vesafb.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * framebuffer driver for VBE 2.0 compliant graphic boards
  4 *
  5 * switching to graphics mode happens at boot time (while
  6 * running in real mode, see arch/i386/boot/video.S).
  7 *
  8 * (c) 1998 Gerd Knorr <kraxel@goldbach.in-berlin.de>
  9 *
 10 */
 11
 12#include <linux/aperture.h>
 13#include <linux/module.h>
 14#include <linux/kernel.h>
 15#include <linux/errno.h>
 16#include <linux/string.h>
 17#include <linux/mm.h>
 18#include <linux/delay.h>
 19#include <linux/fb.h>
 20#include <linux/ioport.h>
 21#include <linux/init.h>
 22#include <linux/platform_device.h>
 23#include <linux/screen_info.h>
 24#include <linux/io.h>
 25
 26#include <video/vga.h>
 27
 28#define dac_reg	(0x3c8)
 29#define dac_val	(0x3c9)
 30
 31/* --------------------------------------------------------------------- */
 32
 33struct vesafb_par {
 34	u32 pseudo_palette[256];
 35	resource_size_t base;
 36	resource_size_t size;
 37	int wc_cookie;
 38	struct resource *region;
 39};
 40
 41static struct fb_var_screeninfo vesafb_defined = {
 42	.activate	= FB_ACTIVATE_NOW,
 43	.height		= -1,
 44	.width		= -1,
 45	.right_margin	= 32,
 46	.upper_margin	= 16,
 47	.lower_margin	= 4,
 48	.vsync_len	= 4,
 49	.vmode		= FB_VMODE_NONINTERLACED,
 50};
 51
 52static struct fb_fix_screeninfo vesafb_fix = {
 53	.id	= "VESA VGA",
 54	.type	= FB_TYPE_PACKED_PIXELS,
 55	.accel	= FB_ACCEL_NONE,
 56};
 57
 58static int   inverse    __read_mostly;
 59static int   mtrr       __read_mostly;		/* disable mtrr */
 60static int   vram_remap;			/* Set amount of memory to be used */
 61static int   vram_total;			/* Set total amount of memory */
 62static int   pmi_setpal __read_mostly = 1;	/* pmi for palette changes ??? */
 63static int   ypan       __read_mostly;		/* 0..nothing, 1..ypan, 2..ywrap */
 64static void  (*pmi_start)(void) __read_mostly;
 65static void  (*pmi_pal)  (void) __read_mostly;
 66static int   depth      __read_mostly;
 67static int   vga_compat __read_mostly;
 68/* --------------------------------------------------------------------- */
 69
 70static int vesafb_pan_display(struct fb_var_screeninfo *var,
 71                              struct fb_info *info)
 72{
 73#ifdef __i386__
 74	int offset;
 75
 76	offset = (var->yoffset * info->fix.line_length + var->xoffset) / 4;
 77
 78        __asm__ __volatile__(
 79                "call *(%%edi)"
 80                : /* no return value */
 81                : "a" (0x4f07),         /* EAX */
 82                  "b" (0),              /* EBX */
 83                  "c" (offset),         /* ECX */
 84                  "d" (offset >> 16),   /* EDX */
 85                  "D" (&pmi_start));    /* EDI */
 86#endif
 87	return 0;
 88}
 89
 90static int vesa_setpalette(int regno, unsigned red, unsigned green,
 91			    unsigned blue)
 92{
 93	int shift = 16 - depth;
 94	int err = -EINVAL;
 95
 96/*
 97 * Try VGA registers first...
 98 */
 99	if (vga_compat) {
100		outb_p(regno,       dac_reg);
101		outb_p(red   >> shift, dac_val);
102		outb_p(green >> shift, dac_val);
103		outb_p(blue  >> shift, dac_val);
104		err = 0;
105	}
106
107#ifdef __i386__
108/*
109 * Fallback to the PMI....
110 */
111	if (err && pmi_setpal) {
112		struct { u_char blue, green, red, pad; } entry;
113
114		entry.red   = red   >> shift;
115		entry.green = green >> shift;
116		entry.blue  = blue  >> shift;
117		entry.pad   = 0;
118	        __asm__ __volatile__(
119                "call *(%%esi)"
120                : /* no return value */
121                : "a" (0x4f09),         /* EAX */
122                  "b" (0),              /* EBX */
123                  "c" (1),              /* ECX */
124                  "d" (regno),          /* EDX */
125                  "D" (&entry),         /* EDI */
126                  "S" (&pmi_pal));      /* ESI */
127		err = 0;
128	}
129#endif
130
131	return err;
132}
133
134static int vesafb_setcolreg(unsigned regno, unsigned red, unsigned green,
135			    unsigned blue, unsigned transp,
136			    struct fb_info *info)
137{
138	int err = 0;
139
140	/*
141	 *  Set a single color register. The values supplied are
142	 *  already rounded down to the hardware's capabilities
143	 *  (according to the entries in the `var' structure). Return
144	 *  != 0 for invalid regno.
145	 */
146
147	if (regno >= info->cmap.len)
148		return 1;
149
150	if (info->var.bits_per_pixel == 8)
151		err = vesa_setpalette(regno,red,green,blue);
152	else if (regno < 16) {
153		switch (info->var.bits_per_pixel) {
154		case 16:
155			if (info->var.red.offset == 10) {
156				/* 1:5:5:5 */
157				((u32*) (info->pseudo_palette))[regno] =
158					((red   & 0xf800) >>  1) |
159					((green & 0xf800) >>  6) |
160					((blue  & 0xf800) >> 11);
161			} else {
162				/* 0:5:6:5 */
163				((u32*) (info->pseudo_palette))[regno] =
164					((red   & 0xf800)      ) |
165					((green & 0xfc00) >>  5) |
166					((blue  & 0xf800) >> 11);
167			}
168			break;
169		case 24:
170		case 32:
171			red   >>= 8;
172			green >>= 8;
173			blue  >>= 8;
174			((u32 *)(info->pseudo_palette))[regno] =
175				(red   << info->var.red.offset)   |
176				(green << info->var.green.offset) |
177				(blue  << info->var.blue.offset);
178			break;
179		}
180	}
181
182	return err;
183}
184
185/*
186 * fb_ops.fb_destroy is called by the last put_fb_info() call at the end
187 * of unregister_framebuffer() or fb_release(). Do any cleanup here.
188 */
189static void vesafb_destroy(struct fb_info *info)
190{
191	struct vesafb_par *par = info->par;
192
193	fb_dealloc_cmap(&info->cmap);
194	arch_phys_wc_del(par->wc_cookie);
195	if (info->screen_base)
196		iounmap(info->screen_base);
197	release_mem_region(par->base, par->size);
198
199	framebuffer_release(info);
200}
201
202static struct fb_ops vesafb_ops = {
203	.owner		= THIS_MODULE,
204	FB_DEFAULT_IOMEM_OPS,
205	.fb_destroy     = vesafb_destroy,
206	.fb_setcolreg	= vesafb_setcolreg,
207	.fb_pan_display	= vesafb_pan_display,
208};
209
210static int vesafb_setup(char *options)
211{
212	char *this_opt;
213
214	if (!options || !*options)
215		return 0;
216
217	while ((this_opt = strsep(&options, ",")) != NULL) {
218		if (!*this_opt) continue;
219
220		if (! strcmp(this_opt, "inverse"))
221			inverse=1;
222		else if (! strcmp(this_opt, "redraw"))
223			ypan=0;
224		else if (! strcmp(this_opt, "ypan"))
225			ypan=1;
226		else if (! strcmp(this_opt, "ywrap"))
227			ypan=2;
228		else if (! strcmp(this_opt, "vgapal"))
229			pmi_setpal=0;
230		else if (! strcmp(this_opt, "pmipal"))
231			pmi_setpal=1;
232		else if (! strncmp(this_opt, "mtrr:", 5))
233			mtrr = simple_strtoul(this_opt+5, NULL, 0);
234		else if (! strcmp(this_opt, "nomtrr"))
235			mtrr=0;
236		else if (! strncmp(this_opt, "vtotal:", 7))
237			vram_total = simple_strtoul(this_opt+7, NULL, 0);
238		else if (! strncmp(this_opt, "vremap:", 7))
239			vram_remap = simple_strtoul(this_opt+7, NULL, 0);
240	}
241	return 0;
242}
243
244static int vesafb_probe(struct platform_device *dev)
245{
246	struct screen_info *si;
247	struct fb_info *info;
248	struct vesafb_par *par;
249	int i, err;
250	unsigned int size_vmode;
251	unsigned int size_remap;
252	unsigned int size_total;
253	char *option = NULL;
254
255	/*
256	 * If we fail probing the device, the kernel might try a different
257	 * driver. We get a copy of the attached screen_info, so that we can
258	 * modify its values without affecting later drivers.
259	 */
260	si = dev_get_platdata(&dev->dev);
261	if (!si)
262		return -ENODEV;
263	si = devm_kmemdup(&dev->dev, si, sizeof(*si), GFP_KERNEL);
264	if (!si)
265		return -ENOMEM;
266
267	/* ignore error return of fb_get_options */
268	fb_get_options("vesafb", &option);
269	vesafb_setup(option);
270
271	if (si->orig_video_isVGA != VIDEO_TYPE_VLFB)
272		return -ENODEV;
273
274	vga_compat = !__screen_info_vbe_mode_nonvga(si);
275	vesafb_fix.smem_start = si->lfb_base;
276	vesafb_defined.bits_per_pixel = si->lfb_depth;
277	if (15 == vesafb_defined.bits_per_pixel)
278		vesafb_defined.bits_per_pixel = 16;
279	vesafb_defined.xres = si->lfb_width;
280	vesafb_defined.yres = si->lfb_height;
281	vesafb_fix.line_length = si->lfb_linelength;
282	vesafb_fix.visual   = (vesafb_defined.bits_per_pixel == 8) ?
283		FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;
284
285	/*   size_vmode -- that is the amount of memory needed for the
286	 *                 used video mode, i.e. the minimum amount of
287	 *                 memory we need. */
288	size_vmode = vesafb_defined.yres * vesafb_fix.line_length;
289
290	/*   size_total -- all video memory we have. Used for mtrr
291	 *                 entries, resource allocation and bounds
292	 *                 checking. */
293	size_total = si->lfb_size * 65536;
294	if (vram_total)
295		size_total = vram_total * 1024 * 1024;
296	if (size_total < size_vmode)
297		size_total = size_vmode;
298
299	/*   size_remap -- the amount of video memory we are going to
300	 *                 use for vesafb.  With modern cards it is no
301	 *                 option to simply use size_total as that
302	 *                 wastes plenty of kernel address space. */
303	size_remap  = size_vmode * 2;
304	if (vram_remap)
305		size_remap = vram_remap * 1024 * 1024;
306	if (size_remap < size_vmode)
307		size_remap = size_vmode;
308	if (size_remap > size_total)
309		size_remap = size_total;
310	vesafb_fix.smem_len = size_remap;
311
312#ifndef __i386__
313	si->vesapm_seg = 0;
314#endif
315
316	if (!request_mem_region(vesafb_fix.smem_start, size_total, "vesafb")) {
317		dev_warn(&dev->dev,
318		       "cannot reserve video memory at 0x%lx\n",
319			vesafb_fix.smem_start);
320		/* We cannot make this fatal. Sometimes this comes from magic
321		   spaces our resource handlers simply don't know about */
322	}
323
324	info = framebuffer_alloc(sizeof(struct vesafb_par), &dev->dev);
325	if (!info) {
326		release_mem_region(vesafb_fix.smem_start, size_total);
327		return -ENOMEM;
328	}
329	platform_set_drvdata(dev, info);
330	par = info->par;
331	info->pseudo_palette = par->pseudo_palette;
332
333	par->base = si->lfb_base;
334	par->size = size_total;
335
336	dev_info(&dev->dev, "mode is %dx%dx%d, linelength=%d, pages=%d\n",
337	       vesafb_defined.xres, vesafb_defined.yres, vesafb_defined.bits_per_pixel,
338	       vesafb_fix.line_length, si->pages);
339
340	if (si->vesapm_seg) {
341		dev_info(&dev->dev, "protected mode interface info at %04x:%04x\n",
342		       si->vesapm_seg, si->vesapm_off);
343	}
344
345	if (si->vesapm_seg < 0xc000)
346		ypan = pmi_setpal = 0; /* not available or some DOS TSR ... */
347
348	if (ypan || pmi_setpal) {
349		unsigned long pmi_phys;
350		unsigned short *pmi_base;
351		pmi_phys  = ((unsigned long)si->vesapm_seg << 4) + si->vesapm_off;
352		pmi_base  = (unsigned short *)phys_to_virt(pmi_phys);
353		pmi_start = (void*)((char*)pmi_base + pmi_base[1]);
354		pmi_pal   = (void*)((char*)pmi_base + pmi_base[2]);
355		dev_info(&dev->dev, "pmi: set display start = %p, set palette = %p\n",
356			 pmi_start, pmi_pal);
357		if (pmi_base[3]) {
358			dev_info(&dev->dev, "pmi: ports = ");
359			for (i = pmi_base[3]/2; pmi_base[i] != 0xffff; i++)
360				printk("%x ", pmi_base[i]);
361			printk("\n");
362			if (pmi_base[i] != 0xffff) {
363				/*
364				 * memory areas not supported (yet?)
365				 *
366				 * Rules are: we have to set up a descriptor for the requested
367				 * memory area and pass it in the ES register to the BIOS function.
368				 */
369				dev_info(&dev->dev, "can't handle memory requests, pmi disabled\n");
370				ypan = pmi_setpal = 0;
371			}
372		}
373	}
374
375	if (vesafb_defined.bits_per_pixel == 8 && !pmi_setpal && !vga_compat) {
376		dev_warn(&dev->dev, "hardware palette is unchangeable,\n"
377		                    "        colors may be incorrect\n");
378		vesafb_fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
379	}
380
381	vesafb_defined.xres_virtual = vesafb_defined.xres;
382	vesafb_defined.yres_virtual = vesafb_fix.smem_len / vesafb_fix.line_length;
383	if (ypan && vesafb_defined.yres_virtual > vesafb_defined.yres) {
384		dev_info(&dev->dev, "scrolling: %s using protected mode interface, yres_virtual=%d\n",
385		       (ypan > 1) ? "ywrap" : "ypan",vesafb_defined.yres_virtual);
386	} else {
387		dev_info(&dev->dev, "scrolling: redraw\n");
388		vesafb_defined.yres_virtual = vesafb_defined.yres;
389		ypan = 0;
390	}
391
392	/* some dummy values for timing to make fbset happy */
393	vesafb_defined.pixclock     = 10000000 / vesafb_defined.xres * 1000 / vesafb_defined.yres;
394	vesafb_defined.left_margin  = (vesafb_defined.xres / 8) & 0xf8;
395	vesafb_defined.hsync_len    = (vesafb_defined.xres / 8) & 0xf8;
396
397	vesafb_defined.red.offset    = si->red_pos;
398	vesafb_defined.red.length    = si->red_size;
399	vesafb_defined.green.offset  = si->green_pos;
400	vesafb_defined.green.length  = si->green_size;
401	vesafb_defined.blue.offset   = si->blue_pos;
402	vesafb_defined.blue.length   = si->blue_size;
403	vesafb_defined.transp.offset = si->rsvd_pos;
404	vesafb_defined.transp.length = si->rsvd_size;
405
406	if (vesafb_defined.bits_per_pixel <= 8) {
407		depth = vesafb_defined.green.length;
408		vesafb_defined.red.length =
409		vesafb_defined.green.length =
410		vesafb_defined.blue.length =
411		vesafb_defined.bits_per_pixel;
412	}
413
414	dev_info(&dev->dev, "%s: "
415	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
416	       (vesafb_defined.bits_per_pixel > 8) ?
417	       "Truecolor" : (vga_compat || pmi_setpal) ?
418	       "Pseudocolor" : "Static Pseudocolor",
419	       si->rsvd_size,
420	       si->red_size,
421	       si->green_size,
422	       si->blue_size,
423	       si->rsvd_pos,
424	       si->red_pos,
425	       si->green_pos,
426	       si->blue_pos);
427
428	vesafb_fix.ypanstep  = ypan     ? 1 : 0;
429	vesafb_fix.ywrapstep = (ypan>1) ? 1 : 0;
430
431	/* request failure does not faze us, as vgacon probably has this
432	 * region already (FIXME) */
433	par->region = request_region(0x3c0, 32, "vesafb");
434
435	if (mtrr == 3) {
436		unsigned int temp_size = size_total;
437
438		/* Find the largest power-of-two */
439		temp_size = roundup_pow_of_two(temp_size);
440
441		/* Try and find a power of two to add */
442		do {
443			par->wc_cookie =
444				arch_phys_wc_add(vesafb_fix.smem_start,
445						 temp_size);
446			temp_size >>= 1;
447		} while (temp_size >= PAGE_SIZE && par->wc_cookie < 0);
448
449		info->screen_base = ioremap_wc(vesafb_fix.smem_start, vesafb_fix.smem_len);
450	} else {
451		if (mtrr && mtrr != 3)
452			WARN_ONCE(1, "Only MTRR_TYPE_WRCOMB (3) make sense\n");
453		info->screen_base = ioremap(vesafb_fix.smem_start, vesafb_fix.smem_len);
454	}
455
456	if (!info->screen_base) {
457		dev_err(&dev->dev,
458		       "abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
459			vesafb_fix.smem_len, vesafb_fix.smem_start);
460		err = -EIO;
461		goto err_release_region;
462	}
463
464	dev_info(&dev->dev, "framebuffer at 0x%lx, mapped to 0x%p, "
465	       "using %dk, total %dk\n",
466	       vesafb_fix.smem_start, info->screen_base,
467	       size_remap/1024, size_total/1024);
468
469	if (!ypan)
470		vesafb_ops.fb_pan_display = NULL;
471
472	info->fbops = &vesafb_ops;
473	info->var = vesafb_defined;
474	info->fix = vesafb_fix;
475	info->flags = (ypan ? FBINFO_HWACCEL_YPAN : 0);
476
477	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
478		err = -ENOMEM;
479		goto err_release_region;
480	}
481	err = devm_aperture_acquire_for_platform_device(dev, par->base, par->size);
482	if (err)
483		goto err_fb_dealloc_cmap;
484	if (register_framebuffer(info)<0) {
485		err = -EINVAL;
486		goto err_fb_dealloc_cmap;
487	}
488	fb_info(info, "%s frame buffer device\n", info->fix.id);
489	return 0;
490err_fb_dealloc_cmap:
491	fb_dealloc_cmap(&info->cmap);
492err_release_region:
493	arch_phys_wc_del(par->wc_cookie);
494	if (info->screen_base)
495		iounmap(info->screen_base);
496	if (par->region)
497		release_region(0x3c0, 32);
498	framebuffer_release(info);
499	release_mem_region(vesafb_fix.smem_start, size_total);
500	return err;
501}
502
503static void vesafb_remove(struct platform_device *pdev)
504{
505	struct fb_info *info = platform_get_drvdata(pdev);
506
507	if (((struct vesafb_par *)(info->par))->region)
508		release_region(0x3c0, 32);
509
510	/* vesafb_destroy takes care of info cleanup */
511	unregister_framebuffer(info);
512}
513
514static struct platform_driver vesafb_driver = {
515	.driver = {
516		.name = "vesa-framebuffer",
517	},
518	.probe = vesafb_probe,
519	.remove = vesafb_remove,
520};
521
522module_platform_driver(vesafb_driver);
523MODULE_LICENSE("GPL");