Subject: [PATCH] Xilinx framebuffer device driver - 4th version

From: Andrei Konovalov <[email-masked]>
Date: Fri, 04 May 2007 19:25:00 +0400

Add support for the video controller IP block included into Xilinx ML300
and ML403 reference designs.

Signed-off-by: Andrei Konovalov <[email-masked]>

-----

The patch is against 2.6.21-git4 snapshot.

Fixed the issues pointed out by Antonino A. Daplas. Thanks Antonino!

Here is the interdiff against the previous version:

===8<===
diff -u linux-2.6.20/drivers/video/xilinxfb.c linux-2.6.20/drivers/video/xilinxfb.c
--- linux-2.6.20/drivers/video/xilinxfb.c
+++ linux-2.6.20/drivers/video/xilinxfb.c
@@ -167,14 +167,15 @@
  	struct xilinxfb_drvdata *drvdata = to_xilinxfb_drvdata(fbi);

  	switch (blank_mode) {
-	case VESA_NO_BLANKING:
+	case FB_BLANK_UNBLANK:
  		/* turn on panel */
  		xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);
  		break;

-	case VESA_VSYNC_SUSPEND:
-	case VESA_HSYNC_SUSPEND:
-	case VESA_POWERDOWN:
+	case FB_BLANK_NORMAL:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_POWERDOWN:
  		/* turn off panel */
  		xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
  	default:
@@ -184,21 +185,11 @@
  	return 0; /* success */
  }

-static int
-xilinx_fb_pan_display(struct fb_var_screeninfo *var, struct fb_info *fbi)
-{
-	if (var->xoffset != 0 || var->yoffset != 0)
-		return -EINVAL;
-
-	return 0;
-}
-
  static struct fb_ops xilinxfb_ops =
  {
  	.owner			= THIS_MODULE,
  	.fb_setcolreg		= xilinx_fb_setcolreg,
  	.fb_blank		= xilinx_fb_blank,
-	.fb_pan_display		= xilinx_fb_pan_display,
  	.fb_fillrect		= cfb_fillrect,
  	.fb_copyarea		= cfb_copyarea,
  	.fb_imageblit		= cfb_imageblit,
@@ -219,7 +210,7 @@
  		return -EINVAL;

  	pdev = to_platform_device(dev);
-	pdata = (struct xilinxfb_platform_data *)pdev->dev.platform_data;
+	pdata = pdev->dev.platform_data;

  	if (pdata == NULL) {
  		printk(KERN_ERR "Couldn't find platform data.\n");
@@ -231,7 +222,7 @@
  		printk(KERN_ERR "Couldn't allocate device private record\n");
  		return -ENOMEM;
  	}
-	dev_set_drvdata(dev, (void *)drvdata);
+	dev_set_drvdata(dev, drvdata);

  	/* Map the control registers in */
  	regs_res = platform_get_resource(pdev, IORESOURCE_IO, 0);
@@ -261,7 +252,7 @@
  	}

  	/* Clear (turn to black) the framebuffer */
-	memset((void *) drvdata->fb_virt, 0, FB_SIZE);
+	memset_io((void *) drvdata->fb_virt, 0, FB_SIZE);

  	/* Tell the hardware where the frame buffer is */
  	xilinx_fb_out_be32(drvdata, REG_FB_ADDR, drvdata->fb_phys);
@@ -275,6 +266,7 @@
  	xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);

  	/* Fill struct fb_info */
+	drvdata->info.device = dev;
  	drvdata->info.screen_base = drvdata->fb_virt;
  	drvdata->info.fbops = &xilinxfb_ops;
  	drvdata->info.fix = xilinx_fb_fix;
===8<===

And here is the patch itself:
===8<===
Add support for the video controller IP block included into Xilinx ML300 and
ML403 reference designs.

  arch/ppc/syslib/virtex_devices.h |    7
  drivers/video/Kconfig            |   11 +
  drivers/video/Makefile           |    1
  drivers/video/xilinxfb.c         |  381 +++++++++++++++++++++++++++++++++++++++
  4 files changed, 400 insertions(+)

Index: linux-2.6.20/drivers/video/Kconfig
===================================================================
--- linux-2.6.20.orig/drivers/video/Kconfig
+++ linux-2.6.20/drivers/video/Kconfig
@@ -1633,6 +1633,17 @@ config FB_PS3_DEFAULT_SIZE_M
  	  The default value can be overridden on the kernel command line
  	  using the "ps3fb" option (e.g. "ps3fb=9M");

+config FB_XILINX
+	tristate "Xilinx frame buffer support"
+	depends on FB && XILINX_VIRTEX
+	select FB_CFB_FILLRECT
+	select FB_CFB_COPYAREA
+	select FB_CFB_IMAGEBLIT
+	---help---
+	  Include support for the Xilinx ML300/ML403 reference design
+	  framebuffer. ML300 carries a 640*480 LCD display on the board,
+	  ML403 uses a standard DB15 VGA connector.
+
  config FB_VIRTUAL
  	tristate "Virtual Frame Buffer support (ONLY FOR TESTING!)"
  	depends on FB
Index: linux-2.6.20/drivers/video/Makefile
===================================================================
--- linux-2.6.20.orig/drivers/video/Makefile
+++ linux-2.6.20/drivers/video/Makefile
@@ -99,6 +99,7 @@ obj-$(CONFIG_FB_PNX4008_DUM_RGB)  += pnx
  obj-$(CONFIG_FB_IBM_GXT4500)	  += gxt4500.o
  obj-$(CONFIG_FB_PS3)		  += ps3fb.o
  obj-$(CONFIG_FB_SM501)            += sm501fb.o
+obj-$(CONFIG_FB_XILINX)           += xilinxfb.o

  # Platform or fallback drivers go here
  obj-$(CONFIG_FB_VESA)             += vesafb.o
Index: linux-2.6.20/drivers/video/xilinxfb.c
===================================================================
--- /dev/null
+++ linux-2.6.20/drivers/video/xilinxfb.c
@@ -0,0 +1,381 @@
+/*
+ * xilinxfb.c
+ *
+ * Xilinx TFT LCD frame buffer driver
+ *
+ * Author: MontaVista Software, Inc.
+ *         [email-masked]
+ *
+ * 2002-2007 (c) MontaVista Software, Inc.  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.
+ */
+
+/*
+ * This driver was based on au1100fb.c by MontaVista rewritten for 2.6
+ * by Embedded Alley Solutions <[email-masked]>, which in turn
+ * was based on skeletonfb.c, Skeleton for a frame buffer device by
+ * Geert Uytterhoeven.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+
+#include <asm/io.h>
+#include <syslib/virtex_devices.h>
+
+#define DRIVER_NAME		"xilinxfb"
+#define DRIVER_DESCRIPTION	"Xilinx TFT LCD frame buffer driver"
+
+/*
+ * Xilinx calls it "PLB TFT LCD Controller" though it can also be used for
+ * the VGA port on the Xilinx ML40x board. This is a hardware display controller
+ * for a 640x480 resolution TFT or VGA screen.
+ *
+ * The interface to the framebuffer is nice and simple.  There are two
+ * control registers.  The first tells the LCD interface where in memory
+ * the frame buffer is (only the 11 most significant bits are used, so
+ * don't start thinking about scrolling).  The second allows the LCD to
+ * be turned on or off as well as rotated 180 degrees.
+ */
+#define NUM_REGS	2
+#define REG_FB_ADDR	0
+#define REG_CTRL	1
+#define REG_CTRL_ENABLE	 0x0001
+#define REG_CTRL_ROTATE	 0x0002
+
+/*
+ * The hardware only handles a single mode: 640x480 24 bit true
+ * color. Each pixel gets a word (32 bits) of memory.  Within each word,
+ * the 8 most significant bits are ignored, the next 8 bits are the red
+ * level, the next 8 bits are the green level and the 8 least
+ * significant bits are the blue level.  Each row of the LCD uses 1024
+ * words, but only the first 640 pixels are displayed with the other 384
+ * words being ignored.  There are 480 rows.
+ */
+#define BYTES_PER_PIXEL	4
+#define BITS_PER_PIXEL	(BYTES_PER_PIXEL * 8)
+#define XRES		640
+#define YRES		480
+#define XRES_VIRTUAL	1024
+#define YRES_VIRTUAL	YRES
+#define LINE_LENGTH	(XRES_VIRTUAL * BYTES_PER_PIXEL)
+#define FB_SIZE		(YRES_VIRTUAL * LINE_LENGTH)
+
+#define RED_SHIFT	16
+#define GREEN_SHIFT	8
+#define BLUE_SHIFT	0
+
+#define PALETTE_ENTRIES_NO	16	/* passed to fb_alloc_cmap() */
+
+/*
+ * Here are the default fb_fix_screeninfo and fb_var_screeninfo structures
+ */
+static struct fb_fix_screeninfo xilinx_fb_fix __initdata = {
+	.id =		"Xilinx",
+	.type =		FB_TYPE_PACKED_PIXELS,
+	.visual =	FB_VISUAL_TRUECOLOR,
+	.smem_len =	FB_SIZE,
+	.line_length =	LINE_LENGTH,
+	.accel =	FB_ACCEL_NONE
+};
+
+static struct fb_var_screeninfo xilinx_fb_var __initdata = {
+	.xres =			XRES,
+	.yres =			YRES,
+	.xres_virtual =		XRES_VIRTUAL,
+	.yres_virtual =		YRES_VIRTUAL,
+
+	.bits_per_pixel =	BITS_PER_PIXEL,
+
+	.red =		{ RED_SHIFT, 8, 0 },
+	.green =	{ GREEN_SHIFT, 8, 0 },
+	.blue =		{ BLUE_SHIFT, 8, 0 },
+	.transp =	{ 0, 0, 0 },
+
+	.activate =	FB_ACTIVATE_NOW
+};
+
+struct xilinxfb_drvdata {
+
+	struct fb_info	info;		/* FB driver info record */
+
+	u32		regs_phys;	/* phys. address of the control registers */
+	u32 __iomem	*regs;		/* virt. address of the control registers */
+
+	unsigned char __iomem	*fb_virt;	/* virt. address of the frame buffer */
+	dma_addr_t	fb_phys;	/* phys. address of the frame buffer */
+
+	u32		reg_ctrl_default;
+
+	u32		pseudo_palette[PALETTE_ENTRIES_NO];
+					/* Fake palette of 16 colors */
+};
+
+#define to_xilinxfb_drvdata(_info) \
+	container_of(_info, struct xilinxfb_drvdata, info)
+
+/*
+ * The LCD controller has DCR interface to its registers, but all
+ * the boards and configurations the driver has been tested with
+ * use opb2dcr bridge. So the registers are seen as memory mapped.
+ * This macro is to make it simple to add the direct DCR access
+ * when it's needed.
+ */
+#define xilinx_fb_out_be32(driverdata, offset, val) \
+	out_be32(driverdata->regs + offset, val)
+
+static int
+xilinx_fb_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue,
+	unsigned transp, struct fb_info *fbi)
+{
+	u32 *palette = fbi->pseudo_palette;
+
+	if (regno >= PALETTE_ENTRIES_NO)
+		return -EINVAL;
+
+	if (fbi->var.grayscale) {
+		/* Convert color to grayscale.
+		 * grayscale = 0.30*R + 0.59*G + 0.11*B */
+		red = green = blue =
+			(red * 77 + green * 151 + blue * 28 + 127) >> 8;
+	}
+
+	/* fbi->fix.visual is always FB_VISUAL_TRUECOLOR */
+
+	/* We only handle 8 bits of each color. */
+	red >>= 8;
+	green >>= 8;
+	blue >>= 8;
+	palette[regno] = (red << RED_SHIFT) | (green << GREEN_SHIFT) |
+			 (blue << BLUE_SHIFT);
+
+	return 0;
+}
+
+static int
+xilinx_fb_blank(int blank_mode, struct fb_info *fbi)
+{
+	struct xilinxfb_drvdata *drvdata = to_xilinxfb_drvdata(fbi);
+
+	switch (blank_mode) {
+	case FB_BLANK_UNBLANK:
+		/* turn on panel */
+		xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);
+		break;
+
+	case FB_BLANK_NORMAL:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_POWERDOWN:
+		/* turn off panel */
+		xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
+	default:
+		break;
+
+	}
+	return 0; /* success */
+}
+
+static struct fb_ops xilinxfb_ops =
+{
+	.owner			= THIS_MODULE,
+	.fb_setcolreg		= xilinx_fb_setcolreg,
+	.fb_blank		= xilinx_fb_blank,
+	.fb_fillrect		= cfb_fillrect,
+	.fb_copyarea		= cfb_copyarea,
+	.fb_imageblit		= cfb_imageblit,
+};
+
+/* === The device driver === */
+
+static int
+xilinxfb_drv_probe(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct xilinxfb_platform_data *pdata;
+	struct xilinxfb_drvdata *drvdata;
+	struct resource *regs_res;
+	int retval;
+
+	if (!dev)
+		return -EINVAL;
+
+	pdev = to_platform_device(dev);
+	pdata = pdev->dev.platform_data;
+
+	if (pdata == NULL) {
+		printk(KERN_ERR "Couldn't find platform data.\n");
+		return -EFAULT;
+	}
+
+	drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata) {
+		printk(KERN_ERR "Couldn't allocate device private record\n");
+		return -ENOMEM;
+	}
+	dev_set_drvdata(dev, drvdata);
+
+	/* Map the control registers in */
+	regs_res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!regs_res || (regs_res->end - regs_res->start + 1 < 8)) {
+		printk(KERN_ERR "Couldn't get registers resource\n");
+		retval = -EFAULT;
+		goto failed1;
+	}
+
+	if (!request_mem_region(regs_res->start, 8, DRIVER_NAME)) {
+		printk(KERN_ERR
+		       "Couldn't lock memory region at 0x%08X\n",
+		       regs_res->start);
+		retval = -EBUSY;
+		goto failed1;
+	}
+	drvdata->regs = (u32 __iomem*) ioremap(regs_res->start, 8);
+	drvdata->regs_phys = regs_res->start;
+
+	/* Allocate the framebuffer memory */
+	drvdata->fb_virt = dma_alloc_coherent(dev, PAGE_ALIGN(FB_SIZE),
+				&drvdata->fb_phys, GFP_KERNEL);
+	if (!drvdata->fb_virt) {
+		printk(KERN_ERR "Could not allocate frame buffer memory\n");
+		retval = -ENOMEM;
+		goto failed2;
+	}
+
+	/* Clear (turn to black) the framebuffer */
+	memset_io((void *) drvdata->fb_virt, 0, FB_SIZE);
+
+	/* Tell the hardware where the frame buffer is */
+	xilinx_fb_out_be32(drvdata, REG_FB_ADDR, drvdata->fb_phys);
+
+	/* Turn on the display */
+	if (pdata->rotate_screen) {
+		drvdata->reg_ctrl_default = REG_CTRL_ENABLE | REG_CTRL_ROTATE;
+	} else {
+		drvdata->reg_ctrl_default = REG_CTRL_ENABLE;
+	}
+	xilinx_fb_out_be32(drvdata, REG_CTRL, drvdata->reg_ctrl_default);
+
+	/* Fill struct fb_info */
+	drvdata->info.device = dev;
+	drvdata->info.screen_base = drvdata->fb_virt;
+	drvdata->info.fbops = &xilinxfb_ops;
+	drvdata->info.fix = xilinx_fb_fix;
+	drvdata->info.fix.smem_start = drvdata->fb_phys;
+	drvdata->info.pseudo_palette = drvdata->pseudo_palette;
+
+	if (fb_alloc_cmap(&drvdata->info.cmap, PALETTE_ENTRIES_NO, 0) < 0) {
+		printk(KERN_ERR "Fail to allocate colormap (%d entries)\n",
+			PALETTE_ENTRIES_NO);
+		retval = -EFAULT;
+		goto failed3;
+	}
+
+	drvdata->info.flags = FBINFO_DEFAULT;
+	xilinx_fb_var.height = pdata->screen_height_mm;
+	xilinx_fb_var.width = pdata->screen_width_mm;
+	drvdata->info.var = xilinx_fb_var;
+
+	/* Register new frame buffer */
+	if (register_framebuffer(&drvdata->info) < 0) {
+		printk(KERN_ERR "Could not register frame buffer\n");
+		retval = -EINVAL;
+		goto failed4;
+	}
+
+	return 0;	/* success */
+
+failed4:
+	fb_dealloc_cmap(&drvdata->info.cmap);
+
+failed3:
+	dma_free_coherent(dev, PAGE_ALIGN(FB_SIZE), drvdata->fb_virt,
+		drvdata->fb_phys);
+
+	/* Turn off the display */
+	xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
+	iounmap(drvdata->regs);
+
+failed2:
+	release_mem_region(regs_res->start, 8);
+
+failed1:
+	kfree(drvdata);
+	dev_set_drvdata(dev, NULL);
+
+	return retval;
+}
+
+static int
+xilinxfb_drv_remove(struct device *dev)
+{
+	struct xilinxfb_drvdata *drvdata;
+
+	if (!dev)
+		return -ENODEV;
+
+	drvdata = (struct xilinxfb_drvdata *) dev_get_drvdata(dev);
+
+#if !defined(CONFIG_FRAMEBUFFER_CONSOLE) && defined(CONFIG_LOGO)
+	xilinx_fb_blank(VESA_POWERDOWN, &drvdata->info);
+#endif
+
+	unregister_framebuffer(&drvdata->info);
+
+	fb_dealloc_cmap(&drvdata->info.cmap);
+
+	dma_free_coherent(dev, PAGE_ALIGN(FB_SIZE), drvdata->fb_virt,
+		drvdata->fb_phys);
+
+	/* Turn off the display */
+	xilinx_fb_out_be32(drvdata, REG_CTRL, 0);
+	iounmap(drvdata->regs);
+
+	release_mem_region(drvdata->regs_phys, 8);
+
+	kfree(drvdata);
+	dev_set_drvdata(dev, NULL);
+
+	return 0;
+}
+
+
+static struct device_driver xilinxfb_driver = {
+	.name		= DRIVER_NAME,
+	.bus		= &platform_bus_type,
+
+	.probe		= xilinxfb_drv_probe,
+	.remove		= xilinxfb_drv_remove
+};
+
+static int __init
+xilinxfb_init(void)
+{
+	/*
+	 * No kernel boot options used,
+	 * so we just need to register the driver
+	 */
+	return driver_register(&xilinxfb_driver);
+}
+
+static void __exit
+xilinxfb_cleanup(void)
+{
+	driver_unregister(&xilinxfb_driver);
+}
+
+module_init(xilinxfb_init);
+module_exit(xilinxfb_cleanup);
+
+MODULE_AUTHOR("MontaVista Software, Inc. <[email-masked]>");
+MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
+MODULE_LICENSE("GPL");
Index: linux-2.6.20/arch/ppc/syslib/virtex_devices.h
===================================================================
--- linux-2.6.20.orig/arch/ppc/syslib/virtex_devices.h
+++ linux-2.6.20/arch/ppc/syslib/virtex_devices.h
@@ -13,6 +13,13 @@

  #include <linux/platform_device.h>

+/* ML300/403 reference design framebuffer driver platform data struct */
+struct xilinxfb_platform_data {
+	u32 rotate_screen;
+	u32 screen_height_mm;
+	u32 screen_width_mm;
+};
+
  void __init virtex_early_serial_map(void);

  /* Prototype for device fixup routine.  Implement this routine in the
===8<===

Thanks,
Andrei