--- /dev/null
+/*
+ * 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 */
+ phys_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]')");
projects / linux-beck.git / commitdiff