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 <asm/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 struct fb_fix_screeninfo mc68x328fb_fix __initdata = {
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     */
87int mc68x328fb_init(void);
88int mc68x328fb_setup(char *);
89
90static int mc68x328fb_check_var(struct fb_var_screeninfo *var,
91			 struct fb_info *info);
92static int mc68x328fb_set_par(struct fb_info *info);
93static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
94			 u_int transp, struct fb_info *info);
95static int mc68x328fb_pan_display(struct fb_var_screeninfo *var,
96			   struct fb_info *info);
97static int mc68x328fb_mmap(struct fb_info *info, struct vm_area_struct *vma);
98
99static 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
114static 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
132static 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 */
265static 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
278static 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
366static 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
392static 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
406int __init mc68x328fb_setup(char *options)
407{
408#if 0
409	char *this_opt;
410#endif
411
412	if (!options || !*options)
413		return 1;
414#if 0
415	while ((this_opt = strsep(&options, ",")) != NULL) {
416		if (!*this_opt)
417			continue;
418		if (!strncmp(this_opt, "disable", 7))
419			mc68x328fb_enable = 0;
420	}
421#endif
422	return 1;
423}
424
425    /*
426     *  Initialisation
427     */
428
429int __init mc68x328fb_init(void)
430{
431#ifndef MODULE
432	char *option = NULL;
433
434	if (fb_get_options("68328fb", &option))
435		return -ENODEV;
436	mc68x328fb_setup(option);
437#endif
438	/*
439	 *  initialize the default mode from the LCD controller registers
440	 */
441	mc68x328fb_default.xres = LXMAX;
442	mc68x328fb_default.yres = LYMAX+1;
443	mc68x328fb_default.xres_virtual = mc68x328fb_default.xres;
444	mc68x328fb_default.yres_virtual = mc68x328fb_default.yres;
445	mc68x328fb_default.bits_per_pixel = 1 + (LPICF & 0x01);
446	videomemory = LSSA;
447	videomemorysize = (mc68x328fb_default.xres_virtual+7) / 8 *
448		mc68x328fb_default.yres_virtual * mc68x328fb_default.bits_per_pixel;
449
450	fb_info.screen_base = (void *)videomemory;
451	fb_info.fbops = &mc68x328fb_ops;
452	fb_info.var = mc68x328fb_default;
453	fb_info.fix = mc68x328fb_fix;
454	fb_info.fix.smem_start = videomemory;
455	fb_info.fix.smem_len = videomemorysize;
456	fb_info.fix.line_length =
457		get_line_length(mc68x328fb_default.xres_virtual, mc68x328fb_default.bits_per_pixel);
458	fb_info.fix.visual = (mc68x328fb_default.bits_per_pixel) == 1 ?
459		FB_VISUAL_MONO10 : FB_VISUAL_PSEUDOCOLOR;
460	if (fb_info.var.bits_per_pixel == 1) {
461		fb_info.var.red.length = fb_info.var.green.length = fb_info.var.blue.length = 1;
462		fb_info.var.red.offset = fb_info.var.green.offset = fb_info.var.blue.offset = 0;
463	}
464	fb_info.pseudo_palette = &mc68x328fb_pseudo_palette;
465	fb_info.flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
466
467	if (fb_alloc_cmap(&fb_info.cmap, 256, 0))
468		return -ENOMEM;
469
470	if (register_framebuffer(&fb_info) < 0) {
471		fb_dealloc_cmap(&fb_info.cmap);
472		return -EINVAL;
473	}
474
475	fb_info(&fb_info, "%s frame buffer device\n", fb_info.fix.id);
476	fb_info(&fb_info, "%dx%dx%d at 0x%08lx\n",
477		mc68x328fb_default.xres_virtual,
478		mc68x328fb_default.yres_virtual,
479		1 << mc68x328fb_default.bits_per_pixel, videomemory);
480
481	return 0;
482}
483
484module_init(mc68x328fb_init);
485
486#ifdef MODULE
487
488static void __exit mc68x328fb_cleanup(void)
489{
490	unregister_framebuffer(&fb_info);
491	fb_dealloc_cmap(&fb_info.cmap);
492}
493
494module_exit(mc68x328fb_cleanup);
495
496MODULE_LICENSE("GPL");
497#endif				/* MODULE */
498