xref: /openbmc/linux/drivers/video/fbdev/pxa3xx-gcu.c (revision 82e6fdd6)
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 timespec64	  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 timespec64 ts;					\
130 		struct pxa3xx_gcu_shared *shared = priv->shared;	\
131 		u32 base = gc_readl(priv, REG_GCRBBR);			\
132 									\
133 		ktime_get_ts64(&ts);					\
134 		ts = timespec64_sub(ts, priv->base_time);		\
135 									\
136 		printk(level "%lld.%03ld.%03ld - %-17s: %-21s (%s, "	\
137 			"STATUS "					\
138 			"0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, "	\
139 			"T %5ld)\n",					\
140 			(s64)(ts.tv_sec),				\
141 			ts.tv_nsec / NSEC_PER_MSEC,			\
142 			(ts.tv_nsec % NSEC_PER_MSEC) / USEC_PER_MSEC,	\
143 			__func__, msg,					\
144 			shared->hw_running ? "running" : "   idle",	\
145 			gc_readl(priv, REG_GCISCR),			\
146 			gc_readl(priv, REG_GCRBBR),			\
147 			gc_readl(priv, REG_GCRBLR),			\
148 			(gc_readl(priv, REG_GCRBEXHR) - base) / 4,	\
149 			(gc_readl(priv, REG_GCRBHR) - base) / 4,	\
150 			(gc_readl(priv, REG_GCRBTR) - base) / 4);	\
151 	} while (0)
152 
153 static void
154 pxa3xx_gcu_reset(struct pxa3xx_gcu_priv *priv)
155 {
156 	QDUMP("RESET");
157 
158 	/* disable interrupts */
159 	gc_writel(priv, REG_GCIECR, 0);
160 
161 	/* reset hardware */
162 	gc_writel(priv, REG_GCCR, GCCR_ABORT);
163 	gc_writel(priv, REG_GCCR, 0);
164 
165 	memset(priv->shared, 0, SHARED_SIZE);
166 	priv->shared->buffer_phys = priv->shared_phys;
167 	priv->shared->magic = PXA3XX_GCU_SHARED_MAGIC;
168 
169 	ktime_get_ts64(&priv->base_time);
170 
171 	/* set up the ring buffer pointers */
172 	gc_writel(priv, REG_GCRBLR, 0);
173 	gc_writel(priv, REG_GCRBBR, priv->shared_phys);
174 	gc_writel(priv, REG_GCRBTR, priv->shared_phys);
175 
176 	/* enable all IRQs except EOB */
177 	gc_writel(priv, REG_GCIECR, IE_ALL & ~IE_EOB);
178 }
179 
180 static void
181 dump_whole_state(struct pxa3xx_gcu_priv *priv)
182 {
183 	struct pxa3xx_gcu_shared *sh = priv->shared;
184 	u32 base = gc_readl(priv, REG_GCRBBR);
185 
186 	QDUMP("DUMP");
187 
188 	printk(KERN_DEBUG "== PXA3XX-GCU DUMP ==\n"
189 		"%s, STATUS 0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, T %5ld\n",
190 		sh->hw_running ? "running" : "idle   ",
191 		gc_readl(priv, REG_GCISCR),
192 		gc_readl(priv, REG_GCRBBR),
193 		gc_readl(priv, REG_GCRBLR),
194 		(gc_readl(priv, REG_GCRBEXHR) - base) / 4,
195 		(gc_readl(priv, REG_GCRBHR) - base) / 4,
196 		(gc_readl(priv, REG_GCRBTR) - base) / 4);
197 }
198 
199 static void
200 flush_running(struct pxa3xx_gcu_priv *priv)
201 {
202 	struct pxa3xx_gcu_batch *running = priv->running;
203 	struct pxa3xx_gcu_batch *next;
204 
205 	while (running) {
206 		next = running->next;
207 		running->next = priv->free;
208 		priv->free = running;
209 		running = next;
210 	}
211 
212 	priv->running = NULL;
213 }
214 
215 static void
216 run_ready(struct pxa3xx_gcu_priv *priv)
217 {
218 	unsigned int num = 0;
219 	struct pxa3xx_gcu_shared *shared = priv->shared;
220 	struct pxa3xx_gcu_batch	*ready = priv->ready;
221 
222 	QDUMP("Start");
223 
224 	BUG_ON(!ready);
225 
226 	shared->buffer[num++] = 0x05000000;
227 
228 	while (ready) {
229 		shared->buffer[num++] = 0x00000001;
230 		shared->buffer[num++] = ready->phys;
231 		ready = ready->next;
232 	}
233 
234 	shared->buffer[num++] = 0x05000000;
235 	priv->running = priv->ready;
236 	priv->ready = priv->ready_last = NULL;
237 	gc_writel(priv, REG_GCRBLR, 0);
238 	shared->hw_running = 1;
239 
240 	/* ring base address */
241 	gc_writel(priv, REG_GCRBBR, shared->buffer_phys);
242 
243 	/* ring tail address */
244 	gc_writel(priv, REG_GCRBTR, shared->buffer_phys + num * 4);
245 
246 	/* ring length */
247 	gc_writel(priv, REG_GCRBLR, ((num + 63) & ~63) * 4);
248 }
249 
250 static irqreturn_t
251 pxa3xx_gcu_handle_irq(int irq, void *ctx)
252 {
253 	struct pxa3xx_gcu_priv *priv = ctx;
254 	struct pxa3xx_gcu_shared *shared = priv->shared;
255 	u32 status = gc_readl(priv, REG_GCISCR) & IE_ALL;
256 
257 	QDUMP("-Interrupt");
258 
259 	if (!status)
260 		return IRQ_NONE;
261 
262 	spin_lock(&priv->spinlock);
263 	shared->num_interrupts++;
264 
265 	if (status & IE_EEOB) {
266 		QDUMP(" [EEOB]");
267 
268 		flush_running(priv);
269 		wake_up_all(&priv->wait_free);
270 
271 		if (priv->ready) {
272 			run_ready(priv);
273 		} else {
274 			/* There is no more data prepared by the userspace.
275 			 * Set hw_running = 0 and wait for the next userspace
276 			 * kick-off */
277 			shared->num_idle++;
278 			shared->hw_running = 0;
279 
280 			QDUMP(" '-> Idle.");
281 
282 			/* set ring buffer length to zero */
283 			gc_writel(priv, REG_GCRBLR, 0);
284 
285 			wake_up_all(&priv->wait_idle);
286 		}
287 
288 		shared->num_done++;
289 	} else {
290 		QERROR(" [???]");
291 		dump_whole_state(priv);
292 	}
293 
294 	/* Clear the interrupt */
295 	gc_writel(priv, REG_GCISCR, status);
296 	spin_unlock(&priv->spinlock);
297 
298 	return IRQ_HANDLED;
299 }
300 
301 static int
302 pxa3xx_gcu_wait_idle(struct pxa3xx_gcu_priv *priv)
303 {
304 	int ret = 0;
305 
306 	QDUMP("Waiting for idle...");
307 
308 	/* Does not need to be atomic. There's a lock in user space,
309 	 * but anyhow, this is just for statistics. */
310 	priv->shared->num_wait_idle++;
311 
312 	while (priv->shared->hw_running) {
313 		int num = priv->shared->num_interrupts;
314 		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
315 
316 		ret = wait_event_interruptible_timeout(priv->wait_idle,
317 					!priv->shared->hw_running, HZ*4);
318 
319 		if (ret != 0)
320 			break;
321 
322 		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr &&
323 		    priv->shared->num_interrupts == num) {
324 			QERROR("TIMEOUT");
325 			ret = -ETIMEDOUT;
326 			break;
327 		}
328 	}
329 
330 	QDUMP("done");
331 
332 	return ret;
333 }
334 
335 static int
336 pxa3xx_gcu_wait_free(struct pxa3xx_gcu_priv *priv)
337 {
338 	int ret = 0;
339 
340 	QDUMP("Waiting for free...");
341 
342 	/* Does not need to be atomic. There's a lock in user space,
343 	 * but anyhow, this is just for statistics. */
344 	priv->shared->num_wait_free++;
345 
346 	while (!priv->free) {
347 		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
348 
349 		ret = wait_event_interruptible_timeout(priv->wait_free,
350 						       priv->free, HZ*4);
351 
352 		if (ret < 0)
353 			break;
354 
355 		if (ret > 0)
356 			continue;
357 
358 		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr) {
359 			QERROR("TIMEOUT");
360 			ret = -ETIMEDOUT;
361 			break;
362 		}
363 	}
364 
365 	QDUMP("done");
366 
367 	return ret;
368 }
369 
370 /* Misc device layer */
371 
372 static inline struct pxa3xx_gcu_priv *to_pxa3xx_gcu_priv(struct file *file)
373 {
374 	struct miscdevice *dev = file->private_data;
375 	return container_of(dev, struct pxa3xx_gcu_priv, misc_dev);
376 }
377 
378 /*
379  * provide an empty .open callback, so the core sets file->private_data
380  * for us.
381  */
382 static int pxa3xx_gcu_open(struct inode *inode, struct file *file)
383 {
384 	return 0;
385 }
386 
387 static ssize_t
388 pxa3xx_gcu_write(struct file *file, const char *buff,
389 		 size_t count, loff_t *offp)
390 {
391 	int ret;
392 	unsigned long flags;
393 	struct pxa3xx_gcu_batch	*buffer;
394 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
395 
396 	int words = count / 4;
397 
398 	/* Does not need to be atomic. There's a lock in user space,
399 	 * but anyhow, this is just for statistics. */
400 	priv->shared->num_writes++;
401 	priv->shared->num_words += words;
402 
403 	/* Last word reserved for batch buffer end command */
404 	if (words >= PXA3XX_GCU_BATCH_WORDS)
405 		return -E2BIG;
406 
407 	/* Wait for a free buffer */
408 	if (!priv->free) {
409 		ret = pxa3xx_gcu_wait_free(priv);
410 		if (ret < 0)
411 			return ret;
412 	}
413 
414 	/*
415 	 * Get buffer from free list
416 	 */
417 	spin_lock_irqsave(&priv->spinlock, flags);
418 	buffer = priv->free;
419 	priv->free = buffer->next;
420 	spin_unlock_irqrestore(&priv->spinlock, flags);
421 
422 
423 	/* Copy data from user into buffer */
424 	ret = copy_from_user(buffer->ptr, buff, words * 4);
425 	if (ret) {
426 		spin_lock_irqsave(&priv->spinlock, flags);
427 		buffer->next = priv->free;
428 		priv->free = buffer;
429 		spin_unlock_irqrestore(&priv->spinlock, flags);
430 		return -EFAULT;
431 	}
432 
433 	buffer->length = words;
434 
435 	/* Append batch buffer end command */
436 	buffer->ptr[words] = 0x01000000;
437 
438 	/*
439 	 * Add buffer to ready list
440 	 */
441 	spin_lock_irqsave(&priv->spinlock, flags);
442 
443 	buffer->next = NULL;
444 
445 	if (priv->ready) {
446 		BUG_ON(priv->ready_last == NULL);
447 
448 		priv->ready_last->next = buffer;
449 	} else
450 		priv->ready = buffer;
451 
452 	priv->ready_last = buffer;
453 
454 	if (!priv->shared->hw_running)
455 		run_ready(priv);
456 
457 	spin_unlock_irqrestore(&priv->spinlock, flags);
458 
459 	return words * 4;
460 }
461 
462 
463 static long
464 pxa3xx_gcu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
465 {
466 	unsigned long flags;
467 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
468 
469 	switch (cmd) {
470 	case PXA3XX_GCU_IOCTL_RESET:
471 		spin_lock_irqsave(&priv->spinlock, flags);
472 		pxa3xx_gcu_reset(priv);
473 		spin_unlock_irqrestore(&priv->spinlock, flags);
474 		return 0;
475 
476 	case PXA3XX_GCU_IOCTL_WAIT_IDLE:
477 		return pxa3xx_gcu_wait_idle(priv);
478 	}
479 
480 	return -ENOSYS;
481 }
482 
483 static int
484 pxa3xx_gcu_mmap(struct file *file, struct vm_area_struct *vma)
485 {
486 	unsigned int size = vma->vm_end - vma->vm_start;
487 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
488 
489 	switch (vma->vm_pgoff) {
490 	case 0:
491 		/* hand out the shared data area */
492 		if (size != SHARED_SIZE)
493 			return -EINVAL;
494 
495 		return dma_mmap_coherent(NULL, vma,
496 			priv->shared, priv->shared_phys, size);
497 
498 	case SHARED_SIZE >> PAGE_SHIFT:
499 		/* hand out the MMIO base for direct register access
500 		 * from userspace */
501 		if (size != resource_size(priv->resource_mem))
502 			return -EINVAL;
503 
504 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
505 
506 		return io_remap_pfn_range(vma, vma->vm_start,
507 				priv->resource_mem->start >> PAGE_SHIFT,
508 				size, vma->vm_page_prot);
509 	}
510 
511 	return -EINVAL;
512 }
513 
514 
515 #ifdef PXA3XX_GCU_DEBUG_TIMER
516 static struct timer_list pxa3xx_gcu_debug_timer;
517 static struct pxa3xx_gcu_priv *debug_timer_priv;
518 
519 static void pxa3xx_gcu_debug_timedout(struct timer_list *unused)
520 {
521 	struct pxa3xx_gcu_priv *priv = debug_timer_priv;
522 
523 	QERROR("Timer DUMP");
524 
525 	mod_timer(&pxa3xx_gcu_debug_timer, jiffies + 5 * HZ);
526 }
527 
528 static void pxa3xx_gcu_init_debug_timer(struct pxa3xx_gcu_priv *priv)
529 {
530 	/* init the timer structure */
531 	debug_timer_priv = priv;
532 	timer_setup(&pxa3xx_gcu_debug_timer, pxa3xx_gcu_debug_timedout, 0);
533 	pxa3xx_gcu_debug_timedout(NULL);
534 }
535 #else
536 static inline void pxa3xx_gcu_init_debug_timer(struct pxa3xx_gcu_priv *priv) {}
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: %d\n", irq);
630 		return irq;
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_prepare_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(priv);
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_unprepare(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 		.name   = DRV_NAME,
711 	},
712 };
713 
714 module_platform_driver(pxa3xx_gcu_driver);
715 
716 MODULE_DESCRIPTION("PXA3xx graphics controller unit driver");
717 MODULE_LICENSE("GPL");
718 MODULE_ALIAS_MISCDEV(MISCDEV_MINOR);
719 MODULE_AUTHOR("Janine Kropp <nin@directfb.org>, "
720 		"Denis Oliver Kropp <dok@directfb.org>, "
721 		"Daniel Mack <daniel@caiaq.de>");
722