xref: /openbmc/linux/drivers/video/fbdev/offb.c (revision ca55b2fe)
1 /*
2  *  linux/drivers/video/offb.c -- Open Firmware based frame buffer device
3  *
4  *	Copyright (C) 1997 Geert Uytterhoeven
5  *
6  *  This driver is partly based on the PowerMac console driver:
7  *
8  *	Copyright (C) 1996 Paul Mackerras
9  *
10  *  This file is subject to the terms and conditions of the GNU General Public
11  *  License. See the file COPYING in the main directory of this archive for
12  *  more details.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/string.h>
19 #include <linux/mm.h>
20 #include <linux/vmalloc.h>
21 #include <linux/delay.h>
22 #include <linux/of.h>
23 #include <linux/of_address.h>
24 #include <linux/interrupt.h>
25 #include <linux/fb.h>
26 #include <linux/init.h>
27 #include <linux/ioport.h>
28 #include <linux/pci.h>
29 #include <asm/io.h>
30 
31 #ifdef CONFIG_PPC64
32 #include <asm/pci-bridge.h>
33 #endif
34 
35 #ifdef CONFIG_PPC32
36 #include <asm/bootx.h>
37 #endif
38 
39 #include "macmodes.h"
40 
41 /* Supported palette hacks */
42 enum {
43 	cmap_unknown,
44 	cmap_simple,		/* ATI Mach64 */
45 	cmap_r128,		/* ATI Rage128 */
46 	cmap_M3A,		/* ATI Rage Mobility M3 Head A */
47 	cmap_M3B,		/* ATI Rage Mobility M3 Head B */
48 	cmap_radeon,		/* ATI Radeon */
49 	cmap_gxt2000,		/* IBM GXT2000 */
50 	cmap_avivo,		/* ATI R5xx */
51 	cmap_qemu,		/* qemu vga */
52 };
53 
54 struct offb_par {
55 	volatile void __iomem *cmap_adr;
56 	volatile void __iomem *cmap_data;
57 	int cmap_type;
58 	int blanked;
59 };
60 
61 struct offb_par default_par;
62 
63 #ifdef CONFIG_PPC32
64 extern boot_infos_t *boot_infos;
65 #endif
66 
67 /* Definitions used by the Avivo palette hack */
68 #define AVIVO_DC_LUT_RW_SELECT                  0x6480
69 #define AVIVO_DC_LUT_RW_MODE                    0x6484
70 #define AVIVO_DC_LUT_RW_INDEX                   0x6488
71 #define AVIVO_DC_LUT_SEQ_COLOR                  0x648c
72 #define AVIVO_DC_LUT_PWL_DATA                   0x6490
73 #define AVIVO_DC_LUT_30_COLOR                   0x6494
74 #define AVIVO_DC_LUT_READ_PIPE_SELECT           0x6498
75 #define AVIVO_DC_LUT_WRITE_EN_MASK              0x649c
76 #define AVIVO_DC_LUT_AUTOFILL                   0x64a0
77 
78 #define AVIVO_DC_LUTA_CONTROL                   0x64c0
79 #define AVIVO_DC_LUTA_BLACK_OFFSET_BLUE         0x64c4
80 #define AVIVO_DC_LUTA_BLACK_OFFSET_GREEN        0x64c8
81 #define AVIVO_DC_LUTA_BLACK_OFFSET_RED          0x64cc
82 #define AVIVO_DC_LUTA_WHITE_OFFSET_BLUE         0x64d0
83 #define AVIVO_DC_LUTA_WHITE_OFFSET_GREEN        0x64d4
84 #define AVIVO_DC_LUTA_WHITE_OFFSET_RED          0x64d8
85 
86 #define AVIVO_DC_LUTB_CONTROL                   0x6cc0
87 #define AVIVO_DC_LUTB_BLACK_OFFSET_BLUE         0x6cc4
88 #define AVIVO_DC_LUTB_BLACK_OFFSET_GREEN        0x6cc8
89 #define AVIVO_DC_LUTB_BLACK_OFFSET_RED          0x6ccc
90 #define AVIVO_DC_LUTB_WHITE_OFFSET_BLUE         0x6cd0
91 #define AVIVO_DC_LUTB_WHITE_OFFSET_GREEN        0x6cd4
92 #define AVIVO_DC_LUTB_WHITE_OFFSET_RED          0x6cd8
93 
94     /*
95      *  Set a single color register. The values supplied are already
96      *  rounded down to the hardware's capabilities (according to the
97      *  entries in the var structure). Return != 0 for invalid regno.
98      */
99 
100 static int offb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
101 			  u_int transp, struct fb_info *info)
102 {
103 	struct offb_par *par = (struct offb_par *) info->par;
104 
105 	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
106 		u32 *pal = info->pseudo_palette;
107 		u32 cr = red >> (16 - info->var.red.length);
108 		u32 cg = green >> (16 - info->var.green.length);
109 		u32 cb = blue >> (16 - info->var.blue.length);
110 		u32 value;
111 
112 		if (regno >= 16)
113 			return -EINVAL;
114 
115 		value = (cr << info->var.red.offset) |
116 			(cg << info->var.green.offset) |
117 			(cb << info->var.blue.offset);
118 		if (info->var.transp.length > 0) {
119 			u32 mask = (1 << info->var.transp.length) - 1;
120 			mask <<= info->var.transp.offset;
121 			value |= mask;
122 		}
123 		pal[regno] = value;
124 		return 0;
125 	}
126 
127 	if (regno > 255)
128 		return -EINVAL;
129 
130 	red >>= 8;
131 	green >>= 8;
132 	blue >>= 8;
133 
134 	if (!par->cmap_adr)
135 		return 0;
136 
137 	switch (par->cmap_type) {
138 	case cmap_simple:
139 		writeb(regno, par->cmap_adr);
140 		writeb(red, par->cmap_data);
141 		writeb(green, par->cmap_data);
142 		writeb(blue, par->cmap_data);
143 		break;
144 	case cmap_M3A:
145 		/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
146 		out_le32(par->cmap_adr + 0x58,
147 			 in_le32(par->cmap_adr + 0x58) & ~0x20);
148 	case cmap_r128:
149 		/* Set palette index & data */
150 		out_8(par->cmap_adr + 0xb0, regno);
151 		out_le32(par->cmap_adr + 0xb4,
152 			 (red << 16 | green << 8 | blue));
153 		break;
154 	case cmap_M3B:
155 		/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
156 		out_le32(par->cmap_adr + 0x58,
157 			 in_le32(par->cmap_adr + 0x58) | 0x20);
158 		/* Set palette index & data */
159 		out_8(par->cmap_adr + 0xb0, regno);
160 		out_le32(par->cmap_adr + 0xb4, (red << 16 | green << 8 | blue));
161 		break;
162 	case cmap_radeon:
163 		/* Set palette index & data (could be smarter) */
164 		out_8(par->cmap_adr + 0xb0, regno);
165 		out_le32(par->cmap_adr + 0xb4, (red << 16 | green << 8 | blue));
166 		break;
167 	case cmap_gxt2000:
168 		out_le32(((unsigned __iomem *) par->cmap_adr) + regno,
169 			 (red << 16 | green << 8 | blue));
170 		break;
171 	case cmap_avivo:
172 		/* Write to both LUTs for now */
173 		writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
174 		writeb(regno, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
175 		writel(((red) << 22) | ((green) << 12) | ((blue) << 2),
176 		       par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
177 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
178 		writeb(regno, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
179 		writel(((red) << 22) | ((green) << 12) | ((blue) << 2),
180 		       par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
181 		break;
182 	}
183 
184 	return 0;
185 }
186 
187     /*
188      *  Blank the display.
189      */
190 
191 static int offb_blank(int blank, struct fb_info *info)
192 {
193 	struct offb_par *par = (struct offb_par *) info->par;
194 	int i, j;
195 
196 	if (!par->cmap_adr)
197 		return 0;
198 
199 	if (!par->blanked)
200 		if (!blank)
201 			return 0;
202 
203 	par->blanked = blank;
204 
205 	if (blank)
206 		for (i = 0; i < 256; i++) {
207 			switch (par->cmap_type) {
208 			case cmap_simple:
209 				writeb(i, par->cmap_adr);
210 				for (j = 0; j < 3; j++)
211 					writeb(0, par->cmap_data);
212 				break;
213 			case cmap_M3A:
214 				/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
215 				out_le32(par->cmap_adr + 0x58,
216 					 in_le32(par->cmap_adr + 0x58) & ~0x20);
217 			case cmap_r128:
218 				/* Set palette index & data */
219 				out_8(par->cmap_adr + 0xb0, i);
220 				out_le32(par->cmap_adr + 0xb4, 0);
221 				break;
222 			case cmap_M3B:
223 				/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
224 				out_le32(par->cmap_adr + 0x58,
225 					 in_le32(par->cmap_adr + 0x58) | 0x20);
226 				/* Set palette index & data */
227 				out_8(par->cmap_adr + 0xb0, i);
228 				out_le32(par->cmap_adr + 0xb4, 0);
229 				break;
230 			case cmap_radeon:
231 				out_8(par->cmap_adr + 0xb0, i);
232 				out_le32(par->cmap_adr + 0xb4, 0);
233 				break;
234 			case cmap_gxt2000:
235 				out_le32(((unsigned __iomem *) par->cmap_adr) + i,
236 					 0);
237 				break;
238 			case cmap_avivo:
239 				writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
240 				writeb(i, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
241 				writel(0, par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
242 				writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
243 				writeb(i, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
244 				writel(0, par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
245 				break;
246 			}
247 	} else
248 		fb_set_cmap(&info->cmap, info);
249 	return 0;
250 }
251 
252 static int offb_set_par(struct fb_info *info)
253 {
254 	struct offb_par *par = (struct offb_par *) info->par;
255 
256 	/* On avivo, initialize palette control */
257 	if (par->cmap_type == cmap_avivo) {
258 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_CONTROL);
259 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_BLUE);
260 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_GREEN);
261 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_RED);
262 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_BLUE);
263 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_GREEN);
264 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_RED);
265 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_CONTROL);
266 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_BLUE);
267 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_GREEN);
268 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_RED);
269 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_BLUE);
270 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_GREEN);
271 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_RED);
272 		writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
273 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_MODE);
274 		writel(0x0000003f, par->cmap_adr + AVIVO_DC_LUT_WRITE_EN_MASK);
275 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
276 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_MODE);
277 		writel(0x0000003f, par->cmap_adr + AVIVO_DC_LUT_WRITE_EN_MASK);
278 	}
279 	return 0;
280 }
281 
282 static void offb_destroy(struct fb_info *info)
283 {
284 	if (info->screen_base)
285 		iounmap(info->screen_base);
286 	release_mem_region(info->apertures->ranges[0].base, info->apertures->ranges[0].size);
287 	framebuffer_release(info);
288 }
289 
290 static struct fb_ops offb_ops = {
291 	.owner		= THIS_MODULE,
292 	.fb_destroy	= offb_destroy,
293 	.fb_setcolreg	= offb_setcolreg,
294 	.fb_set_par	= offb_set_par,
295 	.fb_blank	= offb_blank,
296 	.fb_fillrect	= cfb_fillrect,
297 	.fb_copyarea	= cfb_copyarea,
298 	.fb_imageblit	= cfb_imageblit,
299 };
300 
301 static void __iomem *offb_map_reg(struct device_node *np, int index,
302 				  unsigned long offset, unsigned long size)
303 {
304 	const __be32 *addrp;
305 	u64 asize, taddr;
306 	unsigned int flags;
307 
308 	addrp = of_get_pci_address(np, index, &asize, &flags);
309 	if (addrp == NULL)
310 		addrp = of_get_address(np, index, &asize, &flags);
311 	if (addrp == NULL)
312 		return NULL;
313 	if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
314 		return NULL;
315 	if ((offset + size) > asize)
316 		return NULL;
317 	taddr = of_translate_address(np, addrp);
318 	if (taddr == OF_BAD_ADDR)
319 		return NULL;
320 	return ioremap(taddr + offset, size);
321 }
322 
323 static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp,
324 				    const char *name, unsigned long address)
325 {
326 	struct offb_par *par = (struct offb_par *) info->par;
327 
328 	if (dp && !strncmp(name, "ATY,Rage128", 11)) {
329 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
330 		if (par->cmap_adr)
331 			par->cmap_type = cmap_r128;
332 	} else if (dp && (!strncmp(name, "ATY,RageM3pA", 12)
333 			  || !strncmp(name, "ATY,RageM3p12A", 14))) {
334 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
335 		if (par->cmap_adr)
336 			par->cmap_type = cmap_M3A;
337 	} else if (dp && !strncmp(name, "ATY,RageM3pB", 12)) {
338 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
339 		if (par->cmap_adr)
340 			par->cmap_type = cmap_M3B;
341 	} else if (dp && !strncmp(name, "ATY,Rage6", 9)) {
342 		par->cmap_adr = offb_map_reg(dp, 1, 0, 0x1fff);
343 		if (par->cmap_adr)
344 			par->cmap_type = cmap_radeon;
345 	} else if (!strncmp(name, "ATY,", 4)) {
346 		unsigned long base = address & 0xff000000UL;
347 		par->cmap_adr =
348 			ioremap(base + 0x7ff000, 0x1000) + 0xcc0;
349 		par->cmap_data = par->cmap_adr + 1;
350 		par->cmap_type = cmap_simple;
351 	} else if (dp && (of_device_is_compatible(dp, "pci1014,b7") ||
352 			  of_device_is_compatible(dp, "pci1014,21c"))) {
353 		par->cmap_adr = offb_map_reg(dp, 0, 0x6000, 0x1000);
354 		if (par->cmap_adr)
355 			par->cmap_type = cmap_gxt2000;
356 	} else if (dp && !strncmp(name, "vga,Display-", 12)) {
357 		/* Look for AVIVO initialized by SLOF */
358 		struct device_node *pciparent = of_get_parent(dp);
359 		const u32 *vid, *did;
360 		vid = of_get_property(pciparent, "vendor-id", NULL);
361 		did = of_get_property(pciparent, "device-id", NULL);
362 		/* This will match most R5xx */
363 		if (vid && did && *vid == 0x1002 &&
364 		    ((*did >= 0x7100 && *did < 0x7800) ||
365 		     (*did >= 0x9400))) {
366 			par->cmap_adr = offb_map_reg(pciparent, 2, 0, 0x10000);
367 			if (par->cmap_adr)
368 				par->cmap_type = cmap_avivo;
369 		}
370 		of_node_put(pciparent);
371 	} else if (dp && of_device_is_compatible(dp, "qemu,std-vga")) {
372 #ifdef __BIG_ENDIAN
373 		const __be32 io_of_addr[3] = { 0x01000000, 0x0, 0x0 };
374 #else
375 		const __be32 io_of_addr[3] = { 0x00000001, 0x0, 0x0 };
376 #endif
377 		u64 io_addr = of_translate_address(dp, io_of_addr);
378 		if (io_addr != OF_BAD_ADDR) {
379 			par->cmap_adr = ioremap(io_addr + 0x3c8, 2);
380 			if (par->cmap_adr) {
381 				par->cmap_type = cmap_simple;
382 				par->cmap_data = par->cmap_adr + 1;
383 			}
384 		}
385 	}
386 	info->fix.visual = (par->cmap_type != cmap_unknown) ?
387 		FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_STATIC_PSEUDOCOLOR;
388 }
389 
390 static void __init offb_init_fb(const char *name, const char *full_name,
391 				int width, int height, int depth,
392 				int pitch, unsigned long address,
393 				int foreign_endian, struct device_node *dp)
394 {
395 	unsigned long res_size = pitch * height;
396 	struct offb_par *par = &default_par;
397 	unsigned long res_start = address;
398 	struct fb_fix_screeninfo *fix;
399 	struct fb_var_screeninfo *var;
400 	struct fb_info *info;
401 
402 	if (!request_mem_region(res_start, res_size, "offb"))
403 		return;
404 
405 	printk(KERN_INFO
406 	       "Using unsupported %dx%d %s at %lx, depth=%d, pitch=%d\n",
407 	       width, height, name, address, depth, pitch);
408 	if (depth != 8 && depth != 15 && depth != 16 && depth != 32) {
409 		printk(KERN_ERR "%s: can't use depth = %d\n", full_name,
410 		       depth);
411 		release_mem_region(res_start, res_size);
412 		return;
413 	}
414 
415 	info = framebuffer_alloc(sizeof(u32) * 16, NULL);
416 
417 	if (info == 0) {
418 		release_mem_region(res_start, res_size);
419 		return;
420 	}
421 
422 	fix = &info->fix;
423 	var = &info->var;
424 	info->par = par;
425 
426 	strcpy(fix->id, "OFfb ");
427 	strncat(fix->id, name, sizeof(fix->id) - sizeof("OFfb "));
428 	fix->id[sizeof(fix->id) - 1] = '\0';
429 
430 	var->xres = var->xres_virtual = width;
431 	var->yres = var->yres_virtual = height;
432 	fix->line_length = pitch;
433 
434 	fix->smem_start = address;
435 	fix->smem_len = pitch * height;
436 	fix->type = FB_TYPE_PACKED_PIXELS;
437 	fix->type_aux = 0;
438 
439 	par->cmap_type = cmap_unknown;
440 	if (depth == 8)
441 		offb_init_palette_hacks(info, dp, name, address);
442 	else
443 		fix->visual = FB_VISUAL_TRUECOLOR;
444 
445 	var->xoffset = var->yoffset = 0;
446 	switch (depth) {
447 	case 8:
448 		var->bits_per_pixel = 8;
449 		var->red.offset = 0;
450 		var->red.length = 8;
451 		var->green.offset = 0;
452 		var->green.length = 8;
453 		var->blue.offset = 0;
454 		var->blue.length = 8;
455 		var->transp.offset = 0;
456 		var->transp.length = 0;
457 		break;
458 	case 15:		/* RGB 555 */
459 		var->bits_per_pixel = 16;
460 		var->red.offset = 10;
461 		var->red.length = 5;
462 		var->green.offset = 5;
463 		var->green.length = 5;
464 		var->blue.offset = 0;
465 		var->blue.length = 5;
466 		var->transp.offset = 0;
467 		var->transp.length = 0;
468 		break;
469 	case 16:		/* RGB 565 */
470 		var->bits_per_pixel = 16;
471 		var->red.offset = 11;
472 		var->red.length = 5;
473 		var->green.offset = 5;
474 		var->green.length = 6;
475 		var->blue.offset = 0;
476 		var->blue.length = 5;
477 		var->transp.offset = 0;
478 		var->transp.length = 0;
479 		break;
480 	case 32:		/* RGB 888 */
481 		var->bits_per_pixel = 32;
482 		var->red.offset = 16;
483 		var->red.length = 8;
484 		var->green.offset = 8;
485 		var->green.length = 8;
486 		var->blue.offset = 0;
487 		var->blue.length = 8;
488 		var->transp.offset = 24;
489 		var->transp.length = 8;
490 		break;
491 	}
492 	var->red.msb_right = var->green.msb_right = var->blue.msb_right =
493 	    var->transp.msb_right = 0;
494 	var->grayscale = 0;
495 	var->nonstd = 0;
496 	var->activate = 0;
497 	var->height = var->width = -1;
498 	var->pixclock = 10000;
499 	var->left_margin = var->right_margin = 16;
500 	var->upper_margin = var->lower_margin = 16;
501 	var->hsync_len = var->vsync_len = 8;
502 	var->sync = 0;
503 	var->vmode = FB_VMODE_NONINTERLACED;
504 
505 	/* set offb aperture size for generic probing */
506 	info->apertures = alloc_apertures(1);
507 	if (!info->apertures)
508 		goto out_aper;
509 	info->apertures->ranges[0].base = address;
510 	info->apertures->ranges[0].size = fix->smem_len;
511 
512 	info->fbops = &offb_ops;
513 	info->screen_base = ioremap(address, fix->smem_len);
514 	info->pseudo_palette = (void *) (info + 1);
515 	info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE | foreign_endian;
516 
517 	fb_alloc_cmap(&info->cmap, 256, 0);
518 
519 	if (register_framebuffer(info) < 0)
520 		goto out_err;
521 
522 	fb_info(info, "Open Firmware frame buffer device on %s\n", full_name);
523 	return;
524 
525 out_err:
526 	iounmap(info->screen_base);
527 out_aper:
528 	iounmap(par->cmap_adr);
529 	par->cmap_adr = NULL;
530 	framebuffer_release(info);
531 	release_mem_region(res_start, res_size);
532 }
533 
534 
535 static void __init offb_init_nodriver(struct device_node *dp, int no_real_node)
536 {
537 	unsigned int len;
538 	int i, width = 640, height = 480, depth = 8, pitch = 640;
539 	unsigned int flags, rsize, addr_prop = 0;
540 	unsigned long max_size = 0;
541 	u64 rstart, address = OF_BAD_ADDR;
542 	const __be32 *pp, *addrp, *up;
543 	u64 asize;
544 	int foreign_endian = 0;
545 
546 #ifdef __BIG_ENDIAN
547 	if (of_get_property(dp, "little-endian", NULL))
548 		foreign_endian = FBINFO_FOREIGN_ENDIAN;
549 #else
550 	if (of_get_property(dp, "big-endian", NULL))
551 		foreign_endian = FBINFO_FOREIGN_ENDIAN;
552 #endif
553 
554 	pp = of_get_property(dp, "linux,bootx-depth", &len);
555 	if (pp == NULL)
556 		pp = of_get_property(dp, "depth", &len);
557 	if (pp && len == sizeof(u32))
558 		depth = be32_to_cpup(pp);
559 
560 	pp = of_get_property(dp, "linux,bootx-width", &len);
561 	if (pp == NULL)
562 		pp = of_get_property(dp, "width", &len);
563 	if (pp && len == sizeof(u32))
564 		width = be32_to_cpup(pp);
565 
566 	pp = of_get_property(dp, "linux,bootx-height", &len);
567 	if (pp == NULL)
568 		pp = of_get_property(dp, "height", &len);
569 	if (pp && len == sizeof(u32))
570 		height = be32_to_cpup(pp);
571 
572 	pp = of_get_property(dp, "linux,bootx-linebytes", &len);
573 	if (pp == NULL)
574 		pp = of_get_property(dp, "linebytes", &len);
575 	if (pp && len == sizeof(u32) && (*pp != 0xffffffffu))
576 		pitch = be32_to_cpup(pp);
577 	else
578 		pitch = width * ((depth + 7) / 8);
579 
580 	rsize = (unsigned long)pitch * (unsigned long)height;
581 
582 	/* Ok, now we try to figure out the address of the framebuffer.
583 	 *
584 	 * Unfortunately, Open Firmware doesn't provide a standard way to do
585 	 * so. All we can do is a dodgy heuristic that happens to work in
586 	 * practice. On most machines, the "address" property contains what
587 	 * we need, though not on Matrox cards found in IBM machines. What I've
588 	 * found that appears to give good results is to go through the PCI
589 	 * ranges and pick one that is both big enough and if possible encloses
590 	 * the "address" property. If none match, we pick the biggest
591 	 */
592 	up = of_get_property(dp, "linux,bootx-addr", &len);
593 	if (up == NULL)
594 		up = of_get_property(dp, "address", &len);
595 	if (up && len == sizeof(u32))
596 		addr_prop = *up;
597 
598 	/* Hack for when BootX is passing us */
599 	if (no_real_node)
600 		goto skip_addr;
601 
602 	for (i = 0; (addrp = of_get_address(dp, i, &asize, &flags))
603 		     != NULL; i++) {
604 		int match_addrp = 0;
605 
606 		if (!(flags & IORESOURCE_MEM))
607 			continue;
608 		if (asize < rsize)
609 			continue;
610 		rstart = of_translate_address(dp, addrp);
611 		if (rstart == OF_BAD_ADDR)
612 			continue;
613 		if (addr_prop && (rstart <= addr_prop) &&
614 		    ((rstart + asize) >= (addr_prop + rsize)))
615 			match_addrp = 1;
616 		if (match_addrp) {
617 			address = addr_prop;
618 			break;
619 		}
620 		if (rsize > max_size) {
621 			max_size = rsize;
622 			address = OF_BAD_ADDR;
623  		}
624 
625 		if (address == OF_BAD_ADDR)
626 			address = rstart;
627 	}
628  skip_addr:
629 	if (address == OF_BAD_ADDR && addr_prop)
630 		address = (u64)addr_prop;
631 	if (address != OF_BAD_ADDR) {
632 		/* kludge for valkyrie */
633 		if (strcmp(dp->name, "valkyrie") == 0)
634 			address += 0x1000;
635 		offb_init_fb(no_real_node ? "bootx" : dp->name,
636 			     no_real_node ? "display" : dp->full_name,
637 			     width, height, depth, pitch, address,
638 			     foreign_endian, no_real_node ? NULL : dp);
639 	}
640 }
641 
642 static int __init offb_init(void)
643 {
644 	struct device_node *dp = NULL, *boot_disp = NULL;
645 
646 	if (fb_get_options("offb", NULL))
647 		return -ENODEV;
648 
649 	/* Check if we have a MacOS display without a node spec */
650 	if (of_get_property(of_chosen, "linux,bootx-noscreen", NULL) != NULL) {
651 		/* The old code tried to work out which node was the MacOS
652 		 * display based on the address. I'm dropping that since the
653 		 * lack of a node spec only happens with old BootX versions
654 		 * (users can update) and with this code, they'll still get
655 		 * a display (just not the palette hacks).
656 		 */
657 		offb_init_nodriver(of_chosen, 1);
658 	}
659 
660 	for (dp = NULL; (dp = of_find_node_by_type(dp, "display"));) {
661 		if (of_get_property(dp, "linux,opened", NULL) &&
662 		    of_get_property(dp, "linux,boot-display", NULL)) {
663 			boot_disp = dp;
664 			offb_init_nodriver(dp, 0);
665 		}
666 	}
667 	for (dp = NULL; (dp = of_find_node_by_type(dp, "display"));) {
668 		if (of_get_property(dp, "linux,opened", NULL) &&
669 		    dp != boot_disp)
670 			offb_init_nodriver(dp, 0);
671 	}
672 
673 	return 0;
674 }
675 
676 
677 module_init(offb_init);
678 MODULE_LICENSE("GPL");
679