Re: [PATCH v6 1/2] ASoC: sunxi: Add Allwinner H6 Digital MIC driver

[班涛]

Hi, Dear:


Maxime Ripard <maxime@xxxxxxxxxx> 于2021年7月15日周四 下午3:47写道：

>
> Hi
>
> On Sun, Jul 11, 2021 at 08:20:55AM -0400, fengzheng923@xxxxxxxxx wrote:
> > From: Ban Tao <fengzheng923@xxxxxxxxx>
> >
> > The Allwinner H6 and later SoCs have an DMIC block
> > which is capable of capture.
> >
> > Signed-off-by: Ban Tao <fengzheng923@xxxxxxxxx>
> >
> > ---
> > v1->v2:
> > 1.Fix some compilation errors.
> > 2.Modify some code styles.
> > ---
> > v2->v3:
> > None.
> > ---
> > v3->v4:
> > 1.add sig_bits.
> > ---
> > v4->v5:
> > None.
> > ---
> > v5->v6:
> > 1.Modify RXFIFO_CTL_MODE to mode 1.
> > ---
> >  MAINTAINERS                   |   7 +
> >  sound/soc/sunxi/Kconfig       |   8 +
> >  sound/soc/sunxi/Makefile      |   1 +
> >  sound/soc/sunxi/sun50i-dmic.c | 403 ++++++++++++++++++++++++++++++++++
> >  4 files changed, 419 insertions(+)
> >  create mode 100644 sound/soc/sunxi/sun50i-dmic.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index e924f9e5df97..8d700baaa3ca 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -760,6 +760,13 @@ L:       linux-media@xxxxxxxxxxxxxxx
> >  S:   Maintained
> >  F:   drivers/staging/media/sunxi/cedrus/
> >
> > +ALLWINNER DMIC DRIVERS
> > +M:   Ban Tao <fengzheng923@xxxxxxxxx>
> > +L:   alsa-devel@xxxxxxxxxxxxxxxx (moderated for non-subscribers)
> > +S:   Maintained
> > +F:   Documentation/devicetree/bindings/sound/allwinner,sun50i-h6-dmic.yaml
> > +F:   sound/soc/sunxi/sun50i-dmic.c
> > +
> >  ALPHA PORT
> >  M:   Richard Henderson <rth@xxxxxxxxxxx>
> >  M:   Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
> > diff --git a/sound/soc/sunxi/Kconfig b/sound/soc/sunxi/Kconfig
> > index ddcaaa98d3cb..2a3bf7722e11 100644
> > --- a/sound/soc/sunxi/Kconfig
> > +++ b/sound/soc/sunxi/Kconfig
> > @@ -56,6 +56,14 @@ config SND_SUN4I_SPDIF
> >         Say Y or M to add support for the S/PDIF audio block in the Allwinner
> >         A10 and affiliated SoCs.
> >
> > +config SND_SUN50I_DMIC
> > +     tristate "Allwinner H6 DMIC Support"
> > +     depends on (OF && ARCH_SUNXI) || COMPILE_TEST
> > +     select SND_SOC_GENERIC_DMAENGINE_PCM
> > +     help
> > +       Say Y or M to add support for the DMIC audio block in the Allwinner
> > +       H6 and affiliated SoCs.
> > +
> >  config SND_SUN8I_ADDA_PR_REGMAP
> >       tristate
> >       select REGMAP
> > diff --git a/sound/soc/sunxi/Makefile b/sound/soc/sunxi/Makefile
> > index a86be340a076..4483fe9c94ef 100644
> > --- a/sound/soc/sunxi/Makefile
> > +++ b/sound/soc/sunxi/Makefile
> > @@ -6,3 +6,4 @@ obj-$(CONFIG_SND_SUN8I_CODEC_ANALOG) += sun8i-codec-analog.o
> >  obj-$(CONFIG_SND_SUN50I_CODEC_ANALOG) += sun50i-codec-analog.o
> >  obj-$(CONFIG_SND_SUN8I_CODEC) += sun8i-codec.o
> >  obj-$(CONFIG_SND_SUN8I_ADDA_PR_REGMAP) += sun8i-adda-pr-regmap.o
> > +obj-$(CONFIG_SND_SUN50I_DMIC) += sun50i-dmic.o
> > diff --git a/sound/soc/sunxi/sun50i-dmic.c b/sound/soc/sunxi/sun50i-dmic.c
> > new file mode 100644
> > index 000000000000..bbac836ba4de
> > --- /dev/null
> > +++ b/sound/soc/sunxi/sun50i-dmic.c
> > @@ -0,0 +1,403 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +//
> > +// This driver supports the DMIC in Allwinner's H6 SoCs.
> > +//
> > +// Copyright 2021 Ban Tao <fengzheng923@xxxxxxxxx>
> > +
> > +#include <linux/clk.h>
> > +#include <linux/device.h>
> > +#include <linux/of_device.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/reset.h>
> > +#include <sound/dmaengine_pcm.h>
> > +#include <sound/pcm_params.h>
> > +#include <sound/soc.h>
> > +
> > +#define SUN50I_DMIC_EN_CTL           (0x00)
> > +     #define SUN50I_DMIC_EN_CTL_GLOBE                        BIT(8)
> > +     #define SUN50I_DMIC_EN_CTL_CHAN(v)              ((v) << 0)
> > +     #define SUN50I_DMIC_EN_CTL_CHAN_MASK            GENMASK(7, 0)
> > +#define SUN50I_DMIC_SR                       (0x04)
> > +     #define SUN50I_DMIC_SR_SAMPLE_RATE(v)           ((v) << 0)
> > +     #define SUN50I_DMIC_SR_SAMPLE_RATE_MASK         GENMASK(2, 0)
> > +#define SUN50I_DMIC_CTL                      (0x08)
> > +     #define SUN50I_DMIC_CTL_OVERSAMPLE_RATE         BIT(0)
> > +#define SUN50I_DMIC_DATA                     (0x10)
> > +#define SUN50I_DMIC_INTC                     (0x14)
> > +     #define SUN50I_DMIC_FIFO_DRQ_EN                 BIT(2)
> > +#define SUN50I_DMIC_INT_STA          (0x18)
> > +     #define SUN50I_DMIC_INT_STA_OVERRUN_IRQ_PENDING BIT(1)
> > +     #define SUN50I_DMIC_INT_STA_DATA_IRQ_PENDING    BIT(0)
> > +#define SUN50I_DMIC_RXFIFO_CTL               (0x1c)
> > +     #define SUN50I_DMIC_RXFIFO_CTL_FLUSH            BIT(31)
> > +     #define SUN50I_DMIC_RXFIFO_CTL_MODE             BIT(9)
> > +     #define SUN50I_DMIC_RXFIFO_CTL_RESOLUTION       BIT(8)
> > +#define SUN50I_DMIC_CH_NUM           (0x24)
> > +     #define SUN50I_DMIC_CH_NUM_N(v)                 ((v) << 0)
> > +     #define SUN50I_DMIC_CH_NUM_N_MASK               GENMASK(2, 0)
> > +#define SUN50I_DMIC_CNT                      (0x2c)
> > +     #define SUN50I_DMIC_CNT_N                       BIT(0)
> > +#define SUN50I_DMIC_HPF_CTRL         (0x38)
> > +#define SUN50I_DMIC_VERSION          (0x50)
> > +
> > +
>
> There's multiple blank lines here
>
> > +struct sun50i_dmic_dev {
> > +     struct clk *dmic_clk;
> > +     struct clk *bus_clk;
> > +     struct reset_control *rst;
> > +     struct regmap *regmap;
> > +     struct snd_dmaengine_dai_dma_data dma_params_rx;
> > +     unsigned int chan_en;
> > +};
> > +
> > +struct dmic_rate {
> > +     unsigned int samplerate;
> > +     unsigned int rate_bit;
> > +};
> > +
> > +static int sun50i_dmic_startup(struct snd_pcm_substream *substream,
> > +                            struct snd_soc_dai *cpu_dai)
> > +{
> > +     struct snd_soc_pcm_runtime *rtd = substream->private_data;
> > +     struct sun50i_dmic_dev *host = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
> > +
> > +     /* only support capture */
> > +     if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
> > +             return -EINVAL;
> > +
> > +     regmap_update_bits(host->regmap, SUN50I_DMIC_RXFIFO_CTL,
> > +                        SUN50I_DMIC_RXFIFO_CTL_FLUSH,
> > +                        SUN50I_DMIC_RXFIFO_CTL_FLUSH);
> > +     regmap_write(host->regmap, SUN50I_DMIC_CNT, SUN50I_DMIC_CNT_N);
> > +
> > +     return 0;
> > +}
> > +
> > +static int sun50i_dmic_hw_params(struct snd_pcm_substream *substream,
> > +                              struct snd_pcm_hw_params *params,
> > +                              struct snd_soc_dai *cpu_dai)
> > +{
> > +     int i = 0;
> > +     unsigned long rate = params_rate(params);
> > +     unsigned int mclk = 0;
> > +     unsigned int channels = params_channels(params);
> > +     struct sun50i_dmic_dev *host = snd_soc_dai_get_drvdata(cpu_dai);
> > +     static struct dmic_rate dmic_rate_s[] = {
> > +             {44100, 0x0},
> > +             {48000, 0x0},
> > +             {22050, 0x2},
> > +             {24000, 0x2},
> > +             {11025, 0x4},
> > +             {12000, 0x4},
> > +             {32000, 0x1},
> > +             {16000, 0x3},
> > +             {8000,  0x5},
> > +     };
>
> We should order these items. It looks like descending rate makes the
> most sense?
>
> Also, I'm not sure why we need to make that array local, can't this be a
> global variable?
>
> > +     /* DMIC num is N+1 */
> > +     regmap_update_bits(host->regmap, SUN50I_DMIC_CH_NUM,
> > +                        SUN50I_DMIC_CH_NUM_N_MASK,
> > +                        SUN50I_DMIC_CH_NUM_N(channels - 1));
> > +     host->chan_en = (1 << channels) - 1;
> > +     regmap_write(host->regmap, SUN50I_DMIC_HPF_CTRL, host->chan_en);
>
> Do we need to store the channels bitmask in the main structure? It looks
> fairly easy to generate, so I guess we could just use a macro

I need to store channels bitmask and use it in sun50i_dmic_trigger function.

>
> > +     switch (params_format(params)) {
> > +     case SNDRV_PCM_FORMAT_S16_LE:
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_RXFIFO_CTL,
> > +                                SUN50I_DMIC_RXFIFO_CTL_RESOLUTION, 0);
> > +             break;
> > +     case SNDRV_PCM_FORMAT_S24_LE:
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_RXFIFO_CTL,
> > +                                SUN50I_DMIC_RXFIFO_CTL_RESOLUTION,
> > +                                SUN50I_DMIC_RXFIFO_CTL_RESOLUTION);
> > +             break;
>
> These two defines could be named a bit better, it's not really clear
> what SUN50I_DMIC_RXFIFO_CTL_RESOLUTION means, exactly, as opposed to 0
> (while it's actually the sample width).
>
> What about something like SUN50I_DMIC_RXFIFO_CTL_SAMPLE_16 (for 0) and
> _24 (for 1), while changing SUN50I_DMIC_RXFIFO_CTL_RESOLUTION for
> SUN50I_DMIC_RXFIFO_CTL_SAMPLE_MASK ?
>
> > +     default:
> > +             dev_err(cpu_dai->dev, "Invalid format!\n");
> > +             return -EINVAL;
> > +     }
> > +     regmap_update_bits(host->regmap, SUN50I_DMIC_RXFIFO_CTL,
> > +                        SUN50I_DMIC_RXFIFO_CTL_MODE,
> > +                        SUN50I_DMIC_RXFIFO_CTL_MODE);
>
> Same thing here, MODE doesn't really explain what this does, and why
> we'd want to always set it.
>
> I guess 0 is LSB_ZERO and 1 is MSB_SIGN?

Yes.

>
> > +     switch (rate) {
> > +     case 11025:
> > +     case 22050:
> > +     case 44100:
> > +             mclk = 22579200;
> > +             break;
> > +     case 8000:
> > +     case 12000:
> > +     case 16000:
> > +     case 24000:
> > +     case 32000:
> > +     case 48000:
> > +             mclk = 24576000;
> > +             break;
> > +     default:
> > +             dev_err(cpu_dai->dev, "Invalid rate!\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     if (clk_set_rate(host->dmic_clk, mclk)) {
> > +             dev_err(cpu_dai->dev, "mclk : %u not support\n", mclk);
> > +             return -EINVAL;
> > +     }
> > +
> > +     for (i = 0; i < ARRAY_SIZE(dmic_rate_s); i++) {
> > +             if (dmic_rate_s[i].samplerate == rate) {
> > +                     regmap_update_bits(host->regmap, SUN50I_DMIC_SR,
> > +                                        SUN50I_DMIC_SR_SAMPLE_RATE_MASK,
> > +                                        SUN50I_DMIC_SR_SAMPLE_RATE(dmic_rate_s[i].rate_bit));
> > +                     break;
> > +             }
> > +     }
> > +
> > +     switch (params_physical_width(params)) {
> > +     case 16:
> > +             host->dma_params_rx.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
> > +             break;
> > +     case 32:
> > +             host->dma_params_rx.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> > +             break;
> > +     default:
> > +             dev_err(cpu_dai->dev, "Unsupported physical sample width: %d\n",
> > +                     params_physical_width(params));
> > +             return -EINVAL;
> > +     }
> > +
> > +     /* oversamplerate adjust */
> > +     if (params_rate(params) >= 24000)
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_CTL,
> > +                                SUN50I_DMIC_CTL_OVERSAMPLE_RATE,
> > +                                SUN50I_DMIC_CTL_OVERSAMPLE_RATE);
> > +     else
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_CTL,
> > +                                SUN50I_DMIC_CTL_OVERSAMPLE_RATE, 0);
> > +
> > +     return 0;
> > +}
> > +
> > +static int sun50i_dmic_trigger(struct snd_pcm_substream *substream, int cmd,
> > +                            struct snd_soc_dai *dai)
> > +{
> > +     int ret = 0;
> > +     struct sun50i_dmic_dev *host = snd_soc_dai_get_drvdata(dai);
> > +
> > +     if (substream->stream != SNDRV_PCM_STREAM_CAPTURE)
> > +             return -EINVAL;
> > +
> > +     switch (cmd) {
> > +     case SNDRV_PCM_TRIGGER_START:
> > +     case SNDRV_PCM_TRIGGER_RESUME:
> > +     case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> > +             /* DRQ ENABLE */
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_INTC,
> > +                                SUN50I_DMIC_FIFO_DRQ_EN,
> > +                                SUN50I_DMIC_FIFO_DRQ_EN);
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_EN_CTL,
> > +                                SUN50I_DMIC_EN_CTL_CHAN_MASK,
> > +                                SUN50I_DMIC_EN_CTL_CHAN(host->chan_en));
> > +             /* Global enable */
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_EN_CTL,
> > +                                SUN50I_DMIC_EN_CTL_GLOBE,
> > +                                SUN50I_DMIC_EN_CTL_GLOBE);
> > +             break;
>
> Do we really need to clear the channel and global enable bits? and DRQ?

Why not? I think we should clear them when not in use......

>
> > +     case SNDRV_PCM_TRIGGER_STOP:
> > +     case SNDRV_PCM_TRIGGER_SUSPEND:
> > +     case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> > +             /* DRQ DISABLE */
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_INTC,
> > +                                SUN50I_DMIC_FIFO_DRQ_EN, 0);
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_EN_CTL,
> > +                                SUN50I_DMIC_EN_CTL_CHAN_MASK,
> > +                                SUN50I_DMIC_EN_CTL_CHAN(0));
> > +             /* Global disable */
> > +             regmap_update_bits(host->regmap, SUN50I_DMIC_EN_CTL,
> > +                                SUN50I_DMIC_EN_CTL_GLOBE, 0);
> > +             break;
> > +
> > +     default:
> > +             ret = -EINVAL;
> > +             break;
> > +     }
> > +     return ret;
> > +}
> > +
> > +static int sun50i_dmic_soc_dai_probe(struct snd_soc_dai *dai)
> > +{
> > +     struct sun50i_dmic_dev *host = snd_soc_dai_get_drvdata(dai);
> > +
> > +     snd_soc_dai_init_dma_data(dai, NULL, &host->dma_params_rx);
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct snd_soc_dai_ops sun50i_dmic_dai_ops = {
> > +     .startup        = sun50i_dmic_startup,
> > +     .trigger        = sun50i_dmic_trigger,
> > +     .hw_params      = sun50i_dmic_hw_params,
> > +};
> > +
> > +static const struct regmap_config sun50i_dmic_regmap_config = {
> > +     .reg_bits = 32,
> > +     .reg_stride = 4,
> > +     .val_bits = 32,
> > +     .max_register = SUN50I_DMIC_VERSION,
> > +     .cache_type = REGCACHE_NONE,
> > +};
> > +
> > +#define      SUN50I_DMIC_RATES (SNDRV_PCM_RATE_8000_48000)
> > +#define SUN50I_FORMATS       (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)
>
> SUN50I_DMIC_RATES has a tab between the define and its name, while
> SUN50I_FORMATS has the tab after the name. We should be consistent.
> Similarly, we should name both with the SUN50I_DMIC prefix.
>
> > +static struct snd_soc_dai_driver sun50i_dmic_dai = {
> > +     .capture = {
> > +             .channels_min = 1,
> > +             .channels_max = 8,
> > +             .rates = SUN50I_DMIC_RATES,
> > +             .formats = SUN50I_FORMATS,
> > +             .sig_bits = 21,
> > +     },
> > +     .probe = sun50i_dmic_soc_dai_probe,
> > +     .ops = &sun50i_dmic_dai_ops,
> > +     .name = "dmic",
> > +};
> > +
> > +static const struct of_device_id sun50i_dmic_of_match[] = {
> > +     {
> > +             .compatible = "allwinner,sun50i-h6-dmic",
> > +     },
> > +     { /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, sun50i_dmic_of_match);
> > +
> > +static const struct snd_soc_component_driver sun50i_dmic_component = {
> > +     .name           = "sun50i-dmic",
> > +};
> > +
> > +static int sun50i_dmic_runtime_suspend(struct device *dev)
> > +{
> > +     struct sun50i_dmic_dev *host  = dev_get_drvdata(dev);
> > +
> > +     clk_disable_unprepare(host->dmic_clk);
> > +     clk_disable_unprepare(host->bus_clk);
> > +
> > +     return 0;
> > +}
> > +
> > +static int sun50i_dmic_runtime_resume(struct device *dev)
> > +{
> > +     struct sun50i_dmic_dev *host  = dev_get_drvdata(dev);
> > +     int ret;
> > +
> > +     ret = clk_prepare_enable(host->dmic_clk);
> > +     if (ret)
> > +             return ret;
>
> A new line here would be great.
>
> > +     ret = clk_prepare_enable(host->bus_clk);
> > +     if (ret)
> > +             clk_disable_unprepare(host->dmic_clk);
> > +
> > +     return ret;
>
> In general we prefer to treat the error path and the success path
> differently. In this case it would mean changing that part to
>
> ret = clk_prepare_enable(host->bus_clk);
> if (ret) {
>          clk_disable_unprepare(host->dmic_clk);
>          return ret;
> }
>
> return 0;
>
> > +}
> > +
> > +static int sun50i_dmic_probe(struct platform_device *pdev)
> > +{
> > +     struct sun50i_dmic_dev *host;
> > +     struct resource *res;
> > +     int ret;
> > +     void __iomem *base;
> > +
> > +     host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
> > +     if (!host)
> > +             return -ENOMEM;
> > +
> > +     /* Get the addresses */
> > +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     base = devm_ioremap_resource(&pdev->dev, res);
> > +     if (IS_ERR(base))
> > +             return dev_err_probe(&pdev->dev, PTR_ERR(base),
> > +                                  "get resource failed.\n");
> > +
> > +     host->regmap = devm_regmap_init_mmio(&pdev->dev, base,
> > +                                             &sun50i_dmic_regmap_config);
>
> Your second line should be aligned on the opening parenthesis
>
> > +     /* Clocks */
> > +     host->bus_clk = devm_clk_get(&pdev->dev, "bus");
> > +     if (IS_ERR(host->bus_clk))
> > +             return dev_err_probe(&pdev->dev, PTR_ERR(host->bus_clk),
> > +                                  "failed to get bus clock.\n");
> > +
> > +     host->dmic_clk = devm_clk_get(&pdev->dev, "mod");
> > +     if (IS_ERR(host->dmic_clk))
> > +             return dev_err_probe(&pdev->dev, PTR_ERR(host->dmic_clk),
> > +                                  "failed to get dmic clock.\n");
> > +
> > +     host->dma_params_rx.addr = res->start + SUN50I_DMIC_DATA;
> > +     host->dma_params_rx.maxburst = 8;
> > +
> > +     platform_set_drvdata(pdev, host);
> > +
> > +     host->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
> > +     if (IS_ERR(host->rst))
> > +             return dev_err_probe(&pdev->dev, PTR_ERR(host->rst),
> > +                                  "Failed to get reset.\n");
>
> Your binding states that the reset is mandatory so you don't need the
> optional variant.
>
> > +     reset_control_deassert(host->rst);
>
> Can't this be moved to the runtime_pm hooks?

Is this necessary? I see that most of the driver files execute
reset_control_deassert in the probe function, and reset_control_assert
in the remove function.

>
> > +     ret = devm_snd_soc_register_component(&pdev->dev,
> > +                             &sun50i_dmic_component, &sun50i_dmic_dai, 1);
>
> Your second line should be aligned on the opening parenthesis
>
> > +     if (ret)
> > +             return dev_err_probe(&pdev->dev, ret,
> > +                                  "failed to register component.\n");
> > +
> > +     pm_runtime_enable(&pdev->dev);
> > +     if (!pm_runtime_enabled(&pdev->dev)) {
> > +             ret = sun50i_dmic_runtime_resume(&pdev->dev);
> > +             if (ret)
> > +                     goto err_unregister;
> > +     }
>
> We have a depends on PM on some drivers already, so I guess it would
> just make sense to add one more here instead of dealing with whether
> runtime_pm is compiled in or not.

I don't understand. I am referring to the sun4i-spdif.c file. Which
driver files should I refer to?

>
> Also, the name of the label is misleading: it's called err_unregister
> but you don't need to unregister anything and you actually disable
> runtime_pm for that device.
>
> err_disable_runtime_pm or something similar would be a better pick
>
> Thanks!
> Maxime