video: add OpenCores VGA/LCD framebuffer driver
authorStefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Mon, 13 Jan 2014 19:38:10 +0000 (21:38 +0200)
committerTomi Valkeinen <tomi.valkeinen@ti.com>
Fri, 17 Jan 2014 08:57:49 +0000 (10:57 +0200)
This adds support for the VGA/LCD core available from OpenCores:
http://opencores.org/project,vga_lcd

The driver have been tested together with both OpenRISC and
ARM (socfpga) processors.

Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
drivers/video/Kconfig
drivers/video/Makefile
drivers/video/ocfb.c [new file with mode: 0644]

index e6c7fb1..22262a3 100644 (file)
@@ -980,6 +980,22 @@ config FB_PVR2
          (<file:drivers/video/pvr2fb.c>). Please see the file
          <file:Documentation/fb/pvr2fb.txt>.
 
+config FB_OPENCORES
+       tristate "OpenCores VGA/LCD core 2.0 framebuffer support"
+       depends on FB
+       select FB_CFB_FILLRECT
+       select FB_CFB_COPYAREA
+       select FB_CFB_IMAGEBLIT
+       help
+         This enables support for the OpenCores VGA/LCD core.
+
+         The OpenCores VGA/LCD core is typically used together with
+         softcore CPUs (e.g. OpenRISC or Microblaze) or hard processor
+         systems (e.g. Altera socfpga or Xilinx Zynq) on FPGAs.
+
+         The source code and specification for the core is available at
+         <http://opencores.org/project,vga_lcd>
+
 config FB_S1D13XXX
        tristate "Epson S1D13XXX framebuffer support"
        depends on FB
index e8bae8d..ae17ddf 100644 (file)
@@ -150,6 +150,7 @@ obj-$(CONFIG_FB_NUC900)           += nuc900fb.o
 obj-$(CONFIG_FB_JZ4740)                  += jz4740_fb.o
 obj-$(CONFIG_FB_PUV3_UNIGFX)      += fb-puv3.o
 obj-$(CONFIG_FB_HYPERV)                  += hyperv_fb.o
+obj-$(CONFIG_FB_OPENCORES)       += ocfb.o
 
 # Platform or fallback drivers go here
 obj-$(CONFIG_FB_UVESA)            += uvesafb.o
diff --git a/drivers/video/ocfb.c b/drivers/video/ocfb.c
new file mode 100644 (file)
index 0000000..7f9dc9b
--- /dev/null
@@ -0,0 +1,440 @@
+/*
+ * 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]')");