xref: /openbmc/linux/drivers/video/fbdev/68328fb.c (revision 35267cea)
1 /*
2  *  linux/drivers/video/68328fb.c -- Low level implementation of the
3  *                                   mc68x328 LCD frame buffer device
4  *
5  *	Copyright (C) 2003 Georges Menie
6  *
7  *  This driver assumes an already configured controller (e.g. from config.c)
8  *  Keep the code clean of board specific initialization.
9  *
10  *  This code has not been tested with colors, colormap management functions
11  *  are minimal (no colormap data written to the 68328 registers...)
12  *
13  *  initial version of this driver:
14  *    Copyright (C) 1998,1999 Kenneth Albanowski <kjahds@kjahds.com>,
15  *                            The Silver Hammer Group, Ltd.
16  *
17  *  this version is based on :
18  *
19  *  linux/drivers/video/vfb.c -- Virtual frame buffer device
20  *
21  *      Copyright (C) 2002 James Simmons
22  *
23  *	Copyright (C) 1997 Geert Uytterhoeven
24  *
25  *  This file is subject to the terms and conditions of the GNU General Public
26  *  License. See the file COPYING in the main directory of this archive for
27  *  more details.
28  */
29 
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/errno.h>
33 #include <linux/string.h>
34 #include <linux/mm.h>
35 #include <linux/vmalloc.h>
36 #include <linux/delay.h>
37 #include <linux/interrupt.h>
38 #include <linux/uaccess.h>
39 #include <linux/fb.h>
40 #include <linux/init.h>
41 
42 #if defined(CONFIG_M68VZ328)
43 #include <asm/MC68VZ328.h>
44 #elif defined(CONFIG_M68EZ328)
45 #include <asm/MC68EZ328.h>
46 #elif defined(CONFIG_M68328)
47 #include <asm/MC68328.h>
48 #else
49 #error wrong architecture for the MC68x328 frame buffer device
50 #endif
51 
52 static u_long videomemory;
53 static u_long videomemorysize;
54 
55 static struct fb_info fb_info;
56 static u32 mc68x328fb_pseudo_palette[16];
57 
58 static struct fb_var_screeninfo mc68x328fb_default __initdata = {
59 	.red =		{ 0, 8, 0 },
60       	.green =	{ 0, 8, 0 },
61       	.blue =		{ 0, 8, 0 },
62       	.activate =	FB_ACTIVATE_TEST,
63       	.height =	-1,
64       	.width =	-1,
65       	.pixclock =	20000,
66       	.left_margin =	64,
67       	.right_margin =	64,
68       	.upper_margin =	32,
69       	.lower_margin =	32,
70       	.hsync_len =	64,
71       	.vsync_len =	2,
72       	.vmode =	FB_VMODE_NONINTERLACED,
73 };
74 
75 static const struct fb_fix_screeninfo mc68x328fb_fix __initconst = {
76 	.id =		"68328fb",
77 	.type =		FB_TYPE_PACKED_PIXELS,
78 	.xpanstep =	1,
79 	.ypanstep =	1,
80 	.ywrapstep =	1,
81 	.accel =	FB_ACCEL_NONE,
82 };
83 
84     /*
85      *  Interface used by the world
86      */
87 int mc68x328fb_init(void);
88 int mc68x328fb_setup(char *);
89 
90 static int mc68x328fb_check_var(struct fb_var_screeninfo *var,
91 			 struct fb_info *info);
92 static int mc68x328fb_set_par(struct fb_info *info);
93 static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
94 			 u_int transp, struct fb_info *info);
95 static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
96 			   struct fb_info *info);
97 static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma);
98 
99 static const struct fb_ops mc68x328fb_ops = {
100 	.fb_check_var	= mc68x328fb_check_var,
101 	.fb_set_par	= mc68x328fb_set_par,
102 	.fb_setcolreg	= mc68x328fb_setcolreg,
103 	.fb_pan_display	= mc68x328fb_pan_display,
104 	.fb_fillrect	= cfb_fillrect,
105 	.fb_copyarea	= cfb_copyarea,
106 	.fb_imageblit	= cfb_imageblit,
107 	.fb_mmap	= mc68x328fb_mmap,
108 };
109 
110     /*
111      *  Internal routines
112      */
113 
114 static u_long get_line_length(int xres_virtual, int bpp)
115 {
116 	u_long length;
117 
118 	length = xres_virtual * bpp;
119 	length = (length + 31) & ~31;
120 	length >>= 3;
121 	return (length);
122 }
123 
124     /*
125      *  Setting the video mode has been split into two parts.
126      *  First part, xxxfb_check_var, must not write anything
127      *  to hardware, it should only verify and adjust var.
128      *  This means it doesn't alter par but it does use hardware
129      *  data from it to check this var.
130      */
131 
132 static int mc68x328fb_check_var(struct fb_var_screeninfo *var,
133 			 struct fb_info *info)
134 {
135 	u_long line_length;
136 
137 	/*
138 	 *  FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
139 	 *  as FB_VMODE_SMOOTH_XPAN is only used internally
140 	 */
141 
142 	if (var->vmode & FB_VMODE_CONUPDATE) {
143 		var->vmode |= FB_VMODE_YWRAP;
144 		var->xoffset = info->var.xoffset;
145 		var->yoffset = info->var.yoffset;
146 	}
147 
148 	/*
149 	 *  Some very basic checks
150 	 */
151 	if (!var->xres)
152 		var->xres = 1;
153 	if (!var->yres)
154 		var->yres = 1;
155 	if (var->xres > var->xres_virtual)
156 		var->xres_virtual = var->xres;
157 	if (var->yres > var->yres_virtual)
158 		var->yres_virtual = var->yres;
159 	if (var->bits_per_pixel <= 1)
160 		var->bits_per_pixel = 1;
161 	else if (var->bits_per_pixel <= 8)
162 		var->bits_per_pixel = 8;
163 	else if (var->bits_per_pixel <= 16)
164 		var->bits_per_pixel = 16;
165 	else if (var->bits_per_pixel <= 24)
166 		var->bits_per_pixel = 24;
167 	else if (var->bits_per_pixel <= 32)
168 		var->bits_per_pixel = 32;
169 	else
170 		return -EINVAL;
171 
172 	if (var->xres_virtual < var->xoffset + var->xres)
173 		var->xres_virtual = var->xoffset + var->xres;
174 	if (var->yres_virtual < var->yoffset + var->yres)
175 		var->yres_virtual = var->yoffset + var->yres;
176 
177 	/*
178 	 *  Memory limit
179 	 */
180 	line_length =
181 	    get_line_length(var->xres_virtual, var->bits_per_pixel);
182 	if (line_length * var->yres_virtual > videomemorysize)
183 		return -ENOMEM;
184 
185 	/*
186 	 * Now that we checked it we alter var. The reason being is that the video
187 	 * mode passed in might not work but slight changes to it might make it
188 	 * work. This way we let the user know what is acceptable.
189 	 */
190 	switch (var->bits_per_pixel) {
191 	case 1:
192 		var->red.offset = 0;
193 		var->red.length = 1;
194 		var->green.offset = 0;
195 		var->green.length = 1;
196 		var->blue.offset = 0;
197 		var->blue.length = 1;
198 		var->transp.offset = 0;
199 		var->transp.length = 0;
200 		break;
201 	case 8:
202 		var->red.offset = 0;
203 		var->red.length = 8;
204 		var->green.offset = 0;
205 		var->green.length = 8;
206 		var->blue.offset = 0;
207 		var->blue.length = 8;
208 		var->transp.offset = 0;
209 		var->transp.length = 0;
210 		break;
211 	case 16:		/* RGBA 5551 */
212 		if (var->transp.length) {
213 			var->red.offset = 0;
214 			var->red.length = 5;
215 			var->green.offset = 5;
216 			var->green.length = 5;
217 			var->blue.offset = 10;
218 			var->blue.length = 5;
219 			var->transp.offset = 15;
220 			var->transp.length = 1;
221 		} else {	/* RGB 565 */
222 			var->red.offset = 0;
223 			var->red.length = 5;
224 			var->green.offset = 5;
225 			var->green.length = 6;
226 			var->blue.offset = 11;
227 			var->blue.length = 5;
228 			var->transp.offset = 0;
229 			var->transp.length = 0;
230 		}
231 		break;
232 	case 24:		/* RGB 888 */
233 		var->red.offset = 0;
234 		var->red.length = 8;
235 		var->green.offset = 8;
236 		var->green.length = 8;
237 		var->blue.offset = 16;
238 		var->blue.length = 8;
239 		var->transp.offset = 0;
240 		var->transp.length = 0;
241 		break;
242 	case 32:		/* RGBA 8888 */
243 		var->red.offset = 0;
244 		var->red.length = 8;
245 		var->green.offset = 8;
246 		var->green.length = 8;
247 		var->blue.offset = 16;
248 		var->blue.length = 8;
249 		var->transp.offset = 24;
250 		var->transp.length = 8;
251 		break;
252 	}
253 	var->red.msb_right = 0;
254 	var->green.msb_right = 0;
255 	var->blue.msb_right = 0;
256 	var->transp.msb_right = 0;
257 
258 	return 0;
259 }
260 
261 /* This routine actually sets the video mode. It's in here where we
262  * the hardware state info->par and fix which can be affected by the
263  * change in par. For this driver it doesn't do much.
264  */
265 static int mc68x328fb_set_par(struct fb_info *info)
266 {
267 	info->fix.line_length = get_line_length(info->var.xres_virtual,
268 						info->var.bits_per_pixel);
269 	return 0;
270 }
271 
272     /*
273      *  Set a single color register. The values supplied are already
274      *  rounded down to the hardware's capabilities (according to the
275      *  entries in the var structure). Return != 0 for invalid regno.
276      */
277 
278 static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
279 			 u_int transp, struct fb_info *info)
280 {
281 	if (regno >= 256)	/* no. of hw registers */
282 		return 1;
283 	/*
284 	 * Program hardware... do anything you want with transp
285 	 */
286 
287 	/* grayscale works only partially under directcolor */
288 	if (info->var.grayscale) {
289 		/* grayscale = 0.30*R + 0.59*G + 0.11*B */
290 		red = green = blue =
291 		    (red * 77 + green * 151 + blue * 28) >> 8;
292 	}
293 
294 	/* Directcolor:
295 	 *   var->{color}.offset contains start of bitfield
296 	 *   var->{color}.length contains length of bitfield
297 	 *   {hardwarespecific} contains width of RAMDAC
298 	 *   cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)
299 	 *   RAMDAC[X] is programmed to (red, green, blue)
300 	 *
301 	 * Pseudocolor:
302 	 *    uses offset = 0 && length = RAMDAC register width.
303 	 *    var->{color}.offset is 0
304 	 *    var->{color}.length contains width of DAC
305 	 *    cmap is not used
306 	 *    RAMDAC[X] is programmed to (red, green, blue)
307 	 * Truecolor:
308 	 *    does not use DAC. Usually 3 are present.
309 	 *    var->{color}.offset contains start of bitfield
310 	 *    var->{color}.length contains length of bitfield
311 	 *    cmap is programmed to (red << red.offset) | (green << green.offset) |
312 	 *                      (blue << blue.offset) | (transp << transp.offset)
313 	 *    RAMDAC does not exist
314 	 */
315 #define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
316 	switch (info->fix.visual) {
317 	case FB_VISUAL_TRUECOLOR:
318 	case FB_VISUAL_PSEUDOCOLOR:
319 		red = CNVT_TOHW(red, info->var.red.length);
320 		green = CNVT_TOHW(green, info->var.green.length);
321 		blue = CNVT_TOHW(blue, info->var.blue.length);
322 		transp = CNVT_TOHW(transp, info->var.transp.length);
323 		break;
324 	case FB_VISUAL_DIRECTCOLOR:
325 		red = CNVT_TOHW(red, 8);	/* expect 8 bit DAC */
326 		green = CNVT_TOHW(green, 8);
327 		blue = CNVT_TOHW(blue, 8);
328 		/* hey, there is bug in transp handling... */
329 		transp = CNVT_TOHW(transp, 8);
330 		break;
331 	}
332 #undef CNVT_TOHW
333 	/* Truecolor has hardware independent palette */
334 	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
335 		u32 v;
336 
337 		if (regno >= 16)
338 			return 1;
339 
340 		v = (red << info->var.red.offset) |
341 		    (green << info->var.green.offset) |
342 		    (blue << info->var.blue.offset) |
343 		    (transp << info->var.transp.offset);
344 		switch (info->var.bits_per_pixel) {
345 		case 8:
346 			break;
347 		case 16:
348 			((u32 *) (info->pseudo_palette))[regno] = v;
349 			break;
350 		case 24:
351 		case 32:
352 			((u32 *) (info->pseudo_palette))[regno] = v;
353 			break;
354 		}
355 		return 0;
356 	}
357 	return 0;
358 }
359 
360     /*
361      *  Pan or Wrap the Display
362      *
363      *  This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
364      */
365 
366 static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
367 			   struct fb_info *info)
368 {
369 	if (var->vmode & FB_VMODE_YWRAP) {
370 		if (var->yoffset < 0
371 		    || var->yoffset >= info->var.yres_virtual
372 		    || var->xoffset)
373 			return -EINVAL;
374 	} else {
375 		if (var->xoffset + info->var.xres > info->var.xres_virtual ||
376 		    var->yoffset + info->var.yres > info->var.yres_virtual)
377 			return -EINVAL;
378 	}
379 	info->var.xoffset = var->xoffset;
380 	info->var.yoffset = var->yoffset;
381 	if (var->vmode & FB_VMODE_YWRAP)
382 		info->var.vmode |= FB_VMODE_YWRAP;
383 	else
384 		info->var.vmode &= ~FB_VMODE_YWRAP;
385 	return 0;
386 }
387 
388     /*
389      *  Most drivers don't need their own mmap function
390      */
391 
392 static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
393 {
394 #ifndef MMU
395 	/* this is uClinux (no MMU) specific code */
396 
397 	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
398 	vma->vm_start = videomemory;
399 
400 	return 0;
401 #else
402 	return -EINVAL;
403 #endif
404 }
405 
406 int __init mc68x328fb_setup(char *options)
407 {
408 	if (!options || !*options)
409 		return 1;
410 	return 1;
411 }
412 
413     /*
414      *  Initialisation
415      */
416 
417 int __init mc68x328fb_init(void)
418 {
419 #ifndef MODULE
420 	char *option = NULL;
421 
422 	if (fb_get_options("68328fb", &option))
423 		return -ENODEV;
424 	mc68x328fb_setup(option);
425 #endif
426 	/*
427 	 *  initialize the default mode from the LCD controller registers
428 	 */
429 	mc68x328fb_default.xres = LXMAX;
430 	mc68x328fb_default.yres = LYMAX+1;
431 	mc68x328fb_default.xres_virtual = mc68x328fb_default.xres;
432 	mc68x328fb_default.yres_virtual = mc68x328fb_default.yres;
433 	mc68x328fb_default.bits_per_pixel = 1 + (LPICF & 0x01);
434 	videomemory = LSSA;
435 	videomemorysize = (mc68x328fb_default.xres_virtual+7) / 8 *
436 		mc68x328fb_default.yres_virtual * mc68x328fb_default.bits_per_pixel;
437 
438 	fb_info.screen_base = (void *)videomemory;
439 	fb_info.fbops = &mc68x328fb_ops;
440 	fb_info.var = mc68x328fb_default;
441 	fb_info.fix = mc68x328fb_fix;
442 	fb_info.fix.smem_start = videomemory;
443 	fb_info.fix.smem_len = videomemorysize;
444 	fb_info.fix.line_length =
445 		get_line_length(mc68x328fb_default.xres_virtual, mc68x328fb_default.bits_per_pixel);
446 	fb_info.fix.visual = (mc68x328fb_default.bits_per_pixel) == 1 ?
447 		FB_VISUAL_MONO10 : FB_VISUAL_PSEUDOCOLOR;
448 	if (fb_info.var.bits_per_pixel == 1) {
449 		fb_info.var.red.length = fb_info.var.green.length = fb_info.var.blue.length = 1;
450 		fb_info.var.red.offset = fb_info.var.green.offset = fb_info.var.blue.offset = 0;
451 	}
452 	fb_info.pseudo_palette = &mc68x328fb_pseudo_palette;
453 	fb_info.flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
454 
455 	if (fb_alloc_cmap(&fb_info.cmap, 256, 0))
456 		return -ENOMEM;
457 
458 	if (register_framebuffer(&fb_info) < 0) {
459 		fb_dealloc_cmap(&fb_info.cmap);
460 		return -EINVAL;
461 	}
462 
463 	fb_info(&fb_info, "%s frame buffer device\n", fb_info.fix.id);
464 	fb_info(&fb_info, "%dx%dx%d at 0x%08lx\n",
465 		mc68x328fb_default.xres_virtual,
466 		mc68x328fb_default.yres_virtual,
467 		1 << mc68x328fb_default.bits_per_pixel, videomemory);
468 
469 	return 0;
470 }
471 
472 module_init(mc68x328fb_init);
473 
474 #ifdef MODULE
475 
476 static void __exit mc68x328fb_cleanup(void)
477 {
478 	unregister_framebuffer(&fb_info);
479 	fb_dealloc_cmap(&fb_info.cmap);
480 }
481 
482 module_exit(mc68x328fb_cleanup);
483 
484 MODULE_LICENSE("GPL");
485 #endif				/* MODULE */
486