xref: /linux/drivers/video/fbdev/offb.c (revision 00a6d7b6762c27d441e9ac8faff36384bc0fc180)
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 #define FB_RIGHT_POS(p, bpp)         (fb_be_math(p) ? 0 : (32 - (bpp)))
95 
96 static inline u32 offb_cmap_byteswap(struct fb_info *info, u32 value)
97 {
98 	u32 bpp = info->var.bits_per_pixel;
99 
100 	return cpu_to_be32(value) >> FB_RIGHT_POS(info, bpp);
101 }
102 
103     /*
104      *  Set a single color register. The values supplied are already
105      *  rounded down to the hardware's capabilities (according to the
106      *  entries in the var structure). Return != 0 for invalid regno.
107      */
108 
109 static int offb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
110 			  u_int transp, struct fb_info *info)
111 {
112 	struct offb_par *par = (struct offb_par *) info->par;
113 
114 	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
115 		u32 *pal = info->pseudo_palette;
116 		u32 cr = red >> (16 - info->var.red.length);
117 		u32 cg = green >> (16 - info->var.green.length);
118 		u32 cb = blue >> (16 - info->var.blue.length);
119 		u32 value;
120 
121 		if (regno >= 16)
122 			return -EINVAL;
123 
124 		value = (cr << info->var.red.offset) |
125 			(cg << info->var.green.offset) |
126 			(cb << info->var.blue.offset);
127 		if (info->var.transp.length > 0) {
128 			u32 mask = (1 << info->var.transp.length) - 1;
129 			mask <<= info->var.transp.offset;
130 			value |= mask;
131 		}
132 		pal[regno] = offb_cmap_byteswap(info, value);
133 		return 0;
134 	}
135 
136 	if (regno > 255)
137 		return -EINVAL;
138 
139 	red >>= 8;
140 	green >>= 8;
141 	blue >>= 8;
142 
143 	if (!par->cmap_adr)
144 		return 0;
145 
146 	switch (par->cmap_type) {
147 	case cmap_simple:
148 		writeb(regno, par->cmap_adr);
149 		writeb(red, par->cmap_data);
150 		writeb(green, par->cmap_data);
151 		writeb(blue, par->cmap_data);
152 		break;
153 	case cmap_M3A:
154 		/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
155 		out_le32(par->cmap_adr + 0x58,
156 			 in_le32(par->cmap_adr + 0x58) & ~0x20);
157 	case cmap_r128:
158 		/* Set palette index & data */
159 		out_8(par->cmap_adr + 0xb0, regno);
160 		out_le32(par->cmap_adr + 0xb4,
161 			 (red << 16 | green << 8 | blue));
162 		break;
163 	case cmap_M3B:
164 		/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
165 		out_le32(par->cmap_adr + 0x58,
166 			 in_le32(par->cmap_adr + 0x58) | 0x20);
167 		/* Set palette index & data */
168 		out_8(par->cmap_adr + 0xb0, regno);
169 		out_le32(par->cmap_adr + 0xb4, (red << 16 | green << 8 | blue));
170 		break;
171 	case cmap_radeon:
172 		/* Set palette index & data (could be smarter) */
173 		out_8(par->cmap_adr + 0xb0, regno);
174 		out_le32(par->cmap_adr + 0xb4, (red << 16 | green << 8 | blue));
175 		break;
176 	case cmap_gxt2000:
177 		out_le32(((unsigned __iomem *) par->cmap_adr) + regno,
178 			 (red << 16 | green << 8 | blue));
179 		break;
180 	case cmap_avivo:
181 		/* Write to both LUTs for now */
182 		writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
183 		writeb(regno, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
184 		writel(((red) << 22) | ((green) << 12) | ((blue) << 2),
185 		       par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
186 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
187 		writeb(regno, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
188 		writel(((red) << 22) | ((green) << 12) | ((blue) << 2),
189 		       par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
190 		break;
191 	}
192 
193 	return 0;
194 }
195 
196     /*
197      *  Blank the display.
198      */
199 
200 static int offb_blank(int blank, struct fb_info *info)
201 {
202 	struct offb_par *par = (struct offb_par *) info->par;
203 	int i, j;
204 
205 	if (!par->cmap_adr)
206 		return 0;
207 
208 	if (!par->blanked)
209 		if (!blank)
210 			return 0;
211 
212 	par->blanked = blank;
213 
214 	if (blank)
215 		for (i = 0; i < 256; i++) {
216 			switch (par->cmap_type) {
217 			case cmap_simple:
218 				writeb(i, par->cmap_adr);
219 				for (j = 0; j < 3; j++)
220 					writeb(0, par->cmap_data);
221 				break;
222 			case cmap_M3A:
223 				/* Clear PALETTE_ACCESS_CNTL in DAC_CNTL */
224 				out_le32(par->cmap_adr + 0x58,
225 					 in_le32(par->cmap_adr + 0x58) & ~0x20);
226 			case cmap_r128:
227 				/* Set palette index & data */
228 				out_8(par->cmap_adr + 0xb0, i);
229 				out_le32(par->cmap_adr + 0xb4, 0);
230 				break;
231 			case cmap_M3B:
232 				/* Set PALETTE_ACCESS_CNTL in DAC_CNTL */
233 				out_le32(par->cmap_adr + 0x58,
234 					 in_le32(par->cmap_adr + 0x58) | 0x20);
235 				/* Set palette index & data */
236 				out_8(par->cmap_adr + 0xb0, i);
237 				out_le32(par->cmap_adr + 0xb4, 0);
238 				break;
239 			case cmap_radeon:
240 				out_8(par->cmap_adr + 0xb0, i);
241 				out_le32(par->cmap_adr + 0xb4, 0);
242 				break;
243 			case cmap_gxt2000:
244 				out_le32(((unsigned __iomem *) par->cmap_adr) + i,
245 					 0);
246 				break;
247 			case cmap_avivo:
248 				writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
249 				writeb(i, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
250 				writel(0, par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
251 				writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
252 				writeb(i, par->cmap_adr + AVIVO_DC_LUT_RW_INDEX);
253 				writel(0, par->cmap_adr + AVIVO_DC_LUT_30_COLOR);
254 				break;
255 			}
256 	} else
257 		fb_set_cmap(&info->cmap, info);
258 	return 0;
259 }
260 
261 static int offb_set_par(struct fb_info *info)
262 {
263 	struct offb_par *par = (struct offb_par *) info->par;
264 
265 	/* On avivo, initialize palette control */
266 	if (par->cmap_type == cmap_avivo) {
267 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_CONTROL);
268 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_BLUE);
269 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_GREEN);
270 		writel(0, par->cmap_adr + AVIVO_DC_LUTA_BLACK_OFFSET_RED);
271 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_BLUE);
272 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_GREEN);
273 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTA_WHITE_OFFSET_RED);
274 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_CONTROL);
275 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_BLUE);
276 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_GREEN);
277 		writel(0, par->cmap_adr + AVIVO_DC_LUTB_BLACK_OFFSET_RED);
278 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_BLUE);
279 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_GREEN);
280 		writel(0x0000ffff, par->cmap_adr + AVIVO_DC_LUTB_WHITE_OFFSET_RED);
281 		writel(1, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
282 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_MODE);
283 		writel(0x0000003f, par->cmap_adr + AVIVO_DC_LUT_WRITE_EN_MASK);
284 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_SELECT);
285 		writel(0, par->cmap_adr + AVIVO_DC_LUT_RW_MODE);
286 		writel(0x0000003f, par->cmap_adr + AVIVO_DC_LUT_WRITE_EN_MASK);
287 	}
288 	return 0;
289 }
290 
291 static void offb_destroy(struct fb_info *info)
292 {
293 	if (info->screen_base)
294 		iounmap(info->screen_base);
295 	release_mem_region(info->apertures->ranges[0].base, info->apertures->ranges[0].size);
296 	framebuffer_release(info);
297 }
298 
299 static struct fb_ops offb_ops = {
300 	.owner		= THIS_MODULE,
301 	.fb_destroy	= offb_destroy,
302 	.fb_setcolreg	= offb_setcolreg,
303 	.fb_set_par	= offb_set_par,
304 	.fb_blank	= offb_blank,
305 	.fb_fillrect	= cfb_fillrect,
306 	.fb_copyarea	= cfb_copyarea,
307 	.fb_imageblit	= cfb_imageblit,
308 };
309 
310 static void __iomem *offb_map_reg(struct device_node *np, int index,
311 				  unsigned long offset, unsigned long size)
312 {
313 	const __be32 *addrp;
314 	u64 asize, taddr;
315 	unsigned int flags;
316 
317 	addrp = of_get_pci_address(np, index, &asize, &flags);
318 	if (addrp == NULL)
319 		addrp = of_get_address(np, index, &asize, &flags);
320 	if (addrp == NULL)
321 		return NULL;
322 	if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
323 		return NULL;
324 	if ((offset + size) > asize)
325 		return NULL;
326 	taddr = of_translate_address(np, addrp);
327 	if (taddr == OF_BAD_ADDR)
328 		return NULL;
329 	return ioremap(taddr + offset, size);
330 }
331 
332 static void offb_init_palette_hacks(struct fb_info *info, struct device_node *dp,
333 				    const char *name, unsigned long address)
334 {
335 	struct offb_par *par = (struct offb_par *) info->par;
336 
337 	if (dp && !strncmp(name, "ATY,Rage128", 11)) {
338 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
339 		if (par->cmap_adr)
340 			par->cmap_type = cmap_r128;
341 	} else if (dp && (!strncmp(name, "ATY,RageM3pA", 12)
342 			  || !strncmp(name, "ATY,RageM3p12A", 14))) {
343 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
344 		if (par->cmap_adr)
345 			par->cmap_type = cmap_M3A;
346 	} else if (dp && !strncmp(name, "ATY,RageM3pB", 12)) {
347 		par->cmap_adr = offb_map_reg(dp, 2, 0, 0x1fff);
348 		if (par->cmap_adr)
349 			par->cmap_type = cmap_M3B;
350 	} else if (dp && !strncmp(name, "ATY,Rage6", 9)) {
351 		par->cmap_adr = offb_map_reg(dp, 1, 0, 0x1fff);
352 		if (par->cmap_adr)
353 			par->cmap_type = cmap_radeon;
354 	} else if (!strncmp(name, "ATY,", 4)) {
355 		unsigned long base = address & 0xff000000UL;
356 		par->cmap_adr =
357 			ioremap(base + 0x7ff000, 0x1000) + 0xcc0;
358 		par->cmap_data = par->cmap_adr + 1;
359 		par->cmap_type = cmap_simple;
360 	} else if (dp && (of_device_is_compatible(dp, "pci1014,b7") ||
361 			  of_device_is_compatible(dp, "pci1014,21c"))) {
362 		par->cmap_adr = offb_map_reg(dp, 0, 0x6000, 0x1000);
363 		if (par->cmap_adr)
364 			par->cmap_type = cmap_gxt2000;
365 	} else if (dp && !strncmp(name, "vga,Display-", 12)) {
366 		/* Look for AVIVO initialized by SLOF */
367 		struct device_node *pciparent = of_get_parent(dp);
368 		const u32 *vid, *did;
369 		vid = of_get_property(pciparent, "vendor-id", NULL);
370 		did = of_get_property(pciparent, "device-id", NULL);
371 		/* This will match most R5xx */
372 		if (vid && did && *vid == 0x1002 &&
373 		    ((*did >= 0x7100 && *did < 0x7800) ||
374 		     (*did >= 0x9400))) {
375 			par->cmap_adr = offb_map_reg(pciparent, 2, 0, 0x10000);
376 			if (par->cmap_adr)
377 				par->cmap_type = cmap_avivo;
378 		}
379 		of_node_put(pciparent);
380 	} else if (dp && of_device_is_compatible(dp, "qemu,std-vga")) {
381 #ifdef __BIG_ENDIAN
382 		const __be32 io_of_addr[3] = { 0x01000000, 0x0, 0x0 };
383 #else
384 		const __be32 io_of_addr[3] = { 0x00000001, 0x0, 0x0 };
385 #endif
386 		u64 io_addr = of_translate_address(dp, io_of_addr);
387 		if (io_addr != OF_BAD_ADDR) {
388 			par->cmap_adr = ioremap(io_addr + 0x3c8, 2);
389 			if (par->cmap_adr) {
390 				par->cmap_type = cmap_simple;
391 				par->cmap_data = par->cmap_adr + 1;
392 			}
393 		}
394 	}
395 	info->fix.visual = (par->cmap_type != cmap_unknown) ?
396 		FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_STATIC_PSEUDOCOLOR;
397 }
398 
399 static void __init offb_init_fb(const char *name, const char *full_name,
400 				int width, int height, int depth,
401 				int pitch, unsigned long address,
402 				int foreign_endian, struct device_node *dp)
403 {
404 	unsigned long res_size = pitch * height;
405 	struct offb_par *par = &default_par;
406 	unsigned long res_start = address;
407 	struct fb_fix_screeninfo *fix;
408 	struct fb_var_screeninfo *var;
409 	struct fb_info *info;
410 
411 	if (!request_mem_region(res_start, res_size, "offb"))
412 		return;
413 
414 	printk(KERN_INFO
415 	       "Using unsupported %dx%d %s at %lx, depth=%d, pitch=%d\n",
416 	       width, height, name, address, depth, pitch);
417 	if (depth != 8 && depth != 15 && depth != 16 && depth != 32) {
418 		printk(KERN_ERR "%s: can't use depth = %d\n", full_name,
419 		       depth);
420 		release_mem_region(res_start, res_size);
421 		return;
422 	}
423 
424 	info = framebuffer_alloc(sizeof(u32) * 16, NULL);
425 
426 	if (info == 0) {
427 		release_mem_region(res_start, res_size);
428 		return;
429 	}
430 
431 	fix = &info->fix;
432 	var = &info->var;
433 	info->par = par;
434 
435 	strcpy(fix->id, "OFfb ");
436 	strncat(fix->id, name, sizeof(fix->id) - sizeof("OFfb "));
437 	fix->id[sizeof(fix->id) - 1] = '\0';
438 
439 	var->xres = var->xres_virtual = width;
440 	var->yres = var->yres_virtual = height;
441 	fix->line_length = pitch;
442 
443 	fix->smem_start = address;
444 	fix->smem_len = pitch * height;
445 	fix->type = FB_TYPE_PACKED_PIXELS;
446 	fix->type_aux = 0;
447 
448 	par->cmap_type = cmap_unknown;
449 	if (depth == 8)
450 		offb_init_palette_hacks(info, dp, name, address);
451 	else
452 		fix->visual = FB_VISUAL_TRUECOLOR;
453 
454 	var->xoffset = var->yoffset = 0;
455 	switch (depth) {
456 	case 8:
457 		var->bits_per_pixel = 8;
458 		var->red.offset = 0;
459 		var->red.length = 8;
460 		var->green.offset = 0;
461 		var->green.length = 8;
462 		var->blue.offset = 0;
463 		var->blue.length = 8;
464 		var->transp.offset = 0;
465 		var->transp.length = 0;
466 		break;
467 	case 15:		/* RGB 555 */
468 		var->bits_per_pixel = 16;
469 		var->red.offset = 10;
470 		var->red.length = 5;
471 		var->green.offset = 5;
472 		var->green.length = 5;
473 		var->blue.offset = 0;
474 		var->blue.length = 5;
475 		var->transp.offset = 0;
476 		var->transp.length = 0;
477 		break;
478 	case 16:		/* RGB 565 */
479 		var->bits_per_pixel = 16;
480 		var->red.offset = 11;
481 		var->red.length = 5;
482 		var->green.offset = 5;
483 		var->green.length = 6;
484 		var->blue.offset = 0;
485 		var->blue.length = 5;
486 		var->transp.offset = 0;
487 		var->transp.length = 0;
488 		break;
489 	case 32:		/* RGB 888 */
490 		var->bits_per_pixel = 32;
491 		var->red.offset = 16;
492 		var->red.length = 8;
493 		var->green.offset = 8;
494 		var->green.length = 8;
495 		var->blue.offset = 0;
496 		var->blue.length = 8;
497 		var->transp.offset = 24;
498 		var->transp.length = 8;
499 		break;
500 	}
501 	var->red.msb_right = var->green.msb_right = var->blue.msb_right =
502 	    var->transp.msb_right = 0;
503 	var->grayscale = 0;
504 	var->nonstd = 0;
505 	var->activate = 0;
506 	var->height = var->width = -1;
507 	var->pixclock = 10000;
508 	var->left_margin = var->right_margin = 16;
509 	var->upper_margin = var->lower_margin = 16;
510 	var->hsync_len = var->vsync_len = 8;
511 	var->sync = 0;
512 	var->vmode = FB_VMODE_NONINTERLACED;
513 
514 	/* set offb aperture size for generic probing */
515 	info->apertures = alloc_apertures(1);
516 	if (!info->apertures)
517 		goto out_aper;
518 	info->apertures->ranges[0].base = address;
519 	info->apertures->ranges[0].size = fix->smem_len;
520 
521 	info->fbops = &offb_ops;
522 	info->screen_base = ioremap(address, fix->smem_len);
523 	info->pseudo_palette = (void *) (info + 1);
524 	info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE | foreign_endian;
525 
526 	fb_alloc_cmap(&info->cmap, 256, 0);
527 
528 	if (register_framebuffer(info) < 0)
529 		goto out_err;
530 
531 	fb_info(info, "Open Firmware frame buffer device on %s\n", full_name);
532 	return;
533 
534 out_err:
535 	iounmap(info->screen_base);
536 out_aper:
537 	iounmap(par->cmap_adr);
538 	par->cmap_adr = NULL;
539 	framebuffer_release(info);
540 	release_mem_region(res_start, res_size);
541 }
542 
543 
544 static void __init offb_init_nodriver(struct device_node *dp, int no_real_node)
545 {
546 	unsigned int len;
547 	int i, width = 640, height = 480, depth = 8, pitch = 640;
548 	unsigned int flags, rsize, addr_prop = 0;
549 	unsigned long max_size = 0;
550 	u64 rstart, address = OF_BAD_ADDR;
551 	const __be32 *pp, *addrp, *up;
552 	u64 asize;
553 	int foreign_endian = 0;
554 
555 #ifdef __BIG_ENDIAN
556 	if (of_get_property(dp, "little-endian", NULL))
557 		foreign_endian = FBINFO_FOREIGN_ENDIAN;
558 #else
559 	if (of_get_property(dp, "big-endian", NULL))
560 		foreign_endian = FBINFO_FOREIGN_ENDIAN;
561 #endif
562 
563 	pp = of_get_property(dp, "linux,bootx-depth", &len);
564 	if (pp == NULL)
565 		pp = of_get_property(dp, "depth", &len);
566 	if (pp && len == sizeof(u32))
567 		depth = be32_to_cpup(pp);
568 
569 	pp = of_get_property(dp, "linux,bootx-width", &len);
570 	if (pp == NULL)
571 		pp = of_get_property(dp, "width", &len);
572 	if (pp && len == sizeof(u32))
573 		width = be32_to_cpup(pp);
574 
575 	pp = of_get_property(dp, "linux,bootx-height", &len);
576 	if (pp == NULL)
577 		pp = of_get_property(dp, "height", &len);
578 	if (pp && len == sizeof(u32))
579 		height = be32_to_cpup(pp);
580 
581 	pp = of_get_property(dp, "linux,bootx-linebytes", &len);
582 	if (pp == NULL)
583 		pp = of_get_property(dp, "linebytes", &len);
584 	if (pp && len == sizeof(u32) && (*pp != 0xffffffffu))
585 		pitch = be32_to_cpup(pp);
586 	else
587 		pitch = width * ((depth + 7) / 8);
588 
589 	rsize = (unsigned long)pitch * (unsigned long)height;
590 
591 	/* Ok, now we try to figure out the address of the framebuffer.
592 	 *
593 	 * Unfortunately, Open Firmware doesn't provide a standard way to do
594 	 * so. All we can do is a dodgy heuristic that happens to work in
595 	 * practice. On most machines, the "address" property contains what
596 	 * we need, though not on Matrox cards found in IBM machines. What I've
597 	 * found that appears to give good results is to go through the PCI
598 	 * ranges and pick one that is both big enough and if possible encloses
599 	 * the "address" property. If none match, we pick the biggest
600 	 */
601 	up = of_get_property(dp, "linux,bootx-addr", &len);
602 	if (up == NULL)
603 		up = of_get_property(dp, "address", &len);
604 	if (up && len == sizeof(u32))
605 		addr_prop = *up;
606 
607 	/* Hack for when BootX is passing us */
608 	if (no_real_node)
609 		goto skip_addr;
610 
611 	for (i = 0; (addrp = of_get_address(dp, i, &asize, &flags))
612 		     != NULL; i++) {
613 		int match_addrp = 0;
614 
615 		if (!(flags & IORESOURCE_MEM))
616 			continue;
617 		if (asize < rsize)
618 			continue;
619 		rstart = of_translate_address(dp, addrp);
620 		if (rstart == OF_BAD_ADDR)
621 			continue;
622 		if (addr_prop && (rstart <= addr_prop) &&
623 		    ((rstart + asize) >= (addr_prop + rsize)))
624 			match_addrp = 1;
625 		if (match_addrp) {
626 			address = addr_prop;
627 			break;
628 		}
629 		if (rsize > max_size) {
630 			max_size = rsize;
631 			address = OF_BAD_ADDR;
632  		}
633 
634 		if (address == OF_BAD_ADDR)
635 			address = rstart;
636 	}
637  skip_addr:
638 	if (address == OF_BAD_ADDR && addr_prop)
639 		address = (u64)addr_prop;
640 	if (address != OF_BAD_ADDR) {
641 		/* kludge for valkyrie */
642 		if (strcmp(dp->name, "valkyrie") == 0)
643 			address += 0x1000;
644 		offb_init_fb(no_real_node ? "bootx" : dp->name,
645 			     no_real_node ? "display" : dp->full_name,
646 			     width, height, depth, pitch, address,
647 			     foreign_endian, no_real_node ? NULL : dp);
648 	}
649 }
650 
651 static int __init offb_init(void)
652 {
653 	struct device_node *dp = NULL, *boot_disp = NULL;
654 
655 	if (fb_get_options("offb", NULL))
656 		return -ENODEV;
657 
658 	/* Check if we have a MacOS display without a node spec */
659 	if (of_get_property(of_chosen, "linux,bootx-noscreen", NULL) != NULL) {
660 		/* The old code tried to work out which node was the MacOS
661 		 * display based on the address. I'm dropping that since the
662 		 * lack of a node spec only happens with old BootX versions
663 		 * (users can update) and with this code, they'll still get
664 		 * a display (just not the palette hacks).
665 		 */
666 		offb_init_nodriver(of_chosen, 1);
667 	}
668 
669 	for (dp = NULL; (dp = of_find_node_by_type(dp, "display"));) {
670 		if (of_get_property(dp, "linux,opened", NULL) &&
671 		    of_get_property(dp, "linux,boot-display", NULL)) {
672 			boot_disp = dp;
673 			offb_init_nodriver(dp, 0);
674 		}
675 	}
676 	for (dp = NULL; (dp = of_find_node_by_type(dp, "display"));) {
677 		if (of_get_property(dp, "linux,opened", NULL) &&
678 		    dp != boot_disp)
679 			offb_init_nodriver(dp, 0);
680 	}
681 
682 	return 0;
683 }
684 
685 
686 module_init(offb_init);
687 MODULE_LICENSE("GPL");
688