ASoC: cygnus: Add Cygnus audio DMA driver

This patch adds Cygnus audio DMA driver. It supports playback
and capture modes and uses ringbuffers for data transfer.
Signed-off-by: Lori Hikichi <lhikichi@broadcom.com>
Signed-off-by: Simran Rai <ssimran@broadcom.com>
Reviewed-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Arun Parameswaran <arunp@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/bcm/Kconfig

@@ -7,3 +7,12 @@ config SND_BCM2835_SOC_I2S
 	  Say Y or M if you want to add support for codecs attached to
 	  the BCM2835 I2S interface. You will also need
 	  to select the audio interfaces to support below.
+
+config SND_SOC_CYGNUS
+	tristate "SoC platform audio for Broadcom Cygnus chips"
+	depends on ARCH_BCM_CYGNUS || COMPILE_TEST
+	help
+	  Say Y if you want to add support for ASoC audio on Broadcom
+	  Cygnus chips (bcm958300, bcm958305, bcm911360)
+
+	  If you don't know what to do here, say N.
\ No newline at end of file

sound/soc/bcm/Makefile

@@ -3,3 +3,8 @@ snd-soc-bcm2835-i2s-objs := bcm2835-i2s.o
 
 obj-$(CONFIG_SND_BCM2835_SOC_I2S) += snd-soc-bcm2835-i2s.o
 
+# CYGNUS Platform Support
+snd-soc-cygnus-objs := cygnus-pcm.o cygnus-ssp.o
+
+obj-$(CONFIG_SND_SOC_CYGNUS) += snd-soc-cygnus.o
+

sound/soc/bcm/cygnus-pcm.c

+/*
+ * Copyright (C) 2014-2015 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+
+#include "cygnus-ssp.h"
+
+/* Register offset needed for ASoC PCM module */
+
+#define INTH_R5F_STATUS_OFFSET     0x040
+#define INTH_R5F_CLEAR_OFFSET      0x048
+#define INTH_R5F_MASK_SET_OFFSET   0x050
+#define INTH_R5F_MASK_CLEAR_OFFSET 0x054
+
+#define BF_REARM_FREE_MARK_OFFSET 0x344
+#define BF_REARM_FULL_MARK_OFFSET 0x348
+
+/* Ring Buffer Ctrl Regs --- Start */
+/* AUD_FMM_BF_CTRL_SOURCECH_RINGBUF_X_RDADDR_REG_BASE */
+#define SRC_RBUF_0_RDADDR_OFFSET 0x500
+#define SRC_RBUF_1_RDADDR_OFFSET 0x518
+#define SRC_RBUF_2_RDADDR_OFFSET 0x530
+#define SRC_RBUF_3_RDADDR_OFFSET 0x548
+#define SRC_RBUF_4_RDADDR_OFFSET 0x560
+#define SRC_RBUF_5_RDADDR_OFFSET 0x578
+#define SRC_RBUF_6_RDADDR_OFFSET 0x590
+
+/* AUD_FMM_BF_CTRL_SOURCECH_RINGBUF_X_WRADDR_REG_BASE */
+#define SRC_RBUF_0_WRADDR_OFFSET 0x504
+#define SRC_RBUF_1_WRADDR_OFFSET 0x51c
+#define SRC_RBUF_2_WRADDR_OFFSET 0x534
+#define SRC_RBUF_3_WRADDR_OFFSET 0x54c
+#define SRC_RBUF_4_WRADDR_OFFSET 0x564
+#define SRC_RBUF_5_WRADDR_OFFSET 0x57c
+#define SRC_RBUF_6_WRADDR_OFFSET 0x594
+
+/* AUD_FMM_BF_CTRL_SOURCECH_RINGBUF_X_BASEADDR_REG_BASE */
+#define SRC_RBUF_0_BASEADDR_OFFSET 0x508
+#define SRC_RBUF_1_BASEADDR_OFFSET 0x520
+#define SRC_RBUF_2_BASEADDR_OFFSET 0x538
+#define SRC_RBUF_3_BASEADDR_OFFSET 0x550
+#define SRC_RBUF_4_BASEADDR_OFFSET 0x568
+#define SRC_RBUF_5_BASEADDR_OFFSET 0x580
+#define SRC_RBUF_6_BASEADDR_OFFSET 0x598
+
+/* AUD_FMM_BF_CTRL_SOURCECH_RINGBUF_X_ENDADDR_REG_BASE */
+#define SRC_RBUF_0_ENDADDR_OFFSET 0x50c
+#define SRC_RBUF_1_ENDADDR_OFFSET 0x524
+#define SRC_RBUF_2_ENDADDR_OFFSET 0x53c
+#define SRC_RBUF_3_ENDADDR_OFFSET 0x554
+#define SRC_RBUF_4_ENDADDR_OFFSET 0x56c
+#define SRC_RBUF_5_ENDADDR_OFFSET 0x584
+#define SRC_RBUF_6_ENDADDR_OFFSET 0x59c
+
+/* AUD_FMM_BF_CTRL_SOURCECH_RINGBUF_X_FREE_MARK_REG_BASE */
+#define SRC_RBUF_0_FREE_MARK_OFFSET 0x510
+#define SRC_RBUF_1_FREE_MARK_OFFSET 0x528
+#define SRC_RBUF_2_FREE_MARK_OFFSET 0x540
+#define SRC_RBUF_3_FREE_MARK_OFFSET 0x558
+#define SRC_RBUF_4_FREE_MARK_OFFSET 0x570
+#define SRC_RBUF_5_FREE_MARK_OFFSET 0x588
+#define SRC_RBUF_6_FREE_MARK_OFFSET 0x5a0
+
+/* AUD_FMM_BF_CTRL_DESTCH_RINGBUF_X_RDADDR_REG_BASE */
+#define DST_RBUF_0_RDADDR_OFFSET 0x5c0
+#define DST_RBUF_1_RDADDR_OFFSET 0x5d8
+#define DST_RBUF_2_RDADDR_OFFSET 0x5f0
+#define DST_RBUF_3_RDADDR_OFFSET 0x608
+#define DST_RBUF_4_RDADDR_OFFSET 0x620
+#define DST_RBUF_5_RDADDR_OFFSET 0x638
+
+/* AUD_FMM_BF_CTRL_DESTCH_RINGBUF_X_WRADDR_REG_BASE */
+#define DST_RBUF_0_WRADDR_OFFSET 0x5c4
+#define DST_RBUF_1_WRADDR_OFFSET 0x5dc
+#define DST_RBUF_2_WRADDR_OFFSET 0x5f4
+#define DST_RBUF_3_WRADDR_OFFSET 0x60c
+#define DST_RBUF_4_WRADDR_OFFSET 0x624
+#define DST_RBUF_5_WRADDR_OFFSET 0x63c
+
+/* AUD_FMM_BF_CTRL_DESTCH_RINGBUF_X_BASEADDR_REG_BASE */
+#define DST_RBUF_0_BASEADDR_OFFSET 0x5c8
+#define DST_RBUF_1_BASEADDR_OFFSET 0x5e0
+#define DST_RBUF_2_BASEADDR_OFFSET 0x5f8
+#define DST_RBUF_3_BASEADDR_OFFSET 0x610
+#define DST_RBUF_4_BASEADDR_OFFSET 0x628
+#define DST_RBUF_5_BASEADDR_OFFSET 0x640
+
+/* AUD_FMM_BF_CTRL_DESTCH_RINGBUF_X_ENDADDR_REG_BASE */
+#define DST_RBUF_0_ENDADDR_OFFSET 0x5cc
+#define DST_RBUF_1_ENDADDR_OFFSET 0x5e4
+#define DST_RBUF_2_ENDADDR_OFFSET 0x5fc
+#define DST_RBUF_3_ENDADDR_OFFSET 0x614
+#define DST_RBUF_4_ENDADDR_OFFSET 0x62c
+#define DST_RBUF_5_ENDADDR_OFFSET 0x644
+
+/* AUD_FMM_BF_CTRL_DESTCH_RINGBUF_X_FULL_MARK_REG_BASE */
+#define DST_RBUF_0_FULL_MARK_OFFSET 0x5d0
+#define DST_RBUF_1_FULL_MARK_OFFSET 0x5e8
+#define DST_RBUF_2_FULL_MARK_OFFSET 0x600
+#define DST_RBUF_3_FULL_MARK_OFFSET 0x618
+#define DST_RBUF_4_FULL_MARK_OFFSET 0x630
+#define DST_RBUF_5_FULL_MARK_OFFSET 0x648
+/* Ring Buffer Ctrl Regs --- End */
+
+/* Error Status Regs --- Start */
+/* AUD_FMM_BF_ESR_ESRX_STATUS_REG_BASE */
+#define ESR0_STATUS_OFFSET 0x900
+#define ESR1_STATUS_OFFSET 0x918
+#define ESR2_STATUS_OFFSET 0x930
+#define ESR3_STATUS_OFFSET 0x948
+#define ESR4_STATUS_OFFSET 0x960
+
+/* AUD_FMM_BF_ESR_ESRX_STATUS_CLEAR_REG_BASE */
+#define ESR0_STATUS_CLR_OFFSET 0x908
+#define ESR1_STATUS_CLR_OFFSET 0x920
+#define ESR2_STATUS_CLR_OFFSET 0x938
+#define ESR3_STATUS_CLR_OFFSET 0x950
+#define ESR4_STATUS_CLR_OFFSET 0x968
+
+/* AUD_FMM_BF_ESR_ESRX_MASK_REG_BASE */
+#define ESR0_MASK_STATUS_OFFSET 0x90c
+#define ESR1_MASK_STATUS_OFFSET 0x924
+#define ESR2_MASK_STATUS_OFFSET 0x93c
+#define ESR3_MASK_STATUS_OFFSET 0x954
+#define ESR4_MASK_STATUS_OFFSET 0x96c
+
+/* AUD_FMM_BF_ESR_ESRX_MASK_SET_REG_BASE */
+#define ESR0_MASK_SET_OFFSET 0x910
+#define ESR1_MASK_SET_OFFSET 0x928
+#define ESR2_MASK_SET_OFFSET 0x940
+#define ESR3_MASK_SET_OFFSET 0x958
+#define ESR4_MASK_SET_OFFSET 0x970
+
+/* AUD_FMM_BF_ESR_ESRX_MASK_CLEAR_REG_BASE */
+#define ESR0_MASK_CLR_OFFSET 0x914
+#define ESR1_MASK_CLR_OFFSET 0x92c
+#define ESR2_MASK_CLR_OFFSET 0x944
+#define ESR3_MASK_CLR_OFFSET 0x95c
+#define ESR4_MASK_CLR_OFFSET 0x974
+/* Error Status Regs --- End */
+
+#define R5F_ESR0_SHIFT  0    /* esr0 = fifo underflow */
+#define R5F_ESR1_SHIFT  1    /* esr1 = ringbuf underflow */
+#define R5F_ESR2_SHIFT  2    /* esr2 = ringbuf overflow */
+#define R5F_ESR3_SHIFT  3    /* esr3 = freemark */
+#define R5F_ESR4_SHIFT  4    /* esr4 = fullmark */
+
+
+/* Mask for R5F register.  Set all relevant interrupt for playback handler */
+#define ANY_PLAYBACK_IRQ  (BIT(R5F_ESR0_SHIFT) | \
+			   BIT(R5F_ESR1_SHIFT) | \
+			   BIT(R5F_ESR3_SHIFT))
+
+/* Mask for R5F register.  Set all relevant interrupt for capture handler */
+#define ANY_CAPTURE_IRQ   (BIT(R5F_ESR2_SHIFT) | BIT(R5F_ESR4_SHIFT))
+
+/*
+ * PERIOD_BYTES_MIN is the number of bytes to at which the interrupt will tick.
+ * This number should be a multiple of 256. Minimum value is 256
+ */
+#define PERIOD_BYTES_MIN 0x100
+
+static const struct snd_pcm_hardware cygnus_pcm_hw = {
+	.info = SNDRV_PCM_INFO_MMAP |
+			SNDRV_PCM_INFO_MMAP_VALID |
+			SNDRV_PCM_INFO_INTERLEAVED,
+	.formats = SNDRV_PCM_FMTBIT_S16_LE |
+			SNDRV_PCM_FMTBIT_S32_LE,
+
+	/* A period is basically an interrupt */
+	.period_bytes_min = PERIOD_BYTES_MIN,
+	.period_bytes_max = 0x10000,
+
+	/* period_min/max gives range of approx interrupts per buffer */
+	.periods_min = 2,
+	.periods_max = 8,
+
+	/*
+	 * maximum buffer size in bytes = period_bytes_max * periods_max
+	 * We allocate this amount of data for each enabled channel
+	 */
+	.buffer_bytes_max = 4 * 0x8000,
+};
+
+static u64 cygnus_dma_dmamask = DMA_BIT_MASK(32);
+
+static struct cygnus_aio_port *cygnus_dai_get_dma_data(
+				struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *soc_runtime = substream->private_data;
+
+	return snd_soc_dai_get_dma_data(soc_runtime->cpu_dai, substream);
+}
+
+static void ringbuf_set_initial(void __iomem *audio_io,
+		struct ringbuf_regs *p_rbuf,
+		bool is_playback,
+		u32 start,
+		u32 periodsize,
+		u32 bufsize)
+{
+	u32 initial_rd;
+	u32 initial_wr;
+	u32 end;
+	u32 fmark_val; /* free or full mark */
+
+	p_rbuf->period_bytes = periodsize;
+	p_rbuf->buf_size = bufsize;
+
+	if (is_playback) {
+		/* Set the pointers to indicate full (flip uppermost bit) */
+		initial_rd = start;
+		initial_wr = initial_rd ^ BIT(31);
+	} else {
+		/* Set the pointers to indicate empty */
+		initial_wr = start;
+		initial_rd = initial_wr;
+	}
+
+	end = start + bufsize - 1;
+
+	/*
+	 * The interrupt will fire when free/full mark is *exceeded*
+	 * The fmark value must be multiple of PERIOD_BYTES_MIN so set fmark
+	 * to be PERIOD_BYTES_MIN less than the period size.
+	 */
+	fmark_val = periodsize - PERIOD_BYTES_MIN;
+
+	writel(start, audio_io + p_rbuf->baseaddr);
+	writel(end, audio_io + p_rbuf->endaddr);
+	writel(fmark_val, audio_io + p_rbuf->fmark);
+	writel(initial_rd, audio_io + p_rbuf->rdaddr);
+	writel(initial_wr, audio_io + p_rbuf->wraddr);
+}
+
+static int configure_ringbuf_regs(struct snd_pcm_substream *substream)
+{
+	struct cygnus_aio_port *aio;
+	struct ringbuf_regs *p_rbuf;
+	int status = 0;
+
+	aio = cygnus_dai_get_dma_data(substream);
+
+	/* Map the ssp portnum to a set of ring buffers. */
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		p_rbuf = &aio->play_rb_regs;
+
+		switch (aio->portnum) {
+		case 0:
+			*p_rbuf = RINGBUF_REG_PLAYBACK(0);
+			break;
+		case 1:
+			*p_rbuf = RINGBUF_REG_PLAYBACK(2);
+			break;
+		case 2:
+			*p_rbuf = RINGBUF_REG_PLAYBACK(4);
+			break;
+		case 3: /* SPDIF */
+			*p_rbuf = RINGBUF_REG_PLAYBACK(6);
+			break;
+		default:
+			status = -EINVAL;
+		}
+	} else {
+		p_rbuf = &aio->capture_rb_regs;
+
+		switch (aio->portnum) {
+		case 0:
+			*p_rbuf = RINGBUF_REG_CAPTURE(0);
+			break;
+		case 1:
+			*p_rbuf = RINGBUF_REG_CAPTURE(2);
+			break;
+		case 2:
+			*p_rbuf = RINGBUF_REG_CAPTURE(4);
+			break;
+		default:
+			status = -EINVAL;
+		}
+	}
+
+	return status;
+}
+
+static struct ringbuf_regs *get_ringbuf(struct snd_pcm_substream *substream)
+{
+	struct cygnus_aio_port *aio;
+	struct ringbuf_regs *p_rbuf = NULL;
+
+	aio = cygnus_dai_get_dma_data(substream);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		p_rbuf = &aio->play_rb_regs;
+	else
+		p_rbuf = &aio->capture_rb_regs;
+
+	return p_rbuf;
+}
+
+static void enable_intr(struct snd_pcm_substream *substream)
+{
+	struct cygnus_aio_port *aio;
+	u32 clear_mask;
+
+	aio = cygnus_dai_get_dma_data(substream);
+
+	/* The port number maps to the bit position to be cleared */
+	clear_mask = BIT(aio->portnum);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		/* Clear interrupt status before enabling them */
+		writel(clear_mask, aio->cygaud->audio + ESR0_STATUS_CLR_OFFSET);
+		writel(clear_mask, aio->cygaud->audio + ESR1_STATUS_CLR_OFFSET);
+		writel(clear_mask, aio->cygaud->audio + ESR3_STATUS_CLR_OFFSET);
+		/* Unmask the interrupts of the given port*/
+		writel(clear_mask, aio->cygaud->audio + ESR0_MASK_CLR_OFFSET);
+		writel(clear_mask, aio->cygaud->audio + ESR1_MASK_CLR_OFFSET);
+		writel(clear_mask, aio->cygaud->audio + ESR3_MASK_CLR_OFFSET);
+
+		writel(ANY_PLAYBACK_IRQ,
+			aio->cygaud->audio + INTH_R5F_MASK_CLEAR_OFFSET);
+	} else {
+		writel(clear_mask, aio->cygaud->audio + ESR2_STATUS_CLR_OFFSET);
+		writel(clear_mask, aio->cygaud->audio + ESR4_STATUS_CLR_OFFSET);
+		writel(clear_mask, aio->cygaud->audio + ESR2_MASK_CLR_OFFSET);
+		writel(clear_mask, aio->cygaud->audio + ESR4_MASK_CLR_OFFSET);
+
+		writel(ANY_CAPTURE_IRQ,
+			aio->cygaud->audio + INTH_R5F_MASK_CLEAR_OFFSET);
+	}
+
+}
+
+static void disable_intr(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct cygnus_aio_port *aio;
+	u32 set_mask;
+
+	aio = cygnus_dai_get_dma_data(substream);
+
+	dev_dbg(rtd->cpu_dai->dev, "%s on port %d\n", __func__, aio->portnum);
+
+	/* The port number maps to the bit position to be set */
+	set_mask = BIT(aio->portnum);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		/* Mask the interrupts of the given port*/
+		writel(set_mask, aio->cygaud->audio + ESR0_MASK_SET_OFFSET);
+		writel(set_mask, aio->cygaud->audio + ESR1_MASK_SET_OFFSET);
+		writel(set_mask, aio->cygaud->audio + ESR3_MASK_SET_OFFSET);
+	} else {
+		writel(set_mask, aio->cygaud->audio + ESR2_MASK_SET_OFFSET);
+		writel(set_mask, aio->cygaud->audio + ESR4_MASK_SET_OFFSET);
+	}
+
+}
+
+static int cygnus_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+		enable_intr(substream);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		disable_intr(substream);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static void cygnus_pcm_period_elapsed(struct snd_pcm_substream *substream)
+{
+	struct cygnus_aio_port *aio;
+	struct ringbuf_regs *p_rbuf = NULL;
+	u32 regval;
+
+	aio = cygnus_dai_get_dma_data(substream);
+
+	p_rbuf = get_ringbuf(substream);
+
+	/*
+	 * If free/full mark interrupt occurs, provide timestamp
+	 * to ALSA and update appropriate idx by period_bytes
+	 */
+	snd_pcm_period_elapsed(substream);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		/* Set the ring buffer to full */
+		regval = readl(aio->cygaud->audio + p_rbuf->rdaddr);
+		regval = regval ^ BIT(31);
+		writel(regval, aio->cygaud->audio + p_rbuf->wraddr);
+	} else {
+		/* Set the ring buffer to empty */
+		regval = readl(aio->cygaud->audio + p_rbuf->wraddr);
+		writel(regval, aio->cygaud->audio + p_rbuf->rdaddr);
+	}
+}
+
+/*
+ * ESR0/1/3 status  Description
+ *  0x1	I2S0_out port caused interrupt
+ *  0x2	I2S1_out port caused interrupt
+ *  0x4	I2S2_out port caused interrupt
+ *  0x8	SPDIF_out port caused interrupt
+ */
+static void handle_playback_irq(struct cygnus_audio *cygaud)
+{
+	void __iomem *audio_io;
+	u32 port;
+	u32 esr_status0, esr_status1, esr_status3;
+
+	audio_io = cygaud->audio;
+
+	/*
+	 * ESR status gets updates with/without interrupts enabled.
+	 * So, check the ESR mask, which provides interrupt enable/
+	 * disable status and use it to determine which ESR status
+	 * should be serviced.
+	 */
+	esr_status0 = readl(audio_io + ESR0_STATUS_OFFSET);
+	esr_status0 &= ~readl(audio_io + ESR0_MASK_STATUS_OFFSET);
+	esr_status1 = readl(audio_io + ESR1_STATUS_OFFSET);
+	esr_status1 &= ~readl(audio_io + ESR1_MASK_STATUS_OFFSET);
+	esr_status3 = readl(audio_io + ESR3_STATUS_OFFSET);
+	esr_status3 &= ~readl(audio_io + ESR3_MASK_STATUS_OFFSET);
+
+	for (port = 0; port < CYGNUS_MAX_PLAYBACK_PORTS; port++) {
+		u32 esrmask = BIT(port);
+
+		/*
+		 * Ringbuffer or FIFO underflow
+		 * If we get this interrupt then, it is also true that we have
+		 * not yet responded to the freemark interrupt.
+		 * Log a debug message.  The freemark handler below will
+		 * handle getting everything going again.
+		 */
+		if ((esrmask & esr_status1) || (esrmask & esr_status0)) {
+			dev_dbg(cygaud->dev,
+				"Underrun: esr0=0x%x, esr1=0x%x esr3=0x%x\n",
+				esr_status0, esr_status1, esr_status3);
+		}
+
+		/*
+		 * Freemark is hit. This is the normal interrupt.
+		 * In typical operation the read and write regs will be equal
+		 */
+		if (esrmask & esr_status3) {
+			struct snd_pcm_substream *playstr;
+
+			playstr = cygaud->portinfo[port].play_stream;
+			cygnus_pcm_period_elapsed(playstr);
+		}
+	}
+
+	/* Clear ESR interrupt */
+	writel(esr_status0, audio_io + ESR0_STATUS_CLR_OFFSET);
+	writel(esr_status1, audio_io + ESR1_STATUS_CLR_OFFSET);
+	writel(esr_status3, audio_io + ESR3_STATUS_CLR_OFFSET);
+	/* Rearm freemark logic by writing 1 to the correct bit */
+	writel(esr_status3, audio_io + BF_REARM_FREE_MARK_OFFSET);
+}
+
+/*
+ * ESR2/4 status  Description
+ *  0x1	I2S0_in port caused interrupt
+ *  0x2	I2S1_in port caused interrupt
+ *  0x4	I2S2_in port caused interrupt
+ */
+static void handle_capture_irq(struct cygnus_audio *cygaud)
+{
+	void __iomem *audio_io;
+	u32 port;
+	u32 esr_status2, esr_status4;
+
+	audio_io = cygaud->audio;
+
+	/*
+	 * ESR status gets updates with/without interrupts enabled.
+	 * So, check the ESR mask, which provides interrupt enable/
+	 * disable status and use it to determine which ESR status
+	 * should be serviced.
+	 */
+	esr_status2 = readl(audio_io + ESR2_STATUS_OFFSET);
+	esr_status2 &= ~readl(audio_io + ESR2_MASK_STATUS_OFFSET);
+	esr_status4 = readl(audio_io + ESR4_STATUS_OFFSET);
+	esr_status4 &= ~readl(audio_io + ESR4_MASK_STATUS_OFFSET);
+
+	for (port = 0; port < CYGNUS_MAX_CAPTURE_PORTS; port++) {
+		u32 esrmask = BIT(port);
+
+		/*
+		 * Ringbuffer or FIFO overflow
+		 * If we get this interrupt then, it is also true that we have
+		 * not yet responded to the fullmark interrupt.
+		 * Log a debug message.  The fullmark handler below will
+		 * handle getting everything going again.
+		 */
+		if (esrmask & esr_status2)
+			dev_dbg(cygaud->dev,
+				"Overflow: esr2=0x%x\n", esr_status2);
+
+		if (esrmask & esr_status4) {
+			struct snd_pcm_substream *capstr;
+
+			capstr = cygaud->portinfo[port].capture_stream;
+			cygnus_pcm_period_elapsed(capstr);
+		}
+	}
+
+	writel(esr_status2, audio_io + ESR2_STATUS_CLR_OFFSET);
+	writel(esr_status4, audio_io + ESR4_STATUS_CLR_OFFSET);
+	/* Rearm fullmark logic by writing 1 to the correct bit */
+	writel(esr_status4, audio_io + BF_REARM_FULL_MARK_OFFSET);
+}
+
+static irqreturn_t cygnus_dma_irq(int irq, void *data)
+{
+	u32 r5_status;
+	struct cygnus_audio *cygaud = data;
+
+	/*
+	 * R5 status bits	Description
+	 *  0		ESR0 (playback FIFO interrupt)
+	 *  1		ESR1 (playback rbuf interrupt)
+	 *  2		ESR2 (capture rbuf interrupt)
+	 *  3		ESR3 (Freemark play. interrupt)
+	 *  4		ESR4 (Fullmark capt. interrupt)
+	 */
+	r5_status = readl(cygaud->audio + INTH_R5F_STATUS_OFFSET);
+
+	if (!(r5_status & (ANY_PLAYBACK_IRQ | ANY_CAPTURE_IRQ)))
+		return IRQ_NONE;
+
+	/* If playback interrupt happened */
+	if (ANY_PLAYBACK_IRQ & r5_status) {
+		handle_playback_irq(cygaud);
+		writel(ANY_PLAYBACK_IRQ & r5_status,
+			cygaud->audio + INTH_R5F_CLEAR_OFFSET);
+	}
+
+	/* If  capture interrupt happened */
+	if (ANY_CAPTURE_IRQ & r5_status) {
+		handle_capture_irq(cygaud);
+		writel(ANY_CAPTURE_IRQ & r5_status,
+			cygaud->audio + INTH_R5F_CLEAR_OFFSET);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int cygnus_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct cygnus_aio_port *aio;
+	int ret;
+
+	aio = cygnus_dai_get_dma_data(substream);
+	if (!aio)
+		return -ENODEV;
+
+	dev_dbg(rtd->cpu_dai->dev, "%s port %d\n", __func__, aio->portnum);
+
+	snd_soc_set_runtime_hwparams(substream, &cygnus_pcm_hw);
+
+	ret = snd_pcm_hw_constraint_step(runtime, 0,
+		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, PERIOD_BYTES_MIN);
+	if (ret < 0)
+		return ret;
+
+	ret = snd_pcm_hw_constraint_step(runtime, 0,
+		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, PERIOD_BYTES_MIN);
+	if (ret < 0)
+		return ret;
+	/*
+	 * Keep track of which substream belongs to which port.
+	 * This info is needed by snd_pcm_period_elapsed() in irq_handler
+	 */
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		aio->play_stream = substream;
+	else
+		aio->capture_stream = substream;
+
+	return 0;
+}
+
+static int cygnus_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct cygnus_aio_port *aio;
+
+	aio = cygnus_dai_get_dma_data(substream);
+
+	dev_dbg(rtd->cpu_dai->dev, "%s  port %d\n", __func__, aio->portnum);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		aio->play_stream = NULL;
+	else
+		aio->capture_stream = NULL;
+
+	if (!aio->play_stream && !aio->capture_stream)
+		dev_dbg(rtd->cpu_dai->dev, "freed  port %d\n", aio->portnum);
+
+	return 0;
+}
+
+static int cygnus_pcm_hw_params(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct cygnus_aio_port *aio;
+	int ret = 0;
+
+	aio = cygnus_dai_get_dma_data(substream);
+	dev_dbg(rtd->cpu_dai->dev, "%s  port %d\n", __func__, aio->portnum);
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+	runtime->dma_bytes = params_buffer_bytes(params);
+
+	return ret;
+}
+
+static int cygnus_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct cygnus_aio_port *aio;
+
+	aio = cygnus_dai_get_dma_data(substream);
+	dev_dbg(rtd->cpu_dai->dev, "%s  port %d\n", __func__, aio->portnum);
+
+	snd_pcm_set_runtime_buffer(substream, NULL);
+	return 0;
+}
+
+static int cygnus_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct cygnus_aio_port *aio;
+	unsigned long bufsize, periodsize;
+	int ret = 0;
+	bool is_play;
+	u32 start;
+	struct ringbuf_regs *p_rbuf = NULL;
+
+	aio = cygnus_dai_get_dma_data(substream);
+	dev_dbg(rtd->cpu_dai->dev, "%s port %d\n", __func__, aio->portnum);
+
+	bufsize = snd_pcm_lib_buffer_bytes(substream);
+	periodsize = snd_pcm_lib_period_bytes(substream);
+
+	dev_dbg(rtd->cpu_dai->dev, "%s (buf_size %lu) (period_size %lu)\n",
+			__func__, bufsize, periodsize);
+
+	configure_ringbuf_regs(substream);
+
+	p_rbuf = get_ringbuf(substream);
+
+	start = runtime->dma_addr;
+
+	is_play = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ? 1 : 0;
+
+	ringbuf_set_initial(aio->cygaud->audio, p_rbuf, is_play, start,
+				periodsize, bufsize);
+
+	return ret;
+}
+
+static snd_pcm_uframes_t cygnus_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct cygnus_aio_port *aio;
+	unsigned int res = 0, cur = 0, base = 0;
+	struct ringbuf_regs *p_rbuf = NULL;
+
+	aio = cygnus_dai_get_dma_data(substream);
+
+	/*
+	 * Get the offset of the current read (for playack) or write
+	 * index (for capture).  Report this value back to the asoc framework.
+	 */
+	p_rbuf = get_ringbuf(substream);
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		cur = readl(aio->cygaud->audio + p_rbuf->rdaddr);
+	else
+		cur = readl(aio->cygaud->audio + p_rbuf->wraddr);
+
+	base = readl(aio->cygaud->audio + p_rbuf->baseaddr);
+
+	/*
+	 * Mask off the MSB of the rdaddr,wraddr and baseaddr
+	 * since MSB is not part of the address
+	 */
+	res = (cur & 0x7fffffff) - (base & 0x7fffffff);
+
+	return bytes_to_frames(substream->runtime, res);
+}
+
+static int cygnus_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
+{
+	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_dma_buffer *buf = &substream->dma_buffer;
+	size_t size;
+
+	size = cygnus_pcm_hw.buffer_bytes_max;
+
+	buf->dev.type = SNDRV_DMA_TYPE_DEV;
+	buf->dev.dev = pcm->card->dev;
+	buf->private_data = NULL;
+	buf->area = dma_alloc_coherent(pcm->card->dev, size,
+			&buf->addr, GFP_KERNEL);
+
+	dev_dbg(rtd->cpu_dai->dev, "%s: size 0x%zx @ %pK\n",
+				__func__, size, buf->area);
+
+	if (!buf->area) {
+		dev_err(rtd->cpu_dai->dev, "%s: dma_alloc failed\n", __func__);
+		return -ENOMEM;
+	}
+	buf->bytes = size;
+
+	return 0;
+}
+
+
+static const struct snd_pcm_ops cygnus_pcm_ops = {
+	.open		= cygnus_pcm_open,
+	.close		= cygnus_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= cygnus_pcm_hw_params,
+	.hw_free	= cygnus_pcm_hw_free,
+	.prepare	= cygnus_pcm_prepare,
+	.trigger	= cygnus_pcm_trigger,
+	.pointer	= cygnus_pcm_pointer,
+};
+
+static void cygnus_dma_free_dma_buffers(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_dma_buffer *buf;
+
+	substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
+	if (substream) {
+		buf = &substream->dma_buffer;
+		if (buf->area) {
+			dma_free_coherent(pcm->card->dev, buf->bytes,
+				buf->area, buf->addr);
+			buf->area = NULL;
+		}
+	}
+
+	substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
+	if (substream) {
+		buf = &substream->dma_buffer;
+		if (buf->area) {
+			dma_free_coherent(pcm->card->dev, buf->bytes,
+				buf->area, buf->addr);
+			buf->area = NULL;
+		}
+	}
+}
+
+static int cygnus_dma_new(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_card *card = rtd->card->snd_card;
+	struct snd_pcm *pcm = rtd->pcm;
+	int ret;
+
+	if (!card->dev->dma_mask)
+		card->dev->dma_mask = &cygnus_dma_dmamask;
+	if (!card->dev->coherent_dma_mask)
+		card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
+
+	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
+		ret = cygnus_pcm_preallocate_dma_buffer(pcm,
+				SNDRV_PCM_STREAM_PLAYBACK);
+		if (ret)
+			return ret;
+	}
+
+	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
+		ret = cygnus_pcm_preallocate_dma_buffer(pcm,
+				SNDRV_PCM_STREAM_CAPTURE);
+		if (ret) {
+			cygnus_dma_free_dma_buffers(pcm);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static struct snd_soc_platform_driver cygnus_soc_platform = {
+	.ops		= &cygnus_pcm_ops,
+	.pcm_new	= cygnus_dma_new,
+	.pcm_free	= cygnus_dma_free_dma_buffers,
+};
+
+int cygnus_soc_platform_register(struct device *dev,
+				 struct cygnus_audio *cygaud)
+{
+	int rc = 0;
+
+	dev_dbg(dev, "%s Enter\n", __func__);
+
+	rc = devm_request_irq(dev, cygaud->irq_num, cygnus_dma_irq,
+				IRQF_SHARED, "cygnus-audio", cygaud);
+	if (rc) {
+		dev_err(dev, "%s request_irq error %d\n", __func__, rc);
+		return rc;
+	}
+
+	rc = snd_soc_register_platform(dev, &cygnus_soc_platform);
+	if (rc) {
+		dev_err(dev, "%s failed\n", __func__);
+		return rc;
+	}
+
+	return 0;
+}
+
+int cygnus_soc_platform_unregister(struct device *dev)
+{
+	snd_soc_unregister_platform(dev);
+
+	return 0;
+}
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("Cygnus ASoC PCM module");