xref: /linux/drivers/video/fbdev/cg3.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942) 
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.h>
21 #include <linux/platform_device.h>
22 
23 #include <asm/io.h>
24 #include <asm/fbio.h>
25 
26 #include "sbuslib.h"
27 
28 /*
29  * Local functions.
30  */
31 
32 static int cg3_setcolreg(unsigned, unsigned, unsigned, unsigned,
33 			 unsigned, struct fb_info *);
34 static int cg3_blank(int, struct fb_info *);
35 
36 static int cg3_sbusfb_mmap(struct fb_info *info, struct vm_area_struct *vma);
37 static int cg3_sbusfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg);
38 
39 /*
40  *  Frame buffer operations
41  */
42 
43 static const struct fb_ops cg3_ops = {
44 	.owner			= THIS_MODULE,
45 	FB_DEFAULT_SBUS_OPS(cg3),
46 	.fb_setcolreg		= cg3_setcolreg,
47 	.fb_blank		= cg3_blank,
48 };
49 
50 
51 /* Control Register Constants */
52 #define CG3_CR_ENABLE_INTS      0x80
53 #define CG3_CR_ENABLE_VIDEO     0x40
54 #define CG3_CR_ENABLE_TIMING    0x20
55 #define CG3_CR_ENABLE_CURCMP    0x10
56 #define CG3_CR_XTAL_MASK        0x0c
57 #define CG3_CR_DIVISOR_MASK     0x03
58 
59 /* Status Register Constants */
60 #define CG3_SR_PENDING_INT      0x80
61 #define CG3_SR_RES_MASK         0x70
62 #define CG3_SR_1152_900_76_A    0x40
63 #define CG3_SR_1152_900_76_B    0x60
64 #define CG3_SR_ID_MASK          0x0f
65 #define CG3_SR_ID_COLOR         0x01
66 #define CG3_SR_ID_MONO          0x02
67 #define CG3_SR_ID_MONO_ECL      0x03
68 
69 enum cg3_type {
70 	CG3_AT_66HZ = 0,
71 	CG3_AT_76HZ,
72 	CG3_RDI
73 };
74 
75 struct bt_regs {
76 	u32 addr;
77 	u32 color_map;
78 	u32 control;
79 	u32 cursor;
80 };
81 
82 struct cg3_regs {
83 	struct bt_regs	cmap;
84 	u8	control;
85 	u8	status;
86 	u8	cursor_start;
87 	u8	cursor_end;
88 	u8	h_blank_start;
89 	u8	h_blank_end;
90 	u8	h_sync_start;
91 	u8	h_sync_end;
92 	u8	comp_sync_end;
93 	u8	v_blank_start_high;
94 	u8	v_blank_start_low;
95 	u8	v_blank_end;
96 	u8	v_sync_start;
97 	u8	v_sync_end;
98 	u8	xfer_holdoff_start;
99 	u8	xfer_holdoff_end;
100 };
101 
102 /* Offset of interesting structures in the OBIO space */
103 #define CG3_REGS_OFFSET	     0x400000UL
104 #define CG3_RAM_OFFSET	     0x800000UL
105 
106 struct cg3_par {
107 	spinlock_t		lock;
108 	struct cg3_regs		__iomem *regs;
109 	u32			sw_cmap[((256 * 3) + 3) / 4];
110 
111 	u32			flags;
112 #define CG3_FLAG_BLANKED	0x00000001
113 #define CG3_FLAG_RDI		0x00000002
114 
115 	unsigned long		which_io;
116 };
117 
118 /**
119  *      cg3_setcolreg - Optional function. Sets a color register.
120  *      @regno: boolean, 0 copy local, 1 get_user() function
121  *      @red: frame buffer colormap structure
122  *      @green: The green value which can be up to 16 bits wide
123  *      @blue:  The blue value which can be up to 16 bits wide.
124  *      @transp: If supported the alpha value which can be up to 16 bits wide.
125  *      @info: frame buffer info structure
126  *
127  * The cg3 palette is loaded with 4 color values at each time
128  * so you end up with: (rgb)(r), (gb)(rg), (b)(rgb), and so on.
129  * We keep a sw copy of the hw cmap to assist us in this esoteric
130  * loading procedure.
131  */
132 static int cg3_setcolreg(unsigned regno,
133 			 unsigned red, unsigned green, unsigned blue,
134 			 unsigned transp, struct fb_info *info)
135 {
136 	struct cg3_par *par = (struct cg3_par *) info->par;
137 	struct bt_regs __iomem *bt = &par->regs->cmap;
138 	unsigned long flags;
139 	u32 *p32;
140 	u8 *p8;
141 	int count;
142 
143 	if (regno >= 256)
144 		return 1;
145 
146 	red >>= 8;
147 	green >>= 8;
148 	blue >>= 8;
149 
150 	spin_lock_irqsave(&par->lock, flags);
151 
152 	p8 = (u8 *)par->sw_cmap + (regno * 3);
153 	p8[0] = red;
154 	p8[1] = green;
155 	p8[2] = blue;
156 
157 #define D4M3(x) ((((x)>>2)<<1) + ((x)>>2))      /* (x/4)*3 */
158 #define D4M4(x) ((x)&~0x3)                      /* (x/4)*4 */
159 
160 	count = 3;
161 	p32 = &par->sw_cmap[D4M3(regno)];
162 	sbus_writel(D4M4(regno), &bt->addr);
163 	while (count--)
164 		sbus_writel(*p32++, &bt->color_map);
165 
166 #undef D4M3
167 #undef D4M4
168 
169 	spin_unlock_irqrestore(&par->lock, flags);
170 
171 	return 0;
172 }
173 
174 /**
175  *      cg3_blank - Optional function.  Blanks the display.
176  *      @blank: the blank mode we want.
177  *      @info: frame buffer structure that represents a single frame buffer
178  */
179 static int cg3_blank(int blank, struct fb_info *info)
180 {
181 	struct cg3_par *par = (struct cg3_par *) info->par;
182 	struct cg3_regs __iomem *regs = par->regs;
183 	unsigned long flags;
184 	u8 val;
185 
186 	spin_lock_irqsave(&par->lock, flags);
187 
188 	switch (blank) {
189 	case FB_BLANK_UNBLANK: /* Unblanking */
190 		val = sbus_readb(&regs->control);
191 		val |= CG3_CR_ENABLE_VIDEO;
192 		sbus_writeb(val, &regs->control);
193 		par->flags &= ~CG3_FLAG_BLANKED;
194 		break;
195 
196 	case FB_BLANK_NORMAL: /* Normal blanking */
197 	case FB_BLANK_VSYNC_SUSPEND: /* VESA blank (vsync off) */
198 	case FB_BLANK_HSYNC_SUSPEND: /* VESA blank (hsync off) */
199 	case FB_BLANK_POWERDOWN: /* Poweroff */
200 		val = sbus_readb(&regs->control);
201 		val &= ~CG3_CR_ENABLE_VIDEO;
202 		sbus_writeb(val, &regs->control);
203 		par->flags |= CG3_FLAG_BLANKED;
204 		break;
205 	}
206 
207 	spin_unlock_irqrestore(&par->lock, flags);
208 
209 	return 0;
210 }
211 
212 static struct sbus_mmap_map cg3_mmap_map[] = {
213 	{
214 		.voff	= CG3_MMAP_OFFSET,
215 		.poff	= CG3_RAM_OFFSET,
216 		.size	= SBUS_MMAP_FBSIZE(1)
217 	},
218 	{ .size = 0 }
219 };
220 
221 static int cg3_sbusfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
222 {
223 	struct cg3_par *par = (struct cg3_par *)info->par;
224 
225 	return sbusfb_mmap_helper(cg3_mmap_map,
226 				  info->fix.smem_start, info->fix.smem_len,
227 				  par->which_io,
228 				  vma);
229 }
230 
231 static int cg3_sbusfb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
232 {
233 	return sbusfb_ioctl_helper(cmd, arg, info,
234 				   FBTYPE_SUN3COLOR, 8, info->fix.smem_len);
235 }
236 
237 /*
238  *  Initialisation
239  */
240 
241 static void cg3_init_fix(struct fb_info *info, int linebytes,
242 			 struct device_node *dp)
243 {
244 	snprintf(info->fix.id, sizeof(info->fix.id), "%pOFn", dp);
245 
246 	info->fix.type = FB_TYPE_PACKED_PIXELS;
247 	info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
248 
249 	info->fix.line_length = linebytes;
250 
251 	info->fix.accel = FB_ACCEL_SUN_CGTHREE;
252 }
253 
254 static void cg3_rdi_maybe_fixup_var(struct fb_var_screeninfo *var,
255 				    struct device_node *dp)
256 {
257 	const char *params;
258 	char *p;
259 	int ww, hh;
260 
261 	params = of_get_property(dp, "params", NULL);
262 	if (params) {
263 		ww = simple_strtoul(params, &p, 10);
264 		if (ww && *p == 'x') {
265 			hh = simple_strtoul(p + 1, &p, 10);
266 			if (hh && *p == '-') {
267 				if (var->xres != ww ||
268 				    var->yres != hh) {
269 					var->xres = var->xres_virtual = ww;
270 					var->yres = var->yres_virtual = hh;
271 				}
272 			}
273 		}
274 	}
275 }
276 
277 static u8 cg3regvals_66hz[] = {	/* 1152 x 900, 66 Hz */
278 	0x14, 0xbb,	0x15, 0x2b,	0x16, 0x04,	0x17, 0x14,
279 	0x18, 0xae,	0x19, 0x03,	0x1a, 0xa8,	0x1b, 0x24,
280 	0x1c, 0x01,	0x1d, 0x05,	0x1e, 0xff,	0x1f, 0x01,
281 	0x10, 0x20,	0
282 };
283 
284 static u8 cg3regvals_76hz[] = {	/* 1152 x 900, 76 Hz */
285 	0x14, 0xb7,	0x15, 0x27,	0x16, 0x03,	0x17, 0x0f,
286 	0x18, 0xae,	0x19, 0x03,	0x1a, 0xae,	0x1b, 0x2a,
287 	0x1c, 0x01,	0x1d, 0x09,	0x1e, 0xff,	0x1f, 0x01,
288 	0x10, 0x24,	0
289 };
290 
291 static u8 cg3regvals_rdi[] = {	/* 640 x 480, cgRDI */
292 	0x14, 0x70,	0x15, 0x20,	0x16, 0x08,	0x17, 0x10,
293 	0x18, 0x06,	0x19, 0x02,	0x1a, 0x31,	0x1b, 0x51,
294 	0x1c, 0x06,	0x1d, 0x0c,	0x1e, 0xff,	0x1f, 0x01,
295 	0x10, 0x22,	0
296 };
297 
298 static u8 *cg3_regvals[] = {
299 	cg3regvals_66hz, cg3regvals_76hz, cg3regvals_rdi
300 };
301 
302 static u_char cg3_dacvals[] = {
303 	4, 0xff,	5, 0x00,	6, 0x70,	7, 0x00,	0
304 };
305 
306 static int cg3_do_default_mode(struct cg3_par *par)
307 {
308 	enum cg3_type type;
309 	u8 *p;
310 
311 	if (par->flags & CG3_FLAG_RDI)
312 		type = CG3_RDI;
313 	else {
314 		u8 status = sbus_readb(&par->regs->status), mon;
315 		if ((status & CG3_SR_ID_MASK) == CG3_SR_ID_COLOR) {
316 			mon = status & CG3_SR_RES_MASK;
317 			if (mon == CG3_SR_1152_900_76_A ||
318 			    mon == CG3_SR_1152_900_76_B)
319 				type = CG3_AT_76HZ;
320 			else
321 				type = CG3_AT_66HZ;
322 		} else {
323 			printk(KERN_ERR "cgthree: can't handle SR %02x\n",
324 			       status);
325 			return -EINVAL;
326 		}
327 	}
328 
329 	for (p = cg3_regvals[type]; *p; p += 2) {
330 		u8 __iomem *regp = &((u8 __iomem *)par->regs)[p[0]];
331 		sbus_writeb(p[1], regp);
332 	}
333 	for (p = cg3_dacvals; *p; p += 2) {
334 		u8 __iomem *regp;
335 
336 		regp = (u8 __iomem *)&par->regs->cmap.addr;
337 		sbus_writeb(p[0], regp);
338 		regp = (u8 __iomem *)&par->regs->cmap.control;
339 		sbus_writeb(p[1], regp);
340 	}
341 	return 0;
342 }
343 
344 static int cg3_probe(struct platform_device *op)
345 {
346 	struct device_node *dp = op->dev.of_node;
347 	struct fb_info *info;
348 	struct cg3_par *par;
349 	int linebytes, err;
350 
351 	info = framebuffer_alloc(sizeof(struct cg3_par), &op->dev);
352 
353 	err = -ENOMEM;
354 	if (!info)
355 		goto out_err;
356 	par = info->par;
357 
358 	spin_lock_init(&par->lock);
359 
360 	info->fix.smem_start = op->resource[0].start;
361 	par->which_io = op->resource[0].flags & IORESOURCE_BITS;
362 
363 	sbusfb_fill_var(&info->var, dp, 8);
364 	info->var.red.length = 8;
365 	info->var.green.length = 8;
366 	info->var.blue.length = 8;
367 	if (of_node_name_eq(dp, "cgRDI"))
368 		par->flags |= CG3_FLAG_RDI;
369 	if (par->flags & CG3_FLAG_RDI)
370 		cg3_rdi_maybe_fixup_var(&info->var, dp);
371 
372 	linebytes = of_getintprop_default(dp, "linebytes",
373 					  info->var.xres);
374 	info->fix.smem_len = PAGE_ALIGN(linebytes * info->var.yres);
375 
376 	par->regs = of_ioremap(&op->resource[0], CG3_REGS_OFFSET,
377 			       sizeof(struct cg3_regs), "cg3 regs");
378 	if (!par->regs)
379 		goto out_release_fb;
380 
381 	info->fbops = &cg3_ops;
382 	info->screen_base = of_ioremap(&op->resource[0], CG3_RAM_OFFSET,
383 				       info->fix.smem_len, "cg3 ram");
384 	if (!info->screen_base)
385 		goto out_unmap_regs;
386 
387 	cg3_blank(FB_BLANK_UNBLANK, info);
388 
389 	if (!of_property_present(dp, "width")) {
390 		err = cg3_do_default_mode(par);
391 		if (err)
392 			goto out_unmap_screen;
393 	}
394 
395 	err = fb_alloc_cmap(&info->cmap, 256, 0);
396 	if (err)
397 		goto out_unmap_screen;
398 
399 	fb_set_cmap(&info->cmap, info);
400 
401 	cg3_init_fix(info, linebytes, dp);
402 
403 	err = register_framebuffer(info);
404 	if (err < 0)
405 		goto out_dealloc_cmap;
406 
407 	dev_set_drvdata(&op->dev, info);
408 
409 	printk(KERN_INFO "%pOF: cg3 at %lx:%lx\n",
410 	       dp, par->which_io, info->fix.smem_start);
411 
412 	return 0;
413 
414 out_dealloc_cmap:
415 	fb_dealloc_cmap(&info->cmap);
416 
417 out_unmap_screen:
418 	of_iounmap(&op->resource[0], info->screen_base, info->fix.smem_len);
419 
420 out_unmap_regs:
421 	of_iounmap(&op->resource[0], par->regs, sizeof(struct cg3_regs));
422 
423 out_release_fb:
424 	framebuffer_release(info);
425 
426 out_err:
427 	return err;
428 }
429 
430 static void cg3_remove(struct platform_device *op)
431 {
432 	struct fb_info *info = dev_get_drvdata(&op->dev);
433 	struct cg3_par *par = info->par;
434 
435 	unregister_framebuffer(info);
436 	fb_dealloc_cmap(&info->cmap);
437 
438 	of_iounmap(&op->resource[0], par->regs, sizeof(struct cg3_regs));
439 	of_iounmap(&op->resource[0], info->screen_base, info->fix.smem_len);
440 
441 	framebuffer_release(info);
442 }
443 
444 static const struct of_device_id cg3_match[] = {
445 	{
446 		.name = "cgthree",
447 	},
448 	{
449 		.name = "cgRDI",
450 	},
451 	{},
452 };
453 MODULE_DEVICE_TABLE(of, cg3_match);
454 
455 static struct platform_driver cg3_driver = {
456 	.driver = {
457 		.name = "cg3",
458 		.of_match_table = cg3_match,
459 	},
460 	.probe		= cg3_probe,
461 	.remove_new	= cg3_remove,
462 };
463 
464 static int __init cg3_init(void)
465 {
466 	if (fb_get_options("cg3fb", NULL))
467 		return -ENODEV;
468 
469 	return platform_driver_register(&cg3_driver);
470 }
471 
472 static void __exit cg3_exit(void)
473 {
474 	platform_driver_unregister(&cg3_driver);
475 }
476 
477 module_init(cg3_init);
478 module_exit(cg3_exit);
479 
480 MODULE_DESCRIPTION("framebuffer driver for CGthree chipsets");
481 MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
482 MODULE_VERSION("2.0");
483 MODULE_LICENSE("GPL");
484