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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Framebuffer driver for mdpy (mediated virtual pci display device).
4 *
5 * See mdpy-defs.h for device specs
6 *
7 * (c) Gerd Hoffmann <[email protected]>
8 *
9 * Using some code snippets from simplefb and cirrusfb.
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms and conditions of the GNU General Public License,
13 * version 2, as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
18 * more details.
19 */
20#include <linux/errno.h>
21#include <linux/fb.h>
22#include <linux/io.h>
23#include <linux/pci.h>
24#include <linux/module.h>
25#include <drm/drm_fourcc.h>
26#include "mdpy-defs.h"
27
28static const struct fb_fix_screeninfo mdpy_fb_fix = {
29 .id = "mdpy-fb",
30 .type = FB_TYPE_PACKED_PIXELS,
31 .visual = FB_VISUAL_TRUECOLOR,
32 .accel = FB_ACCEL_NONE,
33};
34
35static const struct fb_var_screeninfo mdpy_fb_var = {
36 .height = -1,
37 .width = -1,
38 .activate = FB_ACTIVATE_NOW,
39 .vmode = FB_VMODE_NONINTERLACED,
40
41 .bits_per_pixel = 32,
42 .transp.offset = 24,
43 .red.offset = 16,
44 .green.offset = 8,
45 .blue.offset = 0,
46 .transp.length = 8,
47 .red.length = 8,
48 .green.length = 8,
49 .blue.length = 8,
50};
51
52#define PSEUDO_PALETTE_SIZE 16
53
54struct mdpy_fb_par {
55 u32 palette[PSEUDO_PALETTE_SIZE];
56};
57
58static int mdpy_fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
59 u_int transp, struct fb_info *info)
60{
61 u32 *pal = info->pseudo_palette;
62 u32 cr = red >> (16 - info->var.red.length);
63 u32 cg = green >> (16 - info->var.green.length);
64 u32 cb = blue >> (16 - info->var.blue.length);
65 u32 value, mask;
66
67 if (regno >= PSEUDO_PALETTE_SIZE)
68 return -EINVAL;
69
70 value = (cr << info->var.red.offset) |
71 (cg << info->var.green.offset) |
72 (cb << info->var.blue.offset);
73 if (info->var.transp.length > 0) {
74 mask = (1 << info->var.transp.length) - 1;
75 mask <<= info->var.transp.offset;
76 value |= mask;
77 }
78 pal[regno] = value;
79
80 return 0;
81}
82
83static void mdpy_fb_destroy(struct fb_info *info)
84{
85 if (info->screen_base)
86 iounmap(info->screen_base);
87}
88
89static const struct fb_ops mdpy_fb_ops = {
90 .owner = THIS_MODULE,
91 FB_DEFAULT_IOMEM_OPS,
92 .fb_destroy = mdpy_fb_destroy,
93 .fb_setcolreg = mdpy_fb_setcolreg,
94};
95
96static int mdpy_fb_probe(struct pci_dev *pdev,
97 const struct pci_device_id *ent)
98{
99 struct fb_info *info;
100 struct mdpy_fb_par *par;
101 u32 format, width, height;
102 int ret;
103
104 ret = pci_enable_device(pdev);
105 if (ret < 0)
106 return ret;
107
108 ret = pci_request_regions(pdev, "mdpy-fb");
109 if (ret < 0)
110 goto err_disable_dev;
111
112 pci_read_config_dword(pdev, MDPY_FORMAT_OFFSET, &format);
113 pci_read_config_dword(pdev, MDPY_WIDTH_OFFSET, &width);
114 pci_read_config_dword(pdev, MDPY_HEIGHT_OFFSET, &height);
115 if (format != DRM_FORMAT_XRGB8888) {
116 pci_err(pdev, "format mismatch (0x%x != 0x%x)\n",
117 format, DRM_FORMAT_XRGB8888);
118 ret = -EINVAL;
119 goto err_release_regions;
120 }
121 if (width < 100 || width > 10000) {
122 pci_err(pdev, "width (%d) out of range\n", width);
123 ret = -EINVAL;
124 goto err_release_regions;
125 }
126 if (height < 100 || height > 10000) {
127 pci_err(pdev, "height (%d) out of range\n", height);
128 ret = -EINVAL;
129 goto err_release_regions;
130 }
131 pci_info(pdev, "mdpy found: %dx%d framebuffer\n",
132 width, height);
133
134 info = framebuffer_alloc(sizeof(struct mdpy_fb_par), &pdev->dev);
135 if (!info) {
136 ret = -ENOMEM;
137 goto err_release_regions;
138 }
139 pci_set_drvdata(pdev, info);
140 par = info->par;
141
142 info->fix = mdpy_fb_fix;
143 info->fix.smem_start = pci_resource_start(pdev, 0);
144 info->fix.smem_len = pci_resource_len(pdev, 0);
145 info->fix.line_length = width * 4;
146
147 info->var = mdpy_fb_var;
148 info->var.xres = width;
149 info->var.yres = height;
150 info->var.xres_virtual = width;
151 info->var.yres_virtual = height;
152
153 info->screen_size = info->fix.smem_len;
154 info->screen_base = ioremap(info->fix.smem_start,
155 info->screen_size);
156 if (!info->screen_base) {
157 pci_err(pdev, "ioremap(pcibar) failed\n");
158 ret = -EIO;
159 goto err_release_fb;
160 }
161
162 info->fbops = &mdpy_fb_ops;
163 info->pseudo_palette = par->palette;
164
165 ret = register_framebuffer(info);
166 if (ret < 0) {
167 pci_err(pdev, "mdpy-fb device register failed: %d\n", ret);
168 goto err_unmap;
169 }
170
171 pci_info(pdev, "fb%d registered\n", info->node);
172 return 0;
173
174err_unmap:
175 iounmap(info->screen_base);
176
177err_release_fb:
178 framebuffer_release(info);
179
180err_release_regions:
181 pci_release_regions(pdev);
182
183err_disable_dev:
184 pci_disable_device(pdev);
185
186 return ret;
187}
188
189static void mdpy_fb_remove(struct pci_dev *pdev)
190{
191 struct fb_info *info = pci_get_drvdata(pdev);
192
193 unregister_framebuffer(info);
194 iounmap(info->screen_base);
195 framebuffer_release(info);
196 pci_release_regions(pdev);
197 pci_disable_device(pdev);
198}
199
200static struct pci_device_id mdpy_fb_pci_table[] = {
201 {
202 .vendor = MDPY_PCI_VENDOR_ID,
203 .device = MDPY_PCI_DEVICE_ID,
204 .subvendor = MDPY_PCI_SUBVENDOR_ID,
205 .subdevice = MDPY_PCI_SUBDEVICE_ID,
206 }, {
207 /* end of list */
208 }
209};
210
211static struct pci_driver mdpy_fb_pci_driver = {
212 .name = "mdpy-fb",
213 .id_table = mdpy_fb_pci_table,
214 .probe = mdpy_fb_probe,
215 .remove = mdpy_fb_remove,
216};
217
218static int __init mdpy_fb_init(void)
219{
220 int ret;
221
222 ret = pci_register_driver(&mdpy_fb_pci_driver);
223 if (ret)
224 return ret;
225
226 return 0;
227}
228
229module_init(mdpy_fb_init);
230
231MODULE_DEVICE_TABLE(pci, mdpy_fb_pci_table);
232MODULE_DESCRIPTION("Framebuffer driver for mdpy (mediated virtual pci display device)");
233MODULE_LICENSE("GPL v2");