ASoC: core: add TDM slot parsing from DT supports

For some CPU/CODEC DAI devices the TDM slot infomation maybe needed. This
patch adds the slot parsing from DT supports.

TDM slot properties:
    dai-tdm-slot-num : Number of slots in use.
    dai-tdm-slot-width :  Width in bits for each slot.

For instance:
    dai-tdm-slot-num = <2>;
    dai-tdm-slot-width = <8>;

And for each spcified driver, there could be one .of_xlate_tdm_slot_mask()
to specify a explicit mapping of the channels and the slots. If it's absent
the default snd_soc_of_xlate_tdm_slot_mask() will be used to generating the
tx and rx masks.

For snd_soc_of_xlate_tdm_slot_mask(), the tx and rx masks will use a 1 bit
for an active slot as default, and the default active bits are at the LSB of
the masks.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index 71f27c403194..d86e0fc41e80 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -142,6 +142,8 @@ struct snd_soc_dai_ops {
 	 * Called by soc_card drivers, normally in their hw_params.
 	 */
 	int (*set_fmt)(struct snd_soc_dai *dai, unsigned int fmt);
+	int (*of_xlate_tdm_slot_mask)(unsigned int slots,
+		unsigned int *tx_mask, unsigned int *rx_mask);
 	int (*set_tdm_slot)(struct snd_soc_dai *dai,
 		unsigned int tx_mask, unsigned int rx_mask,
 		int slots, int slot_width);