/*
 * Renesas R-Car Audio DMAC support
 *
 * Copyright (C) 2015 Renesas Electronics Corp.
 * Copyright (c) 2015 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/delay.h>
#include <linux/of_dma.h>
#include "rsnd.h"

/*
 * Audio DMAC peri peri register
 */
#define PDMASAR         0x00
#define PDMADAR         0x04
#define PDMACHCR        0x0c

/* PDMACHCR */
#define PDMACHCR_DE             (1 << 0)


struct rsnd_dmaen {
        struct dma_chan         *chan;
        dma_cookie_t            cookie;
        unsigned int            dma_len;
};

struct rsnd_dmapp {
        int                     dmapp_id;
        u32                     chcr;
};

struct rsnd_dma {
        struct rsnd_mod         mod;
        struct rsnd_mod         *mod_from;
        struct rsnd_mod         *mod_to;
        dma_addr_t              src_addr;
        dma_addr_t              dst_addr;
        union {
                struct rsnd_dmaen en;
                struct rsnd_dmapp pp;
        } dma;
};

struct rsnd_dma_ctrl {
        void __iomem *base;
        int dmaen_num;
        int dmapp_num;
};

#define rsnd_priv_to_dmac(p)    ((struct rsnd_dma_ctrl *)(p)->dma)
#define rsnd_mod_to_dma(_mod) container_of((_mod), struct rsnd_dma, mod)
#define rsnd_dma_to_dmaen(dma)  (&(dma)->dma.en)
#define rsnd_dma_to_dmapp(dma)  (&(dma)->dma.pp)

/* for DEBUG */
static struct rsnd_mod_ops mem_ops = {
        .name = "mem",
};

static struct rsnd_mod mem = {
};

/*
 *              Audio DMAC
 */
static void __rsnd_dmaen_complete(struct rsnd_mod *mod,
                                  struct rsnd_dai_stream *io)
{
        if (rsnd_io_is_working(io))
                rsnd_dai_period_elapsed(io);
}

static void rsnd_dmaen_complete(void *data)
{
        struct rsnd_mod *mod = data;

        rsnd_mod_interrupt(mod, __rsnd_dmaen_complete);
}

static struct dma_chan *rsnd_dmaen_request_channel(struct rsnd_dai_stream *io,
                                                   struct rsnd_mod *mod_from,
                                                   struct rsnd_mod *mod_to)
{
        if ((!mod_from && !mod_to) ||
            (mod_from && mod_to))
                return NULL;

        if (mod_from)
                return rsnd_mod_dma_req(io, mod_from);
        else
                return rsnd_mod_dma_req(io, mod_to);
}

static int rsnd_dmaen_stop(struct rsnd_mod *mod,
                           struct rsnd_dai_stream *io,
                           struct rsnd_priv *priv)
{
        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
        struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);

        if (dmaen->chan)
                dmaengine_terminate_all(dmaen->chan);

        return 0;
}

static int rsnd_dmaen_nolock_stop(struct rsnd_mod *mod,
                                   struct rsnd_dai_stream *io,
                                   struct rsnd_priv *priv)
{
        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
        struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);

        /*
         * DMAEngine release uses mutex lock.
         * Thus, it shouldn't be called under spinlock.
         * Let's call it under nolock_start
         */
        if (dmaen->chan)
                dma_release_channel(dmaen->chan);

        dmaen->chan = NULL;

        return 0;
}

static int rsnd_dmaen_nolock_start(struct rsnd_mod *mod,
                            struct rsnd_dai_stream *io,
                            struct rsnd_priv *priv)
{
        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
        struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
        struct device *dev = rsnd_priv_to_dev(priv);

        if (dmaen->chan) {
                dev_err(dev, "it already has dma channel\n");
                return -EIO;
        }

        /*
         * DMAEngine request uses mutex lock.
         * Thus, it shouldn't be called under spinlock.
         * Let's call it under nolock_start
         */
        dmaen->chan = rsnd_dmaen_request_channel(io,
                                                 dma->mod_from,
                                                 dma->mod_to);
        if (IS_ERR_OR_NULL(dmaen->chan)) {
                dmaen->chan = NULL;
                dev_err(dev, "can't get dma channel\n");
                return -EIO;
        }

        return 0;
}

static int rsnd_dmaen_start(struct rsnd_mod *mod,
                            struct rsnd_dai_stream *io,
                            struct rsnd_priv *priv)
{
        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
        struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
        struct snd_pcm_substream *substream = io->substream;
        struct device *dev = rsnd_priv_to_dev(priv);
        struct dma_async_tx_descriptor *desc;
        struct dma_slave_config cfg = {};
        int is_play = rsnd_io_is_play(io);
        int ret;

        cfg.direction   = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
        cfg.src_addr    = dma->src_addr;
        cfg.dst_addr    = dma->dst_addr;
        cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;

        dev_dbg(dev, "%s[%d] %pad -> %pad\n",
                rsnd_mod_name(mod), rsnd_mod_id(mod),
                &cfg.src_addr, &cfg.dst_addr);

        ret = dmaengine_slave_config(dmaen->chan, &cfg);
        if (ret < 0)
                return ret;

        desc = dmaengine_prep_dma_cyclic(dmaen->chan,
                                         substream->runtime->dma_addr,
                                         snd_pcm_lib_buffer_bytes(substream),
                                         snd_pcm_lib_period_bytes(substream),
                                         is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
                                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

        if (!desc) {
                dev_err(dev, "dmaengine_prep_slave_sg() fail\n");
                return -EIO;
        }

        desc->callback          = rsnd_dmaen_complete;
        desc->callback_param    = rsnd_mod_get(dma);

        dmaen->dma_len          = snd_pcm_lib_buffer_bytes(substream);

        dmaen->cookie = dmaengine_submit(desc);
        if (dmaen->cookie < 0) {
                dev_err(dev, "dmaengine_submit() fail\n");
                return -EIO;
        }

        dma_async_issue_pending(dmaen->chan);

        return 0;
}

struct dma_chan *rsnd_dma_request_channel(struct device_node *of_node,
                                          struct rsnd_mod *mod, char *name)
{
        struct dma_chan *chan = NULL;
        struct device_node *np;
        int i = 0;

        for_each_child_of_node(of_node, np) {
                if (i == rsnd_mod_id(mod) && (!chan))
                        chan = of_dma_request_slave_channel(np, name);
                i++;
        }

        /* It should call of_node_put(), since, it is rsnd_xxx_of_node() */
        of_node_put(of_node);

        return chan;
}

static int rsnd_dmaen_attach(struct rsnd_dai_stream *io,
                           struct rsnd_dma *dma,
                           struct rsnd_mod *mod_from, struct rsnd_mod *mod_to)
{
        struct rsnd_priv *priv = rsnd_io_to_priv(io);
        struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
        struct dma_chan *chan;

        /* try to get DMAEngine channel */
        chan = rsnd_dmaen_request_channel(io, mod_from, mod_to);
        if (IS_ERR_OR_NULL(chan)) {
                /*
                 * DMA failed. try to PIO mode
                 * see
                 *      rsnd_ssi_fallback()
                 *      rsnd_rdai_continuance_probe()
                 */
                return -EAGAIN;
        }

        dma_release_channel(chan);

        dmac->dmaen_num++;

        return 0;
}

static int rsnd_dmaen_pointer(struct rsnd_mod *mod,
                              struct rsnd_dai_stream *io,
                              snd_pcm_uframes_t *pointer)
{
        struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
        struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
        struct dma_tx_state state;
        enum dma_status status;
        unsigned int pos = 0;

        status = dmaengine_tx_status(dmaen->chan, dmaen->cookie, &state);
        if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
                if (state.residue > 0 && state.residue <= dmaen->dma_len)
                        pos = dmaen->dma_len - state.residue;
        }
        *pointer = bytes_to_frames(runtime, pos);

        return 0;
}

static struct rsnd_mod_ops rsnd_dmaen_ops = {
        .name   = "audmac",
        .nolock_start = rsnd_dmaen_nolock_start,
        .nolock_stop  = rsnd_dmaen_nolock_stop,
        .start  = rsnd_dmaen_start,
        .stop   = rsnd_dmaen_stop,
        .pointer= rsnd_dmaen_pointer,
};

/*
 *              Audio DMAC peri peri
 */
static const u8 gen2_id_table_ssiu[] = {
        0x00, /* SSI00 */
        0x04, /* SSI10 */
        0x08, /* SSI20 */
        0x0c, /* SSI3  */
        0x0d, /* SSI4  */
        0x0e, /* SSI5  */
        0x0f, /* SSI6  */
        0x10, /* SSI7  */
        0x11, /* SSI8  */
        0x12, /* SSI90 */
};
static const u8 gen2_id_table_scu[] = {
        0x2d, /* SCU_SRCI0 */
        0x2e, /* SCU_SRCI1 */
        0x2f, /* SCU_SRCI2 */
        0x30, /* SCU_SRCI3 */
        0x31, /* SCU_SRCI4 */
        0x32, /* SCU_SRCI5 */
        0x33, /* SCU_SRCI6 */
        0x34, /* SCU_SRCI7 */
        0x35, /* SCU_SRCI8 */
        0x36, /* SCU_SRCI9 */
};
static const u8 gen2_id_table_cmd[] = {
        0x37, /* SCU_CMD0 */
        0x38, /* SCU_CMD1 */
};

static u32 rsnd_dmapp_get_id(struct rsnd_dai_stream *io,
                             struct rsnd_mod *mod)
{
        struct rsnd_mod *ssi = rsnd_io_to_mod_ssi(io);
        struct rsnd_mod *src = rsnd_io_to_mod_src(io);
        struct rsnd_mod *dvc = rsnd_io_to_mod_dvc(io);
        const u8 *entry = NULL;
        int id = rsnd_mod_id(mod);
        int size = 0;

        if (mod == ssi) {
                entry = gen2_id_table_ssiu;
                size = ARRAY_SIZE(gen2_id_table_ssiu);
        } else if (mod == src) {
                entry = gen2_id_table_scu;
                size = ARRAY_SIZE(gen2_id_table_scu);
        } else if (mod == dvc) {
                entry = gen2_id_table_cmd;
                size = ARRAY_SIZE(gen2_id_table_cmd);
        }

        if ((!entry) || (size <= id)) {
                struct device *dev = rsnd_priv_to_dev(rsnd_io_to_priv(io));

                dev_err(dev, "unknown connection (%s[%d])\n",
                        rsnd_mod_name(mod), rsnd_mod_id(mod));

                /* use non-prohibited SRS number as error */
                return 0x00; /* SSI00 */
        }

        return entry[id];
}

static u32 rsnd_dmapp_get_chcr(struct rsnd_dai_stream *io,
                               struct rsnd_mod *mod_from,
                               struct rsnd_mod *mod_to)
{
        return  (rsnd_dmapp_get_id(io, mod_from) << 24) +
                (rsnd_dmapp_get_id(io, mod_to) << 16);
}

#define rsnd_dmapp_addr(dmac, dma, reg) \
        (dmac->base + 0x20 + reg + \
         (0x10 * rsnd_dma_to_dmapp(dma)->dmapp_id))
static void rsnd_dmapp_write(struct rsnd_dma *dma, u32 data, u32 reg)
{
        struct rsnd_mod *mod = rsnd_mod_get(dma);
        struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
        struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
        struct device *dev = rsnd_priv_to_dev(priv);

        dev_dbg(dev, "w %p : %08x\n", rsnd_dmapp_addr(dmac, dma, reg), data);

        iowrite32(data, rsnd_dmapp_addr(dmac, dma, reg));
}

static u32 rsnd_dmapp_read(struct rsnd_dma *dma, u32 reg)
{
        struct rsnd_mod *mod = rsnd_mod_get(dma);
        struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
        struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);

        return ioread32(rsnd_dmapp_addr(dmac, dma, reg));
}

static void rsnd_dmapp_bset(struct rsnd_dma *dma, u32 data, u32 mask, u32 reg)
{
        struct rsnd_mod *mod = rsnd_mod_get(dma);
        struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
        struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
        void __iomem *addr = rsnd_dmapp_addr(dmac, dma, reg);
        u32 val = ioread32(addr);

        val &= ~mask;
        val |= (data & mask);

        iowrite32(val, addr);
}

static int rsnd_dmapp_stop(struct rsnd_mod *mod,
                           struct rsnd_dai_stream *io,
                           struct rsnd_priv *priv)
{
        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
        int i;

        rsnd_dmapp_bset(dma, 0,  PDMACHCR_DE, PDMACHCR);

        for (i = 0; i < 1024; i++) {
                if (0 == (rsnd_dmapp_read(dma, PDMACHCR) & PDMACHCR_DE))
                        return 0;
                udelay(1);
        }

        return -EIO;
}

static int rsnd_dmapp_start(struct rsnd_mod *mod,
                            struct rsnd_dai_stream *io,
                            struct rsnd_priv *priv)
{
        struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
        struct rsnd_dmapp *dmapp = rsnd_dma_to_dmapp(dma);

        rsnd_dmapp_write(dma, dma->src_addr,    PDMASAR);
        rsnd_dmapp_write(dma, dma->dst_addr,    PDMADAR);
        rsnd_dmapp_write(dma, dmapp->chcr,      PDMACHCR);

        return 0;
}

static int rsnd_dmapp_attach(struct rsnd_dai_stream *io,
                             struct rsnd_dma *dma,
                             struct rsnd_mod *mod_from, struct rsnd_mod *mod_to)
{
        struct rsnd_dmapp *dmapp = rsnd_dma_to_dmapp(dma);
        struct rsnd_priv *priv = rsnd_io_to_priv(io);
        struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
        struct device *dev = rsnd_priv_to_dev(priv);

        dmapp->dmapp_id = dmac->dmapp_num;
        dmapp->chcr = rsnd_dmapp_get_chcr(io, mod_from, mod_to) | PDMACHCR_DE;

        dmac->dmapp_num++;

        dev_dbg(dev, "id/src/dst/chcr = %d/%pad/%pad/%08x\n",
                dmapp->dmapp_id, &dma->src_addr, &dma->dst_addr, dmapp->chcr);

        return 0;
}

static struct rsnd_mod_ops rsnd_dmapp_ops = {
        .name   = "audmac-pp",
        .start  = rsnd_dmapp_start,
        .stop   = rsnd_dmapp_stop,
        .quit   = rsnd_dmapp_stop,
};

/*
 *              Common DMAC Interface
 */

/*
 *      DMA read/write register offset
 *
 *      RSND_xxx_I_N    for Audio DMAC input
 *      RSND_xxx_O_N    for Audio DMAC output
 *      RSND_xxx_I_P    for Audio DMAC peri peri input
 *      RSND_xxx_O_P    for Audio DMAC peri peri output
 *
 *      ex) R-Car H2 case
 *            mod        / DMAC in    / DMAC out   / DMAC PP in / DMAC pp out
 *      SSI : 0xec541000 / 0xec241008 / 0xec24100c
 *      SSIU: 0xec541000 / 0xec100000 / 0xec100000 / 0xec400000 / 0xec400000
 *      SCU : 0xec500000 / 0xec000000 / 0xec004000 / 0xec300000 / 0xec304000
 *      CMD : 0xec500000 /            / 0xec008000                0xec308000
 */
#define RDMA_SSI_I_N(addr, i)   (addr ##_reg - 0x00300000 + (0x40 * i) + 0x8)
#define RDMA_SSI_O_N(addr, i)   (addr ##_reg - 0x00300000 + (0x40 * i) + 0xc)

#define RDMA_SSIU_I_N(addr, i)  (addr ##_reg - 0x00441000 + (0x1000 * i))
#define RDMA_SSIU_O_N(addr, i)  (addr ##_reg - 0x00441000 + (0x1000 * i))

#define RDMA_SSIU_I_P(addr, i)  (addr ##_reg - 0x00141000 + (0x1000 * i))
#define RDMA_SSIU_O_P(addr, i)  (addr ##_reg - 0x00141000 + (0x1000 * i))

#define RDMA_SRC_I_N(addr, i)   (addr ##_reg - 0x00500000 + (0x400 * i))
#define RDMA_SRC_O_N(addr, i)   (addr ##_reg - 0x004fc000 + (0x400 * i))

#define RDMA_SRC_I_P(addr, i)   (addr ##_reg - 0x00200000 + (0x400 * i))
#define RDMA_SRC_O_P(addr, i)   (addr ##_reg - 0x001fc000 + (0x400 * i))

#define RDMA_CMD_O_N(addr, i)   (addr ##_reg - 0x004f8000 + (0x400 * i))
#define RDMA_CMD_O_P(addr, i)   (addr ##_reg - 0x001f8000 + (0x400 * i))

static dma_addr_t
rsnd_gen2_dma_addr(struct rsnd_dai_stream *io,
                   struct rsnd_mod *mod,
                   int is_play, int is_from)
{
        struct rsnd_priv *priv = rsnd_io_to_priv(io);
        struct device *dev = rsnd_priv_to_dev(priv);
        phys_addr_t ssi_reg = rsnd_gen_get_phy_addr(priv, RSND_GEN2_SSI);
        phys_addr_t src_reg = rsnd_gen_get_phy_addr(priv, RSND_GEN2_SCU);
        int is_ssi = !!(rsnd_io_to_mod_ssi(io) == mod);
        int use_src = !!rsnd_io_to_mod_src(io);
        int use_cmd = !!rsnd_io_to_mod_dvc(io) ||
                      !!rsnd_io_to_mod_mix(io) ||
                      !!rsnd_io_to_mod_ctu(io);
        int id = rsnd_mod_id(mod);
        struct dma_addr {
                dma_addr_t out_addr;
                dma_addr_t in_addr;
        } dma_addrs[3][2][3] = {
                /* SRC */
                /* Capture */
                {{{ 0,                          0 },
                  { RDMA_SRC_O_N(src, id),      RDMA_SRC_I_P(src, id) },
                  { RDMA_CMD_O_N(src, id),      RDMA_SRC_I_P(src, id) } },
                 /* Playback */
                 {{ 0,                          0, },
                  { RDMA_SRC_O_P(src, id),      RDMA_SRC_I_N(src, id) },
                  { RDMA_CMD_O_P(src, id),      RDMA_SRC_I_N(src, id) } }
                },
                /* SSI */
                /* Capture */
                {{{ RDMA_SSI_O_N(ssi, id),      0 },
                  { RDMA_SSIU_O_P(ssi, id),     0 },
                  { RDMA_SSIU_O_P(ssi, id),     0 } },
                 /* Playback */
                 {{ 0,                          RDMA_SSI_I_N(ssi, id) },
                  { 0,                          RDMA_SSIU_I_P(ssi, id) },
                  { 0,                          RDMA_SSIU_I_P(ssi, id) } }
                },
                /* SSIU */
                /* Capture */
                {{{ RDMA_SSIU_O_N(ssi, id),     0 },
                  { RDMA_SSIU_O_P(ssi, id),     0 },
                  { RDMA_SSIU_O_P(ssi, id),     0 } },
                 /* Playback */
                 {{ 0,                          RDMA_SSIU_I_N(ssi, id) },
                  { 0,                          RDMA_SSIU_I_P(ssi, id) },
                  { 0,                          RDMA_SSIU_I_P(ssi, id) } } },
        };

        /* it shouldn't happen */
        if (use_cmd && !use_src)
                dev_err(dev, "DVC is selected without SRC\n");

        /* use SSIU or SSI ? */
        if (is_ssi && rsnd_ssi_use_busif(io))
                is_ssi++;

        return (is_from) ?
                dma_addrs[is_ssi][is_play][use_src + use_cmd].out_addr :
                dma_addrs[is_ssi][is_play][use_src + use_cmd].in_addr;
}

static dma_addr_t rsnd_dma_addr(struct rsnd_dai_stream *io,
                                struct rsnd_mod *mod,
                                int is_play, int is_from)
{
        struct rsnd_priv *priv = rsnd_io_to_priv(io);

        /*
         * gen1 uses default DMA addr
         */
        if (rsnd_is_gen1(priv))
                return 0;

        if (!mod)
                return 0;

        return rsnd_gen2_dma_addr(io, mod, is_play, is_from);
}

#define MOD_MAX (RSND_MOD_MAX + 1) /* +Memory */
static void rsnd_dma_of_path(struct rsnd_mod *this,
                             struct rsnd_dai_stream *io,
                             int is_play,
                             struct rsnd_mod **mod_from,
                             struct rsnd_mod **mod_to)
{
        struct rsnd_mod *ssi = rsnd_io_to_mod_ssi(io);
        struct rsnd_mod *src = rsnd_io_to_mod_src(io);
        struct rsnd_mod *ctu = rsnd_io_to_mod_ctu(io);
        struct rsnd_mod *mix = rsnd_io_to_mod_mix(io);
        struct rsnd_mod *dvc = rsnd_io_to_mod_dvc(io);
        struct rsnd_mod *mod[MOD_MAX];
        struct rsnd_mod *mod_start, *mod_end;
        struct rsnd_priv *priv = rsnd_mod_to_priv(this);
        struct device *dev = rsnd_priv_to_dev(priv);
        int nr, i, idx;

        if (!ssi)
                return;

        nr = 0;
        for (i = 0; i < MOD_MAX; i++) {
                mod[i] = NULL;
                nr += !!rsnd_io_to_mod(io, i);
        }

        /*
         * [S] -*-> [E]
         * [S] -*-> SRC -o-> [E]
         * [S] -*-> SRC -> DVC -o-> [E]
         * [S] -*-> SRC -> CTU -> MIX -> DVC -o-> [E]
         *
         * playback     [S] = mem
         *              [E] = SSI
         *
         * capture      [S] = SSI
         *              [E] = mem
         *
         * -*->         Audio DMAC
         * -o->         Audio DMAC peri peri
         */
        mod_start       = (is_play) ? NULL : ssi;
        mod_end         = (is_play) ? ssi  : NULL;

        idx = 0;
        mod[idx++] = mod_start;
        for (i = 1; i < nr; i++) {
                if (src) {
                        mod[idx++] = src;
                        src = NULL;
                } else if (ctu) {
                        mod[idx++] = ctu;
                        ctu = NULL;
                } else if (mix) {
                        mod[idx++] = mix;
                        mix = NULL;
                } else if (dvc) {
                        mod[idx++] = dvc;
                        dvc = NULL;
                }
        }
        mod[idx] = mod_end;

        /*
         *              | SSI | SRC |
         * -------------+-----+-----+
         *  is_play     |  o  |  *  |
         * !is_play     |  *  |  o  |
         */
        if ((this == ssi) == (is_play)) {
                *mod_from       = mod[idx - 1];
                *mod_to         = mod[idx];
        } else {
                *mod_from       = mod[0];
                *mod_to         = mod[1];
        }

        dev_dbg(dev, "module connection (this is %s[%d])\n",
                rsnd_mod_name(this), rsnd_mod_id(this));
        for (i = 0; i <= idx; i++) {
                dev_dbg(dev, "  %s[%d]%s\n",
                        rsnd_mod_name(mod[i] ? mod[i] : &mem),
                        rsnd_mod_id  (mod[i] ? mod[i] : &mem),
                        (mod[i] == *mod_from) ? " from" :
                        (mod[i] == *mod_to)   ? " to" : "");
        }
}

static int rsnd_dma_alloc(struct rsnd_dai_stream *io, struct rsnd_mod *mod,
                          struct rsnd_mod **dma_mod)
{
        struct rsnd_mod *mod_from = NULL;
        struct rsnd_mod *mod_to = NULL;
        struct rsnd_priv *priv = rsnd_io_to_priv(io);
        struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
        struct device *dev = rsnd_priv_to_dev(priv);
        struct rsnd_dma *dma;
        struct rsnd_mod_ops *ops;
        enum rsnd_mod_type type;
        int (*attach)(struct rsnd_dai_stream *io, struct rsnd_dma *dma,
                      struct rsnd_mod *mod_from, struct rsnd_mod *mod_to);
        int is_play = rsnd_io_is_play(io);
        int ret, dma_id;

        /*
         * DMA failed. try to PIO mode
         * see
         *      rsnd_ssi_fallback()
         *      rsnd_rdai_continuance_probe()
         */
        if (!dmac)
                return -EAGAIN;

        rsnd_dma_of_path(mod, io, is_play, &mod_from, &mod_to);

        /* for Gen2 */
        if (mod_from && mod_to) {
                ops     = &rsnd_dmapp_ops;
                attach  = rsnd_dmapp_attach;
                dma_id  = dmac->dmapp_num;
                type    = RSND_MOD_AUDMAPP;
        } else {
                ops     = &rsnd_dmaen_ops;
                attach  = rsnd_dmaen_attach;
                dma_id  = dmac->dmaen_num;
                type    = RSND_MOD_AUDMA;
        }

        /* for Gen1, overwrite */
        if (rsnd_is_gen1(priv)) {
                ops     = &rsnd_dmaen_ops;
                attach  = rsnd_dmaen_attach;
                dma_id  = dmac->dmaen_num;
                type    = RSND_MOD_AUDMA;
        }

        dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
        if (!dma)
                return -ENOMEM;

        *dma_mod = rsnd_mod_get(dma);

        ret = rsnd_mod_init(priv, *dma_mod, ops, NULL,
                            rsnd_mod_get_status, type, dma_id);
        if (ret < 0)
                return ret;

        dev_dbg(dev, "%s[%d] %s[%d] -> %s[%d]\n",
                rsnd_mod_name(*dma_mod), rsnd_mod_id(*dma_mod),
                rsnd_mod_name(mod_from ? mod_from : &mem),
                rsnd_mod_id  (mod_from ? mod_from : &mem),
                rsnd_mod_name(mod_to   ? mod_to   : &mem),
                rsnd_mod_id  (mod_to   ? mod_to   : &mem));

        ret = attach(io, dma, mod_from, mod_to);
        if (ret < 0)
                return ret;

        dma->src_addr = rsnd_dma_addr(io, mod_from, is_play, 1);
        dma->dst_addr = rsnd_dma_addr(io, mod_to,   is_play, 0);
        dma->mod_from = mod_from;
        dma->mod_to   = mod_to;

        return 0;
}

int rsnd_dma_attach(struct rsnd_dai_stream *io, struct rsnd_mod *mod,
                    struct rsnd_mod **dma_mod)
{
        if (!(*dma_mod)) {
                int ret = rsnd_dma_alloc(io, mod, dma_mod);

                if (ret < 0)
                        return ret;
        }

        return rsnd_dai_connect(*dma_mod, io, (*dma_mod)->type);
}

int rsnd_dma_probe(struct rsnd_priv *priv)
{
        struct platform_device *pdev = rsnd_priv_to_pdev(priv);
        struct device *dev = rsnd_priv_to_dev(priv);
        struct rsnd_dma_ctrl *dmac;
        struct resource *res;

        /*
         * for Gen1
         */
        if (rsnd_is_gen1(priv))
                return 0;

        /*
         * for Gen2
         */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "audmapp");
        dmac = devm_kzalloc(dev, sizeof(*dmac), GFP_KERNEL);
        if (!dmac || !res) {
                dev_err(dev, "dma allocate failed\n");
                return 0; /* it will be PIO mode */
        }

        dmac->dmapp_num = 0;
        dmac->base = devm_ioremap_resource(dev, res);
        if (IS_ERR(dmac->base))
                return PTR_ERR(dmac->base);

        priv->dma = dmac;

        /* dummy mem mod for debug */
        return rsnd_mod_init(NULL, &mem, &mem_ops, NULL, NULL, 0, 0);
}