bcm2708 framebuffer driver

Signed-off-by: popcornmix <popcornmix@gmail.com>

bcm2708_fb : Implement blanking support using the mailbox property interface

bcm2708_fb: Add pan and vsync controls

bcm2708_fb: DMA acceleration for fb_copyarea

Based on http://www.raspberrypi.org/phpBB3/viewtopic.php?p=62425#p62425
Also used Simon's dmaer_master module as a reference for tweaking DMA
settings for better performance.

For now busylooping only. IRQ support might be added later.
With non-overclocked Raspberry Pi, the performance is ~360 MB/s
for simple copy or ~260 MB/s for two-pass copy (used when dragging
windows to the right).

In the case of using DMA channel 0, the performance improves
to ~440 MB/s.

For comparison, VFP optimized CPU copy can only do ~114 MB/s in
the same conditions (hindered by reading uncached source buffer).

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

bcm2708_fb: report number of dma copies

Add a counter (exported via debugfs) reporting the
number of dma copies that the framebuffer driver
has done, in order to help evaluate different
optimization strategies.

Signed-off-by: Luke Diamand <luked@broadcom.com>

bcm2708_fb: use IRQ for DMA copies

The copyarea ioctl() uses DMA to speed things along. This
was busy-waiting for completion. This change supports using
an interrupt instead for larger transfers. For small
transfers, busy-waiting is still likely to be faster.

Signed-off-by: Luke Diamand <luke@diamand.org>

bcm2708: Make ioctl logging quieter

video: fbdev: bcm2708_fb: Don't panic on error

No need to panic the kernel if the video driver fails.
Just print a message and return an error.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

fbdev: bcm2708_fb: Add ARCH_BCM2835 support

Add Device Tree support.
Pass the device to dma_alloc_coherent() in order to get the
correct bus address on ARCH_BCM2835.
Use the new DMA legacy API header file.
Including <mach/platform.h> is not necessary.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

BCM270x_DT: Add bcm2708-fb device

Add bcm2708-fb to Device Tree and don't add the
platform device when booting in DT mode.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Cleanup of bcm2708_fb file to kernel coding standards

Some minor change to function - remove a use of
in_atomic, plus replacing various debug messages
that manually specify the function name with
("%s",.__func__)

Signed-off-by: James Hughes <james.hughes@raspberrypi.org>

video: bcm2708_fb: Try allocating on the ARM and passing to VPU

Currently the VPU allocates the contiguous buffer for the
framebuffer.
Try an alternate path first where we use dma_alloc_coherent
and pass the buffer to the VPU. Should the VPU firmware not
support that path, then free the buffer and revert to the
old behaviour of using the VPU allocation.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>

drivers/video/fbdev/Kconfig

@@ -219,6 +219,20 @@ config FB_TILEBLITTING
 comment "Frame buffer hardware drivers"
 	depends on FB
 
+config FB_BCM2708
+	tristate "BCM2708 framebuffer support"
+	depends on FB && RASPBERRYPI_FIRMWARE
+	select FB_CFB_FILLRECT
+	select FB_CFB_COPYAREA
+	select FB_CFB_IMAGEBLIT
+	help
+	  This framebuffer device driver is for the BCM2708 framebuffer.
+
+	  If you want to compile this as a module (=code which can be
+	  inserted into and removed from the running kernel), say M
+	  here and read <file:Documentation/kbuild/modules.txt>.  The module
+	  will be called bcm2708_fb.
+
 config FB_GRVGA
 	tristate "Aeroflex Gaisler framebuffer support"
 	depends on FB && SPARC

drivers/video/fbdev/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_FB_MACMODES)      += macmodes.o
 obj-$(CONFIG_FB_WMT_GE_ROPS)   += wmt_ge_rops.o
 
 # Hardware specific drivers go first
+obj-$(CONFIG_FB_BCM2708)	  += bcm2708_fb.o
 obj-$(CONFIG_FB_AMIGA)            += amifb.o c2p_planar.o
 obj-$(CONFIG_FB_ARC)              += arcfb.o
 obj-$(CONFIG_FB_CLPS711X)	  += clps711x-fb.o

drivers/video/fbdev/bcm2708_fb.c

@@ -0,0 +1,920 @@
+/*
+ *  linux/drivers/video/bcm2708_fb.c
+ *
+ * Copyright (C) 2010 Broadcom
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * Broadcom simple framebuffer driver
+ *
+ * This file is derived from cirrusfb.c
+ * Copyright 1999-2001 Jeff Garzik <jgarzik@pobox.com>
+ *
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/list.h>
+#include <linux/platform_data/dma-bcm2708.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/printk.h>
+#include <linux/console.h>
+#include <linux/debugfs.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
+//#define BCM2708_FB_DEBUG
+#define MODULE_NAME "bcm2708_fb"
+
+#ifdef BCM2708_FB_DEBUG
+#define print_debug(fmt, ...) pr_debug("%s:%s:%d: " fmt, \
+			MODULE_NAME, __func__, __LINE__, ##__VA_ARGS__)
+#else
+#define print_debug(fmt, ...)
+#endif
+
+/* This is limited to 16 characters when displayed by X startup */
+static const char *bcm2708_name = "BCM2708 FB";
+
+#define DRIVER_NAME "bcm2708_fb"
+
+static int fbwidth = 800;	/* module parameter */
+static int fbheight = 480;	/* module parameter */
+static int fbdepth = 32;	/* module parameter */
+static int fbswap;		/* module parameter */
+
+static u32 dma_busy_wait_threshold = 1 << 15;
+module_param(dma_busy_wait_threshold, int, 0644);
+MODULE_PARM_DESC(dma_busy_wait_threshold, "Busy-wait for DMA completion below this area");
+
+struct fb_alloc_tags {
+	struct rpi_firmware_property_tag_header tag1;
+	u32 xres, yres;
+	struct rpi_firmware_property_tag_header tag2;
+	u32 xres_virtual, yres_virtual;
+	struct rpi_firmware_property_tag_header tag3;
+	u32 bpp;
+	struct rpi_firmware_property_tag_header tag4;
+	u32 xoffset, yoffset;
+	struct rpi_firmware_property_tag_header tag5;
+	u32 base, screen_size;
+	struct rpi_firmware_property_tag_header tag6;
+	u32 pitch;
+};
+
+struct bcm2708_fb_stats {
+	struct debugfs_regset32 regset;
+	u32 dma_copies;
+	u32 dma_irqs;
+};
+
+struct bcm2708_fb {
+	struct fb_info fb;
+	struct platform_device *dev;
+	struct rpi_firmware *fw;
+	u32 cmap[16];
+	u32 gpu_cmap[256];
+	int dma_chan;
+	int dma_irq;
+	void __iomem *dma_chan_base;
+	void *cb_base;		/* DMA control blocks */
+	dma_addr_t cb_handle;
+	struct dentry *debugfs_dir;
+	wait_queue_head_t dma_waitq;
+	struct bcm2708_fb_stats stats;
+	unsigned long fb_bus_address;
+	bool disable_arm_alloc;
+	unsigned int image_size;
+	dma_addr_t dma_addr;
+	void *cpuaddr;
+};
+
+#define to_bcm2708(info)	container_of(info, struct bcm2708_fb, fb)
+
+static void bcm2708_fb_debugfs_deinit(struct bcm2708_fb *fb)
+{
+	debugfs_remove_recursive(fb->debugfs_dir);
+	fb->debugfs_dir = NULL;
+}
+
+static int bcm2708_fb_debugfs_init(struct bcm2708_fb *fb)
+{
+	static struct debugfs_reg32 stats_registers[] = {
+		{
+			"dma_copies",
+			offsetof(struct bcm2708_fb_stats, dma_copies)
+		},
+		{
+			"dma_irqs",
+			offsetof(struct bcm2708_fb_stats, dma_irqs)
+		},
+	};
+
+	fb->debugfs_dir = debugfs_create_dir(DRIVER_NAME, NULL);
+	if (!fb->debugfs_dir) {
+		pr_warn("%s: could not create debugfs entry\n",
+			__func__);
+		return -EFAULT;
+	}
+
+	fb->stats.regset.regs = stats_registers;
+	fb->stats.regset.nregs = ARRAY_SIZE(stats_registers);
+	fb->stats.regset.base = &fb->stats;
+
+	debugfs_create_regset32("stats", 0444, fb->debugfs_dir,
+				&fb->stats.regset);
+	return 0;
+}
+
+static int bcm2708_fb_set_bitfields(struct fb_var_screeninfo *var)
+{
+	int ret = 0;
+
+	memset(&var->transp, 0, sizeof(var->transp));
+
+	var->red.msb_right = 0;
+	var->green.msb_right = 0;
+	var->blue.msb_right = 0;
+
+	switch (var->bits_per_pixel) {
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+		var->red.length = var->bits_per_pixel;
+		var->red.offset = 0;
+		var->green.length = var->bits_per_pixel;
+		var->green.offset = 0;
+		var->blue.length = var->bits_per_pixel;
+		var->blue.offset = 0;
+		break;
+	case 16:
+		var->red.length = 5;
+		var->blue.length = 5;
+		/*
+		 * Green length can be 5 or 6 depending whether
+		 * we're operating in RGB555 or RGB565 mode.
+		 */
+		if (var->green.length != 5 && var->green.length != 6)
+			var->green.length = 6;
+		break;
+	case 24:
+		var->red.length = 8;
+		var->blue.length = 8;
+		var->green.length = 8;
+		break;
+	case 32:
+		var->red.length = 8;
+		var->green.length = 8;
+		var->blue.length = 8;
+		var->transp.length = 8;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	/*
+	 * >= 16bpp displays have separate colour component bitfields
+	 * encoded in the pixel data.  Calculate their position from
+	 * the bitfield length defined above.
+	 */
+	if (ret == 0 && var->bits_per_pixel >= 24 && fbswap) {
+		var->blue.offset = 0;
+		var->green.offset = var->blue.offset + var->blue.length;
+		var->red.offset = var->green.offset + var->green.length;
+		var->transp.offset = var->red.offset + var->red.length;
+	} else if (ret == 0 && var->bits_per_pixel >= 24) {
+		var->red.offset = 0;
+		var->green.offset = var->red.offset + var->red.length;
+		var->blue.offset = var->green.offset + var->green.length;
+		var->transp.offset = var->blue.offset + var->blue.length;
+	} else if (ret == 0 && var->bits_per_pixel >= 16) {
+		var->blue.offset = 0;
+		var->green.offset = var->blue.offset + var->blue.length;
+		var->red.offset = var->green.offset + var->green.length;
+		var->transp.offset = var->red.offset + var->red.length;
+	}
+
+	return ret;
+}
+
+static int bcm2708_fb_check_var(struct fb_var_screeninfo *var,
+				struct fb_info *info)
+{
+	/* info input, var output */
+	print_debug("%s(%p) %dx%d (%dx%d), %d, %d\n",
+		    __func__, info, info->var.xres, info->var.yres,
+		    info->var.xres_virtual, info->var.yres_virtual,
+		    (int)info->screen_size, info->var.bits_per_pixel);
+	print_debug("%s(%p) %dx%d (%dx%d), %d\n", __func__, var, var->xres,
+		    var->yres, var->xres_virtual, var->yres_virtual,
+		    var->bits_per_pixel);
+
+	if (!var->bits_per_pixel)
+		var->bits_per_pixel = 16;
+
+	if (bcm2708_fb_set_bitfields(var) != 0) {
+		pr_err("%s: invalid bits_per_pixel %d\n", __func__,
+		       var->bits_per_pixel);
+		return -EINVAL;
+	}
+
+	if (var->xres_virtual < var->xres)
+		var->xres_virtual = var->xres;
+	/* use highest possible virtual resolution */
+	if (var->yres_virtual == -1) {
+		var->yres_virtual = 480;
+
+		pr_err("%s: virtual resolution set to maximum of %dx%d\n",
+		       __func__, var->xres_virtual, var->yres_virtual);
+	}
+	if (var->yres_virtual < var->yres)
+		var->yres_virtual = var->yres;
+
+	if (var->xoffset < 0)
+		var->xoffset = 0;
+	if (var->yoffset < 0)
+		var->yoffset = 0;
+
+	/* truncate xoffset and yoffset to maximum if too high */
+	if (var->xoffset > var->xres_virtual - var->xres)
+		var->xoffset = var->xres_virtual - var->xres - 1;
+	if (var->yoffset > var->yres_virtual - var->yres)
+		var->yoffset = var->yres_virtual - var->yres - 1;
+
+	return 0;
+}
+
+static int bcm2708_fb_set_par(struct fb_info *info)
+{
+	struct bcm2708_fb *fb = to_bcm2708(info);
+	struct fb_alloc_tags fbinfo = {
+		.tag1 = { RPI_FIRMWARE_FRAMEBUFFER_SET_PHYSICAL_WIDTH_HEIGHT,
+			  8, 0, },
+			.xres = info->var.xres,
+			.yres = info->var.yres,
+		.tag2 = { RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_WIDTH_HEIGHT,
+			  8, 0, },
+			.xres_virtual = info->var.xres_virtual,
+			.yres_virtual = info->var.yres_virtual,
+		.tag3 = { RPI_FIRMWARE_FRAMEBUFFER_SET_DEPTH, 4, 0 },
+			.bpp = info->var.bits_per_pixel,
+		.tag4 = { RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_OFFSET, 8, 0 },
+			.xoffset = info->var.xoffset,
+			.yoffset = info->var.yoffset,
+		.tag5 = { RPI_FIRMWARE_FRAMEBUFFER_ALLOCATE, 8, 0 },
+			/* base and screen_size will be initialised later */
+		.tag6 = { RPI_FIRMWARE_FRAMEBUFFER_SET_PITCH, 4, 0 },
+			/* pitch will be initialised later */
+	};
+	int ret, image_size;
+
+
+	print_debug("%s(%p) %dx%d (%dx%d), %d, %d\n", __func__, info,
+		    info->var.xres, info->var.yres, info->var.xres_virtual,
+		    info->var.yres_virtual, (int)info->screen_size,
+		    info->var.bits_per_pixel);
+
+	/* Try allocating our own buffer. We can specify all the parameters */
+	image_size = ((info->var.xres * info->var.yres) *
+		      info->var.bits_per_pixel) >> 3;
+
+	if (!fb->disable_arm_alloc &&
+	    (image_size != fb->image_size || !fb->dma_addr)) {
+		if (fb->dma_addr) {
+			dma_free_coherent(info->device, fb->image_size,
+					  fb->cpuaddr, fb->dma_addr);
+			fb->image_size = 0;
+			fb->cpuaddr = NULL;
+			fb->dma_addr = 0;
+		}
+
+		fb->cpuaddr = dma_alloc_coherent(info->device, image_size,
+						 &fb->dma_addr, GFP_KERNEL);
+
+		if (!fb->cpuaddr) {
+			fb->dma_addr = 0;
+			fb->disable_arm_alloc = true;
+		} else {
+			fb->image_size = image_size;
+		}
+	}
+
+	if (fb->cpuaddr) {
+		fbinfo.base = fb->dma_addr;
+		fbinfo.screen_size = image_size;
+		fbinfo.pitch = (info->var.xres * info->var.bits_per_pixel) >> 3;
+
+		ret = rpi_firmware_property_list(fb->fw, &fbinfo,
+						 sizeof(fbinfo));
+		if (ret || fbinfo.base != fb->dma_addr) {
+			/* Firmware either failed, or assigned a different base
+			 * address (ie it doesn't support being passed an FB
+			 * allocation).
+			 * Destroy the allocation, and don't try again.
+			 */
+			dma_free_coherent(info->device, fb->image_size,
+					  fb->cpuaddr, fb->dma_addr);
+			fb->image_size = 0;
+			fb->cpuaddr = NULL;
+			fb->dma_addr = 0;
+			fb->disable_arm_alloc = true;
+		}
+	} else {
+		/* Our allocation failed - drop into the old scheme of
+		 * allocation by the VPU.
+		 */
+		ret = -ENOMEM;
+	}
+
+	if (ret) {
+		/* Old scheme:
+		 * - FRAMEBUFFER_ALLOCATE passes 0 for base and screen_size.
+		 * - GET_PITCH instead of SET_PITCH.
+		 */
+		fbinfo.base = 0;
+		fbinfo.screen_size = 0;
+		fbinfo.tag6.tag = RPI_FIRMWARE_FRAMEBUFFER_GET_PITCH;
+		fbinfo.pitch = 0;
+
+		ret = rpi_firmware_property_list(fb->fw, &fbinfo,
+						 sizeof(fbinfo));
+		if (ret) {
+			dev_err(info->device,
+				"Failed to allocate GPU framebuffer (%d)\n",
+				ret);
+			return ret;
+		}
+	}
+
+	if (info->var.bits_per_pixel <= 8)
+		fb->fb.fix.visual = FB_VISUAL_PSEUDOCOLOR;
+	else
+		fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
+
+	fb->fb.fix.line_length = fbinfo.pitch;
+	fbinfo.base |= 0x40000000;
+	fb->fb_bus_address = fbinfo.base;
+	fbinfo.base &= ~0xc0000000;
+	fb->fb.fix.smem_start = fbinfo.base;
+	fb->fb.fix.smem_len = fbinfo.pitch * fbinfo.yres_virtual;
+	fb->fb.screen_size = fbinfo.screen_size;
+
+	if (!fb->dma_addr) {
+		if (fb->fb.screen_base)
+			iounmap(fb->fb.screen_base);
+
+		fb->fb.screen_base = ioremap_wc(fbinfo.base,
+						fb->fb.screen_size);
+	} else {
+		fb->fb.screen_base = fb->cpuaddr;
+	}
+
+	if (!fb->fb.screen_base) {
+		/* the console may currently be locked */
+		console_trylock();
+		console_unlock();
+		dev_err(info->device, "Failed to set screen_base\n");
+		return -ENOMEM;
+	}
+
+	print_debug("%s: start = %p,%p width=%d, height=%d, bpp=%d, pitch=%d size=%d\n",
+		    __func__, (void *)fb->fb.screen_base,
+		    (void *)fb->fb_bus_address, fbinfo.xres, fbinfo.yres,
+		    fbinfo.bpp, fbinfo.pitch, (int)fb->fb.screen_size);
+
+	return 0;
+}
+
+static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
+{
+	unsigned int mask = (1 << bf->length) - 1;
+
+	return (val >> (16 - bf->length) & mask) << bf->offset;
+}
+
+static int bcm2708_fb_setcolreg(unsigned int regno, unsigned int red,
+				unsigned int green, unsigned int blue,
+				unsigned int transp, struct fb_info *info)
+{
+	struct bcm2708_fb *fb = to_bcm2708(info);
+
+	if (fb->fb.var.bits_per_pixel <= 8) {
+		if (regno < 256) {
+			/* blue [23:16], green [15:8], red [7:0] */
+			fb->gpu_cmap[regno] = ((red   >> 8) & 0xff) << 0 |
+					      ((green >> 8) & 0xff) << 8 |
+					      ((blue  >> 8) & 0xff) << 16;
+		}
+		/* Hack: we need to tell GPU the palette has changed, but
+		 * currently bcm2708_fb_set_par takes noticeable time when
+		 * called for every (256) colour
+		 * So just call it for what looks like the last colour in a
+		 * list for now.
+		 */
+		if (regno == 15 || regno == 255) {
+			struct packet {
+				u32 offset;
+				u32 length;
+				u32 cmap[256];
+			} *packet;
+			int ret;
+
+			packet = kmalloc(sizeof(*packet), GFP_KERNEL);
+			if (!packet)
+				return -ENOMEM;
+			packet->offset = 0;
+			packet->length = regno + 1;
+			memcpy(packet->cmap, fb->gpu_cmap,
+			       sizeof(packet->cmap));
+			ret = rpi_firmware_property(fb->fw,
+						    RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE,
+						    packet,
+						    (2 + packet->length) * sizeof(u32));
+			if (ret || packet->offset)
+				dev_err(info->device,
+					"Failed to set palette (%d,%u)\n",
+					ret, packet->offset);
+			kfree(packet);
+		}
+	} else if (regno < 16) {
+		fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) |
+				  convert_bitfield(blue, &fb->fb.var.blue) |
+				  convert_bitfield(green, &fb->fb.var.green) |
+				  convert_bitfield(red, &fb->fb.var.red);
+	}
+	return regno > 255;
+}
+
+static int bcm2708_fb_blank(int blank_mode, struct fb_info *info)
+{
+	struct bcm2708_fb *fb = to_bcm2708(info);
+	u32 value;
+	int ret;
+
+	switch (blank_mode) {
+	case FB_BLANK_UNBLANK:
+		value = 0;
+		break;
+	case FB_BLANK_NORMAL:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_POWERDOWN:
+		value = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = rpi_firmware_property(fb->fw, RPI_FIRMWARE_FRAMEBUFFER_BLANK,
+				    &value, sizeof(value));
+	if (ret)
+		dev_err(info->device, "%s(%d) failed: %d\n", __func__,
+			blank_mode, ret);
+
+	return ret;
+}
+
+static int bcm2708_fb_pan_display(struct fb_var_screeninfo *var,
+				  struct fb_info *info)
+{
+	s32 result;
+
+	info->var.xoffset = var->xoffset;
+	info->var.yoffset = var->yoffset;
+	result = bcm2708_fb_set_par(info);
+	if (result != 0)
+		pr_err("%s(%d,%d) returns=%d\n", __func__, var->xoffset,
+		       var->yoffset, result);
+	return result;
+}
+
+static int bcm2708_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
+{
+	struct bcm2708_fb *fb = to_bcm2708(info);
+	u32 dummy = 0;
+	int ret;
+
+	switch (cmd) {
+	case FBIO_WAITFORVSYNC:
+		ret = rpi_firmware_property(fb->fw,
+					    RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC,
+					    &dummy, sizeof(dummy));
+		break;
+	default:
+		dev_dbg(info->device, "Unknown ioctl 0x%x\n", cmd);
+		return -ENOTTY;
+	}
+
+	if (ret)
+		dev_err(info->device, "ioctl 0x%x failed (%d)\n", cmd, ret);
+
+	return ret;
+}
+static void bcm2708_fb_fillrect(struct fb_info *info,
+				const struct fb_fillrect *rect)
+{
+	/* (is called) print_debug("bcm2708_fb_fillrect\n"); */
+	cfb_fillrect(info, rect);
+}
+
+/* A helper function for configuring dma control block */
+static void set_dma_cb(struct bcm2708_dma_cb *cb,
+		       int        burst_size,
+		       dma_addr_t dst,
+		       int        dst_stride,
+		       dma_addr_t src,
+		       int        src_stride,
+		       int        w,
+		       int        h)
+{
+	cb->info = BCM2708_DMA_BURST(burst_size) | BCM2708_DMA_S_WIDTH |
+		   BCM2708_DMA_S_INC | BCM2708_DMA_D_WIDTH |
+		   BCM2708_DMA_D_INC | BCM2708_DMA_TDMODE;
+	cb->dst = dst;
+	cb->src = src;
+	/*
+	 * This is not really obvious from the DMA documentation,
+	 * but the top 16 bits must be programmmed to "height -1"
+	 * and not "height" in 2D mode.
+	 */
+	cb->length = ((h - 1) << 16) | w;
+	cb->stride = ((dst_stride - w) << 16) | (u16)(src_stride - w);
+	cb->pad[0] = 0;
+	cb->pad[1] = 0;
+}
+
+static void bcm2708_fb_copyarea(struct fb_info *info,
+				const struct fb_copyarea *region)
+{
+	struct bcm2708_fb *fb = to_bcm2708(info);
+	struct bcm2708_dma_cb *cb = fb->cb_base;
+	int bytes_per_pixel = (info->var.bits_per_pixel + 7) >> 3;
+
+	/* Channel 0 supports larger bursts and is a bit faster */
+	int burst_size = (fb->dma_chan == 0) ? 8 : 2;
+	int pixels = region->width * region->height;
+
+	/* Fallback to cfb_copyarea() if we don't like something */
+	if (bytes_per_pixel > 4 ||
+	    info->var.xres * info->var.yres > 1920 * 1200 ||
+	    region->width <= 0 || region->width > info->var.xres ||
+	    region->height <= 0 || region->height > info->var.yres ||
+	    region->sx < 0 || region->sx >= info->var.xres ||
+	    region->sy < 0 || region->sy >= info->var.yres ||
+	    region->dx < 0 || region->dx >= info->var.xres ||
+	    region->dy < 0 || region->dy >= info->var.yres ||
+	    region->sx + region->width > info->var.xres ||
+	    region->dx + region->width > info->var.xres ||
+	    region->sy + region->height > info->var.yres ||
+	    region->dy + region->height > info->var.yres) {
+		cfb_copyarea(info, region);
+		return;
+	}
+
+	if (region->dy == region->sy && region->dx > region->sx) {
+		/*
+		 * A difficult case of overlapped copy. Because DMA can't
+		 * copy individual scanlines in backwards direction, we need
+		 * two-pass processing. We do it by programming a chain of dma
+		 * control blocks in the first 16K part of the buffer and use
+		 * the remaining 48K as the intermediate temporary scratch
+		 * buffer. The buffer size is sufficient to handle up to
+		 * 1920x1200 resolution at 32bpp pixel depth.
+		 */
+		int y;
+		dma_addr_t control_block_pa = fb->cb_handle;
+		dma_addr_t scratchbuf = fb->cb_handle + 16 * 1024;
+		int scanline_size = bytes_per_pixel * region->width;
+		int scanlines_per_cb = (64 * 1024 - 16 * 1024) / scanline_size;
+
+		for (y = 0; y < region->height; y += scanlines_per_cb) {
+			dma_addr_t src =
+				fb->fb_bus_address +
+				bytes_per_pixel * region->sx +
+				(region->sy + y) * fb->fb.fix.line_length;
+			dma_addr_t dst =
+				fb->fb_bus_address +
+				bytes_per_pixel * region->dx +
+				(region->dy + y) * fb->fb.fix.line_length;
+
+			if (region->height - y < scanlines_per_cb)
+				scanlines_per_cb = region->height - y;
+
+			set_dma_cb(cb, burst_size, scratchbuf, scanline_size,
+				   src, fb->fb.fix.line_length,
+				   scanline_size, scanlines_per_cb);
+			control_block_pa += sizeof(struct bcm2708_dma_cb);
+			cb->next = control_block_pa;
+			cb++;
+
+			set_dma_cb(cb, burst_size, dst, fb->fb.fix.line_length,
+				   scratchbuf, scanline_size,
+				   scanline_size, scanlines_per_cb);
+			control_block_pa += sizeof(struct bcm2708_dma_cb);
+			cb->next = control_block_pa;
+			cb++;
+		}
+		/* move the pointer back to the last dma control block */
+		cb--;
+	} else {
+		/* A single dma control block is enough. */
+		int sy, dy, stride;
+
+		if (region->dy <= region->sy) {
+			/* processing from top to bottom */
+			dy = region->dy;
+			sy = region->sy;
+			stride = fb->fb.fix.line_length;
+		} else {
+			/* processing from bottom to top */
+			dy = region->dy + region->height - 1;
+			sy = region->sy + region->height - 1;
+			stride = -fb->fb.fix.line_length;
+		}
+		set_dma_cb(cb, burst_size,
+			   fb->fb_bus_address + dy * fb->fb.fix.line_length +
+						   bytes_per_pixel * region->dx,
+			   stride,
+			   fb->fb_bus_address + sy * fb->fb.fix.line_length +
+						   bytes_per_pixel * region->sx,
+			   stride,
+			   region->width * bytes_per_pixel,
+			   region->height);
+	}
+
+	/* end of dma control blocks chain */
+	cb->next = 0;
+
+	if (pixels < dma_busy_wait_threshold) {
+		bcm_dma_start(fb->dma_chan_base, fb->cb_handle);
+		bcm_dma_wait_idle(fb->dma_chan_base);
+	} else {
+		void __iomem *dma_chan = fb->dma_chan_base;
+
+		cb->info |= BCM2708_DMA_INT_EN;
+		bcm_dma_start(fb->dma_chan_base, fb->cb_handle);
+		while (bcm_dma_is_busy(dma_chan)) {
+			wait_event_interruptible(fb->dma_waitq,
+						 !bcm_dma_is_busy(dma_chan));
+		}
+		fb->stats.dma_irqs++;
+	}
+	fb->stats.dma_copies++;
+}
+
+static void bcm2708_fb_imageblit(struct fb_info *info,
+				 const struct fb_image *image)
+{
+	/* (is called) print_debug("bcm2708_fb_imageblit\n"); */
+	cfb_imageblit(info, image);
+}
+
+static irqreturn_t bcm2708_fb_dma_irq(int irq, void *cxt)
+{
+	struct bcm2708_fb *fb = cxt;
+
+	/* FIXME: should read status register to check if this is
+	 * actually interrupting us or not, in case this interrupt
+	 * ever becomes shared amongst several DMA channels
+	 *
+	 * readl(dma_chan_base + BCM2708_DMA_CS) & BCM2708_DMA_IRQ;
+	 */
+
+	/* acknowledge the interrupt */
+	writel(BCM2708_DMA_INT, fb->dma_chan_base + BCM2708_DMA_CS);
+
+	wake_up(&fb->dma_waitq);
+	return IRQ_HANDLED;
+}
+
+static struct fb_ops bcm2708_fb_ops = {
+	.owner = THIS_MODULE,
+	.fb_check_var = bcm2708_fb_check_var,
+	.fb_set_par = bcm2708_fb_set_par,
+	.fb_setcolreg = bcm2708_fb_setcolreg,
+	.fb_blank = bcm2708_fb_blank,
+	.fb_fillrect = bcm2708_fb_fillrect,
+	.fb_copyarea = bcm2708_fb_copyarea,
+	.fb_imageblit = bcm2708_fb_imageblit,
+	.fb_pan_display = bcm2708_fb_pan_display,
+	.fb_ioctl = bcm2708_ioctl,
+};
+
+static int bcm2708_fb_register(struct bcm2708_fb *fb)
+{
+	int ret;
+
+	fb->fb.fbops = &bcm2708_fb_ops;
+	fb->fb.flags = FBINFO_FLAG_DEFAULT | FBINFO_HWACCEL_COPYAREA;
+	fb->fb.pseudo_palette = fb->cmap;
+
+	strncpy(fb->fb.fix.id, bcm2708_name, sizeof(fb->fb.fix.id));
+	fb->fb.fix.type = FB_TYPE_PACKED_PIXELS;
+	fb->fb.fix.type_aux = 0;
+	fb->fb.fix.xpanstep = 1;
+	fb->fb.fix.ypanstep = 1;
+	fb->fb.fix.ywrapstep = 0;
+	fb->fb.fix.accel = FB_ACCEL_NONE;
+
+	fb->fb.var.xres = fbwidth;
+	fb->fb.var.yres = fbheight;
+	fb->fb.var.xres_virtual = fbwidth;
+	fb->fb.var.yres_virtual = fbheight;
+	fb->fb.var.bits_per_pixel = fbdepth;
+	fb->fb.var.vmode = FB_VMODE_NONINTERLACED;
+	fb->fb.var.activate = FB_ACTIVATE_NOW;
+	fb->fb.var.nonstd = 0;
+	fb->fb.var.height = -1;		/* height of picture in mm    */
+	fb->fb.var.width = -1;		/* width of picture in mm    */
+	fb->fb.var.accel_flags = 0;
+
+	fb->fb.monspecs.hfmin = 0;
+	fb->fb.monspecs.hfmax = 100000;
+	fb->fb.monspecs.vfmin = 0;
+	fb->fb.monspecs.vfmax = 400;
+	fb->fb.monspecs.dclkmin = 1000000;
+	fb->fb.monspecs.dclkmax = 100000000;
+
+	bcm2708_fb_set_bitfields(&fb->fb.var);
+	init_waitqueue_head(&fb->dma_waitq);
+
+	/*
+	 * Allocate colourmap.
+	 */
+
+	fb_set_var(&fb->fb, &fb->fb.var);
+	ret = bcm2708_fb_set_par(&fb->fb);
+	if (ret)
+		return ret;
+
+	print_debug("BCM2708FB: registering framebuffer (%dx%d@%d) (%d)\n",
+		    fbwidth, fbheight, fbdepth, fbswap);
+
+	ret = register_framebuffer(&fb->fb);
+	print_debug("BCM2708FB: register framebuffer (%d)\n", ret);
+	if (ret == 0)
+		goto out;
+
+	print_debug("BCM2708FB: cannot register framebuffer (%d)\n", ret);
+out:
+	return ret;
+}
+
+static int bcm2708_fb_probe(struct platform_device *dev)
+{
+	struct device_node *fw_np;
+	struct rpi_firmware *fw;
+	struct bcm2708_fb *fb;
+	int ret;
+
+	fw_np = of_parse_phandle(dev->dev.of_node, "firmware", 0);
+/* Remove comment when booting without Device Tree is no longer supported
+ *	if (!fw_np) {
+ *		dev_err(&dev->dev, "Missing firmware node\n");
+ *		return -ENOENT;
+ *	}
+ */
+	fw = rpi_firmware_get(fw_np);
+	if (!fw)
+		return -EPROBE_DEFER;
+
+	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
+	if (!fb) {
+		ret = -ENOMEM;
+		goto free_region;
+	}
+
+	fb->fw = fw;
+	bcm2708_fb_debugfs_init(fb);
+
+	fb->cb_base = dma_alloc_wc(&dev->dev, SZ_64K,
+					     &fb->cb_handle, GFP_KERNEL);
+	if (!fb->cb_base) {
+		dev_err(&dev->dev, "cannot allocate DMA CBs\n");
+		ret = -ENOMEM;
+		goto free_fb;
+	}
+
+	pr_info("BCM2708FB: allocated DMA memory %pad\n", &fb->cb_handle);
+
+	ret = bcm_dma_chan_alloc(BCM_DMA_FEATURE_BULK,
+				 &fb->dma_chan_base, &fb->dma_irq);
+	if (ret < 0) {
+		dev_err(&dev->dev, "couldn't allocate a DMA channel\n");
+		goto free_cb;
+	}
+	fb->dma_chan = ret;
+
+	ret = request_irq(fb->dma_irq, bcm2708_fb_dma_irq,
+			  0, "bcm2708_fb dma", fb);
+	if (ret) {
+		pr_err("%s: failed to request DMA irq\n", __func__);
+		goto free_dma_chan;
+	}
+
+	pr_info("BCM2708FB: allocated DMA channel %d\n", fb->dma_chan);
+
+	fb->dev = dev;
+	fb->fb.device = &dev->dev;
+
+	/* failure here isn't fatal, but we'll fail in vc_mem_copy if
+	 * fb->gpu is not valid
+	 */
+	rpi_firmware_property(fb->fw, RPI_FIRMWARE_GET_VC_MEMORY, &fb->gpu,
+			      sizeof(fb->gpu));
+
+	ret = bcm2708_fb_register(fb);
+	if (ret == 0) {
+		platform_set_drvdata(dev, fb);
+		goto out;
+	}
+
+free_dma_chan:
+	bcm_dma_chan_free(fb->dma_chan);
+free_cb:
+	dma_free_wc(&dev->dev, SZ_64K, fb->cb_base, fb->cb_handle);
+free_fb:
+	kfree(fb);
+free_region:
+	dev_err(&dev->dev, "probe failed, err %d\n", ret);
+out:
+	return ret;
+}
+
+static int bcm2708_fb_remove(struct platform_device *dev)
+{
+	struct bcm2708_fb *fb = platform_get_drvdata(dev);
+
+	platform_set_drvdata(dev, NULL);
+
+	if (fb->fb.screen_base)
+		iounmap(fb->fb.screen_base);
+	unregister_framebuffer(&fb->fb);
+
+	dma_free_wc(&dev->dev, SZ_64K, fb->cb_base, fb->cb_handle);
+	bcm_dma_chan_free(fb->dma_chan);
+
+	bcm2708_fb_debugfs_deinit(fb);
+
+	free_irq(fb->dma_irq, fb);
+
+	kfree(fb);
+
+	return 0;
+}
+
+static const struct of_device_id bcm2708_fb_of_match_table[] = {
+	{ .compatible = "brcm,bcm2708-fb", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm2708_fb_of_match_table);
+
+static struct platform_driver bcm2708_fb_driver = {
+	.probe = bcm2708_fb_probe,
+	.remove = bcm2708_fb_remove,
+	.driver = {
+		   .name = DRIVER_NAME,
+		   .owner = THIS_MODULE,
+		   .of_match_table = bcm2708_fb_of_match_table,
+		   },
+};
+
+static int __init bcm2708_fb_init(void)
+{
+	return platform_driver_register(&bcm2708_fb_driver);
+}
+
+module_init(bcm2708_fb_init);
+
+static void __exit bcm2708_fb_exit(void)
+{
+	platform_driver_unregister(&bcm2708_fb_driver);
+}
+
+module_exit(bcm2708_fb_exit);
+
+module_param(fbwidth, int, 0644);
+module_param(fbheight, int, 0644);
+module_param(fbdepth, int, 0644);
+module_param(fbswap, int, 0644);
+
+MODULE_DESCRIPTION("BCM2708 framebuffer driver");
+MODULE_LICENSE("GPL");
+
+MODULE_PARM_DESC(fbwidth, "Width of ARM Framebuffer");
+MODULE_PARM_DESC(fbheight, "Height of ARM Framebuffer");
+MODULE_PARM_DESC(fbdepth, "Bit depth of ARM Framebuffer");
+MODULE_PARM_DESC(fbswap, "Swap order of red and blue in 24 and 32 bit modes");

include/soc/bcm2835/raspberrypi-firmware.h

@@ -123,6 +123,7 @@ enum rpi_firmware_property_tag {
 	RPI_FIRMWARE_FRAMEBUFFER_SET_DEPTH =                  0x00048005,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_PIXEL_ORDER =            0x00048006,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_ALPHA_MODE =             0x00048007,
+	RPI_FIRMWARE_FRAMEBUFFER_SET_PITCH =                  0x00048008,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_VIRTUAL_OFFSET =         0x00048009,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_OVERSCAN =               0x0004800a,
 	RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE =                0x0004800b,