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