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 | |
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 | |
83 | static void mdpy_fb_destroy(struct fb_info *info) |
84 | { |
85 | if (info->screen_base) |
86 | iounmap(addr: info->screen_base); |
87 | } |
88 | |
89 | static 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 | |
96 | static 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(dev: 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(dev: pdev, MDPY_FORMAT_OFFSET, val: &format); |
113 | pci_read_config_dword(dev: pdev, MDPY_WIDTH_OFFSET, val: &width); |
114 | pci_read_config_dword(dev: pdev, MDPY_HEIGHT_OFFSET, val: &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(size: sizeof(struct mdpy_fb_par), dev: &pdev->dev); |
135 | if (!info) { |
136 | ret = -ENOMEM; |
137 | goto err_release_regions; |
138 | } |
139 | pci_set_drvdata(pdev, data: 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(offset: info->fix.smem_start, |
155 | size: 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(fb_info: 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 | |
174 | err_unmap: |
175 | iounmap(addr: info->screen_base); |
176 | |
177 | err_release_fb: |
178 | framebuffer_release(info); |
179 | |
180 | err_release_regions: |
181 | pci_release_regions(pdev); |
182 | |
183 | err_disable_dev: |
184 | pci_disable_device(dev: pdev); |
185 | |
186 | return ret; |
187 | } |
188 | |
189 | static void mdpy_fb_remove(struct pci_dev *pdev) |
190 | { |
191 | struct fb_info *info = pci_get_drvdata(pdev); |
192 | |
193 | unregister_framebuffer(fb_info: info); |
194 | iounmap(addr: info->screen_base); |
195 | framebuffer_release(info); |
196 | pci_release_regions(pdev); |
197 | pci_disable_device(dev: pdev); |
198 | } |
199 | |
200 | static 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 | |
211 | static 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 | |
218 | static 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 | |
229 | module_init(mdpy_fb_init); |
230 | |
231 | MODULE_DEVICE_TABLE(pci, mdpy_fb_pci_table); |
232 | MODULE_LICENSE("GPL v2" ); |
233 | |