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
34struct 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
45struct 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
53static 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
73static 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
83static 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
149static 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
193static 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
239static 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
259static 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
270static 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
332static 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
498free_mem:
499	if (grvga_fix_addr)
500		iounmap((void *)virtual_start);
501	else
502		kfree((void *)virtual_start);
503dealloc_cmap:
504	fb_dealloc_cmap(&info->cmap);
505unmap_regs:
506	of_iounmap(&dev->resource[0], par->regs,
507		   resource_size(&dev->resource[0]));
508free_fb:
509	framebuffer_release(info);
510
511	return retval;
512}
513
514static 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
538static struct of_device_id svgactrl_of_match[] = {
539	{
540		.name = "GAISLER_SVGACTRL",
541	},
542	{
543		.name = "01_063",
544	},
545	{},
546};
547MODULE_DEVICE_TABLE(of, svgactrl_of_match);
548
549static 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
558module_platform_driver(grvga_driver);
559
560MODULE_LICENSE("GPL");
561MODULE_AUTHOR("Aeroflex Gaisler");
562MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");
563