ASoC: Intel: Add Intel Baytrail SST DSP IPC support

Add support for Baytrail SST DSP IPC. This provides mechanism to communicate
with the DSP firmware.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Liam Girdwood <liam.r.girdwood@intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

2 files changed, 935 insertions, 0 deletions

diff --git a/sound/soc/intel/sst-baytrail-ipc.c b/sound/soc/intel/sst-baytrail-ipc.c
new file mode 100644
index 000000000000..8c91a68b90bc
--- /dev/null
+++ b/sound/soc/intel/sst-baytrail-ipc.c
@@ -0,0 +1,866 @@
+/*
+ * Intel Baytrail SST IPC Support
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * 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/types.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/platform_device.h>
+#include <linux/kthread.h>
+#include <linux/firmware.h>
+#include <asm/div64.h>
+
+#include "sst-baytrail-ipc.h"
+#include "sst-dsp.h"
+#include "sst-dsp-priv.h"
+
+/* IPC message timeout */
+#define IPC_TIMEOUT_MSECS       300
+#define IPC_BOOT_MSECS          200
+
+#define IPC_EMPTY_LIST_SIZE     8
+
+/* IPC header bits */
+#define IPC_HEADER_MSG_ID_MASK  0xff
+#define IPC_HEADER_MSG_ID(x)    ((x) & IPC_HEADER_MSG_ID_MASK)
+#define IPC_HEADER_STR_ID_SHIFT 8
+#define IPC_HEADER_STR_ID_MASK  0x1f
+#define IPC_HEADER_STR_ID(x)    (((x) & 0x1f) << IPC_HEADER_STR_ID_SHIFT)
+#define IPC_HEADER_LARGE_SHIFT  13
+#define IPC_HEADER_LARGE(x)     (((x) & 0x1) << IPC_HEADER_LARGE_SHIFT)
+#define IPC_HEADER_DATA_SHIFT   16
+#define IPC_HEADER_DATA_MASK    0x3fff
+#define IPC_HEADER_DATA(x)      (((x) & 0x3fff) << IPC_HEADER_DATA_SHIFT)
+
+/* mask for differentiating between notification and reply message */
+#define IPC_NOTIFICATION        (0x1 << 7)
+
+/* I2L Stream config/control msgs */
+#define IPC_IA_ALLOC_STREAM     0x20
+#define IPC_IA_FREE_STREAM      0x21
+#define IPC_IA_PAUSE_STREAM     0x24
+#define IPC_IA_RESUME_STREAM    0x25
+#define IPC_IA_DROP_STREAM      0x26
+#define IPC_IA_START_STREAM     0x30
+
+/* notification messages */
+#define IPC_IA_FW_INIT_CMPLT    0x81
+#define IPC_SST_PERIOD_ELAPSED  0x97
+
+/* IPC messages between host and ADSP */
+struct sst_byt_address_info {
+        u32 addr;
+        u32 size;
+} __packed;
+
+struct sst_byt_str_type {
+        u8 codec_type;
+        u8 str_type;
+        u8 operation;
+        u8 protected_str;
+        u8 time_slots;
+        u8 reserved;
+        u16 result;
+} __packed;
+
+struct sst_byt_pcm_params {
+        u8 num_chan;
+        u8 pcm_wd_sz;
+        u8 use_offload_path;
+        u8 reserved;
+        u32 sfreq;
+        u8 channel_map[8];
+} __packed;
+
+struct sst_byt_frames_info {
+        u16 num_entries;
+        u16 rsrvd;
+        u32 frag_size;
+        struct sst_byt_address_info ring_buf_info[8];
+} __packed;
+
+struct sst_byt_alloc_params {
+        struct sst_byt_str_type str_type;
+        struct sst_byt_pcm_params pcm_params;
+        struct sst_byt_frames_info frame_info;
+} __packed;
+
+struct sst_byt_alloc_response {
+        struct sst_byt_str_type str_type;
+        u8 reserved[88];
+} __packed;
+
+struct sst_byt_start_stream_params {
+        u32 byte_offset;
+} __packed;
+
+struct sst_byt_tstamp {
+        u64 ring_buffer_counter;
+        u64 hardware_counter;
+        u64 frames_decoded;
+        u64 bytes_decoded;
+        u64 bytes_copied;
+        u32 sampling_frequency;
+        u32 channel_peak[8];
+} __packed;
+
+/* driver internal IPC message structure */
+struct ipc_message {
+        struct list_head list;
+        u64 header;
+
+        /* direction wrt host CPU */
+        char tx_data[SST_BYT_IPC_MAX_PAYLOAD_SIZE];
+        size_t tx_size;
+        char rx_data[SST_BYT_IPC_MAX_PAYLOAD_SIZE];
+        size_t rx_size;
+
+        wait_queue_head_t waitq;
+        bool complete;
+        bool wait;
+        int errno;
+};
+
+struct sst_byt_stream;
+struct sst_byt;
+
+/* stream infomation */
+struct sst_byt_stream {
+        struct list_head node;
+
+        /* configuration */
+        struct sst_byt_alloc_params request;
+        struct sst_byt_alloc_response reply;
+
+        /* runtime info */
+        struct sst_byt *byt;
+        int str_id;
+        bool commited;
+        bool running;
+
+        /* driver callback */
+        u32 (*notify_position)(struct sst_byt_stream *stream, void *data);
+        void *pdata;
+};
+
+/* SST Baytrail IPC data */
+struct sst_byt {
+        struct device *dev;
+        struct sst_dsp *dsp;
+
+        /* stream */
+        struct list_head stream_list;
+
+        /* boot */
+        wait_queue_head_t boot_wait;
+        bool boot_complete;
+
+        /* IPC messaging */
+        struct list_head tx_list;
+        struct list_head rx_list;
+        struct list_head empty_list;
+        wait_queue_head_t wait_txq;
+        struct task_struct *tx_thread;
+        struct kthread_worker kworker;
+        struct kthread_work kwork;
+        struct ipc_message *msg;
+};
+
+static inline u64 sst_byt_header(int msg_id, int data, bool large, int str_id)
+{
+        u64 header;
+
+        header = IPC_HEADER_MSG_ID(msg_id) |
+                 IPC_HEADER_STR_ID(str_id) |
+                 IPC_HEADER_LARGE(large) |
+                 IPC_HEADER_DATA(data) |
+                 SST_BYT_IPCX_BUSY;
+
+        return header;
+}
+
+static inline u16 sst_byt_header_msg_id(u64 header)
+{
+        return header & IPC_HEADER_MSG_ID_MASK;
+}
+
+static inline u8 sst_byt_header_str_id(u64 header)
+{
+        return (header >> IPC_HEADER_STR_ID_SHIFT) & IPC_HEADER_STR_ID_MASK;
+}
+
+static inline u16 sst_byt_header_data(u64 header)
+{
+        return (header >> IPC_HEADER_DATA_SHIFT) & IPC_HEADER_DATA_MASK;
+}
+
+static struct sst_byt_stream *sst_byt_get_stream(struct sst_byt *byt,
+                                                 int stream_id)
+{
+        struct sst_byt_stream *stream;
+
+        list_for_each_entry(stream, &byt->stream_list, node) {
+                if (stream->str_id == stream_id)
+                        return stream;
+        }
+
+        return NULL;
+}
+
+static void sst_byt_ipc_shim_dbg(struct sst_byt *byt, const char *text)
+{
+        struct sst_dsp *sst = byt->dsp;
+        u64 isr, ipcd, imrx, ipcx;
+
+        ipcx = sst_dsp_shim_read64_unlocked(sst, SST_IPCX);
+        isr = sst_dsp_shim_read64_unlocked(sst, SST_ISRX);
+        ipcd = sst_dsp_shim_read64_unlocked(sst, SST_IPCD);
+        imrx = sst_dsp_shim_read64_unlocked(sst, SST_IMRX);
+
+        dev_err(byt->dev,
+                "ipc: --%s-- ipcx 0x%llx isr 0x%llx ipcd 0x%llx imrx 0x%llx\n",
+                text, ipcx, isr, ipcd, imrx);
+}
+
+/* locks held by caller */
+static struct ipc_message *sst_byt_msg_get_empty(struct sst_byt *byt)
+{
+        struct ipc_message *msg = NULL;
+
+        if (!list_empty(&byt->empty_list)) {
+                msg = list_first_entry(&byt->empty_list,
+                                       struct ipc_message, list);
+                list_del(&msg->list);
+        }
+
+        return msg;
+}
+
+static void sst_byt_ipc_tx_msgs(struct kthread_work *work)
+{
+        struct sst_byt *byt =
+                container_of(work, struct sst_byt, kwork);
+        struct ipc_message *msg;
+        u64 ipcx;
+        unsigned long flags;
+
+        spin_lock_irqsave(&byt->dsp->spinlock, flags);
+        if (list_empty(&byt->tx_list)) {
+                spin_unlock_irqrestore(&byt->dsp->spinlock, flags);
+                return;
+        }
+
+        /* if the DSP is busy we will TX messages after IRQ */
+        ipcx = sst_dsp_shim_read64_unlocked(byt->dsp, SST_IPCX);
+        if (ipcx & SST_BYT_IPCX_BUSY) {
+                spin_unlock_irqrestore(&byt->dsp->spinlock, flags);
+                return;
+        }
+
+        msg = list_first_entry(&byt->tx_list, struct ipc_message, list);
+
+        list_move(&msg->list, &byt->rx_list);
+
+        /* send the message */
+        if (msg->header & IPC_HEADER_LARGE(true))
+                sst_dsp_outbox_write(byt->dsp, msg->tx_data, msg->tx_size);
+        sst_dsp_shim_write64_unlocked(byt->dsp, SST_IPCX, msg->header);
+
+        spin_unlock_irqrestore(&byt->dsp->spinlock, flags);
+}
+
+static inline void sst_byt_tx_msg_reply_complete(struct sst_byt *byt,
+                                                 struct ipc_message *msg)
+{
+        msg->complete = true;
+
+        if (!msg->wait)
+                list_add_tail(&msg->list, &byt->empty_list);
+        else
+                wake_up(&msg->waitq);
+}
+
+static int sst_byt_tx_wait_done(struct sst_byt *byt, struct ipc_message *msg,
+                                void *rx_data)
+{
+        unsigned long flags;
+        int ret;
+
+        /* wait for DSP completion */
+        ret = wait_event_timeout(msg->waitq, msg->complete,
+                                 msecs_to_jiffies(IPC_TIMEOUT_MSECS));
+
+        spin_lock_irqsave(&byt->dsp->spinlock, flags);
+        if (ret == 0) {
+                list_del(&msg->list);
+                sst_byt_ipc_shim_dbg(byt, "message timeout");
+
+                ret = -ETIMEDOUT;
+        } else {
+
+                /* copy the data returned from DSP */
+                if (msg->rx_size)
+                        memcpy(rx_data, msg->rx_data, msg->rx_size);
+                ret = msg->errno;
+        }
+
+        list_add_tail(&msg->list, &byt->empty_list);
+        spin_unlock_irqrestore(&byt->dsp->spinlock, flags);
+        return ret;
+}
+
+static int sst_byt_ipc_tx_message(struct sst_byt *byt, u64 header,
+                                  void *tx_data, size_t tx_bytes,
+                                  void *rx_data, size_t rx_bytes, int wait)
+{
+        unsigned long flags;
+        struct ipc_message *msg;
+
+        spin_lock_irqsave(&byt->dsp->spinlock, flags);
+
+        msg = sst_byt_msg_get_empty(byt);
+        if (msg == NULL) {
+                spin_unlock_irqrestore(&byt->dsp->spinlock, flags);
+                return -EBUSY;
+        }
+
+        msg->header = header;
+        msg->tx_size = tx_bytes;
+        msg->rx_size = rx_bytes;
+        msg->wait = wait;
+        msg->errno = 0;
+        msg->complete = false;
+
+        if (tx_bytes) {
+                /* msg content = lower 32-bit of the header + data */
+                *(u32 *)msg->tx_data = (u32)(header & (u32)-1);
+                memcpy(msg->tx_data + sizeof(u32), tx_data, tx_bytes);
+                msg->tx_size += sizeof(u32);
+        }
+
+        list_add_tail(&msg->list, &byt->tx_list);
+        spin_unlock_irqrestore(&byt->dsp->spinlock, flags);
+
+        queue_kthread_work(&byt->kworker, &byt->kwork);
+
+        if (wait)
+                return sst_byt_tx_wait_done(byt, msg, rx_data);
+        else
+                return 0;
+}
+
+static inline int sst_byt_ipc_tx_msg_wait(struct sst_byt *byt, u64 header,
+                                          void *tx_data, size_t tx_bytes,
+                                          void *rx_data, size_t rx_bytes)
+{
+        return sst_byt_ipc_tx_message(byt, header, tx_data, tx_bytes,
+                                      rx_data, rx_bytes, 1);
+}
+
+static inline int sst_byt_ipc_tx_msg_nowait(struct sst_byt *byt, u64 header,
+                                                void *tx_data, size_t tx_bytes)
+{
+        return sst_byt_ipc_tx_message(byt, header, tx_data, tx_bytes,
+                                      NULL, 0, 0);
+}
+
+static struct ipc_message *sst_byt_reply_find_msg(struct sst_byt *byt,
+                                                  u64 header)
+{
+        struct ipc_message *msg = NULL, *_msg;
+        u64 mask;
+
+        /* match reply to message sent based on msg and stream IDs */
+        mask = IPC_HEADER_MSG_ID_MASK |
+               IPC_HEADER_STR_ID_MASK << IPC_HEADER_STR_ID_SHIFT;
+        header &= mask;
+
+        if (list_empty(&byt->rx_list)) {
+                dev_err(byt->dev,
+                        "ipc: rx list is empty but received 0x%llx\n", header);
+                goto out;
+        }
+
+        list_for_each_entry(_msg, &byt->rx_list, list) {
+                if ((_msg->header & mask) == header) {
+                        msg = _msg;
+                        break;
+                }
+        }
+
+out:
+        return msg;
+}
+
+static void sst_byt_stream_update(struct sst_byt *byt, struct ipc_message *msg)
+{
+        struct sst_byt_stream *stream;
+        u64 header = msg->header;
+        u8 stream_id = sst_byt_header_str_id(header);
+        u8 stream_msg = sst_byt_header_msg_id(header);
+
+        stream = sst_byt_get_stream(byt, stream_id);
+        if (stream == NULL)
+                return;
+
+        switch (stream_msg) {
+        case IPC_IA_DROP_STREAM:
+        case IPC_IA_PAUSE_STREAM:
+        case IPC_IA_FREE_STREAM:
+                stream->running = false;
+                break;
+        case IPC_IA_START_STREAM:
+        case IPC_IA_RESUME_STREAM:
+                stream->running = true;
+                break;
+        }
+}
+
+static int sst_byt_process_reply(struct sst_byt *byt, u64 header)
+{
+        struct ipc_message *msg;
+
+        msg = sst_byt_reply_find_msg(byt, header);
+        if (msg == NULL)
+                return 1;
+
+        if (header & IPC_HEADER_LARGE(true)) {
+                msg->rx_size = sst_byt_header_data(header);
+                sst_dsp_inbox_read(byt->dsp, msg->rx_data, msg->rx_size);
+        }
+
+        /* update any stream states */
+        sst_byt_stream_update(byt, msg);
+
+        list_del(&msg->list);
+        /* wake up */
+        sst_byt_tx_msg_reply_complete(byt, msg);
+
+        return 1;
+}
+
+static void sst_byt_fw_ready(struct sst_byt *byt, u64 header)
+{
+        dev_dbg(byt->dev, "ipc: DSP is ready 0x%llX\n", header);
+
+        byt->boot_complete = true;
+        wake_up(&byt->boot_wait);
+}
+
+static int sst_byt_process_notification(struct sst_byt *byt,
+                                        unsigned long *flags)
+{
+        struct sst_dsp *sst = byt->dsp;
+        struct sst_byt_stream *stream;
+        u64 header;
+        u8 msg_id, stream_id;
+        int handled = 1;
+
+        header = sst_dsp_shim_read64_unlocked(sst, SST_IPCD);
+        msg_id = sst_byt_header_msg_id(header);
+
+        switch (msg_id) {
+        case IPC_SST_PERIOD_ELAPSED:
+                stream_id = sst_byt_header_str_id(header);
+                stream = sst_byt_get_stream(byt, stream_id);
+                if (stream && stream->running && stream->notify_position) {
+                        spin_unlock_irqrestore(&sst->spinlock, *flags);
+                        stream->notify_position(stream, stream->pdata);
+                        spin_lock_irqsave(&sst->spinlock, *flags);
+                }
+                break;
+        case IPC_IA_FW_INIT_CMPLT:
+                sst_byt_fw_ready(byt, header);
+                break;
+        }
+
+        return handled;
+}
+
+static irqreturn_t sst_byt_irq_thread(int irq, void *context)
+{
+        struct sst_dsp *sst = (struct sst_dsp *) context;
+        struct sst_byt *byt = sst_dsp_get_thread_context(sst);
+        u64 header;
+        unsigned long flags;
+
+        spin_lock_irqsave(&sst->spinlock, flags);
+
+        header = sst_dsp_shim_read64_unlocked(sst, SST_IPCD);
+        if (header & SST_BYT_IPCD_BUSY) {
+                if (header & IPC_NOTIFICATION) {
+                        /* message from ADSP */
+                        sst_byt_process_notification(byt, &flags);
+                } else {
+                        /* reply from ADSP */
+                        sst_byt_process_reply(byt, header);
+                }
+                /*
+                 * clear IPCD BUSY bit and set DONE bit. Tell DSP we have
+                 * processed the message and can accept new. Clear data part
+                 * of the header
+                 */
+                sst_dsp_shim_update_bits64_unlocked(sst, SST_IPCD,
+                        SST_BYT_IPCD_DONE | SST_BYT_IPCD_BUSY |
+                        IPC_HEADER_DATA(IPC_HEADER_DATA_MASK),
+                        SST_BYT_IPCD_DONE);
+                /* unmask message request interrupts */
+                sst_dsp_shim_update_bits64_unlocked(sst, SST_IMRX,
+                        SST_BYT_IMRX_REQUEST, 0);
+        }
+
+        spin_unlock_irqrestore(&sst->spinlock, flags);
+
+        /* continue to send any remaining messages... */
+        queue_kthread_work(&byt->kworker, &byt->kwork);
+
+        return IRQ_HANDLED;
+}
+
+/* stream API */
+struct sst_byt_stream *sst_byt_stream_new(struct sst_byt *byt, int id,
+        u32 (*notify_position)(struct sst_byt_stream *stream, void *data),
+        void *data)
+{
+        struct sst_byt_stream *stream;
+
+        stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+        if (stream == NULL)
+                return NULL;
+
+        list_add(&stream->node, &byt->stream_list);
+        stream->notify_position = notify_position;
+        stream->pdata = data;
+        stream->byt = byt;
+        stream->str_id = id;
+
+        return stream;
+}
+
+int sst_byt_stream_set_bits(struct sst_byt *byt, struct sst_byt_stream *stream,
+                            int bits)
+{
+        stream->request.pcm_params.pcm_wd_sz = bits;
+        return 0;
+}
+
+int sst_byt_stream_set_channels(struct sst_byt *byt,
+                                struct sst_byt_stream *stream, u8 channels)
+{
+        stream->request.pcm_params.num_chan = channels;
+        return 0;
+}
+
+int sst_byt_stream_set_rate(struct sst_byt *byt, struct sst_byt_stream *stream,
+                            unsigned int rate)
+{
+        stream->request.pcm_params.sfreq = rate;
+        return 0;
+}
+
+/* stream sonfiguration */
+int sst_byt_stream_type(struct sst_byt *byt, struct sst_byt_stream *stream,
+                        int codec_type, int stream_type, int operation)
+{
+        stream->request.str_type.codec_type = codec_type;
+        stream->request.str_type.str_type = stream_type;
+        stream->request.str_type.operation = operation;
+        stream->request.str_type.time_slots = 0xc;
+
+        return 0;
+}
+
+int sst_byt_stream_buffer(struct sst_byt *byt, struct sst_byt_stream *stream,
+                          uint32_t buffer_addr, uint32_t buffer_size)
+{
+        stream->request.frame_info.num_entries = 1;
+        stream->request.frame_info.ring_buf_info[0].addr = buffer_addr;
+        stream->request.frame_info.ring_buf_info[0].size = buffer_size;
+        /* calculate bytes per 4 ms fragment */
+        stream->request.frame_info.frag_size =
+                stream->request.pcm_params.sfreq *
+                stream->request.pcm_params.num_chan *
+                stream->request.pcm_params.pcm_wd_sz / 8 *
+                4 / 1000;
+        return 0;
+}
+
+int sst_byt_stream_commit(struct sst_byt *byt, struct sst_byt_stream *stream)
+{
+        struct sst_byt_alloc_params *str_req = &stream->request;
+        struct sst_byt_alloc_response *reply = &stream->reply;
+        u64 header;
+        int ret;
+
+        header = sst_byt_header(IPC_IA_ALLOC_STREAM,
+                                sizeof(*str_req) + sizeof(u32),
+                                true, stream->str_id);
+        ret = sst_byt_ipc_tx_msg_wait(byt, header, str_req, sizeof(*str_req),
+                                      reply, sizeof(*reply));
+        if (ret < 0) {
+                dev_err(byt->dev, "ipc: error stream commit failed\n");
+                return ret;
+        }
+
+        stream->commited = true;
+
+        return 0;
+}
+
+int sst_byt_stream_free(struct sst_byt *byt, struct sst_byt_stream *stream)
+{
+        u64 header;
+        int ret = 0;
+
+        if (!stream->commited)
+                goto out;
+
+        header = sst_byt_header(IPC_IA_FREE_STREAM, 0, false, stream->str_id);
+        ret = sst_byt_ipc_tx_msg_wait(byt, header, NULL, 0, NULL, 0);
+        if (ret < 0) {
+                dev_err(byt->dev, "ipc: free stream %d failed\n",
+                        stream->str_id);
+                return -EAGAIN;
+        }
+
+        stream->commited = false;
+out:
+        list_del(&stream->node);
+        kfree(stream);
+
+        return ret;
+}
+
+static int sst_byt_stream_operations(struct sst_byt *byt, int type,
+                                     int stream_id, int wait)
+{
+        struct sst_byt_start_stream_params start_stream;
+        u64 header;
+        void *tx_msg = NULL;
+        size_t size = 0;
+
+        if (type != IPC_IA_START_STREAM) {
+                header = sst_byt_header(type, 0, false, stream_id);
+        } else {
+                start_stream.byte_offset = 0;
+                header = sst_byt_header(IPC_IA_START_STREAM,
+                                        sizeof(start_stream) + sizeof(u32),
+                                        true, stream_id);
+                tx_msg = &start_stream;
+                size = sizeof(start_stream);
+        }
+
+        if (wait)
+                return sst_byt_ipc_tx_msg_wait(byt, header,
+                                               tx_msg, size, NULL, 0);
+        else
+                return sst_byt_ipc_tx_msg_nowait(byt, header, tx_msg, size);
+}
+
+/* stream ALSA trigger operations */
+int sst_byt_stream_start(struct sst_byt *byt, struct sst_byt_stream *stream)
+{
+        int ret;
+
+        ret = sst_byt_stream_operations(byt, IPC_IA_START_STREAM,
+                                        stream->str_id, 0);
+        if (ret < 0)
+                dev_err(byt->dev, "ipc: error failed to start stream %d\n",
+                        stream->str_id);
+
+        return ret;
+}
+
+int sst_byt_stream_stop(struct sst_byt *byt, struct sst_byt_stream *stream)
+{
+        int ret;
+
+        /* don't stop streams that are not commited */
+        if (!stream->commited)
+                return 0;
+
+        ret = sst_byt_stream_operations(byt, IPC_IA_DROP_STREAM,
+                                        stream->str_id, 0);
+        if (ret < 0)
+                dev_err(byt->dev, "ipc: error failed to stop stream %d\n",
+                        stream->str_id);
+        return ret;
+}
+
+int sst_byt_stream_pause(struct sst_byt *byt, struct sst_byt_stream *stream)
+{
+        int ret;
+
+        ret = sst_byt_stream_operations(byt, IPC_IA_PAUSE_STREAM,
+                                        stream->str_id, 0);
+        if (ret < 0)
+                dev_err(byt->dev, "ipc: error failed to pause stream %d\n",
+                        stream->str_id);
+
+        return ret;
+}
+
+int sst_byt_stream_resume(struct sst_byt *byt, struct sst_byt_stream *stream)
+{
+        int ret;
+
+        ret = sst_byt_stream_operations(byt, IPC_IA_RESUME_STREAM,
+                                        stream->str_id, 0);
+        if (ret < 0)
+                dev_err(byt->dev, "ipc: error failed to resume stream %d\n",
+                        stream->str_id);
+
+        return ret;
+}
+
+int sst_byt_get_dsp_position(struct sst_byt *byt,
+                             struct sst_byt_stream *stream, int buffer_size)
+{
+        struct sst_dsp *sst = byt->dsp;
+        struct sst_byt_tstamp fw_tstamp;
+        u8 str_id = stream->str_id;
+        u32 tstamp_offset;
+
+        tstamp_offset = SST_BYT_TIMESTAMP_OFFSET + str_id * sizeof(fw_tstamp);
+        memcpy_fromio(&fw_tstamp,
+                      sst->addr.lpe + tstamp_offset, sizeof(fw_tstamp));
+
+        return do_div(fw_tstamp.ring_buffer_counter, buffer_size);
+}
+
+static int msg_empty_list_init(struct sst_byt *byt)
+{
+        struct ipc_message *msg;
+        int i;
+
+        byt->msg = kzalloc(sizeof(*msg) * IPC_EMPTY_LIST_SIZE, GFP_KERNEL);
+        if (byt->msg == NULL)
+                return -ENOMEM;
+
+        for (i = 0; i < IPC_EMPTY_LIST_SIZE; i++) {
+                init_waitqueue_head(&byt->msg[i].waitq);
+                list_add(&byt->msg[i].list, &byt->empty_list);
+        }
+
+        return 0;
+}
+
+struct sst_dsp *sst_byt_get_dsp(struct sst_byt *byt)
+{
+        return byt->dsp;
+}
+
+static struct sst_dsp_device byt_dev = {
+        .thread = sst_byt_irq_thread,
+        .ops = &sst_byt_ops,
+};
+
+int sst_byt_dsp_init(struct device *dev, struct sst_pdata *pdata)
+{
+        struct sst_byt *byt;
+        struct sst_fw *byt_sst_fw;
+        int err;
+
+        dev_dbg(dev, "initialising Byt DSP IPC\n");
+
+        byt = devm_kzalloc(dev, sizeof(*byt), GFP_KERNEL);
+        if (byt == NULL)
+                return -ENOMEM;
+
+        byt->dev = dev;
+        INIT_LIST_HEAD(&byt->stream_list);
+        INIT_LIST_HEAD(&byt->tx_list);
+        INIT_LIST_HEAD(&byt->rx_list);
+        INIT_LIST_HEAD(&byt->empty_list);
+        init_waitqueue_head(&byt->boot_wait);
+        init_waitqueue_head(&byt->wait_txq);
+
+        err = msg_empty_list_init(byt);
+        if (err < 0)
+                goto list_err;
+
+        /* start the IPC message thread */
+        init_kthread_worker(&byt->kworker);
+        byt->tx_thread = kthread_run(kthread_worker_fn,
+                                     &byt->kworker,
+                                     dev_name(byt->dev));
+        if (IS_ERR(byt->tx_thread)) {
+                err = PTR_ERR(byt->tx_thread);
+                dev_err(byt->dev, "error failed to create message TX task\n");
+                goto list_err;
+        }
+        init_kthread_work(&byt->kwork, sst_byt_ipc_tx_msgs);
+
+        byt_dev.thread_context = byt;
+
+        /* init SST shim */
+        byt->dsp = sst_dsp_new(dev, &byt_dev, pdata);
+        if (byt->dsp == NULL) {
+                err = -ENODEV;
+                goto list_err;
+        }
+
+        /* keep the DSP in reset state for base FW loading */
+        sst_dsp_reset(byt->dsp);
+
+        byt_sst_fw = sst_fw_new(byt->dsp, pdata->fw, byt);
+        if (byt_sst_fw  == NULL) {
+                err = -ENODEV;
+                dev_err(dev, "error: failed to load firmware\n");
+                goto fw_err;
+        }
+
+        /* wait for DSP boot completion */
+        sst_dsp_boot(byt->dsp);
+        err = wait_event_timeout(byt->boot_wait, byt->boot_complete,
+                                 msecs_to_jiffies(IPC_BOOT_MSECS));
+        if (err == 0) {
+                err = -EIO;
+                dev_err(byt->dev, "ipc: error DSP boot timeout\n");
+                goto boot_err;
+        }
+
+        pdata->dsp = byt;
+
+        return 0;
+
+boot_err:
+        sst_dsp_reset(byt->dsp);
+        sst_fw_free(byt_sst_fw);
+fw_err:
+        sst_dsp_free(byt->dsp);
+        kfree(byt->msg);
+list_err:
+        kfree(byt);
+        return err;
+}
+EXPORT_SYMBOL_GPL(sst_byt_dsp_init);
+
+void sst_byt_dsp_free(struct device *dev, struct sst_pdata *pdata)
+{
+        struct sst_byt *byt = pdata->dsp;
+
+        sst_dsp_reset(byt->dsp);
+        sst_fw_free_all(byt->dsp);
+        sst_dsp_free(byt->dsp);
+        kfree(byt->msg);
+}
+EXPORT_SYMBOL_GPL(sst_byt_dsp_free);
diff --git a/sound/soc/intel/sst-baytrail-ipc.h b/sound/soc/intel/sst-baytrail-ipc.h
new file mode 100644
index 000000000000..f172b6440fa9
--- /dev/null
+++ b/sound/soc/intel/sst-baytrail-ipc.h
@@ -0,0 +1,69 @@
+/*
+ * Intel Baytrail SST IPC Support
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * 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.
+ */
+
+#ifndef __SST_BYT_IPC_H
+#define __SST_BYT_IPC_H
+
+#include <linux/types.h>
+
+struct sst_byt;
+struct sst_byt_stream;
+struct sst_pdata;
+extern struct sst_ops sst_byt_ops;
+
+
+#define SST_BYT_MAILBOX_OFFSET          0x144000
+#define SST_BYT_TIMESTAMP_OFFSET        (SST_BYT_MAILBOX_OFFSET + 0x800)
+
+/**
+ * Upfront defined maximum message size that is
+ * expected by the in/out communication pipes in FW.
+ */
+#define SST_BYT_IPC_MAX_PAYLOAD_SIZE    200
+
+/* stream API */
+struct sst_byt_stream *sst_byt_stream_new(struct sst_byt *byt, int id,
+        uint32_t (*get_write_position)(struct sst_byt_stream *stream,
+                                       void *data),
+        void *data);
+
+/* stream configuration */
+int sst_byt_stream_set_bits(struct sst_byt *byt, struct sst_byt_stream *stream,
+                            int bits);
+int sst_byt_stream_set_channels(struct sst_byt *byt,
+                                struct sst_byt_stream *stream, u8 channels);
+int sst_byt_stream_set_rate(struct sst_byt *byt, struct sst_byt_stream *stream,
+                            unsigned int rate);
+int sst_byt_stream_type(struct sst_byt *byt, struct sst_byt_stream *stream,
+                        int codec_type, int stream_type, int operation);
+int sst_byt_stream_buffer(struct sst_byt *byt, struct sst_byt_stream *stream,
+                          uint32_t buffer_addr, uint32_t buffer_size);
+int sst_byt_stream_commit(struct sst_byt *byt, struct sst_byt_stream *stream);
+int sst_byt_stream_free(struct sst_byt *byt, struct sst_byt_stream *stream);
+
+/* stream ALSA trigger operations */
+int sst_byt_stream_start(struct sst_byt *byt, struct sst_byt_stream *stream);
+int sst_byt_stream_stop(struct sst_byt *byt, struct sst_byt_stream *stream);
+int sst_byt_stream_pause(struct sst_byt *byt, struct sst_byt_stream *stream);
+int sst_byt_stream_resume(struct sst_byt *byt, struct sst_byt_stream *stream);
+
+int sst_byt_get_dsp_position(struct sst_byt *byt,
+                             struct sst_byt_stream *stream, int buffer_size);
+
+/* init */
+int sst_byt_dsp_init(struct device *dev, struct sst_pdata *pdata);
+void sst_byt_dsp_free(struct device *dev, struct sst_pdata *pdata);
+struct sst_dsp *sst_byt_get_dsp(struct sst_byt *byt);
+
+#endif