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 * https://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
grvga_check_var(struct fb_var_screeninfo * var,struct fb_info * info)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
grvga_set_par(struct fb_info * info)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
grvga_setcolreg(unsigned regno,unsigned red,unsigned green,unsigned blue,unsigned transp,struct fb_info * info)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
grvga_pan_display(struct fb_var_screeninfo * var,struct fb_info * info)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 const 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
grvga_parse_custom(char * options,struct fb_var_screeninfo * screendata)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
grvga_probe(struct platform_device * dev)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 return -ENOMEM;
341
342 /* Expecting: "grvga: modestring, [addr:<framebuffer physical address>], [size:<framebuffer size>]
343 *
344 * If modestring is custom:<custom mode string> we parse the string which then contains all videoparameters
345 * If address is left out, we allocate memory,
346 * if size is left out we only allocate enough to support the given mode.
347 */
348 if (fb_get_options("grvga", &options)) {
349 retval = -ENODEV;
350 goto free_fb;
351 }
352
353 if (!options || !*options)
354 options = "640x480-8@60";
355
356 while (1) {
357 char *this_opt = strsep(&options, ",");
358
359 if (!this_opt)
360 break;
361
362 if (!strncmp(this_opt, "custom", 6)) {
363 if (grvga_parse_custom(this_opt, &info->var) < 0) {
364 dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
365 retval = -EINVAL;
366 goto free_fb;
367 }
368 } else if (!strncmp(this_opt, "addr", 4))
369 grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
370 else if (!strncmp(this_opt, "size", 4))
371 grvga_mem_size = simple_strtoul(this_opt + 5, NULL, 0);
372 else
373 mode_opt = this_opt;
374 }
375
376 par = info->par;
377 info->fbops = &grvga_ops;
378 info->fix = grvga_fix;
379 info->pseudo_palette = par->color_palette;
380 info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
381 info->fix.smem_len = grvga_mem_size;
382
383 if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
384 resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
385 dev_err(&dev->dev, "registers already mapped\n");
386 retval = -EBUSY;
387 goto free_fb;
388 }
389
390 par->regs = of_ioremap(&dev->resource[0], 0,
391 resource_size(&dev->resource[0]),
392 "grlib-svgactrl regs");
393
394 if (!par->regs) {
395 dev_err(&dev->dev, "failed to map registers\n");
396 retval = -ENOMEM;
397 goto free_fb;
398 }
399
400 retval = fb_alloc_cmap(&info->cmap, 256, 0);
401 if (retval < 0) {
402 dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
403 retval = -ENOMEM;
404 goto unmap_regs;
405 }
406
407 if (mode_opt) {
408 retval = fb_find_mode(&info->var, info, mode_opt,
409 grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
410 if (!retval || retval == 4) {
411 retval = -EINVAL;
412 goto dealloc_cmap;
413 }
414 }
415
416 if (!grvga_mem_size)
417 grvga_mem_size = info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel/8;
418
419 if (grvga_fix_addr) {
420 /* Got framebuffer base address from argument list */
421
422 physical_start = grvga_fix_addr;
423
424 if (!devm_request_mem_region(&dev->dev, physical_start,
425 grvga_mem_size, dev->name)) {
426 dev_err(&dev->dev, "failed to request memory region\n");
427 retval = -ENOMEM;
428 goto dealloc_cmap;
429 }
430
431 virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
432
433 if (!virtual_start) {
434 dev_err(&dev->dev, "error mapping framebuffer memory\n");
435 retval = -ENOMEM;
436 goto dealloc_cmap;
437 }
438 } else { /* Allocate frambuffer memory */
439
440 unsigned long page;
441
442 virtual_start = (unsigned long) __get_free_pages(GFP_DMA,
443 get_order(grvga_mem_size));
444 if (!virtual_start) {
445 dev_err(&dev->dev,
446 "unable to allocate framebuffer memory (%lu bytes)\n",
447 grvga_mem_size);
448 retval = -ENOMEM;
449 goto dealloc_cmap;
450 }
451
452 physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
453
454 /* Set page reserved so that mmap will work. This is necessary
455 * since we'll be remapping normal memory.
456 */
457 for (page = virtual_start;
458 page < PAGE_ALIGN(virtual_start + grvga_mem_size);
459 page += PAGE_SIZE) {
460 SetPageReserved(virt_to_page(page));
461 }
462
463 par->fb_alloced = 1;
464 }
465
466 memset((unsigned long *) virtual_start, 0, grvga_mem_size);
467
468 info->screen_base = (char __iomem *) virtual_start;
469 info->fix.smem_start = physical_start;
470 info->fix.smem_len = grvga_mem_size;
471
472 dev_set_drvdata(&dev->dev, info);
473
474 dev_info(&dev->dev,
475 "Aeroflex Gaisler framebuffer device (fb%d), %dx%d-%d, using %luK of video memory @ %p\n",
476 info->node, info->var.xres, info->var.yres, info->var.bits_per_pixel,
477 grvga_mem_size >> 10, info->screen_base);
478
479 retval = register_framebuffer(info);
480 if (retval < 0) {
481 dev_err(&dev->dev, "failed to register framebuffer\n");
482 goto free_mem;
483 }
484
485 __raw_writel(physical_start, &par->regs->fb_pos);
486 __raw_writel(__raw_readl(&par->regs->status) | 1, /* Enable framebuffer */
487 &par->regs->status);
488
489 return 0;
490
491 free_mem:
492 if (grvga_fix_addr)
493 iounmap((void *)virtual_start);
494 else
495 kfree((void *)virtual_start);
496 dealloc_cmap:
497 fb_dealloc_cmap(&info->cmap);
498 unmap_regs:
499 of_iounmap(&dev->resource[0], par->regs,
500 resource_size(&dev->resource[0]));
501 free_fb:
502 framebuffer_release(info);
503
504 return retval;
505 }
506
grvga_remove(struct platform_device * device)507 static int grvga_remove(struct platform_device *device)
508 {
509 struct fb_info *info = dev_get_drvdata(&device->dev);
510 struct grvga_par *par;
511
512 if (info) {
513 par = info->par;
514 unregister_framebuffer(info);
515 fb_dealloc_cmap(&info->cmap);
516
517 of_iounmap(&device->resource[0], par->regs,
518 resource_size(&device->resource[0]));
519
520 if (!par->fb_alloced)
521 iounmap(info->screen_base);
522 else
523 kfree((void *)info->screen_base);
524
525 framebuffer_release(info);
526 }
527
528 return 0;
529 }
530
531 static struct of_device_id svgactrl_of_match[] = {
532 {
533 .name = "GAISLER_SVGACTRL",
534 },
535 {
536 .name = "01_063",
537 },
538 {},
539 };
540 MODULE_DEVICE_TABLE(of, svgactrl_of_match);
541
542 static struct platform_driver grvga_driver = {
543 .driver = {
544 .name = "grlib-svgactrl",
545 .of_match_table = svgactrl_of_match,
546 },
547 .probe = grvga_probe,
548 .remove = grvga_remove,
549 };
550
551 module_platform_driver(grvga_driver);
552
553 MODULE_LICENSE("GPL");
554 MODULE_AUTHOR("Aeroflex Gaisler");
555 MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");
556