// SPDX-License-Identifier: GPL-2.0+
//
// 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.

#include <linux/init.h>
#include <linux/iopoll.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_address.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/workqueue.h>

#include <asm/irq.h>
#include <linux/platform_data/dma-imx-sdma.h>
#include <linux/platform_data/dma-imx.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>

#include "dmaengine.h"
#include "virt-dma.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

/*
 *  p_2_p watermark_level description
 *      Bits            Name                    Description
 *      0-7             Lower WML               Lower watermark level
 *      8               PS                      1: Pad Swallowing
 *                                              0: No Pad Swallowing
 *      9               PA                      1: Pad Adding
 *                                              0: No Pad Adding
 *      10              SPDIF                   If this bit is set both source
 *                                              and destination are on SPBA
 *      11              Source Bit(SP)          1: Source on SPBA
 *                                              0: Source on AIPS
 *      12              Destination Bit(DP)     1: Destination on SPBA
 *                                              0: Destination on AIPS
 *      13-15           ---------               MUST BE 0
 *      16-23           Higher WML              HWML
 *      24-27           N                       Total number of samples after
 *                                              which Pad adding/Swallowing
 *                                              must be done. It must be odd.
 *      28              Lower WML Event(LWE)    SDMA events reg to check for
 *                                              LWML event mask
 *                                              0: LWE in EVENTS register
 *                                              1: LWE in EVENTS2 register
 *      29              Higher WML Event(HWE)   SDMA events reg to check for
 *                                              HWML event mask
 *                                              0: HWE in EVENTS register
 *                                              1: HWE in EVENTS2 register
 *      30              ---------               MUST BE 0
 *      31              CONT                    1: Amount of samples to be
 *                                              transferred is unknown and
 *                                              script will keep on
 *                                              transferring samples as long as
 *                                              both events are detected and
 *                                              script must be manually stopped
 *                                              by the application
 *                                              0: The amount of samples to be
 *                                              transferred is equal to the
 *                                              count field of mode word
 */
#define SDMA_WATERMARK_LEVEL_LWML       0xFF
#define SDMA_WATERMARK_LEVEL_PS         BIT(8)
#define SDMA_WATERMARK_LEVEL_PA         BIT(9)
#define SDMA_WATERMARK_LEVEL_SPDIF      BIT(10)
#define SDMA_WATERMARK_LEVEL_SP         BIT(11)
#define SDMA_WATERMARK_LEVEL_DP         BIT(12)
#define SDMA_WATERMARK_LEVEL_HWML       (0xFF << 16)
#define SDMA_WATERMARK_LEVEL_LWE        BIT(28)
#define SDMA_WATERMARK_LEVEL_HWE        BIT(29)
#define SDMA_WATERMARK_LEVEL_CONT       BIT(31)

#define SDMA_DMA_BUSWIDTHS      (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
                                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
                                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))

#define SDMA_DMA_DIRECTIONS     (BIT(DMA_DEV_TO_MEM) | \
                                 BIT(DMA_MEM_TO_DEV) | \
                                 BIT(DMA_DEV_TO_DEV))

/*
 * Mode/Count of data node descriptors - IPCv2
 */
struct sdma_mode_count {
#define SDMA_BD_MAX_CNT 0xffff
        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 mostly 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
 * @unused1:    unused
 * @t:          test bit: status of arithmetic & test instruction
 * @rpc:        return program counter
 * @unused0:    unused
 * @sf:         source fault while loading data
 * @spc:        loop start program counter
 * @unused2:    unused
 * @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
 * @scratch0:           1st word of dedicated ram for context switch
 * @scratch1:           2nd word of dedicated ram for context switch
 * @scratch2:           3rd word of dedicated ram for context switch
 * @scratch3:           4th word of dedicated ram for context switch
 * @scratch4:           5th word of dedicated ram for context switch
 * @scratch5:           6th word of dedicated ram for context switch
 * @scratch6:           7th word of dedicated ram for context switch
 * @scratch7:           8th word of dedicated ram for context switch
 */
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));


struct sdma_engine;

/**
 * struct sdma_desc - descriptor structor for one transfer
 * @vd:                 descriptor for virt dma
 * @num_bd:             number of descriptors currently handling
 * @bd_phys:            physical address of bd
 * @buf_tail:           ID of the buffer that was processed
 * @buf_ptail:          ID of the previous buffer that was processed
 * @period_len:         period length, used in cyclic.
 * @chn_real_count:     the real count updated from bd->mode.count
 * @chn_count:          the transfer count set
 * @sdmac:              sdma_channel pointer
 * @bd:                 pointer of allocate bd
 */
struct sdma_desc {
        struct virt_dma_desc    vd;
        unsigned int            num_bd;
        dma_addr_t              bd_phys;
        unsigned int            buf_tail;
        unsigned int            buf_ptail;
        unsigned int            period_len;
        unsigned int            chn_real_count;
        unsigned int            chn_count;
        struct sdma_channel     *sdmac;
        struct sdma_buffer_descriptor *bd;
};

/**
 * struct sdma_channel - housekeeping for a SDMA channel
 *
 * @vc:                 virt_dma base structure
 * @desc:               sdma description including vd and other special member
 * @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
 * @slave_config        Slave configuration
 * @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
 * @pc_from_device:     script address for those device_2_memory
 * @pc_to_device:       script address for those memory_2_device
 * @device_to_device:   script address for those device_2_device
 * @pc_to_pc:           script address for those memory_2_memory
 * @flags:              loop mode or not
 * @per_address:        peripheral source or destination address in common case
 *                      destination address in p_2_p case
 * @per_address2:       peripheral source address in p_2_p case
 * @event_mask:         event mask used in p_2_p script
 * @watermark_level:    value for gReg[7], some script will extend it from
 *                      basic watermark such as p_2_p
 * @shp_addr:           value for gReg[6]
 * @per_addr:           value for gReg[2]
 * @status:             status of dma channel
 * @data:               specific sdma interface structure
 * @bd_pool:            dma_pool for bd
 */
struct sdma_channel {
        struct virt_dma_chan            vc;
        struct sdma_desc                *desc;
        struct sdma_engine              *sdma;
        unsigned int                    channel;
        enum dma_transfer_direction             direction;
        struct dma_slave_config         slave_config;
        enum sdma_peripheral_type       peripheral_type;
        unsigned int                    event_id0;
        unsigned int                    event_id1;
        enum dma_slave_buswidth         word_size;
        unsigned int                    pc_from_device, pc_to_device;
        unsigned int                    device_to_device;
        unsigned int                    pc_to_pc;
        unsigned long                   flags;
        dma_addr_t                      per_address, per_address2;
        unsigned long                   event_mask[2];
        unsigned long                   watermark_level;
        u32                             shp_addr, per_addr;
        enum dma_status                 status;
        struct imx_dma_data             data;
        struct work_struct              terminate_worker;
};

#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;
        u32                             spba_start_addr;
        u32                             spba_end_addr;
        unsigned int                    irq;
        dma_addr_t                      bd0_phys;
        struct sdma_buffer_descriptor   *bd0;
};

static int sdma_config_write(struct dma_chan *chan,
                       struct dma_slave_config *dmaengine_cfg,
                       enum dma_transfer_direction direction);

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 sdma_script_start_addrs sdma_script_imx7d = {
        .ap_2_ap_addr = 644,
        .uart_2_mcu_addr = 819,
        .mcu_2_app_addr = 749,
        .uartsh_2_mcu_addr = 1034,
        .mcu_2_shp_addr = 962,
        .app_2_mcu_addr = 685,
        .shp_2_mcu_addr = 893,
        .spdif_2_mcu_addr = 1102,
        .mcu_2_spdif_addr = 1136,
};

static struct sdma_driver_data sdma_imx7d = {
        .chnenbl0 = SDMA_CHNENBL0_IMX35,
        .num_events = 48,
        .script_addrs = &sdma_script_imx7d,
};

static const 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,
        }, {
                .name = "imx7d-sdma",
                .driver_data = (unsigned long)&sdma_imx7d,
        }, {
                /* 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, },
        { .compatible = "fsl,imx7d-sdma", .data = &sdma_imx7d, },
        { /* 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;
        u32 reg;

        sdma_enable_channel(sdma, 0);

        ret = readl_relaxed_poll_timeout_atomic(sdma->regs + SDMA_H_STATSTOP,
                                                reg, !(reg & 1), 1, 500);
        if (ret)
                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;
}

static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
                u32 address)
{
        struct sdma_buffer_descriptor *bd0 = sdma->bd0;
        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 struct sdma_desc *to_sdma_desc(struct dma_async_tx_descriptor *t)
{
        return container_of(t, struct sdma_desc, vd.tx);
}

static void sdma_start_desc(struct sdma_channel *sdmac)
{
        struct virt_dma_desc *vd = vchan_next_desc(&sdmac->vc);
        struct sdma_desc *desc;
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;

        if (!vd) {
                sdmac->desc = NULL;
                return;
        }
        sdmac->desc = desc = to_sdma_desc(&vd->tx);
        /*
         * Do not delete the node in desc_issued list in cyclic mode, otherwise
         * the desc allocated will never be freed in vchan_dma_desc_free_list
         */
        if (!(sdmac->flags & IMX_DMA_SG_LOOP))
                list_del(&vd->node);

        sdma->channel_control[channel].base_bd_ptr = desc->bd_phys;
        sdma->channel_control[channel].current_bd_ptr = desc->bd_phys;
        sdma_enable_channel(sdma, sdmac->channel);
}

static void sdma_update_channel_loop(struct sdma_channel *sdmac)
{
        struct sdma_buffer_descriptor *bd;
        int error = 0;
        enum dma_status old_status = sdmac->status;

        /*
         * loop mode. Iterate over descriptors, re-setup them and
         * call callback function.
         */
        while (sdmac->desc) {
                struct sdma_desc *desc = sdmac->desc;

                bd = &desc->bd[desc->buf_tail];

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

                if (bd->mode.status & BD_RROR) {
                        bd->mode.status &= ~BD_RROR;
                        sdmac->status = DMA_ERROR;
                        error = -EIO;
                }

               /*
                * We use bd->mode.count to calculate the residue, since contains
                * the number of bytes present in the current buffer descriptor.
                */

                desc->chn_real_count = bd->mode.count;
                bd->mode.status |= BD_DONE;
                bd->mode.count = desc->period_len;
                desc->buf_ptail = desc->buf_tail;
                desc->buf_tail = (desc->buf_tail + 1) % desc->num_bd;

                /*
                 * The callback is called from the interrupt context in order
                 * to reduce latency and to avoid the risk of altering the
                 * SDMA transaction status by the time the client tasklet is
                 * executed.
                 */
                spin_unlock(&sdmac->vc.lock);
                dmaengine_desc_get_callback_invoke(&desc->vd.tx, NULL);
                spin_lock(&sdmac->vc.lock);

                if (error)
                        sdmac->status = old_status;
        }
}

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

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

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

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

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);
        writel_relaxed(stat, sdma->regs + SDMA_H_INTR);
        /* channel 0 is special and not handled here, see run_channel0() */
        stat &= ~1;

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

                spin_lock(&sdmac->vc.lock);
                desc = sdmac->desc;
                if (desc) {
                        if (sdmac->flags & IMX_DMA_SG_LOOP) {
                                sdma_update_channel_loop(sdmac);
                        } else {
                                mxc_sdma_handle_channel_normal(sdmac);
                                vchan_cookie_complete(&desc->vd);
                                sdma_start_desc(sdmac);
                        }
                }

                spin_unlock(&sdmac->vc.lock);
                __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;
        sdmac->device_to_device = 0;
        sdmac->pc_to_pc = 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;
        sdmac->device_to_device = per_2_per;
        sdmac->pc_to_pc = emi_2_emi;
}

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->bd0;
        int ret;
        unsigned long flags;

        if (sdmac->direction == DMA_DEV_TO_MEM)
                load_address = sdmac->pc_from_device;
        else if (sdmac->direction == DMA_DEV_TO_DEV)
                load_address = sdmac->device_to_device;
        else if (sdmac->direction == DMA_MEM_TO_MEM)
                load_address = sdmac->pc_to_pc;
        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, vc.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 void sdma_channel_terminate_work(struct work_struct *work)
{
        struct sdma_channel *sdmac = container_of(work, struct sdma_channel,
                                                  terminate_worker);
        unsigned long flags;
        LIST_HEAD(head);

        /*
         * According to NXP R&D team a delay of one BD SDMA cost time
         * (maximum is 1ms) should be added after disable of the channel
         * bit, to ensure SDMA core has really been stopped after SDMA
         * clients call .device_terminate_all.
         */
        usleep_range(1000, 2000);

        spin_lock_irqsave(&sdmac->vc.lock, flags);
        vchan_get_all_descriptors(&sdmac->vc, &head);
        sdmac->desc = NULL;
        spin_unlock_irqrestore(&sdmac->vc.lock, flags);
        vchan_dma_desc_free_list(&sdmac->vc, &head);
}

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

        sdma_disable_channel(chan);

        if (sdmac->desc)
                schedule_work(&sdmac->terminate_worker);

        return 0;
}

static void sdma_channel_synchronize(struct dma_chan *chan)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);

        vchan_synchronize(&sdmac->vc);

        flush_work(&sdmac->terminate_worker);
}

static void sdma_set_watermarklevel_for_p2p(struct sdma_channel *sdmac)
{
        struct sdma_engine *sdma = sdmac->sdma;

        int lwml = sdmac->watermark_level & SDMA_WATERMARK_LEVEL_LWML;
        int hwml = (sdmac->watermark_level & SDMA_WATERMARK_LEVEL_HWML) >> 16;

        set_bit(sdmac->event_id0 % 32, &sdmac->event_mask[1]);
        set_bit(sdmac->event_id1 % 32, &sdmac->event_mask[0]);

        if (sdmac->event_id0 > 31)
                sdmac->watermark_level |= SDMA_WATERMARK_LEVEL_LWE;

        if (sdmac->event_id1 > 31)
                sdmac->watermark_level |= SDMA_WATERMARK_LEVEL_HWE;

        /*
         * If LWML(src_maxburst) > HWML(dst_maxburst), we need
         * swap LWML and HWML of INFO(A.3.2.5.1), also need swap
         * r0(event_mask[1]) and r1(event_mask[0]).
         */
        if (lwml > hwml) {
                sdmac->watermark_level &= ~(SDMA_WATERMARK_LEVEL_LWML |
                                                SDMA_WATERMARK_LEVEL_HWML);
                sdmac->watermark_level |= hwml;
                sdmac->watermark_level |= lwml << 16;
                swap(sdmac->event_mask[0], sdmac->event_mask[1]);
        }

        if (sdmac->per_address2 >= sdma->spba_start_addr &&
                        sdmac->per_address2 <= sdma->spba_end_addr)
                sdmac->watermark_level |= SDMA_WATERMARK_LEVEL_SP;

        if (sdmac->per_address >= sdma->spba_start_addr &&
                        sdmac->per_address <= sdma->spba_end_addr)
                sdmac->watermark_level |= SDMA_WATERMARK_LEVEL_DP;

        sdmac->watermark_level |= SDMA_WATERMARK_LEVEL_CONT;
}

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;

        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) {
                        if (sdmac->peripheral_type == IMX_DMATYPE_ASRC_SP ||
                            sdmac->peripheral_type == IMX_DMATYPE_ASRC)
                                sdma_set_watermarklevel_for_p2p(sdmac);
                } else
                        __set_bit(sdmac->event_id0, sdmac->event_mask);

                /* Address */
                sdmac->shp_addr = sdmac->per_address;
                sdmac->per_addr = sdmac->per_address2;
        } 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_channel0(struct sdma_engine *sdma)
{
        int ret = -EBUSY;

        sdma->bd0 = dma_alloc_coherent(NULL, PAGE_SIZE, &sdma->bd0_phys,
                                       GFP_NOWAIT);
        if (!sdma->bd0) {
                ret = -ENOMEM;
                goto out;
        }

        sdma->channel_control[0].base_bd_ptr = sdma->bd0_phys;
        sdma->channel_control[0].current_bd_ptr = sdma->bd0_phys;

        sdma_set_channel_priority(&sdma->channel[0], MXC_SDMA_DEFAULT_PRIORITY);
        return 0;
out:

        return ret;
}


static int sdma_alloc_bd(struct sdma_desc *desc)
{
        u32 bd_size = desc->num_bd * sizeof(struct sdma_buffer_descriptor);
        int ret = 0;

        desc->bd = dma_alloc_coherent(NULL, bd_size, &desc->bd_phys,
                                      GFP_NOWAIT);
        if (!desc->bd) {
                ret = -ENOMEM;
                goto out;
        }
out:
        return ret;
}

static void sdma_free_bd(struct sdma_desc *desc)
{
        u32 bd_size = desc->num_bd * sizeof(struct sdma_buffer_descriptor);

        dma_free_coherent(NULL, bd_size, desc->bd, desc->bd_phys);
}

static void sdma_desc_free(struct virt_dma_desc *vd)
{
        struct sdma_desc *desc = container_of(vd, struct sdma_desc, vd);

        sdma_free_bd(desc);
        kfree(desc);
}

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;
        struct imx_dma_data mem_data;
        int prio, ret;

        /*
         * MEMCPY may never setup chan->private by filter function such as
         * dmatest, thus create 'struct imx_dma_data mem_data' for this case.
         * Please note in any other slave case, you have to setup chan->private
         * with 'struct imx_dma_data' in your own filter function if you want to
         * request dma channel by dma_request_channel() rather than
         * dma_request_slave_channel(). Othwise, 'MEMCPY in case?' will appear
         * to warn you to correct your filter function.
         */
        if (!data) {
                dev_dbg(sdmac->sdma->dev, "MEMCPY in case?\n");
                mem_data.priority = 2;
                mem_data.peripheral_type = IMX_DMATYPE_MEMORY;
                mem_data.dma_request = 0;
                mem_data.dma_request2 = 0;
                data = &mem_data;

                sdma_get_pc(sdmac, IMX_DMATYPE_MEMORY);
        }

        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;
        sdmac->event_id1 = data->dma_request2;

        ret = clk_enable(sdmac->sdma->clk_ipg);
        if (ret)
                return ret;
        ret = clk_enable(sdmac->sdma->clk_ahb);
        if (ret)
                goto disable_clk_ipg;

        ret = sdma_set_channel_priority(sdmac, prio);
        if (ret)
                goto disable_clk_ahb;

        return 0;

disable_clk_ahb:
        clk_disable(sdmac->sdma->clk_ahb);
disable_clk_ipg:
        clk_disable(sdmac->sdma->clk_ipg);
        return ret;
}

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_async(chan);

        sdma_channel_synchronize(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);

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

static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac,
                                enum dma_transfer_direction direction, u32 bds)
{
        struct sdma_desc *desc;

        desc = kzalloc((sizeof(*desc)), GFP_NOWAIT);
        if (!desc)
                goto err_out;

        sdmac->status = DMA_IN_PROGRESS;
        sdmac->direction = direction;
        sdmac->flags = 0;

        desc->chn_count = 0;
        desc->chn_real_count = 0;
        desc->buf_tail = 0;
        desc->buf_ptail = 0;
        desc->sdmac = sdmac;
        desc->num_bd = bds;

        if (sdma_alloc_bd(desc))
                goto err_desc_out;

        /* No slave_config called in MEMCPY case, so do here */
        if (direction == DMA_MEM_TO_MEM)
                sdma_config_ownership(sdmac, false, true, false);

        if (sdma_load_context(sdmac))
                goto err_desc_out;

        return desc;

err_desc_out:
        kfree(desc);
err_out:
        return NULL;
}

static struct dma_async_tx_descriptor *sdma_prep_memcpy(
                struct dma_chan *chan, dma_addr_t dma_dst,
                dma_addr_t dma_src, size_t len, unsigned long flags)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);
        struct sdma_engine *sdma = sdmac->sdma;
        int channel = sdmac->channel;
        size_t count;
        int i = 0, param;
        struct sdma_buffer_descriptor *bd;
        struct sdma_desc *desc;

        if (!chan || !len)
                return NULL;

        dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
                &dma_src, &dma_dst, len, channel);

        desc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM,
                                        len / SDMA_BD_MAX_CNT + 1);
        if (!desc)
                return NULL;

        do {
                count = min_t(size_t, len, SDMA_BD_MAX_CNT);
                bd = &desc->bd[i];
                bd->buffer_addr = dma_src;
                bd->ext_buffer_addr = dma_dst;
                bd->mode.count = count;
                desc->chn_count += count;
                bd->mode.command = 0;

                dma_src += count;
                dma_dst += count;
                len -= count;
                i++;

                param = BD_DONE | BD_EXTD | BD_CONT;
                /* last bd */
                if (!len) {
                        param |= BD_INTR;
                        param |= BD_LAST;
                        param &= ~BD_CONT;
                }

                dev_dbg(sdma->dev, "entry %d: count: %zd dma: 0x%x %s%s\n",
                                i, count, bd->buffer_addr,
                                param & BD_WRAP ? "wrap" : "",
                                param & BD_INTR ? " intr" : "");

                bd->mode.status = param;
        } while (len);

        return vchan_tx_prep(&sdmac->vc, &desc->vd, flags);
}

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 i, count;
        int channel = sdmac->channel;
        struct scatterlist *sg;
        struct sdma_desc *desc;

        sdma_config_write(chan, &sdmac->slave_config, direction);

        desc = sdma_transfer_init(sdmac, direction, sg_len);
        if (!desc)
                goto err_out;

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

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

                bd->buffer_addr = sg->dma_address;

                count = sg_dma_len(sg);

                if (count > SDMA_BD_MAX_CNT) {
                        dev_err(sdma->dev, "SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n",
                                        channel, count, SDMA_BD_MAX_CNT);
                        goto err_bd_out;
                }

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

                if (sdmac->word_size > DMA_SLAVE_BUSWIDTH_4_BYTES)
                        goto err_bd_out;

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

                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;
        }

        return vchan_tx_prep(&sdmac->vc, &desc->vd, flags);
err_bd_out:
        sdma_free_bd(desc);
        kfree(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 i = 0, buf = 0;
        struct sdma_desc *desc;

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

        sdma_config_write(chan, &sdmac->slave_config, direction);

        desc = sdma_transfer_init(sdmac, direction, num_periods);
        if (!desc)
                goto err_out;

        desc->period_len = period_len;

        sdmac->flags |= IMX_DMA_SG_LOOP;

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

        while (buf < buf_len) {
                struct sdma_buffer_descriptor *bd = &desc->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_bd_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: %zu 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++;
        }

        return vchan_tx_prep(&sdmac->vc, &desc->vd, flags);
err_bd_out:
        sdma_free_bd(desc);
        kfree(desc);
err_out:
        sdmac->status = DMA_ERROR;
        return NULL;
}

static int sdma_config_write(struct dma_chan *chan,
                       struct dma_slave_config *dmaengine_cfg,
                       enum dma_transfer_direction direction)
{
        struct sdma_channel *sdmac = to_sdma_chan(chan);

        if (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 if (direction == DMA_DEV_TO_DEV) {
                sdmac->per_address2 = dmaengine_cfg->src_addr;
                sdmac->per_address = dmaengine_cfg->dst_addr;
                sdmac->watermark_level = dmaengine_cfg->src_maxburst &
                        SDMA_WATERMARK_LEVEL_LWML;
                sdmac->watermark_level |= (dmaengine_cfg->dst_maxburst << 16) &
                        SDMA_WATERMARK_LEVEL_HWML;
                sdmac->word_size = dmaengine_cfg->dst_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 = direction;
        return sdma_config_channel(chan);
}

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

        memcpy(&sdmac->slave_config, dmaengine_cfg, sizeof(*dmaengine_cfg));

        /* Set ENBLn earlier to make sure dma request triggered after that */
        if (sdmac->event_id0) {
                if (sdmac->event_id0 >= sdmac->sdma->drvdata->num_events)
                        return -EINVAL;
                sdma_event_enable(sdmac, sdmac->event_id0);
        }

        if (sdmac->event_id1) {
                if (sdmac->event_id1 >= sdmac->sdma->drvdata->num_events)
                        return -EINVAL;
                sdma_event_enable(sdmac, sdmac->event_id1);
        }

        return 0;
}

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);
        struct sdma_desc *desc;
        u32 residue;
        struct virt_dma_desc *vd;
        enum dma_status ret;
        unsigned long flags;

        ret = dma_cookie_status(chan, cookie, txstate);
        if (ret == DMA_COMPLETE || !txstate)
                return ret;

        spin_lock_irqsave(&sdmac->vc.lock, flags);
        vd = vchan_find_desc(&sdmac->vc, cookie);
        if (vd) {
                desc = to_sdma_desc(&vd->tx);
                if (sdmac->flags & IMX_DMA_SG_LOOP)
                        residue = (desc->num_bd - desc->buf_ptail) *
                                desc->period_len - desc->chn_real_count;
                else
                        residue = desc->chn_count - desc->chn_real_count;
        } else if (sdmac->desc && sdmac->desc->vd.tx.cookie == cookie) {
                residue = sdmac->desc->chn_count - sdmac->desc->chn_real_count;
        } else {
                residue = 0;
        }
        spin_unlock_irqrestore(&sdmac->vc.lock, flags);

        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);
        unsigned long flags;

        spin_lock_irqsave(&sdmac->vc.lock, flags);
        if (vchan_issue_pending(&sdmac->vc) && !sdmac->desc)
                sdma_start_desc(sdmac);
        spin_unlock_irqrestore(&sdmac->vc.lock, flags);
}

#define SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V1 34
#define SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V2 38
#define SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V3 41
#define SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V4 42

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;
        case 3:
                sdma->script_number = SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V3;
                break;
        case 4:
                sdma->script_number = SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V4;
                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);
}

#define EVENT_REMAP_CELLS 3

static int sdma_event_remap(struct sdma_engine *sdma)
{
        struct device_node *np = sdma->dev->of_node;
        struct device_node *gpr_np = of_parse_phandle(np, "gpr", 0);
        struct property *event_remap;
        struct regmap *gpr;
        char propname[] = "fsl,sdma-event-remap";
        u32 reg, val, shift, num_map, i;
        int ret = 0;

        if (IS_ERR(np) || IS_ERR(gpr_np))
                goto out;

        event_remap = of_find_property(np, propname, NULL);
        num_map = event_remap ? (event_remap->length / sizeof(u32)) : 0;
        if (!num_map) {
                dev_dbg(sdma->dev, "no event needs to be remapped\n");
                goto out;
        } else if (num_map % EVENT_REMAP_CELLS) {
                dev_err(sdma->dev, "the property %s must modulo %d\n",
                                propname, EVENT_REMAP_CELLS);
                ret = -EINVAL;
                goto out;
        }

        gpr = syscon_node_to_regmap(gpr_np);
        if (IS_ERR(gpr)) {
                dev_err(sdma->dev, "failed to get gpr regmap\n");
                ret = PTR_ERR(gpr);
                goto out;
        }

        for (i = 0; i < num_map; i += EVENT_REMAP_CELLS) {
                ret = of_property_read_u32_index(np, propname, i, &reg);
                if (ret) {
                        dev_err(sdma->dev, "failed to read property %s index %d\n",
                                        propname, i);
                        goto out;
                }

                ret = of_property_read_u32_index(np, propname, i + 1, &shift);
                if (ret) {
                        dev_err(sdma->dev, "failed to read property %s index %d\n",
                                        propname, i + 1);
                        goto out;
                }

                ret = of_property_read_u32_index(np, propname, i + 2, &val);
                if (ret) {
                        dev_err(sdma->dev, "failed to read property %s index %d\n",
                                        propname, i + 2);
                        goto out;
                }

                regmap_update_bits(gpr, reg, BIT(shift), val << shift);
        }

out:
        if (!IS_ERR(gpr_np))
                of_node_put(gpr_np);

        return ret;
}

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;

        ret = clk_enable(sdma->clk_ipg);
        if (ret)
                return ret;
        ret = clk_enable(sdma->clk_ahb);
        if (ret)
                goto disable_clk_ipg;

        /* 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_channel0(sdma);
        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_ahb);
disable_clk_ipg:
        clk_disable(sdma->clk_ipg);
        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];
        /*
         * init dma_request2 to zero, which is not used by the dts.
         * For P2P, dma_request2 is init from dma_request_channel(),
         * chan->private will point to the imx_dma_data, and in
         * device_alloc_chan_resources(), imx_dma_data.dma_request2 will
         * be set to sdmac->event_id1.
         */
        data.dma_request2 = 0;

        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;
        struct device_node *spba_bus;
        const char *fw_name;
        int ret;
        int irq;
        struct resource *iores;
        struct resource spba_res;
        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);

        ret = clk_prepare(sdma->clk_ipg);
        if (ret)

                return ret;

        ret = clk_prepare(sdma->clk_ahb);
        if (ret)
                goto err_clk;

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

        sdma->irq = irq;

        sdma->script_addrs = kzalloc(sizeof(*sdma->script_addrs), GFP_KERNEL);
        if (!sdma->script_addrs) {
                ret = -ENOMEM;
                goto err_irq;
        }

        /* 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);
        dma_cap_set(DMA_MEMCPY, 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;

                sdmac->channel = i;
                sdmac->vc.desc_free = sdma_desc_free;
                INIT_WORK(&sdmac->terminate_worker,
                                sdma_channel_terminate_work);
                /*
                 * 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)
                        vchan_init(&sdmac->vc, &sdma->dma_device);
        }

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

        ret = sdma_event_remap(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_async;
        sdma->dma_device.device_synchronize = sdma_channel_synchronize;
        sdma->dma_device.src_addr_widths = SDMA_DMA_BUSWIDTHS;
        sdma->dma_device.dst_addr_widths = SDMA_DMA_BUSWIDTHS;
        sdma->dma_device.directions = SDMA_DMA_DIRECTIONS;
        sdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
        sdma->dma_device.device_prep_dma_memcpy = sdma_prep_memcpy;
        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, SDMA_BD_MAX_CNT);

        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;
                }

                spba_bus = of_find_compatible_node(NULL, NULL, "fsl,spba-bus");
                ret = of_address_to_resource(spba_bus, 0, &spba_res);
                if (!ret) {
                        sdma->spba_start_addr = spba_res.start;
                        sdma->spba_end_addr = spba_res.end;
                }
                of_node_put(spba_bus);
        }

        return 0;

err_register:
        dma_async_device_unregister(&sdma->dma_device);
err_init:
        kfree(sdma->script_addrs);
err_irq:
        clk_unprepare(sdma->clk_ahb);
err_clk:
        clk_unprepare(sdma->clk_ipg);
        return ret;
}

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

        devm_free_irq(&pdev->dev, sdma->irq, sdma);
        dma_async_device_unregister(&sdma->dma_device);
        kfree(sdma->script_addrs);
        clk_unprepare(sdma->clk_ahb);
        clk_unprepare(sdma->clk_ipg);
        /* Kill the tasklet */
        for (i = 0; i < MAX_DMA_CHANNELS; i++) {
                struct sdma_channel *sdmac = &sdma->channel[i];

                tasklet_kill(&sdmac->vc.task);
                sdma_free_chan_resources(&sdmac->vc.chan);
        }

        platform_set_drvdata(pdev, NULL);
        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");
#if IS_ENABLED(CONFIG_SOC_IMX6Q)
MODULE_FIRMWARE("imx/sdma/sdma-imx6q.bin");
#endif
#if IS_ENABLED(CONFIG_SOC_IMX7D)
MODULE_FIRMWARE("imx/sdma/sdma-imx7d.bin");
#endif
MODULE_LICENSE("GPL");