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1/*2 * OpenCores VGA/LCD 2.0 core frame buffer driver3 *4 * Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson@saunalahti.fi5 *6 * This file is licensed under the terms of the GNU General Public License7 * version 2. This program is licensed "as is" without any warranty of any8 * 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 0x00027#define OCFB_STAT 0x00428#define OCFB_HTIM 0x00829#define OCFB_VTIM 0x00c30#define OCFB_HVLEN 0x01031#define OCFB_VBARA 0x01432#define OCFB_PALETTE 0x80033 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 25647 48#define OCFB_NAME "OC VGA/LCD"49 50static char *mode_option;51 52static 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_NONINTERLACED56};57 58struct 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 MODULE70static 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#endif86 87static inline u32 ocfb_readreg(struct ocfb_dev *fbdev, loff_t offset)88{89 if (fbdev->little_endian)90 return ioread32(fbdev->regs + offset);91 else92 return ioread32be(fbdev->regs + offset);93}94 95static 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 else100 iowrite32be(data, fbdev->regs + offset);101}102 103static 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, 0);113 114 /* Register framebuffer address */115 fbdev->little_endian = 0;116 ocfb_writereg(fbdev, OCFB_VBARA, 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, fbdev->fb_phys);122 }123 124 /* Horizontal timings */125 ocfb_writereg(fbdev, OCFB_HTIM, (var->hsync_len - 1) << 24 |126 (var->left_margin - 1) << 16 | (var->xres - 1));127 128 /* Vertical timings */129 ocfb_writereg(fbdev, OCFB_VTIM, (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, (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, (OCFB_CTRL_VEN | bpp_config));170 171 return 0;172}173 174static 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, 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 211static 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(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 else225 fix->visual = FB_VISUAL_TRUECOLOR;226 227 return 0;228}229 230static 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 288static const struct fb_ops ocfb_ops = {289 .owner = THIS_MODULE,290 FB_DEFAULT_IOMEM_OPS,291 .fb_setcolreg = ocfb_setcolreg,292};293 294static 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(&pdev->dev, sizeof(*fbdev), GFP_KERNEL);301 if (!fbdev)302 return -ENOMEM;303 304 platform_set_drvdata(pdev, 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(&fbdev->info.var, &fbdev->info, mode_option,312 NULL, 0, &default_mode, 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, 0);320 if (IS_ERR(fbdev->regs))321 return PTR_ERR(fbdev->regs);322 323 /* Allocate framebuffer memory */324 fbsize = fbdev->info.fix.smem_len;325 fbdev->fb_virt = dma_alloc_coherent(&pdev->dev, PAGE_ALIGN(fbsize),326 &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(&fbdev->info.cmap, PALETTE_SIZE, 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(&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 361err_dealloc_cmap:362 fb_dealloc_cmap(&fbdev->info.cmap);363 364err_dma_free:365 dma_free_coherent(&pdev->dev, PAGE_ALIGN(fbsize), fbdev->fb_virt,366 fbdev->fb_phys);367 368 return ret;369}370 371static void ocfb_remove(struct platform_device *pdev)372{373 struct ocfb_dev *fbdev = platform_get_drvdata(pdev);374 375 unregister_framebuffer(&fbdev->info);376 fb_dealloc_cmap(&fbdev->info.cmap);377 dma_free_coherent(&pdev->dev, PAGE_ALIGN(fbdev->info.fix.smem_len),378 fbdev->fb_virt, fbdev->fb_phys);379 380 /* Disable display */381 ocfb_writereg(fbdev, OCFB_CTRL, 0);382 383 platform_set_drvdata(pdev, NULL);384}385 386static const struct of_device_id ocfb_match[] = {387 { .compatible = "opencores,ocfb", },388 {},389};390MODULE_DEVICE_TABLE(of, ocfb_match);391 392static struct platform_driver ocfb_driver = {393 .probe = ocfb_probe,394 .remove = ocfb_remove,395 .driver = {396 .name = "ocfb_fb",397 .of_match_table = ocfb_match,398 }399};400 401/*402 * Init and exit routines403 */404static int __init ocfb_init(void)405{406#ifndef MODULE407 char *option = NULL;408 409 if (fb_get_options("ocfb", &option))410 return -ENODEV;411 ocfb_setup(option);412#endif413 return platform_driver_register(&ocfb_driver);414}415 416static void __exit ocfb_exit(void)417{418 platform_driver_unregister(&ocfb_driver);419}420 421module_init(ocfb_init);422module_exit(ocfb_exit);423 424MODULE_AUTHOR("Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>");425MODULE_DESCRIPTION("OpenCores VGA/LCD 2.0 frame buffer driver");426MODULE_LICENSE("GPL v2");427module_param(mode_option, charp, 0);428MODULE_PARM_DESC(mode_option, "Video mode ('<xres>x<yres>[-<bpp>][@refresh]')");429