[alsa-devel] Applied "ASoC: davinci-mcasp: Get rid of bclk_lrclk_ratio in private data" to the asoc tree

[Mark Brown]

The patch

   ASoC: davinci-mcasp: Get rid of bclk_lrclk_ratio in private data

has been applied to the asoc tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 14a998be08e5286741021d3c81cc81e8d6d8a270 Mon Sep 17 00:00:00 2001
From: Jyri Sarha <jsarha at ti.com>
Date: Thu, 17 Sep 2015 10:39:05 +0300
Subject: [PATCH] ASoC: davinci-mcasp: Get rid of bclk_lrclk_ratio in private
 data

The slot_width is for essentially same thing. Instead of storing
bclk_lrclk_ratio, just store the slot_width. Comments has been updated
accordingly and some variable names changed to more descriptive.

Signed-off-by: Jyri Sarha <jsarha at ti.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/davinci/davinci-mcasp.c | 56 ++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 25 deletions(-)

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index fa47a39..452f2a3 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -87,7 +87,6 @@ struct davinci_mcasp {
 	u8	*serial_dir;
 	u8	version;
 	u8	bclk_div;
-	u16	bclk_lrclk_ratio;
 	int	streams;
 	u32	irq_request[2];
 	int	dma_request[2];
@@ -558,8 +557,21 @@ static int __davinci_mcasp_set_clkdiv(struct snd_soc_dai *dai, int div_id,
 			mcasp->bclk_div = div;
 		break;
 
-	case 2:		/* BCLK/LRCLK ratio */
-		mcasp->bclk_lrclk_ratio = div;
+	case 2:	/*
+		 * BCLK/LRCLK ratio descries how many bit-clock cycles
+		 * fit into one frame. The clock ratio is given for a
+		 * full period of data (for I2S format both left and
+		 * right channels), so it has to be divided by number
+		 * of tdm-slots (for I2S - divided by 2).
+		 * Instead of storing this ratio, we calculate a new
+		 * tdm_slot width by dividing the the ratio by the
+		 * number of configured tdm slots.
+		 */
+		mcasp->slot_width = div / mcasp->tdm_slots;
+		if (div % mcasp->tdm_slots)
+			dev_warn(mcasp->dev,
+				 "%s(): BCLK/LRCLK %d is not divisible by %d tdm slots",
+				 __func__, div, mcasp->tdm_slots);
 		break;
 
 	default:
@@ -677,11 +689,13 @@ static int davinci_mcasp_set_tdm_slot(struct snd_soc_dai *dai,
 }
 
 static int davinci_config_channel_size(struct davinci_mcasp *mcasp,
-				       int word_length)
+				       int sample_width)
 {
 	u32 fmt;
-	u32 tx_rotate = (word_length / 4) & 0x7;
-	u32 mask = (1ULL << word_length) - 1;
+	u32 tx_rotate = (sample_width / 4) & 0x7;
+	u32 mask = (1ULL << sample_width) - 1;
+	u32 slot_width = sample_width;
+
 	/*
 	 * For captured data we should not rotate, inversion and masking is
 	 * enoguh to get the data to the right position:
@@ -694,31 +708,23 @@ static int davinci_config_channel_size(struct davinci_mcasp *mcasp,
 	u32 rx_rotate = 0;
 
 	/*
-	 * if s BCLK-to-LRCLK ratio has been configured via the set_clkdiv()
-	 * callback, take it into account here. That allows us to for example
-	 * send 32 bits per channel to the codec, while only 16 of them carry
-	 * audio payload.
-	 * The clock ratio is given for a full period of data (for I2S format
-	 * both left and right channels), so it has to be divided by number of
-	 * tdm-slots (for I2S - divided by 2).
+	 * Setting the tdm slot width either with set_clkdiv() or
+	 * set_tdm_slot() allows us to for example send 32 bits per
+	 * channel to the codec, while only 16 of them carry audio
+	 * payload.
 	 */
-	if (mcasp->bclk_lrclk_ratio) {
-		u32 slot_length = mcasp->bclk_lrclk_ratio / mcasp->tdm_slots;
-
+	if (mcasp->slot_width) {
 		/*
-		 * When we have more bclk then it is needed for the data, we
-		 * need to use the rotation to move the received samples to have
-		 * correct alignment.
+		 * When we have more bclk then it is needed for the
+		 * data, we need to use the rotation to move the
+		 * received samples to have correct alignment.
 		 */
-		rx_rotate = (slot_length - word_length) / 4;
-		word_length = slot_length;
-	} else if (mcasp->slot_width) {
-		rx_rotate = (mcasp->slot_width - word_length) / 4;
-		word_length = mcasp->slot_width;
+		slot_width = mcasp->slot_width;
+		rx_rotate = (slot_width - sample_width) / 4;
 	}
 
 	/* mapping of the XSSZ bit-field as described in the datasheet */
-	fmt = (word_length >> 1) - 1;
+	fmt = (slot_width >> 1) - 1;
 
 	if (mcasp->op_mode != DAVINCI_MCASP_DIT_MODE) {
 		mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, RXSSZ(fmt),
-- 
2.5.0