// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright(c) 2022 Intel Corporation
//
// Author: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
//

#include <linux/auxiliary_bus.h>
#include <linux/completion.h>
#include <linux/debugfs.h>
#include <linux/ktime.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <sound/sof/header.h>
#include <sound/sof/ipc4/header.h>

#include "sof-client.h"

#define SOF_IPC_CLIENT_SUSPEND_DELAY_MS 3000

struct sof_msg_inject_priv {
        struct dentry *dfs_file;
        size_t max_msg_size;
        enum sof_ipc_type ipc_type;

        void *tx_buffer;
        void *rx_buffer;
};

static int sof_msg_inject_dfs_open(struct inode *inode, struct file *file)
{
        struct sof_client_dev *cdev = inode->i_private;
        int ret;

        if (sof_client_get_fw_state(cdev) == SOF_FW_CRASHED)
                return -ENODEV;

        ret = debugfs_file_get(file->f_path.dentry);
        if (unlikely(ret))
                return ret;

        ret = simple_open(inode, file);
        if (ret)
                debugfs_file_put(file->f_path.dentry);

        return ret;
}

static ssize_t sof_msg_inject_dfs_read(struct file *file, char __user *buffer,
                                       size_t count, loff_t *ppos)
{
        struct sof_client_dev *cdev = file->private_data;
        struct sof_msg_inject_priv *priv = cdev->data;
        struct sof_ipc_reply *rhdr = priv->rx_buffer;

        if (!rhdr->hdr.size || !count || *ppos)
                return 0;

        if (count > rhdr->hdr.size)
                count = rhdr->hdr.size;

        if (copy_to_user(buffer, priv->rx_buffer, count))
                return -EFAULT;

        *ppos += count;
        return count;
}

static ssize_t sof_msg_inject_ipc4_dfs_read(struct file *file,
                                            char __user *buffer,
                                            size_t count, loff_t *ppos)
{
        struct sof_client_dev *cdev = file->private_data;
        struct sof_msg_inject_priv *priv = cdev->data;
        struct sof_ipc4_msg *ipc4_msg = priv->rx_buffer;
        size_t header_size = sizeof(ipc4_msg->header_u64);
        size_t remaining;

        if (!ipc4_msg->header_u64 || !count || *ppos)
                return 0;

        /* we need space for the header at minimum (u64) */
        if (count < header_size)
                return -ENOSPC;

        remaining = header_size;

        /* Only get large config have payload */
        if (SOF_IPC4_MSG_IS_MODULE_MSG(ipc4_msg->primary) &&
            (SOF_IPC4_MSG_TYPE_GET(ipc4_msg->primary) == SOF_IPC4_MOD_LARGE_CONFIG_GET))
                remaining += ipc4_msg->data_size;

        if (count > remaining)
                count = remaining;
        else if (count < remaining)
                remaining = count;

        /* copy the header first */
        if (copy_to_user(buffer, &ipc4_msg->header_u64, header_size))
                return -EFAULT;

        *ppos += header_size;
        remaining -= header_size;

        if (!remaining)
                return count;

        if (remaining > ipc4_msg->data_size)
                remaining = ipc4_msg->data_size;

        /* Copy the payload */
        if (copy_to_user(buffer + *ppos, ipc4_msg->data_ptr, remaining))
                return -EFAULT;

        *ppos += remaining;
        return count;
}

static int sof_msg_inject_send_message(struct sof_client_dev *cdev)
{
        struct sof_msg_inject_priv *priv = cdev->data;
        struct device *dev = &cdev->auxdev.dev;
        int ret, err;

        ret = pm_runtime_resume_and_get(dev);
        if (ret < 0 && ret != -EACCES) {
                dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
                return ret;
        }

        ret = sof_client_boot_dsp(cdev);
        if (!ret) {
                /* send the message */
                ret = sof_client_ipc_tx_message(cdev, priv->tx_buffer,
                                                priv->rx_buffer,
                                                priv->max_msg_size);
                if (ret)
                        dev_err(dev, "IPC message send failed: %d\n", ret);
        }

        err = pm_runtime_put_autosuspend(dev);
        if (err < 0)
                dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);

        return ret;
}

static ssize_t sof_msg_inject_dfs_write(struct file *file, const char __user *buffer,
                                        size_t count, loff_t *ppos)
{
        struct sof_client_dev *cdev = file->private_data;
        struct sof_msg_inject_priv *priv = cdev->data;
        ssize_t size;
        int ret;

        if (*ppos)
                return 0;

        size = simple_write_to_buffer(priv->tx_buffer, priv->max_msg_size,
                                      ppos, buffer, count);
        if (size < 0)
                return size;
        if (size != count)
                return -EFAULT;

        memset(priv->rx_buffer, 0, priv->max_msg_size);

        ret = sof_msg_inject_send_message(cdev);

        /* return the error code if test failed */
        if (ret < 0)
                size = ret;

        return size;
};

static ssize_t sof_msg_inject_ipc4_dfs_write(struct file *file,
                                             const char __user *buffer,
                                             size_t count, loff_t *ppos)
{
        struct sof_client_dev *cdev = file->private_data;
        struct sof_msg_inject_priv *priv = cdev->data;
        struct sof_ipc4_msg *ipc4_msg = priv->tx_buffer;
        size_t data_size;
        int ret;

        if (*ppos)
                return 0;

        if (count < sizeof(ipc4_msg->header_u64))
                return -EINVAL;

        /* copy the header first */
        if (copy_from_user(&ipc4_msg->header_u64, buffer,
                           sizeof(ipc4_msg->header_u64)))
                return -EFAULT;

        data_size = count - sizeof(ipc4_msg->header_u64);
        if (data_size > priv->max_msg_size)
                return -EINVAL;

        /* Copy the payload */
        if (copy_from_user(ipc4_msg->data_ptr,
                           buffer + sizeof(ipc4_msg->header_u64), data_size))
                return -EFAULT;

        ipc4_msg->data_size = data_size;

        /* Initialize the reply storage */
        ipc4_msg = priv->rx_buffer;
        ipc4_msg->header_u64 = 0;
        ipc4_msg->data_size = priv->max_msg_size;
        memset(ipc4_msg->data_ptr, 0, priv->max_msg_size);

        ret = sof_msg_inject_send_message(cdev);

        /* return the error code if test failed */
        if (ret < 0)
                return ret;

        return count;
};

static int sof_msg_inject_dfs_release(struct inode *inode, struct file *file)
{
        debugfs_file_put(file->f_path.dentry);

        return 0;
}

static const struct file_operations sof_msg_inject_fops = {
        .open = sof_msg_inject_dfs_open,
        .read = sof_msg_inject_dfs_read,
        .write = sof_msg_inject_dfs_write,
        .llseek = default_llseek,
        .release = sof_msg_inject_dfs_release,

        .owner = THIS_MODULE,
};

static const struct file_operations sof_msg_inject_ipc4_fops = {
        .open = sof_msg_inject_dfs_open,
        .read = sof_msg_inject_ipc4_dfs_read,
        .write = sof_msg_inject_ipc4_dfs_write,
        .llseek = default_llseek,
        .release = sof_msg_inject_dfs_release,

        .owner = THIS_MODULE,
};

static int sof_msg_inject_probe(struct auxiliary_device *auxdev,
                                const struct auxiliary_device_id *id)
{
        struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
        struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
        static const struct file_operations *fops;
        struct device *dev = &auxdev->dev;
        struct sof_msg_inject_priv *priv;
        size_t alloc_size;

        /* allocate memory for client data */
        priv = devm_kzalloc(&auxdev->dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->ipc_type = sof_client_get_ipc_type(cdev);
        priv->max_msg_size = sof_client_get_ipc_max_payload_size(cdev);
        alloc_size = priv->max_msg_size;

        if (priv->ipc_type == SOF_IPC_TYPE_4)
                alloc_size += sizeof(struct sof_ipc4_msg);

        priv->tx_buffer = devm_kmalloc(dev, alloc_size, GFP_KERNEL);
        priv->rx_buffer = devm_kzalloc(dev, alloc_size, GFP_KERNEL);
        if (!priv->tx_buffer || !priv->rx_buffer)
                return -ENOMEM;

        if (priv->ipc_type == SOF_IPC_TYPE_4) {
                struct sof_ipc4_msg *ipc4_msg;

                ipc4_msg = priv->tx_buffer;
                ipc4_msg->data_ptr = priv->tx_buffer + sizeof(struct sof_ipc4_msg);

                ipc4_msg = priv->rx_buffer;
                ipc4_msg->data_ptr = priv->rx_buffer + sizeof(struct sof_ipc4_msg);

                fops = &sof_msg_inject_ipc4_fops;
        } else {
                fops = &sof_msg_inject_fops;
        }

        cdev->data = priv;

        priv->dfs_file = debugfs_create_file("ipc_msg_inject", 0644, debugfs_root,
                                             cdev, fops);

        /* enable runtime PM */
        pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
        pm_runtime_use_autosuspend(dev);
        pm_runtime_enable(dev);
        pm_runtime_mark_last_busy(dev);
        pm_runtime_idle(dev);

        return 0;
}

static void sof_msg_inject_remove(struct auxiliary_device *auxdev)
{
        struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
        struct sof_msg_inject_priv *priv = cdev->data;

        pm_runtime_disable(&auxdev->dev);

        debugfs_remove(priv->dfs_file);
}

static const struct auxiliary_device_id sof_msg_inject_client_id_table[] = {
        { .name = "snd_sof.msg_injector" },
        {},
};
MODULE_DEVICE_TABLE(auxiliary, sof_msg_inject_client_id_table);

/*
 * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
 * type are enough to ensure that the parent SOF device resumes to bring the DSP
 * back to D0.
 * Driver name will be set based on KBUILD_MODNAME.
 */
static struct auxiliary_driver sof_msg_inject_client_drv = {
        .probe = sof_msg_inject_probe,
        .remove = sof_msg_inject_remove,

        .id_table = sof_msg_inject_client_id_table,
};

module_auxiliary_driver(sof_msg_inject_client_drv);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SOF IPC Message Injector Client Driver");
MODULE_IMPORT_NS("SND_SOC_SOF_CLIENT");