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Message-ID: <6e498021-bf08-3fd8-a3b8-2fcba054f4a0@quicinc.com>
Date:   Sat, 26 Feb 2022 11:28:03 +0530
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Subject: Re: [PATCH v16 6/9] ASoC: qcom: Add support for codec dma driver
Content-Language: en-US
To:     Stephen Boyd <swboyd@chromium.org>, <agross@kernel.org>,
        <alsa-devel@alsa-project.org>, <bgoswami@codeaurora.org>,
        <bjorn.andersson@linaro.org>, <broonie@kernel.org>,
        <devicetree@vger.kernel.org>, <judyhsiao@chromium.org>,
        <lgirdwood@gmail.com>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <perex@perex.cz>,
        <quic_plai@quicinc.com>, <robh+dt@kernel.org>,
        <rohitkr@codeaurora.org>, <srinivas.kandagatla@linaro.org>,
        <tiwai@suse.com>
CC:     Venkata Prasad Potturu <quic_potturu@quicinc.com>
References: <1645716828-15305-1-git-send-email-quic_srivasam@quicinc.com>
 <1645716828-15305-7-git-send-email-quic_srivasam@quicinc.com>
 <CAE-0n53K3Em52tTFK4zmcsf_ZzFbX4uQQ00_uH9=pq44chwyeg@mail.gmail.com>
From:   Srinivasa Rao Mandadapu <quic_srivasam@quicinc.com>
Organization: Qualcomm
In-Reply-To: <CAE-0n53K3Em52tTFK4zmcsf_ZzFbX4uQQ00_uH9=pq44chwyeg@mail.gmail.com>
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On 2/25/2022 5:10 AM, Stephen Boyd wrote:
Thanks for your time Stephen!!!
> Quoting Srinivasa Rao Mandadapu (2022-02-24 07:33:45)
>> diff --git a/sound/soc/qcom/lpass-platform.c b/sound/soc/qcom/lpass-platform.c
>> index 198f27c..b3af971 100644
>> --- a/sound/soc/qcom/lpass-platform.c
>> +++ b/sound/soc/qcom/lpass-platform.c
>> @@ -684,6 +953,17 @@ static irqreturn_t lpass_dma_interrupt_handler(
>>                  reg = LPAIF_IRQCLEAR_REG(v, LPAIF_IRQ_PORT_HOST);
>>                  val = 0;
>>          break;
>> +       case LPASS_CDC_DMA_RX0 ... LPASS_CDC_DMA_RX9:
>> +       case LPASS_CDC_DMA_TX0 ... LPASS_CDC_DMA_TX8:
>> +               map = drvdata->rxtx_lpaif_map;
>> +               reg = LPAIF_RXTX_IRQCLEAR_REG(v, LPAIF_IRQ_PORT_HOST);
>> +               val = 0;
>> +       break;
>> +       case LPASS_CDC_DMA_VA_TX0 ... LPASS_CDC_DMA_VA_TX8:
>> +               map = drvdata->va_lpaif_map;
>> +               reg = LPAIF_VA_IRQCLEAR_REG(v, LPAIF_IRQ_PORT_HOST);
>> +               val = 0;
>> +       break;
> These breaks have the wrong indentation.
Okay. will fix it.
>
>>          default:
>>          dev_err(soc_runtime->dev, "%s: invalid  %d interface\n", __func__, dai_id);
>>          return -EINVAL;
>> @@ -791,16 +1071,115 @@ static irqreturn_t lpass_platform_hdmiif_irq(int irq, void *data)
>>                                  return rv;
>>                  }
>>          }
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static irqreturn_t lpass_platform_rxtxif_irq(int irq, void *data)
>> +{
>> +       struct lpass_data *drvdata = data;
>> +       struct lpass_variant *v = drvdata->variant;
>> +       unsigned int irqs;
>> +       irqreturn_t rv;
>> +       int chan;
>> +
>> +       rv = regmap_read(drvdata->rxtx_lpaif_map,
>> +                       LPAIF_RXTX_IRQSTAT_REG(v, LPAIF_IRQ_PORT_HOST), &irqs);
>> +
>> +       /* Handle per channel interrupts */
>> +       for (chan = 0; chan < LPASS_MAX_CDC_DMA_CHANNELS; chan++) {
>> +               if (irqs & LPAIF_IRQ_ALL(chan) && drvdata->rxtx_substream[chan]) {
>> +                       rv = lpass_dma_interrupt_handler(
>> +                                               drvdata->rxtx_substream[chan],
>> +                                               drvdata, chan, irqs);
>> +                       if (rv != IRQ_HANDLED)
>> +                               return rv;
>> +               }
>> +       }
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static irqreturn_t lpass_platform_vaif_irq(int irq, void *data)
>> +{
>> +       struct lpass_data *drvdata = data;
>> +       struct lpass_variant *v = drvdata->variant;
>> +       unsigned int irqs;
>> +       irqreturn_t rv;
>> +       int chan;
>> +
>> +       rv = regmap_read(drvdata->va_lpaif_map,
>> +                       LPAIF_VA_IRQSTAT_REG(v, LPAIF_IRQ_PORT_HOST), &irqs);
>>
>> +       /* Handle per channel interrupts */
>> +       for (chan = 0; chan < LPASS_MAX_VA_CDC_DMA_CHANNELS; chan++) {
>> +               if (irqs & LPAIF_IRQ_ALL(chan) && drvdata->va_substream[chan]) {
>> +                       rv = lpass_dma_interrupt_handler(
>> +                                               drvdata->va_substream[chan],
>> +                                               drvdata, chan, irqs);
>> +                       if (rv != IRQ_HANDLED)
>> +                               return rv;
>> +               }
>> +       }
>>          return IRQ_HANDLED;
>>   }
>>
>> +static int lpass_platform_prealloc_cdc_dma_buffer(struct snd_soc_component *component,
>> +                                                 struct snd_pcm *pcm, int dai_id)
>> +{
>> +       struct lpass_data *drvdata = snd_soc_component_get_drvdata(component);
>> +       struct snd_pcm_substream *substream;
>> +       struct snd_dma_buffer *buf;
>> +
>> +       if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
>> +               substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
>> +       else
>> +               substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
>> +
>> +       buf = &substream->dma_buffer;
>> +       buf->dev.dev = pcm->card->dev;
>> +       buf->private_data = NULL;
>> +
>> +       /* Assign Codec DMA buffer pointers */
>> +       buf->dev.type = SNDRV_DMA_TYPE_CONTINUOUS;
>> +
>> +       switch (dai_id) {
>> +       case LPASS_CDC_DMA_RX0 ... LPASS_CDC_DMA_RX9:
>> +               buf->bytes = lpass_platform_rxtx_hardware.buffer_bytes_max;
>> +               buf->addr = drvdata->rxtx_cdc_dma_lpm_buf;
>> +               break;
>> +       case LPASS_CDC_DMA_TX0 ... LPASS_CDC_DMA_TX8:
>> +               buf->bytes = lpass_platform_rxtx_hardware.buffer_bytes_max;
>> +               buf->addr = drvdata->rxtx_cdc_dma_lpm_buf + LPASS_RXTX_CDC_DMA_LPM_BUFF_SIZE;
>> +               break;
>> +       case LPASS_CDC_DMA_VA_TX0 ... LPASS_CDC_DMA_VA_TX8:
>> +               buf->bytes = lpass_platform_va_hardware.buffer_bytes_max;
>> +               buf->addr = drvdata->va_cdc_dma_lpm_buf;
>> +               break;
>> +       default:
>> +               break;
>> +       }
>> +
>> +       buf->area = (unsigned char * __force)memremap(buf->addr, buf->bytes, MEMREMAP_WT);
> What's the cast and __force for now? MEMREMAP_WT is almost never used so
Here dma_buffer structure has virtual address(buf->area) of unsigned 
char pointer but memremap returns void pointer.
> this looks wrong. Why can't MEMREMAP_WC be used? But if it's DMA then
Okay. Will update the flag MEMREMAP_WT
> why isn't dma_map_resource() being used?

I am sorry bit confused here. You mean some thing like below.

For Physical address mapping: buf->addr = dma_map_resource(pcm->card->dev, drvdata->va_cdc_dma_lpm_buf,
			     buf->bytes, DMA_BIDIRECTIONAL, 0);
For virtual address mapping. buf->area = (unsigned char * __force)memremap(buf->addr, buf->bytes, MEMREMAP_WC);

>
>> +
>> +       return 0;
>> +}
>> +
>>   static int lpass_platform_pcm_new(struct snd_soc_component *component,
>>                                    struct snd_soc_pcm_runtime *soc_runtime)
>>   {
>>          struct snd_pcm *pcm = soc_runtime->pcm;
>> +       struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(soc_runtime, 0);
>> +       unsigned int dai_id = cpu_dai->driver->id;
>> +
>>          size_t size = lpass_platform_pcm_hardware.buffer_bytes_max;
>>
>> +       /*
>> +        * Lpass codec dma can access only lpass lpm hardware memory.
>> +        * ioremap is for HLOS to access hardware memory.
>> +        */
>> +       if (is_cdc_dma_port(dai_id))
>> +               return lpass_platform_prealloc_cdc_dma_buffer(component, pcm, dai_id);
>> +
>>          return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
>>                                              component->dev, size);
>>   :