xref: /linux/drivers/video/fbdev/grvga.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for Aeroflex Gaisler SVGACTRL framebuffer device.
4  *
5  * 2011 (c) Aeroflex Gaisler AB
6  *
7  * Full documentation of the core can be found here:
8  * http://www.gaisler.com/products/grlib/grip.pdf
9  *
10  * Contributors: Kristoffer Glembo <kristoffer@gaisler.com>
11  */
12 
13 #include <linux/platform_device.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/of_platform.h>
16 #include <linux/of_device.h>
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/delay.h>
21 #include <linux/errno.h>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/tty.h>
25 #include <linux/mm.h>
26 #include <linux/fb.h>
27 #include <linux/io.h>
28 
29 struct grvga_regs {
30 	u32 status; 		/* 0x00 */
31 	u32 video_length; 	/* 0x04 */
32 	u32 front_porch;	/* 0x08 */
33 	u32 sync_length;	/* 0x0C */
34 	u32 line_length;	/* 0x10 */
35 	u32 fb_pos;		/* 0x14 */
36 	u32 clk_vector[4];	/* 0x18 */
37 	u32 clut;	        /* 0x20 */
38 };
39 
40 struct grvga_par {
41 	struct grvga_regs *regs;
42 	u32 color_palette[16];  /* 16 entry pseudo palette used by fbcon in true color mode */
43 	int clk_sel;
44 	int fb_alloced;         /* = 1 if framebuffer is allocated in main memory */
45 };
46 
47 
48 static const struct fb_videomode grvga_modedb[] = {
49     {
50 	/* 640x480 @ 60 Hz */
51 	NULL, 60, 640, 480, 40000, 48, 16, 39, 11, 96, 2,
52 	0, FB_VMODE_NONINTERLACED
53     }, {
54 	/* 800x600 @ 60 Hz */
55 	NULL, 60, 800, 600, 25000, 88, 40, 23, 1, 128, 4,
56 	0, FB_VMODE_NONINTERLACED
57     }, {
58 	/* 800x600 @ 72 Hz */
59 	NULL, 72, 800, 600, 20000, 64, 56, 23, 37, 120, 6,
60 	0, FB_VMODE_NONINTERLACED
61     }, {
62 	/* 1024x768 @ 60 Hz */
63 	NULL, 60, 1024, 768, 15385, 160, 24, 29, 3, 136, 6,
64 	0, FB_VMODE_NONINTERLACED
65     }
66  };
67 
68 static const struct fb_fix_screeninfo grvga_fix = {
69 	.id =		"AG SVGACTRL",
70 	.type =		FB_TYPE_PACKED_PIXELS,
71 	.visual =       FB_VISUAL_PSEUDOCOLOR,
72 	.xpanstep =	0,
73 	.ypanstep =	1,
74 	.ywrapstep =	0,
75 	.accel =	FB_ACCEL_NONE,
76 };
77 
78 static int grvga_check_var(struct fb_var_screeninfo *var,
79 			   struct fb_info *info)
80 {
81 	struct grvga_par *par = info->par;
82 	int i;
83 
84 	if (!var->xres)
85 		var->xres = 1;
86 	if (!var->yres)
87 		var->yres = 1;
88 	if (var->bits_per_pixel <= 8)
89 		var->bits_per_pixel = 8;
90 	else if (var->bits_per_pixel <= 16)
91 		var->bits_per_pixel = 16;
92 	else if (var->bits_per_pixel <= 24)
93 		var->bits_per_pixel = 24;
94 	else if (var->bits_per_pixel <= 32)
95 		var->bits_per_pixel = 32;
96 	else
97 		return -EINVAL;
98 
99 	var->xres_virtual = var->xres;
100 	var->yres_virtual = 2*var->yres;
101 
102 	if (info->fix.smem_len) {
103 		if ((var->yres_virtual*var->xres_virtual*var->bits_per_pixel/8) > info->fix.smem_len)
104 			return -ENOMEM;
105 	}
106 
107 	/* Which clocks that are available can be read out in these registers */
108 	for (i = 0; i <= 3 ; i++) {
109 		if (var->pixclock == par->regs->clk_vector[i])
110 			break;
111 	}
112 	if (i <= 3)
113 		par->clk_sel = i;
114 	else
115 		return -EINVAL;
116 
117 	switch (info->var.bits_per_pixel) {
118 	case 8:
119 		var->red   = (struct fb_bitfield) {0, 8, 0};      /* offset, length, msb-right */
120 		var->green = (struct fb_bitfield) {0, 8, 0};
121 		var->blue  = (struct fb_bitfield) {0, 8, 0};
122 		var->transp = (struct fb_bitfield) {0, 0, 0};
123 		break;
124 	case 16:
125 		var->red   = (struct fb_bitfield) {11, 5, 0};
126 		var->green = (struct fb_bitfield) {5, 6, 0};
127 		var->blue  = (struct fb_bitfield) {0, 5, 0};
128 		var->transp = (struct fb_bitfield) {0, 0, 0};
129 		break;
130 	case 24:
131 	case 32:
132 		var->red   = (struct fb_bitfield) {16, 8, 0};
133 		var->green = (struct fb_bitfield) {8, 8, 0};
134 		var->blue  = (struct fb_bitfield) {0, 8, 0};
135 		var->transp = (struct fb_bitfield) {24, 8, 0};
136 		break;
137 	default:
138 		return -EINVAL;
139 	}
140 
141 	return 0;
142 }
143 
144 static int grvga_set_par(struct fb_info *info)
145 {
146 
147 	u32 func = 0;
148 	struct grvga_par *par = info->par;
149 
150 	__raw_writel(((info->var.yres - 1) << 16) | (info->var.xres - 1),
151 		     &par->regs->video_length);
152 
153 	__raw_writel((info->var.lower_margin << 16) | (info->var.right_margin),
154 		     &par->regs->front_porch);
155 
156 	__raw_writel((info->var.vsync_len << 16) | (info->var.hsync_len),
157 		     &par->regs->sync_length);
158 
159 	__raw_writel(((info->var.yres + info->var.lower_margin + info->var.upper_margin + info->var.vsync_len - 1) << 16) |
160 		     (info->var.xres + info->var.right_margin + info->var.left_margin + info->var.hsync_len - 1),
161 		     &par->regs->line_length);
162 
163 	switch (info->var.bits_per_pixel) {
164 	case 8:
165 		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
166 		func = 1;
167 		break;
168 	case 16:
169 		info->fix.visual = FB_VISUAL_TRUECOLOR;
170 		func = 2;
171 		break;
172 	case 24:
173 	case 32:
174 		info->fix.visual = FB_VISUAL_TRUECOLOR;
175 		func = 3;
176 		break;
177 	default:
178 		return -EINVAL;
179 	}
180 
181 	__raw_writel((par->clk_sel << 6) | (func << 4) | 1,
182 		     &par->regs->status);
183 
184 	info->fix.line_length = (info->var.xres_virtual*info->var.bits_per_pixel)/8;
185 	return 0;
186 }
187 
188 static int grvga_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info)
189 {
190 	struct grvga_par *par;
191 	par = info->par;
192 
193 	if (regno >= 256)	/* Size of CLUT */
194 		return -EINVAL;
195 
196 	if (info->var.grayscale) {
197 		/* grayscale = 0.30*R + 0.59*G + 0.11*B */
198 		red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
199 	}
200 
201 
202 
203 #define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)
204 
205 	red    = CNVT_TOHW(red,   info->var.red.length);
206 	green  = CNVT_TOHW(green, info->var.green.length);
207 	blue   = CNVT_TOHW(blue,  info->var.blue.length);
208 	transp = CNVT_TOHW(transp, info->var.transp.length);
209 
210 #undef CNVT_TOHW
211 
212 	/* In PSEUDOCOLOR we use the hardware CLUT */
213 	if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR)
214 		__raw_writel((regno << 24) | (red << 16) | (green << 8) | blue,
215 			     &par->regs->clut);
216 
217 	/* Truecolor uses the pseudo palette */
218 	else if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
219 		u32 v;
220 		if (regno >= 16)
221 			return -EINVAL;
222 
223 
224 		v =     (red    << info->var.red.offset)   |
225 			(green  << info->var.green.offset) |
226 			(blue   << info->var.blue.offset)  |
227 			(transp << info->var.transp.offset);
228 
229 		((u32 *) (info->pseudo_palette))[regno] = v;
230 	}
231 	return 0;
232 }
233 
234 static int grvga_pan_display(struct fb_var_screeninfo *var,
235 			     struct fb_info *info)
236 {
237 	struct grvga_par *par = info->par;
238 	struct fb_fix_screeninfo *fix = &info->fix;
239 	u32 base_addr;
240 
241 	if (var->xoffset != 0)
242 		return -EINVAL;
243 
244 	base_addr = fix->smem_start + (var->yoffset * fix->line_length);
245 	base_addr &= ~3UL;
246 
247 	/* Set framebuffer base address  */
248 	__raw_writel(base_addr,
249 		     &par->regs->fb_pos);
250 
251 	return 0;
252 }
253 
254 static struct fb_ops grvga_ops = {
255 	.owner          = THIS_MODULE,
256 	.fb_check_var   = grvga_check_var,
257 	.fb_set_par	= grvga_set_par,
258 	.fb_setcolreg   = grvga_setcolreg,
259 	.fb_pan_display = grvga_pan_display,
260 	.fb_fillrect	= cfb_fillrect,
261 	.fb_copyarea	= cfb_copyarea,
262 	.fb_imageblit	= cfb_imageblit
263 };
264 
265 static int grvga_parse_custom(char *options,
266 			      struct fb_var_screeninfo *screendata)
267 {
268 	char *this_opt;
269 	int count = 0;
270 	if (!options || !*options)
271 		return -1;
272 
273 	while ((this_opt = strsep(&options, " ")) != NULL) {
274 		if (!*this_opt)
275 			continue;
276 
277 		switch (count) {
278 		case 0:
279 			screendata->pixclock = simple_strtoul(this_opt, NULL, 0);
280 			count++;
281 			break;
282 		case 1:
283 			screendata->xres = screendata->xres_virtual = simple_strtoul(this_opt, NULL, 0);
284 			count++;
285 			break;
286 		case 2:
287 			screendata->right_margin = simple_strtoul(this_opt, NULL, 0);
288 			count++;
289 			break;
290 		case 3:
291 			screendata->hsync_len = simple_strtoul(this_opt, NULL, 0);
292 			count++;
293 			break;
294 		case 4:
295 			screendata->left_margin = simple_strtoul(this_opt, NULL, 0);
296 			count++;
297 			break;
298 		case 5:
299 			screendata->yres = screendata->yres_virtual = simple_strtoul(this_opt, NULL, 0);
300 			count++;
301 			break;
302 		case 6:
303 			screendata->lower_margin = simple_strtoul(this_opt, NULL, 0);
304 			count++;
305 			break;
306 		case 7:
307 			screendata->vsync_len = simple_strtoul(this_opt, NULL, 0);
308 			count++;
309 			break;
310 		case 8:
311 			screendata->upper_margin = simple_strtoul(this_opt, NULL, 0);
312 			count++;
313 			break;
314 		case 9:
315 			screendata->bits_per_pixel = simple_strtoul(this_opt, NULL, 0);
316 			count++;
317 			break;
318 		default:
319 			return -1;
320 		}
321 	}
322 	screendata->activate  = FB_ACTIVATE_NOW;
323 	screendata->vmode     = FB_VMODE_NONINTERLACED;
324 	return 0;
325 }
326 
327 static int grvga_probe(struct platform_device *dev)
328 {
329 	struct fb_info *info;
330 	int retval = -ENOMEM;
331 	unsigned long virtual_start;
332 	unsigned long grvga_fix_addr = 0;
333 	unsigned long physical_start = 0;
334 	unsigned long grvga_mem_size = 0;
335 	struct grvga_par *par = NULL;
336 	char *options = NULL, *mode_opt = NULL;
337 
338 	info = framebuffer_alloc(sizeof(struct grvga_par), &dev->dev);
339 	if (!info) {
340 		dev_err(&dev->dev, "framebuffer_alloc failed\n");
341 		return -ENOMEM;
342 	}
343 
344 	/* Expecting: "grvga: modestring, [addr:<framebuffer physical address>], [size:<framebuffer size>]
345 	 *
346 	 * If modestring is custom:<custom mode string> we parse the string which then contains all videoparameters
347 	 * If address is left out, we allocate memory,
348 	 * if size is left out we only allocate enough to support the given mode.
349 	 */
350 	if (fb_get_options("grvga", &options)) {
351 		retval = -ENODEV;
352 		goto free_fb;
353 	}
354 
355 	if (!options || !*options)
356 		options =  "640x480-8@60";
357 
358 	while (1) {
359 		char *this_opt = strsep(&options, ",");
360 
361 		if (!this_opt)
362 			break;
363 
364 		if (!strncmp(this_opt, "custom", 6)) {
365 			if (grvga_parse_custom(this_opt, &info->var) < 0) {
366 				dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
367 				retval = -EINVAL;
368 				goto free_fb;
369 			}
370 		} else if (!strncmp(this_opt, "addr", 4))
371 			grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
372 		else if (!strncmp(this_opt, "size", 4))
373 			grvga_mem_size = simple_strtoul(this_opt + 5, NULL, 0);
374 		else
375 			mode_opt = this_opt;
376 	}
377 
378 	par = info->par;
379 	info->fbops = &grvga_ops;
380 	info->fix = grvga_fix;
381 	info->pseudo_palette = par->color_palette;
382 	info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
383 	info->fix.smem_len = grvga_mem_size;
384 
385 	if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
386 		    resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
387 		dev_err(&dev->dev, "registers already mapped\n");
388 		retval = -EBUSY;
389 		goto free_fb;
390 	}
391 
392 	par->regs = of_ioremap(&dev->resource[0], 0,
393 			       resource_size(&dev->resource[0]),
394 			       "grlib-svgactrl regs");
395 
396 	if (!par->regs) {
397 		dev_err(&dev->dev, "failed to map registers\n");
398 		retval = -ENOMEM;
399 		goto free_fb;
400 	}
401 
402 	retval = fb_alloc_cmap(&info->cmap, 256, 0);
403 	if (retval < 0) {
404 		dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
405 		retval = -ENOMEM;
406 		goto unmap_regs;
407 	}
408 
409 	if (mode_opt) {
410 		retval = fb_find_mode(&info->var, info, mode_opt,
411 				      grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
412 		if (!retval || retval == 4) {
413 			retval = -EINVAL;
414 			goto dealloc_cmap;
415 		}
416 	}
417 
418 	if (!grvga_mem_size)
419 		grvga_mem_size = info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel/8;
420 
421 	if (grvga_fix_addr) {
422 		/* Got framebuffer base address from argument list */
423 
424 		physical_start = grvga_fix_addr;
425 
426 		if (!devm_request_mem_region(&dev->dev, physical_start,
427 					     grvga_mem_size, dev->name)) {
428 			dev_err(&dev->dev, "failed to request memory region\n");
429 			retval = -ENOMEM;
430 			goto dealloc_cmap;
431 		}
432 
433 		virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
434 
435 		if (!virtual_start) {
436 			dev_err(&dev->dev, "error mapping framebuffer memory\n");
437 			retval = -ENOMEM;
438 			goto dealloc_cmap;
439 		}
440 	} else {	/* Allocate frambuffer memory */
441 
442 		unsigned long page;
443 
444 		virtual_start = (unsigned long) __get_free_pages(GFP_DMA,
445 								 get_order(grvga_mem_size));
446 		if (!virtual_start) {
447 			dev_err(&dev->dev,
448 				"unable to allocate framebuffer memory (%lu bytes)\n",
449 				grvga_mem_size);
450 			retval = -ENOMEM;
451 			goto dealloc_cmap;
452 		}
453 
454 		physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
455 
456 		/* Set page reserved so that mmap will work. This is necessary
457 		 * since we'll be remapping normal memory.
458 		 */
459 		for (page = virtual_start;
460 		     page < PAGE_ALIGN(virtual_start + grvga_mem_size);
461 		     page += PAGE_SIZE) {
462 			SetPageReserved(virt_to_page(page));
463 		}
464 
465 		par->fb_alloced = 1;
466 	}
467 
468 	memset((unsigned long *) virtual_start, 0, grvga_mem_size);
469 
470 	info->screen_base = (char __iomem *) virtual_start;
471 	info->fix.smem_start = physical_start;
472 	info->fix.smem_len   = grvga_mem_size;
473 
474 	dev_set_drvdata(&dev->dev, info);
475 
476 	dev_info(&dev->dev,
477 		 "Aeroflex Gaisler framebuffer device (fb%d), %dx%d-%d, using %luK of video memory @ %p\n",
478 		 info->node, info->var.xres, info->var.yres, info->var.bits_per_pixel,
479 		 grvga_mem_size >> 10, info->screen_base);
480 
481 	retval = register_framebuffer(info);
482 	if (retval < 0) {
483 		dev_err(&dev->dev, "failed to register framebuffer\n");
484 		goto free_mem;
485 	}
486 
487 	__raw_writel(physical_start, &par->regs->fb_pos);
488 	__raw_writel(__raw_readl(&par->regs->status) | 1,  /* Enable framebuffer */
489 		     &par->regs->status);
490 
491 	return 0;
492 
493 free_mem:
494 	if (grvga_fix_addr)
495 		iounmap((void *)virtual_start);
496 	else
497 		kfree((void *)virtual_start);
498 dealloc_cmap:
499 	fb_dealloc_cmap(&info->cmap);
500 unmap_regs:
501 	of_iounmap(&dev->resource[0], par->regs,
502 		   resource_size(&dev->resource[0]));
503 free_fb:
504 	framebuffer_release(info);
505 
506 	return retval;
507 }
508 
509 static int grvga_remove(struct platform_device *device)
510 {
511 	struct fb_info *info = dev_get_drvdata(&device->dev);
512 	struct grvga_par *par;
513 
514 	if (info) {
515 		par = info->par;
516 		unregister_framebuffer(info);
517 		fb_dealloc_cmap(&info->cmap);
518 
519 		of_iounmap(&device->resource[0], par->regs,
520 			   resource_size(&device->resource[0]));
521 
522 		if (!par->fb_alloced)
523 			iounmap(info->screen_base);
524 		else
525 			kfree((void *)info->screen_base);
526 
527 		framebuffer_release(info);
528 	}
529 
530 	return 0;
531 }
532 
533 static struct of_device_id svgactrl_of_match[] = {
534 	{
535 		.name = "GAISLER_SVGACTRL",
536 	},
537 	{
538 		.name = "01_063",
539 	},
540 	{},
541 };
542 MODULE_DEVICE_TABLE(of, svgactrl_of_match);
543 
544 static struct platform_driver grvga_driver = {
545 	.driver = {
546 		.name = "grlib-svgactrl",
547 		.of_match_table = svgactrl_of_match,
548 	},
549 	.probe		= grvga_probe,
550 	.remove		= grvga_remove,
551 };
552 
553 module_platform_driver(grvga_driver);
554 
555 MODULE_LICENSE("GPL");
556 MODULE_AUTHOR("Aeroflex Gaisler");
557 MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");
558