xref: /openbmc/linux/drivers/video/fbdev/pmag-ba-fb.c (revision 51840aaa)
1 /*
2  *	linux/drivers/video/pmag-ba-fb.c
3  *
4  *	PMAG-BA TURBOchannel Color Frame Buffer (CFB) card support,
5  *	derived from:
6  *	"HP300 Topcat framebuffer support (derived from macfb of all things)
7  *	Phil Blundell <philb@gnu.org> 1998", the original code can be
8  *	found in the file hpfb.c in the same directory.
9  *
10  *	Based on digital document:
11  * 	"PMAG-BA TURBOchannel Color Frame Buffer
12  *	 Functional Specification", Revision 1.2, August 27, 1990
13  *
14  *	DECstation related code Copyright (C) 1999, 2000, 2001 by
15  *	Michael Engel <engel@unix-ag.org>,
16  *	Karsten Merker <merker@linuxtag.org> and
17  *	Harald Koerfgen.
18  *	Copyright (c) 2005, 2006  Maciej W. Rozycki
19  *	Copyright (c) 2005  James Simmons
20  *
21  *	This file is subject to the terms and conditions of the GNU General
22  *	Public License.  See the file COPYING in the main directory of this
23  *	archive for more details.
24  */
25 
26 #include <linux/compiler.h>
27 #include <linux/errno.h>
28 #include <linux/fb.h>
29 #include <linux/init.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/tc.h>
33 #include <linux/types.h>
34 
35 #include <asm/io.h>
36 
37 #include <video/pmag-ba-fb.h>
38 
39 
40 struct pmagbafb_par {
41 	volatile void __iomem *mmio;
42 	volatile u32 __iomem *dac;
43 };
44 
45 
46 static const struct fb_var_screeninfo pmagbafb_defined = {
47 	.xres		= 1024,
48 	.yres		= 864,
49 	.xres_virtual	= 1024,
50 	.yres_virtual	= 864,
51 	.bits_per_pixel	= 8,
52 	.red.length	= 8,
53 	.green.length	= 8,
54 	.blue.length	= 8,
55 	.activate	= FB_ACTIVATE_NOW,
56 	.height		= -1,
57 	.width		= -1,
58 	.accel_flags	= FB_ACCEL_NONE,
59 	.pixclock	= 14452,
60 	.left_margin	= 116,
61 	.right_margin	= 12,
62 	.upper_margin	= 34,
63 	.lower_margin	= 0,
64 	.hsync_len	= 128,
65 	.vsync_len	= 3,
66 	.sync		= FB_SYNC_ON_GREEN,
67 	.vmode		= FB_VMODE_NONINTERLACED,
68 };
69 
70 static const struct fb_fix_screeninfo pmagbafb_fix = {
71 	.id		= "PMAG-BA",
72 	.smem_len	= (1024 * 1024),
73 	.type		= FB_TYPE_PACKED_PIXELS,
74 	.visual		= FB_VISUAL_PSEUDOCOLOR,
75 	.line_length	= 1024,
76 	.mmio_len	= PMAG_BA_SIZE - PMAG_BA_BT459,
77 };
78 
79 
dac_write(struct pmagbafb_par * par,unsigned int reg,u8 v)80 static inline void dac_write(struct pmagbafb_par *par, unsigned int reg, u8 v)
81 {
82 	writeb(v, par->dac + reg / 4);
83 }
84 
dac_read(struct pmagbafb_par * par,unsigned int reg)85 static inline u8 dac_read(struct pmagbafb_par *par, unsigned int reg)
86 {
87 	return readb(par->dac + reg / 4);
88 }
89 
90 
91 /*
92  * Set the palette.
93  */
pmagbafb_setcolreg(unsigned int regno,unsigned int red,unsigned int green,unsigned int blue,unsigned int transp,struct fb_info * info)94 static int pmagbafb_setcolreg(unsigned int regno, unsigned int red,
95 			      unsigned int green, unsigned int blue,
96 			      unsigned int transp, struct fb_info *info)
97 {
98 	struct pmagbafb_par *par = info->par;
99 
100 	if (regno >= info->cmap.len)
101 		return 1;
102 
103 	red   >>= 8;	/* The cmap fields are 16 bits    */
104 	green >>= 8;	/* wide, but the hardware colormap */
105 	blue  >>= 8;	/* registers are only 8 bits wide */
106 
107 	mb();
108 	dac_write(par, BT459_ADDR_LO, regno);
109 	dac_write(par, BT459_ADDR_HI, 0x00);
110 	wmb();
111 	dac_write(par, BT459_CMAP, red);
112 	wmb();
113 	dac_write(par, BT459_CMAP, green);
114 	wmb();
115 	dac_write(par, BT459_CMAP, blue);
116 
117 	return 0;
118 }
119 
120 static const struct fb_ops pmagbafb_ops = {
121 	.owner		= THIS_MODULE,
122 	FB_DEFAULT_IOMEM_OPS,
123 	.fb_setcolreg	= pmagbafb_setcolreg,
124 };
125 
126 
127 /*
128  * Turn the hardware cursor off.
129  */
pmagbafb_erase_cursor(struct fb_info * info)130 static void pmagbafb_erase_cursor(struct fb_info *info)
131 {
132 	struct pmagbafb_par *par = info->par;
133 
134 	mb();
135 	dac_write(par, BT459_ADDR_LO, 0x00);
136 	dac_write(par, BT459_ADDR_HI, 0x03);
137 	wmb();
138 	dac_write(par, BT459_DATA, 0x00);
139 }
140 
141 
pmagbafb_probe(struct device * dev)142 static int pmagbafb_probe(struct device *dev)
143 {
144 	struct tc_dev *tdev = to_tc_dev(dev);
145 	resource_size_t start, len;
146 	struct fb_info *info;
147 	struct pmagbafb_par *par;
148 	int err;
149 
150 	info = framebuffer_alloc(sizeof(struct pmagbafb_par), dev);
151 	if (!info)
152 		return -ENOMEM;
153 
154 	par = info->par;
155 	dev_set_drvdata(dev, info);
156 
157 	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
158 		printk(KERN_ERR "%s: Cannot allocate color map\n",
159 		       dev_name(dev));
160 		err = -ENOMEM;
161 		goto err_alloc;
162 	}
163 
164 	info->fbops = &pmagbafb_ops;
165 	info->fix = pmagbafb_fix;
166 	info->var = pmagbafb_defined;
167 
168 	/* Request the I/O MEM resource.  */
169 	start = tdev->resource.start;
170 	len = tdev->resource.end - start + 1;
171 	if (!request_mem_region(start, len, dev_name(dev))) {
172 		printk(KERN_ERR "%s: Cannot reserve FB region\n",
173 		       dev_name(dev));
174 		err = -EBUSY;
175 		goto err_cmap;
176 	}
177 
178 	/* MMIO mapping setup.  */
179 	info->fix.mmio_start = start;
180 	par->mmio = ioremap(info->fix.mmio_start, info->fix.mmio_len);
181 	if (!par->mmio) {
182 		printk(KERN_ERR "%s: Cannot map MMIO\n", dev_name(dev));
183 		err = -ENOMEM;
184 		goto err_resource;
185 	}
186 	par->dac = par->mmio + PMAG_BA_BT459;
187 
188 	/* Frame buffer mapping setup.  */
189 	info->fix.smem_start = start + PMAG_BA_FBMEM;
190 	info->screen_base = ioremap(info->fix.smem_start,
191 					    info->fix.smem_len);
192 	if (!info->screen_base) {
193 		printk(KERN_ERR "%s: Cannot map FB\n", dev_name(dev));
194 		err = -ENOMEM;
195 		goto err_mmio_map;
196 	}
197 	info->screen_size = info->fix.smem_len;
198 
199 	pmagbafb_erase_cursor(info);
200 
201 	err = register_framebuffer(info);
202 	if (err < 0) {
203 		printk(KERN_ERR "%s: Cannot register framebuffer\n",
204 		       dev_name(dev));
205 		goto err_smem_map;
206 	}
207 
208 	get_device(dev);
209 
210 	fb_info(info, "%s frame buffer device at %s\n",
211 		info->fix.id, dev_name(dev));
212 
213 	return 0;
214 
215 
216 err_smem_map:
217 	iounmap(info->screen_base);
218 
219 err_mmio_map:
220 	iounmap(par->mmio);
221 
222 err_resource:
223 	release_mem_region(start, len);
224 
225 err_cmap:
226 	fb_dealloc_cmap(&info->cmap);
227 
228 err_alloc:
229 	framebuffer_release(info);
230 	return err;
231 }
232 
pmagbafb_remove(struct device * dev)233 static int pmagbafb_remove(struct device *dev)
234 {
235 	struct tc_dev *tdev = to_tc_dev(dev);
236 	struct fb_info *info = dev_get_drvdata(dev);
237 	struct pmagbafb_par *par = info->par;
238 	resource_size_t start, len;
239 
240 	put_device(dev);
241 	unregister_framebuffer(info);
242 	iounmap(info->screen_base);
243 	iounmap(par->mmio);
244 	start = tdev->resource.start;
245 	len = tdev->resource.end - start + 1;
246 	release_mem_region(start, len);
247 	fb_dealloc_cmap(&info->cmap);
248 	framebuffer_release(info);
249 	return 0;
250 }
251 
252 
253 /*
254  * Initialize the framebuffer.
255  */
256 static const struct tc_device_id pmagbafb_tc_table[] = {
257 	{ "DEC     ", "PMAG-BA " },
258 	{ }
259 };
260 MODULE_DEVICE_TABLE(tc, pmagbafb_tc_table);
261 
262 static struct tc_driver pmagbafb_driver = {
263 	.id_table	= pmagbafb_tc_table,
264 	.driver		= {
265 		.name	= "pmagbafb",
266 		.bus	= &tc_bus_type,
267 		.probe	= pmagbafb_probe,
268 		.remove	= pmagbafb_remove,
269 	},
270 };
271 
pmagbafb_init(void)272 static int __init pmagbafb_init(void)
273 {
274 #ifndef MODULE
275 	if (fb_get_options("pmagbafb", NULL))
276 		return -ENXIO;
277 #endif
278 	return tc_register_driver(&pmagbafb_driver);
279 }
280 
pmagbafb_exit(void)281 static void __exit pmagbafb_exit(void)
282 {
283 	tc_unregister_driver(&pmagbafb_driver);
284 }
285 
286 
287 module_init(pmagbafb_init);
288 module_exit(pmagbafb_exit);
289 
290 MODULE_LICENSE("GPL");
291