ASoC: rockchip: add support for i2s-tdm controller

This commit adds support for the rockchip i2s-tdm controller,
which enables audio output on the following rockchip SoCs:
- px30
- rk1808
- rk3308
- rk3566
- rk3568
- rv1126

This is a cleaned up version of the downstream vendor kernel's
driver. It can be enabled through the SND_SOC_ROCKCHIP_I2S_TDM
configuration option.
Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
Link: https://lore.kernel.org/r/20211001171531.178775-2-frattaroli.nicolas@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

MAINTAINERS

@@ -16108,6 +16108,12 @@ F:	Documentation/ABI/*/sysfs-driver-hid-roccat*
 F:	drivers/hid/hid-roccat*
 F:	include/linux/hid-roccat*
 
+ROCKCHIP I2S TDM DRIVER
+M:	Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
+L:	linux-rockchip@lists.infradead.org
+S:	Maintained
+F:	sound/soc/rockchip/rockchip_i2s_tdm.*
+
 ROCKCHIP ISP V1 DRIVER
 M:	Helen Koike <helen.koike@collabora.com>
 M:	Dafna Hirschfeld <dafna.hirschfeld@collabora.com>

sound/soc/rockchip/Kconfig

@@ -16,6 +16,17 @@ config SND_SOC_ROCKCHIP_I2S
 	  Rockchip I2S device. The device supports upto maximum of
 	  8 channels each for play and record.
 
+config SND_SOC_ROCKCHIP_I2S_TDM
+	tristate "Rockchip I2S/TDM Device Driver"
+	depends on HAVE_CLK && SND_SOC_ROCKCHIP
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	help
+	  Say Y or M if you want to add support for the I2S/TDM driver for
+	  Rockchip I2S/TDM devices, found in Rockchip SoCs. These devices
+	  interface between the AHB bus and the I2S bus, and support up to a
+	  maximum of 8 channels each for playback and recording.
+
+
 config SND_SOC_ROCKCHIP_PDM
 	tristate "Rockchip PDM Controller Driver"
 	depends on HAVE_CLK && SND_SOC_ROCKCHIP

sound/soc/rockchip/Makefile

 # SPDX-License-Identifier: GPL-2.0
 # ROCKCHIP Platform Support
 snd-soc-rockchip-i2s-objs := rockchip_i2s.o
+snd-soc-rockchip-i2s-tdm-objs := rockchip_i2s_tdm.o
 snd-soc-rockchip-pcm-objs := rockchip_pcm.o
 snd-soc-rockchip-pdm-objs := rockchip_pdm.o
 snd-soc-rockchip-spdif-objs := rockchip_spdif.o
 
 obj-$(CONFIG_SND_SOC_ROCKCHIP_I2S) += snd-soc-rockchip-i2s.o snd-soc-rockchip-pcm.o
+obj-$(CONFIG_SND_SOC_ROCKCHIP_I2S_TDM) += snd-soc-rockchip-i2s-tdm.o
 obj-$(CONFIG_SND_SOC_ROCKCHIP_PDM) += snd-soc-rockchip-pdm.o
 obj-$(CONFIG_SND_SOC_ROCKCHIP_SPDIF) += snd-soc-rockchip-spdif.o