brcm2708: add linux 4.9 support

Patches from Raspberry Pi repo:
https://github.com/raspberrypi/linux/commits/rpi-4.9.y

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/target/linux/brcm2708/patches-4.9/0121-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch b/target/linux/brcm2708/patches-4.9/0121-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch
new file mode 100644
index 0000000000..0cc0f8848d
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.9/0121-bcm2835-i2s-Changes-for-allowing-asymmetric-sample-f.patch
@@ -0,0 +1,89 @@
+From 425ee76116894c97d5d97ad4883eb2612b8692f3 Mon Sep 17 00:00:00 2001
+From: Giedrius Trainavicius <giedrius@blokas.io>
+Date: Sun, 8 Jan 2017 15:58:54 +0200
+Subject: [PATCH] bcm2835-i2s: Changes for allowing asymmetric sample formats.
+
+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
+@@ -237,7 +237,9 @@ 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;
+ 	uint32_t csreg;
++	bool packed;
+ 
+ 	/*
+ 	 * If a stream is already enabled,
+@@ -320,26 +322,46 @@ 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);