/*
 * drivers/dma/imx-sdma.c
 *
 * This file contains a driver for the Freescale Smart DMA engine
 *
 * Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
 *
 * Based on code from Freescale:
 *
 * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/semaphore.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/firmware.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/dmaengine.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>

#include <asm/irq.h>
#include <linux/platform_data/dma-imx-sdma.h>
#include <linux/platform_data/dma-imx.h>

#include "dmaengine.h"

/* SDMA registers */
#define SDMA_H_C0PTR            0x000
#define SDMA_H_INTR             0x004
#define SDMA_H_STATSTOP         0x008
#define SDMA_H_START            0x00c
#define SDMA_H_EVTOVR           0x010
#define SDMA_H_DSPOVR           0x014
#define SDMA_H_HOSTOVR          0x018
#define SDMA_H_EVTPEND          0x01c
#define SDMA_H_DSPENBL          0x020
#define SDMA_H_RESET            0x024
#define SDMA_H_EVTERR           0x028
#define SDMA_H_INTRMSK          0x02c
#define SDMA_H_PSW              0x030
#define SDMA_H_EVTERRDBG        0x034
#define SDMA_H_CONFIG           0x038
#define SDMA_ONCE_ENB           0x040
#define SDMA_ONCE_DATA          0x044
#define SDMA_ONCE_INSTR         0x048
#define SDMA_ONCE_STAT          0x04c
#define SDMA_ONCE_CMD           0x050
#define SDMA_EVT_MIRROR         0x054
#define SDMA_ILLINSTADDR        0x058
#define SDMA_CHN0ADDR           0x05c
#define SDMA_ONCE_RTB           0x060
#define SDMA_XTRIG_CONF1        0x070
#define SDMA_XTRIG_CONF2        0x074
#define SDMA_CHNENBL0_IMX35     0x200
#define SDMA_CHNENBL0_IMX31     0x080
#define SDMA_CHNPRI_0           0x100

/*
 * Buffer descriptor status values.
 */
#define BD_DONE  0x01
#define BD_WRAP  0x02
#define BD_CONT  0x04
#define BD_INTR  0x08
#define BD_RROR  0x10
#define BD_LAST  0x20
#define BD_EXTD  0x80

/*
 * Data Node descriptor status values.
 */
#define DND_END_OF_FRAME  0x80
#define DND_END_OF_XFER   0x40
#define DND_DONE          0x20
#define DND_UNUSED        0x01

/*
 * IPCV2 descriptor status values.
 */
#define BD_IPCV2_END_OF_FRAME  0x40

#define IPCV2_MAX_NODES        50
/*
 * Error bit set in the CCB status field by the SDMA,
 * in setbd routine, in case of a transfer error
 */
#define DATA_ERROR  0x10000000

/*
 * Buffer descriptor commands.
 */
#define C0_ADDR             0x01
#define C0_LOAD             0x02
#define C0_DUMP             0x03
#define C0_SETCTX           0x07
#define C0_GETCTX           0x03
#define C0_SETDM            0x01
#define C0_SETPM            0x04
#define C0_GETDM            0x02
#define C0_GETPM            0x08
/*
 * Change endianness indicator in the BD command field
 */
#define CHANGE_ENDIANNESS   0x80

/*
 * Mode/Count of data node descriptors - IPCv2
 */
struct sdma_mode_count {
        u32 count   : 16; /* size of the buffer pointed by this BD */
        u32 status  :  8; /* E,R,I,C,W,D status bits stored here */
        u32 command :  8; /* command mostlky used for channel 0 */
};

/*
 * Buffer descriptor
 */
struct sdma_buffer_descriptor {
        struct sdma_mode_count  mode;
        u32 buffer_addr;        /* address of the buffer described */
        u32 ext_buffer_addr;    /* extended buffer address */
} __attribute__ ((packed));

/**
 * struct sdma_channel_control - Channel control Block
 *
 * @current_bd_ptr      current buffer descriptor processed
 * @base_bd_ptr         first element of buffer descriptor array
 * @unused              padding. The SDMA engine expects an array of 128 byte
 *                      control blocks
 */
struct sdma_channel_control {
        u32 current_bd_ptr;
        u32 base_bd_ptr;
        u32 unused[2];
} __attribute__ ((packed));

/**
 * struct sdma_state_registers - SDMA context for a channel
 *
 * @pc:         program counter
 * @t:          test bit: status of arithmetic & test instruction
 * @rpc:        return program counter
 * @sf:         source fault while loading data
 * @spc:        loop start program counter
 * @df:         destination fault while storing data
 * @epc:        loop end program counter
 * @lm:         loop mode
 */
struct sdma_state_registers {
        u32 pc     :14;
        u32 unused1: 1;
        u32 t      : 1;
        u32 rpc    :14;
        u32 unused0: 1;
        u32 sf     : 1;
        u32 spc    :14;
        u32 unused2: 1;
        u32 df     : 1;
        u32 epc    :14;
        u32 lm     : 2;
} __attribute__ ((packed));

/**
 * struct sdma_context_data - sdma context specific to a channel
 *
 * @channel_state:      channel state bits
 * @gReg:               general registers
 * @mda:                burst dma destination address register
 * @msa:                burst dma source address register
 * @ms:                 burst dma status register
 * @md:                 burst dma data register
 * @pda:                peripheral dma destination address register
 * @psa:                peripheral dma source address register
 * @ps:                 peripheral dma status register
 * @pd:                 peripheral dma data register
 * @ca:                 CRC polynomial register
 * @cs:                 CRC accumulator register
 * @dda:                dedicated core destination address register
 * @dsa:                dedicated core source address register
 * @ds:                 dedicated core status register
 * @dd:                 dedicated core data register
 */
struct sdma_context_data {
        struct sdma_state_registers  channel_state;
        u32  gReg[8];
        u32  mda;
        u32  msa;
        u32  ms;
        u32  md;
        u32  pda;
        u32  psa;
        u32  ps;
        u32  pd;
        u32  ca;
        u32  cs;
        u32  dda;
        u32  dsa;
        u32  ds;
        u32  dd;
        u32  scratch0;
        u32  scratch1;
        u32  scratch2;
        u32  scratch3;
        u32  scratch4;
        u32  scratch5;
        u32  scratch6;
        u32  scratch7;
} __attribute__ ((packed));

#define NUM_BD (int)(PAGE_SIZE / sizeof(struct sdma_buffer_descriptor))

struct sdma_engine;

/**
 * struct sdma_channel - housekeeping for a SDMA channel
 *
 * @sdma                pointer to the SDMA engine for this channel
 * @channel             the channel number, matches dmaengine chan_id + 1
 * @direction           transfer type. Needed for setting SDMA script
 * @peripheral_type     Peripheral type. Needed for setting SDMA script
 * @event_id0           aka dma request line
 * @event_id1           for channels that use 2 events
 * @word_size           peripheral access size
 * @buf_tail            ID of the buffer that was processed
 * @num_bd              max NUM_BD. number of descriptors currently handling
 */
struct sdma_channel {
        struct sdma_engine              *sdma;
        unsigned int                    channel;
        enum dma_transfer_direction             direction;
        enum sdma_peripheral_type       peripheral_type;
        unsigned int                    event_id0;
        unsigned int                    event_id1;
        enum dma_slave_buswidth         word_size;
        unsigned int                    buf_tail;
        unsigned int                    num_bd;
        unsigned int                    period_len;
        struct sdma_buffer_descriptor   *bd;
        dma_addr_t                      bd_phys;
        unsigned int                    pc_from_device, pc_to_device;
        unsigned long                   flags;
        dma_addr_t                      per_address;
        unsigned long                   event_mask[2];
        unsigned long                   watermark_level;
        u32                             shp_addr, per_addr;
        struct dma_chan                 chan;
        spinlock_t                      lock;
        struct dma_async_tx_descriptor  desc;
        enum dma_status                 status;
        unsigned int                    chn_count;
        unsigned int                    chn_real_count;
        struct tasklet_struct           tasklet;
        struct imx_dma_data             data;
};

#define IMX_DMA_SG_LOOP         BIT(0)

#define MAX_DMA_CHANNELS 32
#define MXC_SDMA_DEFAULT_PRIORITY 1
#define MXC_SDMA_MIN_PRIORITY 1
#define MXC_SDMA_MAX_PRIORITY 7

#define SDMA_FIRMWARE_MAGIC 0x414d4453

/**
 * struct sdma_firmware_header - Layout of the firmware image
 *
 * @magic               "SDMA"
 * @version_major       increased whenever layout of struct sdma_script_start_addrs
 *                      changes.
 * @version_minor       firmware minor version (for binary compatible changes)
 * @script_addrs_start  offset of struct sdma_script_start_addrs in this image
 * @num_script_addrs    Number of script addresses in this image
 * @ram_code_start      offset of SDMA ram image in this firmware image
 * @ram_code_size       size of SDMA ram image
 * @script_addrs        Stores the start address of the SDMA scripts
 *                      (in SDMA memory space)
 */
struct sdma_firmware_header {
        u32     magic;
        u32     version_major;
        u32     version_minor;
        u32     script_addrs_start;
        u32     num_script_addrs;
        u32     ram_code_start;
        u32     ram_code_size;
};

struct sdma_driver_data {
        int chnenbl0;
        int num_events;
        struct sdma_script_start_addrs  *script_addrs;
};

struct sdma_engine {
        struct device                   *dev;
        struct device_dma_parameters    dma_parms;
        struct sdma_channel             channel[MAX_DMA_CHANNELS];
        struct sdma_channel_control     *channel_control;
        void __iomem                    *regs;
        struct sdma_context_data        *context;
        dma_addr_t                      context_phys;
        struct dma_device               dma_device;
        struct clk                      *clk_ipg;
        struct clk                      *clk_ahb;
        spinlock_t                      channel_0_lock;
        u32                             script_number;
        struct sdma_script_start_addrs  *script_addrs;
        const struct sdma_driver_data   *drvdata;
};

static struct sdma_driver_data sdma_imx31 = {
        .chnenbl0 = SDMA_CHNENBL0_IMX31,
        .num_events = 32,
};

static struct sdma_script_start_addrs sdma_script_imx25 = {
        .ap_2_ap_addr = 729,
        .uart_2_mcu_addr = 904,
        .per_2_app_addr = 1255,
        .mcu_2_app_addr = 834,
        .uartsh_2_mcu_addr = 1120,
        .per_2_shp_addr = 1329,
        .mcu_2_shp_addr = 1048,
        .ata_2_mcu_addr = 1560,
        .mcu_2_ata_addr = 1479,
        .app_2_per_addr = 1189,
        .app_2_mcu_addr = 770,
        .shp_2_per_addr = 1407,
        .shp_2_mcu_addr = 979,
};

static struct sdma_driver_data sdma_imx25 = {
        .chnenbl0 = SDMA_CHNENBL0_IMX35,
        .num_events = 48,
        .script_addrs = &sdma_script_imx25,
};

static struct sdma_driver_data sdma_imx35 = {
        .chnenbl0 = SDMA_CHNENBL0_IMX35,
        .num_events = 48,
};

static struct sdma_script_start_addrs sdma_script_imx51 = {
        .ap_2_ap_addr = 642,
        .uart_2_mcu_addr = 817,
        .mcu_2_app_addr = 747,
        .mcu_2_shp_addr = 961,
        .ata_2_mcu_addr = 1473,
        .mcu_2_ata_addr = 1392,
        .app_2_per_addr = 1033,
        .app_2_mcu_addr = 683,
        .shp_2_per_addr = 1251,
        .shp_2_mcu_addr = 892,
};

static struct sdma_driver_data sdma_imx51 = {
        .chnenbl0 = SDMA_CHNENBL0_IMX35,
        .num_events = 48,
        .script_addrs = &sdma_script_imx51,
};

static struct sdma_script_start_addrs sdma_script_imx53 = {
        .ap_2_ap_addr = 642,
        .app_2_mcu_addr = 683,
        .mcu_2_app_addr = 747,
        .uart_2_mcu_addr = 817,
        .shp_2_mcu_addr = 891,
        .mcu_2_shp_addr = 960,
        .uartsh_2_mcu_addr = 1032,
        .spdif_2_mcu_addr = 1100,
        .mcu_2_spdif_addr = 1134,
        .firi_2_mcu_addr = 1193,
        .mcu_2_firi_addr = 1290,
};

static struct sdma_driver_data sdma_imx53 = {
        .chnenbl0 = SDMA_CHNENBL0_IMX35,
        .num_events = 48,
        .script_addrs = &sdma_script_imx53,
};

static struct sdma_script_start_addrs sdma_script_imx6q = {
        .ap_2_ap_addr = 642,
        .uart_2_mcu_addr = 817,
        .mcu_2_app_addr = 747,
        .per_2_per_addr = 6331,
        .uartsh_2_mcu_addr = 1032,
        .mcu_2_shp_addr = 960,
        .app_2_mcu_addr = 683,
        .shp_2_mcu_addr = 891,
        .spdif_2_mcu_addr = 1100,
        .mcu_2_spdif_addr = 1134,
};

static struct sdma_driver_data sdma_imx6q = {
        .chnenbl0 = SDMA_CHNENBL0_IMX35,
        .num_events = 48,
        .script_addrs = &sdma_script_imx6q,
};

static struct platform_device_id sdma_devtypes[] = {
        {
                .name = "imx25-sdma",
                .driver_data = (unsigned long)&sdma_imx25,
        }, {
                .name = "imx31-sdma",
                .driver_data = (unsigned long)&sdma_imx31,
        }, {
                .name = "imx35-sdma",
                .driver_data = (unsigned long)&sdma_imx35,
        }, {
                .name = "imx51-sdma",
                .driver_data = (unsigned long)&sdma_imx51,
        }, {
                .name = "imx53-sdma",
                .driver_data = (unsigned long)&sdma_imx53,
        }, {
                .name = "imx6q-sdma",
                .driver_data = (unsigned long)&sdma_imx6q,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(platform, sdma_devtypes);

static const struct of_device_id sdma_dt_ids[] = {
        { .compatible = "fsl,imx6q-sdma", .data = &sdma_imx6q, },
        { .compatible = "fsl,imx53-sdma", .data = &sdma_imx53, },
        { .compatible = "fsl,imx51-sdma", .data = &sdma_imx51, },
        { .compatible = "fsl,imx35-sdma", .data = &sdma_imx35, },
        { .compatible = "fsl,imx31-sdma", .data = &sdma_imx31, },
        { .compatible = "fsl,imx25-sdma", .data = &sdma_imx25, },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sdma_dt_ids);

#define SDMA_H_CONFIG_DSPDMA    BIT(12) /* indicates if the DSPDMA is used */
#define SDMA_H_CONFIG_RTD_PINS  BIT(11) /* indicates if Real-Time Debug pins are enabled */
#define SDMA_H_CONFIG_ACR       BIT(4)  /* indicates if AHB freq /core freq = 2 or 1 */
#define SDMA_H_CONFIG_CSM       (3)       /* indicates which context switch mode is selected*/

static inline u32 chnenbl_ofs(struct sdma_engine *sdma, unsigned int event)
{
        u32 chnenbl0 = sdma->drvdata->chnenbl0;
        return chnenbl0 + event * 4;
}

static int sdma_config_ownership(struct sdma_channel *sdmac,
                bool event_override, bool mcu_override, bool dsp_override)
{
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;
        unsigned long evt, mcu, dsp;

        if (event_override && mcu_override && dsp_override)
                return -EINVAL;

        evt = readl_relaxed(sdma->regs + SDMA_H_EVTOVR);
        mcu = readl_relaxed(sdma->regs + SDMA_H_HOSTOVR);
        dsp = readl_relaxed(sdma->regs + SDMA_H_DSPOVR);

        if (dsp_override)
                __clear_bit(channel, &dsp);
        else
                __set_bit(channel, &dsp);

        if (event_override)
                __clear_bit(channel, &evt);
        else
                __set_bit(channel, &evt);

        if (mcu_override)
                __clear_bit(channel, &mcu);
        else
                __set_bit(channel, &mcu);

        writel_relaxed(evt, sdma->regs + SDMA_H_EVTOVR);
        writel_relaxed(mcu, sdma->regs + SDMA_H_HOSTOVR);
        writel_relaxed(dsp, sdma->regs + SDMA_H_DSPOVR);

        return 0;
}

static void sdma_enable_channel(struct sdma_engine *sdma, int channel)
{
        writel(BIT(channel), sdma->regs + SDMA_H_START);
}

/*
 * sdma_run_channel0 - run a channel and wait till it's done
 */
static int sdma_run_channel0(struct sdma_engine *sdma)
{
        int ret;
        unsigned long timeout = 500;

        sdma_enable_channel(sdma, 0);

        while (!(ret = readl_relaxed(sdma->regs + SDMA_H_INTR) & 1)) {
                if (timeout-- <= 0)
                        break;
                udelay(1);
        }

        if (ret) {
                /* Clear the interrupt status */
                writel_relaxed(ret, sdma->regs + SDMA_H_INTR);
        } else {
                dev_err(sdma->dev, "Timeout waiting for CH0 ready\n");
        }

        /* Set bits of CONFIG register with dynamic context switching */
        if (readl(sdma->regs + SDMA_H_CONFIG) == 0)
                writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs + SDMA_H_CONFIG);

        return ret ? 0 : -ETIMEDOUT;
}

static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
                u32 address)
{
        struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd;
        void *buf_virt;
        dma_addr_t buf_phys;
        int ret;
        unsigned long flags;

        buf_virt = dma_alloc_coherent(NULL,
                        size,
                        &buf_phys, GFP_KERNEL);
        if (!buf_virt) {
                return -ENOMEM;
        }

        spin_lock_irqsave(&sdma->channel_0_lock, flags);

        bd0->mode.command = C0_SETPM;
        bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
        bd0->mode.count = size / 2;
        bd0->buffer_addr = buf_phys;
        bd0->ext_buffer_addr = address;

        memcpy(buf_virt, buf, size);

        ret = sdma_run_channel0(sdma);

        spin_unlock_irqrestore(&sdma->channel_0_lock, flags);

        dma_free_coherent(NULL, size, buf_virt, buf_phys);

        return ret;
}

static void sdma_event_enable(struct sdma_channel *sdmac, unsigned int event)
{
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;
        unsigned long val;
        u32 chnenbl = chnenbl_ofs(sdma, event);

        val = readl_relaxed(sdma->regs + chnenbl);
        __set_bit(channel, &val);
        writel_relaxed(val, sdma->regs + chnenbl);
}

static void sdma_event_disable(struct sdma_channel *sdmac, unsigned int event)
{
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;
        u32 chnenbl = chnenbl_ofs(sdma, event);
        unsigned long val;

        val = readl_relaxed(sdma->regs + chnenbl);
        __clear_bit(channel, &val);
        writel_relaxed(val, sdma->regs + chnenbl);
}

static void sdma_handle_channel_loop(struct sdma_channel *sdmac)
{
        if (sdmac->desc.callback)
                sdmac->desc.callback(sdmac->desc.callback_param);
}

static void sdma_update_channel_loop(struct sdma_channel *sdmac)
{
        struct sdma_buffer_descriptor *bd;

        /*
         * loop mode. Iterate over descriptors, re-setup them and
         * call callback function.
         */
        while (1) {
                bd = &sdmac->bd[sdmac->buf_tail];

                if (bd->mode.status & BD_DONE)
                        break;

                if (bd->mode.status & BD_RROR)
                        sdmac->status = DMA_ERROR;

                bd->mode.status |= BD_DONE;
                sdmac->buf_tail++;
                sdmac->buf_tail %= sdmac->num_bd;
        }
}

static void mxc_sdma_handle_channel_normal(struct sdma_channel *sdmac)
{
        struct sdma_buffer_descriptor *bd;
        int i, error = 0;

        sdmac->chn_real_count = 0;
        /*
         * non loop mode. Iterate over all descriptors, collect
         * errors and call callback function
         */
        for (i = 0; i < sdmac->num_bd; i++) {
                bd = &sdmac->bd[i];

                 if (bd->mode.status & (BD_DONE | BD_RROR))
                        error = -EIO;
                 sdmac->chn_real_count += bd->mode.count;
        }

        if (error)
                sdmac->status = DMA_ERROR;
        else
                sdmac->status = DMA_COMPLETE;

        dma_cookie_complete(&sdmac->desc);
        if (sdmac->desc.callback)
                sdmac->desc.callback(sdmac->desc.callback_param);
}

static void sdma_tasklet(unsigned long data)
{
        struct sdma_channel *sdmac = (struct sdma_channel *) data;

        if (sdmac->flags & IMX_DMA_SG_LOOP)
                sdma_handle_channel_loop(sdmac);
        else
                mxc_sdma_handle_channel_normal(sdmac);
}

static irqreturn_t sdma_int_handler(int irq, void *dev_id)
{
        struct sdma_engine *sdma = dev_id;
        unsigned long stat;

        stat = readl_relaxed(sdma->regs + SDMA_H_INTR);
        /* not interested in channel 0 interrupts */
        stat &= ~1;
        writel_relaxed(stat, sdma->regs + SDMA_H_INTR);

        while (stat) {
                int channel = fls(stat) - 1;
                struct sdma_channel *sdmac = &sdma->channel[channel];

                if (sdmac->flags & IMX_DMA_SG_LOOP)
                        sdma_update_channel_loop(sdmac);

                tasklet_schedule(&sdmac->tasklet);

                __clear_bit(channel, &stat);
        }

        return IRQ_HANDLED;
}

/*
 * sets the pc of SDMA script according to the peripheral type
 */
static void sdma_get_pc(struct sdma_channel *sdmac,
                enum sdma_peripheral_type peripheral_type)
{
        struct sdma_engine *sdma = sdmac->sdma;
        int per_2_emi = 0, emi_2_per = 0;
        /*
         * These are needed once we start to support transfers between
         * two peripherals or memory-to-memory transfers
         */
        int per_2_per = 0, emi_2_emi = 0;

        sdmac->pc_from_device = 0;
        sdmac->pc_to_device = 0;

        switch (peripheral_type) {
        case IMX_DMATYPE_MEMORY:
                emi_2_emi = sdma->script_addrs->ap_2_ap_addr;
                break;
        case IMX_DMATYPE_DSP:
                emi_2_per = sdma->script_addrs->bp_2_ap_addr;
                per_2_emi = sdma->script_addrs->ap_2_bp_addr;
                break;
        case IMX_DMATYPE_FIRI:
                per_2_emi = sdma->script_addrs->firi_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_firi_addr;
                break;
        case IMX_DMATYPE_UART:
                per_2_emi = sdma->script_addrs->uart_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_app_addr;
                break;
        case IMX_DMATYPE_UART_SP:
                per_2_emi = sdma->script_addrs->uartsh_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_shp_addr;
                break;
        case IMX_DMATYPE_ATA:
                per_2_emi = sdma->script_addrs->ata_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_ata_addr;
                break;
        case IMX_DMATYPE_CSPI:
        case IMX_DMATYPE_EXT:
        case IMX_DMATYPE_SSI:
        case IMX_DMATYPE_SAI:
                per_2_emi = sdma->script_addrs->app_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_app_addr;
                break;
        case IMX_DMATYPE_SSI_DUAL:
                per_2_emi = sdma->script_addrs->ssish_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_ssish_addr;
                break;
        case IMX_DMATYPE_SSI_SP:
        case IMX_DMATYPE_MMC:
        case IMX_DMATYPE_SDHC:
        case IMX_DMATYPE_CSPI_SP:
        case IMX_DMATYPE_ESAI:
        case IMX_DMATYPE_MSHC_SP:
                per_2_emi = sdma->script_addrs->shp_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_shp_addr;
                break;
        case IMX_DMATYPE_ASRC:
                per_2_emi = sdma->script_addrs->asrc_2_mcu_addr;
                emi_2_per = sdma->script_addrs->asrc_2_mcu_addr;
                per_2_per = sdma->script_addrs->per_2_per_addr;
                break;
        case IMX_DMATYPE_ASRC_SP:
                per_2_emi = sdma->script_addrs->shp_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_shp_addr;
                per_2_per = sdma->script_addrs->per_2_per_addr;
                break;
        case IMX_DMATYPE_MSHC:
                per_2_emi = sdma->script_addrs->mshc_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_mshc_addr;
                break;
        case IMX_DMATYPE_CCM:
                per_2_emi = sdma->script_addrs->dptc_dvfs_addr;
                break;
        case IMX_DMATYPE_SPDIF:
                per_2_emi = sdma->script_addrs->spdif_2_mcu_addr;
                emi_2_per = sdma->script_addrs->mcu_2_spdif_addr;
                break;
        case IMX_DMATYPE_IPU_MEMORY:
                emi_2_per = sdma->script_addrs->ext_mem_2_ipu_addr;
                break;
        default:
                break;
        }

        sdmac->pc_from_device = per_2_emi;
        sdmac->pc_to_device = emi_2_per;
}

static int sdma_load_context(struct sdma_channel *sdmac)
{
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;
        int load_address;
        struct sdma_context_data *context = sdma->context;
        struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd;
        int ret;
        unsigned long flags;

        if (sdmac->direction == DMA_DEV_TO_MEM) {
                load_address = sdmac->pc_from_device;
        } else {
                load_address = sdmac->pc_to_device;
        }

        if (load_address < 0)
                return load_address;

        dev_dbg(sdma->dev, "load_address = %d\n", load_address);
        dev_dbg(sdma->dev, "wml = 0x%08x\n", (u32)sdmac->watermark_level);
        dev_dbg(sdma->dev, "shp_addr = 0x%08x\n", sdmac->shp_addr);
        dev_dbg(sdma->dev, "per_addr = 0x%08x\n", sdmac->per_addr);
        dev_dbg(sdma->dev, "event_mask0 = 0x%08x\n", (u32)sdmac->event_mask[0]);
        dev_dbg(sdma->dev, "event_mask1 = 0x%08x\n", (u32)sdmac->event_mask[1]);

        spin_lock_irqsave(&sdma->channel_0_lock, flags);

        memset(context, 0, sizeof(*context));
        context->channel_state.pc = load_address;

        /* Send by context the event mask,base address for peripheral
         * and watermark level
         */
        context->gReg[0] = sdmac->event_mask[1];
        context->gReg[1] = sdmac->event_mask[0];
        context->gReg[2] = sdmac->per_addr;
        context->gReg[6] = sdmac->shp_addr;
        context->gReg[7] = sdmac->watermark_level;

        bd0->mode.command = C0_SETDM;
        bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
        bd0->mode.count = sizeof(*context) / 4;
        bd0->buffer_addr = sdma->context_phys;
        bd0->ext_buffer_addr = 2048 + (sizeof(*context) / 4) * channel;
        ret = sdma_run_channel0(sdma);

        spin_unlock_irqrestore(&sdma->channel_0_lock, flags);

        return ret;
}

static struct sdma_channel *to_sdma_chan(struct dma_chan *chan)
{
        return container_of(chan, struct sdma_channel, chan);
}

static int sdma_disable_channel(struct dma_chan *chan)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;

        writel_relaxed(BIT(channel), sdma->regs + SDMA_H_STATSTOP);
        sdmac->status = DMA_ERROR;

        return 0;
}

static int sdma_config_channel(struct dma_chan *chan)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        int ret;

        sdma_disable_channel(chan);

        sdmac->event_mask[0] = 0;
        sdmac->event_mask[1] = 0;
        sdmac->shp_addr = 0;
        sdmac->per_addr = 0;

        if (sdmac->event_id0) {
                if (sdmac->event_id0 >= sdmac->sdma->drvdata->num_events)
                        return -EINVAL;
                sdma_event_enable(sdmac, sdmac->event_id0);
        }

        switch (sdmac->peripheral_type) {
        case IMX_DMATYPE_DSP:
                sdma_config_ownership(sdmac, false, true, true);
                break;
        case IMX_DMATYPE_MEMORY:
                sdma_config_ownership(sdmac, false, true, false);
                break;
        default:
                sdma_config_ownership(sdmac, true, true, false);
                break;
        }

        sdma_get_pc(sdmac, sdmac->peripheral_type);

        if ((sdmac->peripheral_type != IMX_DMATYPE_MEMORY) &&
                        (sdmac->peripheral_type != IMX_DMATYPE_DSP)) {
                /* Handle multiple event channels differently */
                if (sdmac->event_id1) {
                        sdmac->event_mask[1] = BIT(sdmac->event_id1 % 32);
                        if (sdmac->event_id1 > 31)
                                __set_bit(31, &sdmac->watermark_level);
                        sdmac->event_mask[0] = BIT(sdmac->event_id0 % 32);
                        if (sdmac->event_id0 > 31)
                                __set_bit(30, &sdmac->watermark_level);
                } else {
                        __set_bit(sdmac->event_id0, sdmac->event_mask);
                }
                /* Watermark Level */
                sdmac->watermark_level |= sdmac->watermark_level;
                /* Address */
                sdmac->shp_addr = sdmac->per_address;
        } else {
                sdmac->watermark_level = 0; /* FIXME: M3_BASE_ADDRESS */
        }

        ret = sdma_load_context(sdmac);

        return ret;
}

static int sdma_set_channel_priority(struct sdma_channel *sdmac,
                unsigned int priority)
{
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;

        if (priority < MXC_SDMA_MIN_PRIORITY
            || priority > MXC_SDMA_MAX_PRIORITY) {
                return -EINVAL;
        }

        writel_relaxed(priority, sdma->regs + SDMA_CHNPRI_0 + 4 * channel);

        return 0;
}

static int sdma_request_channel(struct sdma_channel *sdmac)
{
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;
        int ret = -EBUSY;

        sdmac->bd = dma_zalloc_coherent(NULL, PAGE_SIZE, &sdmac->bd_phys,
                                        GFP_KERNEL);
        if (!sdmac->bd) {
                ret = -ENOMEM;
                goto out;
        }

        sdma->channel_control[channel].base_bd_ptr = sdmac->bd_phys;
        sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;

        sdma_set_channel_priority(sdmac, MXC_SDMA_DEFAULT_PRIORITY);
        return 0;
out:

        return ret;
}

static dma_cookie_t sdma_tx_submit(struct dma_async_tx_descriptor *tx)
{
        unsigned long flags;
        struct sdma_channel *sdmac = to_sdma_chan(tx->chan);
        dma_cookie_t cookie;

        spin_lock_irqsave(&sdmac->lock, flags);

        cookie = dma_cookie_assign(tx);

        spin_unlock_irqrestore(&sdmac->lock, flags);

        return cookie;
}

static int sdma_alloc_chan_resources(struct dma_chan *chan)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct imx_dma_data *data = chan->private;
        int prio, ret;

        if (!data)
                return -EINVAL;

        switch (data->priority) {
        case DMA_PRIO_HIGH:
                prio = 3;
                break;
        case DMA_PRIO_MEDIUM:
                prio = 2;
                break;
        case DMA_PRIO_LOW:
        default:
                prio = 1;
                break;
        }

        sdmac->peripheral_type = data->peripheral_type;
        sdmac->event_id0 = data->dma_request;

        clk_enable(sdmac->sdma->clk_ipg);
        clk_enable(sdmac->sdma->clk_ahb);

        ret = sdma_request_channel(sdmac);
        if (ret)
                return ret;

        ret = sdma_set_channel_priority(sdmac, prio);
        if (ret)
                return ret;

        dma_async_tx_descriptor_init(&sdmac->desc, chan);
        sdmac->desc.tx_submit = sdma_tx_submit;
        /* txd.flags will be overwritten in prep funcs */
        sdmac->desc.flags = DMA_CTRL_ACK;

        return 0;
}

static void sdma_free_chan_resources(struct dma_chan *chan)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;

        sdma_disable_channel(chan);

        if (sdmac->event_id0)
                sdma_event_disable(sdmac, sdmac->event_id0);
        if (sdmac->event_id1)
                sdma_event_disable(sdmac, sdmac->event_id1);

        sdmac->event_id0 = 0;
        sdmac->event_id1 = 0;

        sdma_set_channel_priority(sdmac, 0);

        dma_free_coherent(NULL, PAGE_SIZE, sdmac->bd, sdmac->bd_phys);

        clk_disable(sdma->clk_ipg);
        clk_disable(sdma->clk_ahb);
}

static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
                struct dma_chan *chan, struct scatterlist *sgl,
                unsigned int sg_len, enum dma_transfer_direction direction,
                unsigned long flags, void *context)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;
        int ret, i, count;
        int channel = sdmac->channel;
        struct scatterlist *sg;

        if (sdmac->status == DMA_IN_PROGRESS)
                return NULL;
        sdmac->status = DMA_IN_PROGRESS;

        sdmac->flags = 0;

        sdmac->buf_tail = 0;

        dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",
                        sg_len, channel);

        sdmac->direction = direction;
        ret = sdma_load_context(sdmac);
        if (ret)
                goto err_out;

        if (sg_len > NUM_BD) {
                dev_err(sdma->dev, "SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
                                channel, sg_len, NUM_BD);
                ret = -EINVAL;
                goto err_out;
        }

        sdmac->chn_count = 0;
        for_each_sg(sgl, sg, sg_len, i) {
                struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
                int param;

                bd->buffer_addr = sg->dma_address;

                count = sg_dma_len(sg);

                if (count > 0xffff) {
                        dev_err(sdma->dev, "SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n",
                                        channel, count, 0xffff);
                        ret = -EINVAL;
                        goto err_out;
                }

                bd->mode.count = count;
                sdmac->chn_count += count;

                if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES) {
                        ret =  -EINVAL;
                        goto err_out;
                }

                switch (sdmac->word_size) {
                case DMA_SLAVE_BUSWIDTH_4_BYTES:
                        bd->mode.command = 0;
                        if (count & 3 || sg->dma_address & 3)
                                return NULL;
                        break;
                case DMA_SLAVE_BUSWIDTH_2_BYTES:
                        bd->mode.command = 2;
                        if (count & 1 || sg->dma_address & 1)
                                return NULL;
                        break;
                case DMA_SLAVE_BUSWIDTH_1_BYTE:
                        bd->mode.command = 1;
                        break;
                default:
                        return NULL;
                }

                param = BD_DONE | BD_EXTD | BD_CONT;

                if (i + 1 == sg_len) {
                        param |= BD_INTR;
                        param |= BD_LAST;
                        param &= ~BD_CONT;
                }

                dev_dbg(sdma->dev, "entry %d: count: %d dma: %#llx %s%s\n",
                                i, count, (u64)sg->dma_address,
                                param & BD_WRAP ? "wrap" : "",
                                param & BD_INTR ? " intr" : "");

                bd->mode.status = param;
        }

        sdmac->num_bd = sg_len;
        sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;

        return &sdmac->desc;
err_out:
        sdmac->status = DMA_ERROR;
        return NULL;
}

static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
                struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
                size_t period_len, enum dma_transfer_direction direction,
                unsigned long flags)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;
        int num_periods = buf_len / period_len;
        int channel = sdmac->channel;
        int ret, i = 0, buf = 0;

        dev_dbg(sdma->dev, "%s channel: %d\n", __func__, channel);

        if (sdmac->status == DMA_IN_PROGRESS)
                return NULL;

        sdmac->status = DMA_IN_PROGRESS;

        sdmac->buf_tail = 0;
        sdmac->period_len = period_len;

        sdmac->flags |= IMX_DMA_SG_LOOP;
        sdmac->direction = direction;
        ret = sdma_load_context(sdmac);
        if (ret)
                goto err_out;

        if (num_periods > NUM_BD) {
                dev_err(sdma->dev, "SDMA channel %d: maximum number of sg exceeded: %d > %d\n",
                                channel, num_periods, NUM_BD);
                goto err_out;
        }

        if (period_len > 0xffff) {
                dev_err(sdma->dev, "SDMA channel %d: maximum period size exceeded: %d > %d\n",
                                channel, period_len, 0xffff);
                goto err_out;
        }

        while (buf < buf_len) {
                struct sdma_buffer_descriptor *bd = &sdmac->bd[i];
                int param;

                bd->buffer_addr = dma_addr;

                bd->mode.count = period_len;

                if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES)
                        goto err_out;
                if (sdmac->word_size == DMA_SLAVE_BUSWIDTH_4_BYTES)
                        bd->mode.command = 0;
                else
                        bd->mode.command = sdmac->word_size;

                param = BD_DONE | BD_EXTD | BD_CONT | BD_INTR;
                if (i + 1 == num_periods)
                        param |= BD_WRAP;

                dev_dbg(sdma->dev, "entry %d: count: %d dma: %#llx %s%s\n",
                                i, period_len, (u64)dma_addr,
                                param & BD_WRAP ? "wrap" : "",
                                param & BD_INTR ? " intr" : "");

                bd->mode.status = param;

                dma_addr += period_len;
                buf += period_len;

                i++;
        }

        sdmac->num_bd = num_periods;
        sdma->channel_control[channel].current_bd_ptr = sdmac->bd_phys;

        return &sdmac->desc;
err_out:
        sdmac->status = DMA_ERROR;
        return NULL;
}

static int sdma_config(struct dma_chan *chan,
                       struct dma_slave_config *dmaengine_cfg)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);

        if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
                sdmac->per_address = dmaengine_cfg->src_addr;
                sdmac->watermark_level = dmaengine_cfg->src_maxburst *
                        dmaengine_cfg->src_addr_width;
                sdmac->word_size = dmaengine_cfg->src_addr_width;
        } else {
                sdmac->per_address = dmaengine_cfg->dst_addr;
                sdmac->watermark_level = dmaengine_cfg->dst_maxburst *
                        dmaengine_cfg->dst_addr_width;
                sdmac->word_size = dmaengine_cfg->dst_addr_width;
        }
        sdmac->direction = dmaengine_cfg->direction;
        return sdma_config_channel(chan);
}

static enum dma_status sdma_tx_status(struct dma_chan *chan,
                                      dma_cookie_t cookie,
                                      struct dma_tx_state *txstate)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        u32 residue;

        if (sdmac->flags & IMX_DMA_SG_LOOP)
                residue = (sdmac->num_bd - sdmac->buf_tail) * sdmac->period_len;
        else
                residue = sdmac->chn_count - sdmac->chn_real_count;

        dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie,
                         residue);

        return sdmac->status;
}

static void sdma_issue_pending(struct dma_chan *chan)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;

        if (sdmac->status == DMA_IN_PROGRESS)
                sdma_enable_channel(sdma, sdmac->channel);
}

#define SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V1 34
#define SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V2 38

static void sdma_add_scripts(struct sdma_engine *sdma,
                const struct sdma_script_start_addrs *addr)
{
        s32 *addr_arr = (u32 *)addr;
        s32 *saddr_arr = (u32 *)sdma->script_addrs;
        int i;

        /* use the default firmware in ROM if missing external firmware */
        if (!sdma->script_number)
                sdma->script_number = SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V1;

        for (i = 0; i < sdma->script_number; i++)
                if (addr_arr[i] > 0)
                        saddr_arr[i] = addr_arr[i];
}

static void sdma_load_firmware(const struct firmware *fw, void *context)
{
        struct sdma_engine *sdma = context;
        const struct sdma_firmware_header *header;
        const struct sdma_script_start_addrs *addr;
        unsigned short *ram_code;

        if (!fw) {
                dev_info(sdma->dev, "external firmware not found, using ROM firmware\n");
                /* In this case we just use the ROM firmware. */
                return;
        }

        if (fw->size < sizeof(*header))
                goto err_firmware;

        header = (struct sdma_firmware_header *)fw->data;

        if (header->magic != SDMA_FIRMWARE_MAGIC)
                goto err_firmware;
        if (header->ram_code_start + header->ram_code_size > fw->size)
                goto err_firmware;
        switch (header->version_major) {
        case 1:
                sdma->script_number = SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V1;
                break;
        case 2:
                sdma->script_number = SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V2;
                break;
        default:
                dev_err(sdma->dev, "unknown firmware version\n");
                goto err_firmware;
        }

        addr = (void *)header + header->script_addrs_start;
        ram_code = (void *)header + header->ram_code_start;

        clk_enable(sdma->clk_ipg);
        clk_enable(sdma->clk_ahb);
        /* download the RAM image for SDMA */
        sdma_load_script(sdma, ram_code,
                        header->ram_code_size,
                        addr->ram_code_start_addr);
        clk_disable(sdma->clk_ipg);
        clk_disable(sdma->clk_ahb);

        sdma_add_scripts(sdma, addr);

        dev_info(sdma->dev, "loaded firmware %d.%d\n",
                        header->version_major,
                        header->version_minor);

err_firmware:
        release_firmware(fw);
}

static int sdma_get_firmware(struct sdma_engine *sdma,
                const char *fw_name)
{
        int ret;

        ret = request_firmware_nowait(THIS_MODULE,
                        FW_ACTION_HOTPLUG, fw_name, sdma->dev,
                        GFP_KERNEL, sdma, sdma_load_firmware);

        return ret;
}

static int sdma_init(struct sdma_engine *sdma)
{
        int i, ret;
        dma_addr_t ccb_phys;

        clk_enable(sdma->clk_ipg);
        clk_enable(sdma->clk_ahb);

        /* Be sure SDMA has not started yet */
        writel_relaxed(0, sdma->regs + SDMA_H_C0PTR);

        sdma->channel_control = dma_alloc_coherent(NULL,
                        MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control) +
                        sizeof(struct sdma_context_data),
                        &ccb_phys, GFP_KERNEL);

        if (!sdma->channel_control) {
                ret = -ENOMEM;
                goto err_dma_alloc;
        }

        sdma->context = (void *)sdma->channel_control +
                MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control);
        sdma->context_phys = ccb_phys +
                MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control);

        /* Zero-out the CCB structures array just allocated */
        memset(sdma->channel_control, 0,
                        MAX_DMA_CHANNELS * sizeof (struct sdma_channel_control));

        /* disable all channels */
        for (i = 0; i < sdma->drvdata->num_events; i++)
                writel_relaxed(0, sdma->regs + chnenbl_ofs(sdma, i));

        /* All channels have priority 0 */
        for (i = 0; i < MAX_DMA_CHANNELS; i++)
                writel_relaxed(0, sdma->regs + SDMA_CHNPRI_0 + i * 4);

        ret = sdma_request_channel(&sdma->channel[0]);
        if (ret)
                goto err_dma_alloc;

        sdma_config_ownership(&sdma->channel[0], false, true, false);

        /* Set Command Channel (Channel Zero) */
        writel_relaxed(0x4050, sdma->regs + SDMA_CHN0ADDR);

        /* Set bits of CONFIG register but with static context switching */
        /* FIXME: Check whether to set ACR bit depending on clock ratios */
        writel_relaxed(0, sdma->regs + SDMA_H_CONFIG);

        writel_relaxed(ccb_phys, sdma->regs + SDMA_H_C0PTR);

        /* Initializes channel's priorities */
        sdma_set_channel_priority(&sdma->channel[0], 7);

        clk_disable(sdma->clk_ipg);
        clk_disable(sdma->clk_ahb);

        return 0;

err_dma_alloc:
        clk_disable(sdma->clk_ipg);
        clk_disable(sdma->clk_ahb);
        dev_err(sdma->dev, "initialisation failed with %d\n", ret);
        return ret;
}

static bool sdma_filter_fn(struct dma_chan *chan, void *fn_param)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct imx_dma_data *data = fn_param;

        if (!imx_dma_is_general_purpose(chan))
                return false;

        sdmac->data = *data;
        chan->private = &sdmac->data;

        return true;
}

static struct dma_chan *sdma_xlate(struct of_phandle_args *dma_spec,
                                   struct of_dma *ofdma)
{
        struct sdma_engine *sdma = ofdma->of_dma_data;
        dma_cap_mask_t mask = sdma->dma_device.cap_mask;
        struct imx_dma_data data;

        if (dma_spec->args_count != 3)
                return NULL;

        data.dma_request = dma_spec->args[0];
        data.peripheral_type = dma_spec->args[1];
        data.priority = dma_spec->args[2];

        return dma_request_channel(mask, sdma_filter_fn, &data);
}

static int sdma_probe(struct platform_device *pdev)
{
        const struct of_device_id *of_id =
                        of_match_device(sdma_dt_ids, &pdev->dev);
        struct device_node *np = pdev->dev.of_node;
        const char *fw_name;
        int ret;
        int irq;
        struct resource *iores;
        struct sdma_platform_data *pdata = dev_get_platdata(&pdev->dev);
        int i;
        struct sdma_engine *sdma;
        s32 *saddr_arr;
        const struct sdma_driver_data *drvdata = NULL;

        if (of_id)
                drvdata = of_id->data;
        else if (pdev->id_entry)
                drvdata = (void *)pdev->id_entry->driver_data;

        if (!drvdata) {
                dev_err(&pdev->dev, "unable to find driver data\n");
                return -EINVAL;
        }

        ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

        sdma = devm_kzalloc(&pdev->dev, sizeof(*sdma), GFP_KERNEL);
        if (!sdma)
                return -ENOMEM;

        spin_lock_init(&sdma->channel_0_lock);

        sdma->dev = &pdev->dev;
        sdma->drvdata = drvdata;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        sdma->regs = devm_ioremap_resource(&pdev->dev, iores);
        if (IS_ERR(sdma->regs))
                return PTR_ERR(sdma->regs);

        sdma->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
        if (IS_ERR(sdma->clk_ipg))
                return PTR_ERR(sdma->clk_ipg);

        sdma->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
        if (IS_ERR(sdma->clk_ahb))
                return PTR_ERR(sdma->clk_ahb);

        clk_prepare(sdma->clk_ipg);
        clk_prepare(sdma->clk_ahb);

        ret = devm_request_irq(&pdev->dev, irq, sdma_int_handler, 0, "sdma",
                               sdma);
        if (ret)
                return ret;

        sdma->script_addrs = kzalloc(sizeof(*sdma->script_addrs), GFP_KERNEL);
        if (!sdma->script_addrs)
                return -ENOMEM;

        /* initially no scripts available */
        saddr_arr = (s32 *)sdma->script_addrs;
        for (i = 0; i < SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V1; i++)
                saddr_arr[i] = -EINVAL;

        dma_cap_set(DMA_SLAVE, sdma->dma_device.cap_mask);
        dma_cap_set(DMA_CYCLIC, sdma->dma_device.cap_mask);

        INIT_LIST_HEAD(&sdma->dma_device.channels);
        /* Initialize channel parameters */
        for (i = 0; i < MAX_DMA_CHANNELS; i++) {
                struct sdma_channel *sdmac = &sdma->channel[i];

                sdmac->sdma = sdma;
                spin_lock_init(&sdmac->lock);

                sdmac->chan.device = &sdma->dma_device;
                dma_cookie_init(&sdmac->chan);
                sdmac->channel = i;

                tasklet_init(&sdmac->tasklet, sdma_tasklet,
                             (unsigned long) sdmac);
                /*
                 * Add the channel to the DMAC list. Do not add channel 0 though
                 * because we need it internally in the SDMA driver. This also means
                 * that channel 0 in dmaengine counting matches sdma channel 1.
                 */
                if (i)
                        list_add_tail(&sdmac->chan.device_node,
                                        &sdma->dma_device.channels);
        }

        ret = sdma_init(sdma);
        if (ret)
                goto err_init;

        if (sdma->drvdata->script_addrs)
                sdma_add_scripts(sdma, sdma->drvdata->script_addrs);
        if (pdata && pdata->script_addrs)
                sdma_add_scripts(sdma, pdata->script_addrs);

        if (pdata) {
                ret = sdma_get_firmware(sdma, pdata->fw_name);
                if (ret)
                        dev_warn(&pdev->dev, "failed to get firmware from platform data\n");
        } else {
                /*
                 * Because that device tree does not encode ROM script address,
                 * the RAM script in firmware is mandatory for device tree
                 * probe, otherwise it fails.
                 */
                ret = of_property_read_string(np, "fsl,sdma-ram-script-name",
                                              &fw_name);
                if (ret)
                        dev_warn(&pdev->dev, "failed to get firmware name\n");
                else {
                        ret = sdma_get_firmware(sdma, fw_name);
                        if (ret)
                                dev_warn(&pdev->dev, "failed to get firmware from device tree\n");
                }
        }

        sdma->dma_device.dev = &pdev->dev;

        sdma->dma_device.device_alloc_chan_resources = sdma_alloc_chan_resources;
        sdma->dma_device.device_free_chan_resources = sdma_free_chan_resources;
        sdma->dma_device.device_tx_status = sdma_tx_status;
        sdma->dma_device.device_prep_slave_sg = sdma_prep_slave_sg;
        sdma->dma_device.device_prep_dma_cyclic = sdma_prep_dma_cyclic;
        sdma->dma_device.device_config = sdma_config;
        sdma->dma_device.device_terminate_all = sdma_disable_channel;
        sdma->dma_device.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
        sdma->dma_device.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
        sdma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
        sdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
        sdma->dma_device.device_issue_pending = sdma_issue_pending;
        sdma->dma_device.dev->dma_parms = &sdma->dma_parms;
        dma_set_max_seg_size(sdma->dma_device.dev, 65535);

        platform_set_drvdata(pdev, sdma);

        ret = dma_async_device_register(&sdma->dma_device);
        if (ret) {
                dev_err(&pdev->dev, "unable to register\n");
                goto err_init;
        }

        if (np) {
                ret = of_dma_controller_register(np, sdma_xlate, sdma);
                if (ret) {
                        dev_err(&pdev->dev, "failed to register controller\n");
                        goto err_register;
                }
        }

        dev_info(sdma->dev, "initialized\n");

        return 0;

err_register:
        dma_async_device_unregister(&sdma->dma_device);
err_init:
        kfree(sdma->script_addrs);
        return ret;
}

static int sdma_remove(struct platform_device *pdev)
{
        struct sdma_engine *sdma = platform_get_drvdata(pdev);
        int i;

        dma_async_device_unregister(&sdma->dma_device);
        kfree(sdma->script_addrs);
        /* Kill the tasklet */
        for (i = 0; i < MAX_DMA_CHANNELS; i++) {
                struct sdma_channel *sdmac = &sdma->channel[i];

                tasklet_kill(&sdmac->tasklet);
        }

        platform_set_drvdata(pdev, NULL);
        dev_info(&pdev->dev, "Removed...\n");
        return 0;
}

static struct platform_driver sdma_driver = {
        .driver         = {
                .name   = "imx-sdma",
                .of_match_table = sdma_dt_ids,
        },
        .id_table       = sdma_devtypes,
        .remove         = sdma_remove,
        .probe          = sdma_probe,
};

module_platform_driver(sdma_driver);

MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION("i.MX SDMA driver");
MODULE_LICENSE("GPL");