Patchwork [U-Boot,1/9,V2] SOUND: Add I2S driver

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Submitter Rajeshwari Birje
Date Aug. 22, 2012, 6:44 a.m.
Message ID <1345617865-14199-2-git-send-email-rajeshwari.s@samsung.com>
Download mbox | patch
Permalink /patch/179237/
State Superseded
Delegated to: Minkyu Kang
Headers show

Comments

Rajeshwari Birje - Aug. 22, 2012, 6:44 a.m.
This patch adds driver for I2S interface specific to samsung.

Signed-off-by: R. Chandrasekar <rcsekar@samsung.com>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
---
Changes in V2:
- renamed i2s.c to samsung-i2s.c.
 Makefile                    |    1 +
 drivers/sound/Makefile      |   47 ++++++
 drivers/sound/samsung-i2s.c |  358 +++++++++++++++++++++++++++++++++++++++++++
 drivers/sound/sound.c       |  220 ++++++++++++++++++++++++++
 include/i2s.h               |  127 +++++++++++++++
 include/sound.h             |   62 ++++++++
 6 files changed, 815 insertions(+), 0 deletions(-)
 create mode 100644 drivers/sound/Makefile
 create mode 100644 drivers/sound/samsung-i2s.c
 create mode 100644 drivers/sound/sound.c
 create mode 100644 include/i2s.h
 create mode 100644 include/sound.h
Simon Glass - Oct. 16, 2012, 6:18 p.m.
Hi,

On Tue, Aug 21, 2012 at 11:44 PM, Rajeshwari Shinde
<rajeshwari.s@samsung.com> wrote:
> This patch adds driver for I2S interface specific to samsung.
>
> Signed-off-by: R. Chandrasekar <rcsekar@samsung.com>
> Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
> ---
> Changes in V2:
> - renamed i2s.c to samsung-i2s.c.
>  Makefile                    |    1 +
>  drivers/sound/Makefile      |   47 ++++++
>  drivers/sound/samsung-i2s.c |  358 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/sound/sound.c       |  220 ++++++++++++++++++++++++++
>  include/i2s.h               |  127 +++++++++++++++
>  include/sound.h             |   62 ++++++++
>  6 files changed, 815 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/sound/Makefile
>  create mode 100644 drivers/sound/samsung-i2s.c
>  create mode 100644 drivers/sound/sound.c
>  create mode 100644 include/i2s.h
>  create mode 100644 include/sound.h
>

Rather than have a big table for the sound, can we calculate it, as in
the Chromium tree?

Regards,
Simon


> +       while (freq--) {
> +               i = ARRAY_SIZE(sine_table_400);
> +
> +               for (i = 0; i < ARRAY_SIZE(sine_table_400); i++) {
> +                       *data++ = sine_table_400[i];
> +                       *data++ = sine_table_400[i];
> +               }
> +       }
> +}
> +

Patch

diff --git a/Makefile b/Makefile
index f6471e2..fc929e8e 100644
--- a/Makefile
+++ b/Makefile
@@ -288,6 +288,7 @@  LIBS += arch/powerpc/cpu/mpc8xxx/lib8xxx.o
 endif
 LIBS += drivers/rtc/librtc.o
 LIBS += drivers/serial/libserial.o
+LIBS += drivers/sound/libsound.o
 ifeq ($(CONFIG_GENERIC_LPC_TPM),y)
 LIBS += drivers/tpm/libtpm.o
 endif
diff --git a/drivers/sound/Makefile b/drivers/sound/Makefile
new file mode 100644
index 0000000..18ad2c9
--- /dev/null
+++ b/drivers/sound/Makefile
@@ -0,0 +1,47 @@ 
+#
+# Copyright (C) 2012 Samsung Electronics
+# R. Chandrasekar <rcsekar@samsung.com>
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# 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; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	:= $(obj)libsound.o
+
+COBJS-$(CONFIG_SOUND)	+= sound.o
+COBJS-$(CONFIG_I2S)	+= samsung-i2s.o
+
+COBJS	:= $(COBJS-y)
+SRCS	:= $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#
diff --git a/drivers/sound/samsung-i2s.c b/drivers/sound/samsung-i2s.c
new file mode 100644
index 0000000..9485980
--- /dev/null
+++ b/drivers/sound/samsung-i2s.c
@@ -0,0 +1,358 @@ 
+/*
+ * Copyright (C) 2012 Samsung Electronics
+ * R. Chandrasekar <rcsekar@samsung.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <asm/arch/clk.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/i2s-regs.h>
+#include <asm/io.h>
+#include <common.h>
+#include <sound.h>
+#include <i2s.h>
+
+#define FIC_TX2COUNT(x)		(((x) >>  24) & 0xf)
+#define FIC_TX1COUNT(x)		(((x) >>  16) & 0xf)
+#define FIC_TXCOUNT(x)		(((x) >>  8) & 0xf)
+#define FIC_RXCOUNT(x)		(((x) >>  0) & 0xf)
+#define FICS_TXCOUNT(x)		(((x) >>  8) & 0x7f)
+
+#define TIMEOUT_I2S_TX		100	/* i2s transfer timeout */
+
+/*
+ * Sets the frame size for I2S LR clock
+ *
+ * @param i2s_reg	i2s regiter address
+ * @param rfs		Frame Size
+ */
+static void i2s_set_lr_framesize(struct i2s_reg *i2s_reg, unsigned int rfs)
+{
+	unsigned int mod = readl(&i2s_reg->mod);
+
+	mod &= ~MOD_RCLK_MASK;
+
+	switch (rfs) {
+	case 768:
+		mod |= MOD_RCLK_768FS;
+		break;
+	case 512:
+		mod |= MOD_RCLK_512FS;
+		break;
+	case 384:
+		mod |= MOD_RCLK_384FS;
+		break;
+	default:
+		mod |= MOD_RCLK_256FS;
+		break;
+	}
+
+	writel(mod, &i2s_reg->mod);
+}
+
+/*
+ * Sets the i2s transfer control
+ *
+ * @param i2s_reg	i2s regiter address
+ * @param on		1 enable tx , 0 disable tx transfer
+ */
+static void i2s_txctrl(struct i2s_reg *i2s_reg, int on)
+{
+	unsigned int con = readl(&i2s_reg->con);
+	unsigned int mod = readl(&i2s_reg->mod) & ~MOD_MASK;
+
+	if (on) {
+		con |= CON_ACTIVE;
+		con &= ~CON_TXCH_PAUSE;
+
+	} else {
+
+		con |=  CON_TXCH_PAUSE;
+		con &= ~CON_ACTIVE;
+	}
+
+	writel(mod, &i2s_reg->mod);
+	writel(con, &i2s_reg->con);
+}
+
+/*
+ * set the bit clock frame size (in multiples of LRCLK)
+ *
+ * @param i2s_reg	i2s regiter address
+ * @param bfs		bit Frame Size
+ */
+static void i2s_set_bitclk_framesize(struct i2s_reg *i2s_reg, unsigned bfs)
+{
+	unsigned int mod = readl(&i2s_reg->mod);
+
+	mod &= ~MOD_BCLK_MASK;
+
+	switch (bfs) {
+	case 48:
+		mod |= MOD_BCLK_48FS;
+		break;
+	case 32:
+		mod |= MOD_BCLK_32FS;
+		break;
+	case 24:
+		mod |= MOD_BCLK_24FS;
+		break;
+	case 16:
+		mod |= MOD_BCLK_16FS;
+		break;
+	default:
+		return;
+	}
+	writel(mod, &i2s_reg->mod);
+}
+
+/*
+ * flushes the i2stx fifo
+ *
+ * @param i2s_reg	i2s regiter address
+ * @param flush		Tx fifo flush command (0x00 - do not flush
+ *				0x80 - flush tx fifo)
+ */
+void i2s_fifo(struct i2s_reg *i2s_reg, unsigned int flush)
+{
+	/* Flush the FIFO */
+	setbits_le32(&i2s_reg->fic, flush);
+	clrbits_le32(&i2s_reg->fic, flush);
+}
+
+/*
+ * Set System Clock direction
+ *
+ * @param i2s_reg	i2s regiter address
+ * @param dir		Clock direction
+ *
+ * @return		int value 0 for success, -1 in case of error
+ */
+int i2s_set_sysclk_dir(struct i2s_reg *i2s_reg, int dir)
+{
+	unsigned int mod = readl(&i2s_reg->mod);
+
+	if (dir == SND_SOC_CLOCK_IN)
+		mod |= MOD_CDCLKCON;
+	else
+		mod &= ~MOD_CDCLKCON;
+
+	writel(mod, &i2s_reg->mod);
+
+	return 0;
+}
+
+/*
+ * Sets I2S Clcok format
+ *
+ * @param fmt		i2s clock properties
+ * @param i2s_reg	i2s regiter address
+ *
+ * @return		int value 0 for success, -1 in case of error
+ */
+int i2s_set_fmt(struct i2s_reg *i2s_reg, unsigned int fmt)
+{
+	unsigned int mod = readl(&i2s_reg->mod);
+	unsigned int tmp = 0;
+	unsigned int ret = 0;
+
+	/* Format is priority */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_RIGHT_J:
+		tmp |= MOD_LR_RLOW;
+		tmp |= MOD_SDF_MSB;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		tmp |= MOD_LR_RLOW;
+		tmp |= MOD_SDF_LSB;
+		break;
+	case SND_SOC_DAIFMT_I2S:
+		tmp |= MOD_SDF_IIS;
+		break;
+	default:
+		debug("%s: Invalid format priority [0x%x]\n", __func__,
+			(fmt & SND_SOC_DAIFMT_FORMAT_MASK));
+		return -1;
+	}
+
+	/*
+	 * INV flag is relative to the FORMAT flag - if set it simply
+	 * flips the polarity specified by the Standard
+	 */
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		if (tmp & MOD_LR_RLOW)
+			tmp &= ~MOD_LR_RLOW;
+		else
+			tmp |= MOD_LR_RLOW;
+		break;
+	default:
+		debug("%s: Invalid clock ploarity input [0x%x]\n", __func__,
+			(fmt & SND_SOC_DAIFMT_INV_MASK));
+		return -1;
+	}
+
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBS_CFS:
+		tmp |= MOD_SLAVE;
+		break;
+	case SND_SOC_DAIFMT_CBM_CFM:
+		/* Set default source clock in Master mode */
+		ret = i2s_set_sysclk_dir(i2s_reg, SND_SOC_CLOCK_OUT);
+		if (ret != 0) {
+			debug("%s:set i2s clock direction failed\n", __func__);
+			return -1;
+		}
+		break;
+	default:
+		debug("%s: Invalid master selection [0x%x]\n", __func__,
+			(fmt & SND_SOC_DAIFMT_MASTER_MASK));
+		return -1;
+	}
+
+	mod &= ~(MOD_SDF_MASK | MOD_LR_RLOW | MOD_SLAVE);
+	mod |= tmp;
+	writel(mod, &i2s_reg->mod);
+
+	return 0;
+}
+
+/*
+ * Sets the sample width in bits
+ *
+ * @param blc		samplewidth (size of sample in bits)
+ * @param i2s_reg	i2s regiter address
+ *
+ * @return		int value 0 for success, -1 in case of error
+ */
+int i2s_set_samplesize(struct i2s_reg *i2s_reg, unsigned int blc)
+{
+	unsigned int mod = readl(&i2s_reg->mod);
+
+	mod &= ~MOD_BLCP_MASK;
+	mod &= ~MOD_BLC_MASK;
+
+	switch (blc) {
+	case 8:
+		mod |= MOD_BLCP_8BIT;
+		mod |= MOD_BLC_8BIT;
+		break;
+	case 16:
+		mod |= MOD_BLCP_16BIT;
+		mod |= MOD_BLC_16BIT;
+		break;
+
+	case 24:
+		mod |= MOD_BLCP_24BIT;
+		mod |= MOD_BLC_24BIT;
+		break;
+	default:
+		debug("%s: Invalid sample size input [0x%x]\n",
+			__func__, blc);
+		return -1;
+	}
+	writel(mod, &i2s_reg->mod);
+
+	return 0;
+}
+
+int i2s_transfer_tx_data(struct i2stx_info *pi2s_tx, unsigned int *data,
+				unsigned long data_size)
+{
+	int i;
+	int start;
+	struct i2s_reg *i2s_reg =
+				(struct i2s_reg *)pi2s_tx->base_address;
+
+	if (data_size < FIFO_LENGTH) {
+		debug("%s : Invalid data size\n", __func__);
+		return -1; /* invalid pcm data size */
+	}
+
+	/* fill the tx buffer before stating the tx transmit */
+	for (i = 0; i < FIFO_LENGTH; i++)
+		writel(*data++, &i2s_reg->txd);
+
+	data_size -= FIFO_LENGTH;
+	i2s_txctrl(i2s_reg, I2S_TX_ON);
+
+	while (data_size > 0) {
+		start = get_timer(0);
+		if (!(CON_TXFIFO_FULL & (readl(&i2s_reg->con)))) {
+			writel(*data++, &i2s_reg->txd);
+			data_size--;
+		} else {
+			if (get_timer(start) > TIMEOUT_I2S_TX) {
+				i2s_txctrl(i2s_reg, I2S_TX_OFF);
+				debug("%s: I2S Transfer Timeout\n", __func__);
+				return -1;
+			}
+		}
+	}
+	i2s_txctrl(i2s_reg, I2S_TX_OFF);
+
+	return 0;
+}
+
+int i2s_tx_init(struct i2stx_info *pi2s_tx)
+{
+	int ret;
+	struct i2s_reg *i2s_reg =
+				(struct i2s_reg *)pi2s_tx->base_address;
+
+	/* Initialize GPIO for I2s */
+	exynos_pinmux_config(PERIPH_ID_I2S1, 0);
+
+	/* Set EPLL Clock */
+	ret = clock_epll_set_rate(pi2s_tx->audio_pll_clk);
+	if (ret != 0) {
+		debug("%s: epll clock set rate falied\n", __func__);
+		return -1;
+	}
+
+	/* Select Clk Source for Audio1 */
+	clock_select_i2s_clk_source();
+
+	/* Set Prescaler to get MCLK */
+	clock_set_i2s_clk_prescaler(pi2s_tx->audio_pll_clk,
+				(pi2s_tx->samplingrate * (pi2s_tx->rfs)));
+
+	/* Configure I2s format */
+	ret = i2s_set_fmt(i2s_reg, (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
+				SND_SOC_DAIFMT_CBM_CFM));
+	if (ret == 0) {
+		i2s_set_lr_framesize(i2s_reg, pi2s_tx->rfs);
+		ret = i2s_set_samplesize(i2s_reg, pi2s_tx->bitspersample);
+		if (ret != 0) {
+			debug("%s:set sample rate failed\n", __func__);
+			return -1;
+		}
+
+		i2s_set_bitclk_framesize(i2s_reg, pi2s_tx->bfs);
+		/* disable i2s transfer flag and flush the fifo */
+		i2s_txctrl(i2s_reg, I2S_TX_OFF);
+		i2s_fifo(i2s_reg, FIC_TXFLUSH);
+	} else
+		debug("%s: failed\n", __func__);
+
+	return ret;
+}
diff --git a/drivers/sound/sound.c b/drivers/sound/sound.c
new file mode 100644
index 0000000..84a7281
--- /dev/null
+++ b/drivers/sound/sound.c
@@ -0,0 +1,220 @@ 
+/*
+ * Copyright (C) 2012 Samsung Electronics
+ * R. Chandrasekar <rcsekar@samsung.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <malloc.h>
+#include <common.h>
+#include <asm/io.h>
+#include <i2c.h>
+#include <i2s.h>
+#include <sound.h>
+#include "wm8994.h"
+#include <asm/arch/sound.h>
+
+/* defines */
+#define SOUND_400_HZ 400
+#define SOUND_BITS_IN_BYTE 8
+
+/* pcm values for 400hz 48k sampling rate from 1 cycle */
+unsigned short sine_table_400[120] = {
+	0, 1714, 3425, 5125, 6812, 8480, 10125, 11742, 13327, 14875, 16383,
+	17846, 19259, 20620, 21925, 23169, 24350, 25464, 26509, 27480, 28377,
+	29195, 29934, 30590, 31163, 31650, 32050, 32363, 32587, 32722, 32767,
+	32722, 32587, 32363, 32050, 31650, 31163, 30590, 29934, 29195, 28377,
+	27480, 26509, 25464, 24350, 23169, 21925, 20620, 19259, 17846, 16383,
+	14875, 13327, 11742, 10125, 8480, 6812, 5125, 3425, 1714, 0, -1714,
+	-3425, -5125, -6812, -8480, -10125, -11742, -13327, -14875, -16383,
+	-17846, -19259, -20620, -21925, -23169, -24350, -25464, -26509,
+	-27480, -28377, -29195, -29934, -30590, -31163, -31650, -32050,
+	-32363, -32587, -32722, -32767, -32722, -32587, -32363, -32050,
+	-31650, -31163, -30590, -29934, -29195, -28377, -27480, -26509,
+	-25464, -24350, -23169, -21925, -20620, -19259, -17846, -16383,
+	-14875, -13327, -11742, -10125, -8480, -6812, -5125, -3425, -1714
+};
+
+/* Globals */
+struct i2stx_info g_i2stx_pri;
+struct sound_codec_info g_codec_info;
+
+/*
+ * get_sound_fdt_values gets fdt values for i2s parameters
+ *
+ * @param i2stx_info	i2s transmitter transfer param structure
+ * @param blob		FDT blob
+ */
+static void get_sound_i2s_values(struct i2stx_info *i2s)
+{
+	i2s->base_address = samsung_get_base_i2s();
+	i2s->audio_pll_clk = I2S_PLL_CLK;
+	i2s->samplingrate = I2S_SAMPLING_RATE;
+	i2s->bitspersample = I2S_BITS_PER_SAMPLE;
+	i2s->channels = I2S_CHANNELS;
+	i2s->rfs = I2S_RFS;
+	i2s->bfs = I2S_BFS;
+}
+
+/*
+ * Gets fdt values for wm8994 config parameters
+ *
+ * @param pcodec_info	codec information structure
+ * @param blob		FDT blob
+ * @return		int value, 0 for success
+ */
+static int get_sound_wm8994_values(struct sound_codec_info *pcodec_info)
+{
+	int error = 0;
+
+	switch (AUDIO_COMPAT) {
+	case AUDIO_COMPAT_SPI:
+		debug("%s: Support not added for SPI interface\n", __func__);
+		return -1;
+		break;
+	case AUDIO_COMPAT_I2C:
+		pcodec_info->i2c_bus = AUDIO_I2C_BUS;
+		pcodec_info->i2c_dev_addr = AUDIO_I2C_REG;
+		debug("i2c dev addr = %d\n", pcodec_info->i2c_dev_addr);
+		break;
+	default:
+		debug("%s: Unknown compat id %d\n", __func__, AUDIO_COMPAT);
+		return -1;
+	}
+
+	if (error == -1) {
+		debug("fail to get wm8994 codec node properties\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Gets fdt values for codec config parameters
+ *
+ * @param pcodec_info	codec information structure
+ * @param blob		FDT blob
+ * @return		int value, 0 for success
+ */
+static int get_sound_codec_values(struct sound_codec_info *pcodec_info)
+{
+	int error = 0;
+	const char *codectype;
+
+	codectype =  AUDIO_CODEC;
+
+	if (!strcmp(codectype, "wm8994")) {
+		pcodec_info->codec_type = CODEC_WM_8994;
+		error = get_sound_wm8994_values(pcodec_info);
+	} else
+		error = -1;
+
+	if (error == -1) {
+		debug("fail to get sound codec node properties\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+int sound_init(void)
+{
+	int ret;
+	struct i2stx_info *pi2s_tx = &g_i2stx_pri;
+	struct sound_codec_info *pcodec_info = &g_codec_info;
+
+	/* Get the I2S Values */
+	get_sound_i2s_values(pi2s_tx);
+
+	/* Get the codec Values */
+	if (get_sound_codec_values(pcodec_info) < 0)
+		return -1;
+
+	ret = i2s_tx_init(pi2s_tx);
+	if (ret) {
+		debug("%s: Failed to init i2c transmit: ret=%d\n", __func__,
+		      ret);
+		return ret;
+	}
+
+	/* Check the codec type and initialise the same */
+	if (pcodec_info->codec_type == CODEC_WM_8994) {
+		ret = wm8994_init(pcodec_info, WM8994_AIF2,
+			pi2s_tx->samplingrate,
+			(pi2s_tx->samplingrate * (pi2s_tx->rfs)),
+			pi2s_tx->bitspersample, pi2s_tx->channels);
+	} else {
+		debug("%s: Unknown code type %d\n", __func__,
+		      pcodec_info->codec_type);
+		return -1;
+	}
+	if (ret) {
+		debug("%s: Codec init failed\n", __func__);
+		return -1;
+	}
+
+	return ret;
+}
+
+/*
+ * Generates 400hz sine wave data for 1sec
+ *
+ * @param samplingrate	samplinng rate of the sinewave need to be generated
+ * @param data		data buffer pointer
+ */
+static void sound_prepare_sinewave_400hz_buffer(unsigned short *data)
+{
+	int freq = SOUND_400_HZ;
+	int i;
+
+	while (freq--) {
+		i = ARRAY_SIZE(sine_table_400);
+
+		for (i = 0; i < ARRAY_SIZE(sine_table_400); i++) {
+			*data++ = sine_table_400[i];
+			*data++ = sine_table_400[i];
+		}
+	}
+}
+
+int sound_play(void)
+{
+	unsigned int *data;
+	unsigned long data_size;
+	unsigned int ret;
+
+	/* Sine wave Buffer length computation */
+	data_size = g_i2stx_pri.samplingrate * g_i2stx_pri.channels;
+	data_size *= (g_i2stx_pri.bitspersample / SOUND_BITS_IN_BYTE);
+	data = malloc(data_size);
+
+	if (data == NULL) {
+		debug("%s: malloc failed\n", __func__);
+		return -1;
+	}
+
+	sound_prepare_sinewave_400hz_buffer((unsigned short *)data);
+
+	ret = i2s_transfer_tx_data(&g_i2stx_pri, data,
+				   (data_size / sizeof(int)));
+	free(data);
+
+	return ret;
+}
diff --git a/include/i2s.h b/include/i2s.h
new file mode 100644
index 0000000..f1b642e
--- /dev/null
+++ b/include/i2s.h
@@ -0,0 +1,127 @@ 
+/*
+ * Copyright (C) 2012 Samsung Electronics
+ * R. Chandrasekar <rcsekar@samsung.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __I2S_H__
+#define __I2S_H__
+
+/*
+ * DAI hardware audio formats.
+ *
+ * Describes the physical PCM data formating and clocking. Add new formats
+ * to the end.
+ */
+#define SND_SOC_DAIFMT_I2S		1 /* I2S mode */
+#define SND_SOC_DAIFMT_RIGHT_J		2 /* Right Justified mode */
+#define SND_SOC_DAIFMT_LEFT_J		3 /* Left Justified mode */
+#define SND_SOC_DAIFMT_DSP_A		4 /* L data MSB after FRM LRC */
+#define SND_SOC_DAIFMT_DSP_B		5 /* L data MSB during FRM LRC */
+#define SND_SOC_DAIFMT_AC97		6 /* AC97 */
+#define SND_SOC_DAIFMT_PDM		7 /* Pulse density modulation */
+
+/* left and right justified also known as MSB and LSB respectively */
+#define SND_SOC_DAIFMT_MSB		SND_SOC_DAIFMT_LEFT_J
+#define SND_SOC_DAIFMT_LSB		SND_SOC_DAIFMT_RIGHT_J
+
+/*
+ * DAI hardware signal inversions.
+ *
+ * Specifies whether the DAI can also support inverted clocks for the specified
+ * format.
+ */
+#define SND_SOC_DAIFMT_NB_NF	(1 << 8) /* normal bit clock + frame */
+#define SND_SOC_DAIFMT_NB_IF	(2 << 8) /* normal BCLK + inv FRM */
+#define SND_SOC_DAIFMT_IB_NF	(3 << 8) /* invert BCLK + nor FRM */
+#define SND_SOC_DAIFMT_IB_IF	(4 << 8) /* invert BCLK + FRM */
+
+/*
+ * DAI hardware clock masters.
+ *
+ * This is wrt the codec, the inverse is true for the interface
+ * i.e. if the codec is clk and FRM master then the interface is
+ * clk and frame slave.
+ */
+#define SND_SOC_DAIFMT_CBM_CFM	(1 << 12) /* codec clk & FRM master */
+#define SND_SOC_DAIFMT_CBS_CFM	(2 << 12) /* codec clk slave & FRM master */
+#define SND_SOC_DAIFMT_CBM_CFS	(3 << 12) /* codec clk master & frame slave */
+#define SND_SOC_DAIFMT_CBS_CFS	(4 << 12) /* codec clk & FRM slave */
+
+#define SND_SOC_DAIFMT_FORMAT_MASK	0x000f
+#define SND_SOC_DAIFMT_CLOCK_MASK	0x00f0
+#define SND_SOC_DAIFMT_INV_MASK		0x0f00
+#define SND_SOC_DAIFMT_MASTER_MASK	0xf000
+
+/*
+ * Master Clock Directions
+ */
+#define SND_SOC_CLOCK_IN		0
+#define SND_SOC_CLOCK_OUT		1
+
+/* I2S Tx Control */
+#define I2S_TX_ON	1
+#define I2S_TX_OFF	0
+
+#define FIFO_LENGTH	64
+
+/* I2s Registers */
+struct i2s_reg {
+	unsigned int	con;		/* base + 0 , Control register */
+	unsigned int	mod;		/* Mode register */
+	unsigned int	fic;		/* FIFO control register */
+	unsigned int	psr;		/* Reserved */
+	unsigned int	txd;		/* Transmit data register */
+	unsigned int	rxd;		/* Receive Data Register */
+};
+
+/* This structure stores the i2s related information */
+struct i2stx_info {
+	unsigned int rfs;		/* LR clock frame size */
+	unsigned int bfs;		/* Bit slock frame size */
+	unsigned int audio_pll_clk;	/* Audio pll frequency in Hz */
+	unsigned int samplingrate;	/* sampling rate */
+	unsigned int bitspersample;	/* bits per sample */
+	unsigned int channels;		/* audio channels */
+	unsigned int base_address;	/* I2S Register Base */
+};
+
+/*
+ * Sends the given data through i2s tx
+ *
+ * @param pi2s_tx	pointer of i2s transmitter parameter structure.
+ * @param *data		address of the data buffer
+ * @param data_size	array size of the int buffer (total size / size of int)
+ *
+ * @return		int value 0 for success, -1 in case of error
+ */
+int i2s_transfer_tx_data(struct i2stx_info *pi2s_tx, unsigned *data,
+				unsigned long data_size);
+
+/*
+ * Initialise i2s transmiter
+ *
+ * @param pi2s_tx	pointer of i2s transmitter parameter structure.
+ *
+ * @return		int value 0 for success, -1 in case of error
+ */
+int i2s_tx_init(struct i2stx_info *pi2s_tx);
+
+#endif /* __I2S_H__ */
diff --git a/include/sound.h b/include/sound.h
new file mode 100644
index 0000000..1d29ded
--- /dev/null
+++ b/include/sound.h
@@ -0,0 +1,62 @@ 
+/*
+ * Copyright (C) 2012 Samsung Electronics
+ * R. Chandrasekar < rcsekar@samsung.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __SOUND_H__
+#define __SOUND_H__
+
+/* sound codec enum */
+enum en_sound_codec {
+	CODEC_WM_8994,
+	CODEC_WM_8995,
+	CODEC_MAX
+};
+
+/* sound codec enum */
+enum sound_compat {
+	AUDIO_COMPAT_SPI,
+	AUDIO_COMPAT_I2C,
+};
+
+/* Codec information structure to store the info from device tree */
+struct sound_codec_info {
+	int i2c_bus;
+	int i2c_dev_addr;
+	enum en_sound_codec codec_type;
+};
+
+/*
+ * Initialises audio sub system
+ *
+ * @return	int value 0 for success, -1 for error
+ */
+int sound_init(void);
+
+/*
+ * plays the pcm data buffer in pcm_data.h through i2s1 to make the
+ * sine wave sound
+ *
+ * @return	int 0 for success, -1 for error
+ */
+int sound_play(void);
+
+#endif  /* __SOUND__H__ */