diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0566-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0566-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0566-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch b/target/linux/brcm2708/patches-4.4/0566-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch new file mode 100644 index 0000000..e435718 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0566-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch @@ -0,0 +1,101 @@ +From b97a67a14e5c5904b84e52150e0d13da794fc9d7 Mon Sep 17 00:00:00 2001 +From: gtrainavicius <gtrainavicius@users.noreply.github.com> +Date: Tue, 10 Jan 2017 21:59:39 +0200 +Subject: [PATCH] bcm2835-i2s: Changes for allowing asymmetric sample formats. + (#1783) + +This is achieved by making changes only to the requested +stream direction format, keeping the other stream direction +configuration intact. + +Signed-off-by: Giedrius Trainavicius <giedrius@blokas.io> +--- + sound/soc/bcm/bcm2835-i2s.c | 54 +++++++++++++++++++++++++++++++-------------- + 1 file changed, 38 insertions(+), 16 deletions(-) + +diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c +index aedb01f..d2b0801 100644 +--- a/sound/soc/bcm/bcm2835-i2s.c ++++ b/sound/soc/bcm/bcm2835-i2s.c +@@ -310,6 +310,7 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, + unsigned int sampling_rate = params_rate(params); + unsigned int data_length, data_delay, bclk_ratio; + unsigned int ch1pos, ch2pos, mode, format; ++ unsigned int previous_ftxp, previous_frxp; + unsigned int mash = BCM2835_CLK_MASH_1; + unsigned int divi, divf, target_frequency; + int clk_src = -1; +@@ -320,6 +321,7 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, + bool frame_master = (master == SND_SOC_DAIFMT_CBS_CFS + || master == SND_SOC_DAIFMT_CBM_CFS); + uint32_t csreg; ++ bool packed; + + /* + * If a stream is already enabled, +@@ -465,26 +467,46 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream, + return -EINVAL; + } + +- /* +- * Set format for both streams. +- * We cannot set another frame length +- * (and therefore word length) anyway, +- * so the format will be the same. +- */ +- regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format); +- regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format); ++ /* Set the format for the matching stream direction. */ ++ switch (substream->stream) { ++ case SNDRV_PCM_STREAM_PLAYBACK: ++ regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format); ++ break; ++ case SNDRV_PCM_STREAM_CAPTURE: ++ regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format); ++ break; ++ default: ++ return -EINVAL; ++ } + + /* Setup the I2S mode */ ++ /* Keep existing FTXP and FRXP values. */ ++ regmap_read(dev->i2s_regmap, BCM2835_I2S_MODE_A_REG, &mode); ++ ++ previous_ftxp = mode & BCM2835_I2S_FTXP; ++ previous_frxp = mode & BCM2835_I2S_FRXP; ++ + mode = 0; + +- if (data_length <= 16) { +- /* +- * Use frame packed mode (2 channels per 32 bit word) +- * We cannot set another frame length in the second stream +- * (and therefore word length) anyway, +- * so the format will be the same. +- */ +- mode |= BCM2835_I2S_FTXP | BCM2835_I2S_FRXP; ++ /* ++ * Retain the frame packed mode (2 channels per 32 bit word) ++ * of the other direction stream intact. The formats of each ++ * direction can be different as long as the frame length is ++ * shared for both. ++ */ ++ packed = data_length <= 16; ++ ++ switch (substream->stream) { ++ case SNDRV_PCM_STREAM_PLAYBACK: ++ mode |= previous_frxp; ++ mode |= packed ? BCM2835_I2S_FTXP : 0; ++ break; ++ case SNDRV_PCM_STREAM_CAPTURE: ++ mode |= previous_ftxp; ++ mode |= packed ? BCM2835_I2S_FRXP : 0; ++ break; ++ default: ++ return -EINVAL; + } + + mode |= BCM2835_I2S_FLEN(bclk_ratio - 1); +-- +2.1.4 + |