Subject: Re: [PATCH v3 2/2] ASoC: fsl_asrc: Add ASRC ASoC CPU DAI and platform drivers

From: Varka Bhadram <[email-masked]>
Date: Fri, 25 Jul 2014 09:54:43 +0530

On 07/25/2014 09:33 AM, Nicolin Chen wrote:
> The Asynchronous Sample Rate Converter (ASRC) converts the sampling rate of a
> signal associated with an input clock into a signal associated with a different
> output clock. The driver currently works as a Front End of DPCM with other Back
> Ends DAI links such as ESAI<->CS42888 and SSI<->WM8962 and SAI. It converts the
> original sample rate to a common rate supported by Back Ends for playback while
> converts the common rate of Back Ends to a desired rate for capture. It has 3
> pairs to support three different substreams within totally 10 channels.
>
(...)

> +Required properties:
> +
> +  - compatible : Compatible list, must contain "fsl,imx35-asrc" or
> +    "fsl,imx53-asrc".
> +
> +  - reg : Offset and length of the register set for the device.
> +
> +  - interrupts : Contains the spdif interrupt.
> +
> +  - dmas : Generic dma devicetree binding as described in
> +	   Documentation/devicetree/bindings/dma/dma.txt.
> +
> +  - dma-names : Six dmas have to be defined: "rxa", "rxb", "rxc", "txa", "txb",
> +		and "txc".
> +
> +  - clocks : Contains an entry for each entry in clock-names.
> +
> +  - clock-names : Includes the following entries:
> +	"mem"		Peripheral access clock to access registers.
> +	"ipg"		Peripheral clock to driver module.
> +	"asrck_<0-f>"	Clock sources for input and output clock.
> +
> +   - big-endian : If this property is absent, the native endian mode will
> +		  be in use as default, or the big endian mode will be in use
> +		  for all the device registers.
> +
> +   - fsl,asrc-rate : Defines a mutual sample rate used by Back End DAI link.
> +
> +   - fsl,asrc-width : Defines a mutual sample width used by Back End DAI link.
> +

indentation for the properties....

- compatible		: Should be "fsl,imx35-asrc" or "fsl,imx53-asrc".
- reg			: Offset and length of the register set for the device.
....

(...)

> +
> +static const struct platform_device_id fsl_asrc_devtype[] = {
> +	{
> +		.name = "imx35-asrc",
> +		.driver_data = IMX35_ASRC,
> +	}, {
> +		.name = "imx53-asrc",
> +		.driver_data = IMX53_ASRC,
> +	}, {
> +		/* sentinel */
> +	}
> +};
> +MODULE_DEVICE_TABLE(platform, fsl_asrc_devtype);
> +
> +static const struct of_device_id fsl_asrc_ids[] = {
> +	{
> +		.compatible = "fsl,imx35-asrc",
> +		.data = &fsl_asrc_devtype[IMX35_ASRC],
> +	}, {
> +		.compatible = "fsl,imx53-asrc",
> +		.data = &fsl_asrc_devtype[IMX53_ASRC],
> +	}, {
> +		/* sentinel */
> +	}
> +};
> +MODULE_DEVICE_TABLE(of, fsl_asrc_ids);
> +

move these ids after probe/remove... every driver follows same thing...

> +static irqreturn_t fsl_asrc_isr(int irq, void *dev_id)
> +{
> +	struct fsl_asrc *asrc_priv = (struct fsl_asrc *)dev_id;
> +	struct device *dev = &asrc_priv->pdev->dev;
> +	enum asrc_pair_index index;
> +	u32 status;
> +
> +	regmap_read(asrc_priv->regmap, REG_ASRSTR, &status);
> +
> +	/* Clean overload error */
> +	regmap_write(asrc_priv->regmap, REG_ASRSTR, ASRSTR_AOLE);
> +
> +	/*
> +	 * We here use dev_dbg() for all exceptions because ASRC itself does
> +	 * not care if FIFO overflowed or underrun while a warning in the
> +	 * interrupt would result a ridged conversion.
> +	 */
> +	for (index = ASRC_PAIR_A; index < ASRC_PAIR_MAX_NUM; index++) {
> +		if (!asrc_priv->pair[index])
> +			continue;
> +
> +		if (status & ASRSTR_ATQOL) {
> +			asrc_priv->pair[index]->error |= ASRC_TASK_Q_OVERLOAD;
> +			dev_dbg(dev, "ASRC Task Queue FIFO overload");

missed terminating new line (\n)...

> +		}
> +
> +		if (status & ASRSTR_AOOL(index)) {
> +			asrc_priv->pair[index]->error |= ASRC_OUTPUT_TASK_OVERLOAD;
> +			pair_dbg("Output Task Overload");

same

> +		}
> +
> +		if (status & ASRSTR_AIOL(index)) {
> +			asrc_priv->pair[index]->error |= ASRC_INPUT_TASK_OVERLOAD;
> +			pair_dbg("Input Task Overload");

same

> +		}
> +
> +		if (status & ASRSTR_AODO(index)) {
> +			asrc_priv->pair[index]->error |= ASRC_OUTPUT_BUFFER_OVERFLOW;
> +			pair_dbg("Output Data Buffer has overflowed");

same

> +		}
> +
> +		if (status & ASRSTR_AIDU(index)) {
> +			asrc_priv->pair[index]->error |= ASRC_INPUT_BUFFER_UNDERRUN;
> +			pair_dbg("Input Data Buffer has underflowed");

same..

> +		}
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +

(...)

> +/**
> + * Configure input and output thresholds
> + */
> +static int fsl_asrc_set_watermarks(struct fsl_asrc_pair *pair, u32 in, u32 out)
> +{

static void for function..?

> +	struct fsl_asrc *asrc_priv = pair->asrc_priv;
> +	enum asrc_pair_index index = pair->index;
> +
> +	regmap_update_bits(asrc_priv->regmap, REG_ASRMCR(index),
> +			   ASRMCRi_EXTTHRSHi_MASK |
> +			   ASRMCRi_INFIFO_THRESHOLD_MASK |
> +			   ASRMCRi_OUTFIFO_THRESHOLD_MASK,
> +			   ASRMCRi_EXTTHRSHi |
> +			   ASRMCRi_INFIFO_THRESHOLD(in) |
> +			   ASRMCRi_OUTFIFO_THRESHOLD(out));
> +
> +	return 0;
> +}

(...)

> +static const struct dev_pm_ops fsl_asrc_pm = {
> +	SET_RUNTIME_PM_OPS(fsl_asrc_runtime_suspend, fsl_asrc_runtime_resume, NULL)
> +	SET_SYSTEM_SLEEP_PM_OPS(fsl_asrc_suspend, fsl_asrc_resume)
> +};
> +

move device ids to here...

> +static struct platform_driver fsl_asrc_driver = {
> +	.probe = fsl_asrc_probe,
> +	.driver = {
> +		.name = "fsl-asrc",
> +		.of_match_table = fsl_asrc_ids,
> +		.pm = &fsl_asrc_pm,
> +	},
> +};
> +module_platform_driver(fsl_asrc_driver);

Thanks...

-- 
Regards,
Varka Bhadram.