Hi Richard,

On 7/9/2013 22:25, Richard Genoud wrote:
[snip]

+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+
+#include <linux/atmel-ssc.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <asm/mach-types.h>
+#include <mach/hardware.h>
+#include <mach/gpio.h>
+
+#include "../codecs/wm8731.h"
+#include "atmel-pcm.h"
+#include "atmel_ssc_dai.h"

I think some of the header file include is not needed. I keep them as 
simple as following:
---8>---
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>

#include <sound/soc.h>

#include "../codecs/wm8731.h"
#include "atmel_ssc_dai.h"
---<8---

+#define MCLK_RATE 12288000
+
+#define DRV_NAME "sam9x5-snd-wm8731"
+
+/*
+ * Authorized rates are:
+ * Rate = MCLK_RATE / (n * 2)
+ * Where n is in [1..4095]
+ * (cf register SSC_CMR)
+ */
+static unsigned int rates[] = {
+	8000,
+	16000,
+	32000,
+	48000,
+	64000,
+	96000,
+};

This is decided by the codec, while not ssc when ssc in slave mode.

+static struct snd_pcm_hw_constraint_list hw_rates = {
+	.count = ARRAY_SIZE(rates),
+	.list = rates,
+};
+

[snip]

+
+	at91sam9x5ek_dai.dai_fmt = snd_soc_of_parse_daifmt(np, "atmel,");

We can put this into at91sam9x5ek_dai directly, not need to parse it 
then. example as following:
---8>---
.dai_fmt = SND_SOC_DAIFMT_I2S
                 | SND_SOC_DAIFMT_NB_NF
                 | SND_SOC_DAIFMT_CBM_CFM,
---<8---

Best Regards,
Bo Shen