1/*
2 * drivers/video/ubicom32vfb.c
3 *	Ubicom32 virtual frame buffer driver
4 *
5 * (C) Copyright 2009, Ubicom, Inc.
6 *
7 * This file is part of the Ubicom32 Linux Kernel Port.
8 *
9 * The Ubicom32 Linux Kernel Port is free software: you can redistribute
10 * it and/or modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation, either version 2 of the
12 * License, or (at your option) any later version.
13 *
14 * The Ubicom32 Linux Kernel Port is distributed in the hope that it
15 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
16 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
17 * the GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with the Ubicom32 Linux Kernel Port.  If not,
21 * see <http://www.gnu.org/licenses/>.
22 */
23
24/*
25 * This driver was based on skeletonfb.c, Skeleton for a frame buffer device by
26 * Geert Uytterhoeven.
27 */
28
29#include <linux/device.h>
30#include <linux/module.h>
31#include <linux/kernel.h>
32#include <linux/version.h>
33#include <linux/errno.h>
34#include <linux/string.h>
35#include <linux/mm.h>
36#include <linux/fb.h>
37#include <linux/init.h>
38#include <linux/dma-mapping.h>
39#include <linux/platform_device.h>
40#include <linux/device.h>
41#include <linux/uaccess.h>
42
43#define DRIVER_NAME		"ubicom32vfb"
44#define DRIVER_DESCRIPTION	"Ubicom32 virtual frame buffer driver"
45
46#define PALETTE_ENTRIES_NO	16
47
48/*
49 * Option variables
50 *
51 * vram_size:	VRAM size in kilobytes, subject to alignment
52 */
53static int vram_size = 0;
54module_param(vram_size, int, 0);
55MODULE_PARM_DESC(vram_size, "VRAM size, in kilobytes to allocate, should be at least the size of one screen, subject to alignment");
56
57static int xres = 320;
58module_param(xres, int, 0);
59MODULE_PARM_DESC(xres, "x (horizontal) resolution");
60
61static int yres = 240;
62module_param(yres, int, 0);
63MODULE_PARM_DESC(yres, "y (vertical) resolution");
64
65static int bgr = 0;
66module_param(bgr, int, 0);
67MODULE_PARM_DESC(bgr, "display is BGR (Blue is MSB)");
68
69#define BITS_PER_PIXEL	16
70
71/*
72 * Buffer alignment, must not be 0
73 */
74#define UBICOM32VFB_ALIGNMENT 4
75
76/*
77 * fb_fix_screeninfo defines the non-changeable properties of the VDC, depending on what mode it is in.
78 */
79static struct fb_fix_screeninfo ubicom32vfb_fix = {
80	.id =		"Ubicom32",
81	.type =		FB_TYPE_PACKED_PIXELS,
82	.visual =	FB_VISUAL_TRUECOLOR,
83	.accel =	FB_ACCEL_UBICOM32_VFB,
84};
85
86/*
87 * Filled in at probe time when we find out what the hardware supports
88 */
89static struct fb_var_screeninfo ubicom32vfb_var;
90
91/*
92 * Private data structure
93 */
94struct ubicom32vfb_drvdata {
95	struct fb_info			*fbinfo;
96	bool				cmap_alloc;
97
98	/*
99	 * The address of the framebuffer in memory
100	 */
101	void				*fb;
102	void				*fb_aligned;
103
104	/*
105	 * Total size of vram including alignment allowance
106	 */
107	u32				total_vram_size;
108
109	/*
110	 * Fake palette of 16 colors
111	 */
112	u32				pseudo_palette[PALETTE_ENTRIES_NO];
113};
114
115static struct platform_device *ubicom32vfb_platform_device;
116
117/*
118 * ubicom32vfb_pan_display
119 *	Pans the display to a given location.  Supports only y direction panning.
120 */
121static int ubicom32vfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *fbi)
122{
123	struct ubicom32vfb_drvdata *ud = (struct ubicom32vfb_drvdata *)fbi->par;
124	void *new_addr;
125
126	/*
127	 * Get the last y line that would be displayed.  Since we don't support YWRAP,
128	 * it must be less than our virtual y size.
129	 */
130	u32 lasty = var->yoffset + var->yres;
131	if (lasty > fbi->var.yres_virtual) {
132		/*
133		 * We would fall off the end of our frame buffer if we panned here.
134		 */
135		return -EINVAL;
136	}
137
138	if (var->xoffset) {
139		/*
140		 * We don't support panning in the x direction
141		 */
142		return -EINVAL;
143	}
144
145	/*
146	 * Everything looks sane, go ahead and pan
147	 *
148	 * We have to calculate a new address for the VDC to look at
149	 */
150	new_addr = ud->fb_aligned + (var->yoffset * fbi->fix.line_length);
151
152	return 0;
153}
154
155/*
156 * ubicom32vfb_setcolreg
157 *	Sets a color in our virtual palette
158 */
159static int ubicom32vfb_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *fbi)
160{
161	u32 *palette = fbi->pseudo_palette;
162
163	if (regno >= PALETTE_ENTRIES_NO) {
164		return -EINVAL;
165	}
166
167	/*
168	 * We only use 8 bits from each color
169	 */
170	red >>= 8;
171	green >>= 8;
172	blue >>= 8;
173
174	/*
175	 * Convert any grayscale values
176	 */
177	if (fbi->var.grayscale) {
178		u16 gray = red + green + blue;
179		gray += (gray >> 2) + (gray >> 3) - (gray >> 7);
180		gray >>= 2;
181		if (gray > 255) {
182			gray = 255;
183		}
184		red = gray;
185		blue = gray;
186		green = gray;
187	}
188
189	palette[regno] = (red << fbi->var.red.offset) | (green << fbi->var.green.offset) |
190			 (blue << fbi->var.blue.offset);
191
192	return 0;
193}
194
195/*
196 * ubicom32vfb_mmap
197 */
198static int ubicom32vfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
199{
200	struct ubicom32vfb_drvdata *ud = (struct ubicom32vfb_drvdata *)info->par;
201
202	vma->vm_start = (unsigned long)(ud->fb_aligned);
203
204	vma->vm_end = vma->vm_start + info->fix.smem_len;
205
206	/* For those who don't understand how mmap works, go read
207	 *   Documentation/nommu-mmap.txt.
208	 * For those that do, you will know that the VM_MAYSHARE flag
209	 * must be set in the vma->vm_flags structure on noMMU
210	 *   Other flags can be set, and are documented in
211	 *   include/linux/mm.h
212	 */
213
214	vma->vm_flags |=  VM_MAYSHARE | VM_SHARED;
215
216	return 0;
217}
218
219/*
220 * ubicom32vfb_check_var
221 *	Check the var, tweak it but don't change operational parameters.
222 */
223static int ubicom32vfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
224{
225	struct ubicom32vfb_drvdata *ud = (struct ubicom32vfb_drvdata *)info->par;
226	u32 line_size = var->xres * (BITS_PER_PIXEL / 8);
227
228	/*
229	 * See if we can handle this bpp
230	 */
231	if (var->bits_per_pixel > BITS_PER_PIXEL) {
232		return -EINVAL;
233	}
234	var->bits_per_pixel = BITS_PER_PIXEL;
235
236	/*
237	 * See if we have enough memory to handle this resolution
238	 */
239	if ((line_size * var->yres * BITS_PER_PIXEL / 8) > ud->total_vram_size) {
240		return -EINVAL;
241	}
242
243	var->xres_virtual = var->xres;
244	var->yres_virtual = ud->total_vram_size / line_size;
245
246	var->red.length = 5;
247	var->green.length = 6;
248	var->green.offset = 5;
249	var->blue.length = 5;
250	var->transp.offset = var->transp.length = 0;
251
252	if (bgr) {
253		var->red.offset = 0;
254		var->blue.offset = 11;
255	} else {
256		var->red.offset = 11;
257		var->blue.offset = 0;
258	}
259
260	var->nonstd = 0;
261	var->height = -1;
262	var->width = -1;
263	var->vmode = FB_VMODE_NONINTERLACED;
264	var->sync = 0;
265
266	return 0;
267}
268
269/*
270 * ubicom32vfb_set_par
271 *	Set the video mode according to info->var
272 */
273static int ubicom32vfb_set_par(struct fb_info *info)
274{
275	/*
276	 * Anything changed?
277	 */
278	if ((xres == info->var.xres) && (yres == info->var.yres)) {
279		return 0;
280	}
281
282	/*
283	 * Implement changes
284	 */
285	xres = info->var.xres;
286	yres = info->var.yres;
287	info->fix.visual = FB_VISUAL_TRUECOLOR;
288	info->fix.xpanstep = 0;
289	info->fix.ypanstep = 1;
290	info->fix.line_length = xres * (BITS_PER_PIXEL / 8);
291
292	return 0;
293}
294
295/*
296 * ubicom32vfb_ops
297 *	List of supported operations
298 */
299static struct fb_ops ubicom32vfb_ops =
300{
301	.owner			= THIS_MODULE,
302	.fb_pan_display		= ubicom32vfb_pan_display,
303	.fb_setcolreg		= ubicom32vfb_setcolreg,
304	.fb_mmap		= ubicom32vfb_mmap,
305	.fb_check_var		= ubicom32vfb_check_var,
306	.fb_set_par		= ubicom32vfb_set_par,
307	.fb_fillrect		= cfb_fillrect,
308	.fb_copyarea		= cfb_copyarea,
309	.fb_imageblit		= cfb_imageblit,
310};
311
312/*
313 * ubicom32vfb_release
314 */
315static int ubicom32vfb_release(struct device *dev)
316{
317	struct ubicom32vfb_drvdata *ud = dev_get_drvdata(dev);
318
319	unregister_framebuffer(ud->fbinfo);
320
321	if (ud->cmap_alloc) {
322		fb_dealloc_cmap(&ud->fbinfo->cmap);
323	}
324
325	if (ud->fb) {
326		kfree(ud->fb);
327	}
328
329	framebuffer_release(ud->fbinfo);
330	dev_set_drvdata(dev, NULL);
331
332	return 0;
333}
334
335/*
336 * ubicom32vfb_platform_probe
337 */
338static int __init ubicom32vfb_platform_probe(struct platform_device *pdev)
339{
340	struct ubicom32vfb_drvdata *ud;
341	struct fb_info *fbinfo;
342	int rc;
343	size_t fbsize;
344	struct device *dev = &pdev->dev;
345	int offset;
346
347	/*
348	 * This is the minimum VRAM size
349	 */
350	fbsize = xres * yres * 2;
351	if (!vram_size) {
352		vram_size = (fbsize + 1023) / 1024;
353	} else {
354		if (fbsize > (vram_size * 1024)) {
355			dev_err(dev, "Not enough VRAM for display, need >= %u bytes\n", fbsize);
356			return -ENOMEM; // should be ebadparam?
357		}
358	}
359
360	/*
361	 * Allocate the framebuffer instance + our private data
362	 */
363	fbinfo = framebuffer_alloc(sizeof(struct ubicom32vfb_drvdata), &pdev->dev);
364	if (!fbinfo) {
365		dev_err(dev, "Not enough memory to allocate instance.\n");
366		return -ENOMEM;
367	}
368
369	/*
370	 * Fill in our private data.
371	 */
372	ud = (struct ubicom32vfb_drvdata *)fbinfo->par;
373	ud->fbinfo = fbinfo;
374	dev_set_drvdata(dev, ud);
375
376	/*
377	 * Allocate and align the requested amount of VRAM
378	 */
379	ud->total_vram_size = (vram_size * 1024) + UBICOM32VFB_ALIGNMENT;
380	ud->fb = kmalloc(ud->total_vram_size, GFP_KERNEL);
381	if (ud->fb == NULL) {
382		dev_err(dev, "Couldn't allocate VRAM\n");
383		rc = -ENOMEM;
384		goto fail;
385	}
386
387	offset = (u32_t)ud->fb & (UBICOM32VFB_ALIGNMENT - 1);
388	if (!offset) {
389		ud->fb_aligned = ud->fb;
390	} else {
391		offset =  UBICOM32VFB_ALIGNMENT - offset;
392		ud->fb_aligned = ud->fb + offset;
393	}
394
395	/*
396	 * Clear the entire frame buffer
397	 */
398	memset(ud->fb_aligned, 0, vram_size * 1024);
399
400	/*
401	 * Fill in the fb_var_screeninfo structure
402	 */
403	memset(&ubicom32vfb_var, 0, sizeof(ubicom32vfb_var));
404	ubicom32vfb_var.bits_per_pixel = BITS_PER_PIXEL;
405	ubicom32vfb_var.red.length = 5;
406	ubicom32vfb_var.green.length = 6;
407	ubicom32vfb_var.green.offset = 5;
408	ubicom32vfb_var.blue.length = 5;
409	ubicom32vfb_var.activate = FB_ACTIVATE_NOW;
410
411	if (bgr) {
412		ubicom32vfb_var.red.offset = 0;
413		ubicom32vfb_var.blue.offset = 11;
414	} else {
415		ubicom32vfb_var.red.offset = 11;
416		ubicom32vfb_var.blue.offset = 0;
417	}
418
419	/*
420	 * Fill in the fb_info structure
421	 */
422	ud->fbinfo->device = dev;
423	ud->fbinfo->screen_base = (void *)ud->fb_aligned;
424	ud->fbinfo->fbops = &ubicom32vfb_ops;
425	ud->fbinfo->fix = ubicom32vfb_fix;
426	ud->fbinfo->fix.smem_start = (u32)ud->fb_aligned;
427	ud->fbinfo->fix.smem_len = vram_size * 1024;
428	ud->fbinfo->fix.line_length = xres * 2;
429	ud->fbinfo->fix.mmio_start = (u32)ud;
430	ud->fbinfo->fix.mmio_len = sizeof(struct ubicom32vfb_drvdata);
431
432	/*
433	 * We support panning in the y direction only
434	 */
435	ud->fbinfo->fix.xpanstep = 0;
436	ud->fbinfo->fix.ypanstep = 1;
437
438	ud->fbinfo->pseudo_palette = ud->pseudo_palette;
439	ud->fbinfo->flags = FBINFO_DEFAULT;
440	ud->fbinfo->var = ubicom32vfb_var;
441	ud->fbinfo->var.xres = xres;
442	ud->fbinfo->var.yres = yres;
443
444	/*
445	 * We cannot pan in the X direction, so xres_virtual is xres
446	 * We can pan in the Y direction, so yres_virtual is vram_size / ud->fbinfo->fix.line_length
447	 */
448	ud->fbinfo->var.xres_virtual = xres;
449	ud->fbinfo->var.yres_virtual = (vram_size * 1024) / ud->fbinfo->fix.line_length;
450
451	/*
452	 * Allocate a color map
453	 */
454	rc = fb_alloc_cmap(&ud->fbinfo->cmap, PALETTE_ENTRIES_NO, 0);
455	if (rc) {
456		dev_err(dev, "Fail to allocate colormap (%d entries)\n",
457			PALETTE_ENTRIES_NO);
458		goto fail;
459	}
460	ud->cmap_alloc = true;
461
462	/*
463	 * Register new frame buffer
464	 */
465	rc = register_framebuffer(ud->fbinfo);
466	if (rc) {
467		dev_err(dev, "Could not register frame buffer\n");
468		goto fail;
469	}
470
471	/*
472	 * Tell the log we are here
473	 */
474	dev_info(dev, "fbaddr=%p align=%p, size=%uKB screen(%ux%u) virt(%ux%u)\n",
475		ud->fb, ud->fb_aligned, vram_size, ud->fbinfo->var.xres, ud->fbinfo->var.yres,
476		ud->fbinfo->var.xres_virtual, ud->fbinfo->var.yres_virtual);
477
478	/*
479	 * Success
480	 */
481	return 0;
482
483fail:
484	ubicom32vfb_release(dev);
485	return rc;
486}
487
488/*
489 * ubicom32vfb_platform_remove
490 */
491static int ubicom32vfb_platform_remove(struct platform_device *pdev)
492{
493	dev_info(&(pdev->dev), "Ubicom32 FB Driver Remove\n");
494	return ubicom32vfb_release(&pdev->dev);
495}
496
497static struct platform_driver ubicom32vfb_platform_driver = {
498	.probe		= ubicom32vfb_platform_probe,
499	.remove		= ubicom32vfb_platform_remove,
500	.driver = {
501		.name = DRIVER_NAME,
502		.owner = THIS_MODULE,
503	},
504};
505
506#ifndef MODULE
507/*
508 * ubicom32vfb_setup
509 *	Process kernel boot options
510 */
511static int __init ubicom32vfb_setup(char *options)
512{
513	char *this_opt;
514
515	if (!options || !*options) {
516		return 0;
517	}
518
519	while ((this_opt = strsep(&options, ",")) != NULL) {
520		if (!*this_opt) {
521			continue;
522		}
523
524		if (!strncmp(this_opt, "vram_size=", 10)) {
525			vram_size = simple_strtoul(this_opt + 10, NULL, 0);
526			continue;
527		}
528
529		if (!strncmp(this_opt, "bgr=", 4)) {
530			bgr = simple_strtoul(this_opt + 4, NULL, 0);
531			continue;
532		}
533
534		if (!strncmp(this_opt, "xres=", 5)) {
535			xres = simple_strtoul(this_opt + 5, NULL, 0);
536			continue;
537		}
538
539		if (!strncmp(this_opt, "yres=", 5)) {
540			yres = simple_strtoul(this_opt + 5, NULL, 0);
541			continue;
542		}
543	}
544	return 0;
545}
546#endif /* MODULE */
547
548/*
549 * ubicom32vfb_init
550 */
551static int __devinit ubicom32vfb_init(void)
552{
553	int ret;
554
555#ifndef MODULE
556	/*
557	 * Get kernel boot options (in 'video=ubicom32vfb:<options>')
558	 */
559	char *option = NULL;
560
561	if (fb_get_options(DRIVER_NAME, &option)) {
562		return -ENODEV;
563	}
564	ubicom32vfb_setup(option);
565#endif /* MODULE */
566
567	ret = platform_driver_register(&ubicom32vfb_platform_driver);
568
569#ifdef CONFIG_FB_UBICOM32_VIRTUAL_NOAUTO
570	return ret;
571#else
572	if (!ret) {
573		ubicom32vfb_platform_device = platform_device_alloc(DRIVER_NAME, 0);
574
575		if (ubicom32vfb_platform_device)
576			ret = platform_device_add(ubicom32vfb_platform_device);
577		else
578			ret = -ENOMEM;
579
580		if (ret) {
581			platform_device_put(ubicom32vfb_platform_device);
582			platform_driver_unregister(&ubicom32vfb_platform_driver);
583		}
584	}
585
586	return ret;
587#endif
588}
589module_init(ubicom32vfb_init);
590
591/*
592 * ubicom32vfb_exit
593 */
594static void __exit ubicom32vfb_exit(void)
595{
596	platform_device_unregister(ubicom32vfb_platform_device);
597	platform_driver_unregister(&ubicom32vfb_platform_driver);
598}
599module_exit(ubicom32vfb_exit);
600
601MODULE_LICENSE("GPL");
602MODULE_AUTHOR("Patrick Tjin <@ubicom.com>");
603MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
604