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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.patch96
1 files changed, 96 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 0000000000..88c001cf81
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0566-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch
@@ -0,0 +1,96 @@
+From b7c0618121a4cf0efdcecb4e36ad0be0430be0b3 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(-)
+
+--- 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
+ 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
+ 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
+ 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);