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(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(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; 173 174 err_unmap: 175 iounmap(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(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(info); 194 iounmap(info->screen_base); 195 framebuffer_release(info); 196 pci_release_regions(pdev); 197 pci_disable_device(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