xref: /openbmc/linux/drivers/video/fbdev/pxa3xx-gcu.c (revision 07c7c6bf)
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 #include <linux/of.h>
48 
49 #include "pxa3xx-gcu.h"
50 
51 #define DRV_NAME	"pxa3xx-gcu"
52 #define MISCDEV_MINOR	197
53 
54 #define REG_GCCR	0x00
55 #define GCCR_SYNC_CLR	(1 << 9)
56 #define GCCR_BP_RST	(1 << 8)
57 #define GCCR_ABORT	(1 << 6)
58 #define GCCR_STOP	(1 << 4)
59 
60 #define REG_GCISCR	0x04
61 #define REG_GCIECR	0x08
62 #define REG_GCRBBR	0x20
63 #define REG_GCRBLR	0x24
64 #define REG_GCRBHR	0x28
65 #define REG_GCRBTR	0x2C
66 #define REG_GCRBEXHR	0x30
67 
68 #define IE_EOB		(1 << 0)
69 #define IE_EEOB		(1 << 5)
70 #define IE_ALL		0xff
71 
72 #define SHARED_SIZE	PAGE_ALIGN(sizeof(struct pxa3xx_gcu_shared))
73 
74 /* #define PXA3XX_GCU_DEBUG */
75 /* #define PXA3XX_GCU_DEBUG_TIMER */
76 
77 #ifdef PXA3XX_GCU_DEBUG
78 #define QDUMP(msg)					\
79 	do {						\
80 		QPRINT(priv, KERN_DEBUG, msg);		\
81 	} while (0)
82 #else
83 #define QDUMP(msg)	do {} while (0)
84 #endif
85 
86 #define QERROR(msg)					\
87 	do {						\
88 		QPRINT(priv, KERN_ERR, msg);		\
89 	} while (0)
90 
91 struct pxa3xx_gcu_batch {
92 	struct pxa3xx_gcu_batch *next;
93 	u32			*ptr;
94 	dma_addr_t		 phys;
95 	unsigned long		 length;
96 };
97 
98 struct pxa3xx_gcu_priv {
99 	struct device		 *dev;
100 	void __iomem		 *mmio_base;
101 	struct clk		 *clk;
102 	struct pxa3xx_gcu_shared *shared;
103 	dma_addr_t		  shared_phys;
104 	struct resource		 *resource_mem;
105 	struct miscdevice	  misc_dev;
106 	wait_queue_head_t	  wait_idle;
107 	wait_queue_head_t	  wait_free;
108 	spinlock_t		  spinlock;
109 	struct timespec64	  base_time;
110 
111 	struct pxa3xx_gcu_batch *free;
112 	struct pxa3xx_gcu_batch *ready;
113 	struct pxa3xx_gcu_batch *ready_last;
114 	struct pxa3xx_gcu_batch *running;
115 };
116 
117 static inline unsigned long
118 gc_readl(struct pxa3xx_gcu_priv *priv, unsigned int off)
119 {
120 	return __raw_readl(priv->mmio_base + off);
121 }
122 
123 static inline void
124 gc_writel(struct pxa3xx_gcu_priv *priv, unsigned int off, unsigned long val)
125 {
126 	__raw_writel(val, priv->mmio_base + off);
127 }
128 
129 #define QPRINT(priv, level, msg)					\
130 	do {								\
131 		struct timespec64 ts;					\
132 		struct pxa3xx_gcu_shared *shared = priv->shared;	\
133 		u32 base = gc_readl(priv, REG_GCRBBR);			\
134 									\
135 		ktime_get_ts64(&ts);					\
136 		ts = timespec64_sub(ts, priv->base_time);		\
137 									\
138 		printk(level "%lld.%03ld.%03ld - %-17s: %-21s (%s, "	\
139 			"STATUS "					\
140 			"0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, "	\
141 			"T %5ld)\n",					\
142 			(s64)(ts.tv_sec),				\
143 			ts.tv_nsec / NSEC_PER_MSEC,			\
144 			(ts.tv_nsec % NSEC_PER_MSEC) / USEC_PER_MSEC,	\
145 			__func__, msg,					\
146 			shared->hw_running ? "running" : "   idle",	\
147 			gc_readl(priv, REG_GCISCR),			\
148 			gc_readl(priv, REG_GCRBBR),			\
149 			gc_readl(priv, REG_GCRBLR),			\
150 			(gc_readl(priv, REG_GCRBEXHR) - base) / 4,	\
151 			(gc_readl(priv, REG_GCRBHR) - base) / 4,	\
152 			(gc_readl(priv, REG_GCRBTR) - base) / 4);	\
153 	} while (0)
154 
155 static void
156 pxa3xx_gcu_reset(struct pxa3xx_gcu_priv *priv)
157 {
158 	QDUMP("RESET");
159 
160 	/* disable interrupts */
161 	gc_writel(priv, REG_GCIECR, 0);
162 
163 	/* reset hardware */
164 	gc_writel(priv, REG_GCCR, GCCR_ABORT);
165 	gc_writel(priv, REG_GCCR, 0);
166 
167 	memset(priv->shared, 0, SHARED_SIZE);
168 	priv->shared->buffer_phys = priv->shared_phys;
169 	priv->shared->magic = PXA3XX_GCU_SHARED_MAGIC;
170 
171 	ktime_get_ts64(&priv->base_time);
172 
173 	/* set up the ring buffer pointers */
174 	gc_writel(priv, REG_GCRBLR, 0);
175 	gc_writel(priv, REG_GCRBBR, priv->shared_phys);
176 	gc_writel(priv, REG_GCRBTR, priv->shared_phys);
177 
178 	/* enable all IRQs except EOB */
179 	gc_writel(priv, REG_GCIECR, IE_ALL & ~IE_EOB);
180 }
181 
182 static void
183 dump_whole_state(struct pxa3xx_gcu_priv *priv)
184 {
185 	struct pxa3xx_gcu_shared *sh = priv->shared;
186 	u32 base = gc_readl(priv, REG_GCRBBR);
187 
188 	QDUMP("DUMP");
189 
190 	printk(KERN_DEBUG "== PXA3XX-GCU DUMP ==\n"
191 		"%s, STATUS 0x%02lx, B 0x%08lx [%ld], E %5ld, H %5ld, T %5ld\n",
192 		sh->hw_running ? "running" : "idle   ",
193 		gc_readl(priv, REG_GCISCR),
194 		gc_readl(priv, REG_GCRBBR),
195 		gc_readl(priv, REG_GCRBLR),
196 		(gc_readl(priv, REG_GCRBEXHR) - base) / 4,
197 		(gc_readl(priv, REG_GCRBHR) - base) / 4,
198 		(gc_readl(priv, REG_GCRBTR) - base) / 4);
199 }
200 
201 static void
202 flush_running(struct pxa3xx_gcu_priv *priv)
203 {
204 	struct pxa3xx_gcu_batch *running = priv->running;
205 	struct pxa3xx_gcu_batch *next;
206 
207 	while (running) {
208 		next = running->next;
209 		running->next = priv->free;
210 		priv->free = running;
211 		running = next;
212 	}
213 
214 	priv->running = NULL;
215 }
216 
217 static void
218 run_ready(struct pxa3xx_gcu_priv *priv)
219 {
220 	unsigned int num = 0;
221 	struct pxa3xx_gcu_shared *shared = priv->shared;
222 	struct pxa3xx_gcu_batch	*ready = priv->ready;
223 
224 	QDUMP("Start");
225 
226 	BUG_ON(!ready);
227 
228 	shared->buffer[num++] = 0x05000000;
229 
230 	while (ready) {
231 		shared->buffer[num++] = 0x00000001;
232 		shared->buffer[num++] = ready->phys;
233 		ready = ready->next;
234 	}
235 
236 	shared->buffer[num++] = 0x05000000;
237 	priv->running = priv->ready;
238 	priv->ready = priv->ready_last = NULL;
239 	gc_writel(priv, REG_GCRBLR, 0);
240 	shared->hw_running = 1;
241 
242 	/* ring base address */
243 	gc_writel(priv, REG_GCRBBR, shared->buffer_phys);
244 
245 	/* ring tail address */
246 	gc_writel(priv, REG_GCRBTR, shared->buffer_phys + num * 4);
247 
248 	/* ring length */
249 	gc_writel(priv, REG_GCRBLR, ((num + 63) & ~63) * 4);
250 }
251 
252 static irqreturn_t
253 pxa3xx_gcu_handle_irq(int irq, void *ctx)
254 {
255 	struct pxa3xx_gcu_priv *priv = ctx;
256 	struct pxa3xx_gcu_shared *shared = priv->shared;
257 	u32 status = gc_readl(priv, REG_GCISCR) & IE_ALL;
258 
259 	QDUMP("-Interrupt");
260 
261 	if (!status)
262 		return IRQ_NONE;
263 
264 	spin_lock(&priv->spinlock);
265 	shared->num_interrupts++;
266 
267 	if (status & IE_EEOB) {
268 		QDUMP(" [EEOB]");
269 
270 		flush_running(priv);
271 		wake_up_all(&priv->wait_free);
272 
273 		if (priv->ready) {
274 			run_ready(priv);
275 		} else {
276 			/* There is no more data prepared by the userspace.
277 			 * Set hw_running = 0 and wait for the next userspace
278 			 * kick-off */
279 			shared->num_idle++;
280 			shared->hw_running = 0;
281 
282 			QDUMP(" '-> Idle.");
283 
284 			/* set ring buffer length to zero */
285 			gc_writel(priv, REG_GCRBLR, 0);
286 
287 			wake_up_all(&priv->wait_idle);
288 		}
289 
290 		shared->num_done++;
291 	} else {
292 		QERROR(" [???]");
293 		dump_whole_state(priv);
294 	}
295 
296 	/* Clear the interrupt */
297 	gc_writel(priv, REG_GCISCR, status);
298 	spin_unlock(&priv->spinlock);
299 
300 	return IRQ_HANDLED;
301 }
302 
303 static int
304 pxa3xx_gcu_wait_idle(struct pxa3xx_gcu_priv *priv)
305 {
306 	int ret = 0;
307 
308 	QDUMP("Waiting for idle...");
309 
310 	/* Does not need to be atomic. There's a lock in user space,
311 	 * but anyhow, this is just for statistics. */
312 	priv->shared->num_wait_idle++;
313 
314 	while (priv->shared->hw_running) {
315 		int num = priv->shared->num_interrupts;
316 		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
317 
318 		ret = wait_event_interruptible_timeout(priv->wait_idle,
319 					!priv->shared->hw_running, HZ*4);
320 
321 		if (ret != 0)
322 			break;
323 
324 		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr &&
325 		    priv->shared->num_interrupts == num) {
326 			QERROR("TIMEOUT");
327 			ret = -ETIMEDOUT;
328 			break;
329 		}
330 	}
331 
332 	QDUMP("done");
333 
334 	return ret;
335 }
336 
337 static int
338 pxa3xx_gcu_wait_free(struct pxa3xx_gcu_priv *priv)
339 {
340 	int ret = 0;
341 
342 	QDUMP("Waiting for free...");
343 
344 	/* Does not need to be atomic. There's a lock in user space,
345 	 * but anyhow, this is just for statistics. */
346 	priv->shared->num_wait_free++;
347 
348 	while (!priv->free) {
349 		u32 rbexhr = gc_readl(priv, REG_GCRBEXHR);
350 
351 		ret = wait_event_interruptible_timeout(priv->wait_free,
352 						       priv->free, HZ*4);
353 
354 		if (ret < 0)
355 			break;
356 
357 		if (ret > 0)
358 			continue;
359 
360 		if (gc_readl(priv, REG_GCRBEXHR) == rbexhr) {
361 			QERROR("TIMEOUT");
362 			ret = -ETIMEDOUT;
363 			break;
364 		}
365 	}
366 
367 	QDUMP("done");
368 
369 	return ret;
370 }
371 
372 /* Misc device layer */
373 
374 static inline struct pxa3xx_gcu_priv *to_pxa3xx_gcu_priv(struct file *file)
375 {
376 	struct miscdevice *dev = file->private_data;
377 	return container_of(dev, struct pxa3xx_gcu_priv, misc_dev);
378 }
379 
380 /*
381  * provide an empty .open callback, so the core sets file->private_data
382  * for us.
383  */
384 static int pxa3xx_gcu_open(struct inode *inode, struct file *file)
385 {
386 	return 0;
387 }
388 
389 static ssize_t
390 pxa3xx_gcu_write(struct file *file, const char *buff,
391 		 size_t count, loff_t *offp)
392 {
393 	int ret;
394 	unsigned long flags;
395 	struct pxa3xx_gcu_batch	*buffer;
396 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
397 
398 	int words = count / 4;
399 
400 	/* Does not need to be atomic. There's a lock in user space,
401 	 * but anyhow, this is just for statistics. */
402 	priv->shared->num_writes++;
403 	priv->shared->num_words += words;
404 
405 	/* Last word reserved for batch buffer end command */
406 	if (words >= PXA3XX_GCU_BATCH_WORDS)
407 		return -E2BIG;
408 
409 	/* Wait for a free buffer */
410 	if (!priv->free) {
411 		ret = pxa3xx_gcu_wait_free(priv);
412 		if (ret < 0)
413 			return ret;
414 	}
415 
416 	/*
417 	 * Get buffer from free list
418 	 */
419 	spin_lock_irqsave(&priv->spinlock, flags);
420 	buffer = priv->free;
421 	priv->free = buffer->next;
422 	spin_unlock_irqrestore(&priv->spinlock, flags);
423 
424 
425 	/* Copy data from user into buffer */
426 	ret = copy_from_user(buffer->ptr, buff, words * 4);
427 	if (ret) {
428 		spin_lock_irqsave(&priv->spinlock, flags);
429 		buffer->next = priv->free;
430 		priv->free = buffer;
431 		spin_unlock_irqrestore(&priv->spinlock, flags);
432 		return -EFAULT;
433 	}
434 
435 	buffer->length = words;
436 
437 	/* Append batch buffer end command */
438 	buffer->ptr[words] = 0x01000000;
439 
440 	/*
441 	 * Add buffer to ready list
442 	 */
443 	spin_lock_irqsave(&priv->spinlock, flags);
444 
445 	buffer->next = NULL;
446 
447 	if (priv->ready) {
448 		BUG_ON(priv->ready_last == NULL);
449 
450 		priv->ready_last->next = buffer;
451 	} else
452 		priv->ready = buffer;
453 
454 	priv->ready_last = buffer;
455 
456 	if (!priv->shared->hw_running)
457 		run_ready(priv);
458 
459 	spin_unlock_irqrestore(&priv->spinlock, flags);
460 
461 	return words * 4;
462 }
463 
464 
465 static long
466 pxa3xx_gcu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
467 {
468 	unsigned long flags;
469 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
470 
471 	switch (cmd) {
472 	case PXA3XX_GCU_IOCTL_RESET:
473 		spin_lock_irqsave(&priv->spinlock, flags);
474 		pxa3xx_gcu_reset(priv);
475 		spin_unlock_irqrestore(&priv->spinlock, flags);
476 		return 0;
477 
478 	case PXA3XX_GCU_IOCTL_WAIT_IDLE:
479 		return pxa3xx_gcu_wait_idle(priv);
480 	}
481 
482 	return -ENOSYS;
483 }
484 
485 static int
486 pxa3xx_gcu_mmap(struct file *file, struct vm_area_struct *vma)
487 {
488 	unsigned int size = vma->vm_end - vma->vm_start;
489 	struct pxa3xx_gcu_priv *priv = to_pxa3xx_gcu_priv(file);
490 
491 	switch (vma->vm_pgoff) {
492 	case 0:
493 		/* hand out the shared data area */
494 		if (size != SHARED_SIZE)
495 			return -EINVAL;
496 
497 		return dma_mmap_coherent(priv->dev, vma,
498 			priv->shared, priv->shared_phys, size);
499 
500 	case SHARED_SIZE >> PAGE_SHIFT:
501 		/* hand out the MMIO base for direct register access
502 		 * from userspace */
503 		if (size != resource_size(priv->resource_mem))
504 			return -EINVAL;
505 
506 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
507 
508 		return io_remap_pfn_range(vma, vma->vm_start,
509 				priv->resource_mem->start >> PAGE_SHIFT,
510 				size, vma->vm_page_prot);
511 	}
512 
513 	return -EINVAL;
514 }
515 
516 
517 #ifdef PXA3XX_GCU_DEBUG_TIMER
518 static struct timer_list pxa3xx_gcu_debug_timer;
519 static struct pxa3xx_gcu_priv *debug_timer_priv;
520 
521 static void pxa3xx_gcu_debug_timedout(struct timer_list *unused)
522 {
523 	struct pxa3xx_gcu_priv *priv = debug_timer_priv;
524 
525 	QERROR("Timer DUMP");
526 
527 	mod_timer(&pxa3xx_gcu_debug_timer, jiffies + 5 * HZ);
528 }
529 
530 static void pxa3xx_gcu_init_debug_timer(struct pxa3xx_gcu_priv *priv)
531 {
532 	/* init the timer structure */
533 	debug_timer_priv = priv;
534 	timer_setup(&pxa3xx_gcu_debug_timer, pxa3xx_gcu_debug_timedout, 0);
535 	pxa3xx_gcu_debug_timedout(NULL);
536 }
537 #else
538 static inline void pxa3xx_gcu_init_debug_timer(struct pxa3xx_gcu_priv *priv) {}
539 #endif
540 
541 static int
542 pxa3xx_gcu_add_buffer(struct device *dev,
543 		      struct pxa3xx_gcu_priv *priv)
544 {
545 	struct pxa3xx_gcu_batch *buffer;
546 
547 	buffer = kzalloc(sizeof(struct pxa3xx_gcu_batch), GFP_KERNEL);
548 	if (!buffer)
549 		return -ENOMEM;
550 
551 	buffer->ptr = dma_alloc_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4,
552 					 &buffer->phys, GFP_KERNEL);
553 	if (!buffer->ptr) {
554 		kfree(buffer);
555 		return -ENOMEM;
556 	}
557 
558 	buffer->next = priv->free;
559 	priv->free = buffer;
560 
561 	return 0;
562 }
563 
564 static void
565 pxa3xx_gcu_free_buffers(struct device *dev,
566 			struct pxa3xx_gcu_priv *priv)
567 {
568 	struct pxa3xx_gcu_batch *next, *buffer = priv->free;
569 
570 	while (buffer) {
571 		next = buffer->next;
572 
573 		dma_free_coherent(dev, PXA3XX_GCU_BATCH_WORDS * 4,
574 				  buffer->ptr, buffer->phys);
575 
576 		kfree(buffer);
577 		buffer = next;
578 	}
579 
580 	priv->free = NULL;
581 }
582 
583 static const struct file_operations pxa3xx_gcu_miscdev_fops = {
584 	.owner =		THIS_MODULE,
585 	.open =			pxa3xx_gcu_open,
586 	.write =		pxa3xx_gcu_write,
587 	.unlocked_ioctl =	pxa3xx_gcu_ioctl,
588 	.mmap =			pxa3xx_gcu_mmap,
589 };
590 
591 static int pxa3xx_gcu_probe(struct platform_device *pdev)
592 {
593 	int i, ret, irq;
594 	struct resource *r;
595 	struct pxa3xx_gcu_priv *priv;
596 	struct device *dev = &pdev->dev;
597 
598 	priv = devm_kzalloc(dev, sizeof(struct pxa3xx_gcu_priv), GFP_KERNEL);
599 	if (!priv)
600 		return -ENOMEM;
601 
602 	init_waitqueue_head(&priv->wait_idle);
603 	init_waitqueue_head(&priv->wait_free);
604 	spin_lock_init(&priv->spinlock);
605 
606 	/* we allocate the misc device structure as part of our own allocation,
607 	 * so we can get a pointer to our priv structure later on with
608 	 * container_of(). This isn't really necessary as we have a fixed minor
609 	 * number anyway, but this is to avoid statics. */
610 
611 	priv->misc_dev.minor	= MISCDEV_MINOR,
612 	priv->misc_dev.name	= DRV_NAME,
613 	priv->misc_dev.fops	= &pxa3xx_gcu_miscdev_fops;
614 
615 	/* handle IO resources */
616 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
617 	priv->mmio_base = devm_ioremap_resource(dev, r);
618 	if (IS_ERR(priv->mmio_base))
619 		return PTR_ERR(priv->mmio_base);
620 
621 	/* enable the clock */
622 	priv->clk = devm_clk_get(dev, NULL);
623 	if (IS_ERR(priv->clk)) {
624 		dev_err(dev, "failed to get clock\n");
625 		return PTR_ERR(priv->clk);
626 	}
627 
628 	/* request the IRQ */
629 	irq = platform_get_irq(pdev, 0);
630 	if (irq < 0) {
631 		dev_err(dev, "no IRQ defined: %d\n", irq);
632 		return irq;
633 	}
634 
635 	ret = devm_request_irq(dev, irq, pxa3xx_gcu_handle_irq,
636 			       0, DRV_NAME, priv);
637 	if (ret < 0) {
638 		dev_err(dev, "request_irq failed\n");
639 		return ret;
640 	}
641 
642 	/* allocate dma memory */
643 	priv->shared = dma_alloc_coherent(dev, SHARED_SIZE,
644 					  &priv->shared_phys, GFP_KERNEL);
645 	if (!priv->shared) {
646 		dev_err(dev, "failed to allocate DMA memory\n");
647 		return -ENOMEM;
648 	}
649 
650 	/* register misc device */
651 	ret = misc_register(&priv->misc_dev);
652 	if (ret < 0) {
653 		dev_err(dev, "misc_register() for minor %d failed\n",
654 			MISCDEV_MINOR);
655 		goto err_free_dma;
656 	}
657 
658 	ret = clk_prepare_enable(priv->clk);
659 	if (ret < 0) {
660 		dev_err(dev, "failed to enable clock\n");
661 		goto err_misc_deregister;
662 	}
663 
664 	for (i = 0; i < 8; i++) {
665 		ret = pxa3xx_gcu_add_buffer(dev, priv);
666 		if (ret) {
667 			dev_err(dev, "failed to allocate DMA memory\n");
668 			goto err_disable_clk;
669 		}
670 	}
671 
672 	platform_set_drvdata(pdev, priv);
673 	priv->resource_mem = r;
674 	priv->dev = dev;
675 	pxa3xx_gcu_reset(priv);
676 	pxa3xx_gcu_init_debug_timer(priv);
677 
678 	dev_info(dev, "registered @0x%p, DMA 0x%p (%d bytes), IRQ %d\n",
679 			(void *) r->start, (void *) priv->shared_phys,
680 			SHARED_SIZE, irq);
681 	return 0;
682 
683 err_free_dma:
684 	dma_free_coherent(dev, SHARED_SIZE,
685 			priv->shared, priv->shared_phys);
686 
687 err_misc_deregister:
688 	misc_deregister(&priv->misc_dev);
689 
690 err_disable_clk:
691 	clk_disable_unprepare(priv->clk);
692 
693 	return ret;
694 }
695 
696 static int pxa3xx_gcu_remove(struct platform_device *pdev)
697 {
698 	struct pxa3xx_gcu_priv *priv = platform_get_drvdata(pdev);
699 	struct device *dev = &pdev->dev;
700 
701 	pxa3xx_gcu_wait_idle(priv);
702 	misc_deregister(&priv->misc_dev);
703 	dma_free_coherent(dev, SHARED_SIZE, priv->shared, priv->shared_phys);
704 	pxa3xx_gcu_free_buffers(dev, priv);
705 
706 	return 0;
707 }
708 
709 #ifdef CONFIG_OF
710 static const struct of_device_id pxa3xx_gcu_of_match[] = {
711 	{ .compatible = "marvell,pxa300-gcu", },
712 	{ }
713 };
714 MODULE_DEVICE_TABLE(of, pxa3xx_gcu_of_match);
715 #endif
716 
717 static struct platform_driver pxa3xx_gcu_driver = {
718 	.probe	  = pxa3xx_gcu_probe,
719 	.remove	 = pxa3xx_gcu_remove,
720 	.driver	 = {
721 		.name   = DRV_NAME,
722 		.of_match_table = of_match_ptr(pxa3xx_gcu_of_match),
723 	},
724 };
725 
726 module_platform_driver(pxa3xx_gcu_driver);
727 
728 MODULE_DESCRIPTION("PXA3xx graphics controller unit driver");
729 MODULE_LICENSE("GPL");
730 MODULE_ALIAS_MISCDEV(MISCDEV_MINOR);
731 MODULE_AUTHOR("Janine Kropp <nin@directfb.org>, "
732 		"Denis Oliver Kropp <dok@directfb.org>, "
733 		"Daniel Mack <daniel@caiaq.de>");
734