diff options
Diffstat (limited to 'samples/vfio-mdev/mdpy-fb.c')
| -rw-r--r-- | samples/vfio-mdev/mdpy-fb.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/samples/vfio-mdev/mdpy-fb.c b/samples/vfio-mdev/mdpy-fb.c new file mode 100644 index 0000000000..4598bc28ac --- /dev/null +++ b/samples/vfio-mdev/mdpy-fb.c @@ -0,0 +1,232 @@ +// 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_DEFAULT_IOMEM_OPS, + .fb_destroy = mdpy_fb_destroy, + .fb_setcolreg = mdpy_fb_setcolreg, +}; + +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) + goto err_disable_dev; + + 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->fbops = &mdpy_fb_ops; + 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); + +err_disable_dev: + pci_disable_device(pdev); + + return ret; +} + +static void mdpy_fb_remove(struct pci_dev *pdev) +{ + struct fb_info *info = pci_get_drvdata(pdev); + + unregister_framebuffer(info); + iounmap(info->screen_base); + framebuffer_release(info); + pci_release_regions(pdev); + pci_disable_device(pdev); +} + +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"); |