drivers/uio/msm_sharedmem.c

/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that 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.
 */

#define pr_fmt(fmt) "%s: " fmt, __func__

#include <linux/uio_driver.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>

#define DRIVER_NAME "msm_sharedmem"

static int msm_sharedmem_probe(struct platform_device *pdev)
{
	int ret = 0;
	struct uio_info *info = NULL;
	struct resource *clnt_res = NULL;

	/* Get the addresses from platform-data */
	if (!pdev->dev.of_node) {
		pr_err("Node not found\n");
		ret = -ENODEV;
		goto out;
	}
	clnt_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!clnt_res) {
		pr_err("resource not found\n");
		return -ENODEV;
	}

	info = devm_kzalloc(&pdev->dev, sizeof(struct uio_info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	info->name = clnt_res->name;
	info->version = "1.0";
	info->mem[0].addr = clnt_res->start;
	info->mem[0].size = resource_size(clnt_res);
	info->mem[0].memtype = UIO_MEM_PHYS;

	/* Setup device */
	ret = uio_register_device(&pdev->dev, info);
	if (ret)
		goto out;

	dev_set_drvdata(&pdev->dev, info);
	pr_debug("Device created for client '%s'\n", clnt_res->name);
out:
	return ret;
}

static int msm_sharedmem_remove(struct platform_device *pdev)
{
	struct uio_info *info = dev_get_drvdata(&pdev->dev);

	uio_unregister_device(info);

	return 0;
}

static struct of_device_id msm_sharedmem_of_match[] = {
	{.compatible = "qcom,sharedmem-uio",},
	{},
};
MODULE_DEVICE_TABLE(of, msm_sharedmem_of_match);

static struct platform_driver msm_sharedmem_driver = {
	.probe          = msm_sharedmem_probe,
	.remove         = msm_sharedmem_remove,
	.driver         = {
		.name   = DRIVER_NAME,
		.owner	= THIS_MODULE,
		.of_match_table = msm_sharedmem_of_match,
	},
};

module_platform_driver(msm_sharedmem_driver);
MODULE_LICENSE("GPL v2");