xref: /openbmc/linux/drivers/video/fbdev/grvga.c (revision e3d786a3)
1 /*
2  * Driver for Aeroflex Gaisler SVGACTRL framebuffer device.
3  *
4  * 2011 (c) Aeroflex Gaisler AB
5  *
6  * Full documentation of the core can be found here:
7  * http://www.gaisler.com/products/grlib/grip.pdf
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License as published by the
11  * Free Software Foundation; either version 2 of the License, or (at your
12  * option) any later version.
13  *
14  * Contributors: Kristoffer Glembo <kristoffer@gaisler.com>
15  *
16  */
17 
18 #include <linux/platform_device.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/of_platform.h>
21 #include <linux/of_device.h>
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/string.h>
25 #include <linux/delay.h>
26 #include <linux/errno.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/tty.h>
30 #include <linux/mm.h>
31 #include <linux/fb.h>
32 #include <linux/io.h>
33 
34 struct grvga_regs {
35 	u32 status; 		/* 0x00 */
36 	u32 video_length; 	/* 0x04 */
37 	u32 front_porch;	/* 0x08 */
38 	u32 sync_length;	/* 0x0C */
39 	u32 line_length;	/* 0x10 */
40 	u32 fb_pos;		/* 0x14 */
41 	u32 clk_vector[4];	/* 0x18 */
42 	u32 clut;	        /* 0x20 */
43 };
44 
45 struct grvga_par {
46 	struct grvga_regs *regs;
47 	u32 color_palette[16];  /* 16 entry pseudo palette used by fbcon in true color mode */
48 	int clk_sel;
49 	int fb_alloced;         /* = 1 if framebuffer is allocated in main memory */
50 };
51 
52 
53 static const struct fb_videomode grvga_modedb[] = {
54     {
55 	/* 640x480 @ 60 Hz */
56 	NULL, 60, 640, 480, 40000, 48, 16, 39, 11, 96, 2,
57 	0, FB_VMODE_NONINTERLACED
58     }, {
59 	/* 800x600 @ 60 Hz */
60 	NULL, 60, 800, 600, 25000, 88, 40, 23, 1, 128, 4,
61 	0, FB_VMODE_NONINTERLACED
62     }, {
63 	/* 800x600 @ 72 Hz */
64 	NULL, 72, 800, 600, 20000, 64, 56, 23, 37, 120, 6,
65 	0, FB_VMODE_NONINTERLACED
66     }, {
67 	/* 1024x768 @ 60 Hz */
68 	NULL, 60, 1024, 768, 15385, 160, 24, 29, 3, 136, 6,
69 	0, FB_VMODE_NONINTERLACED
70     }
71  };
72 
73 static const struct fb_fix_screeninfo grvga_fix = {
74 	.id =		"AG SVGACTRL",
75 	.type =		FB_TYPE_PACKED_PIXELS,
76 	.visual =       FB_VISUAL_PSEUDOCOLOR,
77 	.xpanstep =	0,
78 	.ypanstep =	1,
79 	.ywrapstep =	0,
80 	.accel =	FB_ACCEL_NONE,
81 };
82 
83 static int grvga_check_var(struct fb_var_screeninfo *var,
84 			   struct fb_info *info)
85 {
86 	struct grvga_par *par = info->par;
87 	int i;
88 
89 	if (!var->xres)
90 		var->xres = 1;
91 	if (!var->yres)
92 		var->yres = 1;
93 	if (var->bits_per_pixel <= 8)
94 		var->bits_per_pixel = 8;
95 	else if (var->bits_per_pixel <= 16)
96 		var->bits_per_pixel = 16;
97 	else if (var->bits_per_pixel <= 24)
98 		var->bits_per_pixel = 24;
99 	else if (var->bits_per_pixel <= 32)
100 		var->bits_per_pixel = 32;
101 	else
102 		return -EINVAL;
103 
104 	var->xres_virtual = var->xres;
105 	var->yres_virtual = 2*var->yres;
106 
107 	if (info->fix.smem_len) {
108 		if ((var->yres_virtual*var->xres_virtual*var->bits_per_pixel/8) > info->fix.smem_len)
109 			return -ENOMEM;
110 	}
111 
112 	/* Which clocks that are available can be read out in these registers */
113 	for (i = 0; i <= 3 ; i++) {
114 		if (var->pixclock == par->regs->clk_vector[i])
115 			break;
116 	}
117 	if (i <= 3)
118 		par->clk_sel = i;
119 	else
120 		return -EINVAL;
121 
122 	switch (info->var.bits_per_pixel) {
123 	case 8:
124 		var->red   = (struct fb_bitfield) {0, 8, 0};      /* offset, length, msb-right */
125 		var->green = (struct fb_bitfield) {0, 8, 0};
126 		var->blue  = (struct fb_bitfield) {0, 8, 0};
127 		var->transp = (struct fb_bitfield) {0, 0, 0};
128 		break;
129 	case 16:
130 		var->red   = (struct fb_bitfield) {11, 5, 0};
131 		var->green = (struct fb_bitfield) {5, 6, 0};
132 		var->blue  = (struct fb_bitfield) {0, 5, 0};
133 		var->transp = (struct fb_bitfield) {0, 0, 0};
134 		break;
135 	case 24:
136 	case 32:
137 		var->red   = (struct fb_bitfield) {16, 8, 0};
138 		var->green = (struct fb_bitfield) {8, 8, 0};
139 		var->blue  = (struct fb_bitfield) {0, 8, 0};
140 		var->transp = (struct fb_bitfield) {24, 8, 0};
141 		break;
142 	default:
143 		return -EINVAL;
144 	}
145 
146 	return 0;
147 }
148 
149 static int grvga_set_par(struct fb_info *info)
150 {
151 
152 	u32 func = 0;
153 	struct grvga_par *par = info->par;
154 
155 	__raw_writel(((info->var.yres - 1) << 16) | (info->var.xres - 1),
156 		     &par->regs->video_length);
157 
158 	__raw_writel((info->var.lower_margin << 16) | (info->var.right_margin),
159 		     &par->regs->front_porch);
160 
161 	__raw_writel((info->var.vsync_len << 16) | (info->var.hsync_len),
162 		     &par->regs->sync_length);
163 
164 	__raw_writel(((info->var.yres + info->var.lower_margin + info->var.upper_margin + info->var.vsync_len - 1) << 16) |
165 		     (info->var.xres + info->var.right_margin + info->var.left_margin + info->var.hsync_len - 1),
166 		     &par->regs->line_length);
167 
168 	switch (info->var.bits_per_pixel) {
169 	case 8:
170 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
171 		func = 1;
172 		break;
173 	case 16:
174 		info->fix.visual = FB_VISUAL_TRUECOLOR;
175 		func = 2;
176 		break;
177 	case 24:
178 	case 32:
179 		info->fix.visual = FB_VISUAL_TRUECOLOR;
180 		func = 3;
181 		break;
182 	default:
183 		return -EINVAL;
184 	}
185 
186 	__raw_writel((par->clk_sel << 6) | (func << 4) | 1,
187 		     &par->regs->status);
188 
189 	info->fix.line_length = (info->var.xres_virtual*info->var.bits_per_pixel)/8;
190 	return 0;
191 }
192 
193 static int grvga_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info)
194 {
195 	struct grvga_par *par;
196 	par = info->par;
197 
198 	if (regno >= 256)	/* Size of CLUT */
199 		return -EINVAL;
200 
201 	if (info->var.grayscale) {
202 		/* grayscale = 0.30*R + 0.59*G + 0.11*B */
203 		red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
204 	}
205 
206 
207 
208 #define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
209 
210 	red    = CNVT_TOHW(red,   info->var.red.length);
211 	green  = CNVT_TOHW(green, info->var.green.length);
212 	blue   = CNVT_TOHW(blue,  info->var.blue.length);
213 	transp = CNVT_TOHW(transp, info->var.transp.length);
214 
215 #undef CNVT_TOHW
216 
217 	/* In PSEUDOCOLOR we use the hardware CLUT */
218 	if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR)
219 		__raw_writel((regno << 24) | (red << 16) | (green << 8) | blue,
220 			     &par->regs->clut);
221 
222 	/* Truecolor uses the pseudo palette */
223 	else if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
224 		u32 v;
225 		if (regno >= 16)
226 			return -EINVAL;
227 
228 
229 		v =     (red    << info->var.red.offset)   |
230 			(green  << info->var.green.offset) |
231 			(blue   << info->var.blue.offset)  |
232 			(transp << info->var.transp.offset);
233 
234 		((u32 *) (info->pseudo_palette))[regno] = v;
235 	}
236 	return 0;
237 }
238 
239 static int grvga_pan_display(struct fb_var_screeninfo *var,
240 			     struct fb_info *info)
241 {
242 	struct grvga_par *par = info->par;
243 	struct fb_fix_screeninfo *fix = &info->fix;
244 	u32 base_addr;
245 
246 	if (var->xoffset != 0)
247 		return -EINVAL;
248 
249 	base_addr = fix->smem_start + (var->yoffset * fix->line_length);
250 	base_addr &= ~3UL;
251 
252 	/* Set framebuffer base address  */
253 	__raw_writel(base_addr,
254 		     &par->regs->fb_pos);
255 
256 	return 0;
257 }
258 
259 static struct fb_ops grvga_ops = {
260 	.owner          = THIS_MODULE,
261 	.fb_check_var   = grvga_check_var,
262 	.fb_set_par	= grvga_set_par,
263 	.fb_setcolreg   = grvga_setcolreg,
264 	.fb_pan_display = grvga_pan_display,
265 	.fb_fillrect	= cfb_fillrect,
266 	.fb_copyarea	= cfb_copyarea,
267 	.fb_imageblit	= cfb_imageblit
268 };
269 
270 static int grvga_parse_custom(char *options,
271 			      struct fb_var_screeninfo *screendata)
272 {
273 	char *this_opt;
274 	int count = 0;
275 	if (!options || !*options)
276 		return -1;
277 
278 	while ((this_opt = strsep(&options, " ")) != NULL) {
279 		if (!*this_opt)
280 			continue;
281 
282 		switch (count) {
283 		case 0:
284 			screendata->pixclock = simple_strtoul(this_opt, NULL, 0);
285 			count++;
286 			break;
287 		case 1:
288 			screendata->xres = screendata->xres_virtual = simple_strtoul(this_opt, NULL, 0);
289 			count++;
290 			break;
291 		case 2:
292 			screendata->right_margin = simple_strtoul(this_opt, NULL, 0);
293 			count++;
294 			break;
295 		case 3:
296 			screendata->hsync_len = simple_strtoul(this_opt, NULL, 0);
297 			count++;
298 			break;
299 		case 4:
300 			screendata->left_margin = simple_strtoul(this_opt, NULL, 0);
301 			count++;
302 			break;
303 		case 5:
304 			screendata->yres = screendata->yres_virtual = simple_strtoul(this_opt, NULL, 0);
305 			count++;
306 			break;
307 		case 6:
308 			screendata->lower_margin = simple_strtoul(this_opt, NULL, 0);
309 			count++;
310 			break;
311 		case 7:
312 			screendata->vsync_len = simple_strtoul(this_opt, NULL, 0);
313 			count++;
314 			break;
315 		case 8:
316 			screendata->upper_margin = simple_strtoul(this_opt, NULL, 0);
317 			count++;
318 			break;
319 		case 9:
320 			screendata->bits_per_pixel = simple_strtoul(this_opt, NULL, 0);
321 			count++;
322 			break;
323 		default:
324 			return -1;
325 		}
326 	}
327 	screendata->activate  = FB_ACTIVATE_NOW;
328 	screendata->vmode     = FB_VMODE_NONINTERLACED;
329 	return 0;
330 }
331 
332 static int grvga_probe(struct platform_device *dev)
333 {
334 	struct fb_info *info;
335 	int retval = -ENOMEM;
336 	unsigned long virtual_start;
337 	unsigned long grvga_fix_addr = 0;
338 	unsigned long physical_start = 0;
339 	unsigned long grvga_mem_size = 0;
340 	struct grvga_par *par = NULL;
341 	char *options = NULL, *mode_opt = NULL;
342 
343 	info = framebuffer_alloc(sizeof(struct grvga_par), &dev->dev);
344 	if (!info) {
345 		dev_err(&dev->dev, "framebuffer_alloc failed\n");
346 		return -ENOMEM;
347 	}
348 
349 	/* Expecting: "grvga: modestring, [addr:<framebuffer physical address>], [size:<framebuffer size>]
350 	 *
351 	 * If modestring is custom:<custom mode string> we parse the string which then contains all videoparameters
352 	 * If address is left out, we allocate memory,
353 	 * if size is left out we only allocate enough to support the given mode.
354 	 */
355 	if (fb_get_options("grvga", &options)) {
356 		retval = -ENODEV;
357 		goto free_fb;
358 	}
359 
360 	if (!options || !*options)
361 		options =  "640x480-8@60";
362 
363 	while (1) {
364 		char *this_opt = strsep(&options, ",");
365 
366 		if (!this_opt)
367 			break;
368 
369 		if (!strncmp(this_opt, "custom", 6)) {
370 			if (grvga_parse_custom(this_opt, &info->var) < 0) {
371 				dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
372 				retval = -EINVAL;
373 				goto free_fb;
374 			}
375 		} else if (!strncmp(this_opt, "addr", 4))
376 			grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
377 		else if (!strncmp(this_opt, "size", 4))
378 			grvga_mem_size = simple_strtoul(this_opt + 5, NULL, 0);
379 		else
380 			mode_opt = this_opt;
381 	}
382 
383 	par = info->par;
384 	info->fbops = &grvga_ops;
385 	info->fix = grvga_fix;
386 	info->pseudo_palette = par->color_palette;
387 	info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
388 	info->fix.smem_len = grvga_mem_size;
389 
390 	if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
391 		    resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
392 		dev_err(&dev->dev, "registers already mapped\n");
393 		retval = -EBUSY;
394 		goto free_fb;
395 	}
396 
397 	par->regs = of_ioremap(&dev->resource[0], 0,
398 			       resource_size(&dev->resource[0]),
399 			       "grlib-svgactrl regs");
400 
401 	if (!par->regs) {
402 		dev_err(&dev->dev, "failed to map registers\n");
403 		retval = -ENOMEM;
404 		goto free_fb;
405 	}
406 
407 	retval = fb_alloc_cmap(&info->cmap, 256, 0);
408 	if (retval < 0) {
409 		dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
410 		retval = -ENOMEM;
411 		goto unmap_regs;
412 	}
413 
414 	if (mode_opt) {
415 		retval = fb_find_mode(&info->var, info, mode_opt,
416 				      grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
417 		if (!retval || retval == 4) {
418 			retval = -EINVAL;
419 			goto dealloc_cmap;
420 		}
421 	}
422 
423 	if (!grvga_mem_size)
424 		grvga_mem_size = info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel/8;
425 
426 	if (grvga_fix_addr) {
427 		/* Got framebuffer base address from argument list */
428 
429 		physical_start = grvga_fix_addr;
430 
431 		if (!devm_request_mem_region(&dev->dev, physical_start,
432 					     grvga_mem_size, dev->name)) {
433 			dev_err(&dev->dev, "failed to request memory region\n");
434 			retval = -ENOMEM;
435 			goto dealloc_cmap;
436 		}
437 
438 		virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
439 
440 		if (!virtual_start) {
441 			dev_err(&dev->dev, "error mapping framebuffer memory\n");
442 			retval = -ENOMEM;
443 			goto dealloc_cmap;
444 		}
445 	} else {	/* Allocate frambuffer memory */
446 
447 		unsigned long page;
448 
449 		virtual_start = (unsigned long) __get_free_pages(GFP_DMA,
450 								 get_order(grvga_mem_size));
451 		if (!virtual_start) {
452 			dev_err(&dev->dev,
453 				"unable to allocate framebuffer memory (%lu bytes)\n",
454 				grvga_mem_size);
455 			retval = -ENOMEM;
456 			goto dealloc_cmap;
457 		}
458 
459 		physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
460 
461 		/* Set page reserved so that mmap will work. This is necessary
462 		 * since we'll be remapping normal memory.
463 		 */
464 		for (page = virtual_start;
465 		     page < PAGE_ALIGN(virtual_start + grvga_mem_size);
466 		     page += PAGE_SIZE) {
467 			SetPageReserved(virt_to_page(page));
468 		}
469 
470 		par->fb_alloced = 1;
471 	}
472 
473 	memset((unsigned long *) virtual_start, 0, grvga_mem_size);
474 
475 	info->screen_base = (char __iomem *) virtual_start;
476 	info->fix.smem_start = physical_start;
477 	info->fix.smem_len   = grvga_mem_size;
478 
479 	dev_set_drvdata(&dev->dev, info);
480 
481 	dev_info(&dev->dev,
482 		 "Aeroflex Gaisler framebuffer device (fb%d), %dx%d-%d, using %luK of video memory @ %p\n",
483 		 info->node, info->var.xres, info->var.yres, info->var.bits_per_pixel,
484 		 grvga_mem_size >> 10, info->screen_base);
485 
486 	retval = register_framebuffer(info);
487 	if (retval < 0) {
488 		dev_err(&dev->dev, "failed to register framebuffer\n");
489 		goto free_mem;
490 	}
491 
492 	__raw_writel(physical_start, &par->regs->fb_pos);
493 	__raw_writel(__raw_readl(&par->regs->status) | 1,  /* Enable framebuffer */
494 		     &par->regs->status);
495 
496 	return 0;
497 
498 free_mem:
499 	if (grvga_fix_addr)
500 		iounmap((void *)virtual_start);
501 	else
502 		kfree((void *)virtual_start);
503 dealloc_cmap:
504 	fb_dealloc_cmap(&info->cmap);
505 unmap_regs:
506 	of_iounmap(&dev->resource[0], par->regs,
507 		   resource_size(&dev->resource[0]));
508 free_fb:
509 	framebuffer_release(info);
510 
511 	return retval;
512 }
513 
514 static int grvga_remove(struct platform_device *device)
515 {
516 	struct fb_info *info = dev_get_drvdata(&device->dev);
517 	struct grvga_par *par;
518 
519 	if (info) {
520 		par = info->par;
521 		unregister_framebuffer(info);
522 		fb_dealloc_cmap(&info->cmap);
523 
524 		of_iounmap(&device->resource[0], par->regs,
525 			   resource_size(&device->resource[0]));
526 
527 		if (!par->fb_alloced)
528 			iounmap(info->screen_base);
529 		else
530 			kfree((void *)info->screen_base);
531 
532 		framebuffer_release(info);
533 	}
534 
535 	return 0;
536 }
537 
538 static struct of_device_id svgactrl_of_match[] = {
539 	{
540 		.name = "GAISLER_SVGACTRL",
541 	},
542 	{
543 		.name = "01_063",
544 	},
545 	{},
546 };
547 MODULE_DEVICE_TABLE(of, svgactrl_of_match);
548 
549 static struct platform_driver grvga_driver = {
550 	.driver = {
551 		.name = "grlib-svgactrl",
552 		.of_match_table = svgactrl_of_match,
553 	},
554 	.probe		= grvga_probe,
555 	.remove		= grvga_remove,
556 };
557 
558 module_platform_driver(grvga_driver);
559 
560 MODULE_LICENSE("GPL");
561 MODULE_AUTHOR("Aeroflex Gaisler");
562 MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");
563