1 /*
2  * Copyright (C) 2013 - Virtual Open Systems
3  * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License, version 2, as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/vfio.h>
18 #include <linux/amba/bus.h>
19 
20 #include "vfio_platform_private.h"
21 
22 #define DRIVER_VERSION  "0.10"
23 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
24 #define DRIVER_DESC     "VFIO for AMBA devices - User Level meta-driver"
25 
26 /* probing devices from the AMBA bus */
27 
28 static struct resource *get_amba_resource(struct vfio_platform_device *vdev,
29 					  int i)
30 {
31 	struct amba_device *adev = (struct amba_device *) vdev->opaque;
32 
33 	if (i == 0)
34 		return &adev->res;
35 
36 	return NULL;
37 }
38 
39 static int get_amba_irq(struct vfio_platform_device *vdev, int i)
40 {
41 	struct amba_device *adev = (struct amba_device *) vdev->opaque;
42 	int ret = 0;
43 
44 	if (i < AMBA_NR_IRQS)
45 		ret = adev->irq[i];
46 
47 	/* zero is an unset IRQ for AMBA devices */
48 	return ret ? ret : -ENXIO;
49 }
50 
51 static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
52 {
53 	struct vfio_platform_device *vdev;
54 	int ret;
55 
56 	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
57 	if (!vdev)
58 		return -ENOMEM;
59 
60 	vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
61 	if (!vdev->name) {
62 		kfree(vdev);
63 		return -ENOMEM;
64 	}
65 
66 	vdev->opaque = (void *) adev;
67 	vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
68 	vdev->get_resource = get_amba_resource;
69 	vdev->get_irq = get_amba_irq;
70 	vdev->parent_module = THIS_MODULE;
71 	vdev->reset_required = false;
72 
73 	ret = vfio_platform_probe_common(vdev, &adev->dev);
74 	if (ret) {
75 		kfree(vdev->name);
76 		kfree(vdev);
77 	}
78 
79 	return ret;
80 }
81 
82 static int vfio_amba_remove(struct amba_device *adev)
83 {
84 	struct vfio_platform_device *vdev;
85 
86 	vdev = vfio_platform_remove_common(&adev->dev);
87 	if (vdev) {
88 		kfree(vdev->name);
89 		kfree(vdev);
90 		return 0;
91 	}
92 
93 	return -EINVAL;
94 }
95 
96 static struct amba_id pl330_ids[] = {
97 	{ 0, 0 },
98 };
99 
100 MODULE_DEVICE_TABLE(amba, pl330_ids);
101 
102 static struct amba_driver vfio_amba_driver = {
103 	.probe = vfio_amba_probe,
104 	.remove = vfio_amba_remove,
105 	.id_table = pl330_ids,
106 	.drv = {
107 		.name = "vfio-amba",
108 		.owner = THIS_MODULE,
109 	},
110 };
111 
112 module_amba_driver(vfio_amba_driver);
113 
114 MODULE_VERSION(DRIVER_VERSION);
115 MODULE_LICENSE("GPL v2");
116 MODULE_AUTHOR(DRIVER_AUTHOR);
117 MODULE_DESCRIPTION(DRIVER_DESC);
118