/*
 * AMD ALSA SoC PCM Driver for ACP 2.x
 *
 * Copyright 2014-2015 Advanced Micro Devices, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/sizes.h>
#include <linux/pm_runtime.h>

#include <sound/soc.h>

#include "acp.h"

#define PLAYBACK_MIN_NUM_PERIODS    2
#define PLAYBACK_MAX_NUM_PERIODS    2
#define PLAYBACK_MAX_PERIOD_SIZE    16384
#define PLAYBACK_MIN_PERIOD_SIZE    1024
#define CAPTURE_MIN_NUM_PERIODS     2
#define CAPTURE_MAX_NUM_PERIODS     2
#define CAPTURE_MAX_PERIOD_SIZE     16384
#define CAPTURE_MIN_PERIOD_SIZE     1024

#define MAX_BUFFER (PLAYBACK_MAX_PERIOD_SIZE * PLAYBACK_MAX_NUM_PERIODS)
#define MIN_BUFFER MAX_BUFFER

static const struct snd_pcm_hardware acp_pcm_hardware_playback = {
        .info = SNDRV_PCM_INFO_INTERLEAVED |
                SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP |
                SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_BATCH |
                SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
        .formats = SNDRV_PCM_FMTBIT_S16_LE |
                SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE,
        .channels_min = 1,
        .channels_max = 8,
        .rates = SNDRV_PCM_RATE_8000_96000,
        .rate_min = 8000,
        .rate_max = 96000,
        .buffer_bytes_max = PLAYBACK_MAX_NUM_PERIODS * PLAYBACK_MAX_PERIOD_SIZE,
        .period_bytes_min = PLAYBACK_MIN_PERIOD_SIZE,
        .period_bytes_max = PLAYBACK_MAX_PERIOD_SIZE,
        .periods_min = PLAYBACK_MIN_NUM_PERIODS,
        .periods_max = PLAYBACK_MAX_NUM_PERIODS,
};

static const struct snd_pcm_hardware acp_pcm_hardware_capture = {
        .info = SNDRV_PCM_INFO_INTERLEAVED |
                SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP |
                SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_BATCH |
            SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
        .formats = SNDRV_PCM_FMTBIT_S16_LE |
                SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE,
        .channels_min = 1,
        .channels_max = 2,
        .rates = SNDRV_PCM_RATE_8000_48000,
        .rate_min = 8000,
        .rate_max = 48000,
        .buffer_bytes_max = CAPTURE_MAX_NUM_PERIODS * CAPTURE_MAX_PERIOD_SIZE,
        .period_bytes_min = CAPTURE_MIN_PERIOD_SIZE,
        .period_bytes_max = CAPTURE_MAX_PERIOD_SIZE,
        .periods_min = CAPTURE_MIN_NUM_PERIODS,
        .periods_max = CAPTURE_MAX_NUM_PERIODS,
};

struct audio_drv_data {
        struct snd_pcm_substream *play_stream;
        struct snd_pcm_substream *capture_stream;
        void __iomem *acp_mmio;
};

static u32 acp_reg_read(void __iomem *acp_mmio, u32 reg)
{
        return readl(acp_mmio + (reg * 4));
}

static void acp_reg_write(u32 val, void __iomem *acp_mmio, u32 reg)
{
        writel(val, acp_mmio + (reg * 4));
}

/* Configure a given dma channel parameters - enable/disble,
 * number of descriptors, priority
 */
static void config_acp_dma_channel(void __iomem *acp_mmio, u8 ch_num,
                                   u16 dscr_strt_idx, u16 num_dscrs,
                                   enum acp_dma_priority_level priority_level)
{
        u32 dma_ctrl;

        /* disable the channel run field */
        dma_ctrl = acp_reg_read(acp_mmio, mmACP_DMA_CNTL_0 + ch_num);
        dma_ctrl &= ~ACP_DMA_CNTL_0__DMAChRun_MASK;
        acp_reg_write(dma_ctrl, acp_mmio, mmACP_DMA_CNTL_0 + ch_num);

        /* program a DMA channel with first descriptor to be processed. */
        acp_reg_write((ACP_DMA_DSCR_STRT_IDX_0__DMAChDscrStrtIdx_MASK
                        & dscr_strt_idx),
                        acp_mmio, mmACP_DMA_DSCR_STRT_IDX_0 + ch_num);

        /* program a DMA channel with the number of descriptors to be
         * processed in the transfer
        */
        acp_reg_write(ACP_DMA_DSCR_CNT_0__DMAChDscrCnt_MASK & num_dscrs,
                acp_mmio, mmACP_DMA_DSCR_CNT_0 + ch_num);

        /* set DMA channel priority */
        acp_reg_write(priority_level, acp_mmio, mmACP_DMA_PRIO_0 + ch_num);
}

/* Initialize a dma descriptor in SRAM based on descritor information passed */
static void config_dma_descriptor_in_sram(void __iomem *acp_mmio,
                                          u16 descr_idx,
                                          acp_dma_dscr_transfer_t *descr_info)
{
        u32 sram_offset;

        sram_offset = (descr_idx * sizeof(acp_dma_dscr_transfer_t));

        /* program the source base address. */
        acp_reg_write(sram_offset, acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
        acp_reg_write(descr_info->src,  acp_mmio, mmACP_SRBM_Targ_Idx_Data);
        /* program the destination base address. */
        acp_reg_write(sram_offset + 4,  acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
        acp_reg_write(descr_info->dest, acp_mmio, mmACP_SRBM_Targ_Idx_Data);

        /* program the number of bytes to be transferred for this descriptor. */
        acp_reg_write(sram_offset + 8,  acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
        acp_reg_write(descr_info->xfer_val, acp_mmio, mmACP_SRBM_Targ_Idx_Data);
}

/* Initialize the DMA descriptor information for transfer between
 * system memory <-> ACP SRAM
 */
static void set_acp_sysmem_dma_descriptors(void __iomem *acp_mmio,
                                           u32 size, int direction,
                                           u32 pte_offset)
{
        u16 i;
        u16 dma_dscr_idx = PLAYBACK_START_DMA_DESCR_CH12;
        acp_dma_dscr_transfer_t dmadscr[NUM_DSCRS_PER_CHANNEL];

        for (i = 0; i < NUM_DSCRS_PER_CHANNEL; i++) {
                dmadscr[i].xfer_val = 0;
                if (direction == SNDRV_PCM_STREAM_PLAYBACK) {
                        dma_dscr_idx = PLAYBACK_START_DMA_DESCR_CH12 + i;
                        dmadscr[i].dest = ACP_SHARED_RAM_BANK_1_ADDRESS +
                                        (size / 2) - (i * (size/2));
                        dmadscr[i].src = ACP_INTERNAL_APERTURE_WINDOW_0_ADDRESS
                                + (pte_offset * SZ_4K) + (i * (size/2));
                        dmadscr[i].xfer_val |=
                        (ACP_DMA_ATTRIBUTES_DAGB_ONION_TO_SHAREDMEM << 16) |
                        (size / 2);
                } else {
                        dma_dscr_idx = CAPTURE_START_DMA_DESCR_CH14 + i;
                        dmadscr[i].src = ACP_SHARED_RAM_BANK_5_ADDRESS +
                                        (i * (size/2));
                        dmadscr[i].dest = ACP_INTERNAL_APERTURE_WINDOW_0_ADDRESS
                                                + (pte_offset * SZ_4K) +
                                                (i * (size/2));
                        dmadscr[i].xfer_val |=
                        BIT(22) |
                        (ACP_DMA_ATTRIBUTES_SHAREDMEM_TO_DAGB_ONION << 16) |
                        (size / 2);
                }
                config_dma_descriptor_in_sram(acp_mmio, dma_dscr_idx,
                                                &dmadscr[i]);
        }
        if (direction == SNDRV_PCM_STREAM_PLAYBACK)
                config_acp_dma_channel(acp_mmio, SYSRAM_TO_ACP_CH_NUM,
                                        PLAYBACK_START_DMA_DESCR_CH12,
                                        NUM_DSCRS_PER_CHANNEL,
                                        ACP_DMA_PRIORITY_LEVEL_NORMAL);
        else
                config_acp_dma_channel(acp_mmio, ACP_TO_SYSRAM_CH_NUM,
                                        CAPTURE_START_DMA_DESCR_CH14,
                                        NUM_DSCRS_PER_CHANNEL,
                                        ACP_DMA_PRIORITY_LEVEL_NORMAL);
}

/* Initialize the DMA descriptor information for transfer between
 * ACP SRAM <-> I2S
 */
static void set_acp_to_i2s_dma_descriptors(void __iomem *acp_mmio,
                                           u32 size, int direction)
{

        u16 i;
        u16 dma_dscr_idx = PLAYBACK_START_DMA_DESCR_CH13;
        acp_dma_dscr_transfer_t dmadscr[NUM_DSCRS_PER_CHANNEL];

        for (i = 0; i < NUM_DSCRS_PER_CHANNEL; i++) {
                dmadscr[i].xfer_val = 0;
                if (direction == SNDRV_PCM_STREAM_PLAYBACK) {
                        dma_dscr_idx = PLAYBACK_START_DMA_DESCR_CH13 + i;
                        dmadscr[i].src = ACP_SHARED_RAM_BANK_1_ADDRESS +
                                         (i * (size/2));
                        /* dmadscr[i].dest is unused by hardware. */
                        dmadscr[i].dest = 0;
                        dmadscr[i].xfer_val |= BIT(22) | (TO_ACP_I2S_1 << 16) |
                                                (size / 2);
                } else {
                        dma_dscr_idx = CAPTURE_START_DMA_DESCR_CH15 + i;
                        /* dmadscr[i].src is unused by hardware. */
                        dmadscr[i].src = 0;
                        dmadscr[i].dest = ACP_SHARED_RAM_BANK_5_ADDRESS +
                                        (i * (size / 2));
                        dmadscr[i].xfer_val |= BIT(22) |
                                        (FROM_ACP_I2S_1 << 16) | (size / 2);
                }
                config_dma_descriptor_in_sram(acp_mmio, dma_dscr_idx,
                                                &dmadscr[i]);
        }
        /* Configure the DMA channel with the above descriptore */
        if (direction == SNDRV_PCM_STREAM_PLAYBACK)
                config_acp_dma_channel(acp_mmio, ACP_TO_I2S_DMA_CH_NUM,
                                        PLAYBACK_START_DMA_DESCR_CH13,
                                        NUM_DSCRS_PER_CHANNEL,
                                        ACP_DMA_PRIORITY_LEVEL_NORMAL);
        else
                config_acp_dma_channel(acp_mmio, I2S_TO_ACP_DMA_CH_NUM,
                                        CAPTURE_START_DMA_DESCR_CH15,
                                        NUM_DSCRS_PER_CHANNEL,
                                        ACP_DMA_PRIORITY_LEVEL_NORMAL);
}

/* Create page table entries in ACP SRAM for the allocated memory */
static void acp_pte_config(void __iomem *acp_mmio, struct page *pg,
                           u16 num_of_pages, u32 pte_offset)
{
        u16 page_idx;
        u64 addr;
        u32 low;
        u32 high;
        u32 offset;

        offset  = ACP_DAGB_GRP_SRBM_SRAM_BASE_OFFSET + (pte_offset * 8);
        for (page_idx = 0; page_idx < (num_of_pages); page_idx++) {
                /* Load the low address of page int ACP SRAM through SRBM */
                acp_reg_write((offset + (page_idx * 8)),
                        acp_mmio, mmACP_SRBM_Targ_Idx_Addr);
                addr = page_to_phys(pg);

                low = lower_32_bits(addr);
                high = upper_32_bits(addr);

                acp_reg_write(low, acp_mmio, mmACP_SRBM_Targ_Idx_Data);

                /* Load the High address of page int ACP SRAM through SRBM */
                acp_reg_write((offset + (page_idx * 8) + 4),
                        acp_mmio, mmACP_SRBM_Targ_Idx_Addr);

                /* page enable in ACP */
                high |= BIT(31);
                acp_reg_write(high, acp_mmio, mmACP_SRBM_Targ_Idx_Data);

                /* Move to next physically contiguos page */
                pg++;
        }
}

static void config_acp_dma(void __iomem *acp_mmio,
                           struct audio_substream_data *audio_config)
{
        u32 pte_offset;

        if (audio_config->direction == SNDRV_PCM_STREAM_PLAYBACK)
                pte_offset = ACP_PLAYBACK_PTE_OFFSET;
        else
                pte_offset = ACP_CAPTURE_PTE_OFFSET;

        acp_pte_config(acp_mmio, audio_config->pg, audio_config->num_of_pages,
                        pte_offset);

        /* Configure System memory <-> ACP SRAM DMA descriptors */
        set_acp_sysmem_dma_descriptors(acp_mmio, audio_config->size,
                                       audio_config->direction, pte_offset);

        /* Configure ACP SRAM <-> I2S DMA descriptors */
        set_acp_to_i2s_dma_descriptors(acp_mmio, audio_config->size,
                                        audio_config->direction);
}

/* Start a given DMA channel transfer */
static void acp_dma_start(void __iomem *acp_mmio,
                         u16 ch_num, bool is_circular)
{
        u32 dma_ctrl;

        /* read the dma control register and disable the channel run field */
        dma_ctrl = acp_reg_read(acp_mmio, mmACP_DMA_CNTL_0 + ch_num);

        /* Invalidating the DAGB cache */
        acp_reg_write(1, acp_mmio, mmACP_DAGB_ATU_CTRL);

        /* configure the DMA channel and start the DMA transfer
         * set dmachrun bit to start the transfer and enable the
         * interrupt on completion of the dma transfer
         */
        dma_ctrl |= ACP_DMA_CNTL_0__DMAChRun_MASK;

        switch (ch_num) {
        case ACP_TO_I2S_DMA_CH_NUM:
        case ACP_TO_SYSRAM_CH_NUM:
        case I2S_TO_ACP_DMA_CH_NUM:
                dma_ctrl |= ACP_DMA_CNTL_0__DMAChIOCEn_MASK;
                break;
        default:
                dma_ctrl &= ~ACP_DMA_CNTL_0__DMAChIOCEn_MASK;
                break;
        }

        /* enable  for ACP SRAM to/from I2S DMA channel */
        if (is_circular == true)
                dma_ctrl |= ACP_DMA_CNTL_0__Circular_DMA_En_MASK;
        else
                dma_ctrl &= ~ACP_DMA_CNTL_0__Circular_DMA_En_MASK;

        acp_reg_write(dma_ctrl, acp_mmio, mmACP_DMA_CNTL_0 + ch_num);
}

/* Stop a given DMA channel transfer */
static int acp_dma_stop(void __iomem *acp_mmio, u8 ch_num)
{
        u32 dma_ctrl;
        u32 dma_ch_sts;
        u32 count = ACP_DMA_RESET_TIME;

        dma_ctrl = acp_reg_read(acp_mmio, mmACP_DMA_CNTL_0 + ch_num);

        /* clear the dma control register fields before writing zero
         * in reset bit
        */
        dma_ctrl &= ~ACP_DMA_CNTL_0__DMAChRun_MASK;
        dma_ctrl &= ~ACP_DMA_CNTL_0__DMAChIOCEn_MASK;

        acp_reg_write(dma_ctrl, acp_mmio, mmACP_DMA_CNTL_0 + ch_num);
        dma_ch_sts = acp_reg_read(acp_mmio, mmACP_DMA_CH_STS);

        if (dma_ch_sts & BIT(ch_num)) {
                /* set the reset bit for this channel to stop the dma
                *  transfer
                */
                dma_ctrl |= ACP_DMA_CNTL_0__DMAChRst_MASK;
                acp_reg_write(dma_ctrl, acp_mmio, mmACP_DMA_CNTL_0 + ch_num);
        }

        /* check the channel status bit for some time and return the status */
        while (true) {
                dma_ch_sts = acp_reg_read(acp_mmio, mmACP_DMA_CH_STS);
                if (!(dma_ch_sts & BIT(ch_num))) {
                        /* clear the reset flag after successfully stopping
                        * the dma transfer and break from the loop
                        */
                        dma_ctrl &= ~ACP_DMA_CNTL_0__DMAChRst_MASK;

                        acp_reg_write(dma_ctrl, acp_mmio, mmACP_DMA_CNTL_0
                                                                + ch_num);
                        break;
                }
                if (--count == 0) {
                        pr_err("Failed to stop ACP DMA channel : %d\n", ch_num);
                        return -ETIMEDOUT;
                }
                udelay(100);
        }
        return 0;
}

static void acp_set_sram_bank_state(void __iomem *acp_mmio, u16 bank,
                                        bool power_on)
{
        u32 val, req_reg, sts_reg, sts_reg_mask;
        u32 loops = 1000;

        if (bank < 32) {
                req_reg = mmACP_MEM_SHUT_DOWN_REQ_LO;
                sts_reg = mmACP_MEM_SHUT_DOWN_STS_LO;
                sts_reg_mask = 0xFFFFFFFF;

        } else {
                bank -= 32;
                req_reg = mmACP_MEM_SHUT_DOWN_REQ_HI;
                sts_reg = mmACP_MEM_SHUT_DOWN_STS_HI;
                sts_reg_mask = 0x0000FFFF;
        }

        val = acp_reg_read(acp_mmio, req_reg);
        if (val & (1 << bank)) {
                /* bank is in off state */
                if (power_on == true)
                        /* request to on */
                        val &= ~(1 << bank);
                else
                        /* request to off */
                        return;
        } else {
                /* bank is in on state */
                if (power_on == false)
                        /* request to off */
                        val |= 1 << bank;
                else
                        /* request to on */
                        return;
        }
        acp_reg_write(val, acp_mmio, req_reg);

        while (acp_reg_read(acp_mmio, sts_reg) != sts_reg_mask) {
                if (!loops--) {
                        pr_err("ACP SRAM bank %d state change failed\n", bank);
                        break;
                }
                cpu_relax();
        }
}

/* Initialize and bring ACP hardware to default state. */
static int acp_init(void __iomem *acp_mmio)
{
        u16 bank;
        u32 val, count, sram_pte_offset;

        /* Assert Soft reset of ACP */
        val = acp_reg_read(acp_mmio, mmACP_SOFT_RESET);

        val |= ACP_SOFT_RESET__SoftResetAud_MASK;
        acp_reg_write(val, acp_mmio, mmACP_SOFT_RESET);

        count = ACP_SOFT_RESET_DONE_TIME_OUT_VALUE;
        while (true) {
                val = acp_reg_read(acp_mmio, mmACP_SOFT_RESET);
                if (ACP_SOFT_RESET__SoftResetAudDone_MASK ==
                    (val & ACP_SOFT_RESET__SoftResetAudDone_MASK))
                        break;
                if (--count == 0) {
                        pr_err("Failed to reset ACP\n");
                        return -ETIMEDOUT;
                }
                udelay(100);
        }

        /* Enable clock to ACP and wait until the clock is enabled */
        val = acp_reg_read(acp_mmio, mmACP_CONTROL);
        val = val | ACP_CONTROL__ClkEn_MASK;
        acp_reg_write(val, acp_mmio, mmACP_CONTROL);

        count = ACP_CLOCK_EN_TIME_OUT_VALUE;

        while (true) {
                val = acp_reg_read(acp_mmio, mmACP_STATUS);
                if (val & (u32) 0x1)
                        break;
                if (--count == 0) {
                        pr_err("Failed to reset ACP\n");
                        return -ETIMEDOUT;
                }
                udelay(100);
        }

        /* Deassert the SOFT RESET flags */
        val = acp_reg_read(acp_mmio, mmACP_SOFT_RESET);
        val &= ~ACP_SOFT_RESET__SoftResetAud_MASK;
        acp_reg_write(val, acp_mmio, mmACP_SOFT_RESET);

        /* initiailize Onion control DAGB register */
        acp_reg_write(ACP_ONION_CNTL_DEFAULT, acp_mmio,
                        mmACP_AXI2DAGB_ONION_CNTL);

        /* initiailize Garlic control DAGB registers */
        acp_reg_write(ACP_GARLIC_CNTL_DEFAULT, acp_mmio,
                        mmACP_AXI2DAGB_GARLIC_CNTL);

        sram_pte_offset = ACP_DAGB_GRP_SRAM_BASE_ADDRESS |
                        ACP_DAGB_BASE_ADDR_GRP_1__AXI2DAGBSnoopSel_MASK |
                        ACP_DAGB_BASE_ADDR_GRP_1__AXI2DAGBTargetMemSel_MASK |
                        ACP_DAGB_BASE_ADDR_GRP_1__AXI2DAGBGrpEnable_MASK;
        acp_reg_write(sram_pte_offset,  acp_mmio, mmACP_DAGB_BASE_ADDR_GRP_1);
        acp_reg_write(ACP_PAGE_SIZE_4K_ENABLE, acp_mmio,
                        mmACP_DAGB_PAGE_SIZE_GRP_1);

        acp_reg_write(ACP_SRAM_BASE_ADDRESS, acp_mmio,
                        mmACP_DMA_DESC_BASE_ADDR);

        /* Num of descriptiors in SRAM 0x4, means 256 descriptors;(64 * 4) */
        acp_reg_write(0x4, acp_mmio, mmACP_DMA_DESC_MAX_NUM_DSCR);
        acp_reg_write(ACP_EXTERNAL_INTR_CNTL__DMAIOCMask_MASK,
                acp_mmio, mmACP_EXTERNAL_INTR_CNTL);

       /* When ACP_TILE_P1 is turned on, all SRAM banks get turned on.
        * Now, turn off all of them. This can't be done in 'poweron' of
        * ACP pm domain, as this requires ACP to be initialized.
        */
        for (bank = 1; bank < 48; bank++)
                acp_set_sram_bank_state(acp_mmio, bank, false);

        return 0;
}

/* Deintialize ACP */
static int acp_deinit(void __iomem *acp_mmio)
{
        u32 val;
        u32 count;

        /* Assert Soft reset of ACP */
        val = acp_reg_read(acp_mmio, mmACP_SOFT_RESET);

        val |= ACP_SOFT_RESET__SoftResetAud_MASK;
        acp_reg_write(val, acp_mmio, mmACP_SOFT_RESET);

        count = ACP_SOFT_RESET_DONE_TIME_OUT_VALUE;
        while (true) {
                val = acp_reg_read(acp_mmio, mmACP_SOFT_RESET);
                if (ACP_SOFT_RESET__SoftResetAudDone_MASK ==
                    (val & ACP_SOFT_RESET__SoftResetAudDone_MASK))
                        break;
                if (--count == 0) {
                        pr_err("Failed to reset ACP\n");
                        return -ETIMEDOUT;
                }
                udelay(100);
        }
        /** Disable ACP clock */
        val = acp_reg_read(acp_mmio, mmACP_CONTROL);
        val &= ~ACP_CONTROL__ClkEn_MASK;
        acp_reg_write(val, acp_mmio, mmACP_CONTROL);

        count = ACP_CLOCK_EN_TIME_OUT_VALUE;

        while (true) {
                val = acp_reg_read(acp_mmio, mmACP_STATUS);
                if (!(val & (u32) 0x1))
                        break;
                if (--count == 0) {
                        pr_err("Failed to reset ACP\n");
                        return -ETIMEDOUT;
                }
                udelay(100);
        }
        return 0;
}

/* ACP DMA irq handler routine for playback, capture usecases */
static irqreturn_t dma_irq_handler(int irq, void *arg)
{
        u16 dscr_idx;
        u32 intr_flag, ext_intr_status;
        struct audio_drv_data *irq_data;
        void __iomem *acp_mmio;
        struct device *dev = arg;
        bool valid_irq = false;

        irq_data = dev_get_drvdata(dev);
        acp_mmio = irq_data->acp_mmio;

        ext_intr_status = acp_reg_read(acp_mmio, mmACP_EXTERNAL_INTR_STAT);
        intr_flag = (((ext_intr_status &
                      ACP_EXTERNAL_INTR_STAT__DMAIOCStat_MASK) >>
                     ACP_EXTERNAL_INTR_STAT__DMAIOCStat__SHIFT));

        if ((intr_flag & BIT(ACP_TO_I2S_DMA_CH_NUM)) != 0) {
                valid_irq = true;
                if (acp_reg_read(acp_mmio, mmACP_DMA_CUR_DSCR_13) ==
                                PLAYBACK_START_DMA_DESCR_CH13)
                        dscr_idx = PLAYBACK_START_DMA_DESCR_CH12;
                else
                        dscr_idx = PLAYBACK_END_DMA_DESCR_CH12;
                config_acp_dma_channel(acp_mmio, SYSRAM_TO_ACP_CH_NUM, dscr_idx,
                                       1, 0);
                acp_dma_start(acp_mmio, SYSRAM_TO_ACP_CH_NUM, false);

                snd_pcm_period_elapsed(irq_data->play_stream);

                acp_reg_write((intr_flag & BIT(ACP_TO_I2S_DMA_CH_NUM)) << 16,
                                acp_mmio, mmACP_EXTERNAL_INTR_STAT);
        }

        if ((intr_flag & BIT(I2S_TO_ACP_DMA_CH_NUM)) != 0) {
                valid_irq = true;
                if (acp_reg_read(acp_mmio, mmACP_DMA_CUR_DSCR_15) ==
                                CAPTURE_START_DMA_DESCR_CH15)
                        dscr_idx = CAPTURE_END_DMA_DESCR_CH14;
                else
                        dscr_idx = CAPTURE_START_DMA_DESCR_CH14;
                config_acp_dma_channel(acp_mmio, ACP_TO_SYSRAM_CH_NUM, dscr_idx,
                                       1, 0);
                acp_dma_start(acp_mmio, ACP_TO_SYSRAM_CH_NUM, false);

                acp_reg_write((intr_flag & BIT(I2S_TO_ACP_DMA_CH_NUM)) << 16,
                                acp_mmio, mmACP_EXTERNAL_INTR_STAT);
        }

        if ((intr_flag & BIT(ACP_TO_SYSRAM_CH_NUM)) != 0) {
                valid_irq = true;
                snd_pcm_period_elapsed(irq_data->capture_stream);
                acp_reg_write((intr_flag & BIT(ACP_TO_SYSRAM_CH_NUM)) << 16,
                                acp_mmio, mmACP_EXTERNAL_INTR_STAT);
        }

        if (valid_irq)
                return IRQ_HANDLED;
        else
                return IRQ_NONE;
}

static int acp_dma_open(struct snd_pcm_substream *substream)
{
        u16 bank;
        int ret = 0;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *prtd = substream->private_data;
        struct audio_drv_data *intr_data = dev_get_drvdata(prtd->platform->dev);

        struct audio_substream_data *adata =
                kzalloc(sizeof(struct audio_substream_data), GFP_KERNEL);
        if (adata == NULL)
                return -ENOMEM;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                runtime->hw = acp_pcm_hardware_playback;
        else
                runtime->hw = acp_pcm_hardware_capture;

        ret = snd_pcm_hw_constraint_integer(runtime,
                                            SNDRV_PCM_HW_PARAM_PERIODS);
        if (ret < 0) {
                dev_err(prtd->platform->dev, "set integer constraint failed\n");
                kfree(adata);
                return ret;
        }

        adata->acp_mmio = intr_data->acp_mmio;
        runtime->private_data = adata;

        /* Enable ACP irq, when neither playback or capture streams are
         * active by the time when a new stream is being opened.
         * This enablement is not required for another stream, if current
         * stream is not closed
        */
        if (!intr_data->play_stream && !intr_data->capture_stream)
                acp_reg_write(1, adata->acp_mmio, mmACP_EXTERNAL_INTR_ENB);

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                intr_data->play_stream = substream;
                for (bank = 1; bank <= 4; bank++)
                        acp_set_sram_bank_state(intr_data->acp_mmio, bank,
                                                true);
        } else {
                intr_data->capture_stream = substream;
                for (bank = 5; bank <= 8; bank++)
                        acp_set_sram_bank_state(intr_data->acp_mmio, bank,
                                                true);
        }

        return 0;
}

static int acp_dma_hw_params(struct snd_pcm_substream *substream,
                             struct snd_pcm_hw_params *params)
{
        int status;
        uint64_t size;
        struct snd_dma_buffer *dma_buffer;
        struct page *pg;
        struct snd_pcm_runtime *runtime;
        struct audio_substream_data *rtd;

        dma_buffer = &substream->dma_buffer;

        runtime = substream->runtime;
        rtd = runtime->private_data;

        if (WARN_ON(!rtd))
                return -EINVAL;

        size = params_buffer_bytes(params);
        status = snd_pcm_lib_malloc_pages(substream, size);
        if (status < 0)
                return status;

        memset(substream->runtime->dma_area, 0, params_buffer_bytes(params));
        pg = virt_to_page(substream->dma_buffer.area);

        if (pg != NULL) {
                acp_set_sram_bank_state(rtd->acp_mmio, 0, true);
                /* Save for runtime private data */
                rtd->pg = pg;
                rtd->order = get_order(size);

                /* Fill the page table entries in ACP SRAM */
                rtd->pg = pg;
                rtd->size = size;
                rtd->num_of_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
                rtd->direction = substream->stream;

                config_acp_dma(rtd->acp_mmio, rtd);
                status = 0;
        } else {
                status = -ENOMEM;
        }
        return status;
}

static int acp_dma_hw_free(struct snd_pcm_substream *substream)
{
        return snd_pcm_lib_free_pages(substream);
}

static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
{
        u16 dscr;
        u32 mul, dma_config, period_bytes;
        u32 pos = 0;

        struct snd_pcm_runtime *runtime = substream->runtime;
        struct audio_substream_data *rtd = runtime->private_data;

        period_bytes = frames_to_bytes(runtime, runtime->period_size);
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                dscr = acp_reg_read(rtd->acp_mmio, mmACP_DMA_CUR_DSCR_13);

                if (dscr == PLAYBACK_START_DMA_DESCR_CH13)
                        mul = 0;
                else
                        mul = 1;
                pos =  (mul * period_bytes);
        } else {
                dma_config = acp_reg_read(rtd->acp_mmio, mmACP_DMA_CNTL_14);
                if (dma_config != 0) {
                        dscr = acp_reg_read(rtd->acp_mmio,
                                                mmACP_DMA_CUR_DSCR_14);
                        if (dscr == CAPTURE_START_DMA_DESCR_CH14)
                                mul = 1;
                        else
                                mul = 2;
                        pos = (mul * period_bytes);
                }

                if (pos >= (2 * period_bytes))
                        pos = 0;

        }
        return bytes_to_frames(runtime, pos);
}

static int acp_dma_mmap(struct snd_pcm_substream *substream,
                        struct vm_area_struct *vma)
{
        return snd_pcm_lib_default_mmap(substream, vma);
}

static int acp_dma_prepare(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct audio_substream_data *rtd = runtime->private_data;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                config_acp_dma_channel(rtd->acp_mmio, SYSRAM_TO_ACP_CH_NUM,
                                        PLAYBACK_START_DMA_DESCR_CH12,
                                        NUM_DSCRS_PER_CHANNEL, 0);
                config_acp_dma_channel(rtd->acp_mmio, ACP_TO_I2S_DMA_CH_NUM,
                                        PLAYBACK_START_DMA_DESCR_CH13,
                                        NUM_DSCRS_PER_CHANNEL, 0);
                /* Fill ACP SRAM (2 periods) with zeros from System RAM
                 * which is zero-ed in hw_params
                */
                acp_dma_start(rtd->acp_mmio, SYSRAM_TO_ACP_CH_NUM, false);

                /* ACP SRAM (2 periods of buffer size) is intially filled with
                 * zeros. Before rendering starts, 2nd half of SRAM will be
                 * filled with valid audio data DMA'ed from first half of system
                 * RAM and 1st half of SRAM will be filled with Zeros. This is
                 * the initial scenario when redering starts from SRAM. Later
                 * on, 2nd half of system memory will be DMA'ed to 1st half of
                 * SRAM, 1st half of system memory will be DMA'ed to 2nd half of
                 * SRAM in ping-pong way till rendering stops.
                */
                config_acp_dma_channel(rtd->acp_mmio, SYSRAM_TO_ACP_CH_NUM,
                                        PLAYBACK_START_DMA_DESCR_CH12,
                                        1, 0);
        } else {
                config_acp_dma_channel(rtd->acp_mmio, ACP_TO_SYSRAM_CH_NUM,
                                        CAPTURE_START_DMA_DESCR_CH14,
                                        NUM_DSCRS_PER_CHANNEL, 0);
                config_acp_dma_channel(rtd->acp_mmio, I2S_TO_ACP_DMA_CH_NUM,
                                        CAPTURE_START_DMA_DESCR_CH15,
                                        NUM_DSCRS_PER_CHANNEL, 0);
        }
        return 0;
}

static int acp_dma_trigger(struct snd_pcm_substream *substream, int cmd)
{
        int ret;
        u32 loops = 1000;

        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *prtd = substream->private_data;
        struct audio_substream_data *rtd = runtime->private_data;

        if (!rtd)
                return -EINVAL;
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
        case SNDRV_PCM_TRIGGER_RESUME:
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                        acp_dma_start(rtd->acp_mmio,
                                                SYSRAM_TO_ACP_CH_NUM, false);
                        while (acp_reg_read(rtd->acp_mmio, mmACP_DMA_CH_STS) &
                                                BIT(SYSRAM_TO_ACP_CH_NUM)) {
                                if (!loops--) {
                                        dev_err(prtd->platform->dev,
                                                "acp dma start timeout\n");
                                        return -ETIMEDOUT;
                                }
                                cpu_relax();
                        }

                        acp_dma_start(rtd->acp_mmio,
                                        ACP_TO_I2S_DMA_CH_NUM, true);

                } else {
                        acp_dma_start(rtd->acp_mmio,
                                            I2S_TO_ACP_DMA_CH_NUM, true);
                }
                ret = 0;
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        case SNDRV_PCM_TRIGGER_SUSPEND:
                /* Need to stop only circular DMA channels :
                 * ACP_TO_I2S_DMA_CH_NUM / I2S_TO_ACP_DMA_CH_NUM. Non-circular
                 * channels will stopped automatically after its transfer
                 * completes : SYSRAM_TO_ACP_CH_NUM / ACP_TO_SYSRAM_CH_NUM
                 */
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                        ret = acp_dma_stop(rtd->acp_mmio,
                                        ACP_TO_I2S_DMA_CH_NUM);
                else
                        ret = acp_dma_stop(rtd->acp_mmio,
                                        I2S_TO_ACP_DMA_CH_NUM);
                break;
        default:
                ret = -EINVAL;

        }
        return ret;
}

static int acp_dma_new(struct snd_soc_pcm_runtime *rtd)
{
        return snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
                                                        SNDRV_DMA_TYPE_DEV,
                                                        NULL, MIN_BUFFER,
                                                        MAX_BUFFER);
}

static int acp_dma_close(struct snd_pcm_substream *substream)
{
        u16 bank;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct audio_substream_data *rtd = runtime->private_data;
        struct snd_soc_pcm_runtime *prtd = substream->private_data;
        struct audio_drv_data *adata = dev_get_drvdata(prtd->platform->dev);

        kfree(rtd);

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                adata->play_stream = NULL;
                for (bank = 1; bank <= 4; bank++)
                        acp_set_sram_bank_state(adata->acp_mmio, bank,
                                                false);
        } else {
                adata->capture_stream = NULL;
                for (bank = 5; bank <= 8; bank++)
                        acp_set_sram_bank_state(adata->acp_mmio, bank,
                                                false);
        }

        /* Disable ACP irq, when the current stream is being closed and
         * another stream is also not active.
        */
        if (!adata->play_stream && !adata->capture_stream)
                acp_reg_write(0, adata->acp_mmio, mmACP_EXTERNAL_INTR_ENB);

        return 0;
}

static struct snd_pcm_ops acp_dma_ops = {
        .open = acp_dma_open,
        .close = acp_dma_close,
        .ioctl = snd_pcm_lib_ioctl,
        .hw_params = acp_dma_hw_params,
        .hw_free = acp_dma_hw_free,
        .trigger = acp_dma_trigger,
        .pointer = acp_dma_pointer,
        .mmap = acp_dma_mmap,
        .prepare = acp_dma_prepare,
};

static struct snd_soc_platform_driver acp_asoc_platform = {
        .ops = &acp_dma_ops,
        .pcm_new = acp_dma_new,
};

static int acp_audio_probe(struct platform_device *pdev)
{
        int status;
        struct audio_drv_data *audio_drv_data;
        struct resource *res;

        audio_drv_data = devm_kzalloc(&pdev->dev, sizeof(struct audio_drv_data),
                                        GFP_KERNEL);
        if (audio_drv_data == NULL)
                return -ENOMEM;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        audio_drv_data->acp_mmio = devm_ioremap_resource(&pdev->dev, res);

        /* The following members gets populated in device 'open'
         * function. Till then interrupts are disabled in 'acp_init'
         * and device doesn't generate any interrupts.
         */

        audio_drv_data->play_stream = NULL;
        audio_drv_data->capture_stream = NULL;

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (!res) {
                dev_err(&pdev->dev, "IORESOURCE_IRQ FAILED\n");
                return -ENODEV;
        }

        status = devm_request_irq(&pdev->dev, res->start, dma_irq_handler,
                                        0, "ACP_IRQ", &pdev->dev);
        if (status) {
                dev_err(&pdev->dev, "ACP IRQ request failed\n");
                return status;
        }

        dev_set_drvdata(&pdev->dev, audio_drv_data);

        /* Initialize the ACP */
        acp_init(audio_drv_data->acp_mmio);

        status = snd_soc_register_platform(&pdev->dev, &acp_asoc_platform);
        if (status != 0) {
                dev_err(&pdev->dev, "Fail to register ALSA platform device\n");
                return status;
        }

        pm_runtime_set_autosuspend_delay(&pdev->dev, 10000);
        pm_runtime_use_autosuspend(&pdev->dev);
        pm_runtime_enable(&pdev->dev);

        return status;
}

static int acp_audio_remove(struct platform_device *pdev)
{
        struct audio_drv_data *adata = dev_get_drvdata(&pdev->dev);

        acp_deinit(adata->acp_mmio);
        snd_soc_unregister_platform(&pdev->dev);
        pm_runtime_disable(&pdev->dev);

        return 0;
}

static int acp_pcm_resume(struct device *dev)
{
        u16 bank;
        struct audio_drv_data *adata = dev_get_drvdata(dev);

        acp_init(adata->acp_mmio);

        if (adata->play_stream && adata->play_stream->runtime) {
                for (bank = 1; bank <= 4; bank++)
                        acp_set_sram_bank_state(adata->acp_mmio, bank,
                                                true);
                config_acp_dma(adata->acp_mmio,
                                adata->play_stream->runtime->private_data);
        }
        if (adata->capture_stream && adata->capture_stream->runtime) {
                for (bank = 5; bank <= 8; bank++)
                        acp_set_sram_bank_state(adata->acp_mmio, bank,
                                                true);
                config_acp_dma(adata->acp_mmio,
                                adata->capture_stream->runtime->private_data);

        }
        acp_reg_write(1, adata->acp_mmio, mmACP_EXTERNAL_INTR_ENB);
        return 0;
}

static int acp_pcm_runtime_suspend(struct device *dev)
{
        struct audio_drv_data *adata = dev_get_drvdata(dev);

        acp_deinit(adata->acp_mmio);
        acp_reg_write(0, adata->acp_mmio, mmACP_EXTERNAL_INTR_ENB);
        return 0;
}

static int acp_pcm_runtime_resume(struct device *dev)
{
        struct audio_drv_data *adata = dev_get_drvdata(dev);

        acp_init(adata->acp_mmio);
        acp_reg_write(1, adata->acp_mmio, mmACP_EXTERNAL_INTR_ENB);
        return 0;
}

static const struct dev_pm_ops acp_pm_ops = {
        .resume = acp_pcm_resume,
        .runtime_suspend = acp_pcm_runtime_suspend,
        .runtime_resume = acp_pcm_runtime_resume,
};

static struct platform_driver acp_dma_driver = {
        .probe = acp_audio_probe,
        .remove = acp_audio_remove,
        .driver = {
                .name = "acp_audio_dma",
                .pm = &acp_pm_ops,
        },
};

module_platform_driver(acp_dma_driver);

MODULE_AUTHOR("Maruthi.Bayyavarapu@amd.com");
MODULE_DESCRIPTION("AMD ACP PCM Driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:acp-dma-audio");