// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018, Linaro Limited

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/slimbus.h>
#include <uapi/sound/asound.h>
#include "slimbus.h"

/**
 * struct segdist_code - Segment Distributions code from
 *      Table 20 of SLIMbus Specs Version 2.0
 *
 * @ratem: Channel Rate Multipler(Segments per Superframe)
 * @seg_interval: Number of slots between the first Slot of Segment
 *              and the first slot of the next  consecutive Segment.
 * @segdist_code: Segment Distribution Code SD[11:0]
 * @seg_offset_mask: Segment offset mask in SD[11:0]
 */
struct segdist_code {
        int ratem;
        int seg_interval;
        int segdist_code;
        u32 seg_offset_mask;

};

/* segdist_codes - List of all possible Segment Distribution codes. */
static const struct segdist_code segdist_codes[] = {
        {1,     1536,   0x200,   0xdff},
        {2,     768,    0x100,   0xcff},
        {4,     384,    0x080,   0xc7f},
        {8,     192,    0x040,   0xc3f},
        {16,    96,     0x020,   0xc1f},
        {32,    48,     0x010,   0xc0f},
        {64,    24,     0x008,   0xc07},
        {128,   12,     0x004,   0xc03},
        {256,   6,      0x002,   0xc01},
        {512,   3,      0x001,   0xc00},
        {3,     512,    0xe00,   0x1ff},
        {6,     256,    0xd00,   0x0ff},
        {12,    128,    0xc80,   0x07f},
        {24,    64,     0xc40,   0x03f},
        {48,    32,     0xc20,   0x01f},
        {96,    16,     0xc10,   0x00f},
        {192,   8,      0xc08,   0x007},
        {364,   4,      0xc04,   0x003},
        {768,   2,      0xc02,   0x001},
};

/*
 * Presence Rate table for all Natural Frequencies
 * The Presence rate of a constant bitrate stream is mean flow rate of the
 * stream expressed in occupied Segments of that Data Channel per second.
 * Table 66 from SLIMbus 2.0 Specs
 *
 * Index of the table corresponds to Presence rate code for the respective rate
 * in the table.
 */
static const int slim_presence_rate_table[] = {
        0, /* Not Indicated */
        12000,
        24000,
        48000,
        96000,
        192000,
        384000,
        768000,
        0, /* Reserved */
        11025,
        22050,
        44100,
        88200,
        176400,
        352800,
        705600,
        4000,
        8000,
        16000,
        32000,
        64000,
        128000,
        256000,
        512000,
};

/**
 * slim_stream_allocate() - Allocate a new SLIMbus Stream
 * @dev:Slim device to be associated with
 * @name: name of the stream
 *
 * This is very first call for SLIMbus streaming, this API will allocate
 * a new SLIMbus stream and return a valid stream runtime pointer for client
 * to use it in subsequent stream apis. state of stream is set to ALLOCATED
 *
 * Return: valid pointer on success and error code on failure.
 * From ASoC DPCM framework, this state is linked to startup() operation.
 */
struct slim_stream_runtime *slim_stream_allocate(struct slim_device *dev,
                                                 const char *name)
{
        struct slim_stream_runtime *rt;

        rt = kzalloc_obj(*rt);
        if (!rt)
                return ERR_PTR(-ENOMEM);

        rt->name = kasprintf(GFP_KERNEL, "slim-%s", name);
        if (!rt->name) {
                kfree(rt);
                return ERR_PTR(-ENOMEM);
        }

        rt->dev = dev;
        spin_lock(&dev->stream_list_lock);
        list_add_tail(&rt->node, &dev->stream_list);
        spin_unlock(&dev->stream_list_lock);

        return rt;
}
EXPORT_SYMBOL_GPL(slim_stream_allocate);

static int slim_connect_port_channel(struct slim_stream_runtime *stream,
                                     struct slim_port *port)
{
        struct slim_device *sdev = stream->dev;
        u8 wbuf[2];
        struct slim_val_inf msg = {0, 2, NULL, wbuf, NULL};
        u8 mc = SLIM_MSG_MC_CONNECT_SOURCE;
        DEFINE_SLIM_LDEST_TXN(txn, mc, 6, stream->dev->laddr, &msg);

        if (port->direction == SLIM_PORT_SINK)
                txn.mc = SLIM_MSG_MC_CONNECT_SINK;

        wbuf[0] = port->id;
        wbuf[1] = port->ch.id;
        port->ch.state = SLIM_CH_STATE_ASSOCIATED;
        port->state = SLIM_PORT_UNCONFIGURED;

        return slim_do_transfer(sdev->ctrl, &txn);
}

static int slim_disconnect_port(struct slim_stream_runtime *stream,
                                struct slim_port *port)
{
        struct slim_device *sdev = stream->dev;
        u8 wbuf[1];
        struct slim_val_inf msg = {0, 1, NULL, wbuf, NULL};
        u8 mc = SLIM_MSG_MC_DISCONNECT_PORT;
        DEFINE_SLIM_LDEST_TXN(txn, mc, 5, stream->dev->laddr, &msg);

        wbuf[0] = port->id;
        port->ch.state = SLIM_CH_STATE_DISCONNECTED;
        port->state = SLIM_PORT_DISCONNECTED;

        return slim_do_transfer(sdev->ctrl, &txn);
}

static int slim_deactivate_remove_channel(struct slim_stream_runtime *stream,
                                          struct slim_port *port)
{
        struct slim_device *sdev = stream->dev;
        u8 wbuf[1];
        struct slim_val_inf msg = {0, 1, NULL, wbuf, NULL};
        u8 mc = SLIM_MSG_MC_NEXT_DEACTIVATE_CHANNEL;
        DEFINE_SLIM_LDEST_TXN(txn, mc, 5, stream->dev->laddr, &msg);
        int ret;

        wbuf[0] = port->ch.id;
        ret = slim_do_transfer(sdev->ctrl, &txn);
        if (ret)
                return ret;

        txn.mc = SLIM_MSG_MC_NEXT_REMOVE_CHANNEL;
        port->ch.state = SLIM_CH_STATE_REMOVED;

        return slim_do_transfer(sdev->ctrl, &txn);
}

static int slim_get_prate_code(int rate)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(slim_presence_rate_table); i++) {
                if (rate == slim_presence_rate_table[i])
                        return i;
        }

        return -EINVAL;
}

/**
 * slim_stream_prepare() - Prepare a SLIMbus Stream
 *
 * @rt: instance of slim stream runtime to configure
 * @cfg: new configuration for the stream
 *
 * This API will configure SLIMbus stream with config parameters from cfg.
 * return zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to hw_params() operation.
 */
int slim_stream_prepare(struct slim_stream_runtime *rt,
                        struct slim_stream_config *cfg)
{
        struct slim_controller *ctrl = rt->dev->ctrl;
        struct slim_port *port;
        int num_ports, i, port_id, prrate;

        if (rt->ports) {
                dev_err(&rt->dev->dev, "Stream already Prepared\n");
                return -EINVAL;
        }

        num_ports = hweight32(cfg->port_mask);
        rt->ports = kzalloc_objs(*port, num_ports);
        if (!rt->ports)
                return -ENOMEM;

        rt->num_ports = num_ports;
        rt->rate = cfg->rate;
        rt->bps = cfg->bps;
        rt->direction = cfg->direction;

        prrate = slim_get_prate_code(cfg->rate);
        if (prrate < 0) {
                dev_err(&rt->dev->dev, "Cannot get presence rate for rate %d Hz\n",
                        cfg->rate);
                return prrate;
        }

        if (cfg->rate % ctrl->a_framer->superfreq) {
                /*
                 * data rate not exactly multiple of super frame,
                 * use PUSH/PULL protocol
                 */
                if (cfg->direction == SNDRV_PCM_STREAM_PLAYBACK)
                        rt->prot = SLIM_PROTO_PUSH;
                else
                        rt->prot = SLIM_PROTO_PULL;
        } else {
                rt->prot = SLIM_PROTO_ISO;
        }

        rt->ratem = cfg->rate/ctrl->a_framer->superfreq;

        i = 0;
        for_each_set_bit(port_id, &cfg->port_mask, SLIM_DEVICE_MAX_PORTS) {
                port = &rt->ports[i];
                port->state = SLIM_PORT_DISCONNECTED;
                port->id = port_id;
                port->ch.prrate = prrate;
                port->ch.id = cfg->chs[i];
                port->ch.data_fmt = SLIM_CH_DATA_FMT_NOT_DEFINED;
                port->ch.aux_fmt = SLIM_CH_AUX_FMT_NOT_APPLICABLE;
                port->ch.state = SLIM_CH_STATE_ALLOCATED;

                if (cfg->direction == SNDRV_PCM_STREAM_PLAYBACK)
                        port->direction = SLIM_PORT_SINK;
                else
                        port->direction = SLIM_PORT_SOURCE;

                slim_connect_port_channel(rt, port);
                i++;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(slim_stream_prepare);

static int slim_define_channel_content(struct slim_stream_runtime *stream,
                                       struct slim_port *port)
{
        struct slim_device *sdev = stream->dev;
        u8 wbuf[4];
        struct slim_val_inf msg = {0, 4, NULL, wbuf, NULL};
        u8 mc = SLIM_MSG_MC_NEXT_DEFINE_CONTENT;
        DEFINE_SLIM_LDEST_TXN(txn, mc, 8, stream->dev->laddr, &msg);

        wbuf[0] = port->ch.id;
        wbuf[1] = port->ch.prrate;

        /* Frequency Locked for ISO Protocol */
        if (stream->prot != SLIM_PROTO_ISO)
                wbuf[1] |= SLIM_CHANNEL_CONTENT_FL;

        wbuf[2] = port->ch.data_fmt | (port->ch.aux_fmt << 4);
        wbuf[3] = stream->bps/SLIM_SLOT_LEN_BITS;
        port->ch.state = SLIM_CH_STATE_CONTENT_DEFINED;

        return slim_do_transfer(sdev->ctrl, &txn);
}

static int slim_get_segdist_code(int ratem)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(segdist_codes); i++) {
                if (segdist_codes[i].ratem == ratem)
                        return segdist_codes[i].segdist_code;
        }

        return -EINVAL;
}

static int slim_define_channel(struct slim_stream_runtime *stream,
                                       struct slim_port *port)
{
        struct slim_device *sdev = stream->dev;
        u8 wbuf[4];
        struct slim_val_inf msg = {0, 4, NULL, wbuf, NULL};
        u8 mc = SLIM_MSG_MC_NEXT_DEFINE_CHANNEL;
        DEFINE_SLIM_LDEST_TXN(txn, mc, 8, stream->dev->laddr, &msg);

        port->ch.seg_dist = slim_get_segdist_code(stream->ratem);

        wbuf[0] = port->ch.id;
        wbuf[1] = port->ch.seg_dist & 0xFF;
        wbuf[2] = (stream->prot << 4) | ((port->ch.seg_dist & 0xF00) >> 8);
        if (stream->prot == SLIM_PROTO_ISO)
                wbuf[3] = stream->bps/SLIM_SLOT_LEN_BITS;
        else
                wbuf[3] = stream->bps/SLIM_SLOT_LEN_BITS + 1;

        port->ch.state = SLIM_CH_STATE_DEFINED;

        return slim_do_transfer(sdev->ctrl, &txn);
}

static int slim_activate_channel(struct slim_stream_runtime *stream,
                                 struct slim_port *port)
{
        struct slim_device *sdev = stream->dev;
        u8 wbuf[1];
        struct slim_val_inf msg = {0, 1, NULL, wbuf, NULL};
        u8 mc = SLIM_MSG_MC_NEXT_ACTIVATE_CHANNEL;
        DEFINE_SLIM_LDEST_TXN(txn, mc, 5, stream->dev->laddr, &msg);

        txn.msg->num_bytes = 1;
        txn.msg->wbuf = wbuf;
        wbuf[0] = port->ch.id;
        port->ch.state = SLIM_CH_STATE_ACTIVE;

        return slim_do_transfer(sdev->ctrl, &txn);
}

/**
 * slim_stream_enable() - Enable a prepared SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to enable
 *
 * This API will enable all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to trigger() start operation.
 */
int slim_stream_enable(struct slim_stream_runtime *stream)
{
        DEFINE_SLIM_BCAST_TXN(txn, SLIM_MSG_MC_BEGIN_RECONFIGURATION,
                                3, SLIM_LA_MANAGER, NULL);
        struct slim_controller *ctrl = stream->dev->ctrl;
        int ret, i;

        if (ctrl->enable_stream) {
                ret = ctrl->enable_stream(stream);
                if (ret)
                        return ret;

                for (i = 0; i < stream->num_ports; i++)
                        stream->ports[i].ch.state = SLIM_CH_STATE_ACTIVE;

                return ret;
        }

        ret = slim_do_transfer(ctrl, &txn);
        if (ret)
                return ret;

        /* define channels first before activating them */
        for (i = 0; i < stream->num_ports; i++) {
                struct slim_port *port = &stream->ports[i];

                slim_define_channel(stream, port);
                slim_define_channel_content(stream, port);
        }

        for (i = 0; i < stream->num_ports; i++) {
                struct slim_port *port = &stream->ports[i];

                slim_activate_channel(stream, port);
                port->state = SLIM_PORT_CONFIGURED;
        }
        txn.mc = SLIM_MSG_MC_RECONFIGURE_NOW;

        return slim_do_transfer(ctrl, &txn);
}
EXPORT_SYMBOL_GPL(slim_stream_enable);

/**
 * slim_stream_disable() - Disable a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to disable
 *
 * This API will disable all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to trigger() pause operation.
 */
int slim_stream_disable(struct slim_stream_runtime *stream)
{
        DEFINE_SLIM_BCAST_TXN(txn, SLIM_MSG_MC_BEGIN_RECONFIGURATION,
                                3, SLIM_LA_MANAGER, NULL);
        struct slim_controller *ctrl = stream->dev->ctrl;
        int ret, i;

        if (!stream->ports || !stream->num_ports)
                return -EINVAL;

        if (ctrl->disable_stream)
                ctrl->disable_stream(stream);

        ret = slim_do_transfer(ctrl, &txn);
        if (ret)
                return ret;

        for (i = 0; i < stream->num_ports; i++)
                slim_deactivate_remove_channel(stream, &stream->ports[i]);

        txn.mc = SLIM_MSG_MC_RECONFIGURE_NOW;

        return slim_do_transfer(ctrl, &txn);
}
EXPORT_SYMBOL_GPL(slim_stream_disable);

/**
 * slim_stream_unprepare() - Un-prepare a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to unprepare
 *
 * This API will un allocate all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to trigger() stop operation.
 */
int slim_stream_unprepare(struct slim_stream_runtime *stream)
{
        int i;

        if (!stream->ports || !stream->num_ports)
                return -EINVAL;

        for (i = 0; i < stream->num_ports; i++)
                slim_disconnect_port(stream, &stream->ports[i]);

        kfree(stream->ports);
        stream->ports = NULL;
        stream->num_ports = 0;

        return 0;
}
EXPORT_SYMBOL_GPL(slim_stream_unprepare);

/**
 * slim_stream_free() - Free a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to free
 *
 * This API will un allocate all the memory associated with
 * slim stream runtime, user is not allowed to make an dereference
 * to stream after this call.
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to shutdown() operation.
 */
int slim_stream_free(struct slim_stream_runtime *stream)
{
        struct slim_device *sdev = stream->dev;

        spin_lock(&sdev->stream_list_lock);
        list_del(&stream->node);
        spin_unlock(&sdev->stream_list_lock);

        kfree(stream->name);
        kfree(stream);

        return 0;
}
EXPORT_SYMBOL_GPL(slim_stream_free);