/*
 * 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 <linux/pm_runtime.h>

#include <linux/platform_data/asoc-ti-mcbsp.h>

#include "mcbsp.h"

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;
                writew_relaxed((u16)val, addr);
        } else {
                ((u32 *)mcbsp->reg_cache)[reg] = val;
                writel_relaxed(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 ? readw_relaxed(addr) :
                                     ((u16 *)mcbsp->reg_cache)[reg];
        } else {
                return !from_cache ? readl_relaxed(addr) :
                                     ((u32 *)mcbsp->reg_cache)[reg];
        }
}

static void omap_mcbsp_st_write(struct omap_mcbsp *mcbsp, u16 reg, u32 val)
{
        writel_relaxed(val, mcbsp->st_data->io_base_st + reg);
}

static int omap_mcbsp_st_read(struct omap_mcbsp *mcbsp, u16 reg)
{
        return readl_relaxed(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(struct omap_mcbsp *mcbsp)
{
        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_irq_handler(int irq, void *dev_id)
{
        struct omap_mcbsp *mcbsp = dev_id;
        u16 irqst;

        irqst = MCBSP_READ(mcbsp, IRQST);
        dev_dbg(mcbsp->dev, "IRQ callback : 0x%x\n", irqst);

        if (irqst & RSYNCERREN)
                dev_err(mcbsp->dev, "RX Frame Sync Error!\n");
        if (irqst & RFSREN)
                dev_dbg(mcbsp->dev, "RX Frame Sync\n");
        if (irqst & REOFEN)
                dev_dbg(mcbsp->dev, "RX End Of Frame\n");
        if (irqst & RRDYEN)
                dev_dbg(mcbsp->dev, "RX Buffer Threshold Reached\n");
        if (irqst & RUNDFLEN)
                dev_err(mcbsp->dev, "RX Buffer Underflow!\n");
        if (irqst & ROVFLEN)
                dev_err(mcbsp->dev, "RX Buffer Overflow!\n");

        if (irqst & XSYNCERREN)
                dev_err(mcbsp->dev, "TX Frame Sync Error!\n");
        if (irqst & XFSXEN)
                dev_dbg(mcbsp->dev, "TX Frame Sync\n");
        if (irqst & XEOFEN)
                dev_dbg(mcbsp->dev, "TX End Of Frame\n");
        if (irqst & XRDYEN)
                dev_dbg(mcbsp->dev, "TX Buffer threshold Reached\n");
        if (irqst & XUNDFLEN)
                dev_err(mcbsp->dev, "TX Buffer Underflow!\n");
        if (irqst & XOVFLEN)
                dev_err(mcbsp->dev, "TX Buffer Overflow!\n");
        if (irqst & XEMPTYEOFEN)
                dev_dbg(mcbsp->dev, "TX Buffer empty at end of frame\n");

        MCBSP_WRITE(mcbsp, IRQST, irqst);

        return IRQ_HANDLED;
}

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(struct omap_mcbsp *mcbsp,
                       const struct omap_mcbsp_reg_cfg *config)
{
        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);
        }
        /* Enable wakeup behavior */
        if (mcbsp->pdata->has_wakeup)
                MCBSP_WRITE(mcbsp, WAKEUPEN, XRDYEN | RRDYEN);

        /* Enable TX/RX sync error interrupts by default */
        if (mcbsp->irq)
                MCBSP_WRITE(mcbsp, IRQEN, RSYNCERREN | XSYNCERREN |
                            RUNDFLEN | ROVFLEN | XUNDFLEN | XOVFLEN);
}

/**
 * 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
 */
static int omap_mcbsp_dma_reg_params(struct omap_mcbsp *mcbsp,
                                     unsigned int stream)
{
        int data_reg;

        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;
}

static void omap_st_on(struct omap_mcbsp *mcbsp)
{
        unsigned int w;

        if (mcbsp->pdata->force_ick_on)
                mcbsp->pdata->force_ick_on(mcbsp->st_data->mcbsp_iclk, true);

        /* Disable Sidetone clock auto-gating for normal operation */
        w = MCBSP_ST_READ(mcbsp, SYSCONFIG);
        MCBSP_ST_WRITE(mcbsp, SYSCONFIG, w & ~(ST_AUTOIDLE));

        /* 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));

        /* Enable Sidetone clock auto-gating to reduce power consumption */
        w = MCBSP_ST_READ(mcbsp, SYSCONFIG);
        MCBSP_ST_WRITE(mcbsp, SYSCONFIG, w | ST_AUTOIDLE);

        if (mcbsp->pdata->force_ick_on)
                mcbsp->pdata->force_ick_on(mcbsp->st_data->mcbsp_iclk, false);
}

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(struct omap_mcbsp *mcbsp, int channel, s16 chgain)
{
        struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
        int ret = 0;

        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;
}

int omap_st_get_chgain(struct omap_mcbsp *mcbsp, int channel, s16 *chgain)
{
        struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
        int ret = 0;

        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;
}

static int omap_st_start(struct omap_mcbsp *mcbsp)
{
        struct omap_mcbsp_st_data *st_data = mcbsp->st_data;

        if (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(struct omap_mcbsp *mcbsp)
{
        struct omap_mcbsp_st_data *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;
}

static int omap_st_stop(struct omap_mcbsp *mcbsp)
{
        struct omap_mcbsp_st_data *st_data = mcbsp->st_data;

        if (st_data->running) {
                if (!mcbsp->free) {
                        omap_st_off(mcbsp);
                        st_data->running = 0;
                }
        }

        return 0;
}

int omap_st_disable(struct omap_mcbsp *mcbsp)
{
        struct omap_mcbsp_st_data *st_data = mcbsp->st_data;
        int ret = 0;

        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;
}

int omap_st_is_enabled(struct omap_mcbsp *mcbsp)
{
        struct omap_mcbsp_st_data *st_data = mcbsp->st_data;

        if (!st_data)
                return -ENODEV;

        return st_data->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(struct omap_mcbsp *mcbsp, u16 threshold)
{
        if (mcbsp->pdata->buffer_size == 0)
                return;

        if (threshold && threshold <= mcbsp->max_tx_thres)
                MCBSP_WRITE(mcbsp, THRSH2, threshold - 1);
}

/*
 * 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(struct omap_mcbsp *mcbsp, u16 threshold)
{
        if (mcbsp->pdata->buffer_size == 0)
                return;

        if (threshold && threshold <= mcbsp->max_rx_thres)
                MCBSP_WRITE(mcbsp, THRSH1, threshold - 1);
}

/*
 * omap_mcbsp_get_tx_delay returns the number of used slots in the McBSP FIFO
 */
u16 omap_mcbsp_get_tx_delay(struct omap_mcbsp *mcbsp)
{
        u16 buffstat;

        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;
}

/*
 * 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(struct omap_mcbsp *mcbsp)
{
        u16 buffstat, threshold;

        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;
}

int omap_mcbsp_request(struct omap_mcbsp *mcbsp)
{
        void *reg_cache;
        int err;

        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(mcbsp->id - 1);

        /*
         * 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);

        if (mcbsp->irq) {
                err = request_irq(mcbsp->irq, omap_mcbsp_irq_handler, 0,
                                  "McBSP", (void *)mcbsp);
                if (err != 0) {
                        dev_err(mcbsp->dev, "Unable to request IRQ\n");
                        goto err_clk_disable;
                }
        } else {
                err = request_irq(mcbsp->tx_irq, omap_mcbsp_tx_irq_handler, 0,
                                  "McBSP TX", (void *)mcbsp);
                if (err != 0) {
                        dev_err(mcbsp->dev, "Unable to request TX IRQ\n");
                        goto err_clk_disable;
                }

                err = request_irq(mcbsp->rx_irq, omap_mcbsp_rx_irq_handler, 0,
                                  "McBSP RX", (void *)mcbsp);
                if (err != 0) {
                        dev_err(mcbsp->dev, "Unable to request RX IRQ\n");
                        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(mcbsp->id - 1);

        /* Disable wakeup behavior */
        if (mcbsp->pdata->has_wakeup)
                MCBSP_WRITE(mcbsp, WAKEUPEN, 0);

        spin_lock(&mcbsp->lock);
        mcbsp->free = true;
        mcbsp->reg_cache = NULL;
err_kfree:
        spin_unlock(&mcbsp->lock);
        kfree(reg_cache);

        return err;
}

void omap_mcbsp_free(struct omap_mcbsp *mcbsp)
{
        void *reg_cache;

        if (mcbsp->pdata && mcbsp->pdata->ops && mcbsp->pdata->ops->free)
                mcbsp->pdata->ops->free(mcbsp->id - 1);

        /* Disable wakeup behavior */
        if (mcbsp->pdata->has_wakeup)
                MCBSP_WRITE(mcbsp, WAKEUPEN, 0);

        /* Disable interrupt requests */
        if (mcbsp->irq)
                MCBSP_WRITE(mcbsp, IRQEN, 0);

        if (mcbsp->irq) {
                free_irq(mcbsp->irq, (void *)mcbsp);
        } else {
                free_irq(mcbsp->rx_irq, (void *)mcbsp);
                free_irq(mcbsp->tx_irq, (void *)mcbsp);
        }

        reg_cache = mcbsp->reg_cache;

        /*
         * Select CLKS source from internal source unconditionally before
         * marking the McBSP port as free.
         * If the external clock source via MCBSP_CLKS pin has been selected the
         * system will refuse to enter idle if the CLKS pin source is not reset
         * back to internal source.
         */
        if (!mcbsp_omap1())
                omap2_mcbsp_set_clks_src(mcbsp, MCBSP_CLKS_PRCM_SRC);

        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);

        kfree(reg_cache);
}

/*
 * 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(struct omap_mcbsp *mcbsp, int tx, int rx)
{
        int enable_srg = 0;
        u16 w;

        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(mcbsp);
}

void omap_mcbsp_stop(struct omap_mcbsp *mcbsp, int tx, int rx)
{
        int idle;
        u16 w;

        /* 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);
}

int omap2_mcbsp_set_clks_src(struct omap_mcbsp *mcbsp, u8 fck_src_id)
{
        struct clk *fck_src;
        const char *src;
        int r;

        if (fck_src_id == MCBSP_CLKS_PAD_SRC)
                src = "pad_fck";
        else if (fck_src_id == MCBSP_CLKS_PRCM_SRC)
                src = "prcm_fck";
        else
                return -EINVAL;

        fck_src = clk_get(mcbsp->dev, src);
        if (IS_ERR(fck_src)) {
                dev_err(mcbsp->dev, "CLKS: could not clk_get() %s\n", src);
                return -EINVAL;
        }

        pm_runtime_put_sync(mcbsp->dev);

        r = clk_set_parent(mcbsp->fclk, fck_src);
        if (r) {
                dev_err(mcbsp->dev, "CLKS: could not clk_set_parent() to %s\n",
                        src);
                clk_put(fck_src);
                return r;
        }

        pm_runtime_get_sync(mcbsp->dev);

        clk_put(fck_src);

        return 0;

}

#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 = kstrtoul(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",
};

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 omap_st_add(struct omap_mcbsp *mcbsp, struct resource *res)
{
        struct omap_mcbsp_st_data *st_data;
        int err;

        st_data = devm_kzalloc(mcbsp->dev, sizeof(*mcbsp->st_data), GFP_KERNEL);
        if (!st_data)
                return -ENOMEM;

        st_data->mcbsp_iclk = clk_get(mcbsp->dev, "ick");
        if (IS_ERR(st_data->mcbsp_iclk)) {
                dev_warn(mcbsp->dev,
                         "Failed to get ick, sidetone might be broken\n");
                st_data->mcbsp_iclk = NULL;
        }

        st_data->io_base_st = devm_ioremap(mcbsp->dev, res->start,
                                           resource_size(res));
        if (!st_data->io_base_st)
                return -ENOMEM;

        err = sysfs_create_group(&mcbsp->dev->kobj, &sidetone_attr_group);
        if (err)
                return err;

        mcbsp->st_data = st_data;
        return 0;
}

/*
 * McBSP1 and McBSP3 are directly mapped on 1610 and 1510.
 * 730 has only 2 McBSP, and both of them are MPU peripherals.
 */
int omap_mcbsp_init(struct platform_device *pdev)
{
        struct omap_mcbsp *mcbsp = platform_get_drvdata(pdev);
        struct resource *res;
        int ret = 0;

        spin_lock_init(&mcbsp->lock);
        mcbsp->free = true;

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpu");
        if (!res)
                res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

        mcbsp->io_base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(mcbsp->io_base))
                return PTR_ERR(mcbsp->io_base);

        mcbsp->phys_base = res->start;
        mcbsp->reg_cache_size = resource_size(res);

        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;

        /*

         * OMAP1, 2 uses two interrupt lines: TX, RX
         * OMAP2430, OMAP3 SoC have combined IRQ line as well.
         * OMAP4 and newer SoC only have the combined IRQ line.
         * Use the combined IRQ if available since it gives better debugging
         * possibilities.
         */
        mcbsp->irq = platform_get_irq_byname(pdev, "common");
        if (mcbsp->irq == -ENXIO) {
                mcbsp->tx_irq = platform_get_irq_byname(pdev, "tx");

                if (mcbsp->tx_irq == -ENXIO) {
                        mcbsp->irq = platform_get_irq(pdev, 0);
                        mcbsp->tx_irq = 0;
                } else {
                        mcbsp->rx_irq = platform_get_irq_byname(pdev, "rx");
                        mcbsp->irq = 0;
                }
        }

        if (!pdev->dev.of_node) {
                res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
                if (!res) {
                        dev_err(&pdev->dev, "invalid tx DMA channel\n");
                        return -ENODEV;
                }
                mcbsp->dma_req[0] = res->start;
                mcbsp->dma_data[0].filter_data = &mcbsp->dma_req[0];

                res = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
                if (!res) {
                        dev_err(&pdev->dev, "invalid rx DMA channel\n");
                        return -ENODEV;
                }
                mcbsp->dma_req[1] = res->start;
                mcbsp->dma_data[1].filter_data = &mcbsp->dma_req[1];
        } else {
                mcbsp->dma_data[0].filter_data = "tx";
                mcbsp->dma_data[1].filter_data = "rx";
        }

        mcbsp->dma_data[0].addr = omap_mcbsp_dma_reg_params(mcbsp, 0);
        mcbsp->dma_data[0].maxburst = 4;

        mcbsp->dma_data[1].addr = omap_mcbsp_dma_reg_params(mcbsp, 1);
        mcbsp->dma_data[1].maxburst = 4;

        mcbsp->fclk = clk_get(&pdev->dev, "fck");
        if (IS_ERR(mcbsp->fclk)) {
                ret = PTR_ERR(mcbsp->fclk);
                dev_err(mcbsp->dev, "unable to get fck: %d\n", ret);
                return ret;
        }

        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);
        return ret;
}

void omap_mcbsp_cleanup(struct omap_mcbsp *mcbsp)
{
        if (mcbsp->pdata->buffer_size)
                sysfs_remove_group(&mcbsp->dev->kobj, &additional_attr_group);

        if (mcbsp->st_data) {
                sysfs_remove_group(&mcbsp->dev->kobj, &sidetone_attr_group);
                clk_put(mcbsp->st_data->mcbsp_iclk);
        }
}