- 根目录:
- drivers
- video
- fbdev
- ocfb.c
/*
* 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->right_margin - 1) << 16 | (var->xres - 1));
/* Vertical timings */
ocfb_writereg(fbdev, OCFB_VTIM, (var->vsync_len - 1) << 24 |
(var->lower_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;
}
res->flags &= ~IORESOURCE_CACHEABLE;
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]')");