xref: /openbmc/linux/drivers/video/fbdev/maxinefb.c (revision 3ddc8b84)
1 /*
2  *      linux/drivers/video/maxinefb.c
3  *
4  *	DECstation 5000/xx onboard framebuffer support ... derived from:
5  *	"HP300 Topcat framebuffer support (derived from macfb of all things)
6  *	Phil Blundell <philb@gnu.org> 1998", the original code can be
7  *      found in the file hpfb.c in the same directory.
8  *
9  *      DECstation related code Copyright (C) 1999,2000,2001 by
10  *      Michael Engel <engel@unix-ag.org> and
11  *      Karsten Merker <merker@linuxtag.org>.
12  *      This file is subject to the terms and conditions of the GNU General
13  *      Public License.  See the file COPYING in the main directory of this
14  *      archive for more details.
15  *
16  */
17 
18 /*
19  * Changes:
20  * 2001/01/27 removed debugging and testing code, fixed fb_ops
21  *            initialization which had caused a crash before,
22  *            general cleanup, first official release (KM)
23  *
24  */
25 
26 #include <linux/module.h>
27 #include <linux/kernel.h>
28 #include <linux/errno.h>
29 #include <linux/string.h>
30 #include <linux/mm.h>
31 #include <linux/delay.h>
32 #include <linux/init.h>
33 #include <linux/fb.h>
34 #include <video/maxinefb.h>
35 
36 /* bootinfo.h defines the machine type values, needed when checking */
37 /* whether are really running on a maxine, KM                       */
38 #include <asm/bootinfo.h>
39 
40 static struct fb_info fb_info;
41 
42 static const struct fb_var_screeninfo maxinefb_defined = {
43 	.xres =		1024,
44 	.yres =		768,
45 	.xres_virtual =	1024,
46 	.yres_virtual =	768,
47 	.bits_per_pixel =8,
48 	.activate =	FB_ACTIVATE_NOW,
49 	.height =	-1,
50 	.width =	-1,
51 	.vmode =	FB_VMODE_NONINTERLACED,
52 };
53 
54 static struct fb_fix_screeninfo maxinefb_fix __initdata = {
55 	.id =		"Maxine",
56 	.smem_len =	(1024*768),
57 	.type =		FB_TYPE_PACKED_PIXELS,
58 	.visual =	FB_VISUAL_PSEUDOCOLOR,
59 	.line_length =	1024,
60 };
61 
62 /* Handle the funny Inmos RamDAC/video controller ... */
63 
64 void maxinefb_ims332_write_register(int regno, register unsigned int val)
65 {
66 	register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
67 	unsigned char *wptr;
68 
69 	wptr = regs + 0xa0000 + (regno << 4);
70 	*((volatile unsigned int *) (regs)) = (val >> 8) & 0xff00;
71 	*((volatile unsigned short *) (wptr)) = val;
72 }
73 
74 unsigned int maxinefb_ims332_read_register(int regno)
75 {
76 	register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
77 	unsigned char *rptr;
78 	register unsigned int j, k;
79 
80 	rptr = regs + 0x80000 + (regno << 4);
81 	j = *((volatile unsigned short *) rptr);
82 	k = *((volatile unsigned short *) regs);
83 
84 	return (j & 0xffff) | ((k & 0xff00) << 8);
85 }
86 
87 /* Set the palette */
88 static int maxinefb_setcolreg(unsigned regno, unsigned red, unsigned green,
89 			      unsigned blue, unsigned transp, struct fb_info *info)
90 {
91 	/* value to be written into the palette reg. */
92 	unsigned long hw_colorvalue = 0;
93 
94 	if (regno > 255)
95 		return 1;
96 
97 	red   >>= 8;    /* The cmap fields are 16 bits    */
98 	green >>= 8;    /* wide, but the harware colormap */
99 	blue  >>= 8;    /* registers are only 8 bits wide */
100 
101 	hw_colorvalue = (blue << 16) + (green << 8) + (red);
102 
103 	maxinefb_ims332_write_register(IMS332_REG_COLOR_PALETTE + regno,
104 				       hw_colorvalue);
105 	return 0;
106 }
107 
108 static const struct fb_ops maxinefb_ops = {
109 	.owner		= THIS_MODULE,
110 	FB_DEFAULT_IOMEM_OPS,
111 	.fb_setcolreg	= maxinefb_setcolreg,
112 };
113 
114 int __init maxinefb_init(void)
115 {
116 	unsigned long fboff;
117 	unsigned long fb_start;
118 	int i;
119 
120 	if (fb_get_options("maxinefb", NULL))
121 		return -ENODEV;
122 
123 	/* Validate we're on the proper machine type */
124 	if (mips_machtype != MACH_DS5000_XX) {
125 		return -EINVAL;
126 	}
127 
128 	printk(KERN_INFO "Maxinefb: Personal DECstation detected\n");
129 	printk(KERN_INFO "Maxinefb: initializing onboard framebuffer\n");
130 
131 	/* Framebuffer display memory base address */
132 	fb_start = DS5000_xx_ONBOARD_FBMEM_START;
133 
134 	/* Clear screen */
135 	for (fboff = fb_start; fboff < fb_start + 0x1ffff; fboff++)
136 		*(volatile unsigned char *)fboff = 0x0;
137 
138 	maxinefb_fix.smem_start = fb_start;
139 
140 	/* erase hardware cursor */
141 	for (i = 0; i < 512; i++) {
142 		maxinefb_ims332_write_register(IMS332_REG_CURSOR_RAM + i,
143 					       0);
144 		/*
145 		   if (i&0x8 == 0)
146 		   maxinefb_ims332_write_register (IMS332_REG_CURSOR_RAM + i, 0x0f);
147 		   else
148 		   maxinefb_ims332_write_register (IMS332_REG_CURSOR_RAM + i, 0xf0);
149 		 */
150 	}
151 
152 	fb_info.fbops = &maxinefb_ops;
153 	fb_info.screen_base = (char *)maxinefb_fix.smem_start;
154 	fb_info.var = maxinefb_defined;
155 	fb_info.fix = maxinefb_fix;
156 
157 	fb_alloc_cmap(&fb_info.cmap, 256, 0);
158 
159 	if (register_framebuffer(&fb_info) < 0)
160 		return 1;
161 	return 0;
162 }
163 
164 static void __exit maxinefb_exit(void)
165 {
166 	unregister_framebuffer(&fb_info);
167 }
168 
169 #ifdef MODULE
170 MODULE_LICENSE("GPL");
171 #endif
172 module_init(maxinefb_init);
173 module_exit(maxinefb_exit);
174 
175