Merge 'akpm' patch series
[linux-2.6.git] / drivers / video / acornfb.c
1 /*
2  *  linux/drivers/video/acornfb.c
3  *
4  *  Copyright (C) 1998-2001 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * Frame buffer code for Acorn platforms
11  *
12  * NOTE: Most of the modes with X!=640 will disappear shortly.
13  * NOTE: Startup setting of HS & VS polarity not supported.
14  *       (do we need to support it if we're coming up in 640x480?)
15  *
16  * FIXME: (things broken by the "new improved" FBCON API)
17  *  - Blanking 8bpp displays with VIDC
18  */
19
20 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/string.h>
24 #include <linux/ctype.h>
25 #include <linux/mm.h>
26 #include <linux/init.h>
27 #include <linux/fb.h>
28 #include <linux/platform_device.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/io.h>
31 #include <linux/gfp.h>
32
33 #include <mach/hardware.h>
34 #include <asm/irq.h>
35 #include <asm/mach-types.h>
36 #include <asm/pgtable.h>
37
38 #include "acornfb.h"
39
40 /*
41  * VIDC machines can't do 16 or 32BPP modes.
42  */
43 #ifdef HAS_VIDC
44 #undef FBCON_HAS_CFB16
45 #undef FBCON_HAS_CFB32
46 #endif
47
48 /*
49  * Default resolution.
50  * NOTE that it has to be supported in the table towards
51  * the end of this file.
52  */
53 #define DEFAULT_XRES    640
54 #define DEFAULT_YRES    480
55 #define DEFAULT_BPP     4
56
57 /*
58  * define this to debug the video mode selection
59  */
60 #undef DEBUG_MODE_SELECTION
61
62 /*
63  * Translation from RISC OS monitor types to actual
64  * HSYNC and VSYNC frequency ranges.  These are
65  * probably not right, but they're the best info I
66  * have.  Allow 1% either way on the nominal for TVs.
67  */
68 #define NR_MONTYPES     6
69 static struct fb_monspecs monspecs[NR_MONTYPES] __devinitdata = {
70         {       /* TV           */
71                 .hfmin  = 15469,
72                 .hfmax  = 15781,
73                 .vfmin  = 49,
74                 .vfmax  = 51,
75         }, {    /* Multi Freq   */
76                 .hfmin  = 0,
77                 .hfmax  = 99999,
78                 .vfmin  = 0,
79                 .vfmax  = 199,
80         }, {    /* Hi-res mono  */
81                 .hfmin  = 58608,
82                 .hfmax  = 58608,
83                 .vfmin  = 64,
84                 .vfmax  = 64,
85         }, {    /* VGA          */
86                 .hfmin  = 30000,
87                 .hfmax  = 70000,
88                 .vfmin  = 60,
89                 .vfmax  = 60,
90         }, {    /* SVGA         */
91                 .hfmin  = 30000,
92                 .hfmax  = 70000,
93                 .vfmin  = 56,
94                 .vfmax  = 75,
95         }, {
96                 .hfmin  = 30000,
97                 .hfmax  = 70000,
98                 .vfmin  = 60,
99                 .vfmax  = 60,
100         }
101 };
102
103 static struct fb_info fb_info;
104 static struct acornfb_par current_par;
105 static struct vidc_timing current_vidc;
106
107 extern unsigned int vram_size;  /* set by setup.c */
108
109 #ifdef HAS_VIDC
110
111 #define MAX_SIZE        480*1024
112
113 /* CTL     VIDC Actual
114  * 24.000  0     8.000
115  * 25.175  0     8.392
116  * 36.000  0    12.000
117  * 24.000  1    12.000
118  * 25.175  1    12.588
119  * 24.000  2    16.000
120  * 25.175  2    16.783
121  * 36.000  1    18.000
122  * 24.000  3    24.000
123  * 36.000  2    24.000
124  * 25.175  3    25.175
125  * 36.000  3    36.000
126  */
127 struct pixclock {
128         u_long  min_clock;
129         u_long  max_clock;
130         u_int   vidc_ctl;
131         u_int   vid_ctl;
132 };
133
134 static struct pixclock arc_clocks[] = {
135         /* we allow +/-1% on these */
136         { 123750, 126250, VIDC_CTRL_DIV3,   VID_CTL_24MHz },    /*  8.000MHz */
137         {  82500,  84167, VIDC_CTRL_DIV2,   VID_CTL_24MHz },    /* 12.000MHz */
138         {  61875,  63125, VIDC_CTRL_DIV1_5, VID_CTL_24MHz },    /* 16.000MHz */
139         {  41250,  42083, VIDC_CTRL_DIV1,   VID_CTL_24MHz },    /* 24.000MHz */
140 };
141
142 static struct pixclock *
143 acornfb_valid_pixrate(struct fb_var_screeninfo *var)
144 {
145         u_long pixclock = var->pixclock;
146         u_int i;
147
148         if (!var->pixclock)
149                 return NULL;
150
151         for (i = 0; i < ARRAY_SIZE(arc_clocks); i++)
152                 if (pixclock > arc_clocks[i].min_clock &&
153                     pixclock < arc_clocks[i].max_clock)
154                         return arc_clocks + i;
155
156         return NULL;
157 }
158
159 /* VIDC Rules:
160  * hcr  : must be even (interlace, hcr/2 must be even)
161  * hswr : must be even
162  * hdsr : must be odd
163  * hder : must be odd
164  *
165  * vcr  : must be odd
166  * vswr : >= 1
167  * vdsr : >= 1
168  * vder : >= vdsr
169  * if interlaced, then hcr/2 must be even
170  */
171 static void
172 acornfb_set_timing(struct fb_var_screeninfo *var)
173 {
174         struct pixclock *pclk;
175         struct vidc_timing vidc;
176         u_int horiz_correction;
177         u_int sync_len, display_start, display_end, cycle;
178         u_int is_interlaced;
179         u_int vid_ctl, vidc_ctl;
180         u_int bandwidth;
181
182         memset(&vidc, 0, sizeof(vidc));
183
184         pclk = acornfb_valid_pixrate(var);
185         vidc_ctl = pclk->vidc_ctl;
186         vid_ctl  = pclk->vid_ctl;
187
188         bandwidth = var->pixclock * 8 / var->bits_per_pixel;
189         /* 25.175, 4bpp = 79.444ns per byte, 317.776ns per word: fifo = 2,6 */
190         if (bandwidth > 143500)
191                 vidc_ctl |= VIDC_CTRL_FIFO_3_7;
192         else if (bandwidth > 71750)
193                 vidc_ctl |= VIDC_CTRL_FIFO_2_6;
194         else if (bandwidth > 35875)
195                 vidc_ctl |= VIDC_CTRL_FIFO_1_5;
196         else
197                 vidc_ctl |= VIDC_CTRL_FIFO_0_4;
198
199         switch (var->bits_per_pixel) {
200         case 1:
201                 horiz_correction = 19;
202                 vidc_ctl |= VIDC_CTRL_1BPP;
203                 break;
204
205         case 2:
206                 horiz_correction = 11;
207                 vidc_ctl |= VIDC_CTRL_2BPP;
208                 break;
209
210         case 4:
211                 horiz_correction = 7;
212                 vidc_ctl |= VIDC_CTRL_4BPP;
213                 break;
214
215         default:
216         case 8:
217                 horiz_correction = 5;
218                 vidc_ctl |= VIDC_CTRL_8BPP;
219                 break;
220         }
221
222         if (var->sync & FB_SYNC_COMP_HIGH_ACT) /* should be FB_SYNC_COMP */
223                 vidc_ctl |= VIDC_CTRL_CSYNC;
224         else {
225                 if (!(var->sync & FB_SYNC_HOR_HIGH_ACT))
226                         vid_ctl |= VID_CTL_HS_NHSYNC;
227
228                 if (!(var->sync & FB_SYNC_VERT_HIGH_ACT))
229                         vid_ctl |= VID_CTL_VS_NVSYNC;
230         }
231
232         sync_len        = var->hsync_len;
233         display_start   = sync_len + var->left_margin;
234         display_end     = display_start + var->xres;
235         cycle           = display_end + var->right_margin;
236
237         /* if interlaced, then hcr/2 must be even */
238         is_interlaced = (var->vmode & FB_VMODE_MASK) == FB_VMODE_INTERLACED;
239
240         if (is_interlaced) {
241                 vidc_ctl |= VIDC_CTRL_INTERLACE;
242                 if (cycle & 2) {
243                         cycle += 2;
244                         var->right_margin += 2;
245                 }
246         }
247
248         vidc.h_cycle            = (cycle - 2) / 2;
249         vidc.h_sync_width       = (sync_len - 2) / 2;
250         vidc.h_border_start     = (display_start - 1) / 2;
251         vidc.h_display_start    = (display_start - horiz_correction) / 2;
252         vidc.h_display_end      = (display_end - horiz_correction) / 2;
253         vidc.h_border_end       = (display_end - 1) / 2;
254         vidc.h_interlace        = (vidc.h_cycle + 1) / 2;
255
256         sync_len        = var->vsync_len;
257         display_start   = sync_len + var->upper_margin;
258         display_end     = display_start + var->yres;
259         cycle           = display_end + var->lower_margin;
260
261         if (is_interlaced)
262                 cycle = (cycle - 3) / 2;
263         else
264                 cycle = cycle - 1;
265
266         vidc.v_cycle            = cycle;
267         vidc.v_sync_width       = sync_len - 1;
268         vidc.v_border_start     = display_start - 1;
269         vidc.v_display_start    = vidc.v_border_start;
270         vidc.v_display_end      = display_end - 1;
271         vidc.v_border_end       = vidc.v_display_end;
272
273         if (machine_is_a5k())
274                 __raw_writeb(vid_ctl, IOEB_VID_CTL);
275
276         if (memcmp(&current_vidc, &vidc, sizeof(vidc))) {
277                 current_vidc = vidc;
278
279                 vidc_writel(0xe0000000 | vidc_ctl);
280                 vidc_writel(0x80000000 | (vidc.h_cycle << 14));
281                 vidc_writel(0x84000000 | (vidc.h_sync_width << 14));
282                 vidc_writel(0x88000000 | (vidc.h_border_start << 14));
283                 vidc_writel(0x8c000000 | (vidc.h_display_start << 14));
284                 vidc_writel(0x90000000 | (vidc.h_display_end << 14));
285                 vidc_writel(0x94000000 | (vidc.h_border_end << 14));
286                 vidc_writel(0x98000000);
287                 vidc_writel(0x9c000000 | (vidc.h_interlace << 14));
288                 vidc_writel(0xa0000000 | (vidc.v_cycle << 14));
289                 vidc_writel(0xa4000000 | (vidc.v_sync_width << 14));
290                 vidc_writel(0xa8000000 | (vidc.v_border_start << 14));
291                 vidc_writel(0xac000000 | (vidc.v_display_start << 14));
292                 vidc_writel(0xb0000000 | (vidc.v_display_end << 14));
293                 vidc_writel(0xb4000000 | (vidc.v_border_end << 14));
294                 vidc_writel(0xb8000000);
295                 vidc_writel(0xbc000000);
296         }
297 #ifdef DEBUG_MODE_SELECTION
298         printk(KERN_DEBUG "VIDC registers for %dx%dx%d:\n", var->xres,
299                var->yres, var->bits_per_pixel);
300         printk(KERN_DEBUG " H-cycle          : %d\n", vidc.h_cycle);
301         printk(KERN_DEBUG " H-sync-width     : %d\n", vidc.h_sync_width);
302         printk(KERN_DEBUG " H-border-start   : %d\n", vidc.h_border_start);
303         printk(KERN_DEBUG " H-display-start  : %d\n", vidc.h_display_start);
304         printk(KERN_DEBUG " H-display-end    : %d\n", vidc.h_display_end);
305         printk(KERN_DEBUG " H-border-end     : %d\n", vidc.h_border_end);
306         printk(KERN_DEBUG " H-interlace      : %d\n", vidc.h_interlace);
307         printk(KERN_DEBUG " V-cycle          : %d\n", vidc.v_cycle);
308         printk(KERN_DEBUG " V-sync-width     : %d\n", vidc.v_sync_width);
309         printk(KERN_DEBUG " V-border-start   : %d\n", vidc.v_border_start);
310         printk(KERN_DEBUG " V-display-start  : %d\n", vidc.v_display_start);
311         printk(KERN_DEBUG " V-display-end    : %d\n", vidc.v_display_end);
312         printk(KERN_DEBUG " V-border-end     : %d\n", vidc.v_border_end);
313         printk(KERN_DEBUG " VIDC Ctrl (E)    : 0x%08X\n", vidc_ctl);
314         printk(KERN_DEBUG " IOEB Ctrl        : 0x%08X\n", vid_ctl);
315 #endif
316 }
317
318 static int
319 acornfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
320                   u_int trans, struct fb_info *info)
321 {
322         union palette pal;
323
324         if (regno >= current_par.palette_size)
325                 return 1;
326
327         pal.p = 0;
328         pal.vidc.reg   = regno;
329         pal.vidc.red   = red >> 12;
330         pal.vidc.green = green >> 12;
331         pal.vidc.blue  = blue >> 12;
332
333         current_par.palette[regno] = pal;
334
335         vidc_writel(pal.p);
336
337         return 0;
338 }
339 #endif
340
341 #ifdef HAS_VIDC20
342 #include <mach/acornfb.h>
343
344 #define MAX_SIZE        2*1024*1024
345
346 /* VIDC20 has a different set of rules from the VIDC:
347  *  hcr  : must be multiple of 4
348  *  hswr : must be even
349  *  hdsr : must be even
350  *  hder : must be even
351  *  vcr  : >= 2, (interlace, must be odd)
352  *  vswr : >= 1
353  *  vdsr : >= 1
354  *  vder : >= vdsr
355  */
356 static void acornfb_set_timing(struct fb_info *info)
357 {
358         struct fb_var_screeninfo *var = &info->var;
359         struct vidc_timing vidc;
360         u_int vcr, fsize;
361         u_int ext_ctl, dat_ctl;
362         u_int words_per_line;
363
364         memset(&vidc, 0, sizeof(vidc));
365
366         vidc.h_sync_width       = var->hsync_len - 8;
367         vidc.h_border_start     = vidc.h_sync_width + var->left_margin + 8 - 12;
368         vidc.h_display_start    = vidc.h_border_start + 12 - 18;
369         vidc.h_display_end      = vidc.h_display_start + var->xres;
370         vidc.h_border_end       = vidc.h_display_end + 18 - 12;
371         vidc.h_cycle            = vidc.h_border_end + var->right_margin + 12 - 8;
372         vidc.h_interlace        = vidc.h_cycle / 2;
373         vidc.v_sync_width       = var->vsync_len - 1;
374         vidc.v_border_start     = vidc.v_sync_width + var->upper_margin;
375         vidc.v_display_start    = vidc.v_border_start;
376         vidc.v_display_end      = vidc.v_display_start + var->yres;
377         vidc.v_border_end       = vidc.v_display_end;
378         vidc.control            = acornfb_default_control();
379
380         vcr = var->vsync_len + var->upper_margin + var->yres +
381               var->lower_margin;
382
383         if ((var->vmode & FB_VMODE_MASK) == FB_VMODE_INTERLACED) {
384                 vidc.v_cycle = (vcr - 3) / 2;
385                 vidc.control |= VIDC20_CTRL_INT;
386         } else
387                 vidc.v_cycle = vcr - 2;
388
389         switch (var->bits_per_pixel) {
390         case  1: vidc.control |= VIDC20_CTRL_1BPP;      break;
391         case  2: vidc.control |= VIDC20_CTRL_2BPP;      break;
392         case  4: vidc.control |= VIDC20_CTRL_4BPP;      break;
393         default:
394         case  8: vidc.control |= VIDC20_CTRL_8BPP;      break;
395         case 16: vidc.control |= VIDC20_CTRL_16BPP;     break;
396         case 32: vidc.control |= VIDC20_CTRL_32BPP;     break;
397         }
398
399         acornfb_vidc20_find_rates(&vidc, var);
400         fsize = var->vsync_len + var->upper_margin + var->lower_margin - 1;
401
402         if (memcmp(&current_vidc, &vidc, sizeof(vidc))) {
403                 current_vidc = vidc;
404
405                 vidc_writel(VIDC20_CTRL| vidc.control);
406                 vidc_writel(0xd0000000 | vidc.pll_ctl);
407                 vidc_writel(0x80000000 | vidc.h_cycle);
408                 vidc_writel(0x81000000 | vidc.h_sync_width);
409                 vidc_writel(0x82000000 | vidc.h_border_start);
410                 vidc_writel(0x83000000 | vidc.h_display_start);
411                 vidc_writel(0x84000000 | vidc.h_display_end);
412                 vidc_writel(0x85000000 | vidc.h_border_end);
413                 vidc_writel(0x86000000);
414                 vidc_writel(0x87000000 | vidc.h_interlace);
415                 vidc_writel(0x90000000 | vidc.v_cycle);
416                 vidc_writel(0x91000000 | vidc.v_sync_width);
417                 vidc_writel(0x92000000 | vidc.v_border_start);
418                 vidc_writel(0x93000000 | vidc.v_display_start);
419                 vidc_writel(0x94000000 | vidc.v_display_end);
420                 vidc_writel(0x95000000 | vidc.v_border_end);
421                 vidc_writel(0x96000000);
422                 vidc_writel(0x97000000);
423         }
424
425         iomd_writel(fsize, IOMD_FSIZE);
426
427         ext_ctl = acornfb_default_econtrol();
428
429         if (var->sync & FB_SYNC_COMP_HIGH_ACT) /* should be FB_SYNC_COMP */
430                 ext_ctl |= VIDC20_ECTL_HS_NCSYNC | VIDC20_ECTL_VS_NCSYNC;
431         else {
432                 if (var->sync & FB_SYNC_HOR_HIGH_ACT)
433                         ext_ctl |= VIDC20_ECTL_HS_HSYNC;
434                 else
435                         ext_ctl |= VIDC20_ECTL_HS_NHSYNC;
436
437                 if (var->sync & FB_SYNC_VERT_HIGH_ACT)
438                         ext_ctl |= VIDC20_ECTL_VS_VSYNC;
439                 else
440                         ext_ctl |= VIDC20_ECTL_VS_NVSYNC;
441         }
442
443         vidc_writel(VIDC20_ECTL | ext_ctl);
444
445         words_per_line = var->xres * var->bits_per_pixel / 32;
446
447         if (current_par.using_vram && info->fix.smem_len == 2048*1024)
448                 words_per_line /= 2;
449
450         /* RiscPC doesn't use the VIDC's VRAM control. */
451         dat_ctl = VIDC20_DCTL_VRAM_DIS | VIDC20_DCTL_SNA | words_per_line;
452
453         /* The data bus width is dependent on both the type
454          * and amount of video memory.
455          *     DRAM     32bit low
456          * 1MB VRAM     32bit
457          * 2MB VRAM     64bit
458          */
459         if (current_par.using_vram && current_par.vram_half_sam == 2048)
460                 dat_ctl |= VIDC20_DCTL_BUS_D63_0;
461         else
462                 dat_ctl |= VIDC20_DCTL_BUS_D31_0;
463
464         vidc_writel(VIDC20_DCTL | dat_ctl);
465
466 #ifdef DEBUG_MODE_SELECTION
467         printk(KERN_DEBUG "VIDC registers for %dx%dx%d:\n", var->xres,
468                var->yres, var->bits_per_pixel);
469         printk(KERN_DEBUG " H-cycle          : %d\n", vidc.h_cycle);
470         printk(KERN_DEBUG " H-sync-width     : %d\n", vidc.h_sync_width);
471         printk(KERN_DEBUG " H-border-start   : %d\n", vidc.h_border_start);
472         printk(KERN_DEBUG " H-display-start  : %d\n", vidc.h_display_start);
473         printk(KERN_DEBUG " H-display-end    : %d\n", vidc.h_display_end);
474         printk(KERN_DEBUG " H-border-end     : %d\n", vidc.h_border_end);
475         printk(KERN_DEBUG " H-interlace      : %d\n", vidc.h_interlace);
476         printk(KERN_DEBUG " V-cycle          : %d\n", vidc.v_cycle);
477         printk(KERN_DEBUG " V-sync-width     : %d\n", vidc.v_sync_width);
478         printk(KERN_DEBUG " V-border-start   : %d\n", vidc.v_border_start);
479         printk(KERN_DEBUG " V-display-start  : %d\n", vidc.v_display_start);
480         printk(KERN_DEBUG " V-display-end    : %d\n", vidc.v_display_end);
481         printk(KERN_DEBUG " V-border-end     : %d\n", vidc.v_border_end);
482         printk(KERN_DEBUG " Ext Ctrl  (C)    : 0x%08X\n", ext_ctl);
483         printk(KERN_DEBUG " PLL Ctrl  (D)    : 0x%08X\n", vidc.pll_ctl);
484         printk(KERN_DEBUG " Ctrl      (E)    : 0x%08X\n", vidc.control);
485         printk(KERN_DEBUG " Data Ctrl (F)    : 0x%08X\n", dat_ctl);
486         printk(KERN_DEBUG " Fsize            : 0x%08X\n", fsize);
487 #endif
488 }
489
490 /*
491  * We have to take note of the VIDC20's 16-bit palette here.
492  * The VIDC20 looks up a 16 bit pixel as follows:
493  *
494  *   bits   111111
495  *          5432109876543210
496  *   red            ++++++++  (8 bits,  7 to 0)
497  *  green       ++++++++      (8 bits, 11 to 4)
498  *   blue   ++++++++          (8 bits, 15 to 8)
499  *
500  * We use a pixel which looks like:
501  *
502  *   bits   111111
503  *          5432109876543210
504  *   red               +++++  (5 bits,  4 to  0)
505  *  green         +++++       (5 bits,  9 to  5)
506  *   blue    +++++            (5 bits, 14 to 10)
507  */
508 static int
509 acornfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
510                   u_int trans, struct fb_info *info)
511 {
512         union palette pal;
513
514         if (regno >= current_par.palette_size)
515                 return 1;
516
517         if (regno < 16 && info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
518                 u32 pseudo_val;
519
520                 pseudo_val  = regno << info->var.red.offset;
521                 pseudo_val |= regno << info->var.green.offset;
522                 pseudo_val |= regno << info->var.blue.offset;
523
524                 ((u32 *)info->pseudo_palette)[regno] = pseudo_val;
525         }
526
527         pal.p = 0;
528         pal.vidc20.red   = red >> 8;
529         pal.vidc20.green = green >> 8;
530         pal.vidc20.blue  = blue >> 8;
531
532         current_par.palette[regno] = pal;
533
534         if (info->var.bits_per_pixel == 16) {
535                 int i;
536
537                 pal.p = 0;
538                 vidc_writel(0x10000000);
539                 for (i = 0; i < 256; i += 1) {
540                         pal.vidc20.red   = current_par.palette[ i       & 31].vidc20.red;
541                         pal.vidc20.green = current_par.palette[(i >> 1) & 31].vidc20.green;
542                         pal.vidc20.blue  = current_par.palette[(i >> 2) & 31].vidc20.blue;
543                         vidc_writel(pal.p);
544                         /* Palette register pointer auto-increments */
545                 }
546         } else {
547                 vidc_writel(0x10000000 | regno);
548                 vidc_writel(pal.p);
549         }
550
551         return 0;
552 }
553 #endif
554
555 /*
556  * Before selecting the timing parameters, adjust
557  * the resolution to fit the rules.
558  */
559 static int
560 acornfb_adjust_timing(struct fb_info *info, struct fb_var_screeninfo *var, u_int fontht)
561 {
562         u_int font_line_len, sam_size, min_size, size, nr_y;
563
564         /* xres must be even */
565         var->xres = (var->xres + 1) & ~1;
566
567         /*
568          * We don't allow xres_virtual to differ from xres
569          */
570         var->xres_virtual = var->xres;
571         var->xoffset = 0;
572
573         if (current_par.using_vram)
574                 sam_size = current_par.vram_half_sam * 2;
575         else
576                 sam_size = 16;
577
578         /*
579          * Now, find a value for yres_virtual which allows
580          * us to do ywrap scrolling.  The value of
581          * yres_virtual must be such that the end of the
582          * displayable frame buffer must be aligned with
583          * the start of a font line.
584          */
585         font_line_len = var->xres * var->bits_per_pixel * fontht / 8;
586         min_size = var->xres * var->yres * var->bits_per_pixel / 8;
587
588         /*
589          * If minimum screen size is greater than that we have
590          * available, reject it.
591          */
592         if (min_size > info->fix.smem_len)
593                 return -EINVAL;
594
595         /* Find int 'y', such that y * fll == s * sam < maxsize
596          * y = s * sam / fll; s = maxsize / sam
597          */
598         for (size = info->fix.smem_len;
599              nr_y = size / font_line_len, min_size <= size;
600              size -= sam_size) {
601                 if (nr_y * font_line_len == size)
602                         break;
603         }
604         nr_y *= fontht;
605
606         if (var->accel_flags & FB_ACCELF_TEXT) {
607                 if (min_size > size) {
608                         /*
609                          * failed, use ypan
610                          */
611                         size = info->fix.smem_len;
612                         var->yres_virtual = size / (font_line_len / fontht);
613                 } else
614                         var->yres_virtual = nr_y;
615         } else if (var->yres_virtual > nr_y)
616                 var->yres_virtual = nr_y;
617
618         current_par.screen_end = info->fix.smem_start + size;
619
620         /*
621          * Fix yres & yoffset if needed.
622          */
623         if (var->yres > var->yres_virtual)
624                 var->yres = var->yres_virtual;
625
626         if (var->vmode & FB_VMODE_YWRAP) {
627                 if (var->yoffset > var->yres_virtual)
628                         var->yoffset = var->yres_virtual;
629         } else {
630                 if (var->yoffset + var->yres > var->yres_virtual)
631                         var->yoffset = var->yres_virtual - var->yres;
632         }
633
634         /* hsync_len must be even */
635         var->hsync_len = (var->hsync_len + 1) & ~1;
636
637 #ifdef HAS_VIDC
638         /* left_margin must be odd */
639         if ((var->left_margin & 1) == 0) {
640                 var->left_margin -= 1;
641                 var->right_margin += 1;
642         }
643
644         /* right_margin must be odd */
645         var->right_margin |= 1;
646 #elif defined(HAS_VIDC20)
647         /* left_margin must be even */
648         if (var->left_margin & 1) {
649                 var->left_margin += 1;
650                 var->right_margin -= 1;
651         }
652
653         /* right_margin must be even */
654         if (var->right_margin & 1)
655                 var->right_margin += 1;
656 #endif
657
658         if (var->vsync_len < 1)
659                 var->vsync_len = 1;
660
661         return 0;
662 }
663
664 static int
665 acornfb_validate_timing(struct fb_var_screeninfo *var,
666                         struct fb_monspecs *monspecs)
667 {
668         unsigned long hs, vs;
669
670         /*
671          * hs(Hz) = 10^12 / (pixclock * xtotal)
672          * vs(Hz) = hs(Hz) / ytotal
673          *
674          * No need to do long long divisions or anything
675          * like that if you factor it correctly
676          */
677         hs = 1953125000 / var->pixclock;
678         hs = hs * 512 /
679              (var->xres + var->left_margin + var->right_margin + var->hsync_len);
680         vs = hs /
681              (var->yres + var->upper_margin + var->lower_margin + var->vsync_len);
682
683         return (vs >= monspecs->vfmin && vs <= monspecs->vfmax &&
684                 hs >= monspecs->hfmin && hs <= monspecs->hfmax) ? 0 : -EINVAL;
685 }
686
687 static inline void
688 acornfb_update_dma(struct fb_info *info, struct fb_var_screeninfo *var)
689 {
690         u_int off = var->yoffset * info->fix.line_length;
691
692 #if defined(HAS_MEMC)
693         memc_write(VDMA_INIT, off >> 2);
694 #elif defined(HAS_IOMD)
695         iomd_writel(info->fix.smem_start + off, IOMD_VIDINIT);
696 #endif
697 }
698
699 static int
700 acornfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
701 {
702         u_int fontht;
703         int err;
704
705         /*
706          * FIXME: Find the font height
707          */
708         fontht = 8;
709
710         var->red.msb_right = 0;
711         var->green.msb_right = 0;
712         var->blue.msb_right = 0;
713         var->transp.msb_right = 0;
714
715         switch (var->bits_per_pixel) {
716         case 1: case 2: case 4: case 8:
717                 var->red.offset    = 0;
718                 var->red.length    = var->bits_per_pixel;
719                 var->green         = var->red;
720                 var->blue          = var->red;
721                 var->transp.offset = 0;
722                 var->transp.length = 0;
723                 break;
724
725 #ifdef HAS_VIDC20
726         case 16:
727                 var->red.offset    = 0;
728                 var->red.length    = 5;
729                 var->green.offset  = 5;
730                 var->green.length  = 5;
731                 var->blue.offset   = 10;
732                 var->blue.length   = 5;
733                 var->transp.offset = 15;
734                 var->transp.length = 1;
735                 break;
736
737         case 32:
738                 var->red.offset    = 0;
739                 var->red.length    = 8;
740                 var->green.offset  = 8;
741                 var->green.length  = 8;
742                 var->blue.offset   = 16;
743                 var->blue.length   = 8;
744                 var->transp.offset = 24;
745                 var->transp.length = 4;
746                 break;
747 #endif
748         default:
749                 return -EINVAL;
750         }
751
752         /*
753          * Check to see if the pixel rate is valid.
754          */
755         if (!acornfb_valid_pixrate(var))
756                 return -EINVAL;
757
758         /*
759          * Validate and adjust the resolution to
760          * match the video generator hardware.
761          */
762         err = acornfb_adjust_timing(info, var, fontht);
763         if (err)
764                 return err;
765
766         /*
767          * Validate the timing against the
768          * monitor hardware.
769          */
770         return acornfb_validate_timing(var, &info->monspecs);
771 }
772
773 static int acornfb_set_par(struct fb_info *info)
774 {
775         switch (info->var.bits_per_pixel) {
776         case 1:
777                 current_par.palette_size = 2;
778                 info->fix.visual = FB_VISUAL_MONO10;
779                 break;
780         case 2:
781                 current_par.palette_size = 4;
782                 info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
783                 break;
784         case 4:
785                 current_par.palette_size = 16;
786                 info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
787                 break;
788         case 8:
789                 current_par.palette_size = VIDC_PALETTE_SIZE;
790 #ifdef HAS_VIDC
791                 info->fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
792 #else
793                 info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
794 #endif
795                 break;
796 #ifdef HAS_VIDC20
797         case 16:
798                 current_par.palette_size = 32;
799                 info->fix.visual = FB_VISUAL_DIRECTCOLOR;
800                 break;
801         case 32:
802                 current_par.palette_size = VIDC_PALETTE_SIZE;
803                 info->fix.visual = FB_VISUAL_DIRECTCOLOR;
804                 break;
805 #endif
806         default:
807                 BUG();
808         }
809
810         info->fix.line_length   = (info->var.xres * info->var.bits_per_pixel) / 8;
811
812 #if defined(HAS_MEMC)
813         {
814                 unsigned long size = info->fix.smem_len - VDMA_XFERSIZE;
815
816                 memc_write(VDMA_START, 0);
817                 memc_write(VDMA_END, size >> 2);
818         }
819 #elif defined(HAS_IOMD)
820         {
821                 unsigned long start, size;
822                 u_int control;
823
824                 start = info->fix.smem_start;
825                 size  = current_par.screen_end;
826
827                 if (current_par.using_vram) {
828                         size -= current_par.vram_half_sam;
829                         control = DMA_CR_E | (current_par.vram_half_sam / 256);
830                 } else {
831                         size -= 16;
832                         control = DMA_CR_E | DMA_CR_D | 16;
833                 }
834
835                 iomd_writel(start,   IOMD_VIDSTART);
836                 iomd_writel(size,    IOMD_VIDEND);
837                 iomd_writel(control, IOMD_VIDCR);
838         }
839 #endif
840
841         acornfb_update_dma(info, &info->var);
842         acornfb_set_timing(info);
843
844         return 0;
845 }
846
847 static int
848 acornfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
849 {
850         u_int y_bottom = var->yoffset;
851
852         if (!(var->vmode & FB_VMODE_YWRAP))
853                 y_bottom += var->yres;
854
855         BUG_ON(y_bottom > var->yres_virtual);
856
857         acornfb_update_dma(info, var);
858
859         return 0;
860 }
861
862 static struct fb_ops acornfb_ops = {
863         .owner          = THIS_MODULE,
864         .fb_check_var   = acornfb_check_var,
865         .fb_set_par     = acornfb_set_par,
866         .fb_setcolreg   = acornfb_setcolreg,
867         .fb_pan_display = acornfb_pan_display,
868         .fb_fillrect    = cfb_fillrect,
869         .fb_copyarea    = cfb_copyarea,
870         .fb_imageblit   = cfb_imageblit,
871 };
872
873 /*
874  * Everything after here is initialisation!!!
875  */
876 static struct fb_videomode modedb[] __devinitdata = {
877         {       /* 320x256 @ 50Hz */
878                 NULL, 50,  320,  256, 125000,  92,  62,  35, 19,  38, 2,
879                 FB_SYNC_COMP_HIGH_ACT,
880                 FB_VMODE_NONINTERLACED
881         }, {    /* 640x250 @ 50Hz, 15.6 kHz hsync */
882                 NULL, 50,  640,  250,  62500, 185, 123,  38, 21,  76, 3,
883                 0,
884                 FB_VMODE_NONINTERLACED
885         }, {    /* 640x256 @ 50Hz, 15.6 kHz hsync */
886                 NULL, 50,  640,  256,  62500, 185, 123,  35, 18,  76, 3,
887                 0,
888                 FB_VMODE_NONINTERLACED
889         }, {    /* 640x512 @ 50Hz, 26.8 kHz hsync */
890                 NULL, 50,  640,  512,  41667, 113,  87,  18,  1,  56, 3,
891                 0,
892                 FB_VMODE_NONINTERLACED
893         }, {    /* 640x250 @ 70Hz, 31.5 kHz hsync */
894                 NULL, 70,  640,  250,  39722,  48,  16, 109, 88,  96, 2,
895                 0,
896                 FB_VMODE_NONINTERLACED
897         }, {    /* 640x256 @ 70Hz, 31.5 kHz hsync */
898                 NULL, 70,  640,  256,  39722,  48,  16, 106, 85,  96, 2,
899                 0,
900                 FB_VMODE_NONINTERLACED
901         }, {    /* 640x352 @ 70Hz, 31.5 kHz hsync */
902                 NULL, 70,  640,  352,  39722,  48,  16,  58, 37,  96, 2,
903                 0,
904                 FB_VMODE_NONINTERLACED
905         }, {    /* 640x480 @ 60Hz, 31.5 kHz hsync */
906                 NULL, 60,  640,  480,  39722,  48,  16,  32, 11,  96, 2,
907                 0,
908                 FB_VMODE_NONINTERLACED
909         }, {    /* 800x600 @ 56Hz, 35.2 kHz hsync */
910                 NULL, 56,  800,  600,  27778, 101,  23,  22,  1, 100, 2,
911                 0,
912                 FB_VMODE_NONINTERLACED
913         }, {    /* 896x352 @ 60Hz, 21.8 kHz hsync */
914                 NULL, 60,  896,  352,  41667,  59,  27,   9,  0, 118, 3,
915                 0,
916                 FB_VMODE_NONINTERLACED
917         }, {    /* 1024x 768 @ 60Hz, 48.4 kHz hsync */
918                 NULL, 60, 1024,  768,  15385, 160,  24,  29,  3, 136, 6,
919                 0,
920                 FB_VMODE_NONINTERLACED
921         }, {    /* 1280x1024 @ 60Hz, 63.8 kHz hsync */
922                 NULL, 60, 1280, 1024,   9090, 186,  96,  38,  1, 160, 3,
923                 0,
924                 FB_VMODE_NONINTERLACED
925         }
926 };
927
928 static struct fb_videomode acornfb_default_mode __devinitdata = {
929         .name =         NULL,
930         .refresh =      60,
931         .xres =         640,
932         .yres =         480,
933         .pixclock =     39722,
934         .left_margin =  56,
935         .right_margin = 16,
936         .upper_margin = 34,
937         .lower_margin = 9,
938         .hsync_len =    88,
939         .vsync_len =    2,
940         .sync =         0,
941         .vmode =        FB_VMODE_NONINTERLACED
942 };
943
944 static void __devinit acornfb_init_fbinfo(void)
945 {
946         static int first = 1;
947
948         if (!first)
949                 return;
950         first = 0;
951
952         fb_info.fbops           = &acornfb_ops;
953         fb_info.flags           = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
954         fb_info.pseudo_palette  = current_par.pseudo_palette;
955
956         strcpy(fb_info.fix.id, "Acorn");
957         fb_info.fix.type        = FB_TYPE_PACKED_PIXELS;
958         fb_info.fix.type_aux    = 0;
959         fb_info.fix.xpanstep    = 0;
960         fb_info.fix.ypanstep    = 1;
961         fb_info.fix.ywrapstep   = 1;
962         fb_info.fix.line_length = 0;
963         fb_info.fix.accel       = FB_ACCEL_NONE;
964
965         /*
966          * setup initial parameters
967          */
968         memset(&fb_info.var, 0, sizeof(fb_info.var));
969
970 #if defined(HAS_VIDC20)
971         fb_info.var.red.length     = 8;
972         fb_info.var.transp.length  = 4;
973 #elif defined(HAS_VIDC)
974         fb_info.var.red.length     = 4;
975         fb_info.var.transp.length  = 1;
976 #endif
977         fb_info.var.green          = fb_info.var.red;
978         fb_info.var.blue           = fb_info.var.red;
979         fb_info.var.nonstd         = 0;
980         fb_info.var.activate       = FB_ACTIVATE_NOW;
981         fb_info.var.height         = -1;
982         fb_info.var.width          = -1;
983         fb_info.var.vmode          = FB_VMODE_NONINTERLACED;
984         fb_info.var.accel_flags    = FB_ACCELF_TEXT;
985
986         current_par.dram_size      = 0;
987         current_par.montype        = -1;
988         current_par.dpms           = 0;
989 }
990
991 /*
992  * setup acornfb options:
993  *
994  *  mon:hmin-hmax:vmin-vmax:dpms:width:height
995  *      Set monitor parameters:
996  *              hmin   = horizontal minimum frequency (Hz)
997  *              hmax   = horizontal maximum frequency (Hz)      (optional)
998  *              vmin   = vertical minimum frequency (Hz)
999  *              vmax   = vertical maximum frequency (Hz)        (optional)
1000  *              dpms   = DPMS supported?                        (optional)
1001  *              width  = width of picture in mm.                (optional)
1002  *              height = height of picture in mm.               (optional)
1003  *
1004  * montype:type
1005  *      Set RISC-OS style monitor type:
1006  *              0 (or tv)       - TV frequency
1007  *              1 (or multi)    - Multi frequency
1008  *              2 (or hires)    - Hi-res monochrome
1009  *              3 (or vga)      - VGA
1010  *              4 (or svga)     - SVGA
1011  *              auto, or option missing
1012  *                              - try hardware detect
1013  *
1014  * dram:size
1015  *      Set the amount of DRAM to use for the frame buffer
1016  *      (even if you have VRAM).
1017  *      size can optionally be followed by 'M' or 'K' for
1018  *      MB or KB respectively.
1019  */
1020 static void __devinit acornfb_parse_mon(char *opt)
1021 {
1022         char *p = opt;
1023
1024         current_par.montype = -2;
1025
1026         fb_info.monspecs.hfmin = simple_strtoul(p, &p, 0);
1027         if (*p == '-')
1028                 fb_info.monspecs.hfmax = simple_strtoul(p + 1, &p, 0);
1029         else
1030                 fb_info.monspecs.hfmax = fb_info.monspecs.hfmin;
1031
1032         if (*p != ':')
1033                 goto bad;
1034
1035         fb_info.monspecs.vfmin = simple_strtoul(p + 1, &p, 0);
1036         if (*p == '-')
1037                 fb_info.monspecs.vfmax = simple_strtoul(p + 1, &p, 0);
1038         else
1039                 fb_info.monspecs.vfmax = fb_info.monspecs.vfmin;
1040
1041         if (*p != ':')
1042                 goto check_values;
1043
1044         fb_info.monspecs.dpms = simple_strtoul(p + 1, &p, 0);
1045
1046         if (*p != ':')
1047                 goto check_values;
1048
1049         fb_info.var.width = simple_strtoul(p + 1, &p, 0);
1050
1051         if (*p != ':')
1052                 goto check_values;
1053
1054         fb_info.var.height = simple_strtoul(p + 1, NULL, 0);
1055
1056 check_values:
1057         if (fb_info.monspecs.hfmax < fb_info.monspecs.hfmin ||
1058             fb_info.monspecs.vfmax < fb_info.monspecs.vfmin)
1059                 goto bad;
1060         return;
1061
1062 bad:
1063         printk(KERN_ERR "Acornfb: bad monitor settings: %s\n", opt);
1064         current_par.montype = -1;
1065 }
1066
1067 static void __devinit acornfb_parse_montype(char *opt)
1068 {
1069         current_par.montype = -2;
1070
1071         if (strncmp(opt, "tv", 2) == 0) {
1072                 opt += 2;
1073                 current_par.montype = 0;
1074         } else if (strncmp(opt, "multi", 5) == 0) {
1075                 opt += 5;
1076                 current_par.montype = 1;
1077         } else if (strncmp(opt, "hires", 5) == 0) {
1078                 opt += 5;
1079                 current_par.montype = 2;
1080         } else if (strncmp(opt, "vga", 3) == 0) {
1081                 opt += 3;
1082                 current_par.montype = 3;
1083         } else if (strncmp(opt, "svga", 4) == 0) {
1084                 opt += 4;
1085                 current_par.montype = 4;
1086         } else if (strncmp(opt, "auto", 4) == 0) {
1087                 opt += 4;
1088                 current_par.montype = -1;
1089         } else if (isdigit(*opt))
1090                 current_par.montype = simple_strtoul(opt, &opt, 0);
1091
1092         if (current_par.montype == -2 ||
1093             current_par.montype > NR_MONTYPES) {
1094                 printk(KERN_ERR "acornfb: unknown monitor type: %s\n",
1095                         opt);
1096                 current_par.montype = -1;
1097         } else
1098         if (opt && *opt) {
1099                 if (strcmp(opt, ",dpms") == 0)
1100                         current_par.dpms = 1;
1101                 else
1102                         printk(KERN_ERR
1103                                "acornfb: unknown monitor option: %s\n",
1104                                opt);
1105         }
1106 }
1107
1108 static void __devinit acornfb_parse_dram(char *opt)
1109 {
1110         unsigned int size;
1111
1112         size = simple_strtoul(opt, &opt, 0);
1113
1114         if (opt) {
1115                 switch (*opt) {
1116                 case 'M':
1117                 case 'm':
1118                         size *= 1024;
1119                 case 'K':
1120                 case 'k':
1121                         size *= 1024;
1122                 default:
1123                         break;
1124                 }
1125         }
1126
1127         current_par.dram_size = size;
1128 }
1129
1130 static struct options {
1131         char *name;
1132         void (*parse)(char *opt);
1133 } opt_table[] __devinitdata = {
1134         { "mon",     acornfb_parse_mon     },
1135         { "montype", acornfb_parse_montype },
1136         { "dram",    acornfb_parse_dram    },
1137         { NULL, NULL }
1138 };
1139
1140 static int __devinit acornfb_setup(char *options)
1141 {
1142         struct options *optp;
1143         char *opt;
1144
1145         if (!options || !*options)
1146                 return 0;
1147
1148         acornfb_init_fbinfo();
1149
1150         while ((opt = strsep(&options, ",")) != NULL) {
1151                 if (!*opt)
1152                         continue;
1153
1154                 for (optp = opt_table; optp->name; optp++) {
1155                         int optlen;
1156
1157                         optlen = strlen(optp->name);
1158
1159                         if (strncmp(opt, optp->name, optlen) == 0 &&
1160                             opt[optlen] == ':') {
1161                                 optp->parse(opt + optlen + 1);
1162                                 break;
1163                         }
1164                 }
1165
1166                 if (!optp->name)
1167                         printk(KERN_ERR "acornfb: unknown parameter: %s\n",
1168                                opt);
1169         }
1170         return 0;
1171 }
1172
1173 /*
1174  * Detect type of monitor connected
1175  *  For now, we just assume SVGA
1176  */
1177 static int __devinit acornfb_detect_monitortype(void)
1178 {
1179         return 4;
1180 }
1181
1182 /*
1183  * This enables the unused memory to be freed on older Acorn machines.
1184  * We are freeing memory on behalf of the architecture initialisation
1185  * code here.
1186  */
1187 static inline void
1188 free_unused_pages(unsigned int virtual_start, unsigned int virtual_end)
1189 {
1190         int mb_freed = 0;
1191
1192         /*
1193          * Align addresses
1194          */
1195         virtual_start = PAGE_ALIGN(virtual_start);
1196         virtual_end = PAGE_ALIGN(virtual_end);
1197
1198         while (virtual_start < virtual_end) {
1199                 struct page *page;
1200
1201                 /*
1202                  * Clear page reserved bit,
1203                  * set count to 1, and free
1204                  * the page.
1205                  */
1206                 page = virt_to_page(virtual_start);
1207                 ClearPageReserved(page);
1208                 init_page_count(page);
1209                 free_page(virtual_start);
1210
1211                 virtual_start += PAGE_SIZE;
1212                 mb_freed += PAGE_SIZE / 1024;
1213         }
1214
1215         printk("acornfb: freed %dK memory\n", mb_freed);
1216 }
1217
1218 static int __devinit acornfb_probe(struct platform_device *dev)
1219 {
1220         unsigned long size;
1221         u_int h_sync, v_sync;
1222         int rc, i;
1223         char *option = NULL;
1224
1225         if (fb_get_options("acornfb", &option))
1226                 return -ENODEV;
1227         acornfb_setup(option);
1228
1229         acornfb_init_fbinfo();
1230
1231         current_par.dev = &dev->dev;
1232
1233         if (current_par.montype == -1)
1234                 current_par.montype = acornfb_detect_monitortype();
1235
1236         if (current_par.montype == -1 || current_par.montype > NR_MONTYPES)
1237                 current_par.montype = 4;
1238
1239         if (current_par.montype >= 0) {
1240                 fb_info.monspecs = monspecs[current_par.montype];
1241                 fb_info.monspecs.dpms = current_par.dpms;
1242         }
1243
1244         /*
1245          * Try to select a suitable default mode
1246          */
1247         for (i = 0; i < ARRAY_SIZE(modedb); i++) {
1248                 unsigned long hs;
1249
1250                 hs = modedb[i].refresh *
1251                      (modedb[i].yres + modedb[i].upper_margin +
1252                       modedb[i].lower_margin + modedb[i].vsync_len);
1253                 if (modedb[i].xres == DEFAULT_XRES &&
1254                     modedb[i].yres == DEFAULT_YRES &&
1255                     modedb[i].refresh >= fb_info.monspecs.vfmin &&
1256                     modedb[i].refresh <= fb_info.monspecs.vfmax &&
1257                     hs                >= fb_info.monspecs.hfmin &&
1258                     hs                <= fb_info.monspecs.hfmax) {
1259                         acornfb_default_mode = modedb[i];
1260                         break;
1261                 }
1262         }
1263
1264         fb_info.screen_base    = (char *)SCREEN_BASE;
1265         fb_info.fix.smem_start = SCREEN_START;
1266         current_par.using_vram = 0;
1267
1268         /*
1269          * If vram_size is set, we are using VRAM in
1270          * a Risc PC.  However, if the user has specified
1271          * an amount of DRAM then use that instead.
1272          */
1273         if (vram_size && !current_par.dram_size) {
1274                 size = vram_size;
1275                 current_par.vram_half_sam = vram_size / 1024;
1276                 current_par.using_vram = 1;
1277         } else if (current_par.dram_size)
1278                 size = current_par.dram_size;
1279         else
1280                 size = MAX_SIZE;
1281
1282         /*
1283          * Limit maximum screen size.
1284          */
1285         if (size > MAX_SIZE)
1286                 size = MAX_SIZE;
1287
1288         size = PAGE_ALIGN(size);
1289
1290 #if defined(HAS_VIDC20)
1291         if (!current_par.using_vram) {
1292                 dma_addr_t handle;
1293                 void *base;
1294
1295                 /*
1296                  * RiscPC needs to allocate the DRAM memory
1297                  * for the framebuffer if we are not using
1298                  * VRAM.
1299                  */
1300                 base = dma_alloc_writecombine(current_par.dev, size, &handle,
1301                                               GFP_KERNEL);
1302                 if (base == NULL) {
1303                         printk(KERN_ERR "acornfb: unable to allocate screen "
1304                                "memory\n");
1305                         return -ENOMEM;
1306                 }
1307
1308                 fb_info.screen_base = base;
1309                 fb_info.fix.smem_start = handle;
1310         }
1311 #endif
1312 #if defined(HAS_VIDC)
1313         /*
1314          * Archimedes/A5000 machines use a fixed address for their
1315          * framebuffers.  Free unused pages
1316          */
1317         free_unused_pages(PAGE_OFFSET + size, PAGE_OFFSET + MAX_SIZE);
1318 #endif
1319
1320         fb_info.fix.smem_len = size;
1321         current_par.palette_size   = VIDC_PALETTE_SIZE;
1322
1323         /*
1324          * Lookup the timing for this resolution.  If we can't
1325          * find it, then we can't restore it if we change
1326          * the resolution, so we disable this feature.
1327          */
1328         do {
1329                 rc = fb_find_mode(&fb_info.var, &fb_info, NULL, modedb,
1330                                  ARRAY_SIZE(modedb),
1331                                  &acornfb_default_mode, DEFAULT_BPP);
1332                 /*
1333                  * If we found an exact match, all ok.
1334                  */
1335                 if (rc == 1)
1336                         break;
1337
1338                 rc = fb_find_mode(&fb_info.var, &fb_info, NULL, NULL, 0,
1339                                   &acornfb_default_mode, DEFAULT_BPP);
1340                 /*
1341                  * If we found an exact match, all ok.
1342                  */
1343                 if (rc == 1)
1344                         break;
1345
1346                 rc = fb_find_mode(&fb_info.var, &fb_info, NULL, modedb,
1347                                  ARRAY_SIZE(modedb),
1348                                  &acornfb_default_mode, DEFAULT_BPP);
1349                 if (rc)
1350                         break;
1351
1352                 rc = fb_find_mode(&fb_info.var, &fb_info, NULL, NULL, 0,
1353                                   &acornfb_default_mode, DEFAULT_BPP);
1354         } while (0);
1355
1356         /*
1357          * If we didn't find an exact match, try the
1358          * generic database.
1359          */
1360         if (rc == 0) {
1361                 printk("Acornfb: no valid mode found\n");
1362                 return -EINVAL;
1363         }
1364
1365         h_sync = 1953125000 / fb_info.var.pixclock;
1366         h_sync = h_sync * 512 / (fb_info.var.xres + fb_info.var.left_margin +
1367                  fb_info.var.right_margin + fb_info.var.hsync_len);
1368         v_sync = h_sync / (fb_info.var.yres + fb_info.var.upper_margin +
1369                  fb_info.var.lower_margin + fb_info.var.vsync_len);
1370
1371         printk(KERN_INFO "Acornfb: %dkB %cRAM, %s, using %dx%d, "
1372                 "%d.%03dkHz, %dHz\n",
1373                 fb_info.fix.smem_len / 1024,
1374                 current_par.using_vram ? 'V' : 'D',
1375                 VIDC_NAME, fb_info.var.xres, fb_info.var.yres,
1376                 h_sync / 1000, h_sync % 1000, v_sync);
1377
1378         printk(KERN_INFO "Acornfb: Monitor: %d.%03d-%d.%03dkHz, %d-%dHz%s\n",
1379                 fb_info.monspecs.hfmin / 1000, fb_info.monspecs.hfmin % 1000,
1380                 fb_info.monspecs.hfmax / 1000, fb_info.monspecs.hfmax % 1000,
1381                 fb_info.monspecs.vfmin, fb_info.monspecs.vfmax,
1382                 fb_info.monspecs.dpms ? ", DPMS" : "");
1383
1384         if (fb_set_var(&fb_info, &fb_info.var))
1385                 printk(KERN_ERR "Acornfb: unable to set display parameters\n");
1386
1387         if (register_framebuffer(&fb_info) < 0)
1388                 return -EINVAL;
1389         return 0;
1390 }
1391
1392 static struct platform_driver acornfb_driver = {
1393         .probe  = acornfb_probe,
1394         .driver = {
1395                 .name   = "acornfb",
1396         },
1397 };
1398
1399 static int __init acornfb_init(void)
1400 {
1401         return platform_driver_register(&acornfb_driver);
1402 }
1403
1404 module_init(acornfb_init);
1405
1406 MODULE_AUTHOR("Russell King");
1407 MODULE_DESCRIPTION("VIDC 1/1a/20 framebuffer driver");
1408 MODULE_LICENSE("GPL");