Re: [PATCH v8 1/2] ASoC: fsl: Add S/PDIF CPU DAI driver

[Sascha Hauer <s.hauer@pengutronix.de>]

Hi Nicolas,

Some misc other comments inline.

On Mon, Aug 19, 2013 at 08:08:48PM +0800, Nicolin Chen wrote:
> This patch implements a device-tree-only CPU DAI driver for Freescale
> +
> +struct fsl_spdif_priv {
> +	struct spdif_mixer_control fsl_spdif_control;
> +	struct snd_soc_dai_driver cpu_dai_drv;
> +	struct platform_device *pdev;
> +	struct regmap *regmap;
> +	atomic_t dpll_locked;

You don't need an atomic_t to track a bool variable. Use a plain bool or
int instead.

> +	u8 txclk_div[SPDIF_TXRATE_MAX];
> +	u8 txclk_src[SPDIF_TXRATE_MAX];
> +	u8 rxclk_src;
> +	struct clk *txclk[SPDIF_TXRATE_MAX];
> +	struct clk *rxclk;
> +	struct snd_dmaengine_dai_dma_data dma_params_tx;
> +	struct snd_dmaengine_dai_dma_data dma_params_rx;
> +
> +	/* The name space will be allocated dynamically */
> +	char name[0];
> +};
> +
> +
> +#ifdef DEBUG
> +static void dumpregs(struct fsl_spdif_priv *spdif_priv)
> +{
> +	struct regmap *regmap = spdif_priv->regmap;
> +	struct platform_device *pdev = spdif_priv->pdev;
> +	u32 val, i;
> +	int ret;
> +
> +	/* Valid address set of SPDIF is {[0x0-0x38], 0x44, 0x50} */
> +	for (i = 0 ; i <= REG_SPDIF_STC; i += 4) {
> +		ret = regmap_read(regmap, REG_SPDIF_SCR + i, &val);
> +		if (!ret)
> +			dev_dbg(&pdev->dev, "REG 0x%02x = 0x%06x\n", i, val);
> +	}
> +}
> +#else
> +static void dumpregs(struct fsl_spdif_priv *spdif_priv) {}
> +#endif

Is this needed? regmap provides a register dump in debugfs.

> +
> +static int spdif_clk_set_rate(struct clk *clk, unsigned long rate)
> +{
> +	unsigned long rate_actual;
> +
> +	rate_actual = clk_round_rate(clk, rate);
> +	return clk_set_rate(clk, rate_actual);
> +}

clk_round_rate returns the rate which clk_set_rate would set if called
with the same rate. The clk_round_rate() is unnecessary.

> +
> +	dev_dbg(&pdev->dev, "expected clock rate = %d\n",
> +			(int)(64 * sample_rate * div));
> +	dev_dbg(&pdev->dev, "acutal clock rate = %d\n",
> +			(int)clk_get_rate(spdif_priv->txclk[rate]));

s/acutal/actual/

Also please use %ld instead of casting the unsigned long to int.

> +
> +	dev_dbg(&pdev->dev, "FreqMeas: %d\n", (int)freqmeas);
> +	dev_dbg(&pdev->dev, "BusclkFreq: %d\n", (int)busclk_freq);
> +	dev_dbg(&pdev->dev, "RxRate: %d\n", (int)tmpval64);

Get rid of the casts

> +
> +	spdif_priv = devm_kzalloc(&pdev->dev,
> +			sizeof(struct fsl_spdif_priv) + strlen(np->name) + 1, GFP_KERNEL);
> +	if (!spdif_priv) {
> +		dev_err(&pdev->dev, "could not allocate DAI object\n");

Please drop this message. You'll never see it.

> +
> +	for (i = 0; i < SPDIF_TXRATE_MAX; i++) {
> +		ret = fsl_spdif_probe_txclk(spdif_priv, i);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	/* Prepare rx/tx clock */
> +	clk_prepare(spdif_priv->rxclk);
> +	for (i = 0; i < SPDIF_TXRATE_MAX; i++)
> +		clk_prepare(spdif_priv->txclk[i]);

Why do you prepare all clocks instead of the one you actually use? Also,
no need to do this here. You can use clk_prepare_enable instead where
you have clk_enable now.

> +
> +/* SPDIF rx clock source */
> +enum spdif_rxclk_src {
> +	SRPC_CLKSRC_0 = 0,
> +	SRPC_CLKSRC_1,
> +	SRPC_CLKSRC_2,
> +	SRPC_CLKSRC_3,
> +	SRPC_CLKSRC_4,
> +	SRPC_CLKSRC_5,
> +	SRPC_CLKSRC_6,
> +	SRPC_CLKSRC_7,
> +	SRPC_CLKSRC_8,
> +	SRPC_CLKSRC_9,
> +	SRPC_CLKSRC_10,
> +	SRPC_CLKSRC_11,
> +	SRPC_CLKSRC_12,
> +	SRPC_CLKSRC_13,
> +	SRPC_CLKSRC_14,
> +	SRPC_CLKSRC_15,
> +};

These are unused and look unnecessary.

> +
> +/* SPDIF tx clksrc */
> +enum spdif_txclk_src {
> +	STC_TXCLK_SRC_0 = 0,
> +	STC_TXCLK_SRC_1,
> +	STC_TXCLK_SRC_2,
> +	STC_TXCLK_SRC_3,
> +	STC_TXCLK_SRC_4,
> +	STC_TXCLK_SRC_5,
> +	STC_TXCLK_SRC_6,
> +	STC_TXCLK_SRC_7,
> +};

Also unused.

Sascha

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