1 | /* |
2 | * OpenCores VGA/LCD 2.0 core frame buffer driver |
3 | * |
4 | * Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson@saunalahti.fi |
5 | * |
6 | * This file is licensed under the terms of the GNU General Public License |
7 | * version 2. This program is licensed "as is" without any warranty of any |
8 | * kind, whether express or implied. |
9 | */ |
10 | |
11 | #include <linux/delay.h> |
12 | #include <linux/dma-mapping.h> |
13 | #include <linux/errno.h> |
14 | #include <linux/fb.h> |
15 | #include <linux/init.h> |
16 | #include <linux/io.h> |
17 | #include <linux/kernel.h> |
18 | #include <linux/mm.h> |
19 | #include <linux/module.h> |
20 | #include <linux/of.h> |
21 | #include <linux/platform_device.h> |
22 | #include <linux/string.h> |
23 | #include <linux/slab.h> |
24 | |
25 | /* OCFB register defines */ |
26 | #define OCFB_CTRL 0x000 |
27 | #define OCFB_STAT 0x004 |
28 | #define OCFB_HTIM 0x008 |
29 | #define OCFB_VTIM 0x00c |
30 | #define OCFB_HVLEN 0x010 |
31 | #define OCFB_VBARA 0x014 |
32 | #define OCFB_PALETTE 0x800 |
33 | |
34 | #define OCFB_CTRL_VEN 0x00000001 /* Video Enable */ |
35 | #define OCFB_CTRL_HIE 0x00000002 /* HSync Interrupt Enable */ |
36 | #define OCFB_CTRL_PC 0x00000800 /* 8-bit Pseudo Color Enable*/ |
37 | #define OCFB_CTRL_CD8 0x00000000 /* Color Depth 8 */ |
38 | #define OCFB_CTRL_CD16 0x00000200 /* Color Depth 16 */ |
39 | #define OCFB_CTRL_CD24 0x00000400 /* Color Depth 24 */ |
40 | #define OCFB_CTRL_CD32 0x00000600 /* Color Depth 32 */ |
41 | #define OCFB_CTRL_VBL1 0x00000000 /* Burst Length 1 */ |
42 | #define OCFB_CTRL_VBL2 0x00000080 /* Burst Length 2 */ |
43 | #define OCFB_CTRL_VBL4 0x00000100 /* Burst Length 4 */ |
44 | #define OCFB_CTRL_VBL8 0x00000180 /* Burst Length 8 */ |
45 | |
46 | #define PALETTE_SIZE 256 |
47 | |
48 | #define OCFB_NAME "OC VGA/LCD" |
49 | |
50 | static char *mode_option; |
51 | |
52 | static const struct fb_videomode default_mode = { |
53 | /* 640x480 @ 60 Hz, 31.5 kHz hsync */ |
54 | NULL, 60, 640, 480, 39721, 40, 24, 32, 11, 96, 2, |
55 | 0, FB_VMODE_NONINTERLACED |
56 | }; |
57 | |
58 | struct ocfb_dev { |
59 | struct fb_info info; |
60 | void __iomem *regs; |
61 | /* flag indicating whether the regs are little endian accessed */ |
62 | int little_endian; |
63 | /* Physical and virtual addresses of framebuffer */ |
64 | dma_addr_t fb_phys; |
65 | void __iomem *fb_virt; |
66 | u32 pseudo_palette[PALETTE_SIZE]; |
67 | }; |
68 | |
69 | #ifndef MODULE |
70 | static int __init ocfb_setup(char *options) |
71 | { |
72 | char *curr_opt; |
73 | |
74 | if (!options || !*options) |
75 | return 0; |
76 | |
77 | while ((curr_opt = strsep(&options, "," )) != NULL) { |
78 | if (!*curr_opt) |
79 | continue; |
80 | mode_option = curr_opt; |
81 | } |
82 | |
83 | return 0; |
84 | } |
85 | #endif |
86 | |
87 | static inline u32 ocfb_readreg(struct ocfb_dev *fbdev, loff_t offset) |
88 | { |
89 | if (fbdev->little_endian) |
90 | return ioread32(fbdev->regs + offset); |
91 | else |
92 | return ioread32be(fbdev->regs + offset); |
93 | } |
94 | |
95 | static void ocfb_writereg(struct ocfb_dev *fbdev, loff_t offset, u32 data) |
96 | { |
97 | if (fbdev->little_endian) |
98 | iowrite32(data, fbdev->regs + offset); |
99 | else |
100 | iowrite32be(data, fbdev->regs + offset); |
101 | } |
102 | |
103 | static int ocfb_setupfb(struct ocfb_dev *fbdev) |
104 | { |
105 | unsigned long bpp_config; |
106 | struct fb_var_screeninfo *var = &fbdev->info.var; |
107 | struct device *dev = fbdev->info.device; |
108 | u32 hlen; |
109 | u32 vlen; |
110 | |
111 | /* Disable display */ |
112 | ocfb_writereg(fbdev, OCFB_CTRL, data: 0); |
113 | |
114 | /* Register framebuffer address */ |
115 | fbdev->little_endian = 0; |
116 | ocfb_writereg(fbdev, OCFB_VBARA, data: fbdev->fb_phys); |
117 | |
118 | /* Detect endianess */ |
119 | if (ocfb_readreg(fbdev, OCFB_VBARA) != fbdev->fb_phys) { |
120 | fbdev->little_endian = 1; |
121 | ocfb_writereg(fbdev, OCFB_VBARA, data: fbdev->fb_phys); |
122 | } |
123 | |
124 | /* Horizontal timings */ |
125 | ocfb_writereg(fbdev, OCFB_HTIM, data: (var->hsync_len - 1) << 24 | |
126 | (var->left_margin - 1) << 16 | (var->xres - 1)); |
127 | |
128 | /* Vertical timings */ |
129 | ocfb_writereg(fbdev, OCFB_VTIM, data: (var->vsync_len - 1) << 24 | |
130 | (var->upper_margin - 1) << 16 | (var->yres - 1)); |
131 | |
132 | /* Total length of frame */ |
133 | hlen = var->left_margin + var->right_margin + var->hsync_len + |
134 | var->xres; |
135 | |
136 | vlen = var->upper_margin + var->lower_margin + var->vsync_len + |
137 | var->yres; |
138 | |
139 | ocfb_writereg(fbdev, OCFB_HVLEN, data: (hlen - 1) << 16 | (vlen - 1)); |
140 | |
141 | bpp_config = OCFB_CTRL_CD8; |
142 | switch (var->bits_per_pixel) { |
143 | case 8: |
144 | if (!var->grayscale) |
145 | bpp_config |= OCFB_CTRL_PC; /* enable palette */ |
146 | break; |
147 | |
148 | case 16: |
149 | bpp_config |= OCFB_CTRL_CD16; |
150 | break; |
151 | |
152 | case 24: |
153 | bpp_config |= OCFB_CTRL_CD24; |
154 | break; |
155 | |
156 | case 32: |
157 | bpp_config |= OCFB_CTRL_CD32; |
158 | break; |
159 | |
160 | default: |
161 | dev_err(dev, "no bpp specified\n" ); |
162 | break; |
163 | } |
164 | |
165 | /* maximum (8) VBL (video memory burst length) */ |
166 | bpp_config |= OCFB_CTRL_VBL8; |
167 | |
168 | /* Enable output */ |
169 | ocfb_writereg(fbdev, OCFB_CTRL, data: (OCFB_CTRL_VEN | bpp_config)); |
170 | |
171 | return 0; |
172 | } |
173 | |
174 | static int ocfb_setcolreg(unsigned regno, unsigned red, unsigned green, |
175 | unsigned blue, unsigned transp, |
176 | struct fb_info *info) |
177 | { |
178 | struct ocfb_dev *fbdev = (struct ocfb_dev *)info->par; |
179 | u32 color; |
180 | |
181 | if (regno >= info->cmap.len) { |
182 | dev_err(info->device, "regno >= cmap.len\n" ); |
183 | return 1; |
184 | } |
185 | |
186 | if (info->var.grayscale) { |
187 | /* grayscale = 0.30*R + 0.59*G + 0.11*B */ |
188 | red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8; |
189 | } |
190 | |
191 | red >>= (16 - info->var.red.length); |
192 | green >>= (16 - info->var.green.length); |
193 | blue >>= (16 - info->var.blue.length); |
194 | transp >>= (16 - info->var.transp.length); |
195 | |
196 | if (info->var.bits_per_pixel == 8 && !info->var.grayscale) { |
197 | regno <<= 2; |
198 | color = (red << 16) | (green << 8) | blue; |
199 | ocfb_writereg(fbdev, OCFB_PALETTE + regno, data: color); |
200 | } else { |
201 | ((u32 *)(info->pseudo_palette))[regno] = |
202 | (red << info->var.red.offset) | |
203 | (green << info->var.green.offset) | |
204 | (blue << info->var.blue.offset) | |
205 | (transp << info->var.transp.offset); |
206 | } |
207 | |
208 | return 0; |
209 | } |
210 | |
211 | static int ocfb_init_fix(struct ocfb_dev *fbdev) |
212 | { |
213 | struct fb_var_screeninfo *var = &fbdev->info.var; |
214 | struct fb_fix_screeninfo *fix = &fbdev->info.fix; |
215 | |
216 | strcpy(p: fix->id, OCFB_NAME); |
217 | |
218 | fix->line_length = var->xres * var->bits_per_pixel/8; |
219 | fix->smem_len = fix->line_length * var->yres; |
220 | fix->type = FB_TYPE_PACKED_PIXELS; |
221 | |
222 | if (var->bits_per_pixel == 8 && !var->grayscale) |
223 | fix->visual = FB_VISUAL_PSEUDOCOLOR; |
224 | else |
225 | fix->visual = FB_VISUAL_TRUECOLOR; |
226 | |
227 | return 0; |
228 | } |
229 | |
230 | static int ocfb_init_var(struct ocfb_dev *fbdev) |
231 | { |
232 | struct fb_var_screeninfo *var = &fbdev->info.var; |
233 | |
234 | var->accel_flags = FB_ACCEL_NONE; |
235 | var->activate = FB_ACTIVATE_NOW; |
236 | var->xres_virtual = var->xres; |
237 | var->yres_virtual = var->yres; |
238 | |
239 | switch (var->bits_per_pixel) { |
240 | case 8: |
241 | var->transp.offset = 0; |
242 | var->transp.length = 0; |
243 | var->red.offset = 0; |
244 | var->red.length = 8; |
245 | var->green.offset = 0; |
246 | var->green.length = 8; |
247 | var->blue.offset = 0; |
248 | var->blue.length = 8; |
249 | break; |
250 | |
251 | case 16: |
252 | var->transp.offset = 0; |
253 | var->transp.length = 0; |
254 | var->red.offset = 11; |
255 | var->red.length = 5; |
256 | var->green.offset = 5; |
257 | var->green.length = 6; |
258 | var->blue.offset = 0; |
259 | var->blue.length = 5; |
260 | break; |
261 | |
262 | case 24: |
263 | var->transp.offset = 0; |
264 | var->transp.length = 0; |
265 | var->red.offset = 16; |
266 | var->red.length = 8; |
267 | var->green.offset = 8; |
268 | var->green.length = 8; |
269 | var->blue.offset = 0; |
270 | var->blue.length = 8; |
271 | break; |
272 | |
273 | case 32: |
274 | var->transp.offset = 24; |
275 | var->transp.length = 8; |
276 | var->red.offset = 16; |
277 | var->red.length = 8; |
278 | var->green.offset = 8; |
279 | var->green.length = 8; |
280 | var->blue.offset = 0; |
281 | var->blue.length = 8; |
282 | break; |
283 | } |
284 | |
285 | return 0; |
286 | } |
287 | |
288 | static const struct fb_ops ocfb_ops = { |
289 | .owner = THIS_MODULE, |
290 | FB_DEFAULT_IOMEM_OPS, |
291 | .fb_setcolreg = ocfb_setcolreg, |
292 | }; |
293 | |
294 | static int ocfb_probe(struct platform_device *pdev) |
295 | { |
296 | int ret = 0; |
297 | struct ocfb_dev *fbdev; |
298 | int fbsize; |
299 | |
300 | fbdev = devm_kzalloc(dev: &pdev->dev, size: sizeof(*fbdev), GFP_KERNEL); |
301 | if (!fbdev) |
302 | return -ENOMEM; |
303 | |
304 | platform_set_drvdata(pdev, data: fbdev); |
305 | |
306 | fbdev->info.fbops = &ocfb_ops; |
307 | fbdev->info.device = &pdev->dev; |
308 | fbdev->info.par = fbdev; |
309 | |
310 | /* Video mode setup */ |
311 | if (!fb_find_mode(var: &fbdev->info.var, info: &fbdev->info, mode_option, |
312 | NULL, dbsize: 0, default_mode: &default_mode, default_bpp: 16)) { |
313 | dev_err(&pdev->dev, "No valid video modes found\n" ); |
314 | return -EINVAL; |
315 | } |
316 | ocfb_init_var(fbdev); |
317 | ocfb_init_fix(fbdev); |
318 | |
319 | fbdev->regs = devm_platform_ioremap_resource(pdev, index: 0); |
320 | if (IS_ERR(ptr: fbdev->regs)) |
321 | return PTR_ERR(ptr: fbdev->regs); |
322 | |
323 | /* Allocate framebuffer memory */ |
324 | fbsize = fbdev->info.fix.smem_len; |
325 | fbdev->fb_virt = dma_alloc_coherent(dev: &pdev->dev, PAGE_ALIGN(fbsize), |
326 | dma_handle: &fbdev->fb_phys, GFP_KERNEL); |
327 | if (!fbdev->fb_virt) { |
328 | dev_err(&pdev->dev, |
329 | "Frame buffer memory allocation failed\n" ); |
330 | return -ENOMEM; |
331 | } |
332 | fbdev->info.fix.smem_start = fbdev->fb_phys; |
333 | fbdev->info.screen_base = fbdev->fb_virt; |
334 | fbdev->info.pseudo_palette = fbdev->pseudo_palette; |
335 | |
336 | /* Clear framebuffer */ |
337 | memset_io(fbdev->fb_virt, 0, fbsize); |
338 | |
339 | /* Setup and enable the framebuffer */ |
340 | ocfb_setupfb(fbdev); |
341 | |
342 | if (fbdev->little_endian) |
343 | fbdev->info.flags |= FBINFO_FOREIGN_ENDIAN; |
344 | |
345 | /* Allocate color map */ |
346 | ret = fb_alloc_cmap(cmap: &fbdev->info.cmap, PALETTE_SIZE, transp: 0); |
347 | if (ret) { |
348 | dev_err(&pdev->dev, "Color map allocation failed\n" ); |
349 | goto err_dma_free; |
350 | } |
351 | |
352 | /* Register framebuffer */ |
353 | ret = register_framebuffer(fb_info: &fbdev->info); |
354 | if (ret) { |
355 | dev_err(&pdev->dev, "Framebuffer registration failed\n" ); |
356 | goto err_dealloc_cmap; |
357 | } |
358 | |
359 | return 0; |
360 | |
361 | err_dealloc_cmap: |
362 | fb_dealloc_cmap(cmap: &fbdev->info.cmap); |
363 | |
364 | err_dma_free: |
365 | dma_free_coherent(dev: &pdev->dev, PAGE_ALIGN(fbsize), cpu_addr: fbdev->fb_virt, |
366 | dma_handle: fbdev->fb_phys); |
367 | |
368 | return ret; |
369 | } |
370 | |
371 | static void ocfb_remove(struct platform_device *pdev) |
372 | { |
373 | struct ocfb_dev *fbdev = platform_get_drvdata(pdev); |
374 | |
375 | unregister_framebuffer(fb_info: &fbdev->info); |
376 | fb_dealloc_cmap(cmap: &fbdev->info.cmap); |
377 | dma_free_coherent(dev: &pdev->dev, PAGE_ALIGN(fbdev->info.fix.smem_len), |
378 | cpu_addr: fbdev->fb_virt, dma_handle: fbdev->fb_phys); |
379 | |
380 | /* Disable display */ |
381 | ocfb_writereg(fbdev, OCFB_CTRL, data: 0); |
382 | |
383 | platform_set_drvdata(pdev, NULL); |
384 | } |
385 | |
386 | static const struct of_device_id ocfb_match[] = { |
387 | { .compatible = "opencores,ocfb" , }, |
388 | {}, |
389 | }; |
390 | MODULE_DEVICE_TABLE(of, ocfb_match); |
391 | |
392 | static struct platform_driver ocfb_driver = { |
393 | .probe = ocfb_probe, |
394 | .remove_new = ocfb_remove, |
395 | .driver = { |
396 | .name = "ocfb_fb" , |
397 | .of_match_table = ocfb_match, |
398 | } |
399 | }; |
400 | |
401 | /* |
402 | * Init and exit routines |
403 | */ |
404 | static int __init ocfb_init(void) |
405 | { |
406 | #ifndef MODULE |
407 | char *option = NULL; |
408 | |
409 | if (fb_get_options(name: "ocfb" , option: &option)) |
410 | return -ENODEV; |
411 | ocfb_setup(options: option); |
412 | #endif |
413 | return platform_driver_register(&ocfb_driver); |
414 | } |
415 | |
416 | static void __exit ocfb_exit(void) |
417 | { |
418 | platform_driver_unregister(&ocfb_driver); |
419 | } |
420 | |
421 | module_init(ocfb_init); |
422 | module_exit(ocfb_exit); |
423 | |
424 | MODULE_AUTHOR("Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>" ); |
425 | MODULE_DESCRIPTION("OpenCores VGA/LCD 2.0 frame buffer driver" ); |
426 | MODULE_LICENSE("GPL v2" ); |
427 | module_param(mode_option, charp, 0); |
428 | MODULE_PARM_DESC(mode_option, "Video mode ('<xres>x<yres>[-<bpp>][@refresh]')" ); |
429 | |