xref: /linux/drivers/video/fbdev/cg3.c (revision 89755ee1d59311855b4afcf35aebddcb653b3cd5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* cg3.c: CGTHREE frame buffer driver
3  *
4  * Copyright (C) 2003, 2006 David S. Miller (davem@davemloft.net)
5  * Copyright (C) 1996,1998 Jakub Jelinek (jj@ultra.linux.cz)
6  * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
7  * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
8  *
9  * Driver layout based loosely on tgafb.c, see that file for credits.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/delay.h>
17 #include <linux/init.h>
18 #include <linux/fb.h>
19 #include <linux/mm.h>
20 #include <linux/of_device.h>
21 
22 #include <asm/io.h>
23 #include <asm/fbio.h>
24 
25 #include "sbuslib.h"
26 
27 /*
28  * Local functions.
29  */
30 
31 static int cg3_setcolreg(unsigned, unsigned, unsigned, unsigned,
32 			 unsigned, struct fb_info *);
33 static int cg3_blank(int, struct fb_info *);
34 
35 static int cg3_sbusfb_mmap(struct fb_info *info, struct vm_area_struct *vma);
36 static int cg3_sbusfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg);
37 
38 /*
39  *  Frame buffer operations
40  */
41 
42 static const struct fb_ops cg3_ops = {
43 	.owner			= THIS_MODULE,
44 	FB_DEFAULT_SBUS_OPS(cg3),
45 	.fb_setcolreg		= cg3_setcolreg,
46 	.fb_blank		= cg3_blank,
47 };
48 
49 
50 /* Control Register Constants */
51 #define CG3_CR_ENABLE_INTS      0x80
52 #define CG3_CR_ENABLE_VIDEO     0x40
53 #define CG3_CR_ENABLE_TIMING    0x20
54 #define CG3_CR_ENABLE_CURCMP    0x10
55 #define CG3_CR_XTAL_MASK        0x0c
56 #define CG3_CR_DIVISOR_MASK     0x03
57 
58 /* Status Register Constants */
59 #define CG3_SR_PENDING_INT      0x80
60 #define CG3_SR_RES_MASK         0x70
61 #define CG3_SR_1152_900_76_A    0x40
62 #define CG3_SR_1152_900_76_B    0x60
63 #define CG3_SR_ID_MASK          0x0f
64 #define CG3_SR_ID_COLOR         0x01
65 #define CG3_SR_ID_MONO          0x02
66 #define CG3_SR_ID_MONO_ECL      0x03
67 
68 enum cg3_type {
69 	CG3_AT_66HZ = 0,
70 	CG3_AT_76HZ,
71 	CG3_RDI
72 };
73 
74 struct bt_regs {
75 	u32 addr;
76 	u32 color_map;
77 	u32 control;
78 	u32 cursor;
79 };
80 
81 struct cg3_regs {
82 	struct bt_regs	cmap;
83 	u8	control;
84 	u8	status;
85 	u8	cursor_start;
86 	u8	cursor_end;
87 	u8	h_blank_start;
88 	u8	h_blank_end;
89 	u8	h_sync_start;
90 	u8	h_sync_end;
91 	u8	comp_sync_end;
92 	u8	v_blank_start_high;
93 	u8	v_blank_start_low;
94 	u8	v_blank_end;
95 	u8	v_sync_start;
96 	u8	v_sync_end;
97 	u8	xfer_holdoff_start;
98 	u8	xfer_holdoff_end;
99 };
100 
101 /* Offset of interesting structures in the OBIO space */
102 #define CG3_REGS_OFFSET	     0x400000UL
103 #define CG3_RAM_OFFSET	     0x800000UL
104 
105 struct cg3_par {
106 	spinlock_t		lock;
107 	struct cg3_regs		__iomem *regs;
108 	u32			sw_cmap[((256 * 3) + 3) / 4];
109 
110 	u32			flags;
111 #define CG3_FLAG_BLANKED	0x00000001
112 #define CG3_FLAG_RDI		0x00000002
113 
114 	unsigned long		which_io;
115 };
116 
117 /**
118  *      cg3_setcolreg - Optional function. Sets a color register.
119  *      @regno: boolean, 0 copy local, 1 get_user() function
120  *      @red: frame buffer colormap structure
121  *      @green: The green value which can be up to 16 bits wide
122  *      @blue:  The blue value which can be up to 16 bits wide.
123  *      @transp: If supported the alpha value which can be up to 16 bits wide.
124  *      @info: frame buffer info structure
125  *
126  * The cg3 palette is loaded with 4 color values at each time
127  * so you end up with: (rgb)(r), (gb)(rg), (b)(rgb), and so on.
128  * We keep a sw copy of the hw cmap to assist us in this esoteric
129  * loading procedure.
130  */
131 static int cg3_setcolreg(unsigned regno,
132 			 unsigned red, unsigned green, unsigned blue,
133 			 unsigned transp, struct fb_info *info)
134 {
135 	struct cg3_par *par = (struct cg3_par *) info->par;
136 	struct bt_regs __iomem *bt = &par->regs->cmap;
137 	unsigned long flags;
138 	u32 *p32;
139 	u8 *p8;
140 	int count;
141 
142 	if (regno >= 256)
143 		return 1;
144 
145 	red >>= 8;
146 	green >>= 8;
147 	blue >>= 8;
148 
149 	spin_lock_irqsave(&par->lock, flags);
150 
151 	p8 = (u8 *)par->sw_cmap + (regno * 3);
152 	p8[0] = red;
153 	p8[1] = green;
154 	p8[2] = blue;
155 
156 #define D4M3(x) ((((x)>>2)<<1) + ((x)>>2))      /* (x/4)*3 */
157 #define D4M4(x) ((x)&~0x3)                      /* (x/4)*4 */
158 
159 	count = 3;
160 	p32 = &par->sw_cmap[D4M3(regno)];
161 	sbus_writel(D4M4(regno), &bt->addr);
162 	while (count--)
163 		sbus_writel(*p32++, &bt->color_map);
164 
165 #undef D4M3
166 #undef D4M4
167 
168 	spin_unlock_irqrestore(&par->lock, flags);
169 
170 	return 0;
171 }
172 
173 /**
174  *      cg3_blank - Optional function.  Blanks the display.
175  *      @blank: the blank mode we want.
176  *      @info: frame buffer structure that represents a single frame buffer
177  */
178 static int cg3_blank(int blank, struct fb_info *info)
179 {
180 	struct cg3_par *par = (struct cg3_par *) info->par;
181 	struct cg3_regs __iomem *regs = par->regs;
182 	unsigned long flags;
183 	u8 val;
184 
185 	spin_lock_irqsave(&par->lock, flags);
186 
187 	switch (blank) {
188 	case FB_BLANK_UNBLANK: /* Unblanking */
189 		val = sbus_readb(&regs->control);
190 		val |= CG3_CR_ENABLE_VIDEO;
191 		sbus_writeb(val, &regs->control);
192 		par->flags &= ~CG3_FLAG_BLANKED;
193 		break;
194 
195 	case FB_BLANK_NORMAL: /* Normal blanking */
196 	case FB_BLANK_VSYNC_SUSPEND: /* VESA blank (vsync off) */
197 	case FB_BLANK_HSYNC_SUSPEND: /* VESA blank (hsync off) */
198 	case FB_BLANK_POWERDOWN: /* Poweroff */
199 		val = sbus_readb(&regs->control);
200 		val &= ~CG3_CR_ENABLE_VIDEO;
201 		sbus_writeb(val, &regs->control);
202 		par->flags |= CG3_FLAG_BLANKED;
203 		break;
204 	}
205 
206 	spin_unlock_irqrestore(&par->lock, flags);
207 
208 	return 0;
209 }
210 
211 static struct sbus_mmap_map cg3_mmap_map[] = {
212 	{
213 		.voff	= CG3_MMAP_OFFSET,
214 		.poff	= CG3_RAM_OFFSET,
215 		.size	= SBUS_MMAP_FBSIZE(1)
216 	},
217 	{ .size = 0 }
218 };
219 
220 static int cg3_sbusfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
221 {
222 	struct cg3_par *par = (struct cg3_par *)info->par;
223 
224 	return sbusfb_mmap_helper(cg3_mmap_map,
225 				  info->fix.smem_start, info->fix.smem_len,
226 				  par->which_io,
227 				  vma);
228 }
229 
230 static int cg3_sbusfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
231 {
232 	return sbusfb_ioctl_helper(cmd, arg, info,
233 				   FBTYPE_SUN3COLOR, 8, info->fix.smem_len);
234 }
235 
236 /*
237  *  Initialisation
238  */
239 
240 static void cg3_init_fix(struct fb_info *info, int linebytes,
241 			 struct device_node *dp)
242 {
243 	snprintf(info->fix.id, sizeof(info->fix.id), "%pOFn", dp);
244 
245 	info->fix.type = FB_TYPE_PACKED_PIXELS;
246 	info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
247 
248 	info->fix.line_length = linebytes;
249 
250 	info->fix.accel = FB_ACCEL_SUN_CGTHREE;
251 }
252 
253 static void cg3_rdi_maybe_fixup_var(struct fb_var_screeninfo *var,
254 				    struct device_node *dp)
255 {
256 	const char *params;
257 	char *p;
258 	int ww, hh;
259 
260 	params = of_get_property(dp, "params", NULL);
261 	if (params) {
262 		ww = simple_strtoul(params, &p, 10);
263 		if (ww && *p == 'x') {
264 			hh = simple_strtoul(p + 1, &p, 10);
265 			if (hh && *p == '-') {
266 				if (var->xres != ww ||
267 				    var->yres != hh) {
268 					var->xres = var->xres_virtual = ww;
269 					var->yres = var->yres_virtual = hh;
270 				}
271 			}
272 		}
273 	}
274 }
275 
276 static u8 cg3regvals_66hz[] = {	/* 1152 x 900, 66 Hz */
277 	0x14, 0xbb,	0x15, 0x2b,	0x16, 0x04,	0x17, 0x14,
278 	0x18, 0xae,	0x19, 0x03,	0x1a, 0xa8,	0x1b, 0x24,
279 	0x1c, 0x01,	0x1d, 0x05,	0x1e, 0xff,	0x1f, 0x01,
280 	0x10, 0x20,	0
281 };
282 
283 static u8 cg3regvals_76hz[] = {	/* 1152 x 900, 76 Hz */
284 	0x14, 0xb7,	0x15, 0x27,	0x16, 0x03,	0x17, 0x0f,
285 	0x18, 0xae,	0x19, 0x03,	0x1a, 0xae,	0x1b, 0x2a,
286 	0x1c, 0x01,	0x1d, 0x09,	0x1e, 0xff,	0x1f, 0x01,
287 	0x10, 0x24,	0
288 };
289 
290 static u8 cg3regvals_rdi[] = {	/* 640 x 480, cgRDI */
291 	0x14, 0x70,	0x15, 0x20,	0x16, 0x08,	0x17, 0x10,
292 	0x18, 0x06,	0x19, 0x02,	0x1a, 0x31,	0x1b, 0x51,
293 	0x1c, 0x06,	0x1d, 0x0c,	0x1e, 0xff,	0x1f, 0x01,
294 	0x10, 0x22,	0
295 };
296 
297 static u8 *cg3_regvals[] = {
298 	cg3regvals_66hz, cg3regvals_76hz, cg3regvals_rdi
299 };
300 
301 static u_char cg3_dacvals[] = {
302 	4, 0xff,	5, 0x00,	6, 0x70,	7, 0x00,	0
303 };
304 
305 static int cg3_do_default_mode(struct cg3_par *par)
306 {
307 	enum cg3_type type;
308 	u8 *p;
309 
310 	if (par->flags & CG3_FLAG_RDI)
311 		type = CG3_RDI;
312 	else {
313 		u8 status = sbus_readb(&par->regs->status), mon;
314 		if ((status & CG3_SR_ID_MASK) == CG3_SR_ID_COLOR) {
315 			mon = status & CG3_SR_RES_MASK;
316 			if (mon == CG3_SR_1152_900_76_A ||
317 			    mon == CG3_SR_1152_900_76_B)
318 				type = CG3_AT_76HZ;
319 			else
320 				type = CG3_AT_66HZ;
321 		} else {
322 			printk(KERN_ERR "cgthree: can't handle SR %02x\n",
323 			       status);
324 			return -EINVAL;
325 		}
326 	}
327 
328 	for (p = cg3_regvals[type]; *p; p += 2) {
329 		u8 __iomem *regp = &((u8 __iomem *)par->regs)[p[0]];
330 		sbus_writeb(p[1], regp);
331 	}
332 	for (p = cg3_dacvals; *p; p += 2) {
333 		u8 __iomem *regp;
334 
335 		regp = (u8 __iomem *)&par->regs->cmap.addr;
336 		sbus_writeb(p[0], regp);
337 		regp = (u8 __iomem *)&par->regs->cmap.control;
338 		sbus_writeb(p[1], regp);
339 	}
340 	return 0;
341 }
342 
343 static int cg3_probe(struct platform_device *op)
344 {
345 	struct device_node *dp = op->dev.of_node;
346 	struct fb_info *info;
347 	struct cg3_par *par;
348 	int linebytes, err;
349 
350 	info = framebuffer_alloc(sizeof(struct cg3_par), &op->dev);
351 
352 	err = -ENOMEM;
353 	if (!info)
354 		goto out_err;
355 	par = info->par;
356 
357 	spin_lock_init(&par->lock);
358 
359 	info->fix.smem_start = op->resource[0].start;
360 	par->which_io = op->resource[0].flags & IORESOURCE_BITS;
361 
362 	sbusfb_fill_var(&info->var, dp, 8);
363 	info->var.red.length = 8;
364 	info->var.green.length = 8;
365 	info->var.blue.length = 8;
366 	if (of_node_name_eq(dp, "cgRDI"))
367 		par->flags |= CG3_FLAG_RDI;
368 	if (par->flags & CG3_FLAG_RDI)
369 		cg3_rdi_maybe_fixup_var(&info->var, dp);
370 
371 	linebytes = of_getintprop_default(dp, "linebytes",
372 					  info->var.xres);
373 	info->fix.smem_len = PAGE_ALIGN(linebytes * info->var.yres);
374 
375 	par->regs = of_ioremap(&op->resource[0], CG3_REGS_OFFSET,
376 			       sizeof(struct cg3_regs), "cg3 regs");
377 	if (!par->regs)
378 		goto out_release_fb;
379 
380 	info->fbops = &cg3_ops;
381 	info->screen_base = of_ioremap(&op->resource[0], CG3_RAM_OFFSET,
382 				       info->fix.smem_len, "cg3 ram");
383 	if (!info->screen_base)
384 		goto out_unmap_regs;
385 
386 	cg3_blank(FB_BLANK_UNBLANK, info);
387 
388 	if (!of_property_present(dp, "width")) {
389 		err = cg3_do_default_mode(par);
390 		if (err)
391 			goto out_unmap_screen;
392 	}
393 
394 	err = fb_alloc_cmap(&info->cmap, 256, 0);
395 	if (err)
396 		goto out_unmap_screen;
397 
398 	fb_set_cmap(&info->cmap, info);
399 
400 	cg3_init_fix(info, linebytes, dp);
401 
402 	err = register_framebuffer(info);
403 	if (err < 0)
404 		goto out_dealloc_cmap;
405 
406 	dev_set_drvdata(&op->dev, info);
407 
408 	printk(KERN_INFO "%pOF: cg3 at %lx:%lx\n",
409 	       dp, par->which_io, info->fix.smem_start);
410 
411 	return 0;
412 
413 out_dealloc_cmap:
414 	fb_dealloc_cmap(&info->cmap);
415 
416 out_unmap_screen:
417 	of_iounmap(&op->resource[0], info->screen_base, info->fix.smem_len);
418 
419 out_unmap_regs:
420 	of_iounmap(&op->resource[0], par->regs, sizeof(struct cg3_regs));
421 
422 out_release_fb:
423 	framebuffer_release(info);
424 
425 out_err:
426 	return err;
427 }
428 
429 static void cg3_remove(struct platform_device *op)
430 {
431 	struct fb_info *info = dev_get_drvdata(&op->dev);
432 	struct cg3_par *par = info->par;
433 
434 	unregister_framebuffer(info);
435 	fb_dealloc_cmap(&info->cmap);
436 
437 	of_iounmap(&op->resource[0], par->regs, sizeof(struct cg3_regs));
438 	of_iounmap(&op->resource[0], info->screen_base, info->fix.smem_len);
439 
440 	framebuffer_release(info);
441 }
442 
443 static const struct of_device_id cg3_match[] = {
444 	{
445 		.name = "cgthree",
446 	},
447 	{
448 		.name = "cgRDI",
449 	},
450 	{},
451 };
452 MODULE_DEVICE_TABLE(of, cg3_match);
453 
454 static struct platform_driver cg3_driver = {
455 	.driver = {
456 		.name = "cg3",
457 		.of_match_table = cg3_match,
458 	},
459 	.probe		= cg3_probe,
460 	.remove_new	= cg3_remove,
461 };
462 
463 static int __init cg3_init(void)
464 {
465 	if (fb_get_options("cg3fb", NULL))
466 		return -ENODEV;
467 
468 	return platform_driver_register(&cg3_driver);
469 }
470 
471 static void __exit cg3_exit(void)
472 {
473 	platform_driver_unregister(&cg3_driver);
474 }
475 
476 module_init(cg3_init);
477 module_exit(cg3_exit);
478 
479 MODULE_DESCRIPTION("framebuffer driver for CGthree chipsets");
480 MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
481 MODULE_VERSION("2.0");
482 MODULE_LICENSE("GPL");
483