linux-kernel - Re: [PATCH v3 2/2] ASoC: fsl_aud2htx: Add aud2htx module driver

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Date:   Fri, 6 Nov 2020 10:51:03 +0800
From:   Shengjiu Wang <shengjiu.wang@...il.com>
To:     Nicolin Chen <nicoleotsuka@...il.com>
Cc:     Shengjiu Wang <shengjiu.wang@....com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>, alsa-devel@...a-project.org,
        Timur Tabi <timur@...nel.org>, Xiubo Li <Xiubo.Lee@...il.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        linuxppc-dev@...ts.ozlabs.org, Takashi Iwai <tiwai@...e.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Brown <broonie@...nel.org>,
        Fabio Estevam <festevam@...il.com>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 2/2] ASoC: fsl_aud2htx: Add aud2htx module driver

On Thu, Nov 5, 2020 at 9:48 AM Nicolin Chen <nicoleotsuka@...il.com> wrote:
>
> On Mon, Nov 02, 2020 at 09:52:27AM +0800, Shengjiu Wang wrote:
> > The AUD2HTX is a digital module that provides a bridge between
> > the Audio Subsystem and the HDMI RTX Subsystem. This module
> > includes intermediate storage to queue SDMA transactions prior
> > to being synchronized and passed to the HDMI RTX Subsystem over
> > the Audio Link.
> >
> > The AUD2HTX contains a DMA request routed to the SDMA module.
> > This DMA request is controlled based on the watermark level in
> > the 32-entry sample buffer.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@....com>
>
> Acked-by: Nicolin Chen <nicoleotsuka@...il.com>
>
> Despite some small comments inline.
>
> > +static int fsl_aud2htx_dai_probe(struct snd_soc_dai *cpu_dai)
> > +{
> > +     struct fsl_aud2htx *aud2htx = dev_get_drvdata(cpu_dai->dev);
> > +
> > +     /* DMA request when number of entries < WTMK_LOW */
> > +     regmap_update_bits(aud2htx->regmap, AUD2HTX_CTRL_EXT,
> > +                        AUD2HTX_CTRE_DT_MASK, 0);
> > +
> > +     /* Disable interrupts*/
> > +     regmap_update_bits(aud2htx->regmap, AUD2HTX_IRQ_MASK,
> > +                        AUD2HTX_WM_HIGH_IRQ_MASK |
> > +                        AUD2HTX_WM_LOW_IRQ_MASK |
> > +                        AUD2HTX_OVF_MASK,
> > +                        AUD2HTX_WM_HIGH_IRQ_MASK |
> > +                        AUD2HTX_WM_LOW_IRQ_MASK |
> > +                        AUD2HTX_OVF_MASK);
> > +
> > +     /* Configure watermark */
> > +     regmap_update_bits(aud2htx->regmap, AUD2HTX_CTRL_EXT,
> > +                        AUD2HTX_CTRE_WL_MASK,
> > +                        AUD2HTX_WTMK_LOW << AUD2HTX_CTRE_WL_SHIFT);
> > +     regmap_update_bits(aud2htx->regmap, AUD2HTX_CTRL_EXT,
> > +                        AUD2HTX_CTRE_WH_MASK,
> > +                        AUD2HTX_WTMK_HIGH << AUD2HTX_CTRE_WH_SHIFT);
>
> If there isn't a hard requirement from hardware, feels better to
> combine all the writes to AUD2HTX_CTRL_EXT into one single MMIO.

ok, will update it.

>
> > +static irqreturn_t fsl_aud2htx_isr(int irq, void *dev_id)
> > +{
> > +     return IRQ_HANDLED;
>
> Empty isr? Perhaps can drop the request_irq() at all?

I'd like to keep this for future enhancement, what do you think?

>
> > +static int fsl_aud2htx_probe(struct platform_device *pdev)
> > +{
> > +     struct fsl_aud2htx *aud2htx;
> > +     struct resource *res;
> > +     void __iomem *regs;
> > +     int ret, irq;
> > +
> > +     aud2htx = devm_kzalloc(&pdev->dev, sizeof(*aud2htx), GFP_KERNEL);
> > +     if (!aud2htx)
> > +             return -ENOMEM;
> > +
> > +     aud2htx->pdev = pdev;
> > +
> > +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     regs = devm_ioremap_resource(&pdev->dev, res);
> > +     if (IS_ERR(regs)) {
> > +             dev_err(&pdev->dev, "failed ioremap\n");
> > +             return PTR_ERR(regs);
> > +     }
> > +
> > +     aud2htx->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
> > +                                             &fsl_aud2htx_regmap_config);
> > +     if (IS_ERR(aud2htx->regmap)) {
> > +             dev_err(&pdev->dev, "failed to init regmap");
> > +             return PTR_ERR(aud2htx->regmap);
> > +     }
> > +
> > +     irq = platform_get_irq(pdev, 0);
> > +     if (irq < 0) {
> > +             dev_err(&pdev->dev, "no irq for node %s\n",
> > +                     dev_name(&pdev->dev));
>
> dev_err() already prints dev_name, so not necessary to print again.

ok, will update it

best regards
wang shengjiu