OMAP: mcbsp: Move core driver under sound/soc/omap

In order to consolidate the McBSP driver move it out from
arch/arm/plat-omap directory under sound/soc/omap/

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Liam Girdwood <lrg@ti.com>

1 files changed, 1364 insertions, 0 deletions

diff --git a/sound/soc/omap/mcbsp.c b/sound/soc/omap/mcbsp.c
new file mode 100644
index 000000000000..36d83b0c9f02
--- /dev/null
+++ b/sound/soc/omap/mcbsp.c
@@ -0,0 +1,1364 @@
+/*
+ * sound/soc/omap/mcbsp.c
+ *
+ * Copyright (C) 2004 Nokia Corporation
+ * Author: Samuel Ortiz <samuel.ortiz@nokia.com>
+ *
+ * Contact: Jarkko Nikula <jarkko.nikula@bitmer.com>
+ *          Peter Ujfalusi <peter.ujfalusi@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Multichannel mode not supported.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include <plat/mcbsp.h>
+#include <linux/pm_runtime.h>
+
+struct omap_mcbsp **mcbsp_ptr;
+int omap_mcbsp_count;
+
+#define omap_mcbsp_check_valid_id(id)	(id < omap_mcbsp_count)
+#define id_to_mcbsp_ptr(id)		mcbsp_ptr[id];
+
+static void omap_mcbsp_write(struct omap_mcbsp *mcbsp, u16 reg, u32 val)
+{
+	void __iomem *addr = mcbsp->io_base + reg * mcbsp->pdata->reg_step;
+
+	if (mcbsp->pdata->reg_size == 2) {
+		((u16 *)mcbsp->reg_cache)[reg] = (u16)val;
+		__raw_writew((u16)val, addr);
+	} else {
+		((u32 *)mcbsp->reg_cache)[reg] = val;
+		__raw_writel(val, addr);
+	}
+}
+
+static int omap_mcbsp_read(struct omap_mcbsp *mcbsp, u16 reg, bool from_cache)
+{
+	void __iomem *addr = mcbsp->io_base + reg * mcbsp->pdata->reg_step;
+
+	if (mcbsp->pdata->reg_size == 2) {
+		return !from_cache ? __raw_readw(addr) :
+				     ((u16 *)mcbsp->reg_cache)[reg];
+	} else {
+		return !from_cache ? __raw_readl(addr) :
+				     ((u32 *)mcbsp->reg_cache)[reg];
+	}
+}
+
+static void omap_mcbsp_st_write(struct omap_mcbsp *mcbsp, u16 reg, u32 val)
+{
+	__raw_writel(val, mcbsp->st_data->io_base_st + reg);
+}
+
+static int omap_mcbsp_st_read(struct omap_mcbsp *mcbsp, u16 reg)
+{
+	return __raw_readl(mcbsp->st_data->io_base_st + reg);
+}
+
+#define MCBSP_READ(mcbsp, reg) \
+		omap_mcbsp_read(mcbsp, OMAP_MCBSP_REG_##reg, 0)
+#define MCBSP_WRITE(mcbsp, reg, val) \
+		omap_mcbsp_write(mcbsp, OMAP_MCBSP_REG_##reg, val)
+#define MCBSP_READ_CACHE(mcbsp, reg) \
+		omap_mcbsp_read(mcbsp, OMAP_MCBSP_REG_##reg, 1)
+
+#define MCBSP_ST_READ(mcbsp, reg) \
+			omap_mcbsp_st_read(mcbsp, OMAP_ST_REG_##reg)
+#define MCBSP_ST_WRITE(mcbsp, reg, val) \
+			omap_mcbsp_st_write(mcbsp, OMAP_ST_REG_##reg, val)
+
+static void omap_mcbsp_dump_reg(u8 id)
+{
+	struct omap_mcbsp *mcbsp = id_to_mcbsp_ptr(id);
+
+	dev_dbg(mcbsp->dev, "**** McBSP%d regs ****\n", mcbsp->id);
+	dev_dbg(mcbsp->dev, "DRR2:  0x%04x\n",
+			MCBSP_READ(mcbsp, DRR2));
+	dev_dbg(mcbsp->dev, "DRR1:  0x%04x\n",
+			MCBSP_READ(mcbsp, DRR1));
+	dev_dbg(mcbsp->dev, "DXR2:  0x%04x\n",
+			MCBSP_READ(mcbsp, DXR2));
+	dev_dbg(mcbsp->dev, "DXR1:  0x%04x\n",
+			MCBSP_READ(mcbsp, DXR1));
+	dev_dbg(mcbsp->dev, "SPCR2: 0x%04x\n",
+			MCBSP_READ(mcbsp, SPCR2));
+	dev_dbg(mcbsp->dev, "SPCR1: 0x%04x\n",
+			MCBSP_READ(mcbsp, SPCR1));
+	dev_dbg(mcbsp->dev, "RCR2:  0x%04x\n",
+			MCBSP_READ(mcbsp, RCR2));
+	dev_dbg(mcbsp->dev, "RCR1:  0x%04x\n",
+			MCBSP_READ(mcbsp, RCR1));
+	dev_dbg(mcbsp->dev, "XCR2:  0x%04x\n",
+			MCBSP_READ(mcbsp, XCR2));
+	dev_dbg(mcbsp->dev, "XCR1:  0x%04x\n",
+			MCBSP_READ(mcbsp, XCR1));
+	dev_dbg(mcbsp->dev, "SRGR2: 0x%04x\n",
+			MCBSP_READ(mcbsp, SRGR2));
+	dev_dbg(mcbsp->dev, "SRGR1: 0x%04x\n",
+			MCBSP_READ(mcbsp, SRGR1));
+	dev_dbg(mcbsp->dev, "PCR0:  0x%04x\n",
+			MCBSP_READ(mcbsp, PCR0));
+	dev_dbg(mcbsp->dev, "***********************\n");
+}
+
+static irqreturn_t omap_mcbsp_tx_irq_handler(int irq, void *dev_id)
+{
+	struct omap_mcbsp *mcbsp_tx = dev_id;
+	u16 irqst_spcr2;
+
+	irqst_spcr2 = MCBSP_READ(mcbsp_tx, SPCR2);
+	dev_dbg(mcbsp_tx->dev, "TX IRQ callback : 0x%x\n", irqst_spcr2);
+
+	if (irqst_spcr2 & XSYNC_ERR) {
+		dev_err(mcbsp_tx->dev, "TX Frame Sync Error! : 0x%x\n",
+			irqst_spcr2);
+		/* Writing zero to XSYNC_ERR clears the IRQ */
+		MCBSP_WRITE(mcbsp_tx, SPCR2, MCBSP_READ_CACHE(mcbsp_tx, SPCR2));
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t omap_mcbsp_rx_irq_handler(int irq, void *dev_id)
+{
+	struct omap_mcbsp *mcbsp_rx = dev_id;
+	u16 irqst_spcr1;
+
+	irqst_spcr1 = MCBSP_READ(mcbsp_rx, SPCR1);
+	dev_dbg(mcbsp_rx->dev, "RX IRQ callback : 0x%x\n", irqst_spcr1);
+
+	if (irqst_spcr1 & RSYNC_ERR) {
+		dev_err(mcbsp_rx->dev, "RX Frame Sync Error! : 0x%x\n",
+			irqst_spcr1);
+		/* Writing zero to RSYNC_ERR clears the IRQ */
+		MCBSP_WRITE(mcbsp_rx, SPCR1, MCBSP_READ_CACHE(mcbsp_rx, SPCR1));
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * omap_mcbsp_config simply write a config to the
+ * appropriate McBSP.
+ * You either call this function or set the McBSP registers
+ * by yourself before calling omap_mcbsp_start().
+ */
+void omap_mcbsp_config(unsigned int id, const struct omap_mcbsp_reg_cfg *config)
+{
+	struct omap_mcbsp *mcbsp;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	dev_dbg(mcbsp->dev, "Configuring McBSP%d  phys_base: 0x%08lx\n",
+			mcbsp->id, mcbsp->phys_base);
+
+	/* We write the given config */
+	MCBSP_WRITE(mcbsp, SPCR2, config->spcr2);
+	MCBSP_WRITE(mcbsp, SPCR1, config->spcr1);
+	MCBSP_WRITE(mcbsp, RCR2, config->rcr2);
+	MCBSP_WRITE(mcbsp, RCR1, config->rcr1);
+	MCBSP_WRITE(mcbsp, XCR2, config->xcr2);
+	MCBSP_WRITE(mcbsp, XCR1, config->xcr1);
+	MCBSP_WRITE(mcbsp, SRGR2, config->srgr2);
+	MCBSP_WRITE(mcbsp, SRGR1, config->srgr1);
+	MCBSP_WRITE(mcbsp, MCR2, config->mcr2);
+	MCBSP_WRITE(mcbsp, MCR1, config->mcr1);
+	MCBSP_WRITE(mcbsp, PCR0, config->pcr0);
+	if (mcbsp->pdata->has_ccr) {
+		MCBSP_WRITE(mcbsp, XCCR, config->xccr);
+		MCBSP_WRITE(mcbsp, RCCR, config->rccr);
+	}
+}
+EXPORT_SYMBOL(omap_mcbsp_config);
+
+/**
+ * omap_mcbsp_dma_params - returns the dma channel number
+ * @id - mcbsp id
+ * @stream - indicates the direction of data flow (rx or tx)
+ *
+ * Returns the dma channel number for the rx channel or tx channel
+ * based on the value of @stream for the requested mcbsp given by @id
+ */
+int omap_mcbsp_dma_ch_params(unsigned int id, unsigned int stream)
+{
+	struct omap_mcbsp *mcbsp;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	if (stream)
+		return mcbsp->dma_rx_sync;
+	else
+		return mcbsp->dma_tx_sync;
+}
+EXPORT_SYMBOL(omap_mcbsp_dma_ch_params);
+
+/**
+ * omap_mcbsp_dma_reg_params - returns the address of mcbsp data register
+ * @id - mcbsp id
+ * @stream - indicates the direction of data flow (rx or tx)
+ *
+ * Returns the address of mcbsp data transmit register or data receive register
+ * to be used by DMA for transferring/receiving data based on the value of
+ * @stream for the requested mcbsp given by @id
+ */
+int omap_mcbsp_dma_reg_params(unsigned int id, unsigned int stream)
+{
+	struct omap_mcbsp *mcbsp;
+	int data_reg;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	if (mcbsp->pdata->reg_size == 2) {
+		if (stream)
+			data_reg = OMAP_MCBSP_REG_DRR1;
+		else
+			data_reg = OMAP_MCBSP_REG_DXR1;
+	} else {
+		if (stream)
+			data_reg = OMAP_MCBSP_REG_DRR;
+		else
+			data_reg = OMAP_MCBSP_REG_DXR;
+	}
+
+	return mcbsp->phys_dma_base + data_reg * mcbsp->pdata->reg_step;
+}
+EXPORT_SYMBOL(omap_mcbsp_dma_reg_params);
+
+static void omap_st_on(struct omap_mcbsp *mcbsp)
+{
+	unsigned int w;
+
+	if (mcbsp->pdata->enable_st_clock)
+		mcbsp->pdata->enable_st_clock(mcbsp->id, 1);
+
+	/* Enable McBSP Sidetone */
+	w = MCBSP_READ(mcbsp, SSELCR);
+	MCBSP_WRITE(mcbsp, SSELCR, w | SIDETONEEN);
+
+	/* Enable Sidetone from Sidetone Core */
+	w = MCBSP_ST_READ(mcbsp, SSELCR);
+	MCBSP_ST_WRITE(mcbsp, SSELCR, w | ST_SIDETONEEN);
+}
+
+static void omap_st_off(struct omap_mcbsp *mcbsp)
+{
+	unsigned int w;
+
+	w = MCBSP_ST_READ(mcbsp, SSELCR);
+	MCBSP_ST_WRITE(mcbsp, SSELCR, w & ~(ST_SIDETONEEN));
+
+	w = MCBSP_READ(mcbsp, SSELCR);
+	MCBSP_WRITE(mcbsp, SSELCR, w & ~(SIDETONEEN));
+
+	if (mcbsp->pdata->enable_st_clock)
+		mcbsp->pdata->enable_st_clock(mcbsp->id, 0);
+}
+
+static void omap_st_fir_write(struct omap_mcbsp *mcbsp, s16 *fir)
+{
+	u16 val, i;
+
+	val = MCBSP_ST_READ(mcbsp, SSELCR);
+
+	if (val & ST_COEFFWREN)
+		MCBSP_ST_WRITE(mcbsp, SSELCR, val & ~(ST_COEFFWREN));
+
+	MCBSP_ST_WRITE(mcbsp, SSELCR, val | ST_COEFFWREN);
+
+	for (i = 0; i < 128; i++)
+		MCBSP_ST_WRITE(mcbsp, SFIRCR, fir[i]);
+
+	i = 0;
+
+	val = MCBSP_ST_READ(mcbsp, SSELCR);
+	while (!(val & ST_COEFFWRDONE) && (++i < 1000))
+		val = MCBSP_ST_READ(mcbsp, SSELCR);
+
+	MCBSP_ST_WRITE(mcbsp, SSELCR, val & ~(ST_COEFFWREN));
+
+	if (i == 1000)
+		dev_err(mcbsp->dev, "McBSP FIR load error!\n");
+}
+
+static void omap_st_chgain(struct omap_mcbsp *mcbsp)
+{
+	u16 w;
+	struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
+
+	w = MCBSP_ST_READ(mcbsp, SSELCR);
+
+	MCBSP_ST_WRITE(mcbsp, SGAINCR, ST_CH0GAIN(st_data->ch0gain) | \
+		      ST_CH1GAIN(st_data->ch1gain));
+}
+
+int omap_st_set_chgain(unsigned int id, int channel, s16 chgain)
+{
+	struct omap_mcbsp *mcbsp;
+	struct omap_mcbsp_st_data *st_data;
+	int ret = 0;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+
+	mcbsp = id_to_mcbsp_ptr(id);
+	st_data = mcbsp->st_data;
+
+	if (!st_data)
+		return -ENOENT;
+
+	spin_lock_irq(&mcbsp->lock);
+	if (channel == 0)
+		st_data->ch0gain = chgain;
+	else if (channel == 1)
+		st_data->ch1gain = chgain;
+	else
+		ret = -EINVAL;
+
+	if (st_data->enabled)
+		omap_st_chgain(mcbsp);
+	spin_unlock_irq(&mcbsp->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(omap_st_set_chgain);
+
+int omap_st_get_chgain(unsigned int id, int channel, s16 *chgain)
+{
+	struct omap_mcbsp *mcbsp;
+	struct omap_mcbsp_st_data *st_data;
+	int ret = 0;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+
+	mcbsp = id_to_mcbsp_ptr(id);
+	st_data = mcbsp->st_data;
+
+	if (!st_data)
+		return -ENOENT;
+
+	spin_lock_irq(&mcbsp->lock);
+	if (channel == 0)
+		*chgain = st_data->ch0gain;
+	else if (channel == 1)
+		*chgain = st_data->ch1gain;
+	else
+		ret = -EINVAL;
+	spin_unlock_irq(&mcbsp->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(omap_st_get_chgain);
+
+static int omap_st_start(struct omap_mcbsp *mcbsp)
+{
+	struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
+
+	if (st_data && st_data->enabled && !st_data->running) {
+		omap_st_fir_write(mcbsp, st_data->taps);
+		omap_st_chgain(mcbsp);
+
+		if (!mcbsp->free) {
+			omap_st_on(mcbsp);
+			st_data->running = 1;
+		}
+	}
+
+	return 0;
+}
+
+int omap_st_enable(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	struct omap_mcbsp_st_data *st_data;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+
+	mcbsp = id_to_mcbsp_ptr(id);
+	st_data = mcbsp->st_data;
+
+	if (!st_data)
+		return -ENODEV;
+
+	spin_lock_irq(&mcbsp->lock);
+	st_data->enabled = 1;
+	omap_st_start(mcbsp);
+	spin_unlock_irq(&mcbsp->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(omap_st_enable);
+
+static int omap_st_stop(struct omap_mcbsp *mcbsp)
+{
+	struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
+
+	if (st_data && st_data->running) {
+		if (!mcbsp->free) {
+			omap_st_off(mcbsp);
+			st_data->running = 0;
+		}
+	}
+
+	return 0;
+}
+
+int omap_st_disable(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	struct omap_mcbsp_st_data *st_data;
+	int ret = 0;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+
+	mcbsp = id_to_mcbsp_ptr(id);
+	st_data = mcbsp->st_data;
+
+	if (!st_data)
+		return -ENODEV;
+
+	spin_lock_irq(&mcbsp->lock);
+	omap_st_stop(mcbsp);
+	st_data->enabled = 0;
+	spin_unlock_irq(&mcbsp->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(omap_st_disable);
+
+int omap_st_is_enabled(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	struct omap_mcbsp_st_data *st_data;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+
+	mcbsp = id_to_mcbsp_ptr(id);
+	st_data = mcbsp->st_data;
+
+	if (!st_data)
+		return -ENODEV;
+
+
+	return st_data->enabled;
+}
+EXPORT_SYMBOL(omap_st_is_enabled);
+
+/*
+ * omap_mcbsp_set_rx_threshold configures the transmit threshold in words.
+ * The threshold parameter is 1 based, and it is converted (threshold - 1)
+ * for the THRSH2 register.
+ */
+void omap_mcbsp_set_tx_threshold(unsigned int id, u16 threshold)
+{
+	struct omap_mcbsp *mcbsp;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return;
+
+	if (threshold && threshold <= mcbsp->max_tx_thres)
+		MCBSP_WRITE(mcbsp, THRSH2, threshold - 1);
+}
+EXPORT_SYMBOL(omap_mcbsp_set_tx_threshold);
+
+/*
+ * omap_mcbsp_set_rx_threshold configures the receive threshold in words.
+ * The threshold parameter is 1 based, and it is converted (threshold - 1)
+ * for the THRSH1 register.
+ */
+void omap_mcbsp_set_rx_threshold(unsigned int id, u16 threshold)
+{
+	struct omap_mcbsp *mcbsp;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return;
+
+	if (threshold && threshold <= mcbsp->max_rx_thres)
+		MCBSP_WRITE(mcbsp, THRSH1, threshold - 1);
+}
+EXPORT_SYMBOL(omap_mcbsp_set_rx_threshold);
+
+/*
+ * omap_mcbsp_get_max_tx_thres just return the current configured
+ * maximum threshold for transmission
+ */
+u16 omap_mcbsp_get_max_tx_threshold(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	return mcbsp->max_tx_thres;
+}
+EXPORT_SYMBOL(omap_mcbsp_get_max_tx_threshold);
+
+/*
+ * omap_mcbsp_get_max_rx_thres just return the current configured
+ * maximum threshold for reception
+ */
+u16 omap_mcbsp_get_max_rx_threshold(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	return mcbsp->max_rx_thres;
+}
+EXPORT_SYMBOL(omap_mcbsp_get_max_rx_threshold);
+
+u16 omap_mcbsp_get_fifo_size(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	return mcbsp->pdata->buffer_size;
+}
+EXPORT_SYMBOL(omap_mcbsp_get_fifo_size);
+
+/*
+ * omap_mcbsp_get_tx_delay returns the number of used slots in the McBSP FIFO
+ */
+u16 omap_mcbsp_get_tx_delay(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	u16 buffstat;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return 0;
+
+	/* Returns the number of free locations in the buffer */
+	buffstat = MCBSP_READ(mcbsp, XBUFFSTAT);
+
+	/* Number of slots are different in McBSP ports */
+	return mcbsp->pdata->buffer_size - buffstat;
+}
+EXPORT_SYMBOL(omap_mcbsp_get_tx_delay);
+
+/*
+ * omap_mcbsp_get_rx_delay returns the number of free slots in the McBSP FIFO
+ * to reach the threshold value (when the DMA will be triggered to read it)
+ */
+u16 omap_mcbsp_get_rx_delay(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	u16 buffstat, threshold;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return 0;
+
+	/* Returns the number of used locations in the buffer */
+	buffstat = MCBSP_READ(mcbsp, RBUFFSTAT);
+	/* RX threshold */
+	threshold = MCBSP_READ(mcbsp, THRSH1);
+
+	/* Return the number of location till we reach the threshold limit */
+	if (threshold <= buffstat)
+		return 0;
+	else
+		return threshold - buffstat;
+}
+EXPORT_SYMBOL(omap_mcbsp_get_rx_delay);
+
+/*
+ * omap_mcbsp_get_dma_op_mode just return the current configured
+ * operating mode for the mcbsp channel
+ */
+int omap_mcbsp_get_dma_op_mode(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	int dma_op_mode;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%u)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	dma_op_mode = mcbsp->dma_op_mode;
+
+	return dma_op_mode;
+}
+EXPORT_SYMBOL(omap_mcbsp_get_dma_op_mode);
+
+int omap_mcbsp_request(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	void *reg_cache;
+	int err;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return -ENODEV;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	reg_cache = kzalloc(mcbsp->reg_cache_size, GFP_KERNEL);
+	if (!reg_cache) {
+		return -ENOMEM;
+	}
+
+	spin_lock(&mcbsp->lock);
+	if (!mcbsp->free) {
+		dev_err(mcbsp->dev, "McBSP%d is currently in use\n",
+			mcbsp->id);
+		err = -EBUSY;
+		goto err_kfree;
+	}
+
+	mcbsp->free = false;
+	mcbsp->reg_cache = reg_cache;
+	spin_unlock(&mcbsp->lock);
+
+	if (mcbsp->pdata && mcbsp->pdata->ops && mcbsp->pdata->ops->request)
+		mcbsp->pdata->ops->request(id);
+
+	pm_runtime_get_sync(mcbsp->dev);
+
+	/* Enable wakeup behavior */
+	if (mcbsp->pdata->has_wakeup)
+		MCBSP_WRITE(mcbsp, WAKEUPEN, XRDYEN | RRDYEN);
+
+	/*
+	 * Make sure that transmitter, receiver and sample-rate generator are
+	 * not running before activating IRQs.
+	 */
+	MCBSP_WRITE(mcbsp, SPCR1, 0);
+	MCBSP_WRITE(mcbsp, SPCR2, 0);
+
+	err = request_irq(mcbsp->tx_irq, omap_mcbsp_tx_irq_handler,
+				0, "McBSP", (void *)mcbsp);
+	if (err != 0) {
+		dev_err(mcbsp->dev, "Unable to request TX IRQ %d "
+				"for McBSP%d\n", mcbsp->tx_irq,
+				mcbsp->id);
+		goto err_clk_disable;
+	}
+
+	if (mcbsp->rx_irq) {
+		err = request_irq(mcbsp->rx_irq,
+				omap_mcbsp_rx_irq_handler,
+				0, "McBSP", (void *)mcbsp);
+		if (err != 0) {
+			dev_err(mcbsp->dev, "Unable to request RX IRQ %d "
+					"for McBSP%d\n", mcbsp->rx_irq,
+					mcbsp->id);
+			goto err_free_irq;
+		}
+	}
+
+	return 0;
+err_free_irq:
+	free_irq(mcbsp->tx_irq, (void *)mcbsp);
+err_clk_disable:
+	if (mcbsp->pdata && mcbsp->pdata->ops && mcbsp->pdata->ops->free)
+		mcbsp->pdata->ops->free(id);
+
+	/* Disable wakeup behavior */
+	if (mcbsp->pdata->has_wakeup)
+		MCBSP_WRITE(mcbsp, WAKEUPEN, 0);
+
+	pm_runtime_put_sync(mcbsp->dev);
+
+	spin_lock(&mcbsp->lock);
+	mcbsp->free = true;
+	mcbsp->reg_cache = NULL;
+err_kfree:
+	spin_unlock(&mcbsp->lock);
+	kfree(reg_cache);
+
+	return err;
+}
+EXPORT_SYMBOL(omap_mcbsp_request);
+
+void omap_mcbsp_free(unsigned int id)
+{
+	struct omap_mcbsp *mcbsp;
+	void *reg_cache;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	if (mcbsp->pdata && mcbsp->pdata->ops && mcbsp->pdata->ops->free)
+		mcbsp->pdata->ops->free(id);
+
+	/* Disable wakeup behavior */
+	if (mcbsp->pdata->has_wakeup)
+		MCBSP_WRITE(mcbsp, WAKEUPEN, 0);
+
+	pm_runtime_put_sync(mcbsp->dev);
+
+	if (mcbsp->rx_irq)
+		free_irq(mcbsp->rx_irq, (void *)mcbsp);
+	free_irq(mcbsp->tx_irq, (void *)mcbsp);
+
+	reg_cache = mcbsp->reg_cache;
+
+	spin_lock(&mcbsp->lock);
+	if (mcbsp->free)
+		dev_err(mcbsp->dev, "McBSP%d was not reserved\n", mcbsp->id);
+	else
+		mcbsp->free = true;
+	mcbsp->reg_cache = NULL;
+	spin_unlock(&mcbsp->lock);
+
+	if (reg_cache)
+		kfree(reg_cache);
+}
+EXPORT_SYMBOL(omap_mcbsp_free);
+
+/*
+ * Here we start the McBSP, by enabling transmitter, receiver or both.
+ * If no transmitter or receiver is active prior calling, then sample-rate
+ * generator and frame sync are started.
+ */
+void omap_mcbsp_start(unsigned int id, int tx, int rx)
+{
+	struct omap_mcbsp *mcbsp;
+	int enable_srg = 0;
+	u16 w;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	if (mcbsp->st_data)
+		omap_st_start(mcbsp);
+
+	/* Only enable SRG, if McBSP is master */
+	w = MCBSP_READ_CACHE(mcbsp, PCR0);
+	if (w & (FSXM | FSRM | CLKXM | CLKRM))
+		enable_srg = !((MCBSP_READ_CACHE(mcbsp, SPCR2) |
+				MCBSP_READ_CACHE(mcbsp, SPCR1)) & 1);
+
+	if (enable_srg) {
+		/* Start the sample generator */
+		w = MCBSP_READ_CACHE(mcbsp, SPCR2);
+		MCBSP_WRITE(mcbsp, SPCR2, w | (1 << 6));
+	}
+
+	/* Enable transmitter and receiver */
+	tx &= 1;
+	w = MCBSP_READ_CACHE(mcbsp, SPCR2);
+	MCBSP_WRITE(mcbsp, SPCR2, w | tx);
+
+	rx &= 1;
+	w = MCBSP_READ_CACHE(mcbsp, SPCR1);
+	MCBSP_WRITE(mcbsp, SPCR1, w | rx);
+
+	/*
+	 * Worst case: CLKSRG*2 = 8000khz: (1/8000) * 2 * 2 usec
+	 * REVISIT: 100us may give enough time for two CLKSRG, however
+	 * due to some unknown PM related, clock gating etc. reason it
+	 * is now at 500us.
+	 */
+	udelay(500);
+
+	if (enable_srg) {
+		/* Start frame sync */
+		w = MCBSP_READ_CACHE(mcbsp, SPCR2);
+		MCBSP_WRITE(mcbsp, SPCR2, w | (1 << 7));
+	}
+
+	if (mcbsp->pdata->has_ccr) {
+		/* Release the transmitter and receiver */
+		w = MCBSP_READ_CACHE(mcbsp, XCCR);
+		w &= ~(tx ? XDISABLE : 0);
+		MCBSP_WRITE(mcbsp, XCCR, w);
+		w = MCBSP_READ_CACHE(mcbsp, RCCR);
+		w &= ~(rx ? RDISABLE : 0);
+		MCBSP_WRITE(mcbsp, RCCR, w);
+	}
+
+	/* Dump McBSP Regs */
+	omap_mcbsp_dump_reg(id);
+}
+EXPORT_SYMBOL(omap_mcbsp_start);
+
+void omap_mcbsp_stop(unsigned int id, int tx, int rx)
+{
+	struct omap_mcbsp *mcbsp;
+	int idle;
+	u16 w;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
+		return;
+	}
+
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	/* Reset transmitter */
+	tx &= 1;
+	if (mcbsp->pdata->has_ccr) {
+		w = MCBSP_READ_CACHE(mcbsp, XCCR);
+		w |= (tx ? XDISABLE : 0);
+		MCBSP_WRITE(mcbsp, XCCR, w);
+	}
+	w = MCBSP_READ_CACHE(mcbsp, SPCR2);
+	MCBSP_WRITE(mcbsp, SPCR2, w & ~tx);
+
+	/* Reset receiver */
+	rx &= 1;
+	if (mcbsp->pdata->has_ccr) {
+		w = MCBSP_READ_CACHE(mcbsp, RCCR);
+		w |= (rx ? RDISABLE : 0);
+		MCBSP_WRITE(mcbsp, RCCR, w);
+	}
+	w = MCBSP_READ_CACHE(mcbsp, SPCR1);
+	MCBSP_WRITE(mcbsp, SPCR1, w & ~rx);
+
+	idle = !((MCBSP_READ_CACHE(mcbsp, SPCR2) |
+			MCBSP_READ_CACHE(mcbsp, SPCR1)) & 1);
+
+	if (idle) {
+		/* Reset the sample rate generator */
+		w = MCBSP_READ_CACHE(mcbsp, SPCR2);
+		MCBSP_WRITE(mcbsp, SPCR2, w & ~(1 << 6));
+	}
+
+	if (mcbsp->st_data)
+		omap_st_stop(mcbsp);
+}
+EXPORT_SYMBOL(omap_mcbsp_stop);
+
+int omap2_mcbsp_set_clks_src(u8 id, u8 fck_src_id)
+{
+	struct omap_mcbsp *mcbsp;
+	const char *src;
+
+	if (!omap_mcbsp_check_valid_id(id)) {
+		pr_err("%s: Invalid id (%d)\n", __func__, id + 1);
+		return -EINVAL;
+	}
+	mcbsp = id_to_mcbsp_ptr(id);
+
+	if (fck_src_id == MCBSP_CLKS_PAD_SRC)
+		src = "clks_ext";
+	else if (fck_src_id == MCBSP_CLKS_PRCM_SRC)
+		src = "clks_fclk";
+	else
+		return -EINVAL;
+
+	if (mcbsp->pdata->set_clk_src)
+		return mcbsp->pdata->set_clk_src(mcbsp->dev, mcbsp->fclk, src);
+	else
+		return -EINVAL;
+}
+EXPORT_SYMBOL(omap2_mcbsp_set_clks_src);
+
+void omap2_mcbsp1_mux_clkr_src(u8 mux)
+{
+	struct omap_mcbsp *mcbsp;
+	const char *src;
+
+	if (mux == CLKR_SRC_CLKR)
+		src = "clkr";
+	else if (mux == CLKR_SRC_CLKX)
+		src = "clkx";
+	else
+		return;
+
+	mcbsp = id_to_mcbsp_ptr(0);
+	if (mcbsp->pdata->mux_signal)
+		mcbsp->pdata->mux_signal(mcbsp->dev, "clkr", src);
+}
+EXPORT_SYMBOL(omap2_mcbsp1_mux_clkr_src);
+
+void omap2_mcbsp1_mux_fsr_src(u8 mux)
+{
+	struct omap_mcbsp *mcbsp;
+	const char *src;
+
+	if (mux == FSR_SRC_FSR)
+		src = "fsr";
+	else if (mux == FSR_SRC_FSX)
+		src = "fsx";
+	else
+		return;
+
+	mcbsp = id_to_mcbsp_ptr(0);
+	if (mcbsp->pdata->mux_signal)
+		mcbsp->pdata->mux_signal(mcbsp->dev, "fsr", src);
+}
+EXPORT_SYMBOL(omap2_mcbsp1_mux_fsr_src);
+
+#define max_thres(m)			(mcbsp->pdata->buffer_size)
+#define valid_threshold(m, val)		((val) <= max_thres(m))
+#define THRESHOLD_PROP_BUILDER(prop)					\
+static ssize_t prop##_show(struct device *dev,				\
+			struct device_attribute *attr, char *buf)	\
+{									\
+	struct omap_mcbsp *mcbsp = dev_get_drvdata(dev);		\
+									\
+	return sprintf(buf, "%u\n", mcbsp->prop);			\
+}									\
+									\
+static ssize_t prop##_store(struct device *dev,				\
+				struct device_attribute *attr,		\
+				const char *buf, size_t size)		\
+{									\
+	struct omap_mcbsp *mcbsp = dev_get_drvdata(dev);		\
+	unsigned long val;						\
+	int status;							\
+									\
+	status = strict_strtoul(buf, 0, &val);				\
+	if (status)							\
+		return status;						\
+									\
+	if (!valid_threshold(mcbsp, val))				\
+		return -EDOM;						\
+									\
+	mcbsp->prop = val;						\
+	return size;							\
+}									\
+									\
+static DEVICE_ATTR(prop, 0644, prop##_show, prop##_store);
+
+THRESHOLD_PROP_BUILDER(max_tx_thres);
+THRESHOLD_PROP_BUILDER(max_rx_thres);
+
+static const char *dma_op_modes[] = {
+	"element", "threshold", "frame",
+};
+
+static ssize_t dma_op_mode_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct omap_mcbsp *mcbsp = dev_get_drvdata(dev);
+	int dma_op_mode, i = 0;
+	ssize_t len = 0;
+	const char * const *s;
+
+	dma_op_mode = mcbsp->dma_op_mode;
+
+	for (s = &dma_op_modes[i]; i < ARRAY_SIZE(dma_op_modes); s++, i++) {
+		if (dma_op_mode == i)
+			len += sprintf(buf + len, "[%s] ", *s);
+		else
+			len += sprintf(buf + len, "%s ", *s);
+	}
+	len += sprintf(buf + len, "\n");
+
+	return len;
+}
+
+static ssize_t dma_op_mode_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t size)
+{
+	struct omap_mcbsp *mcbsp = dev_get_drvdata(dev);
+	const char * const *s;
+	int i = 0;
+
+	for (s = &dma_op_modes[i]; i < ARRAY_SIZE(dma_op_modes); s++, i++)
+		if (sysfs_streq(buf, *s))
+			break;
+
+	if (i == ARRAY_SIZE(dma_op_modes))
+		return -EINVAL;
+
+	spin_lock_irq(&mcbsp->lock);
+	if (!mcbsp->free) {
+		size = -EBUSY;
+		goto unlock;
+	}
+	mcbsp->dma_op_mode = i;
+
+unlock:
+	spin_unlock_irq(&mcbsp->lock);
+
+	return size;
+}
+
+static DEVICE_ATTR(dma_op_mode, 0644, dma_op_mode_show, dma_op_mode_store);
+
+static const struct attribute *additional_attrs[] = {
+	&dev_attr_max_tx_thres.attr,
+	&dev_attr_max_rx_thres.attr,
+	&dev_attr_dma_op_mode.attr,
+	NULL,
+};
+
+static const struct attribute_group additional_attr_group = {
+	.attrs = (struct attribute **)additional_attrs,
+};
+
+static ssize_t st_taps_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct omap_mcbsp *mcbsp = dev_get_drvdata(dev);
+	struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
+	ssize_t status = 0;
+	int i;
+
+	spin_lock_irq(&mcbsp->lock);
+	for (i = 0; i < st_data->nr_taps; i++)
+		status += sprintf(&buf[status], (i ? ", %d" : "%d"),
+				  st_data->taps[i]);
+	if (i)
+		status += sprintf(&buf[status], "\n");
+	spin_unlock_irq(&mcbsp->lock);
+
+	return status;
+}
+
+static ssize_t st_taps_store(struct device *dev,
+			     struct device_attribute *attr,
+			     const char *buf, size_t size)
+{
+	struct omap_mcbsp *mcbsp = dev_get_drvdata(dev);
+	struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
+	int val, tmp, status, i = 0;
+
+	spin_lock_irq(&mcbsp->lock);
+	memset(st_data->taps, 0, sizeof(st_data->taps));
+	st_data->nr_taps = 0;
+
+	do {
+		status = sscanf(buf, "%d%n", &val, &tmp);
+		if (status < 0 || status == 0) {
+			size = -EINVAL;
+			goto out;
+		}
+		if (val < -32768 || val > 32767) {
+			size = -EINVAL;
+			goto out;
+		}
+		st_data->taps[i++] = val;
+		buf += tmp;
+		if (*buf != ',')
+			break;
+		buf++;
+	} while (1);
+
+	st_data->nr_taps = i;
+
+out:
+	spin_unlock_irq(&mcbsp->lock);
+
+	return size;
+}
+
+static DEVICE_ATTR(st_taps, 0644, st_taps_show, st_taps_store);
+
+static const struct attribute *sidetone_attrs[] = {
+	&dev_attr_st_taps.attr,
+	NULL,
+};
+
+static const struct attribute_group sidetone_attr_group = {
+	.attrs = (struct attribute **)sidetone_attrs,
+};
+
+static int __devinit omap_st_add(struct omap_mcbsp *mcbsp,
+				 struct resource *res)
+{
+	struct omap_mcbsp_st_data *st_data;
+	int err;
+
+	st_data = kzalloc(sizeof(*mcbsp->st_data), GFP_KERNEL);
+	if (!st_data) {
+		err = -ENOMEM;
+		goto err1;
+	}
+
+	st_data->io_base_st = ioremap(res->start, resource_size(res));
+	if (!st_data->io_base_st) {
+		err = -ENOMEM;
+		goto err2;
+	}
+
+	err = sysfs_create_group(&mcbsp->dev->kobj, &sidetone_attr_group);
+	if (err)
+		goto err3;
+
+	mcbsp->st_data = st_data;
+	return 0;
+
+err3:
+	iounmap(st_data->io_base_st);
+err2:
+	kfree(st_data);
+err1:
+	return err;
+
+}
+
+static void __devexit omap_st_remove(struct omap_mcbsp *mcbsp)
+{
+	struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
+
+	sysfs_remove_group(&mcbsp->dev->kobj, &sidetone_attr_group);
+	iounmap(st_data->io_base_st);
+	kfree(st_data);
+}
+
+/*
+ * McBSP1 and McBSP3 are directly mapped on 1610 and 1510.
+ * 730 has only 2 McBSP, and both of them are MPU peripherals.
+ */
+static int __devinit omap_mcbsp_probe(struct platform_device *pdev)
+{
+	struct omap_mcbsp_platform_data *pdata = pdev->dev.platform_data;
+	struct omap_mcbsp *mcbsp;
+	int id = pdev->id - 1;
+	struct resource *res;
+	int ret = 0;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "McBSP device initialized without"
+				"platform data\n");
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	dev_dbg(&pdev->dev, "Initializing OMAP McBSP (%d).\n", pdev->id);
+
+	if (id >= omap_mcbsp_count) {
+		dev_err(&pdev->dev, "Invalid McBSP device id (%d)\n", id);
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	mcbsp = kzalloc(sizeof(struct omap_mcbsp), GFP_KERNEL);
+	if (!mcbsp) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	spin_lock_init(&mcbsp->lock);
+	mcbsp->id = id + 1;
+	mcbsp->free = true;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpu");
+	if (!res) {
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+		if (!res) {
+			dev_err(&pdev->dev, "%s:mcbsp%d has invalid memory"
+					"resource\n", __func__, pdev->id);
+			ret = -ENOMEM;
+			goto exit;
+		}
+	}
+	mcbsp->phys_base = res->start;
+	mcbsp->reg_cache_size = resource_size(res);
+	mcbsp->io_base = ioremap(res->start, resource_size(res));
+	if (!mcbsp->io_base) {
+		ret = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dma");
+	if (!res)
+		mcbsp->phys_dma_base = mcbsp->phys_base;
+	else
+		mcbsp->phys_dma_base = res->start;
+
+	mcbsp->tx_irq = platform_get_irq_byname(pdev, "tx");
+	mcbsp->rx_irq = platform_get_irq_byname(pdev, "rx");
+
+	/* From OMAP4 there will be a single irq line */
+	if (mcbsp->tx_irq == -ENXIO)
+		mcbsp->tx_irq = platform_get_irq(pdev, 0);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
+	if (!res) {
+		dev_err(&pdev->dev, "%s:mcbsp%d has invalid rx DMA channel\n",
+					__func__, pdev->id);
+		ret = -ENODEV;
+		goto err_res;
+	}
+	mcbsp->dma_rx_sync = res->start;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
+	if (!res) {
+		dev_err(&pdev->dev, "%s:mcbsp%d has invalid tx DMA channel\n",
+					__func__, pdev->id);
+		ret = -ENODEV;
+		goto err_res;
+	}
+	mcbsp->dma_tx_sync = res->start;
+
+	mcbsp->fclk = clk_get(&pdev->dev, "fck");
+	if (IS_ERR(mcbsp->fclk)) {
+		ret = PTR_ERR(mcbsp->fclk);
+		dev_err(&pdev->dev, "unable to get fck: %d\n", ret);
+		goto err_res;
+	}
+
+	mcbsp->pdata = pdata;
+	mcbsp->dev = &pdev->dev;
+	mcbsp_ptr[id] = mcbsp;
+	platform_set_drvdata(pdev, mcbsp);
+	pm_runtime_enable(mcbsp->dev);
+
+	mcbsp->dma_op_mode = MCBSP_DMA_MODE_ELEMENT;
+	if (mcbsp->pdata->buffer_size) {
+		/*
+		 * Initially configure the maximum thresholds to a safe value.
+		 * The McBSP FIFO usage with these values should not go under
+		 * 16 locations.
+		 * If the whole FIFO without safety buffer is used, than there
+		 * is a possibility that the DMA will be not able to push the
+		 * new data on time, causing channel shifts in runtime.
+		 */
+		mcbsp->max_tx_thres = max_thres(mcbsp) - 0x10;
+		mcbsp->max_rx_thres = max_thres(mcbsp) - 0x10;
+
+		ret = sysfs_create_group(&mcbsp->dev->kobj,
+					 &additional_attr_group);
+		if (ret) {
+			dev_err(mcbsp->dev,
+				"Unable to create additional controls\n");
+			goto err_thres;
+		}
+	} else {
+		mcbsp->max_tx_thres = -EINVAL;
+		mcbsp->max_rx_thres = -EINVAL;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sidetone");
+	if (res) {
+		ret = omap_st_add(mcbsp, res);
+		if (ret) {
+			dev_err(mcbsp->dev,
+				"Unable to create sidetone controls\n");
+			goto err_st;
+		}
+	}
+
+	return 0;
+
+err_st:
+	if (mcbsp->pdata->buffer_size)
+		sysfs_remove_group(&mcbsp->dev->kobj,
+				   &additional_attr_group);
+err_thres:
+	clk_put(mcbsp->fclk);
+err_res:
+	iounmap(mcbsp->io_base);
+err_ioremap:
+	kfree(mcbsp);
+exit:
+	return ret;
+}
+
+static int __devexit omap_mcbsp_remove(struct platform_device *pdev)
+{
+	struct omap_mcbsp *mcbsp = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+	if (mcbsp) {
+
+		if (mcbsp->pdata && mcbsp->pdata->ops &&
+				mcbsp->pdata->ops->free)
+			mcbsp->pdata->ops->free(mcbsp->id);
+
+		if (mcbsp->pdata->buffer_size)
+			sysfs_remove_group(&mcbsp->dev->kobj,
+					   &additional_attr_group);
+
+		if (mcbsp->st_data)
+			omap_st_remove(mcbsp);
+
+		clk_put(mcbsp->fclk);
+
+		iounmap(mcbsp->io_base);
+		kfree(mcbsp);
+	}
+
+	return 0;
+}
+
+static struct platform_driver omap_mcbsp_driver = {
+	.probe		= omap_mcbsp_probe,
+	.remove		= __devexit_p(omap_mcbsp_remove),
+	.driver		= {
+		.name	= "omap-mcbsp",
+	},
+};
+
+module_platform_driver(omap_mcbsp_driver);
+
+MODULE_AUTHOR("Samuel Ortiz <samuel.ortiz@nokia.com>");
+MODULE_DESCRIPTION("OMAP McBSP core driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:omap-mcbsp");