[alsa-devel] [PATCH 4/5] ASoC: dwc: Add devicetree support for Designware I2S

rajeev kumar rajeevkumar.linux at gmail.com
Thu Dec 4 08:43:48 CET 2014


Sorry for the last blank mail.

On Wed, Dec 3, 2014 at 10:09 PM, Andrew Jackson <Andrew.Jackson at arm.com> wrote:
> Convert to driver to use either platform_data or device-tree for configuration
> of the device.  When using device-tree, the I2S block's configuration is read
> from the relevant registers: this reduces the amount of information required in
> the device tree.
>
> Signed-off-by: Andrew Jackson <Andrew.Jackson at arm.com>
> ---
>  .../devicetree/bindings/sound/designware-i2s.txt   |   32 +++
>  sound/soc/dwc/Kconfig                              |    1 +
>  sound/soc/dwc/designware_i2s.c                     |  238 ++++++++++++++++----
>  3 files changed, 222 insertions(+), 49 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/sound/designware-i2s.txt
>
> diff --git a/Documentation/devicetree/bindings/sound/designware-i2s.txt b/Documentation/devicetree/bindings/sound/designware-i2s.txt
> new file mode 100644
> index 0000000..cdee591
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/designware-i2s.txt
> @@ -0,0 +1,32 @@
> +DesignWare I2S controller
> +
> +Required properties:
> + - compatible : Must be "snps,designware-i2s"
> + - reg : Must contain I2S core's registers location and length
> + - clocks : Pairs of phandle and specifier referencing the controller's clocks.
> +   The controller expects two clocks, the clock used for the APB interface and
> +   the clock used as the sampling rate reference clock sample.
> + - clock-names : "apb_plck" for the clock to the APB interface, "i2sclk" for the sample
> +   rate reference clock.
> + - dmas: Pairs of phandle and specifier for the DMA channels that are used by
> +   the core. The core expects one or two dma channels, one for transmit and one for
> +   receive.
> + - dma-names : "tx" for the transmit channel, "rx" for the receive channel.
> +
> +For more details on the 'dma', 'dma-names', 'clock' and 'clock-names' properties
> +please check:
> +       * resource-names.txt
> +       * clock/clock-bindings.txt
> +       * dma/dma.txt
> +
> +Example:
> +
> +       soc_i2s: i2s at 7ff90000 {
> +               compatible = "snps,designware-i2s";
> +               reg = <0x0 0x7ff90000 0x0 0x1000>;
> +               clocks = <&scpi_i2sclk 0>, <&soc_refclk100mhz>;
> +               clock-names = "i2sclk", "apb_pclk";
> +               #sound-dai-cells = <0>;
> +               dmas = <&dma0 5>;
> +               dma-names = "tx";
> +       };
> diff --git a/sound/soc/dwc/Kconfig b/sound/soc/dwc/Kconfig
> index e334900..d50e085 100644
> --- a/sound/soc/dwc/Kconfig
> +++ b/sound/soc/dwc/Kconfig
> @@ -1,6 +1,7 @@
>  config SND_DESIGNWARE_I2S
>         tristate "Synopsys I2S Device Driver"
>         depends on CLKDEV_LOOKUP
> +       select SND_SOC_GENERIC_DMAENGINE_PCM
>         help
>          Say Y or M if you want to add support for I2S driver for
>          Synopsys desigwnware I2S device. The device supports upto
> diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
> index c497ada..083779d 100644
> --- a/sound/soc/dwc/designware_i2s.c
> +++ b/sound/soc/dwc/designware_i2s.c
> @@ -22,6 +22,7 @@
>  #include <sound/pcm.h>
>  #include <sound/pcm_params.h>
>  #include <sound/soc.h>
> +#include <sound/dmaengine_pcm.h>
>
>  /* common register for all channel */
>  #define IER            0x000
> @@ -54,19 +55,46 @@
>  #define I2S_COMP_VERSION       0x01F8
>  #define I2S_COMP_TYPE          0x01FC
>
> +/*
> + * Component parameter register fields - define the I2S block's
> + * configuration.
> + */
> +#define        COMP1_TX_WORDSIZE_3(r)  (((r) & GENMASK(27, 25)) >> 25)
> +#define        COMP1_TX_WORDSIZE_2(r)  (((r) & GENMASK(24, 22)) >> 22)
> +#define        COMP1_TX_WORDSIZE_1(r)  (((r) & GENMASK(21, 19)) >> 19)
> +#define        COMP1_TX_WORDSIZE_0(r)  (((r) & GENMASK(18, 16)) >> 16)
> +#define        COMP1_TX_CHANNELS(r)    (((r) & GENMASK(10, 9)) >> 9)
> +#define        COMP1_RX_CHANNELS(r)    (((r) & GENMASK(8, 7)) >> 7)
> +#define        COMP1_RX_ENABLED(r)     (((r) & BIT(6)) >> 6)
> +#define        COMP1_TX_ENABLED(r)     (((r) & BIT(5)) >> 5)
> +#define        COMP1_MODE_EN(r)        (((r) & BIT(4)) >> 4)
> +#define        COMP1_FIFO_DEPTH_GLOBAL(r)      (((r) & GENMASK(3, 2)) >> 2)
> +#define        COMP1_APB_DATA_WIDTH(r) (((r) & GENMASK(1, 0)) >> 0)
> +
> +#define        COMP2_RX_WORDSIZE_3(r)  (((r) & GENMASK(12, 10)) >> 10)
> +#define        COMP2_RX_WORDSIZE_2(r)  (((r) & GENMASK(9, 7)) >> 7)
> +#define        COMP2_RX_WORDSIZE_1(r)  (((r) & GENMASK(5, 3)) >> 3)
> +#define        COMP2_RX_WORDSIZE_0(r)  (((r) & GENMASK(2, 0)) >> 0)
> +
>  #define MAX_CHANNEL_NUM                8
>  #define MIN_CHANNEL_NUM                2
>
> +union snd_dma_data {
> +       struct i2s_dma_data pd;
> +       struct snd_dmaengine_dai_dma_data dt;
> +};
> +
>  struct dw_i2s_dev {
>         void __iomem *i2s_base;
>         struct clk *clk;
>         int active;
>         unsigned int capability;
>         struct device *dev;
> +       bool using_pd;
>
>         /* data related to DMA transfers b/w i2s and DMAC */
> -       struct i2s_dma_data play_dma_data;
> -       struct i2s_dma_data capture_dma_data;
> +       union snd_dma_data play_dma_data;
> +       union snd_dma_data capture_dma_data;
>         struct i2s_clk_config_data config;
>         int (*i2s_clk_cfg)(struct i2s_clk_config_data *config);
>  };
> @@ -153,7 +181,7 @@ static int dw_i2s_startup(struct snd_pcm_substream *substream,
>                 struct snd_soc_dai *cpu_dai)
>  {
>         struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);
> -       struct i2s_dma_data *dma_data = NULL;
> +       union snd_dma_data *dma_data = NULL;
>
>         if (!(dev->capability & DWC_I2S_RECORD) &&
>                         (substream->stream == SNDRV_PCM_STREAM_CAPTURE))
> @@ -227,8 +255,7 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
>
>         i2s_disable_channels(dev, substream->stream);
>
> -       /* Iterate over set of channels - independently controlled.
> -        */
> +       /* Iterate over set of channels - independently controlled. */

I dont think so this iteration is required as there are independent
channels available.

I don't have the h/w to test this patch. Can anyone test this ?

>         do {
>                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
>                         i2s_write_reg(dev->i2s_base, TCR(ch_reg),
> @@ -251,13 +278,18 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
>
>         config->sample_rate = params_rate(params);
>
> -       if (!dev->i2s_clk_cfg)
> -               return -EINVAL;
> +       if (dev->using_pd) {
> +               ret = dev->i2s_clk_cfg(config);
> +               if (ret < 0) {
> +                       dev_err(dev->dev, "runtime audio clk config fail\n");
> +                       return ret;
> +               }
> +       } else {
> +               u32     bitclk;
>
> -       ret = dev->i2s_clk_cfg(config);
> -       if (ret < 0) {
> -               dev_err(dev->dev, "runtime audio clk config fail\n");
> -               return ret;
> +               /* TODO: Validate sample rate against permissible set */
> +               bitclk = config->sample_rate * config->data_width * 2;
> +               clk_set_rate(dev->clk, bitclk);
>         }
>
>         return 0;
> @@ -331,6 +363,31 @@ static int dw_i2s_resume(struct snd_soc_dai *dai)
>  #define dw_i2s_resume  NULL
>  #endif
>
> +/* Maximum resolution of a channel - not uniformly spaced */
> +static const u32 fifo_width[] = {
> +       12, 16, 20, 24, 32, 0, 0, 0
> +};
> +
> +/* Width of (DMA) bus */
> +static const u32 bus_widths[] = {
> +       DMA_SLAVE_BUSWIDTH_1_BYTE,
> +       DMA_SLAVE_BUSWIDTH_2_BYTES,
> +       DMA_SLAVE_BUSWIDTH_4_BYTES,
> +       DMA_SLAVE_BUSWIDTH_UNDEFINED
> +};
> +
> +/* PCM format to support channel resolution */
> +static const u32 formats[] = {
> +       SNDRV_PCM_FMTBIT_S16_LE,
> +       SNDRV_PCM_FMTBIT_S16_LE,
> +       SNDRV_PCM_FMTBIT_S24_LE,
> +       SNDRV_PCM_FMTBIT_S24_LE,
> +       SNDRV_PCM_FMTBIT_S32_LE,
> +       0,
> +       0,
> +       0
> +};
> +
>  static int dw_i2s_probe(struct platform_device *pdev)
>  {
>         const struct i2s_platform_data *pdata = pdev->dev.platform_data;
> @@ -340,11 +397,6 @@ static int dw_i2s_probe(struct platform_device *pdev)
>         unsigned int cap;
>         struct snd_soc_dai_driver *dw_i2s_dai;
>
> -       if (!pdata) {
> -               dev_err(&pdev->dev, "Invalid platform data\n");
> -               return -EINVAL;
> -       }
> -

This check is required..

>         dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
>         if (!dev) {
>                 dev_warn(&pdev->dev, "kzalloc fail\n");
> @@ -373,47 +425,114 @@ static int dw_i2s_probe(struct platform_device *pdev)
>                 return PTR_ERR(dev->i2s_base);
>         }
>
> -       cap = pdata->cap;
> -       dev->capability = cap;
> -       dev->i2s_clk_cfg = pdata->i2s_clk_cfg;
> +       if (pdata) {
> +               dev->using_pd = true;
> +               cap = pdata->cap;
> +               dev->capability = cap;

We should take take capability from DT, as

   if (of_get_property(np, "play", NULL))
        cap |= DWC_I2S_PLAY;
    if (of_get_property(np, "record", NULL))
        cap |= DWC_I2S_RECORD;

> +               dev->i2s_clk_cfg = pdata->i2s_clk_cfg;
> +               if (!dev->i2s_clk_cfg) {
> +                       dev_err(&pdev->dev, "no clock device\n");
> +                       return -ENODEV;
> +               }
>
> -       /* Set DMA slaves info */
> +               /* Set DMA slaves info */
> +
> +               dev->play_dma_data.pd.data = pdata->play_dma_data;

As pdata null check is removed it may create issue here !

> +               dev->capture_dma_data.pd.data = pdata->capture_dma_data;
> +               dev->play_dma_data.pd.addr = res->start + I2S_TXDMA;
> +               dev->capture_dma_data.pd.addr = res->start + I2S_RXDMA;
> +               dev->play_dma_data.pd.max_burst = 16;
> +               dev->capture_dma_data.pd.max_burst = 16;
> +               dev->play_dma_data.pd.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
> +               dev->capture_dma_data.pd.addr_width =
> +                                               DMA_SLAVE_BUSWIDTH_2_BYTES;
> +               dev->play_dma_data.pd.filter = pdata->filter;
> +               dev->capture_dma_data.pd.filter = pdata->filter;
> +
> +               dev->clk = clk_get(&pdev->dev, NULL);
> +               if (IS_ERR(dev->clk))
> +                       return  PTR_ERR(dev->clk);
> +
> +               if (cap & DWC_I2S_PLAY) {
> +                       dev_dbg(&pdev->dev, " designware: play supported\n");
> +                       dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
> +                       dw_i2s_dai->playback.channels_max = pdata->channel;
> +                       dw_i2s_dai->playback.formats = pdata->snd_fmts;
> +                       dw_i2s_dai->playback.rates = pdata->snd_rates;
> +               }
>
> -       dev->play_dma_data.data = pdata->play_dma_data;
> -       dev->capture_dma_data.data = pdata->capture_dma_data;
> -       dev->play_dma_data.addr = res->start + I2S_TXDMA;
> -       dev->capture_dma_data.addr = res->start + I2S_RXDMA;
> -       dev->play_dma_data.max_burst = 16;
> -       dev->capture_dma_data.max_burst = 16;
> -       dev->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
> -       dev->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
> -       dev->play_dma_data.filter = pdata->filter;
> -       dev->capture_dma_data.filter = pdata->filter;
> +               if (cap & DWC_I2S_RECORD) {
> +                       dev_dbg(&pdev->dev, "designware: record supported\n");
> +                       dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
> +                       dw_i2s_dai->capture.channels_max = pdata->channel;
> +                       dw_i2s_dai->capture.formats = pdata->snd_fmts;
> +                       dw_i2s_dai->capture.rates = pdata->snd_rates;
> +               }
> +       } else {
> +               /*
> +                * Read component parameter registers to extract
> +                * the I2S block's configuration.
> +                */
> +               u32 comp1 = i2s_read_reg(dev->i2s_base, I2S_COMP_PARAM_1);
> +               u32 comp2 = i2s_read_reg(dev->i2s_base, I2S_COMP_PARAM_2);
> +               u32 bus_width = bus_widths[COMP1_APB_DATA_WIDTH(comp1)];
> +               u32 fifo_depth = 1 << (1 + COMP1_FIFO_DEPTH_GLOBAL(comp1));
> +               u32 max_size;
> +
> +               dev->using_pd = false;
> +
> +               dev->clk = devm_clk_get(&pdev->dev, "i2sclk");
> +               if (IS_ERR(dev->clk))
> +                       return  PTR_ERR(dev->clk);
> +
> +               /*
> +                * Code presumes all channels are configured with the same
> +                * word size.
> +                */

But why all channels ? You should configure only those channel which
are required. The number of channel you can pass from either pdata or
DT.
This is also not required as before play start you are going to enable
only those channel which are required and disable others.

Best Regards
Rajeev


> +               if (COMP1_TX_ENABLED(comp1)) {
> +                       dev_dbg(&pdev->dev, "playback capable\n");
> +
> +                       dev->capability |= DWC_I2S_PLAY;
> +                       max_size = COMP1_TX_WORDSIZE_0(comp1);
> +                       dev->play_dma_data.dt.addr = res->start + I2S_TXDMA;
> +                       dev->play_dma_data.dt.addr_width = bus_width;
> +                       dev->play_dma_data.dt.chan_name = "TX";
> +                       dev->play_dma_data.dt.fifo_size = fifo_depth *
> +                               (fifo_width[max_size]) >> 8;
> +                       dev->play_dma_data.dt.maxburst = 16;
> +                       dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
> +                       dw_i2s_dai->playback.channels_max =
> +                                       1 << (COMP1_TX_CHANNELS(comp1) + 1);
> +                       dw_i2s_dai->playback.formats = formats[max_size];
> +                       dw_i2s_dai->playback.rates = SNDRV_PCM_RATE_8000_192000;
> +               }
> +               if (COMP1_RX_ENABLED(comp1)) {
> +                       dev_dbg(&pdev->dev, "record capable\n");
> +
> +                       dev->capability |= DWC_I2S_RECORD;
> +                       max_size = COMP2_RX_WORDSIZE_0(comp2);
> +                       dev->capture_dma_data.dt.addr = res->start + I2S_RXDMA;
> +                       dev->capture_dma_data.dt.addr_width = bus_width;
> +                       dev->capture_dma_data.dt.chan_name = "RX";
> +                       dev->capture_dma_data.dt.fifo_size = fifo_depth *
> +                               (fifo_width[max_size] >> 8);
> +                       dev->capture_dma_data.dt.maxburst = 16;
> +                       dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
> +                       dw_i2s_dai->capture.channels_max =
> +                                       1 << (COMP1_RX_CHANNELS(comp1) + 1);
> +                       dw_i2s_dai->capture.formats = formats[max_size];
> +                       dw_i2s_dai->capture.rates = SNDRV_PCM_RATE_8000_192000;
> +               }
> +       }
>
> -       dev->clk = clk_get(&pdev->dev, NULL);
> -       if (IS_ERR(dev->clk))
> -               return  PTR_ERR(dev->clk);
> +       ret = clk_prepare(dev->clk);
> +       if (ret < 0)
> +               goto err_clk_put;
>
>         ret = clk_enable(dev->clk);
>         if (ret < 0)
>                 goto err_clk_put;
>
> -       if (cap & DWC_I2S_PLAY) {
> -               dev_dbg(&pdev->dev, " designware: play supported\n");
> -               dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
> -               dw_i2s_dai->playback.channels_max = pdata->channel;
> -               dw_i2s_dai->playback.formats = pdata->snd_fmts;
> -               dw_i2s_dai->playback.rates = pdata->snd_rates;
> -       }
> -
> -       if (cap & DWC_I2S_RECORD) {
> -               dev_dbg(&pdev->dev, "designware: record supported\n");
> -               dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
> -               dw_i2s_dai->capture.channels_max = pdata->channel;
> -               dw_i2s_dai->capture.formats = pdata->snd_fmts;
> -               dw_i2s_dai->capture.rates = pdata->snd_rates;
> -       }
> -
>         dev->dev = &pdev->dev;
>         dev_set_drvdata(&pdev->dev, dev);
>         ret = snd_soc_register_component(&pdev->dev, &dw_i2s_component,
> @@ -423,6 +542,15 @@ static int dw_i2s_probe(struct platform_device *pdev)
>                 goto err_clk_disable;
>         }
>
> +       if (!dev->using_pd) {
> +               ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
> +               if (ret) {
> +                       dev_err(&pdev->dev,
> +                               "Could not register PCM: %d\n", ret);
> +                       return ret;
> +               }
> +       }
> +
>         return 0;
>
>  err_clk_disable:
> @@ -443,12 +571,24 @@ static int dw_i2s_remove(struct platform_device *pdev)
>         return 0;
>  }
>
> +#ifdef CONFIG_OF
> +static const struct of_device_id dw_i2s_of_match[] = {
> +       { .compatible = "snps,designware-i2s",   },
> +       {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, dw_i2s_of_match);
> +#endif
> +
>  static struct platform_driver dw_i2s_driver = {
>         .probe          = dw_i2s_probe,
>         .remove         = dw_i2s_remove,
>         .driver         = {
>                 .name   = "designware-i2s",
>                 .owner  = THIS_MODULE,
> +#ifdef CONFIG_OF
> +               .of_match_table = dw_i2s_of_match,
> +#endif
>         },
>  };
>
> --
> 1.7.1
>


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