diff options
Diffstat (limited to 'sound/soc/fsl/fsl_ssi.c')
| -rw-r--r-- | sound/soc/fsl/fsl_ssi.c | 79 |
1 files changed, 67 insertions, 12 deletions
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index 4d78df7d7f34..8b075ef5c6b9 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -8,6 +8,26 @@ * This file is licensed under the terms of the GNU General Public License * version 2. This program is licensed "as is" without any warranty of any * kind, whether express or implied. + * + * + * Some notes why imx-pcm-fiq is used instead of DMA on some boards: + * + * The i.MX SSI core has some nasty limitations in AC97 mode. While most + * sane processor vendors have a FIFO per AC97 slot, the i.MX has only + * one FIFO which combines all valid receive slots. We cannot even select + * which slots we want to receive. The WM9712 with which this driver + * was developed with always sends GPIO status data in slot 12 which + * we receive in our (PCM-) data stream. The only chance we have is to + * manually skip this data in the FIQ handler. With sampling rates different + * from 48000Hz not every frame has valid receive data, so the ratio + * between pcm data and GPIO status data changes. Our FIQ handler is not + * able to handle this, hence this driver only works with 48000Hz sampling + * rate. + * Reading and writing AC97 registers is another challenge. The core + * provides us status bits when the read register is updated with *another* + * value. When we read the same register two times (and the register still + * contains the same value) these status bits are not set. We work + * around this by not polling these bits but only wait a fixed delay. */ #include <linux/init.h> @@ -121,11 +141,13 @@ struct fsl_ssi_private { bool new_binding; bool ssi_on_imx; + bool use_dma; struct clk *clk; struct snd_dmaengine_dai_dma_data dma_params_tx; struct snd_dmaengine_dai_dma_data dma_params_rx; struct imx_dma_data filter_data_tx; struct imx_dma_data filter_data_rx; + struct imx_pcm_fiq_params fiq_params; struct { unsigned int rfrc; @@ -355,7 +377,12 @@ static int fsl_ssi_startup(struct snd_pcm_substream *substream, */ /* Enable the interrupts and DMA requests */ - write_ssi(SIER_FLAGS, &ssi->sier); + if (ssi_private->use_dma) + write_ssi(SIER_FLAGS, &ssi->sier); + else + write_ssi(CCSR_SSI_SIER_TIE | CCSR_SSI_SIER_TFE0_EN | + CCSR_SSI_SIER_RIE | + CCSR_SSI_SIER_RFF0_EN, &ssi->sier); /* * Set the watermark for transmit FIFI 0 and receive FIFO 0. We @@ -543,7 +570,7 @@ static int fsl_ssi_dai_probe(struct snd_soc_dai *dai) { struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(dai); - if (ssi_private->ssi_on_imx) { + if (ssi_private->ssi_on_imx && ssi_private->use_dma) { dai->playback_dma_data = &ssi_private->dma_params_tx; dai->capture_dma_data = &ssi_private->dma_params_rx; } @@ -683,6 +710,9 @@ static int fsl_ssi_probe(struct platform_device *pdev) strcpy(ssi_private->name, p); + ssi_private->use_dma = !of_property_read_bool(np, + "fsl,fiq-stream-filter"); + /* Initialize this copy of the CPU DAI driver structure */ memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_dai_template, sizeof(fsl_ssi_dai_template)); @@ -707,12 +737,16 @@ static int fsl_ssi_probe(struct platform_device *pdev) return -ENXIO; } - /* The 'name' should not have any slashes in it. */ - ret = devm_request_irq(&pdev->dev, ssi_private->irq, fsl_ssi_isr, 0, - ssi_private->name, ssi_private); - if (ret < 0) { - dev_err(&pdev->dev, "could not claim irq %u\n", ssi_private->irq); - goto error_irqmap; + if (ssi_private->use_dma) { + /* The 'name' should not have any slashes in it. */ + ret = devm_request_irq(&pdev->dev, ssi_private->irq, + fsl_ssi_isr, 0, ssi_private->name, + ssi_private); + if (ret < 0) { + dev_err(&pdev->dev, "could not claim irq %u\n", + ssi_private->irq); + goto error_irqmap; + } } /* Are the RX and the TX clocks locked? */ @@ -766,7 +800,7 @@ static int fsl_ssi_probe(struct platform_device *pdev) */ ret = of_property_read_u32_array(pdev->dev.of_node, "fsl,ssi-dma-events", dma_events, 2); - if (ret) { + if (ret && !ssi_private->use_dma) { dev_err(&pdev->dev, "could not get dma events\n"); goto error_clk; } @@ -805,9 +839,30 @@ static int fsl_ssi_probe(struct platform_device *pdev) } if (ssi_private->ssi_on_imx) { - ret = imx_pcm_dma_init(pdev); - if (ret) - goto error_dev; + if (!ssi_private->use_dma) { + + /* + * Some boards use an incompatible codec. To get it + * working, we are using imx-fiq-pcm-audio, that + * can handle those codecs. DMA is not possible in this + * situation. + */ + + ssi_private->fiq_params.irq = ssi_private->irq; + ssi_private->fiq_params.base = ssi_private->ssi; + ssi_private->fiq_params.dma_params_rx = + &ssi_private->dma_params_rx; + ssi_private->fiq_params.dma_params_tx = + &ssi_private->dma_params_tx; + + ret = imx_pcm_fiq_init(pdev, &ssi_private->fiq_params); + if (ret) + goto error_dev; + } else { + ret = imx_pcm_dma_init(pdev); + if (ret) + goto error_dev; + } } /* |