime; unsigned long buffer_len, period_len; /* * We don't do DMA on "complex" transfers, i.e. with * non-halfword-aligned buffers or lengths. */ if (runtime->dma_addr & 1 || runtime->buffer_size & 1) { dev_dbg(&chip->pdev->dev, "too complex transfer\n"); return -EINVAL; } if (direction == DMA_TO_DEVICE) chan = chip->dma.tx_chan; else chan = chip->dma.rx_chan; buffer_len = frames_to_bytes(runtime, runtime->buffer_size); period_len = frames_to_bytes(runtime, runtime->period_size); cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len, period_len, direction); if (IS_ERR(cdesc)) { dev_dbg(&chip->pdev->dev, "could not prepare cyclic DMA\n"); return PTR_ERR(cdesc); } if (direction == DMA_TO_DEVICE) { cdesc->period_callback = atmel_ac97c_dma_playback_period_done; set_bit(DMA_TX_READY, &chip->flags); } else { cdesc->period_callback = atmel_ac97c_dma_capture_period_done; set_bit(DMA_RX_READY, &chip->flags); } cdesc->period_callback_param = chip; return 0; }
static int atmel_abdac_prepare_dma(struct atmel_abdac *dac, struct snd_pcm_substream *substream, enum dma_data_direction direction) { struct dma_chan *chan = dac->dma.chan; struct dw_cyclic_desc *cdesc; struct snd_pcm_runtime *runtime = substream->runtime; unsigned long buffer_len, period_len; /* * We don't do DMA on "complex" transfers, i.e. with * non-halfword-aligned buffers or lengths. */ if (runtime->dma_addr & 1 || runtime->buffer_size & 1) { dev_dbg(&dac->pdev->dev, "too complex transfer\n"); return -EINVAL; } buffer_len = frames_to_bytes(runtime, runtime->buffer_size); period_len = frames_to_bytes(runtime, runtime->period_size); cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len, period_len, DMA_MEM_TO_DEV); if (IS_ERR(cdesc)) { dev_dbg(&dac->pdev->dev, "could not prepare cyclic DMA\n"); return PTR_ERR(cdesc); } cdesc->period_callback = atmel_abdac_dma_period_done; cdesc->period_callback_param = dac; dac->dma.cdesc = cdesc; set_bit(DMA_READY, &dac->flags); return 0; }