Add audio support for LPC32XX CPUs

Merge series from Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>:

This pach set is to bring back audio to machines with a LPC32XX CPU.
The legacy LPC32XX SoC used to have audio spport in linux 2.6.27.
The support was dropped due to lack of interest from mainaeners.

Documentation/devicetree/bindings/sound/nxp,lpc3220-i2s.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/nxp,lpc3220-i2s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP LPC32XX I2S Controller
+
+description:
+  The I2S controller in LPC32XX SoCs, ASoC DAI.
+
+maintainers:
+  - J.M.B. Downing <jonathan.downing@nautel.com>
+  - Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    enum:
+      - nxp,lpc3220-i2s
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: input clock of the peripheral.
+
+  dmas:
+    items:
+      - description: RX DMA Channel
+      - description: TX DMA Channel
+
+  dma-names:
+    items:
+      - const: rx
+      - const: tx
+
+  "#sound-dai-cells":
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - dmas
+  - dma-names
+  - '#sound-dai-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/lpc32xx-clock.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2s@20094000 {
+      compatible = "nxp,lpc3220-i2s";
+      reg = <0x20094000 0x1000>;
+      interrupts = <22 IRQ_TYPE_LEVEL_HIGH>;
+      clocks = <&clk LPC32XX_CLK_I2S0>;
+      dmas = <&dma 0 1>, <&dma 13 1>;
+      dma-names = "rx", "tx";
+      #sound-dai-cells = <0>;
+    };
+
+...

MAINTAINERS

@@ -8909,6 +8909,16 @@ S:	Maintained
 F:	sound/soc/fsl/fsl*
 F:	sound/soc/fsl/imx*
 
+FREESCALE SOC LPC32XX SOUND DRIVERS
+M:	J.M.B. Downing <jonathan.downing@nautel.com>
+M:	Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
+R:	Vladimir Zapolskiy <vz@mleia.com>
+L:	alsa-devel@alsa-project.org (moderated for non-subscribers)
+L:	linuxppc-dev@lists.ozlabs.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/sound/nxp,lpc3220-i2s.yaml
+F:	sound/soc/fsl/lpc3xxx-*
+
 FREESCALE SOC SOUND QMC DRIVER
 M:	Herve Codina <herve.codina@bootlin.com>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)

sound/soc/fsl/Kconfig

@@ -131,6 +131,13 @@ config SND_SOC_FSL_RPMSG
 	  This option is only useful for out-of-tree drivers since
 	  in-tree drivers select it automatically.
 
+config SND_SOC_FSL_LPC3XXX
+	tristate "SoC Audio for NXP LPC32XX CPUs"
+	depends on ARCH_LPC32XX || COMPILE_TEST
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	help
+	  Say Y or M if you want to add support for the LPC3XXX I2S interface.
+
 config SND_SOC_IMX_PCM_DMA
 	tristate
 	select SND_SOC_GENERIC_DMAENGINE_PCM

sound/soc/fsl/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_SND_SOC_P1022_RDK) += snd-soc-p1022-rdk.o
 snd-soc-fsl-audmix-y := fsl_audmix.o
 snd-soc-fsl-asoc-card-y := fsl-asoc-card.o
 snd-soc-fsl-asrc-y := fsl_asrc.o fsl_asrc_dma.o
+snd-soc-fsl-lpc3xxx-y := lpc3xxx-pcm.o lpc3xxx-i2s.o
 snd-soc-fsl-sai-y := fsl_sai.o
 snd-soc-fsl-ssi-y := fsl_ssi.o
 snd-soc-fsl-ssi-$(CONFIG_DEBUG_FS) += fsl_ssi_dbg.o
@@ -29,6 +30,7 @@ snd-soc-fsl-qmc-audio-y := fsl_qmc_audio.o
 obj-$(CONFIG_SND_SOC_FSL_AUDMIX) += snd-soc-fsl-audmix.o
 obj-$(CONFIG_SND_SOC_FSL_ASOC_CARD) += snd-soc-fsl-asoc-card.o
 obj-$(CONFIG_SND_SOC_FSL_ASRC) += snd-soc-fsl-asrc.o
+obj-$(CONFIG_SND_SOC_FSL_LPC3XXX) += snd-soc-fsl-lpc3xxx.o
 obj-$(CONFIG_SND_SOC_FSL_SAI) += snd-soc-fsl-sai.o
 obj-$(CONFIG_SND_SOC_FSL_SSI) += snd-soc-fsl-ssi.o
 obj-$(CONFIG_SND_SOC_FSL_SPDIF) += snd-soc-fsl-spdif.o

sound/soc/fsl/lpc3xxx-i2s.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Author: Kevin Wells <kevin.wells@nxp.com>
+ *
+ * Copyright (C) 2008 NXP Semiconductors
+ * Copyright 2023 Timesys Corporation <piotr.wojtaszczyk@timesys.com>
+ */
+
+#ifndef __SOUND_SOC_LPC3XXX_I2S_H
+#define __SOUND_SOC_LPC3XXX_I2S_H
+
+#include <linux/types.h>
+#include <linux/regmap.h>
+
+struct lpc3xxx_i2s_info {
+	struct device *dev;
+	struct clk *clk;
+	struct mutex lock; /* To serialize user-space access */
+	struct regmap *regs;
+	u32 streams_in_use;
+	u32 clkrate;
+	int freq;
+	struct snd_dmaengine_dai_dma_data playback_dma_config;
+	struct snd_dmaengine_dai_dma_data capture_dma_config;
+};
+
+int lpc3xxx_pcm_register(struct platform_device *pdev);
+
+/* I2S controller register offsets */
+#define LPC3XXX_REG_I2S_DAO		0x00
+#define LPC3XXX_REG_I2S_DAI		0x04
+#define LPC3XXX_REG_I2S_TX_FIFO	0x08
+#define LPC3XXX_REG_I2S_RX_FIFO	0x0C
+#define LPC3XXX_REG_I2S_STAT	0x10
+#define LPC3XXX_REG_I2S_DMA0	0x14
+#define LPC3XXX_REG_I2S_DMA1	0x18
+#define LPC3XXX_REG_I2S_IRQ		0x1C
+#define LPC3XXX_REG_I2S_TX_RATE	0x20
+#define LPC3XXX_REG_I2S_RX_RATE	0x24
+
+/* i2s_daO i2s_dai register definitions */
+#define LPC3XXX_I2S_WW8      FIELD_PREP(0x3, 0) /* Word width is 8bit */
+#define LPC3XXX_I2S_WW16     FIELD_PREP(0x3, 1) /* Word width is 16bit */
+#define LPC3XXX_I2S_WW32     FIELD_PREP(0x3, 3) /* Word width is 32bit */
+#define LPC3XXX_I2S_MONO     BIT(2)   /* Mono */
+#define LPC3XXX_I2S_STOP     BIT(3)   /* Stop, diables the access to FIFO, mutes the channel */
+#define LPC3XXX_I2S_RESET    BIT(4)   /* Reset the channel */
+#define LPC3XXX_I2S_WS_SEL   BIT(5)   /* Channel Master(0) or slave(1) mode select */
+#define LPC3XXX_I2S_WS_HP(s) FIELD_PREP(0x7FC0, s) /* Word select half period - 1 */
+#define LPC3XXX_I2S_MUTE     BIT(15)  /* Mute the channel, Transmit channel only */
+
+#define LPC3XXX_I2S_WW32_HP  0x1f /* Word select half period for 32bit word width */
+#define LPC3XXX_I2S_WW16_HP  0x0f /* Word select half period for 16bit word width */
+#define LPC3XXX_I2S_WW8_HP   0x7  /* Word select half period for 8bit word width */
+
+/* i2s_stat register definitions */
+#define LPC3XXX_I2S_IRQ_STAT     BIT(0)
+#define LPC3XXX_I2S_DMA0_REQ     BIT(1)
+#define LPC3XXX_I2S_DMA1_REQ     BIT(2)
+
+/* i2s_dma0 Configuration register definitions */
+#define LPC3XXX_I2S_DMA0_RX_EN     BIT(0)       /* Enable RX DMA1 */
+#define LPC3XXX_I2S_DMA0_TX_EN     BIT(1)       /* Enable TX DMA1 */
+#define LPC3XXX_I2S_DMA0_RX_DEPTH(s) FIELD_PREP(0xF00, s)  /* Set the DMA1 RX Request level */
+#define LPC3XXX_I2S_DMA0_TX_DEPTH(s) FIELD_PREP(0xF0000, s) /* Set the DMA1 TX Request level */
+
+/* i2s_dma1 Configuration register definitions */
+#define LPC3XXX_I2S_DMA1_RX_EN     BIT(0)       /* Enable RX DMA1 */
+#define LPC3XXX_I2S_DMA1_TX_EN     BIT(1)       /* Enable TX DMA1 */
+#define LPC3XXX_I2S_DMA1_RX_DEPTH(s) FIELD_PREP(0x700, s) /* Set the DMA1 RX Request level */
+#define LPC3XXX_I2S_DMA1_TX_DEPTH(s) FIELD_PREP(0x70000, s) /* Set the DMA1 TX Request level */
+
+/* i2s_irq register definitions */
+#define LPC3XXX_I2S_RX_IRQ_EN     BIT(0)       /* Enable RX IRQ */
+#define LPC3XXX_I2S_TX_IRQ_EN     BIT(1)       /* Enable TX IRQ */
+#define LPC3XXX_I2S_IRQ_RX_DEPTH(s)  FIELD_PREP(0xFF00, s)  /* valid values ar 0 to 7 */
+#define LPC3XXX_I2S_IRQ_TX_DEPTH(s)  FIELD_PREP(0xFF0000, s) /* valid values ar 0 to 7 */
+
+#endif

sound/soc/fsl/lpc3xxx-pcm.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Author: Kevin Wells <kevin.wells@nxp.com>
+//
+// Copyright (C) 2008 NXP Semiconductors
+// Copyright 2023 Timesys Corporation <piotr.wojtaszczyk@timesys.com>
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/amba/pl08x.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/soc.h>
+
+#include "lpc3xxx-i2s.h"
+
+#define STUB_FORMATS	(SNDRV_PCM_FMTBIT_S8 | \
+			SNDRV_PCM_FMTBIT_U8 | \
+			SNDRV_PCM_FMTBIT_S16_LE | \
+			SNDRV_PCM_FMTBIT_U16_LE | \
+			SNDRV_PCM_FMTBIT_S24_LE | \
+			SNDRV_PCM_FMTBIT_U24_LE | \
+			SNDRV_PCM_FMTBIT_S32_LE | \
+			SNDRV_PCM_FMTBIT_U32_LE | \
+			SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE)
+
+static const struct snd_pcm_hardware lpc3xxx_pcm_hardware = {
+	.info = (SNDRV_PCM_INFO_MMAP |
+		 SNDRV_PCM_INFO_MMAP_VALID |
+		 SNDRV_PCM_INFO_INTERLEAVED |
+		 SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		 SNDRV_PCM_INFO_PAUSE |
+		 SNDRV_PCM_INFO_RESUME),
+	.formats = STUB_FORMATS,
+	.period_bytes_min = 128,
+	.period_bytes_max = 2048,
+	.periods_min = 2,
+	.periods_max = 1024,
+	.buffer_bytes_max = 128 * 1024
+};
+
+static const struct snd_dmaengine_pcm_config lpc3xxx_dmaengine_pcm_config = {
+	.pcm_hardware = &lpc3xxx_pcm_hardware,
+	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+	.compat_filter_fn = pl08x_filter_id,
+	.prealloc_buffer_size = 128 * 1024,
+};
+
+const struct snd_soc_component_driver lpc3xxx_soc_platform_driver = {
+	.name = "lpc32xx-pcm",
+};
+
+int lpc3xxx_pcm_register(struct platform_device *pdev)
+{
+	int ret;
+
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, &lpc3xxx_dmaengine_pcm_config, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register dmaengine: %d\n", ret);
+		return ret;
+	}
+
+	return devm_snd_soc_register_component(&pdev->dev, &lpc3xxx_soc_platform_driver,
+					       NULL, 0);
+}
+EXPORT_SYMBOL(lpc3xxx_pcm_register);