Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 733 insertions, 0 deletions

diff --git a/drivers/video/fbdev/pxa3xx-gcu.c b/drivers/video/fbdev/pxa3xx-gcu.c
new file mode 100644
index 000000000..43695a33f
--- /dev/null
+++ b/drivers/video/fbdev/pxa3xx-gcu.c
@@ -0,0 +1,733 @@
+/*
+ *  pxa3xx-gcu.c - Linux kernel module for PXA3xx graphics controllers
+ *
+ *  This driver needs a DirectFB counterpart in user space, communication
+ *  is handled via mmap()ed memory areas and an ioctl.
+ *
+ *  Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
+ *  Copyright (c) 2009 Janine Kropp <nin@directfb.org>
+ *  Copyright (c) 2009 Denis Oliver Kropp <dok@directfb.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * WARNING: This controller is attached to System Bus 2 of the PXA which
+ * needs its arbiter to be enabled explicitly (CKENB & 1<<9).
+ * There is currently no way to do this from Linux, so you need to teach
+ * your bootloader for now.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/miscdevice.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/ioctl.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include "pxa3xx-gcu.h"
+
+#define DRV_NAME	"pxa3xx-gcu"
+#define MISCDEV_MINOR	197
+
+#define REG_GCCR	0x00
+#define GCCR_SYNC_CLR	(1 << 9)
+#define GCCR_BP_RST	(1 << 8)
+#define GCCR_ABORT	(1 << 6)
+#define GCCR_STOP	(1 << 4)
+
+#define REG_GCISCR	0x04
+#define REG_GCIECR	0x08
+#define REG_GCRBBR	0x20
+#define REG_GCRBLR	0x24
+#define REG_GCRBHR	0x28
+#define REG_GCRBTR	0x2C
+#define REG_GCRBEXHR	0x30
+
+#define IE_EOB		(1 << 0)
+#define IE_EEOB		(1 << 5)
+#define IE_ALL		0xff
+
+#define SHARED_SIZE	PAGE_ALIGN(sizeof(struct pxa3xx_gcu_shared))
+
+/* #define PXA3XX_GCU_DEBUG */
+/* #define PXA3XX_GCU_DEBUG_TIMER */
+
+#ifdef PXA3XX_GCU_DEBUG
+#define QDUMP(msg)					\
+	do {						\
+		QPRINT(priv, KERN_DEBUG, msg);		\
+	} while (0)
+#else
+#define QDUMP(msg)	do {} while (0)
+#endif
+
+#define QERROR(msg)					\
+	do {						\
+		QPRINT(priv, KERN_ERR, msg);		\
+	} while (0)
+
+struct pxa3xx_gcu_batch {
+	struct pxa3xx_gcu_batch *next;
+	u32			*ptr;
+	dma_addr_t		 phys;
+	unsigned long		 length;
+};
+
+struct pxa3xx_gcu_priv {
+	void __iomem		 *mmio_base;
+	struct clk		 *clk;
+	struct pxa3xx_gcu_shared *shared;
+	dma_addr_t		  shared_phys;
+	struct resource		 *resource_mem;
+	struct miscdevice	  misc_dev;
+	wait_queue_head_t	  wait_idle;
+	wait_queue_head_t	  wait_free;
+	spinlock_t		  spinlock;
+	struct timespec64	  base_time;
+
+	struct pxa3xx_gcu_batch *free;
+	struct pxa3xx_gcu_batch *ready;
+	struct pxa3xx_gcu_batch *ready_last;
+	struct pxa3xx_gcu_batch *running;
+};
+
+static inline unsigned long
+gc_readl(struct pxa3xx_gcu_priv *priv, unsigned int off)
+{
+	return __raw_readl(priv->mmio_base + off);
+}
+
+static inline void
+gc_writel(struct pxa3xx_gcu_priv *priv, unsigned int off, unsigned long val)
+{
+	__raw_writel(val, priv->mmio_base + off);
+}
+
+#define QPRINT(priv, level, msg)					\
+	do {								\
+		struct timespec64 ts;					\
+		struct pxa3xx_gcu_shared *shared = priv->shared;	\
+		u32 base = gc_readl(priv, REG_GCRBBR);			\
+									\
+		ktime_get_ts64(&ts);					\
+		ts = timespec64_sub(ts, priv->base_time);		\
+									\
+		printk(level "%lld.%03ld.%03ld - %-17s: %-21s (%s, "	\
+			"STATUS "					\
+			"0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, "	\
+			"T %5ld)\n",					\
+			(s64)(ts.tv_sec),				\
+			ts.tv_nsec / NSEC_PER_MSEC,			\
+			(ts.tv_nsec % NSEC_PER_MSEC) / USEC_PER_MSEC,	\
+			__func__, msg,					\
+			shared->hw_running ? "running" : "   idle",	\
+			gc_readl(priv, REG_GCISCR),			\
+			gc_readl(priv, REG_GCRBBR),			\
+			gc_readl(priv, REG_GCRBLR),			\
+			(gc_readl(priv, REG_GCRBEXHR) - base) / 4,	\
+			(gc_readl(priv, REG_GCRBHR) - base) / 4,	\
+			(gc_readl(priv, REG_GCRBTR) - base) / 4);	\
+	} while (0)
+
+static void
+pxa3xx_gcu_reset(struct pxa3xx_gcu_priv *priv)
+{
+	QDUMP("RESET");
+
+	/* disable interrupts */
+	gc_writel(priv, REG_GCIECR, 0);
+
+	/* reset hardware */
+	gc_writel(priv, REG_GCCR, GCCR_ABORT);
+	gc_writel(priv, REG_GCCR, 0);
+
+	memset(priv->shared, 0, SHARED_SIZE);
+	priv->shared->buffer_phys = priv->shared_phys;
+	priv->shared->magic = PXA3XX_GCU_SHARED_MAGIC;
+
+	ktime_get_ts64(&priv->base_time);
+
+	/* set up the ring buffer pointers */
+	gc_writel(priv, REG_GCRBLR, 0);
+	gc_writel(priv, REG_GCRBBR, priv->shared_phys);
+	gc_writel(priv, REG_GCRBTR, priv->shared_phys);
+
+	/* enable all IRQs except EOB */
+	gc_writel(priv, REG_GCIECR, IE_ALL & ~IE_EOB);
+}
+
+static void
+dump_whole_state(struct pxa3xx_gcu_priv *priv)
+{
+	struct pxa3xx_gcu_shared *sh = priv->shared;
+	u32 base = gc_readl(priv, REG_GCRBBR);
+
+	QDUMP("DUMP");
+
+	printk(KERN_DEBUG "== PXA3XX-GCU DUMP ==\n"
+		"%s, STATUS 0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, T %5ld\n",
+		sh->hw_running ? "running" : "idle   ",
+		gc_readl(priv, REG_GCISCR),
+		gc_readl(priv, REG_GCRBBR),
+		gc_readl(priv, REG_GCRBLR),
+		(gc_readl(priv, REG_GCRBEXHR) - base) / 4,
+		(gc_readl(priv, REG_GCRBHR) - base) / 4,
+		(gc_readl(priv, REG_GCRBTR) - base) / 4);
+}
+
+static void
+flush_running(struct pxa3xx_gcu_priv *priv)
+{
+	struct pxa3xx_gcu_batch *running = priv->running;
+	struct pxa3xx_gcu_batch *next;
+
+	while (running) {
+		next = running->next;
+		running->next = priv->free;
+		priv->free = running;
+		running = next;
+	}
+
+	priv->running = NULL;
+}
+
+static void
+run_ready(struct pxa3xx_gcu_priv *priv)
+{
+	unsigned int num = 0;
+	struct pxa3xx_gcu_shared *shared = priv->shared;
+	struct pxa3xx_gcu_batch	*ready = priv->ready;
+
+	QDUMP("Start");
+
+	BUG_ON(!ready);
+
+	shared->buffer[num++] = 0x05000000;
+
+	while (ready) {
+		shared->buffer[num++] = 0x00000001;
+		shared->buffer[num++] = ready->phys;
+		ready = ready->next;
+	}
+
+	shared->buffer[num++] = 0x05000000;
+	priv->running = priv->ready;
+	priv->ready = priv->ready_last = NULL;
+	gc_writel(priv, REG_GCRBLR, 0);
+	shared->hw_running = 1;
+
+	/* ring base address */
+	gc_writel(priv, REG_GCRBBR, shared->buffer_phys);
+
+	/* ring tail address */
+	gc_writel(priv, REG_GCRBTR, shared->buffer_phys + num * 4);
+
+	/* ring length */
+	gc_writel(priv, REG_GCRBLR, ((num + 63) & ~63) * 4);
+}
+
+static irqreturn_t
+pxa3xx_gcu_handle_irq(int irq, void *ctx)
+{
+	struct pxa3xx_gcu_priv *priv = ctx;
+	struct pxa3xx_gcu_shared *shared = priv->shared;
+	u32 status = gc_readl(priv, REG_GCISCR) & IE_ALL;
+
+	QDUMP("-Interrupt");
+
+	if (!status)
+		return IRQ_NONE;
+
+	spin_lock(&priv->spinlock);
+	shared->num_interrupts++;
+
+	if (status & IE_EEOB) {
+		QDUMP(" [EEOB]");
+
+		flush_running(priv);
+		wake_up_all(&priv->wait_free);
+
+		if (priv->ready) {
+			run_ready(priv);
+		} else {
+			/* There is no more data prepared by the userspace.
+			 * Set hw_running = 0 and wait for the next userspace
+			 * kick-off */
+			shared->num_idle++;
+			shared->hw_running = 0;
+
+			QDUMP(" '-> Idle.");
+
+			/* set ring buffer length to zero */
+			gc_writel(priv, REG_GCRBLR, 0);
+
+			wake_up_all(&priv->wait_idle);
+		}
+
+		shared->num_done++;
+	} else {
+		QERROR(" [???]");
+		dump_whole_state(priv);
+	}
+
+	/* Clear the interrupt */
+	gc_writel(priv, REG_GCISCR, status);
+	spin_unlock(&priv->spinlock);
+
+	return IRQ_HANDLED;
+}
+
+static int
+pxa3xx_gcu_wait_idle(struct pxa3xx_gcu_priv *priv)
+{
+	int ret = 0;
+
+	QDUMP("Waiting for idle...");
+
+	/* Does not need to be atomic. There's a lock in user space,
+	 * but anyhow, this is just for statistics. */
+	priv->shared->num_wait_idle++;
+
+	while (priv->shared->hw_running) {
+		int num = priv->shared->num_interrupts;
+		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
+
+		ret = wait_event_interruptible_timeout(priv->wait_idle,
+					!priv->shared->hw_running, HZ*4);
+
+		if (ret != 0)
+			break;
+
+		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr &&
+		    priv->shared->num_interrupts == num) {
+			QERROR("TIMEOUT");
+			ret = -ETIMEDOUT;
+			break;
+		}
+	}
+
+	QDUMP("done");
+
+	return ret;
+}
+
+static int
+pxa3xx_gcu_wait_free(struct pxa3xx_gcu_priv *priv)
+{
+	int ret = 0;
+
+	QDUMP("Waiting for free...");
+
+	/* Does not need to be atomic. There's a lock in user space,
+	 * but anyhow, this is just for statistics. */
+	priv->shared->num_wait_free++;
+
+	while (!priv->free) {
+		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
+
+		ret = wait_event_interruptible_timeout(priv->wait_free,
+						       priv->free, HZ*4);
+
+		if (ret < 0)
+			break;
+
+		if (ret > 0)
+			continue;
+
+		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr) {
+			QERROR("TIMEOUT");
+			ret = -ETIMEDOUT;
+			break;
+		}
+	}
+
+	QDUMP("done");
+
+	return ret;
+}
+
+/* Misc device layer */
+
+static inline struct pxa3xx_gcu_priv *to_pxa3xx_gcu_priv(struct file *file)
+{
+	struct miscdevice *dev = file->private_data;
+	return container_of(dev, struct pxa3xx_gcu_priv, misc_dev);
+}
+
+/*
+ * provide an empty .open callback, so the core sets file->private_data
+ * for us.
+ */
+static int pxa3xx_gcu_open(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+static ssize_t
+pxa3xx_gcu_write(struct file *file, const char *buff,
+		 size_t count, loff_t *offp)
+{
+	int ret;
+	unsigned long flags;
+	struct pxa3xx_gcu_batch	*buffer;
+	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
+
+	int words = count / 4;
+
+	/* Does not need to be atomic. There's a lock in user space,
+	 * but anyhow, this is just for statistics. */
+	priv->shared->num_writes++;
+	priv->shared->num_words += words;
+
+	/* Last word reserved for batch buffer end command */
+	if (words >= PXA3XX_GCU_BATCH_WORDS)
+		return -E2BIG;
+
+	/* Wait for a free buffer */
+	if (!priv->free) {
+		ret = pxa3xx_gcu_wait_free(priv);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * Get buffer from free list
+	 */
+	spin_lock_irqsave(&priv->spinlock, flags);
+	buffer = priv->free;
+	priv->free = buffer->next;
+	spin_unlock_irqrestore(&priv->spinlock, flags);
+
+
+	/* Copy data from user into buffer */
+	ret = copy_from_user(buffer->ptr, buff, words * 4);
+	if (ret) {
+		spin_lock_irqsave(&priv->spinlock, flags);
+		buffer->next = priv->free;
+		priv->free = buffer;
+		spin_unlock_irqrestore(&priv->spinlock, flags);
+		return -EFAULT;
+	}
+
+	buffer->length = words;
+
+	/* Append batch buffer end command */
+	buffer->ptr[words] = 0x01000000;
+
+	/*
+	 * Add buffer to ready list
+	 */
+	spin_lock_irqsave(&priv->spinlock, flags);
+
+	buffer->next = NULL;
+
+	if (priv->ready) {
+		BUG_ON(priv->ready_last == NULL);
+
+		priv->ready_last->next = buffer;
+	} else
+		priv->ready = buffer;
+
+	priv->ready_last = buffer;
+
+	if (!priv->shared->hw_running)
+		run_ready(priv);
+
+	spin_unlock_irqrestore(&priv->spinlock, flags);
+
+	return words * 4;
+}
+
+
+static long
+pxa3xx_gcu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	unsigned long flags;
+	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
+
+	switch (cmd) {
+	case PXA3XX_GCU_IOCTL_RESET:
+		spin_lock_irqsave(&priv->spinlock, flags);
+		pxa3xx_gcu_reset(priv);
+		spin_unlock_irqrestore(&priv->spinlock, flags);
+		return 0;
+
+	case PXA3XX_GCU_IOCTL_WAIT_IDLE:
+		return pxa3xx_gcu_wait_idle(priv);
+	}
+
+	return -ENOSYS;
+}
+
+static int
+pxa3xx_gcu_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	unsigned int size = vma->vm_end - vma->vm_start;
+	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
+
+	switch (vma->vm_pgoff) {
+	case 0:
+		/* hand out the shared data area */
+		if (size != SHARED_SIZE)
+			return -EINVAL;
+
+		return dma_mmap_coherent(NULL, vma,
+			priv->shared, priv->shared_phys, size);
+
+	case SHARED_SIZE >> PAGE_SHIFT:
+		/* hand out the MMIO base for direct register access
+		 * from userspace */
+		if (size != resource_size(priv->resource_mem))
+			return -EINVAL;
+
+		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+		return io_remap_pfn_range(vma, vma->vm_start,
+				priv->resource_mem->start >> PAGE_SHIFT,
+				size, vma->vm_page_prot);
+	}
+
+	return -EINVAL;
+}
+
+
+#ifdef PXA3XX_GCU_DEBUG_TIMER
+static struct timer_list pxa3xx_gcu_debug_timer;
+static struct pxa3xx_gcu_priv *debug_timer_priv;
+
+static void pxa3xx_gcu_debug_timedout(struct timer_list *unused)
+{
+	struct pxa3xx_gcu_priv *priv = debug_timer_priv;
+
+	QERROR("Timer DUMP");
+
+	mod_timer(&pxa3xx_gcu_debug_timer, jiffies + 5 * HZ);
+}
+
+static void pxa3xx_gcu_init_debug_timer(struct pxa3xx_gcu_priv *priv)
+{
+	/* init the timer structure */
+	debug_timer_priv = priv;
+	timer_setup(&pxa3xx_gcu_debug_timer, pxa3xx_gcu_debug_timedout, 0);
+	pxa3xx_gcu_debug_timedout(NULL);
+}
+#else
+static inline void pxa3xx_gcu_init_debug_timer(struct pxa3xx_gcu_priv *priv) {}
+#endif
+
+static int
+pxa3xx_gcu_add_buffer(struct device *dev,
+		      struct pxa3xx_gcu_priv *priv)
+{
+	struct pxa3xx_gcu_batch *buffer;
+
+	buffer = kzalloc(sizeof(struct pxa3xx_gcu_batch), GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	buffer->ptr = dma_alloc_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4,
+					 &buffer->phys, GFP_KERNEL);
+	if (!buffer->ptr) {
+		kfree(buffer);
+		return -ENOMEM;
+	}
+
+	buffer->next = priv->free;
+	priv->free = buffer;
+
+	return 0;
+}
+
+static void
+pxa3xx_gcu_free_buffers(struct device *dev,
+			struct pxa3xx_gcu_priv *priv)
+{
+	struct pxa3xx_gcu_batch *next, *buffer = priv->free;
+
+	while (buffer) {
+		next = buffer->next;
+
+		dma_free_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4,
+				  buffer->ptr, buffer->phys);
+
+		kfree(buffer);
+		buffer = next;
+	}
+
+	priv->free = NULL;
+}
+
+static const struct file_operations pxa3xx_gcu_miscdev_fops = {
+	.owner =		THIS_MODULE,
+	.open =			pxa3xx_gcu_open,
+	.write =		pxa3xx_gcu_write,
+	.unlocked_ioctl =	pxa3xx_gcu_ioctl,
+	.mmap =			pxa3xx_gcu_mmap,
+};
+
+static int pxa3xx_gcu_probe(struct platform_device *pdev)
+{
+	int i, ret, irq;
+	struct resource *r;
+	struct pxa3xx_gcu_priv *priv;
+	struct device *dev = &pdev->dev;
+
+	priv = devm_kzalloc(dev, sizeof(struct pxa3xx_gcu_priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	init_waitqueue_head(&priv->wait_idle);
+	init_waitqueue_head(&priv->wait_free);
+	spin_lock_init(&priv->spinlock);
+
+	/* we allocate the misc device structure as part of our own allocation,
+	 * so we can get a pointer to our priv structure later on with
+	 * container_of(). This isn't really necessary as we have a fixed minor
+	 * number anyway, but this is to avoid statics. */
+
+	priv->misc_dev.minor	= MISCDEV_MINOR,
+	priv->misc_dev.name	= DRV_NAME,
+	priv->misc_dev.fops	= &pxa3xx_gcu_miscdev_fops;
+
+	/* handle IO resources */
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->mmio_base = devm_ioremap_resource(dev, r);
+	if (IS_ERR(priv->mmio_base))
+		return PTR_ERR(priv->mmio_base);
+
+	/* enable the clock */
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "failed to get clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	/* request the IRQ */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "no IRQ defined: %d\n", irq);
+		return irq;
+	}
+
+	ret = devm_request_irq(dev, irq, pxa3xx_gcu_handle_irq,
+			       0, DRV_NAME, priv);
+	if (ret < 0) {
+		dev_err(dev, "request_irq failed\n");
+		return ret;
+	}
+
+	/* allocate dma memory */
+	priv->shared = dma_alloc_coherent(dev, SHARED_SIZE,
+					  &priv->shared_phys, GFP_KERNEL);
+	if (!priv->shared) {
+		dev_err(dev, "failed to allocate DMA memory\n");
+		return -ENOMEM;
+	}
+
+	/* register misc device */
+	ret = misc_register(&priv->misc_dev);
+	if (ret < 0) {
+		dev_err(dev, "misc_register() for minor %d failed\n",
+			MISCDEV_MINOR);
+		goto err_free_dma;
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable clock\n");
+		goto err_misc_deregister;
+	}
+
+	for (i = 0; i < 8; i++) {
+		ret = pxa3xx_gcu_add_buffer(dev, priv);
+		if (ret) {
+			pxa3xx_gcu_free_buffers(dev, priv);
+			dev_err(dev, "failed to allocate DMA memory\n");
+			goto err_disable_clk;
+		}
+	}
+
+	platform_set_drvdata(pdev, priv);
+	priv->resource_mem = r;
+	pxa3xx_gcu_reset(priv);
+	pxa3xx_gcu_init_debug_timer(priv);
+
+	dev_info(dev, "registered @0x%p, DMA 0x%p (%d bytes), IRQ %d\n",
+			(void *) r->start, (void *) priv->shared_phys,
+			SHARED_SIZE, irq);
+	return 0;
+
+err_disable_clk:
+	clk_disable_unprepare(priv->clk);
+
+err_misc_deregister:
+	misc_deregister(&priv->misc_dev);
+
+err_free_dma:
+	dma_free_coherent(dev, SHARED_SIZE,
+			  priv->shared, priv->shared_phys);
+
+	return ret;
+}
+
+static int pxa3xx_gcu_remove(struct platform_device *pdev)
+{
+	struct pxa3xx_gcu_priv *priv = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	pxa3xx_gcu_wait_idle(priv);
+	misc_deregister(&priv->misc_dev);
+	dma_free_coherent(dev, SHARED_SIZE, priv->shared, priv->shared_phys);
+	clk_disable_unprepare(priv->clk);
+	pxa3xx_gcu_free_buffers(dev, priv);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id pxa3xx_gcu_of_match[] = {
+	{ .compatible = "marvell,pxa300-gcu", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pxa3xx_gcu_of_match);
+#endif
+
+static struct platform_driver pxa3xx_gcu_driver = {
+	.probe	  = pxa3xx_gcu_probe,
+	.remove	 = pxa3xx_gcu_remove,
+	.driver	 = {
+		.name   = DRV_NAME,
+		.of_match_table = of_match_ptr(pxa3xx_gcu_of_match),
+	},
+};
+
+module_platform_driver(pxa3xx_gcu_driver);
+
+MODULE_DESCRIPTION("PXA3xx graphics controller unit driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(MISCDEV_MINOR);
+MODULE_AUTHOR("Janine Kropp <nin@directfb.org>, "
+		"Denis Oliver Kropp <dok@directfb.org>, "
+		"Daniel Mack <daniel@caiaq.de>");