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 <kraxel@redhat.com>
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
28 static 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
35 static 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
54 struct mdpy_fb_par {
55 u32 palette[PSEUDO_PALETTE_SIZE];
56 };
57
mdpy_fb_setcolreg(u_int regno,u_int red,u_int green,u_int blue,u_int transp,struct fb_info * info)58 static 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
mdpy_fb_destroy(struct fb_info * info)83 static void mdpy_fb_destroy(struct fb_info *info)
84 {
85 if (info->screen_base)
86 iounmap(info->screen_base);
87 }
88
89 static const struct fb_ops mdpy_fb_ops = {
90 .owner = THIS_MODULE,
91 .fb_destroy = mdpy_fb_destroy,
92 .fb_setcolreg = mdpy_fb_setcolreg,
93 .fb_fillrect = cfb_fillrect,
94 .fb_copyarea = cfb_copyarea,
95 .fb_imageblit = cfb_imageblit,
96 };
97
mdpy_fb_probe(struct pci_dev * pdev,const struct pci_device_id * ent)98 static int mdpy_fb_probe(struct pci_dev *pdev,
99 const struct pci_device_id *ent)
100 {
101 struct fb_info *info;
102 struct mdpy_fb_par *par;
103 u32 format, width, height;
104 int ret;
105
106 ret = pci_enable_device(pdev);
107 if (ret < 0)
108 return ret;
109
110 ret = pci_request_regions(pdev, "mdpy-fb");
111 if (ret < 0)
112 return ret;
113
114 pci_read_config_dword(pdev, MDPY_FORMAT_OFFSET, &format);
115 pci_read_config_dword(pdev, MDPY_WIDTH_OFFSET, &width);
116 pci_read_config_dword(pdev, MDPY_HEIGHT_OFFSET, &height);
117 if (format != DRM_FORMAT_XRGB8888) {
118 pci_err(pdev, "format mismatch (0x%x != 0x%x)\n",
119 format, DRM_FORMAT_XRGB8888);
120 ret = -EINVAL;
121 goto err_release_regions;
122 }
123 if (width < 100 || width > 10000) {
124 pci_err(pdev, "width (%d) out of range\n", width);
125 ret = -EINVAL;
126 goto err_release_regions;
127 }
128 if (height < 100 || height > 10000) {
129 pci_err(pdev, "height (%d) out of range\n", height);
130 ret = -EINVAL;
131 goto err_release_regions;
132 }
133 pci_info(pdev, "mdpy found: %dx%d framebuffer\n",
134 width, height);
135
136 info = framebuffer_alloc(sizeof(struct mdpy_fb_par), &pdev->dev);
137 if (!info) {
138 ret = -ENOMEM;
139 goto err_release_regions;
140 }
141 pci_set_drvdata(pdev, info);
142 par = info->par;
143
144 info->fix = mdpy_fb_fix;
145 info->fix.smem_start = pci_resource_start(pdev, 0);
146 info->fix.smem_len = pci_resource_len(pdev, 0);
147 info->fix.line_length = width * 4;
148
149 info->var = mdpy_fb_var;
150 info->var.xres = width;
151 info->var.yres = height;
152 info->var.xres_virtual = width;
153 info->var.yres_virtual = height;
154
155 info->screen_size = info->fix.smem_len;
156 info->screen_base = ioremap(info->fix.smem_start,
157 info->screen_size);
158 if (!info->screen_base) {
159 pci_err(pdev, "ioremap(pcibar) failed\n");
160 ret = -EIO;
161 goto err_release_fb;
162 }
163
164 info->apertures = alloc_apertures(1);
165 if (!info->apertures) {
166 ret = -ENOMEM;
167 goto err_unmap;
168 }
169 info->apertures->ranges[0].base = info->fix.smem_start;
170 info->apertures->ranges[0].size = info->fix.smem_len;
171
172 info->fbops = &mdpy_fb_ops;
173 info->flags = FBINFO_DEFAULT;
174 info->pseudo_palette = par->palette;
175
176 ret = register_framebuffer(info);
177 if (ret < 0) {
178 pci_err(pdev, "mdpy-fb device register failed: %d\n", ret);
179 goto err_unmap;
180 }
181
182 pci_info(pdev, "fb%d registered\n", info->node);
183 return 0;
184
185 err_unmap:
186 iounmap(info->screen_base);
187
188 err_release_fb:
189 framebuffer_release(info);
190
191 err_release_regions:
192 pci_release_regions(pdev);
193
194 return ret;
195 }
196
mdpy_fb_remove(struct pci_dev * pdev)197 static void mdpy_fb_remove(struct pci_dev *pdev)
198 {
199 struct fb_info *info = pci_get_drvdata(pdev);
200
201 unregister_framebuffer(info);
202 framebuffer_release(info);
203 }
204
205 static struct pci_device_id mdpy_fb_pci_table[] = {
206 {
207 .vendor = MDPY_PCI_VENDOR_ID,
208 .device = MDPY_PCI_DEVICE_ID,
209 .subvendor = MDPY_PCI_SUBVENDOR_ID,
210 .subdevice = MDPY_PCI_SUBDEVICE_ID,
211 }, {
212 /* end of list */
213 }
214 };
215
216 static struct pci_driver mdpy_fb_pci_driver = {
217 .name = "mdpy-fb",
218 .id_table = mdpy_fb_pci_table,
219 .probe = mdpy_fb_probe,
220 .remove = mdpy_fb_remove,
221 };
222
mdpy_fb_init(void)223 static int __init mdpy_fb_init(void)
224 {
225 int ret;
226
227 ret = pci_register_driver(&mdpy_fb_pci_driver);
228 if (ret)
229 return ret;
230
231 return 0;
232 }
233
234 module_init(mdpy_fb_init);
235
236 MODULE_DEVICE_TABLE(pci, mdpy_fb_pci_table);
237 MODULE_LICENSE("GPL v2");
238