ASoC: SOF: Intel: export hda_sdw_bpt_get_buf_size_aligment

The dma buffer need to be a multiple of data block size and
the fifo size. Export a function to return the LCM of data
block size and the fifo size.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>

Author: bardliao

include/sound/hda-sdw-bpt.h

@@ -30,6 +30,8 @@ int hda_sdw_bpt_wait(struct device *dev, struct hdac_ext_stream *bpt_tx_stream,
 int hda_sdw_bpt_close(struct device *dev, struct hdac_ext_stream *bpt_tx_stream,
 		      struct snd_dma_buffer *dmab_tx_bdl, struct hdac_ext_stream *bpt_rx_stream,
 		      struct snd_dma_buffer *dmab_rx_bdl);
+
+unsigned int hda_sdw_bpt_get_buf_size_alignment(unsigned int dma_bandwidth);
 #else
 static inline int hda_sdw_bpt_open(struct device *dev, int link_id,
 				   struct hdac_ext_stream **bpt_tx_stream,
@@ -64,6 +66,11 @@ static inline int hda_sdw_bpt_close(struct device *dev, struct hdac_ext_stream *
 	WARN_ONCE(1, "SoundWire BPT is disabled");
 	return -EOPNOTSUPP;
 }
+
+static inline unsigned int hda_sdw_bpt_get_buf_size_alignment(unsigned int dma_bandwidth)
+{
+	return 0;
+}
 #endif
 
 #endif /* __HDA_SDW_BPT_H */

sound/soc/sof/intel/hda-sdw-bpt.c

@@ -10,6 +10,7 @@
  * Hardware interface for SoundWire BPT support with HDA DMA
  */
 
+#include <linux/lcm.h>
 #include <sound/hdaudio_ext.h>
 #include <sound/hda-mlink.h>
 #include <sound/hda-sdw-bpt.h>
@@ -247,6 +248,18 @@ static int hda_sdw_bpt_dma_disable(struct device *dev, struct hdac_ext_stream *s
 	return ret;
 }
 
+#define FIFO_ALIGNMENT	64
+
+unsigned int hda_sdw_bpt_get_buf_size_alignment(unsigned int dma_bandwidth)
+{
+	unsigned int num_channels = DIV_ROUND_UP(dma_bandwidth, BPT_FREQUENCY * 32);
+	unsigned int data_block = num_channels * 4;
+	unsigned int alignment = lcm(data_block, FIFO_ALIGNMENT);
+
+	return alignment;
+}
+EXPORT_SYMBOL_NS(hda_sdw_bpt_get_buf_size_alignment, "SND_SOC_SOF_INTEL_HDA_SDW_BPT");
+
 int hda_sdw_bpt_open(struct device *dev, int link_id, struct hdac_ext_stream **bpt_tx_stream,
 		     struct snd_dma_buffer *dmab_tx_bdl, u32 bpt_tx_num_bytes,
 		     u32 tx_dma_bandwidth, struct hdac_ext_stream **bpt_rx_stream,