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
52static u_long videomemory;
53static u_long videomemorysize;
54
55static struct fb_info fb_info;
56static u32 mc68x328fb_pseudo_palette[16];
57
58static 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
75static 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     */
87static int mc68x328fb_check_var(struct fb_var_screeninfo *var,
88			 struct fb_info *info);
89static int mc68x328fb_set_par(struct fb_info *info);
90static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
91			 u_int transp, struct fb_info *info);
92static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
93			   struct fb_info *info);
94static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma);
95
96static const struct fb_ops mc68x328fb_ops = {
97	.owner		= THIS_MODULE,
98	.fb_check_var	= mc68x328fb_check_var,
99	.fb_set_par	= mc68x328fb_set_par,
100	.fb_setcolreg	= mc68x328fb_setcolreg,
101	.fb_pan_display	= mc68x328fb_pan_display,
102	.fb_fillrect	= cfb_fillrect,
103	.fb_copyarea	= cfb_copyarea,
104	.fb_imageblit	= cfb_imageblit,
105	.fb_mmap	= mc68x328fb_mmap,
106};
107
108    /*
109     *  Internal routines
110     */
111
112static u_long get_line_length(int xres_virtual, int bpp)
113{
114	u_long length;
115
116	length = xres_virtual * bpp;
117	length = (length + 31) & ~31;
118	length >>= 3;
119	return (length);
120}
121
122    /*
123     *  Setting the video mode has been split into two parts.
124     *  First part, xxxfb_check_var, must not write anything
125     *  to hardware, it should only verify and adjust var.
126     *  This means it doesn't alter par but it does use hardware
127     *  data from it to check this var.
128     */
129
130static int mc68x328fb_check_var(struct fb_var_screeninfo *var,
131			 struct fb_info *info)
132{
133	u_long line_length;
134
135	/*
136	 *  FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
137	 *  as FB_VMODE_SMOOTH_XPAN is only used internally
138	 */
139
140	if (var->vmode & FB_VMODE_CONUPDATE) {
141		var->vmode |= FB_VMODE_YWRAP;
142		var->xoffset = info->var.xoffset;
143		var->yoffset = info->var.yoffset;
144	}
145
146	/*
147	 *  Some very basic checks
148	 */
149	if (!var->xres)
150		var->xres = 1;
151	if (!var->yres)
152		var->yres = 1;
153	if (var->xres > var->xres_virtual)
154		var->xres_virtual = var->xres;
155	if (var->yres > var->yres_virtual)
156		var->yres_virtual = var->yres;
157	if (var->bits_per_pixel <= 1)
158		var->bits_per_pixel = 1;
159	else if (var->bits_per_pixel <= 8)
160		var->bits_per_pixel = 8;
161	else if (var->bits_per_pixel <= 16)
162		var->bits_per_pixel = 16;
163	else if (var->bits_per_pixel <= 24)
164		var->bits_per_pixel = 24;
165	else if (var->bits_per_pixel <= 32)
166		var->bits_per_pixel = 32;
167	else
168		return -EINVAL;
169
170	if (var->xres_virtual < var->xoffset + var->xres)
171		var->xres_virtual = var->xoffset + var->xres;
172	if (var->yres_virtual < var->yoffset + var->yres)
173		var->yres_virtual = var->yoffset + var->yres;
174
175	/*
176	 *  Memory limit
177	 */
178	line_length =
179	    get_line_length(var->xres_virtual, var->bits_per_pixel);
180	if (line_length * var->yres_virtual > videomemorysize)
181		return -ENOMEM;
182
183	/*
184	 * Now that we checked it we alter var. The reason being is that the video
185	 * mode passed in might not work but slight changes to it might make it
186	 * work. This way we let the user know what is acceptable.
187	 */
188	switch (var->bits_per_pixel) {
189	case 1:
190		var->red.offset = 0;
191		var->red.length = 1;
192		var->green.offset = 0;
193		var->green.length = 1;
194		var->blue.offset = 0;
195		var->blue.length = 1;
196		var->transp.offset = 0;
197		var->transp.length = 0;
198		break;
199	case 8:
200		var->red.offset = 0;
201		var->red.length = 8;
202		var->green.offset = 0;
203		var->green.length = 8;
204		var->blue.offset = 0;
205		var->blue.length = 8;
206		var->transp.offset = 0;
207		var->transp.length = 0;
208		break;
209	case 16:		/* RGBA 5551 */
210		if (var->transp.length) {
211			var->red.offset = 0;
212			var->red.length = 5;
213			var->green.offset = 5;
214			var->green.length = 5;
215			var->blue.offset = 10;
216			var->blue.length = 5;
217			var->transp.offset = 15;
218			var->transp.length = 1;
219		} else {	/* RGB 565 */
220			var->red.offset = 0;
221			var->red.length = 5;
222			var->green.offset = 5;
223			var->green.length = 6;
224			var->blue.offset = 11;
225			var->blue.length = 5;
226			var->transp.offset = 0;
227			var->transp.length = 0;
228		}
229		break;
230	case 24:		/* RGB 888 */
231		var->red.offset = 0;
232		var->red.length = 8;
233		var->green.offset = 8;
234		var->green.length = 8;
235		var->blue.offset = 16;
236		var->blue.length = 8;
237		var->transp.offset = 0;
238		var->transp.length = 0;
239		break;
240	case 32:		/* RGBA 8888 */
241		var->red.offset = 0;
242		var->red.length = 8;
243		var->green.offset = 8;
244		var->green.length = 8;
245		var->blue.offset = 16;
246		var->blue.length = 8;
247		var->transp.offset = 24;
248		var->transp.length = 8;
249		break;
250	}
251	var->red.msb_right = 0;
252	var->green.msb_right = 0;
253	var->blue.msb_right = 0;
254	var->transp.msb_right = 0;
255
256	return 0;
257}
258
259/* This routine actually sets the video mode. It's in here where we
260 * the hardware state info->par and fix which can be affected by the
261 * change in par. For this driver it doesn't do much.
262 */
263static int mc68x328fb_set_par(struct fb_info *info)
264{
265	info->fix.line_length = get_line_length(info->var.xres_virtual,
266						info->var.bits_per_pixel);
267	return 0;
268}
269
270    /*
271     *  Set a single color register. The values supplied are already
272     *  rounded down to the hardware's capabilities (according to the
273     *  entries in the var structure). Return != 0 for invalid regno.
274     */
275
276static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
277			 u_int transp, struct fb_info *info)
278{
279	if (regno >= 256)	/* no. of hw registers */
280		return 1;
281	/*
282	 * Program hardware... do anything you want with transp
283	 */
284
285	/* grayscale works only partially under directcolor */
286	if (info->var.grayscale) {
287		/* grayscale = 0.30*R + 0.59*G + 0.11*B */
288		red = green = blue =
289		    (red * 77 + green * 151 + blue * 28) >> 8;
290	}
291
292	/* Directcolor:
293	 *   var->{color}.offset contains start of bitfield
294	 *   var->{color}.length contains length of bitfield
295	 *   {hardwarespecific} contains width of RAMDAC
296	 *   cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)
297	 *   RAMDAC[X] is programmed to (red, green, blue)
298	 *
299	 * Pseudocolor:
300	 *    uses offset = 0 && length = RAMDAC register width.
301	 *    var->{color}.offset is 0
302	 *    var->{color}.length contains width of DAC
303	 *    cmap is not used
304	 *    RAMDAC[X] is programmed to (red, green, blue)
305	 * Truecolor:
306	 *    does not use DAC. Usually 3 are present.
307	 *    var->{color}.offset contains start of bitfield
308	 *    var->{color}.length contains length of bitfield
309	 *    cmap is programmed to (red << red.offset) | (green << green.offset) |
310	 *                      (blue << blue.offset) | (transp << transp.offset)
311	 *    RAMDAC does not exist
312	 */
313#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
314	switch (info->fix.visual) {
315	case FB_VISUAL_TRUECOLOR:
316	case FB_VISUAL_PSEUDOCOLOR:
317		red = CNVT_TOHW(red, info->var.red.length);
318		green = CNVT_TOHW(green, info->var.green.length);
319		blue = CNVT_TOHW(blue, info->var.blue.length);
320		transp = CNVT_TOHW(transp, info->var.transp.length);
321		break;
322	case FB_VISUAL_DIRECTCOLOR:
323		red = CNVT_TOHW(red, 8);	/* expect 8 bit DAC */
324		green = CNVT_TOHW(green, 8);
325		blue = CNVT_TOHW(blue, 8);
326		/* hey, there is bug in transp handling... */
327		transp = CNVT_TOHW(transp, 8);
328		break;
329	}
330#undef CNVT_TOHW
331	/* Truecolor has hardware independent palette */
332	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
333		u32 v;
334
335		if (regno >= 16)
336			return 1;
337
338		v = (red << info->var.red.offset) |
339		    (green << info->var.green.offset) |
340		    (blue << info->var.blue.offset) |
341		    (transp << info->var.transp.offset);
342		switch (info->var.bits_per_pixel) {
343		case 8:
344			break;
345		case 16:
346			((u32 *) (info->pseudo_palette))[regno] = v;
347			break;
348		case 24:
349		case 32:
350			((u32 *) (info->pseudo_palette))[regno] = v;
351			break;
352		}
353		return 0;
354	}
355	return 0;
356}
357
358    /*
359     *  Pan or Wrap the Display
360     *
361     *  This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
362     */
363
364static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
365			   struct fb_info *info)
366{
367	if (var->vmode & FB_VMODE_YWRAP) {
368		if (var->yoffset < 0
369		    || var->yoffset >= info->var.yres_virtual
370		    || var->xoffset)
371			return -EINVAL;
372	} else {
373		if (var->xoffset + info->var.xres > info->var.xres_virtual ||
374		    var->yoffset + info->var.yres > info->var.yres_virtual)
375			return -EINVAL;
376	}
377	info->var.xoffset = var->xoffset;
378	info->var.yoffset = var->yoffset;
379	if (var->vmode & FB_VMODE_YWRAP)
380		info->var.vmode |= FB_VMODE_YWRAP;
381	else
382		info->var.vmode &= ~FB_VMODE_YWRAP;
383	return 0;
384}
385
386    /*
387     *  Most drivers don't need their own mmap function
388     */
389
390static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
391{
392#ifndef MMU
393	/* this is uClinux (no MMU) specific code */
394
395	vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
396	vma->vm_start = videomemory;
397
398	return 0;
399#else
400	return -EINVAL;
401#endif
402}
403
404static int __init mc68x328fb_setup(char *options)
405{
406	if (!options || !*options)
407		return 1;
408	return 1;
409}
410
411    /*
412     *  Initialisation
413     */
414
415static int __init mc68x328fb_init(void)
416{
417#ifndef MODULE
418	char *option = NULL;
419
420	if (fb_get_options("68328fb", &option))
421		return -ENODEV;
422	mc68x328fb_setup(option);
423#endif
424	/*
425	 *  initialize the default mode from the LCD controller registers
426	 */
427	mc68x328fb_default.xres = LXMAX;
428	mc68x328fb_default.yres = LYMAX+1;
429	mc68x328fb_default.xres_virtual = mc68x328fb_default.xres;
430	mc68x328fb_default.yres_virtual = mc68x328fb_default.yres;
431	mc68x328fb_default.bits_per_pixel = 1 + (LPICF & 0x01);
432	videomemory = LSSA;
433	videomemorysize = (mc68x328fb_default.xres_virtual+7) / 8 *
434		mc68x328fb_default.yres_virtual * mc68x328fb_default.bits_per_pixel;
435
436	fb_info.screen_base = (void *)videomemory;
437	fb_info.fbops = &mc68x328fb_ops;
438	fb_info.var = mc68x328fb_default;
439	fb_info.fix = mc68x328fb_fix;
440	fb_info.fix.smem_start = videomemory;
441	fb_info.fix.smem_len = videomemorysize;
442	fb_info.fix.line_length =
443		get_line_length(mc68x328fb_default.xres_virtual, mc68x328fb_default.bits_per_pixel);
444	fb_info.fix.visual = (mc68x328fb_default.bits_per_pixel) == 1 ?
445		FB_VISUAL_MONO10 : FB_VISUAL_PSEUDOCOLOR;
446	if (fb_info.var.bits_per_pixel == 1) {
447		fb_info.var.red.length = fb_info.var.green.length = fb_info.var.blue.length = 1;
448		fb_info.var.red.offset = fb_info.var.green.offset = fb_info.var.blue.offset = 0;
449	}
450	fb_info.pseudo_palette = &mc68x328fb_pseudo_palette;
451	fb_info.flags = FBINFO_HWACCEL_YPAN;
452
453	if (fb_alloc_cmap(&fb_info.cmap, 256, 0))
454		return -ENOMEM;
455
456	if (register_framebuffer(&fb_info) < 0) {
457		fb_dealloc_cmap(&fb_info.cmap);
458		return -EINVAL;
459	}
460
461	fb_info(&fb_info, "%s frame buffer device\n", fb_info.fix.id);
462	fb_info(&fb_info, "%dx%dx%d at 0x%08lx\n",
463		mc68x328fb_default.xres_virtual,
464		mc68x328fb_default.yres_virtual,
465		1 << mc68x328fb_default.bits_per_pixel, videomemory);
466
467	return 0;
468}
469
470module_init(mc68x328fb_init);
471
472#ifdef MODULE
473
474static void __exit mc68x328fb_cleanup(void)
475{
476	unregister_framebuffer(&fb_info);
477	fb_dealloc_cmap(&fb_info.cmap);
478}
479
480module_exit(mc68x328fb_cleanup);
481
482MODULE_LICENSE("GPL");
483#endif				/* MODULE */
484