[PATCH] add bochs dispi interface framebuffer driver
From: Gerd Hoffmann
Date: Wed Sep 04 2013 - 05:55:27 EST
This patchs adds a frame buffer driver for (virtual/emulated) vga cards
implementing the bochs dispi interface. Supported hardware are the
bochs vga card with vbe extension and the qemu standard vga.
The driver uses a fixed depth of 32bpp. Otherwise it supports the full
(but small) feature set of the bochs dispi interface: Resolution
switching and display panning. It is tweaked to maximize fbcon speed,
so you'll get the comfort of the framebuffer console in kvm guests
without performance penalty.
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
---
drivers/video/Kconfig | 18 ++
drivers/video/Makefile | 1 +
drivers/video/bochsfb.c | 460 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 479 insertions(+)
create mode 100644 drivers/video/bochsfb.c
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 4cf1e1d..3f0ead4 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -284,6 +284,24 @@ config FB_CIRRUS
Say N unless you have such a graphics board or plan to get one
before you next recompile the kernel.
+config FB_BOCHS
+ tristate "Bochs dispi interface support"
+ depends on FB && PCI
+ select FB_CFB_FILLRECT
+ select FB_CFB_COPYAREA
+ select FB_CFB_IMAGEBLIT
+ ---help---
+ This is the frame buffer driver for (virtual/emulated) vga
+ cards implementing the bochs dispi interface. Supported
+ hardware are the bochs vga card with vbe extension and the
+ qemu standard vga.
+
+ The driver handles the PCI variants only. It uses a fixed
+ depth of 32bpp, anything else doesn't make sense these days.
+
+ Say Y here if you plan to run the kernel in a virtual machine
+ emulated by bochs or qemu.
+
config FB_PM2
tristate "Permedia2 support"
depends on FB && ((AMIGA && BROKEN) || PCI)
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index e8bae8d..a946a36 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -103,6 +103,7 @@ obj-$(CONFIG_FB_GOLDFISH) += goldfishfb.o
obj-$(CONFIG_FB_68328) += 68328fb.o
obj-$(CONFIG_FB_GBE) += gbefb.o
obj-$(CONFIG_FB_CIRRUS) += cirrusfb.o
+obj-$(CONFIG_FB_BOCHS) += bochsfb.o
obj-$(CONFIG_FB_ASILIANT) += asiliantfb.o
obj-$(CONFIG_FB_PXA) += pxafb.o
obj-$(CONFIG_FB_PXA168) += pxa168fb.o
diff --git a/drivers/video/bochsfb.c b/drivers/video/bochsfb.c
new file mode 100644
index 0000000..b31472e
--- /dev/null
+++ b/drivers/video/bochsfb.c
@@ -0,0 +1,460 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/fb.h>
+#include <linux/pm.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/console.h>
+#include <asm/io.h>
+
+#define VBE_DISPI_IOPORT_INDEX 0x01CE
+#define VBE_DISPI_IOPORT_DATA 0x01CF
+
+#define VBE_DISPI_INDEX_ID 0x0
+#define VBE_DISPI_INDEX_XRES 0x1
+#define VBE_DISPI_INDEX_YRES 0x2
+#define VBE_DISPI_INDEX_BPP 0x3
+#define VBE_DISPI_INDEX_ENABLE 0x4
+#define VBE_DISPI_INDEX_BANK 0x5
+#define VBE_DISPI_INDEX_VIRT_WIDTH 0x6
+#define VBE_DISPI_INDEX_VIRT_HEIGHT 0x7
+#define VBE_DISPI_INDEX_X_OFFSET 0x8
+#define VBE_DISPI_INDEX_Y_OFFSET 0x9
+#define VBE_DISPI_INDEX_VIDEO_MEMORY_64K 0xa
+
+#define VBE_DISPI_ID0 0xB0C0
+#define VBE_DISPI_ID1 0xB0C1
+#define VBE_DISPI_ID2 0xB0C2
+#define VBE_DISPI_ID3 0xB0C3
+#define VBE_DISPI_ID4 0xB0C4
+#define VBE_DISPI_ID5 0xB0C5
+
+#define VBE_DISPI_DISABLED 0x00
+#define VBE_DISPI_ENABLED 0x01
+#define VBE_DISPI_GETCAPS 0x02
+#define VBE_DISPI_8BIT_DAC 0x20
+#define VBE_DISPI_LFB_ENABLED 0x40
+#define VBE_DISPI_NOCLEARMEM 0x80
+
+enum bochs_types {
+ BOCHS_QEMU_STDVGA,
+ BOCHS_UNKNOWN,
+};
+
+static const char *bochs_names[] = {
+ [ BOCHS_QEMU_STDVGA ] = "QEMU standard vga",
+ [ BOCHS_UNKNOWN ] = "unknown",
+};
+
+struct bochs_par {
+ void __iomem *mmio;
+ int ioports;
+};
+
+static struct fb_fix_screeninfo bochsfb_fix = {
+ .id = "bochsfb",
+ .type = FB_TYPE_PACKED_PIXELS,
+ .visual = FB_VISUAL_TRUECOLOR,
+ .accel = FB_ACCEL_NONE,
+ .xpanstep = 1,
+ .ypanstep = 1,
+};
+
+static struct fb_var_screeninfo bochsfb_var = {
+ .xres = 1024,
+ .yres = 768,
+ .bits_per_pixel = 32,
+#ifdef __BIG_ENDIAN
+ .transp = { .length = 8, .offset = 0 },
+ .red = { .length = 8, .offset = 8 },
+ .green = { .length = 8, .offset = 16 },
+ .blue = { .length = 8, .offset = 24 },
+#else
+ .transp = { .length = 8, .offset = 24 },
+ .red = { .length = 8, .offset = 16 },
+ .green = { .length = 8, .offset = 8 },
+ .blue = { .length = 8, .offset = 0 },
+#endif
+ .height = -1,
+ .width = -1,
+ .vmode = FB_VMODE_NONINTERLACED,
+ .pixclock = 10000,
+ .left_margin = 16,
+ .right_margin = 16,
+ .upper_margin = 16,
+ .lower_margin = 16,
+ .hsync_len = 8,
+ .vsync_len = 8,
+};
+
+static char *mode;
+module_param(mode, charp, 0);
+MODULE_PARM_DESC(mode, "Initial video mode, default is '1024x768'");
+
+static u16 bochs_read(struct fb_info *info, u16 reg)
+{
+ struct bochs_par *bochs = info->par;
+ u16 ret = 0;
+
+ if (bochs->mmio) {
+ int offset = 0x500 + (reg << 1);
+ ret = readw(bochs->mmio + offset);
+ } else {
+ outw(reg, VBE_DISPI_IOPORT_INDEX);
+ ret = inw(VBE_DISPI_IOPORT_DATA);
+ }
+ return ret;
+}
+
+static void bochs_write(struct fb_info *info, u16 reg, u16 val)
+{
+ struct bochs_par *bochs = info->par;
+
+ if (bochs->mmio) {
+ int offset = 0x500 + (reg << 1);
+ writew(val, bochs->mmio + offset);
+ } else {
+ outw(reg, VBE_DISPI_IOPORT_INDEX);
+ outw(val, VBE_DISPI_IOPORT_DATA);
+ }
+}
+
+static int bochsfb_check_var(struct fb_var_screeninfo *var,
+ struct fb_info *info)
+{
+ uint32_t x,y, xv,yv, pixels;
+
+ if (var->bits_per_pixel != 32 ||
+ var->xres > 65535 ||
+ var->xres_virtual > 65535 ||
+ (var->vmode & FB_VMODE_MASK) != FB_VMODE_NONINTERLACED)
+ return -EINVAL;
+
+ x = var->xres;
+ y = var->yres;
+ xv = var->xres_virtual;
+ yv = var->yres_virtual;
+ if (xv < x)
+ xv = x;
+ pixels = info->fix.smem_len * 8 / info->var.bits_per_pixel;
+ yv = pixels / xv;
+ if (y > yv)
+ return -EINVAL;
+
+ var->xres = x;
+ var->yres = y;
+ var->xres_virtual = xv;
+ var->yres_virtual = yv;
+ var->xoffset = 0;
+ var->yoffset = 0;
+
+ return 0;
+}
+
+static int bochsfb_set_par(struct fb_info *info)
+{
+ dev_dbg(info->dev, "set mode: real: %dx%d, virtual: %dx%d\n",
+ info->var.xres, info->var.yres,
+ info->var.xres_virtual, info->var.yres_virtual);
+
+ info->fix.line_length = info->var.xres * info->var.bits_per_pixel / 8;
+
+ bochs_write(info, VBE_DISPI_INDEX_BPP, info->var.bits_per_pixel);
+ bochs_write(info, VBE_DISPI_INDEX_XRES, info->var.xres);
+ bochs_write(info, VBE_DISPI_INDEX_YRES, info->var.yres);
+ bochs_write(info, VBE_DISPI_INDEX_BANK, 0);
+ bochs_write(info, VBE_DISPI_INDEX_VIRT_WIDTH, info->var.xres_virtual);
+ bochs_write(info, VBE_DISPI_INDEX_VIRT_HEIGHT, info->var.yres_virtual);
+ bochs_write(info, VBE_DISPI_INDEX_X_OFFSET, info->var.xoffset);
+ bochs_write(info, VBE_DISPI_INDEX_Y_OFFSET, info->var.yoffset);
+
+ bochs_write(info, VBE_DISPI_INDEX_ENABLE,
+ VBE_DISPI_ENABLED | VBE_DISPI_LFB_ENABLED);
+ return 0;
+}
+
+static int bochsfb_setcolreg(unsigned regno, unsigned red, unsigned green,
+ unsigned blue, unsigned transp,
+ struct fb_info *info)
+{
+ if (regno < 16 && info->var.bits_per_pixel == 32) {
+ red >>= 8;
+ green >>= 8;
+ blue >>= 8;
+ ((u32 *)(info->pseudo_palette))[regno] =
+ (red << info->var.red.offset) |
+ (green << info->var.green.offset) |
+ (blue << info->var.blue.offset);
+ }
+ return 0;
+}
+
+static int bochsfb_pan_display(struct fb_var_screeninfo *var,
+ struct fb_info *info)
+{
+ bochs_write(info, VBE_DISPI_INDEX_X_OFFSET, var->xoffset);
+ bochs_write(info, VBE_DISPI_INDEX_Y_OFFSET, var->yoffset);
+ return 0;
+}
+
+static struct fb_ops bochsfb_ops = {
+ .owner = THIS_MODULE,
+ .fb_check_var = bochsfb_check_var,
+ .fb_set_par = bochsfb_set_par,
+ .fb_setcolreg = bochsfb_setcolreg,
+ .fb_pan_display = bochsfb_pan_display,
+ .fb_fillrect = cfb_fillrect,
+ .fb_copyarea = cfb_copyarea,
+ .fb_imageblit = cfb_imageblit,
+};
+
+static int
+bochsfb_pci_init(struct pci_dev *dp, const struct pci_device_id *ent)
+{
+ struct fb_info *p;
+ unsigned long addr, size, mem, ioaddr, iosize;
+ struct bochs_par *bochs;
+ u16 id;
+ int rc = -ENODEV;
+
+ p = framebuffer_alloc(sizeof(struct bochs_par), &dp->dev);
+ if (p == NULL) {
+ dev_err(&dp->dev, "Cannot allocate framebuffer structure\n");
+ return -ENOMEM;
+ }
+ bochs = p->par;
+
+ if (pci_enable_device(dp) < 0) {
+ dev_err(&dp->dev, "Cannot enable PCI device\n");
+ goto err_out;
+ }
+
+ if ((ent->driver_data == BOCHS_QEMU_STDVGA) &&
+ (dp->resource[2].flags & IORESOURCE_MEM)) {
+ /* mmio bar with vga and bochs registers present */
+ if (pci_request_region(dp, 2, "bochsfb") != 0) {
+ dev_err(&dp->dev, "Cannot request mmio region\n");
+ rc = -EBUSY;
+ goto err_out;
+ }
+ ioaddr = pci_resource_start(dp, 2);
+ iosize = pci_resource_len(dp, 2);
+ bochs->mmio = ioremap(ioaddr, iosize);
+ if (bochs->mmio == NULL) {
+ dev_err(&dp->dev, "Cannot map mmio region\n");
+ rc = -ENOMEM;
+ goto err_out;
+ }
+ } else {
+ ioaddr = VBE_DISPI_IOPORT_INDEX;
+ iosize = 2;
+ if (!request_region(ioaddr, iosize, "bochsfb")) {
+ dev_err(&dp->dev, "Cannot request ioports\n");
+ rc = -EBUSY;
+ goto err_out;
+ }
+ bochs->ioports = 1;
+ }
+
+ id = bochs_read(p, VBE_DISPI_INDEX_ID);
+ mem = bochs_read(p, VBE_DISPI_INDEX_VIDEO_MEMORY_64K) * 64 * 1024;
+ if ((id & 0xfff0) != VBE_DISPI_ID0) {
+ dev_err(&dp->dev, "ID mismatch\n");
+ goto err_out;
+ }
+
+ if ((dp->resource[0].flags & IORESOURCE_MEM) == 0)
+ goto err_out;
+ addr = pci_resource_start(dp, 0);
+ size = pci_resource_len(dp, 0);
+ if (addr == 0)
+ goto err_out;
+ if (size != mem) {
+ dev_err(&dp->dev, "Size mismatch: pci=%ld, bochs=%ld\n", size, mem);
+ size = min(size, mem);
+ }
+
+ p->apertures = alloc_apertures(1);
+ if (!p->apertures) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+ p->apertures->ranges[0].base = addr;
+ p->apertures->ranges[0].size = size;
+ remove_conflicting_framebuffers(p->apertures, "bochsfb", false);
+
+ if (pci_request_region(dp, 0, "bochsfb") != 0) {
+ dev_err(&dp->dev, "Cannot request framebuffer\n");
+ rc = -EBUSY;
+ goto err_out;
+ }
+
+ p->screen_base = ioremap(addr, size);
+ if (p->screen_base == NULL) {
+ dev_err(&dp->dev, "Cannot map framebuffer\n");
+ rc = -ENOMEM;
+ goto err_out;
+ }
+ memset(p->screen_base, 0, size);
+
+ dev_info(&dp->dev,"Found bochs VGA, ID 0x%x, type \"%s\".\n",
+ id, bochs_names[ent->driver_data]);
+ dev_info(&dp->dev,"Framebuffer size %ld kB @ 0x%lx, %s @ 0x%lx.\n",
+ size / 1024, addr,
+ bochs->ioports ? "ioports" : "mmio",
+ ioaddr);
+
+ pci_set_drvdata(dp, p);
+ p->fbops = &bochsfb_ops;
+ p->flags = FBINFO_FLAG_DEFAULT
+ | FBINFO_READS_FAST
+ | FBINFO_HWACCEL_XPAN
+ | FBINFO_HWACCEL_YPAN;
+ p->pseudo_palette = kmalloc(sizeof(u32) * 16, GFP_KERNEL);
+ p->fix = bochsfb_fix;
+ p->fix.smem_start = addr;
+ p->fix.smem_len = size;
+
+ if (screen_info.orig_video_isVGA == VIDEO_TYPE_VLFB ||
+ screen_info.orig_video_isVGA == VIDEO_TYPE_EFI) {
+ dev_info(&dp->dev,"Picking up default res %dx%d from %s.\n",
+ screen_info.lfb_width, screen_info.lfb_height,
+ screen_info.orig_video_isVGA == VIDEO_TYPE_VLFB ?
+ "vesa" : "efi");
+ screen_info.orig_video_isVGA = 0;
+ bochsfb_var.xres = screen_info.lfb_width;
+ bochsfb_var.yres = screen_info.lfb_height;
+ }
+
+ p->var = bochsfb_var;
+ bochsfb_check_var(&p->var, p);
+ if (mode) {
+ dev_info(&dp->dev,"Looking up configured res \"%s\" in modedb.\n",
+ mode);
+ fb_find_mode(&p->var, p, mode, NULL, 0, NULL, 32);
+ }
+
+ if (register_framebuffer(p) < 0) {
+ dev_err(&dp->dev,"Framebuffer failed to register\n");
+ goto err_out;
+ }
+
+ dev_info(&dp->dev,"fb%d: bochs VGA frame buffer initialized.\n",
+ p->node);
+
+ return 0;
+
+err_out:
+ if (bochs->mmio)
+ iounmap(bochs->mmio);
+ if (bochs->ioports)
+ release_region(VBE_DISPI_IOPORT_INDEX, 2);
+ if (p->screen_base)
+ iounmap(p->screen_base);
+ pci_release_regions(dp);
+ framebuffer_release(p);
+ return rc;
+}
+
+static void bochsfb_remove(struct pci_dev *dp)
+{
+ struct fb_info *p = pci_get_drvdata(dp);
+ struct bochs_par *bochs = p->par;
+
+ if (p->screen_base == NULL)
+ return;
+ unregister_framebuffer(p);
+ if (bochs->mmio)
+ iounmap(bochs->mmio);
+ if (bochs->ioports)
+ release_region(VBE_DISPI_IOPORT_INDEX, 2);
+ if (p->screen_base)
+ iounmap(p->screen_base);
+ pci_release_regions(dp);
+ kfree(p->pseudo_palette);
+ framebuffer_release(p);
+}
+
+static struct pci_device_id bochsfb_pci_tbl[] = {
+ {
+ .vendor = 0x1234,
+ .device = 0x1111,
+ .subvendor = 0x1af4,
+ .subdevice = 0x1100,
+ .driver_data = BOCHS_QEMU_STDVGA,
+ },
+ {
+ .vendor = 0x1234,
+ .device = 0x1111,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .driver_data = BOCHS_UNKNOWN,
+ },
+ { /* end of list */ }
+};
+
+MODULE_DEVICE_TABLE(pci, bochsfb_pci_tbl);
+
+static struct pci_driver bochsfb_driver = {
+ .name = "bochsfb",
+ .id_table = bochsfb_pci_tbl,
+ .probe = bochsfb_pci_init,
+ .remove = bochsfb_remove,
+};
+
+#ifndef MODULE
+static int __init bochsfb_setup(char *options)
+{
+ char *this_opt;
+
+ if (!options || !*options)
+ return 0;
+
+ while ((this_opt = strsep(&options, ",")) != NULL) {
+ if (!*this_opt)
+ continue;
+ if (!strncmp(this_opt, "mode:", 5))
+ mode = this_opt + 5;
+ else
+ mode = this_opt;
+ }
+ return 0;
+}
+#endif
+
+int __init bochs_init(void)
+{
+#ifndef MODULE
+ char *option = NULL;
+
+ if (fb_get_options("bochsfb", &option))
+ return -ENODEV;
+ bochsfb_setup(option);
+#endif
+ return pci_register_driver(&bochsfb_driver);
+}
+
+module_init(bochs_init);
+
+static void __exit bochsfb_exit(void)
+{
+ pci_unregister_driver(&bochsfb_driver);
+}
+
+module_exit(bochsfb_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Gerd Hoffmann <kraxel@xxxxxxxxxx>");
+MODULE_DESCRIPTION("bochs dispi interface framebuffer driver");
--
1.8.3.1
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