xref: /openbmc/linux/drivers/video/fbdev/pxa3xx-gcu.c (revision 455f9726)
1 /*
2  *  pxa3xx-gcu.c - Linux kernel module for PXA3xx graphics controllers
3  *
4  *  This driver needs a DirectFB counterpart in user space, communication
5  *  is handled via mmap()ed memory areas and an ioctl.
6  *
7  *  Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
8  *  Copyright (c) 2009 Janine Kropp <nin@directfb.org>
9  *  Copyright (c) 2009 Denis Oliver Kropp <dok@directfb.org>
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or
14  *  (at your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  *  GNU General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License
22  *  along with this program; if not, write to the Free Software
23  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24  */
25 
26 /*
27  * WARNING: This controller is attached to System Bus 2 of the PXA which
28  * needs its arbiter to be enabled explicitly (CKENB & 1<<9).
29  * There is currently no way to do this from Linux, so you need to teach
30  * your bootloader for now.
31  */
32 
33 #include <linux/module.h>
34 #include <linux/platform_device.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/miscdevice.h>
37 #include <linux/interrupt.h>
38 #include <linux/spinlock.h>
39 #include <linux/uaccess.h>
40 #include <linux/ioctl.h>
41 #include <linux/delay.h>
42 #include <linux/sched.h>
43 #include <linux/slab.h>
44 #include <linux/clk.h>
45 #include <linux/fs.h>
46 #include <linux/io.h>
47 
48 #include "pxa3xx-gcu.h"
49 
50 #define DRV_NAME	"pxa3xx-gcu"
51 #define MISCDEV_MINOR	197
52 
53 #define REG_GCCR	0x00
54 #define GCCR_SYNC_CLR	(1 << 9)
55 #define GCCR_BP_RST	(1 << 8)
56 #define GCCR_ABORT	(1 << 6)
57 #define GCCR_STOP	(1 << 4)
58 
59 #define REG_GCISCR	0x04
60 #define REG_GCIECR	0x08
61 #define REG_GCRBBR	0x20
62 #define REG_GCRBLR	0x24
63 #define REG_GCRBHR	0x28
64 #define REG_GCRBTR	0x2C
65 #define REG_GCRBEXHR	0x30
66 
67 #define IE_EOB		(1 << 0)
68 #define IE_EEOB		(1 << 5)
69 #define IE_ALL		0xff
70 
71 #define SHARED_SIZE	PAGE_ALIGN(sizeof(struct pxa3xx_gcu_shared))
72 
73 /* #define PXA3XX_GCU_DEBUG */
74 /* #define PXA3XX_GCU_DEBUG_TIMER */
75 
76 #ifdef PXA3XX_GCU_DEBUG
77 #define QDUMP(msg)					\
78 	do {						\
79 		QPRINT(priv, KERN_DEBUG, msg);		\
80 	} while (0)
81 #else
82 #define QDUMP(msg)	do {} while (0)
83 #endif
84 
85 #define QERROR(msg)					\
86 	do {						\
87 		QPRINT(priv, KERN_ERR, msg);		\
88 	} while (0)
89 
90 struct pxa3xx_gcu_batch {
91 	struct pxa3xx_gcu_batch *next;
92 	u32			*ptr;
93 	dma_addr_t		 phys;
94 	unsigned long		 length;
95 };
96 
97 struct pxa3xx_gcu_priv {
98 	void __iomem		 *mmio_base;
99 	struct clk		 *clk;
100 	struct pxa3xx_gcu_shared *shared;
101 	dma_addr_t		  shared_phys;
102 	struct resource		 *resource_mem;
103 	struct miscdevice	  misc_dev;
104 	wait_queue_head_t	  wait_idle;
105 	wait_queue_head_t	  wait_free;
106 	spinlock_t		  spinlock;
107 	struct timeval 		  base_time;
108 
109 	struct pxa3xx_gcu_batch *free;
110 	struct pxa3xx_gcu_batch *ready;
111 	struct pxa3xx_gcu_batch *ready_last;
112 	struct pxa3xx_gcu_batch *running;
113 };
114 
115 static inline unsigned long
116 gc_readl(struct pxa3xx_gcu_priv *priv, unsigned int off)
117 {
118 	return __raw_readl(priv->mmio_base + off);
119 }
120 
121 static inline void
122 gc_writel(struct pxa3xx_gcu_priv *priv, unsigned int off, unsigned long val)
123 {
124 	__raw_writel(val, priv->mmio_base + off);
125 }
126 
127 #define QPRINT(priv, level, msg)					\
128 	do {								\
129 		struct timeval tv;					\
130 		struct pxa3xx_gcu_shared *shared = priv->shared;	\
131 		u32 base = gc_readl(priv, REG_GCRBBR);			\
132 									\
133 		do_gettimeofday(&tv);					\
134 									\
135 		printk(level "%ld.%03ld.%03ld - %-17s: %-21s (%s, "	\
136 			"STATUS "					\
137 			"0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, "	\
138 			"T %5ld)\n",					\
139 			tv.tv_sec - priv->base_time.tv_sec,		\
140 			tv.tv_usec / 1000, tv.tv_usec % 1000,		\
141 			__func__, msg,					\
142 			shared->hw_running ? "running" : "   idle",	\
143 			gc_readl(priv, REG_GCISCR),			\
144 			gc_readl(priv, REG_GCRBBR),			\
145 			gc_readl(priv, REG_GCRBLR),			\
146 			(gc_readl(priv, REG_GCRBEXHR) - base) / 4,	\
147 			(gc_readl(priv, REG_GCRBHR) - base) / 4,	\
148 			(gc_readl(priv, REG_GCRBTR) - base) / 4);	\
149 	} while (0)
150 
151 static void
152 pxa3xx_gcu_reset(struct pxa3xx_gcu_priv *priv)
153 {
154 	QDUMP("RESET");
155 
156 	/* disable interrupts */
157 	gc_writel(priv, REG_GCIECR, 0);
158 
159 	/* reset hardware */
160 	gc_writel(priv, REG_GCCR, GCCR_ABORT);
161 	gc_writel(priv, REG_GCCR, 0);
162 
163 	memset(priv->shared, 0, SHARED_SIZE);
164 	priv->shared->buffer_phys = priv->shared_phys;
165 	priv->shared->magic = PXA3XX_GCU_SHARED_MAGIC;
166 
167 	do_gettimeofday(&priv->base_time);
168 
169 	/* set up the ring buffer pointers */
170 	gc_writel(priv, REG_GCRBLR, 0);
171 	gc_writel(priv, REG_GCRBBR, priv->shared_phys);
172 	gc_writel(priv, REG_GCRBTR, priv->shared_phys);
173 
174 	/* enable all IRQs except EOB */
175 	gc_writel(priv, REG_GCIECR, IE_ALL & ~IE_EOB);
176 }
177 
178 static void
179 dump_whole_state(struct pxa3xx_gcu_priv *priv)
180 {
181 	struct pxa3xx_gcu_shared *sh = priv->shared;
182 	u32 base = gc_readl(priv, REG_GCRBBR);
183 
184 	QDUMP("DUMP");
185 
186 	printk(KERN_DEBUG "== PXA3XX-GCU DUMP ==\n"
187 		"%s, STATUS 0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, T %5ld\n",
188 		sh->hw_running ? "running" : "idle   ",
189 		gc_readl(priv, REG_GCISCR),
190 		gc_readl(priv, REG_GCRBBR),
191 		gc_readl(priv, REG_GCRBLR),
192 		(gc_readl(priv, REG_GCRBEXHR) - base) / 4,
193 		(gc_readl(priv, REG_GCRBHR) - base) / 4,
194 		(gc_readl(priv, REG_GCRBTR) - base) / 4);
195 }
196 
197 static void
198 flush_running(struct pxa3xx_gcu_priv *priv)
199 {
200 	struct pxa3xx_gcu_batch *running = priv->running;
201 	struct pxa3xx_gcu_batch *next;
202 
203 	while (running) {
204 		next = running->next;
205 		running->next = priv->free;
206 		priv->free = running;
207 		running = next;
208 	}
209 
210 	priv->running = NULL;
211 }
212 
213 static void
214 run_ready(struct pxa3xx_gcu_priv *priv)
215 {
216 	unsigned int num = 0;
217 	struct pxa3xx_gcu_shared *shared = priv->shared;
218 	struct pxa3xx_gcu_batch	*ready = priv->ready;
219 
220 	QDUMP("Start");
221 
222 	BUG_ON(!ready);
223 
224 	shared->buffer[num++] = 0x05000000;
225 
226 	while (ready) {
227 		shared->buffer[num++] = 0x00000001;
228 		shared->buffer[num++] = ready->phys;
229 		ready = ready->next;
230 	}
231 
232 	shared->buffer[num++] = 0x05000000;
233 	priv->running = priv->ready;
234 	priv->ready = priv->ready_last = NULL;
235 	gc_writel(priv, REG_GCRBLR, 0);
236 	shared->hw_running = 1;
237 
238 	/* ring base address */
239 	gc_writel(priv, REG_GCRBBR, shared->buffer_phys);
240 
241 	/* ring tail address */
242 	gc_writel(priv, REG_GCRBTR, shared->buffer_phys + num * 4);
243 
244 	/* ring length */
245 	gc_writel(priv, REG_GCRBLR, ((num + 63) & ~63) * 4);
246 }
247 
248 static irqreturn_t
249 pxa3xx_gcu_handle_irq(int irq, void *ctx)
250 {
251 	struct pxa3xx_gcu_priv *priv = ctx;
252 	struct pxa3xx_gcu_shared *shared = priv->shared;
253 	u32 status = gc_readl(priv, REG_GCISCR) & IE_ALL;
254 
255 	QDUMP("-Interrupt");
256 
257 	if (!status)
258 		return IRQ_NONE;
259 
260 	spin_lock(&priv->spinlock);
261 	shared->num_interrupts++;
262 
263 	if (status & IE_EEOB) {
264 		QDUMP(" [EEOB]");
265 
266 		flush_running(priv);
267 		wake_up_all(&priv->wait_free);
268 
269 		if (priv->ready) {
270 			run_ready(priv);
271 		} else {
272 			/* There is no more data prepared by the userspace.
273 			 * Set hw_running = 0 and wait for the next userspace
274 			 * kick-off */
275 			shared->num_idle++;
276 			shared->hw_running = 0;
277 
278 			QDUMP(" '-> Idle.");
279 
280 			/* set ring buffer length to zero */
281 			gc_writel(priv, REG_GCRBLR, 0);
282 
283 			wake_up_all(&priv->wait_idle);
284 		}
285 
286 		shared->num_done++;
287 	} else {
288 		QERROR(" [???]");
289 		dump_whole_state(priv);
290 	}
291 
292 	/* Clear the interrupt */
293 	gc_writel(priv, REG_GCISCR, status);
294 	spin_unlock(&priv->spinlock);
295 
296 	return IRQ_HANDLED;
297 }
298 
299 static int
300 pxa3xx_gcu_wait_idle(struct pxa3xx_gcu_priv *priv)
301 {
302 	int ret = 0;
303 
304 	QDUMP("Waiting for idle...");
305 
306 	/* Does not need to be atomic. There's a lock in user space,
307 	 * but anyhow, this is just for statistics. */
308 	priv->shared->num_wait_idle++;
309 
310 	while (priv->shared->hw_running) {
311 		int num = priv->shared->num_interrupts;
312 		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
313 
314 		ret = wait_event_interruptible_timeout(priv->wait_idle,
315 					!priv->shared->hw_running, HZ*4);
316 
317 		if (ret != 0)
318 			break;
319 
320 		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr &&
321 		    priv->shared->num_interrupts == num) {
322 			QERROR("TIMEOUT");
323 			ret = -ETIMEDOUT;
324 			break;
325 		}
326 	}
327 
328 	QDUMP("done");
329 
330 	return ret;
331 }
332 
333 static int
334 pxa3xx_gcu_wait_free(struct pxa3xx_gcu_priv *priv)
335 {
336 	int ret = 0;
337 
338 	QDUMP("Waiting for free...");
339 
340 	/* Does not need to be atomic. There's a lock in user space,
341 	 * but anyhow, this is just for statistics. */
342 	priv->shared->num_wait_free++;
343 
344 	while (!priv->free) {
345 		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
346 
347 		ret = wait_event_interruptible_timeout(priv->wait_free,
348 						       priv->free, HZ*4);
349 
350 		if (ret < 0)
351 			break;
352 
353 		if (ret > 0)
354 			continue;
355 
356 		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr) {
357 			QERROR("TIMEOUT");
358 			ret = -ETIMEDOUT;
359 			break;
360 		}
361 	}
362 
363 	QDUMP("done");
364 
365 	return ret;
366 }
367 
368 /* Misc device layer */
369 
370 static inline struct pxa3xx_gcu_priv *to_pxa3xx_gcu_priv(struct file *file)
371 {
372 	struct miscdevice *dev = file->private_data;
373 	return container_of(dev, struct pxa3xx_gcu_priv, misc_dev);
374 }
375 
376 /*
377  * provide an empty .open callback, so the core sets file->private_data
378  * for us.
379  */
380 static int pxa3xx_gcu_open(struct inode *inode, struct file *file)
381 {
382 	return 0;
383 }
384 
385 static ssize_t
386 pxa3xx_gcu_write(struct file *file, const char *buff,
387 		 size_t count, loff_t *offp)
388 {
389 	int ret;
390 	unsigned long flags;
391 	struct pxa3xx_gcu_batch	*buffer;
392 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
393 
394 	int words = count / 4;
395 
396 	/* Does not need to be atomic. There's a lock in user space,
397 	 * but anyhow, this is just for statistics. */
398 	priv->shared->num_writes++;
399 	priv->shared->num_words += words;
400 
401 	/* Last word reserved for batch buffer end command */
402 	if (words >= PXA3XX_GCU_BATCH_WORDS)
403 		return -E2BIG;
404 
405 	/* Wait for a free buffer */
406 	if (!priv->free) {
407 		ret = pxa3xx_gcu_wait_free(priv);
408 		if (ret < 0)
409 			return ret;
410 	}
411 
412 	/*
413 	 * Get buffer from free list
414 	 */
415 	spin_lock_irqsave(&priv->spinlock, flags);
416 	buffer = priv->free;
417 	priv->free = buffer->next;
418 	spin_unlock_irqrestore(&priv->spinlock, flags);
419 
420 
421 	/* Copy data from user into buffer */
422 	ret = copy_from_user(buffer->ptr, buff, words * 4);
423 	if (ret) {
424 		spin_lock_irqsave(&priv->spinlock, flags);
425 		buffer->next = priv->free;
426 		priv->free = buffer;
427 		spin_unlock_irqrestore(&priv->spinlock, flags);
428 		return -EFAULT;
429 	}
430 
431 	buffer->length = words;
432 
433 	/* Append batch buffer end command */
434 	buffer->ptr[words] = 0x01000000;
435 
436 	/*
437 	 * Add buffer to ready list
438 	 */
439 	spin_lock_irqsave(&priv->spinlock, flags);
440 
441 	buffer->next = NULL;
442 
443 	if (priv->ready) {
444 		BUG_ON(priv->ready_last == NULL);
445 
446 		priv->ready_last->next = buffer;
447 	} else
448 		priv->ready = buffer;
449 
450 	priv->ready_last = buffer;
451 
452 	if (!priv->shared->hw_running)
453 		run_ready(priv);
454 
455 	spin_unlock_irqrestore(&priv->spinlock, flags);
456 
457 	return words * 4;
458 }
459 
460 
461 static long
462 pxa3xx_gcu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
463 {
464 	unsigned long flags;
465 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
466 
467 	switch (cmd) {
468 	case PXA3XX_GCU_IOCTL_RESET:
469 		spin_lock_irqsave(&priv->spinlock, flags);
470 		pxa3xx_gcu_reset(priv);
471 		spin_unlock_irqrestore(&priv->spinlock, flags);
472 		return 0;
473 
474 	case PXA3XX_GCU_IOCTL_WAIT_IDLE:
475 		return pxa3xx_gcu_wait_idle(priv);
476 	}
477 
478 	return -ENOSYS;
479 }
480 
481 static int
482 pxa3xx_gcu_mmap(struct file *file, struct vm_area_struct *vma)
483 {
484 	unsigned int size = vma->vm_end - vma->vm_start;
485 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
486 
487 	switch (vma->vm_pgoff) {
488 	case 0:
489 		/* hand out the shared data area */
490 		if (size != SHARED_SIZE)
491 			return -EINVAL;
492 
493 		return dma_mmap_coherent(NULL, vma,
494 			priv->shared, priv->shared_phys, size);
495 
496 	case SHARED_SIZE >> PAGE_SHIFT:
497 		/* hand out the MMIO base for direct register access
498 		 * from userspace */
499 		if (size != resource_size(priv->resource_mem))
500 			return -EINVAL;
501 
502 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
503 
504 		return io_remap_pfn_range(vma, vma->vm_start,
505 				priv->resource_mem->start >> PAGE_SHIFT,
506 				size, vma->vm_page_prot);
507 	}
508 
509 	return -EINVAL;
510 }
511 
512 
513 #ifdef PXA3XX_GCU_DEBUG_TIMER
514 static struct timer_list pxa3xx_gcu_debug_timer;
515 
516 static void pxa3xx_gcu_debug_timedout(unsigned long ptr)
517 {
518 	struct pxa3xx_gcu_priv *priv = (struct pxa3xx_gcu_priv *) ptr;
519 
520 	QERROR("Timer DUMP");
521 
522 	/* init the timer structure */
523 	init_timer(&pxa3xx_gcu_debug_timer);
524 	pxa3xx_gcu_debug_timer.function = pxa3xx_gcu_debug_timedout;
525 	pxa3xx_gcu_debug_timer.data = ptr;
526 	pxa3xx_gcu_debug_timer.expires = jiffies + 5*HZ; /* one second */
527 
528 	add_timer(&pxa3xx_gcu_debug_timer);
529 }
530 
531 static void pxa3xx_gcu_init_debug_timer(void)
532 {
533 	pxa3xx_gcu_debug_timedout((unsigned long) &pxa3xx_gcu_debug_timer);
534 }
535 #else
536 static inline void pxa3xx_gcu_init_debug_timer(void) {}
537 #endif
538 
539 static int
540 pxa3xx_gcu_add_buffer(struct device *dev,
541 		      struct pxa3xx_gcu_priv *priv)
542 {
543 	struct pxa3xx_gcu_batch *buffer;
544 
545 	buffer = kzalloc(sizeof(struct pxa3xx_gcu_batch), GFP_KERNEL);
546 	if (!buffer)
547 		return -ENOMEM;
548 
549 	buffer->ptr = dma_alloc_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4,
550 					 &buffer->phys, GFP_KERNEL);
551 	if (!buffer->ptr) {
552 		kfree(buffer);
553 		return -ENOMEM;
554 	}
555 
556 	buffer->next = priv->free;
557 	priv->free = buffer;
558 
559 	return 0;
560 }
561 
562 static void
563 pxa3xx_gcu_free_buffers(struct device *dev,
564 			struct pxa3xx_gcu_priv *priv)
565 {
566 	struct pxa3xx_gcu_batch *next, *buffer = priv->free;
567 
568 	while (buffer) {
569 		next = buffer->next;
570 
571 		dma_free_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4,
572 				  buffer->ptr, buffer->phys);
573 
574 		kfree(buffer);
575 		buffer = next;
576 	}
577 
578 	priv->free = NULL;
579 }
580 
581 static const struct file_operations pxa3xx_gcu_miscdev_fops = {
582 	.owner =		THIS_MODULE,
583 	.open =			pxa3xx_gcu_open,
584 	.write =		pxa3xx_gcu_write,
585 	.unlocked_ioctl =	pxa3xx_gcu_ioctl,
586 	.mmap =			pxa3xx_gcu_mmap,
587 };
588 
589 static int pxa3xx_gcu_probe(struct platform_device *pdev)
590 {
591 	int i, ret, irq;
592 	struct resource *r;
593 	struct pxa3xx_gcu_priv *priv;
594 	struct device *dev = &pdev->dev;
595 
596 	priv = devm_kzalloc(dev, sizeof(struct pxa3xx_gcu_priv), GFP_KERNEL);
597 	if (!priv)
598 		return -ENOMEM;
599 
600 	init_waitqueue_head(&priv->wait_idle);
601 	init_waitqueue_head(&priv->wait_free);
602 	spin_lock_init(&priv->spinlock);
603 
604 	/* we allocate the misc device structure as part of our own allocation,
605 	 * so we can get a pointer to our priv structure later on with
606 	 * container_of(). This isn't really necessary as we have a fixed minor
607 	 * number anyway, but this is to avoid statics. */
608 
609 	priv->misc_dev.minor	= MISCDEV_MINOR,
610 	priv->misc_dev.name	= DRV_NAME,
611 	priv->misc_dev.fops	= &pxa3xx_gcu_miscdev_fops;
612 
613 	/* handle IO resources */
614 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
615 	priv->mmio_base = devm_ioremap_resource(dev, r);
616 	if (IS_ERR(priv->mmio_base))
617 		return PTR_ERR(priv->mmio_base);
618 
619 	/* enable the clock */
620 	priv->clk = devm_clk_get(dev, NULL);
621 	if (IS_ERR(priv->clk)) {
622 		dev_err(dev, "failed to get clock\n");
623 		return PTR_ERR(priv->clk);
624 	}
625 
626 	/* request the IRQ */
627 	irq = platform_get_irq(pdev, 0);
628 	if (irq < 0) {
629 		dev_err(dev, "no IRQ defined\n");
630 		return -ENODEV;
631 	}
632 
633 	ret = devm_request_irq(dev, irq, pxa3xx_gcu_handle_irq,
634 			       0, DRV_NAME, priv);
635 	if (ret < 0) {
636 		dev_err(dev, "request_irq failed\n");
637 		return ret;
638 	}
639 
640 	/* allocate dma memory */
641 	priv->shared = dma_alloc_coherent(dev, SHARED_SIZE,
642 					  &priv->shared_phys, GFP_KERNEL);
643 	if (!priv->shared) {
644 		dev_err(dev, "failed to allocate DMA memory\n");
645 		return -ENOMEM;
646 	}
647 
648 	/* register misc device */
649 	ret = misc_register(&priv->misc_dev);
650 	if (ret < 0) {
651 		dev_err(dev, "misc_register() for minor %d failed\n",
652 			MISCDEV_MINOR);
653 		goto err_free_dma;
654 	}
655 
656 	ret = clk_enable(priv->clk);
657 	if (ret < 0) {
658 		dev_err(dev, "failed to enable clock\n");
659 		goto err_misc_deregister;
660 	}
661 
662 	for (i = 0; i < 8; i++) {
663 		ret = pxa3xx_gcu_add_buffer(dev, priv);
664 		if (ret) {
665 			dev_err(dev, "failed to allocate DMA memory\n");
666 			goto err_disable_clk;
667 		}
668 	}
669 
670 	platform_set_drvdata(pdev, priv);
671 	priv->resource_mem = r;
672 	pxa3xx_gcu_reset(priv);
673 	pxa3xx_gcu_init_debug_timer();
674 
675 	dev_info(dev, "registered @0x%p, DMA 0x%p (%d bytes), IRQ %d\n",
676 			(void *) r->start, (void *) priv->shared_phys,
677 			SHARED_SIZE, irq);
678 	return 0;
679 
680 err_free_dma:
681 	dma_free_coherent(dev, SHARED_SIZE,
682 			priv->shared, priv->shared_phys);
683 
684 err_misc_deregister:
685 	misc_deregister(&priv->misc_dev);
686 
687 err_disable_clk:
688 	clk_disable(priv->clk);
689 
690 	return ret;
691 }
692 
693 static int pxa3xx_gcu_remove(struct platform_device *pdev)
694 {
695 	struct pxa3xx_gcu_priv *priv = platform_get_drvdata(pdev);
696 	struct device *dev = &pdev->dev;
697 
698 	pxa3xx_gcu_wait_idle(priv);
699 	misc_deregister(&priv->misc_dev);
700 	dma_free_coherent(dev, SHARED_SIZE, priv->shared, priv->shared_phys);
701 	pxa3xx_gcu_free_buffers(dev, priv);
702 
703 	return 0;
704 }
705 
706 static struct platform_driver pxa3xx_gcu_driver = {
707 	.probe	  = pxa3xx_gcu_probe,
708 	.remove	 = pxa3xx_gcu_remove,
709 	.driver	 = {
710 		.owner  = THIS_MODULE,
711 		.name   = DRV_NAME,
712 	},
713 };
714 
715 module_platform_driver(pxa3xx_gcu_driver);
716 
717 MODULE_DESCRIPTION("PXA3xx graphics controller unit driver");
718 MODULE_LICENSE("GPL");
719 MODULE_ALIAS_MISCDEV(MISCDEV_MINOR);
720 MODULE_AUTHOR("Janine Kropp <nin@directfb.org>, "
721 		"Denis Oliver Kropp <dok@directfb.org>, "
722 		"Daniel Mack <daniel@caiaq.de>");
723