/* * OpenCores VGA/LCD 2.0 core frame buffer driver * * Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson@saunalahti.fi * * This file is licensed under the terms of the GNU General Public License * version 2. This program is licensed "as is" without any warranty of any * kind, whether express or implied. */ #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/errno.h> #include <linux/fb.h> #include <linux/init.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/string.h> #include <linux/slab.h> /* OCFB register defines */ #define OCFB_CTRL 0x000 #define OCFB_STAT 0x004 #define OCFB_HTIM 0x008 #define OCFB_VTIM 0x00c #define OCFB_HVLEN 0x010 #define OCFB_VBARA 0x014 #define OCFB_PALETTE 0x800 #define OCFB_CTRL_VEN 0x00000001 /* Video Enable */ #define OCFB_CTRL_HIE 0x00000002 /* HSync Interrupt Enable */ #define OCFB_CTRL_PC 0x00000800 /* 8-bit Pseudo Color Enable*/ #define OCFB_CTRL_CD8 0x00000000 /* Color Depth 8 */ #define OCFB_CTRL_CD16 0x00000200 /* Color Depth 16 */ #define OCFB_CTRL_CD24 0x00000400 /* Color Depth 24 */ #define OCFB_CTRL_CD32 0x00000600 /* Color Depth 32 */ #define OCFB_CTRL_VBL1 0x00000000 /* Burst Length 1 */ #define OCFB_CTRL_VBL2 0x00000080 /* Burst Length 2 */ #define OCFB_CTRL_VBL4 0x00000100 /* Burst Length 4 */ #define OCFB_CTRL_VBL8 0x00000180 /* Burst Length 8 */ #define PALETTE_SIZE 256 #define OCFB_NAME "OC VGA/LCD" static char *mode_option; static const struct fb_videomode default_mode = { /* 640x480 @ 60 Hz, 31.5 kHz hsync */ NULL, 60, 640, 480, 39721, 40, 24, 32, 11, 96, 2, 0, FB_VMODE_NONINTERLACED }; struct ocfb_dev { struct fb_info info; void __iomem *regs; /* flag indicating whether the regs are little endian accessed */ int little_endian; /* Physical and virtual addresses of framebuffer */ dma_addr_t fb_phys; void __iomem *fb_virt; u32 pseudo_palette[PALETTE_SIZE]; }; #ifndef MODULE static int __init ocfb_setup(char *options) { char *curr_opt; if (!options || !*options) return 0; while ((curr_opt = strsep(&options, ",")) != NULL) { if (!*curr_opt) continue; mode_option = curr_opt; } return 0; } #endif static inline u32 ocfb_readreg(struct ocfb_dev *fbdev, loff_t offset) { if (fbdev->little_endian) return ioread32(fbdev->regs + offset); else return ioread32be(fbdev->regs + offset); } static void ocfb_writereg(struct ocfb_dev *fbdev, loff_t offset, u32 data) { if (fbdev->little_endian) iowrite32(data, fbdev->regs + offset); else iowrite32be(data, fbdev->regs + offset); } static int ocfb_setupfb(struct ocfb_dev *fbdev) { unsigned long bpp_config; struct fb_var_screeninfo *var = &fbdev->info.var; struct device *dev = fbdev->info.device; u32 hlen; u32 vlen; /* Disable display */ ocfb_writereg(fbdev, OCFB_CTRL, 0); /* Register framebuffer address */ fbdev->little_endian = 0; ocfb_writereg(fbdev, OCFB_VBARA, fbdev->fb_phys); /* Detect endianess */ if (ocfb_readreg(fbdev, OCFB_VBARA) != fbdev->fb_phys) { fbdev->little_endian = 1; ocfb_writereg(fbdev, OCFB_VBARA, fbdev->fb_phys); } /* Horizontal timings */ ocfb_writereg(fbdev, OCFB_HTIM, (var->hsync_len - 1) << 24 | (var->left_margin - 1) << 16 | (var->xres - 1)); /* Vertical timings */ ocfb_writereg(fbdev, OCFB_VTIM, (var->vsync_len - 1) << 24 | (var->upper_margin - 1) << 16 | (var->yres - 1)); /* Total length of frame */ hlen = var->left_margin + var->right_margin + var->hsync_len + var->xres; vlen = var->upper_margin + var->lower_margin + var->vsync_len + var->yres; ocfb_writereg(fbdev, OCFB_HVLEN, (hlen - 1) << 16 | (vlen - 1)); bpp_config = OCFB_CTRL_CD8; switch (var->bits_per_pixel) { case 8: if (!var->grayscale) bpp_config |= OCFB_CTRL_PC; /* enable palette */ break; case 16: bpp_config |= OCFB_CTRL_CD16; break; case 24: bpp_config |= OCFB_CTRL_CD24; break; case 32: bpp_config |= OCFB_CTRL_CD32; break; default: dev_err(dev, "no bpp specified\n"); break; } /* maximum (8) VBL (video memory burst length) */ bpp_config |= OCFB_CTRL_VBL8; /* Enable output */ ocfb_writereg(fbdev, OCFB_CTRL, (OCFB_CTRL_VEN | bpp_config)); return 0; } static int ocfb_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info) { struct ocfb_dev *fbdev = (struct ocfb_dev *)info->par; u32 color; if (regno >= info->cmap.len) { dev_err(info->device, "regno >= cmap.len\n"); return 1; } if (info->var.grayscale) { /* grayscale = 0.30*R + 0.59*G + 0.11*B */ red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8; } red >>= (16 - info->var.red.length); green >>= (16 - info->var.green.length); blue >>= (16 - info->var.blue.length); transp >>= (16 - info->var.transp.length); if (info->var.bits_per_pixel == 8 && !info->var.grayscale) { regno <<= 2; color = (red << 16) | (green << 8) | blue; ocfb_writereg(fbdev, OCFB_PALETTE + regno, color); } else { ((u32 *)(info->pseudo_palette))[regno] = (red << info->var.red.offset) | (green << info->var.green.offset) | (blue << info->var.blue.offset) | (transp << info->var.transp.offset); } return 0; } static int ocfb_init_fix(struct ocfb_dev *fbdev) { struct fb_var_screeninfo *var = &fbdev->info.var; struct fb_fix_screeninfo *fix = &fbdev->info.fix; strcpy(fix->id, OCFB_NAME); fix->line_length = var->xres * var->bits_per_pixel/8; fix->smem_len = fix->line_length * var->yres; fix->type = FB_TYPE_PACKED_PIXELS; if (var->bits_per_pixel == 8 && !var->grayscale) fix->visual = FB_VISUAL_PSEUDOCOLOR; else fix->visual = FB_VISUAL_TRUECOLOR; return 0; } static int ocfb_init_var(struct ocfb_dev *fbdev) { struct fb_var_screeninfo *var = &fbdev->info.var; var->accel_flags = FB_ACCEL_NONE; var->activate = FB_ACTIVATE_NOW; var->xres_virtual = var->xres; var->yres_virtual = var->yres; switch (var->bits_per_pixel) { case 8: var->transp.offset = 0; var->transp.length = 0; var->red.offset = 0; var->red.length = 8; var->green.offset = 0; var->green.length = 8; var->blue.offset = 0; var->blue.length = 8; break; case 16: var->transp.offset = 0; var->transp.length = 0; var->red.offset = 11; var->red.length = 5; var->green.offset = 5; var->green.length = 6; var->blue.offset = 0; var->blue.length = 5; break; case 24: var->transp.offset = 0; var->transp.length = 0; var->red.offset = 16; var->red.length = 8; var->green.offset = 8; var->green.length = 8; var->blue.offset = 0; var->blue.length = 8; break; case 32: var->transp.offset = 24; var->transp.length = 8; var->red.offset = 16; var->red.length = 8; var->green.offset = 8; var->green.length = 8; var->blue.offset = 0; var->blue.length = 8; break; } return 0; } static const struct fb_ops ocfb_ops = { .owner = THIS_MODULE, .fb_setcolreg = ocfb_setcolreg, .fb_fillrect = cfb_fillrect, .fb_copyarea = cfb_copyarea, .fb_imageblit = cfb_imageblit, }; static int ocfb_probe(struct platform_device *pdev) { int ret = 0; struct ocfb_dev *fbdev; int fbsize; fbdev = devm_kzalloc(&pdev->dev, sizeof(*fbdev), GFP_KERNEL); if (!fbdev) return -ENOMEM; platform_set_drvdata(pdev, fbdev); fbdev->info.fbops = &ocfb_ops; fbdev->info.device = &pdev->dev; fbdev->info.par = fbdev; /* Video mode setup */ if (!fb_find_mode(&fbdev->info.var, &fbdev->info, mode_option, NULL, 0, &default_mode, 16)) { dev_err(&pdev->dev, "No valid video modes found\n"); return -EINVAL; } ocfb_init_var(fbdev); ocfb_init_fix(fbdev); fbdev->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(fbdev->regs)) return PTR_ERR(fbdev->regs); /* Allocate framebuffer memory */ fbsize = fbdev->info.fix.smem_len; fbdev->fb_virt = dma_alloc_coherent(&pdev->dev, PAGE_ALIGN(fbsize), &fbdev->fb_phys, GFP_KERNEL); if (!fbdev->fb_virt) { dev_err(&pdev->dev, "Frame buffer memory allocation failed\n"); return -ENOMEM; } fbdev->info.fix.smem_start = fbdev->fb_phys; fbdev->info.screen_base = fbdev->fb_virt; fbdev->info.pseudo_palette = fbdev->pseudo_palette; /* Clear framebuffer */ memset_io(fbdev->fb_virt, 0, fbsize); /* Setup and enable the framebuffer */ ocfb_setupfb(fbdev); if (fbdev->little_endian) fbdev->info.flags |= FBINFO_FOREIGN_ENDIAN; /* Allocate color map */ ret = fb_alloc_cmap(&fbdev->info.cmap, PALETTE_SIZE, 0); if (ret) { dev_err(&pdev->dev, "Color map allocation failed\n"); goto err_dma_free; } /* Register framebuffer */ ret = register_framebuffer(&fbdev->info); if (ret) { dev_err(&pdev->dev, "Framebuffer registration failed\n"); goto err_dealloc_cmap; } return 0; err_dealloc_cmap: fb_dealloc_cmap(&fbdev->info.cmap); err_dma_free: dma_free_coherent(&pdev->dev, PAGE_ALIGN(fbsize), fbdev->fb_virt, fbdev->fb_phys); return ret; } static int ocfb_remove(struct platform_device *pdev) { struct ocfb_dev *fbdev = platform_get_drvdata(pdev); unregister_framebuffer(&fbdev->info); fb_dealloc_cmap(&fbdev->info.cmap); dma_free_coherent(&pdev->dev, PAGE_ALIGN(fbdev->info.fix.smem_len), fbdev->fb_virt, fbdev->fb_phys); /* Disable display */ ocfb_writereg(fbdev, OCFB_CTRL, 0); platform_set_drvdata(pdev, NULL); return 0; } static struct of_device_id ocfb_match[] = { { .compatible = "opencores,ocfb", }, {}, }; MODULE_DEVICE_TABLE(of, ocfb_match); static struct platform_driver ocfb_driver = { .probe = ocfb_probe, .remove = ocfb_remove, .driver = { .name = "ocfb_fb", .of_match_table = ocfb_match, } }; /* * Init and exit routines */ static int __init ocfb_init(void) { #ifndef MODULE char *option = NULL; if (fb_get_options("ocfb", &option)) return -ENODEV; ocfb_setup(option); #endif return platform_driver_register(&ocfb_driver); } static void __exit ocfb_exit(void) { platform_driver_unregister(&ocfb_driver); } module_init(ocfb_init); module_exit(ocfb_exit); MODULE_AUTHOR("Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>"); MODULE_DESCRIPTION("OpenCores VGA/LCD 2.0 frame buffer driver"); MODULE_LICENSE("GPL v2"); module_param(mode_option, charp, 0); MODULE_PARM_DESC(mode_option, "Video mode ('<xres>x<yres>[-<bpp>][@refresh]')");