xref: /openbmc/linux/drivers/video/fbdev/fm2fb.c (revision 210bbb71)
1 /*
2  *  linux/drivers/video/fm2fb.c -- BSC FrameMaster II/Rainbow II frame buffer
3  *				   device
4  *
5  *	Copyright (C) 1998 Steffen A. Mork (linux-dev@morknet.de)
6  *	Copyright (C) 1999 Geert Uytterhoeven
7  *
8  *  Written for 2.0.x by Steffen A. Mork
9  *  Ported to 2.1.x by Geert Uytterhoeven
10  *  Ported to new api by James Simmons
11  *
12  *  This file is subject to the terms and conditions of the GNU General Public
13  *  License. See the file COPYING in the main directory of this archive for
14  *  more details.
15  */
16 
17 #include <linux/module.h>
18 #include <linux/mm.h>
19 #include <linux/fb.h>
20 #include <linux/init.h>
21 #include <linux/zorro.h>
22 #include <asm/io.h>
23 
24 /*
25  *	Some technical notes:
26  *
27  *	The BSC FrameMaster II (or Rainbow II) is a simple very dumb
28  *	frame buffer which allows to display 24 bit true color images.
29  *	Each pixel is 32 bit width so it's very easy to maintain the
30  *	frame buffer. One long word has the following layout:
31  *	AARRGGBB which means: AA the alpha channel byte, RR the red
32  *	channel, GG the green channel and BB the blue channel.
33  *
34  *	The FrameMaster II supports the following video modes.
35  *	- PAL/NTSC
36  *	- interlaced/non interlaced
37  *	- composite sync/sync/sync over green
38  *
39  *	The resolution is to the following both ones:
40  *	- 768x576 (PAL)
41  *	- 768x480 (NTSC)
42  *
43  *	This means that pixel access per line is fixed due to the
44  *	fixed line width. In case of maximal resolution the frame
45  *	buffer needs an amount of memory of 1.769.472 bytes which
46  *	is near to 2 MByte (the allocated address space of Zorro2).
47  *	The memory is channel interleaved. That means every channel
48  *	owns four VRAMs. Unfortunately most FrameMasters II are
49  *	not assembled with memory for the alpha channel. In this
50  *	case it could be possible to add the frame buffer into the
51  *	normal memory pool.
52  *
53  *	At relative address 0x1ffff8 of the frame buffers base address
54  *	there exists a control register with the number of
55  *	four control bits. They have the following meaning:
56  *	bit value meaning
57  *
58  *	 0    1   0=interlaced/1=non interlaced
59  *	 1    2   0=video out disabled/1=video out enabled
60  *	 2    4   0=normal mode as jumpered via JP8/1=complement mode
61  *	 3    8   0=read  onboard ROM/1 normal operation (required)
62  *
63  *	As mentioned above there are several jumper. I think there
64  *	is not very much information about the FrameMaster II in
65  *	the world so I add these information for completeness.
66  *
67  *	JP1  interlace selection (1-2 non interlaced/2-3 interlaced)
68  *	JP2  wait state creation (leave as is!)
69  *	JP3  wait state creation (leave as is!)
70  *	JP4  modulate composite sync on green output (1-2 composite
71  *	     sync on green channel/2-3 normal composite sync)
72  *	JP5  create test signal, shorting this jumper will create
73  *	     a white screen
74  *	JP6  sync creation (1-2 composite sync/2-3 H-sync output)
75  *	JP8  video mode (1-2 PAL/2-3 NTSC)
76  *
77  *	With the following jumpering table you can connect the
78  *	FrameMaster II to a normal TV via SCART connector:
79  *	JP1:  2-3
80  *	JP4:  2-3
81  *	JP6:  2-3
82  *	JP8:  1-2 (means PAL for Europe)
83  *
84  *	NOTE:
85  *	There is no other possibility to change the video timings
86  *	except the interlaced/non interlaced, sync control and the
87  *	video mode PAL (50 Hz)/NTSC (60 Hz). Inside this
88  *	FrameMaster II driver are assumed values to avoid anomalies
89  *	to a future X server. Except the pixel clock is really
90  *	constant at 30 MHz.
91  *
92  *	9 pin female video connector:
93  *
94  *	1  analog red 0.7 Vss
95  *	2  analog green 0.7 Vss
96  *	3  analog blue 0.7 Vss
97  *	4  H-sync TTL
98  *	5  V-sync TTL
99  *	6  ground
100  *	7  ground
101  *	8  ground
102  *	9  ground
103  *
104  *	Some performance notes:
105  *	The FrameMaster II was not designed to display a console
106  *	this driver would do! It was designed to display still true
107  *	color images. Imagine: When scroll up a text line there
108  *	must copied ca. 1.7 MBytes to another place inside this
109  *	frame buffer. This means 1.7 MByte read and 1.7 MByte write
110  *	over the slow 16 bit wide Zorro2 bus! A scroll of one
111  *	line needs 1 second so do not expect to much from this
112  *	driver - he is at the limit!
113  *
114  */
115 
116 /*
117  *	definitions
118  */
119 
120 #define FRAMEMASTER_SIZE	0x200000
121 #define FRAMEMASTER_REG		0x1ffff8
122 
123 #define FRAMEMASTER_NOLACE	1
124 #define FRAMEMASTER_ENABLE	2
125 #define FRAMEMASTER_COMPL	4
126 #define FRAMEMASTER_ROM		8
127 
128 static volatile unsigned char *fm2fb_reg;
129 
130 static struct fb_fix_screeninfo fb_fix = {
131 	.smem_len =	FRAMEMASTER_REG,
132 	.type =		FB_TYPE_PACKED_PIXELS,
133 	.visual =	FB_VISUAL_TRUECOLOR,
134 	.line_length =	(768 << 2),
135 	.mmio_len =	(8),
136 	.accel =	FB_ACCEL_NONE,
137 };
138 
139 static int fm2fb_mode = -1;
140 
141 #define FM2FB_MODE_PAL	0
142 #define FM2FB_MODE_NTSC	1
143 
144 static struct fb_var_screeninfo fb_var_modes[] = {
145     {
146 	/* 768 x 576, 32 bpp (PAL) */
147 	768, 576, 768, 576, 0, 0, 32, 0,
148 	{ 16, 8, 0 }, { 8, 8, 0 }, { 0, 8, 0 }, { 24, 8, 0 },
149 	0, FB_ACTIVATE_NOW, -1, -1, FB_ACCEL_NONE,
150 	33333, 10, 102, 10, 5, 80, 34, FB_SYNC_COMP_HIGH_ACT, 0
151     }, {
152 	/* 768 x 480, 32 bpp (NTSC - not supported yet */
153 	768, 480, 768, 480, 0, 0, 32, 0,
154 	{ 16, 8, 0 }, { 8, 8, 0 }, { 0, 8, 0 }, { 24, 8, 0 },
155 	0, FB_ACTIVATE_NOW, -1, -1, FB_ACCEL_NONE,
156 	33333, 10, 102, 10, 5, 80, 34, FB_SYNC_COMP_HIGH_ACT, 0
157     }
158 };
159 
160     /*
161      *  Interface used by the world
162      */
163 
164 static int fm2fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
165                            u_int transp, struct fb_info *info);
166 static int fm2fb_blank(int blank, struct fb_info *info);
167 
168 static const struct fb_ops fm2fb_ops = {
169 	.owner		= THIS_MODULE,
170 	FB_DEFAULT_IOMEM_OPS,
171 	.fb_setcolreg	= fm2fb_setcolreg,
172 	.fb_blank	= fm2fb_blank,
173 };
174 
175     /*
176      *  Blank the display.
177      */
fm2fb_blank(int blank,struct fb_info * info)178 static int fm2fb_blank(int blank, struct fb_info *info)
179 {
180 	unsigned char t = FRAMEMASTER_ROM;
181 
182 	if (!blank)
183 		t |= FRAMEMASTER_ENABLE | FRAMEMASTER_NOLACE;
184 	fm2fb_reg[0] = t;
185 	return 0;
186 }
187 
188     /*
189      *  Set a single color register. The values supplied are already
190      *  rounded down to the hardware's capabilities (according to the
191      *  entries in the var structure). Return != 0 for invalid regno.
192      */
fm2fb_setcolreg(u_int regno,u_int red,u_int green,u_int blue,u_int transp,struct fb_info * info)193 static int fm2fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
194                          u_int transp, struct fb_info *info)
195 {
196 	if (regno < 16) {
197 		red >>= 8;
198 		green >>= 8;
199 		blue >>= 8;
200 
201 		((u32*)(info->pseudo_palette))[regno] = (red << 16) |
202 			(green << 8) | blue;
203 	}
204 
205 	return 0;
206 }
207 
208     /*
209      *  Initialisation
210      */
211 
212 static int fm2fb_probe(struct zorro_dev *z, const struct zorro_device_id *id);
213 
214 static const struct zorro_device_id fm2fb_devices[] = {
215 	{ ZORRO_PROD_BSC_FRAMEMASTER_II },
216 	{ ZORRO_PROD_HELFRICH_RAINBOW_II },
217 	{ 0 }
218 };
219 MODULE_DEVICE_TABLE(zorro, fm2fb_devices);
220 
221 static struct zorro_driver fm2fb_driver = {
222 	.name		= "fm2fb",
223 	.id_table	= fm2fb_devices,
224 	.probe		= fm2fb_probe,
225 };
226 
fm2fb_probe(struct zorro_dev * z,const struct zorro_device_id * id)227 static int fm2fb_probe(struct zorro_dev *z, const struct zorro_device_id *id)
228 {
229 	struct fb_info *info;
230 	unsigned long *ptr;
231 	int is_fm;
232 	int x, y;
233 
234 	is_fm = z->id == ZORRO_PROD_BSC_FRAMEMASTER_II;
235 
236 	if (!zorro_request_device(z,"fm2fb"))
237 		return -ENXIO;
238 
239 	info = framebuffer_alloc(16 * sizeof(u32), &z->dev);
240 	if (!info) {
241 		zorro_release_device(z);
242 		return -ENOMEM;
243 	}
244 
245 	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
246 		framebuffer_release(info);
247 		zorro_release_device(z);
248 		return -ENOMEM;
249 	}
250 
251 	/* assigning memory to kernel space */
252 	fb_fix.smem_start = zorro_resource_start(z);
253 	info->screen_base = ioremap(fb_fix.smem_start, FRAMEMASTER_SIZE);
254 	fb_fix.mmio_start = fb_fix.smem_start + FRAMEMASTER_REG;
255 	fm2fb_reg  = (unsigned char *)(info->screen_base+FRAMEMASTER_REG);
256 
257 	strcpy(fb_fix.id, is_fm ? "FrameMaster II" : "Rainbow II");
258 
259 	/* make EBU color bars on display */
260 	ptr = (unsigned long *)fb_fix.smem_start;
261 	for (y = 0; y < 576; y++) {
262 		for (x = 0; x < 96; x++) *ptr++ = 0xffffff;/* white */
263 		for (x = 0; x < 96; x++) *ptr++ = 0xffff00;/* yellow */
264 		for (x = 0; x < 96; x++) *ptr++ = 0x00ffff;/* cyan */
265 		for (x = 0; x < 96; x++) *ptr++ = 0x00ff00;/* green */
266 		for (x = 0; x < 96; x++) *ptr++ = 0xff00ff;/* magenta */
267 		for (x = 0; x < 96; x++) *ptr++ = 0xff0000;/* red */
268 		for (x = 0; x < 96; x++) *ptr++ = 0x0000ff;/* blue */
269 		for (x = 0; x < 96; x++) *ptr++ = 0x000000;/* black */
270 	}
271 	fm2fb_blank(0, info);
272 
273 	if (fm2fb_mode == -1)
274 		fm2fb_mode = FM2FB_MODE_PAL;
275 
276 	info->fbops = &fm2fb_ops;
277 	info->var = fb_var_modes[fm2fb_mode];
278 	info->pseudo_palette = info->par;
279 	info->par = NULL;
280 	info->fix = fb_fix;
281 
282 	if (register_framebuffer(info) < 0) {
283 		fb_dealloc_cmap(&info->cmap);
284 		iounmap(info->screen_base);
285 		framebuffer_release(info);
286 		zorro_release_device(z);
287 		return -EINVAL;
288 	}
289 	fb_info(info, "%s frame buffer device\n", fb_fix.id);
290 	return 0;
291 }
292 
fm2fb_setup(char * options)293 static int __init fm2fb_setup(char *options)
294 {
295 	char *this_opt;
296 
297 	if (!options || !*options)
298 		return 0;
299 
300 	while ((this_opt = strsep(&options, ",")) != NULL) {
301 		if (!strncmp(this_opt, "pal", 3))
302 			fm2fb_mode = FM2FB_MODE_PAL;
303 		else if (!strncmp(this_opt, "ntsc", 4))
304 			fm2fb_mode = FM2FB_MODE_NTSC;
305 	}
306 	return 0;
307 }
308 
fm2fb_init(void)309 static int __init fm2fb_init(void)
310 {
311 	char *option = NULL;
312 
313 	if (fb_get_options("fm2fb", &option))
314 		return -ENODEV;
315 	fm2fb_setup(option);
316 	return zorro_register_driver(&fm2fb_driver);
317 }
318 
319 module_init(fm2fb_init);
320 MODULE_LICENSE("GPL");
321