/* * 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 MODULEstatic 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_DEFAULT_IOMEM_OPS,	.fb_setcolreg	= ocfb_setcolreg,}; 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 void 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);} static const 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]')");