diff options
Diffstat (limited to 'sound/soc/jz4740/jz4740-i2s.c')
| -rw-r--r-- | sound/soc/jz4740/jz4740-i2s.c | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/sound/soc/jz4740/jz4740-i2s.c b/sound/soc/jz4740/jz4740-i2s.c index c4c1e89b47c1..83cb81999c6f 100644 --- a/sound/soc/jz4740/jz4740-i2s.c +++ b/sound/soc/jz4740/jz4740-i2s.c @@ -55,7 +55,8 @@ #define JZ_AIC_CTRL_MONO_TO_STEREO BIT(11) #define JZ_AIC_CTRL_SWITCH_ENDIANNESS BIT(10) #define JZ_AIC_CTRL_SIGNED_TO_UNSIGNED BIT(9) -#define JZ_AIC_CTRL_FLUSH BIT(8) +#define JZ_AIC_CTRL_TFLUSH BIT(8) +#define JZ_AIC_CTRL_RFLUSH BIT(7) #define JZ_AIC_CTRL_ENABLE_ROR_INT BIT(6) #define JZ_AIC_CTRL_ENABLE_TUR_INT BIT(5) #define JZ_AIC_CTRL_ENABLE_RFS_INT BIT(4) @@ -90,6 +91,8 @@ enum jz47xx_i2s_version { struct i2s_soc_info { enum jz47xx_i2s_version version; struct snd_soc_dai_driver *dai; + + bool shared_fifo_flush; }; struct jz4740_i2s { @@ -116,19 +119,44 @@ static inline void jz4740_i2s_write(const struct jz4740_i2s *i2s, writel(value, i2s->base + reg); } +static inline void jz4740_i2s_set_bits(const struct jz4740_i2s *i2s, + unsigned int reg, uint32_t bits) +{ + uint32_t value = jz4740_i2s_read(i2s, reg); + value |= bits; + jz4740_i2s_write(i2s, reg, value); +} + static int jz4740_i2s_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { struct jz4740_i2s *i2s = snd_soc_dai_get_drvdata(dai); - uint32_t conf, ctrl; + uint32_t conf; int ret; + /* + * When we can flush FIFOs independently, only flush the FIFO + * that is starting up. We can do this when the DAI is active + * because it does not disturb other active substreams. + */ + if (!i2s->soc_info->shared_fifo_flush) { + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_TFLUSH); + else + jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_RFLUSH); + } + if (snd_soc_dai_active(dai)) return 0; - ctrl = jz4740_i2s_read(i2s, JZ_REG_AIC_CTRL); - ctrl |= JZ_AIC_CTRL_FLUSH; - jz4740_i2s_write(i2s, JZ_REG_AIC_CTRL, ctrl); + /* + * When there is a shared flush bit for both FIFOs, the TFLUSH + * bit flushes both FIFOs. Flushing while the DAI is active would + * cause FIFO underruns in other active substreams so we have to + * guard this behind the snd_soc_dai_active() check. + */ + if (i2s->soc_info->shared_fifo_flush) + jz4740_i2s_set_bits(i2s, JZ_REG_AIC_CTRL, JZ_AIC_CTRL_TFLUSH); ret = clk_prepare_enable(i2s->clk_i2s); if (ret) @@ -443,6 +471,7 @@ static struct snd_soc_dai_driver jz4740_i2s_dai = { static const struct i2s_soc_info jz4740_i2s_soc_info = { .version = JZ_I2S_JZ4740, .dai = &jz4740_i2s_dai, + .shared_fifo_flush = true, }; static const struct i2s_soc_info jz4760_i2s_soc_info = { |