// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) STMicroelectronics SA 2015
 * Author: Hugues Fruchet <hugues.fruchet@st.com> for STMicroelectronics.
 */

#include <linux/rpmsg.h>

#include "delta.h"
#include "delta-ipc.h"
#include "delta-mem.h"

#define IPC_TIMEOUT 100
#define IPC_SANITY_TAG 0xDEADBEEF

enum delta_ipc_fw_command {
        DELTA_IPC_OPEN,
        DELTA_IPC_SET_STREAM,
        DELTA_IPC_DECODE,
        DELTA_IPC_CLOSE
};

#define to_rpmsg_driver(__drv) container_of(__drv, struct rpmsg_driver, drv)
#define to_delta(__d) container_of(__d, struct delta_dev, rpmsg_driver)

#define to_ctx(hdl) ((struct delta_ipc_ctx *)hdl)
#define to_pctx(ctx) container_of(ctx, struct delta_ctx, ipc_ctx)

struct delta_ipc_header_msg {
        u32 tag;
        void *host_hdl;
        u32 copro_hdl;
        u32 command;
};

#define to_host_hdl(ctx) ((void *)ctx)

#define msg_to_ctx(msg) ((struct delta_ipc_ctx *)(msg)->header.host_hdl)
#define msg_to_copro_hdl(msg) ((msg)->header.copro_hdl)

static inline dma_addr_t to_paddr(struct delta_ipc_ctx *ctx, void *vaddr)
{
        return (ctx->ipc_buf->paddr + (vaddr - ctx->ipc_buf->vaddr));
}

static inline bool is_valid_data(struct delta_ipc_ctx *ctx,
                                 void *data, u32 size)
{
        return ((data >= ctx->ipc_buf->vaddr) &&
                ((data + size) <= (ctx->ipc_buf->vaddr + ctx->ipc_buf->size)));
}

/*
 * IPC shared memory (@ipc_buf_size, @ipc_buf_paddr) is sent to copro
 * at each instance opening. This memory is allocated by IPC client
 * and given through delta_ipc_open(). All messages parameters
 * (open, set_stream, decode) will have their phy address within
 * this IPC shared memory, avoiding de-facto recopies inside delta-ipc.
 * All the below messages structures are used on both host and firmware
 * side and are packed (use only of 32 bits size fields in messages
 * structures to ensure packing):
 * - struct delta_ipc_open_msg
 * - struct delta_ipc_set_stream_msg
 * - struct delta_ipc_decode_msg
 * - struct delta_ipc_close_msg
 * - struct delta_ipc_cb_msg
 */
struct delta_ipc_open_msg {
        struct delta_ipc_header_msg header;
        u32 ipc_buf_size;
        dma_addr_t ipc_buf_paddr;
        char name[32];
        u32 param_size;
        dma_addr_t param_paddr;
};

struct delta_ipc_set_stream_msg {
        struct delta_ipc_header_msg header;
        u32 param_size;
        dma_addr_t param_paddr;
};

struct delta_ipc_decode_msg {
        struct delta_ipc_header_msg header;
        u32 param_size;
        dma_addr_t param_paddr;
        u32 status_size;
        dma_addr_t status_paddr;
};

struct delta_ipc_close_msg {
        struct delta_ipc_header_msg header;
};

struct delta_ipc_cb_msg {
        struct delta_ipc_header_msg header;
        int err;
};

static void build_msg_header(struct delta_ipc_ctx *ctx,
                             enum delta_ipc_fw_command command,
                             struct delta_ipc_header_msg *header)
{
        header->tag = IPC_SANITY_TAG;
        header->host_hdl = to_host_hdl(ctx);
        header->copro_hdl = ctx->copro_hdl;
        header->command = command;
}

int delta_ipc_open(struct delta_ctx *pctx, const char *name,
                   struct delta_ipc_param *param, u32 ipc_buf_size,
                   struct delta_buf **ipc_buf, void **hdl)
{
        struct delta_dev *delta = pctx->dev;
        struct rpmsg_device *rpmsg_device = delta->rpmsg_device;
        struct delta_ipc_ctx *ctx = &pctx->ipc_ctx;
        struct delta_ipc_open_msg msg;
        struct delta_buf *buf = &ctx->ipc_buf_struct;
        int ret;

        if (!rpmsg_device) {
                dev_err(delta->dev,
                        "%s   ipc: failed to open, rpmsg is not initialized\n",
                        pctx->name);
                pctx->sys_errors++;
                return -EINVAL;
        }

        if (!name) {
                dev_err(delta->dev,
                        "%s   ipc: failed to open, no name given\n",
                        pctx->name);
                return -EINVAL;
        }

        if (!param || !param->data || !param->size) {
                dev_err(delta->dev,
                        "%s  ipc: failed to open, empty parameter\n",
                        pctx->name);
                return -EINVAL;
        }

        if (!ipc_buf_size) {
                dev_err(delta->dev,
                        "%s   ipc: failed to open, no size given for ipc buffer\n",
                        pctx->name);
                return -EINVAL;
        }

        if (param->size > ipc_buf_size) {
                dev_err(delta->dev,
                        "%s   ipc: failed to open, too large ipc parameter (%d bytes while max %d expected)\n",
                        pctx->name,
                        param->size, ctx->ipc_buf->size);
                return -EINVAL;
        }

        /* init */
        init_completion(&ctx->done);

        /*
         * allocation of contiguous buffer for
         * data of commands exchanged between
         * host and firmware coprocessor
         */
        ret = hw_alloc(pctx, ipc_buf_size,
                       "ipc data buffer", buf);
        if (ret)
                return ret;
        ctx->ipc_buf = buf;

        /* build rpmsg message */
        build_msg_header(ctx, DELTA_IPC_OPEN, &msg.header);

        msg.ipc_buf_size = ipc_buf_size;
        msg.ipc_buf_paddr = ctx->ipc_buf->paddr;

        strscpy(msg.name, name, sizeof(msg.name));

        msg.param_size = param->size;
        memcpy(ctx->ipc_buf->vaddr, param->data, msg.param_size);
        msg.param_paddr = ctx->ipc_buf->paddr;

        /* send it */
        ret = rpmsg_send(rpmsg_device->ept, &msg, sizeof(msg));
        if (ret) {
                dev_err(delta->dev,
                        "%s   ipc: failed to open, rpmsg_send failed (%d) for DELTA_IPC_OPEN (name=%s, size=%d, data=%p)\n",
                        pctx->name,
                        ret, name, param->size, param->data);
                goto err;
        }

        /* wait for acknowledge */
        if (!wait_for_completion_timeout
            (&ctx->done, msecs_to_jiffies(IPC_TIMEOUT))) {
                dev_err(delta->dev,
                        "%s   ipc: failed to open, timeout waiting for DELTA_IPC_OPEN callback (name=%s, size=%d, data=%p)\n",
                        pctx->name,
                        name, param->size, param->data);
                ret = -ETIMEDOUT;
                goto err;
        }

        /* command completed, check error */
        if (ctx->cb_err) {
                dev_err(delta->dev,
                        "%s   ipc: failed to open, DELTA_IPC_OPEN completed but with error (%d) (name=%s, size=%d, data=%p)\n",
                        pctx->name,
                        ctx->cb_err, name, param->size, param->data);
                ret = -EIO;
                goto err;
        }

        *ipc_buf = ctx->ipc_buf;
        *hdl = (void *)ctx;

        return 0;

err:
        pctx->sys_errors++;
        hw_free(pctx, ctx->ipc_buf);
        ctx->ipc_buf = NULL;

        return ret;
};

int delta_ipc_set_stream(void *hdl, struct delta_ipc_param *param)
{
        struct delta_ipc_ctx *ctx = to_ctx(hdl);
        struct delta_ctx *pctx = to_pctx(ctx);
        struct delta_dev *delta = pctx->dev;
        struct rpmsg_device *rpmsg_device = delta->rpmsg_device;
        struct delta_ipc_set_stream_msg msg;
        int ret;

        if (!hdl) {
                dev_err(delta->dev,
                        "%s   ipc: failed to set stream, invalid ipc handle\n",
                        pctx->name);
                return -EINVAL;
        }

        if (!rpmsg_device) {
                dev_err(delta->dev,
                        "%s   ipc: failed to set stream, rpmsg is not initialized\n",
                        pctx->name);
                return -EINVAL;
        }

        if (!param || !param->data || !param->size) {
                dev_err(delta->dev,
                        "%s  ipc: failed to set stream, empty parameter\n",
                        pctx->name);
                return -EINVAL;
        }

        if (param->size > ctx->ipc_buf->size) {
                dev_err(delta->dev,
                        "%s   ipc: failed to set stream, too large ipc parameter(%d bytes while max %d expected)\n",
                        pctx->name,
                        param->size, ctx->ipc_buf->size);
                return -EINVAL;
        }

        if (!is_valid_data(ctx, param->data, param->size)) {
                dev_err(delta->dev,
                        "%s   ipc: failed to set stream, parameter is not in expected address range (size=%d, data=%p not in %p..%p)\n",
                        pctx->name,
                        param->size,
                        param->data,
                        ctx->ipc_buf->vaddr,
                        ctx->ipc_buf->vaddr + ctx->ipc_buf->size - 1);
                return -EINVAL;
        }

        /* build rpmsg message */
        build_msg_header(ctx, DELTA_IPC_SET_STREAM, &msg.header);

        msg.param_size = param->size;
        msg.param_paddr = to_paddr(ctx, param->data);

        /* send it */
        ret = rpmsg_send(rpmsg_device->ept, &msg, sizeof(msg));
        if (ret) {
                dev_err(delta->dev,
                        "%s   ipc: failed to set stream, rpmsg_send failed (%d) for DELTA_IPC_SET_STREAM (size=%d, data=%p)\n",
                        pctx->name,
                        ret, param->size, param->data);
                pctx->sys_errors++;
                return ret;
        }

        /* wait for acknowledge */
        if (!wait_for_completion_timeout
            (&ctx->done, msecs_to_jiffies(IPC_TIMEOUT))) {
                dev_err(delta->dev,
                        "%s   ipc: failed to set stream, timeout waiting for DELTA_IPC_SET_STREAM callback (size=%d, data=%p)\n",
                        pctx->name,
                        param->size, param->data);
                pctx->sys_errors++;
                return -ETIMEDOUT;
        }

        /* command completed, check status */
        if (ctx->cb_err) {
                dev_err(delta->dev,
                        "%s   ipc: failed to set stream, DELTA_IPC_SET_STREAM completed but with error (%d) (size=%d, data=%p)\n",
                        pctx->name,
                        ctx->cb_err, param->size, param->data);
                pctx->sys_errors++;
                return -EIO;
        }

        return 0;
}

int delta_ipc_decode(void *hdl, struct delta_ipc_param *param,
                     struct delta_ipc_param *status)
{
        struct delta_ipc_ctx *ctx = to_ctx(hdl);
        struct delta_ctx *pctx = to_pctx(ctx);
        struct delta_dev *delta = pctx->dev;
        struct rpmsg_device *rpmsg_device = delta->rpmsg_device;
        struct delta_ipc_decode_msg msg;
        int ret;

        if (!hdl) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, invalid ipc handle\n",
                        pctx->name);
                return -EINVAL;
        }

        if (!rpmsg_device) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, rpmsg is not initialized\n",
                        pctx->name);
                return -EINVAL;
        }

        if (!param || !param->data || !param->size) {
                dev_err(delta->dev,
                        "%s  ipc: failed to decode, empty parameter\n",
                        pctx->name);
                return -EINVAL;
        }

        if (!status || !status->data || !status->size) {
                dev_err(delta->dev,
                        "%s  ipc: failed to decode, empty status\n",
                        pctx->name);
                return -EINVAL;
        }

        if (param->size + status->size > ctx->ipc_buf->size) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, too large ipc parameter (%d bytes (param) + %d bytes (status) while max %d expected)\n",
                        pctx->name,
                        param->size,
                        status->size,
                        ctx->ipc_buf->size);
                return -EINVAL;
        }

        if (!is_valid_data(ctx, param->data, param->size)) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, parameter is not in expected address range (size=%d, data=%p not in %p..%p)\n",
                        pctx->name,
                        param->size,
                        param->data,
                        ctx->ipc_buf->vaddr,
                        ctx->ipc_buf->vaddr + ctx->ipc_buf->size - 1);
                return -EINVAL;
        }

        if (!is_valid_data(ctx, status->data, status->size)) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, status is not in expected address range (size=%d, data=%p not in %p..%p)\n",
                        pctx->name,
                        status->size,
                        status->data,
                        ctx->ipc_buf->vaddr,
                        ctx->ipc_buf->vaddr + ctx->ipc_buf->size - 1);
                return -EINVAL;
        }

        /* build rpmsg message */
        build_msg_header(ctx, DELTA_IPC_DECODE, &msg.header);

        msg.param_size = param->size;
        msg.param_paddr = to_paddr(ctx, param->data);

        msg.status_size = status->size;
        msg.status_paddr = to_paddr(ctx, status->data);

        /* send it */
        ret = rpmsg_send(rpmsg_device->ept, &msg, sizeof(msg));
        if (ret) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, rpmsg_send failed (%d) for DELTA_IPC_DECODE (size=%d, data=%p)\n",
                        pctx->name,
                        ret, param->size, param->data);
                pctx->sys_errors++;
                return ret;
        }

        /* wait for acknowledge */
        if (!wait_for_completion_timeout
            (&ctx->done, msecs_to_jiffies(IPC_TIMEOUT))) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, timeout waiting for DELTA_IPC_DECODE callback (size=%d, data=%p)\n",
                        pctx->name,
                        param->size, param->data);
                pctx->sys_errors++;
                return -ETIMEDOUT;
        }

        /* command completed, check status */
        if (ctx->cb_err) {
                dev_err(delta->dev,
                        "%s   ipc: failed to decode, DELTA_IPC_DECODE completed but with error (%d) (size=%d, data=%p)\n",
                        pctx->name,
                        ctx->cb_err, param->size, param->data);
                pctx->sys_errors++;
                return -EIO;
        }

        return 0;
};

void delta_ipc_close(void *hdl)
{
        struct delta_ipc_ctx *ctx = to_ctx(hdl);
        struct delta_ctx *pctx = to_pctx(ctx);
        struct delta_dev *delta = pctx->dev;
        struct rpmsg_device *rpmsg_device = delta->rpmsg_device;
        struct delta_ipc_close_msg msg;
        int ret;

        if (!hdl) {
                dev_err(delta->dev,
                        "%s   ipc: failed to close, invalid ipc handle\n",
                        pctx->name);
                return;
        }

        if (ctx->ipc_buf) {
                hw_free(pctx, ctx->ipc_buf);
                ctx->ipc_buf = NULL;
        }

        if (!rpmsg_device) {
                dev_err(delta->dev,
                        "%s   ipc: failed to close, rpmsg is not initialized\n",
                        pctx->name);
                return;
        }

        /* build rpmsg message */
        build_msg_header(ctx, DELTA_IPC_CLOSE, &msg.header);

        /* send it */
        ret = rpmsg_send(rpmsg_device->ept, &msg, sizeof(msg));
        if (ret) {
                dev_err(delta->dev,
                        "%s   ipc: failed to close, rpmsg_send failed (%d) for DELTA_IPC_CLOSE\n",
                        pctx->name, ret);
                pctx->sys_errors++;
                return;
        }

        /* wait for acknowledge */
        if (!wait_for_completion_timeout
            (&ctx->done, msecs_to_jiffies(IPC_TIMEOUT))) {
                dev_err(delta->dev,
                        "%s   ipc: failed to close, timeout waiting for DELTA_IPC_CLOSE callback\n",
                        pctx->name);
                pctx->sys_errors++;
                return;
        }

        /* command completed, check status */
        if (ctx->cb_err) {
                dev_err(delta->dev,
                        "%s   ipc: failed to close, DELTA_IPC_CLOSE completed but with error (%d)\n",
                        pctx->name, ctx->cb_err);
                pctx->sys_errors++;
        }
};

static int delta_ipc_cb(struct rpmsg_device *rpdev, void *data,
                        int len, void *priv, u32 src)
{
        struct delta_ipc_ctx *ctx;
        struct delta_ipc_cb_msg *msg;

        /* sanity check */
        if (!rpdev) {
                dev_err(NULL, "rpdev is NULL\n");
                return -EINVAL;
        }

        if (!data || !len) {
                dev_err(&rpdev->dev,
                        "unexpected empty message received from src=%d\n", src);
                return -EINVAL;
        }

        if (len != sizeof(*msg)) {
                dev_err(&rpdev->dev,
                        "unexpected message length received from src=%d (received %d bytes while %zu bytes expected)\n",
                        len, src, sizeof(*msg));
                return -EINVAL;
        }

        msg = (struct delta_ipc_cb_msg *)data;
        if (msg->header.tag != IPC_SANITY_TAG) {
                dev_err(&rpdev->dev,
                        "unexpected message tag received from src=%d (received %x tag while %x expected)\n",
                        src, msg->header.tag, IPC_SANITY_TAG);
                return -EINVAL;
        }

        ctx = msg_to_ctx(msg);
        if (!ctx) {
                dev_err(&rpdev->dev,
                        "unexpected message with NULL host_hdl received from src=%d\n",
                        src);
                return -EINVAL;
        }

        /*
         * if not already known, save copro instance context
         * to ensure re-entrance on copro side
         */
        if (!ctx->copro_hdl)
                ctx->copro_hdl = msg_to_copro_hdl(msg);

        /*
         * all is fine,
         * update status & complete command
         */
        ctx->cb_err = msg->err;
        complete(&ctx->done);

        return 0;
}

static int delta_ipc_probe(struct rpmsg_device *rpmsg_device)
{
        struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpmsg_device->dev.driver);
        struct delta_dev *delta = to_delta(rpdrv);

        delta->rpmsg_device = rpmsg_device;

        return 0;
}

static void delta_ipc_remove(struct rpmsg_device *rpmsg_device)
{
        struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpmsg_device->dev.driver);
        struct delta_dev *delta = to_delta(rpdrv);

        delta->rpmsg_device = NULL;
}

static struct rpmsg_device_id delta_ipc_device_id_table[] = {
        {.name = "rpmsg-delta"},
        {},
};

static struct rpmsg_driver delta_rpmsg_driver = {
        .drv = {.name = KBUILD_MODNAME},
        .id_table = delta_ipc_device_id_table,
        .probe = delta_ipc_probe,
        .callback = delta_ipc_cb,
        .remove = delta_ipc_remove,
};

int delta_ipc_init(struct delta_dev *delta)
{
        delta->rpmsg_driver = delta_rpmsg_driver;

        return register_rpmsg_driver(&delta->rpmsg_driver);
}

void delta_ipc_exit(struct delta_dev *delta)
{
        unregister_rpmsg_driver(&delta->rpmsg_driver);
}