diff mbox

[v3] video: add OpenCores VGA/LCD framebuffer driver

Message ID 1385094870-6962-1-git-send-email-stefan.kristiansson@saunalahti.fi (mailing list archive)
State New, archived
Headers show

Commit Message

Stefan Kristiansson Nov. 22, 2013, 4:34 a.m. UTC
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>
---
Changes in v2:
- Add Microblaze as an example user and fix a typo in Xilinx Zynq

Changes in v3:
- Use devm_kzalloc instead of kzalloc
- Remove superflous MODULE #ifdef
---
 drivers/video/Kconfig  |  17 ++
 drivers/video/Makefile |   1 +
 drivers/video/ocfb.c   | 471 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 489 insertions(+)
 create mode 100644 drivers/video/ocfb.c

Comments

Jean-Christophe PLAGNIOL-VILLARD Nov. 24, 2013, 2:12 p.m. UTC | #1
On 06:34 Fri 22 Nov     , Stefan Kristiansson wrote:
> 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>

Tomi hold on this one I need check fee stuff on it
> ---
> Changes in v2:
> - Add Microblaze as an example user and fix a typo in Xilinx Zynq
> 
> Changes in v3:
> - Use devm_kzalloc instead of kzalloc
> - Remove superflous MODULE #ifdef
> ---
>  drivers/video/Kconfig  |  17 ++
>  drivers/video/Makefile |   1 +
>  drivers/video/ocfb.c   | 471 +++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 489 insertions(+)
>  create mode 100644 drivers/video/ocfb.c
> 
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> index 84b685f..3b3f31e 100644
> --- a/drivers/video/Kconfig
> +++ b/drivers/video/Kconfig
> @@ -979,6 +979,23 @@ 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
> +	default n
non need

Best Regards,
J.
> +	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
> diff --git a/drivers/video/Makefile b/drivers/video/Makefile
> index e8bae8d..ae17ddf 100644
> --- a/drivers/video/Makefile
> +++ b/drivers/video/Makefile
> @@ -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
> index 0000000..3bf5f67
> --- /dev/null
> +++ b/drivers/video/ocfb.c
> @@ -0,0 +1,471 @@
> +/*
> + * 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/module.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/string.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include <linux/mm.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/fb.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.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;
> +	/* Physical and virtual addresses of control regs */
> +	phys_addr_t regs_phys;
> +	int regs_phys_size;
> +	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];
> +};
> +
> +struct ocfb_par {
> +	void __iomem *pal_adr;
> +};
> +
> +static struct ocfb_par ocfb_par_priv;
> +
> +static struct fb_var_screeninfo ocfb_var;
> +static struct fb_fix_screeninfo ocfb_fix;
> +
> +#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_par *par = (struct ocfb_par *)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(par->pal_adr, 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 ocfb_par *par = &ocfb_par_priv;
> +	struct resource *res;
> +	struct resource *mmio;
> +	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.var = ocfb_var;
> +	fbdev->info.fix = ocfb_fix;
> +	fbdev->info.device = &pdev->dev;
> +	fbdev->info.par = par;
> +
> +	/* 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_phys = res->start;
> +	fbdev->regs_phys_size = resource_size(res);
> +	mmio = devm_request_mem_region(&pdev->dev, res->start,
> +				       resource_size(res), res->name);
> +	if (!mmio) {
> +		dev_err(&pdev->dev, "I/O memory space request failed\n");
> +		return -ENXIO;
> +	}
> +	fbdev->regs = devm_ioremap_nocache(&pdev->dev, mmio->start,
> +					   resource_size(mmio));
> +	if (!fbdev->regs) {
> +		dev_err(&pdev->dev, "I/O memory remap request failed\n");
> +		return -ENXIO;
> +	}
> +	par->pal_adr = fbdev->regs + OCFB_PALETTE;
> +
> +	/* 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");
> +		ret = -ENOMEM;
> +		goto err_release;
> +	}
> +	fbdev->info.fix.smem_start = fbdev->fb_phys;
> +	fbdev->info.screen_base = (void __iomem *)fbdev->fb_virt;
> +	fbdev->info.pseudo_palette = fbdev->pseudo_palette;
> +
> +	/* Clear framebuffer */
> +	memset_io((void __iomem *)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);
> +err_release:
> +	release_mem_region(fbdev->regs_phys, fbdev->regs_phys_size);
> +
> +	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);
> +
> +	release_mem_region(fbdev->regs_phys, fbdev->regs_phys_size);
> +	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]')");
> -- 
> 1.8.3.2
> 
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Stefan Kristiansson Nov. 26, 2013, 6:55 a.m. UTC | #2
On Sun, Nov 24, 2013 at 03:12:11PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 06:34 Fri 22 Nov     , Stefan Kristiansson wrote:
> > 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>
> 
> Tomi hold on this one I need check fee stuff on it
> > ---
> > Changes in v2:
> > - Add Microblaze as an example user and fix a typo in Xilinx Zynq
> > 
> > Changes in v3:
> > - Use devm_kzalloc instead of kzalloc
> > - Remove superflous MODULE #ifdef
> > ---
> >  drivers/video/Kconfig  |  17 ++
> >  drivers/video/Makefile |   1 +
> >  drivers/video/ocfb.c   | 471 +++++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 489 insertions(+)
> >  create mode 100644 drivers/video/ocfb.c
> > 
> > diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> > index 84b685f..3b3f31e 100644
> > --- a/drivers/video/Kconfig
> > +++ b/drivers/video/Kconfig
> > @@ -979,6 +979,23 @@ 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
> > +	default n
> non need
> 

Ok, let's get rid of that then.

I'll hold on to v4 for a while, since it sounded you potentially had some
additional comments coming up?

Stefan
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Michal Simek Nov. 26, 2013, 7:10 a.m. UTC | #3
On 11/22/2013 05:34 AM, Stefan Kristiansson wrote:
> 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>
> ---
> Changes in v2:
> - Add Microblaze as an example user and fix a typo in Xilinx Zynq
> 
> Changes in v3:
> - Use devm_kzalloc instead of kzalloc
> - Remove superflous MODULE #ifdef
> ---
>  drivers/video/Kconfig  |  17 ++
>  drivers/video/Makefile |   1 +
>  drivers/video/ocfb.c   | 471 +++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 489 insertions(+)
>  create mode 100644 drivers/video/ocfb.c
> 
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> index 84b685f..3b3f31e 100644
> --- a/drivers/video/Kconfig
> +++ b/drivers/video/Kconfig
> @@ -979,6 +979,23 @@ 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
> +	default n
> +	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
> diff --git a/drivers/video/Makefile b/drivers/video/Makefile
> index e8bae8d..ae17ddf 100644
> --- a/drivers/video/Makefile
> +++ b/drivers/video/Makefile
> @@ -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
> index 0000000..3bf5f67
> --- /dev/null
> +++ b/drivers/video/ocfb.c
> @@ -0,0 +1,471 @@
> +/*
> + * 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/module.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/string.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +#include <linux/mm.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/fb.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.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;
> +	/* Physical and virtual addresses of control regs */
> +	phys_addr_t regs_phys;
> +	int regs_phys_size;
> +	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];
> +};
> +
> +struct ocfb_par {
> +	void __iomem *pal_adr;
> +};
> +
> +static struct ocfb_par ocfb_par_priv;
> +
> +static struct fb_var_screeninfo ocfb_var;
> +static struct fb_fix_screeninfo ocfb_fix;
> +
> +#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_par *par = (struct ocfb_par *)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(par->pal_adr, 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 ocfb_par *par = &ocfb_par_priv;
> +	struct resource *res;
> +	struct resource *mmio;
> +	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.var = ocfb_var;
> +	fbdev->info.fix = ocfb_fix;
> +	fbdev->info.device = &pdev->dev;
> +	fbdev->info.par = par;
> +
> +	/* 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_phys = res->start;
> +	fbdev->regs_phys_size = resource_size(res);
> +	mmio = devm_request_mem_region(&pdev->dev, res->start,
> +				       resource_size(res), res->name);
> +	if (!mmio) {
> +		dev_err(&pdev->dev, "I/O memory space request failed\n");
> +		return -ENXIO;
> +	}
> +	fbdev->regs = devm_ioremap_nocache(&pdev->dev, mmio->start,
> +					   resource_size(mmio));
> +	if (!fbdev->regs) {
> +		dev_err(&pdev->dev, "I/O memory remap request failed\n");
> +		return -ENXIO;
> +	}


This construction seems to me too complicated and can be simpler.

What about this?
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	res->flags &= ~IORESOURCE_CACHEABLE;
	fbdev->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(fbdev->regs))
		return PTR_ERR(fbdev->regs);

Thanks,
Michal
Stefan Kristiansson Nov. 26, 2013, 8:13 a.m. UTC | #4
On Tue, Nov 26, 2013 at 08:10:46AM +0100, Michal Simek wrote:
> On 11/22/2013 05:34 AM, Stefan Kristiansson wrote:
> > +
> > +	/* 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_phys = res->start;
> > +	fbdev->regs_phys_size = resource_size(res);
> > +	mmio = devm_request_mem_region(&pdev->dev, res->start,
> > +				       resource_size(res), res->name);
> > +	if (!mmio) {
> > +		dev_err(&pdev->dev, "I/O memory space request failed\n");
> > +		return -ENXIO;
> > +	}
> > +	fbdev->regs = devm_ioremap_nocache(&pdev->dev, mmio->start,
> > +					   resource_size(mmio));
> > +	if (!fbdev->regs) {
> > +		dev_err(&pdev->dev, "I/O memory remap request failed\n");
> > +		return -ENXIO;
> > +	}
> 
> 
> This construction seems to me too complicated and can be simpler.
> 
> What about this?
> 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> 	res->flags &= ~IORESOURCE_CACHEABLE;
> 	fbdev->regs = devm_ioremap_resource(&pdev->dev, res);
> 	if (IS_ERR(fbdev->regs))
> 		return PTR_ERR(fbdev->regs);
> 

Yes, that looks better.

Slightly related, I also noticed that I have a release_mem_region even though I
used devm_request_mem_region to request it.
I will fix that as well.

Stefan
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Geert Uytterhoeven Nov. 26, 2013, 8:19 a.m. UTC | #5
On Tue, Nov 26, 2013 at 8:10 AM, Michal Simek <monstr@monstr.eu> wrote:
> On 11/22/2013 05:34 AM, Stefan Kristiansson wrote:
> This construction seems to me too complicated and can be simpler.
>
> What about this?
>         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

Don't forget to check for res being non-NULL here.

>         res->flags &= ~IORESOURCE_CACHEABLE;
>         fbdev->regs = devm_ioremap_resource(&pdev->dev, res);
>         if (IS_ERR(fbdev->regs))
>                 return PTR_ERR(fbdev->regs);

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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Michal Simek Nov. 26, 2013, 8:22 a.m. UTC | #6
On 11/26/2013 09:19 AM, Geert Uytterhoeven wrote:
> On Tue, Nov 26, 2013 at 8:10 AM, Michal Simek <monstr@monstr.eu> wrote:
>> On 11/22/2013 05:34 AM, Stefan Kristiansson wrote:
>> This construction seems to me too complicated and can be simpler.
>>
>> What about this?
>>         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> 
> Don't forget to check for res being non-NULL here.

yes. you are right - you have to do it.

Thanks,
Michal
diff mbox

Patch

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 84b685f..3b3f31e 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -979,6 +979,23 @@  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
+	default n
+	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
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index e8bae8d..ae17ddf 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -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
index 0000000..3bf5f67
--- /dev/null
+++ b/drivers/video/ocfb.c
@@ -0,0 +1,471 @@ 
+/*
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/of.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;
+	/* Physical and virtual addresses of control regs */
+	phys_addr_t regs_phys;
+	int regs_phys_size;
+	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];
+};
+
+struct ocfb_par {
+	void __iomem *pal_adr;
+};
+
+static struct ocfb_par ocfb_par_priv;
+
+static struct fb_var_screeninfo ocfb_var;
+static struct fb_fix_screeninfo ocfb_fix;
+
+#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_par *par = (struct ocfb_par *)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(par->pal_adr, 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 ocfb_par *par = &ocfb_par_priv;
+	struct resource *res;
+	struct resource *mmio;
+	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.var = ocfb_var;
+	fbdev->info.fix = ocfb_fix;
+	fbdev->info.device = &pdev->dev;
+	fbdev->info.par = par;
+
+	/* 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_phys = res->start;
+	fbdev->regs_phys_size = resource_size(res);
+	mmio = devm_request_mem_region(&pdev->dev, res->start,
+				       resource_size(res), res->name);
+	if (!mmio) {
+		dev_err(&pdev->dev, "I/O memory space request failed\n");
+		return -ENXIO;
+	}
+	fbdev->regs = devm_ioremap_nocache(&pdev->dev, mmio->start,
+					   resource_size(mmio));
+	if (!fbdev->regs) {
+		dev_err(&pdev->dev, "I/O memory remap request failed\n");
+		return -ENXIO;
+	}
+	par->pal_adr = fbdev->regs + OCFB_PALETTE;
+
+	/* 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");
+		ret = -ENOMEM;
+		goto err_release;
+	}
+	fbdev->info.fix.smem_start = fbdev->fb_phys;
+	fbdev->info.screen_base = (void __iomem *)fbdev->fb_virt;
+	fbdev->info.pseudo_palette = fbdev->pseudo_palette;
+
+	/* Clear framebuffer */
+	memset_io((void __iomem *)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);
+err_release:
+	release_mem_region(fbdev->regs_phys, fbdev->regs_phys_size);
+
+	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);
+
+	release_mem_region(fbdev->regs_phys, fbdev->regs_phys_size);
+	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]')");