aboutsummaryrefslogtreecommitdiff
path: root/samples/vfio-mdev/mdpy-fb.c
blob: 9ec93d90e8a5a647f1e8ddce1ed2f005abdfeeee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
// SPDX-License-Identifier: GPL-2.0
/*
 * Framebuffer driver for mdpy (mediated virtual pci display device).
 *
 * See mdpy-defs.h for device specs
 *
 *   (c) Gerd Hoffmann <kraxel@redhat.com>
 *
 * Using some code snippets from simplefb and cirrusfb.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 */
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <drm/drm_fourcc.h>
#include "mdpy-defs.h"

static const struct fb_fix_screeninfo mdpy_fb_fix = {
	.id		= "mdpy-fb",
	.type		= FB_TYPE_PACKED_PIXELS,
	.visual		= FB_VISUAL_TRUECOLOR,
	.accel		= FB_ACCEL_NONE,
};

static const struct fb_var_screeninfo mdpy_fb_var = {
	.height		= -1,
	.width		= -1,
	.activate	= FB_ACTIVATE_NOW,
	.vmode		= FB_VMODE_NONINTERLACED,

	.bits_per_pixel = 32,
	.transp.offset	= 24,
	.red.offset	= 16,
	.green.offset	= 8,
	.blue.offset	= 0,
	.transp.length	= 8,
	.red.length	= 8,
	.green.length	= 8,
	.blue.length	= 8,
};

#define PSEUDO_PALETTE_SIZE 16

struct mdpy_fb_par {
	u32 palette[PSEUDO_PALETTE_SIZE];
};

static int mdpy_fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
			      u_int transp, struct fb_info *info)
{
	u32 *pal = info->pseudo_palette;
	u32 cr = red >> (16 - info->var.red.length);
	u32 cg = green >> (16 - info->var.green.length);
	u32 cb = blue >> (16 - info->var.blue.length);
	u32 value, mask;

	if (regno >= PSEUDO_PALETTE_SIZE)
		return -EINVAL;

	value = (cr << info->var.red.offset) |
		(cg << info->var.green.offset) |
		(cb << info->var.blue.offset);
	if (info->var.transp.length > 0) {
		mask = (1 << info->var.transp.length) - 1;
		mask <<= info->var.transp.offset;
		value |= mask;
	}
	pal[regno] = value;

	return 0;
}

static void mdpy_fb_destroy(struct fb_info *info)
{
	if (info->screen_base)
		iounmap(info->screen_base);
}

static const struct fb_ops mdpy_fb_ops = {
	.owner		= THIS_MODULE,
	.fb_destroy	= mdpy_fb_destroy,
	.fb_setcolreg	= mdpy_fb_setcolreg,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
};

static int mdpy_fb_probe(struct pci_dev *pdev,
			 const struct pci_device_id *ent)
{
	struct fb_info *info;
	struct mdpy_fb_par *par;
	u32 format, width, height;
	int ret;

	ret = pci_enable_device(pdev);
	if (ret < 0)
		return ret;

	ret = pci_request_regions(pdev, "mdpy-fb");
	if (ret < 0)
		return ret;

	pci_read_config_dword(pdev, MDPY_FORMAT_OFFSET, &format);
	pci_read_config_dword(pdev, MDPY_WIDTH_OFFSET,	&width);
	pci_read_config_dword(pdev, MDPY_HEIGHT_OFFSET, &height);
	if (format != DRM_FORMAT_XRGB8888) {
		pci_err(pdev, "format mismatch (0x%x != 0x%x)\n",
			format, DRM_FORMAT_XRGB8888);
		ret = -EINVAL;
		goto err_release_regions;
	}
	if (width < 100	 || width > 10000) {
		pci_err(pdev, "width (%d) out of range\n", width);
		ret = -EINVAL;
		goto err_release_regions;
	}
	if (height < 100 || height > 10000) {
		pci_err(pdev, "height (%d) out of range\n", height);
		ret = -EINVAL;
		goto err_release_regions;
	}
	pci_info(pdev, "mdpy found: %dx%d framebuffer\n",
		 width, height);

	info = framebuffer_alloc(sizeof(struct mdpy_fb_par), &pdev->dev);
	if (!info) {
		ret = -ENOMEM;
		goto err_release_regions;
	}
	pci_set_drvdata(pdev, info);
	par = info->par;

	info->fix = mdpy_fb_fix;
	info->fix.smem_start = pci_resource_start(pdev, 0);
	info->fix.smem_len = pci_resource_len(pdev, 0);
	info->fix.line_length = width * 4;

	info->var = mdpy_fb_var;
	info->var.xres = width;
	info->var.yres = height;
	info->var.xres_virtual = width;
	info->var.yres_virtual = height;

	info->screen_size = info->fix.smem_len;
	info->screen_base = ioremap(info->fix.smem_start,
				    info->screen_size);
	if (!info->screen_base) {
		pci_err(pdev, "ioremap(pcibar) failed\n");
		ret = -EIO;
		goto err_release_fb;
	}

	info->apertures = alloc_apertures(1);
	if (!info->apertures) {
		ret = -ENOMEM;
		goto err_unmap;
	}
	info->apertures->ranges[0].base = info->fix.smem_start;
	info->apertures->ranges[0].size = info->fix.smem_len;

	info->fbops = &mdpy_fb_ops;
	info->flags = FBINFO_DEFAULT;
	info->pseudo_palette = par->palette;

	ret = register_framebuffer(info);
	if (ret < 0) {
		pci_err(pdev, "mdpy-fb device register failed: %d\n", ret);
		goto err_unmap;
	}

	pci_info(pdev, "fb%d registered\n", info->node);
	return 0;

err_unmap:
	iounmap(info->screen_base);

err_release_fb:
	framebuffer_release(info);

err_release_regions:
	pci_release_regions(pdev);

	return ret;
}

static void mdpy_fb_remove(struct pci_dev *pdev)
{
	struct fb_info *info = pci_get_drvdata(pdev);

	unregister_framebuffer(info);
	framebuffer_release(info);
}

static struct pci_device_id mdpy_fb_pci_table[] = {
	{
		.vendor	   = MDPY_PCI_VENDOR_ID,
		.device	   = MDPY_PCI_DEVICE_ID,
		.subvendor = MDPY_PCI_SUBVENDOR_ID,
		.subdevice = MDPY_PCI_SUBDEVICE_ID,
	}, {
		/* end of list */
	}
};

static struct pci_driver mdpy_fb_pci_driver = {
	.name		= "mdpy-fb",
	.id_table	= mdpy_fb_pci_table,
	.probe		= mdpy_fb_probe,
	.remove		= mdpy_fb_remove,
};

static int __init mdpy_fb_init(void)
{
	int ret;

	ret = pci_register_driver(&mdpy_fb_pci_driver);
	if (ret)
		return ret;

	return 0;
}

module_init(mdpy_fb_init);

MODULE_DEVICE_TABLE(pci, mdpy_fb_pci_table);
MODULE_LICENSE("GPL v2");