[alsa-devel] [PATCH v4 0/9]ASoC: sun4i-i2s: Updates to the driver

[codekipper at gmail.com]

From: Marcus Cooper <codekipper at gmail.com>

Hi All,

here is a patch series to add some improvements to the sun4i-i2s driver
found whilst getting slave clocking and hdmi audio working on the newer
SoCs. As the LibreELEC project is progressing extremely well then there
has been some activity getting surround sound working and this is included.

The functionality included with the new patch set has been extended to
cover more sample resolutions, multi-lane data output for HDMI audio
and some bug fixes that have been discovered along the way.

I can see more usage of the tdm property since I last attempted to push
these patches and the examples currently in mainline sort of the opposite
to what I'm trying to achieve. When we first started looking at the i2s
driver, the codecs that we were using allowed for the frame width to be
determined based on the sampling resolution but in most use cases it
seems that a fixed width is required(my highest priority should be to get
HDMI audio support in). We're using the tdm property to override the old
way to calculate the frame width. What I've seen in what has already been
mainlined is that the i2s driver has a frame width that is fixed to 32
bits and this can be overridden using the tdm property.

I still need to investigate the FIFO syncing issues which i've not had a 
chance to change or address the concerns that broonie and wens brought up.
This change has been moved to the top of the patch stack.

BR,
CK

---
v4 changes compared to v3 are:
- Moved patches around so that the more controversial of patches are
  at the top of the stack.
- Added more details to commit messages.
- Fixed 20bit audio PCM format to use 4 bytes.
- Reduced number of flags used to indicate a new SoC.

v3 changes compared to v2 are:
 - added back slave mode changes
 - added back the use of tdm properties
 - changes to regmap and caching
 - removed loopback functionality
 - fixes to the channel offset mask

v2 changes compared to v1 are:
 - removed slave mode changes which didn't set mclk and bclk div.
 - removed use of tdm and now use a dedicated property.
 - fix commit message to better explain reason for sign extending
 - add divider calculations for newer SoCs.
 - add support for multi-lane i2s data output.
 - add support for 20, 24 and 32 bit samples.
 - add loopback property so blocks can be tested without a codec.


Marcus Cooper (9):
  ASoC: sun4i-i2s: Fix sun8i tx channel offset mask
  ASoC: sun4i-i2s: Add offset to RX channel select
  ASoC: sun4i-i2s: Add regmap field to sign extend sample
  ASoC: sun4i-i2s: Reduce quirks for sun8i-h3
  ASoC: sun4i-i2s: Add set_tdm_slot functionality
  ASoC: sun4i-i2s: Add multi-lane functionality
  ASoC: sun4i-i2s: Add multichannel functionality
  ASoc: sun4i-i2s: Add 20, 24 and 32 bit support
  ASoC: sun4i-i2s: Adjust regmap settings

 sound/soc/sunxi/sun4i-i2s.c | 242 ++++++++++++++++++++++++------------
 1 file changed, 164 insertions(+), 78 deletions(-)

-- 
2.21.0