diff options
Diffstat (limited to 'drivers/video/fbdev/ocfb.c')
| -rw-r--r-- | drivers/video/fbdev/ocfb.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/drivers/video/fbdev/ocfb.c b/drivers/video/fbdev/ocfb.c new file mode 100644 index 000000000..a970edc2a --- /dev/null +++ b/drivers/video/fbdev/ocfb.c @@ -0,0 +1,439 @@ +/* + * 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 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; + struct resource *res; + 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); + + /* Request I/O resource */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "I/O resource request failed\n"); + return -ENXIO; + } + fbdev->regs = devm_ioremap_resource(&pdev->dev, res); + 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]')"); |