ASoC: fsl_sai: Initialize with software reset

This patch adds software reset code in dai_probe() so as to make a true init
by clearing SAI's internal logic, including the bit clock generation, status
flags, and FIFO pointers.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

2 files changed, 8 insertions, 2 deletions

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index faa049797897..7b1eecbc4f60 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -437,8 +437,13 @@ static int fsl_sai_dai_probe(struct snd_soc_dai *cpu_dai)
 {
         struct fsl_sai *sai = dev_get_drvdata(cpu_dai->dev);
 
-        regmap_update_bits(sai->regmap, FSL_SAI_TCSR, 0xffffffff, 0x0);
-        regmap_update_bits(sai->regmap, FSL_SAI_RCSR, 0xffffffff, 0x0);
+        /* Software Reset for both Tx and Rx */
+        regmap_write(sai->regmap, FSL_SAI_TCSR, FSL_SAI_CSR_SR);
+        regmap_write(sai->regmap, FSL_SAI_RCSR, FSL_SAI_CSR_SR);
+        /* Clear SR bit to finish the reset */
+        regmap_write(sai->regmap, FSL_SAI_TCSR, 0);
+        regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
+
         regmap_update_bits(sai->regmap, FSL_SAI_TCR1, FSL_SAI_CR1_RFW_MASK,
                            FSL_SAI_MAXBURST_TX * 2);
         regmap_update_bits(sai->regmap, FSL_SAI_RCR1, FSL_SAI_CR1_RFW_MASK,
diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h
index 0e6c9f595d75..8e1feab7c2a0 100644
--- a/sound/soc/fsl/fsl_sai.h
+++ b/sound/soc/fsl/fsl_sai.h
@@ -48,6 +48,7 @@
 /* SAI Transmit/Recieve Control Register */
 #define FSL_SAI_CSR_TERE        BIT(31)
 #define FSL_SAI_CSR_FR          BIT(25)
+#define FSL_SAI_CSR_SR          BIT(24)
 #define FSL_SAI_CSR_xF_SHIFT    16
 #define FSL_SAI_CSR_xF_W_SHIFT  18
 #define FSL_SAI_CSR_xF_MASK     (0x1f << FSL_SAI_CSR_xF_SHIFT)