linux/sound/soc/sof/sof-client-ipc-kernel-injector.c

// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright(c) 2023 Google Inc
//
// Author: Curtis Malainey <[email protected]>
//

#include <linux/auxiliary_bus.h>
#include <linux/debugfs.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <sound/sof/header.h>

#include "sof-client.h"

#define SOF_IPC_CLIENT_SUSPEND_DELAY_MS …

struct sof_msg_inject_priv { … };

static int sof_msg_inject_dfs_open(struct inode *inode, struct file *file)
{ … }

static ssize_t sof_kernel_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;
	struct sof_ipc_cmd_hdr *hdr = priv->kernel_buffer;
	struct device *dev = &cdev->auxdev.dev;
	ssize_t size;
	int ret;

	if (*ppos)
		return 0;

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

	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;
	}

	sof_client_ipc_rx_message(cdev, hdr, priv->kernel_buffer);

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

	return count;
};

static int sof_msg_inject_dfs_release(struct inode *inode, struct file *file)
{ … }

static const struct file_operations sof_kernel_msg_inject_fops = …;

static int sof_msg_inject_probe(struct auxiliary_device *auxdev,
				const struct auxiliary_device_id *id)
{ … }

static void sof_msg_inject_remove(struct auxiliary_device *auxdev)
{ … }

static const struct auxiliary_device_id sof_msg_inject_client_id_table[] = …;
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 = …;

module_auxiliary_driver(…) …;

MODULE_LICENSE(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_IMPORT_NS(…);