xref: /openbmc/linux/drivers/fpga/zynq-fpga.c (revision 829c6524)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2011-2015 Xilinx Inc.
4  * Copyright (c) 2015, National Instruments Corp.
5  *
6  * FPGA Manager Driver for Xilinx Zynq, heavily based on xdevcfg driver
7  * in their vendor tree.
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/completion.h>
12 #include <linux/delay.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/fpga/fpga-mgr.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/iopoll.h>
18 #include <linux/module.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/of_address.h>
21 #include <linux/of_irq.h>
22 #include <linux/pm.h>
23 #include <linux/regmap.h>
24 #include <linux/string.h>
25 #include <linux/scatterlist.h>
26 
27 /* Offsets into SLCR regmap */
28 
29 /* FPGA Software Reset Control */
30 #define SLCR_FPGA_RST_CTRL_OFFSET	0x240
31 /* Level Shifters Enable */
32 #define SLCR_LVL_SHFTR_EN_OFFSET	0x900
33 
34 /* Constant Definitions */
35 
36 /* Control Register */
37 #define CTRL_OFFSET			0x00
38 /* Lock Register */
39 #define LOCK_OFFSET			0x04
40 /* Interrupt Status Register */
41 #define INT_STS_OFFSET			0x0c
42 /* Interrupt Mask Register */
43 #define INT_MASK_OFFSET			0x10
44 /* Status Register */
45 #define STATUS_OFFSET			0x14
46 /* DMA Source Address Register */
47 #define DMA_SRC_ADDR_OFFSET		0x18
48 /* DMA Destination Address Reg */
49 #define DMA_DST_ADDR_OFFSET		0x1c
50 /* DMA Source Transfer Length */
51 #define DMA_SRC_LEN_OFFSET		0x20
52 /* DMA Destination Transfer */
53 #define DMA_DEST_LEN_OFFSET		0x24
54 /* Unlock Register */
55 #define UNLOCK_OFFSET			0x34
56 /* Misc. Control Register */
57 #define MCTRL_OFFSET			0x80
58 
59 /* Control Register Bit definitions */
60 
61 /* Signal to reset FPGA */
62 #define CTRL_PCFG_PROG_B_MASK		BIT(30)
63 /* Enable PCAP for PR */
64 #define CTRL_PCAP_PR_MASK		BIT(27)
65 /* Enable PCAP */
66 #define CTRL_PCAP_MODE_MASK		BIT(26)
67 /* Lower rate to allow decrypt on the fly */
68 #define CTRL_PCAP_RATE_EN_MASK		BIT(25)
69 /* System booted in secure mode */
70 #define CTRL_SEC_EN_MASK		BIT(7)
71 
72 /* Miscellaneous Control Register bit definitions */
73 /* Internal PCAP loopback */
74 #define MCTRL_PCAP_LPBK_MASK		BIT(4)
75 
76 /* Status register bit definitions */
77 
78 /* FPGA init status */
79 #define STATUS_DMA_Q_F			BIT(31)
80 #define STATUS_DMA_Q_E			BIT(30)
81 #define STATUS_PCFG_INIT_MASK		BIT(4)
82 
83 /* Interrupt Status/Mask Register Bit definitions */
84 /* DMA command done */
85 #define IXR_DMA_DONE_MASK		BIT(13)
86 /* DMA and PCAP cmd done */
87 #define IXR_D_P_DONE_MASK		BIT(12)
88  /* FPGA programmed */
89 #define IXR_PCFG_DONE_MASK		BIT(2)
90 #define IXR_ERROR_FLAGS_MASK		0x00F0C860
91 #define IXR_ALL_MASK			0xF8F7F87F
92 
93 /* Miscellaneous constant values */
94 
95 /* Invalid DMA addr */
96 #define DMA_INVALID_ADDRESS		GENMASK(31, 0)
97 /* Used to unlock the dev */
98 #define UNLOCK_MASK			0x757bdf0d
99 /* Timeout for polling reset bits */
100 #define INIT_POLL_TIMEOUT		2500000
101 /* Delay for polling reset bits */
102 #define INIT_POLL_DELAY			20
103 /* Signal this is the last DMA transfer, wait for the AXI and PCAP before
104  * interrupting
105  */
106 #define DMA_SRC_LAST_TRANSFER		1
107 /* Timeout for DMA completion */
108 #define DMA_TIMEOUT_MS			5000
109 
110 /* Masks for controlling stuff in SLCR */
111 /* Disable all Level shifters */
112 #define LVL_SHFTR_DISABLE_ALL_MASK	0x0
113 /* Enable Level shifters from PS to PL */
114 #define LVL_SHFTR_ENABLE_PS_TO_PL	0xa
115 /* Enable Level shifters from PL to PS */
116 #define LVL_SHFTR_ENABLE_PL_TO_PS	0xf
117 /* Enable global resets */
118 #define FPGA_RST_ALL_MASK		0xf
119 /* Disable global resets */
120 #define FPGA_RST_NONE_MASK		0x0
121 
122 struct zynq_fpga_priv {
123 	int irq;
124 	struct clk *clk;
125 
126 	void __iomem *io_base;
127 	struct regmap *slcr;
128 
129 	spinlock_t dma_lock;
130 	unsigned int dma_elm;
131 	unsigned int dma_nelms;
132 	struct scatterlist *cur_sg;
133 
134 	struct completion dma_done;
135 };
136 
137 static inline void zynq_fpga_write(struct zynq_fpga_priv *priv, u32 offset,
138 				   u32 val)
139 {
140 	writel(val, priv->io_base + offset);
141 }
142 
143 static inline u32 zynq_fpga_read(const struct zynq_fpga_priv *priv,
144 				 u32 offset)
145 {
146 	return readl(priv->io_base + offset);
147 }
148 
149 #define zynq_fpga_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
150 	readl_poll_timeout(priv->io_base + addr, val, cond, sleep_us, \
151 			   timeout_us)
152 
153 /* Cause the specified irq mask bits to generate IRQs */
154 static inline void zynq_fpga_set_irq(struct zynq_fpga_priv *priv, u32 enable)
155 {
156 	zynq_fpga_write(priv, INT_MASK_OFFSET, ~enable);
157 }
158 
159 /* Must be called with dma_lock held */
160 static void zynq_step_dma(struct zynq_fpga_priv *priv)
161 {
162 	u32 addr;
163 	u32 len;
164 	bool first;
165 
166 	first = priv->dma_elm == 0;
167 	while (priv->cur_sg) {
168 		/* Feed the DMA queue until it is full. */
169 		if (zynq_fpga_read(priv, STATUS_OFFSET) & STATUS_DMA_Q_F)
170 			break;
171 
172 		addr = sg_dma_address(priv->cur_sg);
173 		len = sg_dma_len(priv->cur_sg);
174 		if (priv->dma_elm + 1 == priv->dma_nelms) {
175 			/* The last transfer waits for the PCAP to finish too,
176 			 * notice this also changes the irq_mask to ignore
177 			 * IXR_DMA_DONE_MASK which ensures we do not trigger
178 			 * the completion too early.
179 			 */
180 			addr |= DMA_SRC_LAST_TRANSFER;
181 			priv->cur_sg = NULL;
182 		} else {
183 			priv->cur_sg = sg_next(priv->cur_sg);
184 			priv->dma_elm++;
185 		}
186 
187 		zynq_fpga_write(priv, DMA_SRC_ADDR_OFFSET, addr);
188 		zynq_fpga_write(priv, DMA_DST_ADDR_OFFSET, DMA_INVALID_ADDRESS);
189 		zynq_fpga_write(priv, DMA_SRC_LEN_OFFSET, len / 4);
190 		zynq_fpga_write(priv, DMA_DEST_LEN_OFFSET, 0);
191 	}
192 
193 	/* Once the first transfer is queued we can turn on the ISR, future
194 	 * calls to zynq_step_dma will happen from the ISR context. The
195 	 * dma_lock spinlock guarantees this handover is done coherently, the
196 	 * ISR enable is put at the end to avoid another CPU spinning in the
197 	 * ISR on this lock.
198 	 */
199 	if (first && priv->cur_sg) {
200 		zynq_fpga_set_irq(priv,
201 				  IXR_DMA_DONE_MASK | IXR_ERROR_FLAGS_MASK);
202 	} else if (!priv->cur_sg) {
203 		/* The last transfer changes to DMA & PCAP mode since we do
204 		 * not want to continue until everything has been flushed into
205 		 * the PCAP.
206 		 */
207 		zynq_fpga_set_irq(priv,
208 				  IXR_D_P_DONE_MASK | IXR_ERROR_FLAGS_MASK);
209 	}
210 }
211 
212 static irqreturn_t zynq_fpga_isr(int irq, void *data)
213 {
214 	struct zynq_fpga_priv *priv = data;
215 	u32 intr_status;
216 
217 	/* If anything other than DMA completion is reported stop and hand
218 	 * control back to zynq_fpga_ops_write, something went wrong,
219 	 * otherwise progress the DMA.
220 	 */
221 	spin_lock(&priv->dma_lock);
222 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
223 	if (!(intr_status & IXR_ERROR_FLAGS_MASK) &&
224 	    (intr_status & IXR_DMA_DONE_MASK) && priv->cur_sg) {
225 		zynq_fpga_write(priv, INT_STS_OFFSET, IXR_DMA_DONE_MASK);
226 		zynq_step_dma(priv);
227 		spin_unlock(&priv->dma_lock);
228 		return IRQ_HANDLED;
229 	}
230 	spin_unlock(&priv->dma_lock);
231 
232 	zynq_fpga_set_irq(priv, 0);
233 	complete(&priv->dma_done);
234 
235 	return IRQ_HANDLED;
236 }
237 
238 /* Sanity check the proposed bitstream. It must start with the sync word in
239  * the correct byte order, and be dword aligned. The input is a Xilinx .bin
240  * file with every 32 bit quantity swapped.
241  */
242 static bool zynq_fpga_has_sync(const u8 *buf, size_t count)
243 {
244 	for (; count >= 4; buf += 4, count -= 4)
245 		if (buf[0] == 0x66 && buf[1] == 0x55 && buf[2] == 0x99 &&
246 		    buf[3] == 0xaa)
247 			return true;
248 	return false;
249 }
250 
251 static int zynq_fpga_ops_write_init(struct fpga_manager *mgr,
252 				    struct fpga_image_info *info,
253 				    const char *buf, size_t count)
254 {
255 	struct zynq_fpga_priv *priv;
256 	u32 ctrl, status;
257 	int err;
258 
259 	priv = mgr->priv;
260 
261 	err = clk_enable(priv->clk);
262 	if (err)
263 		return err;
264 
265 	/* check if bitstream is encrypted & and system's still secure */
266 	if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM) {
267 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
268 		if (!(ctrl & CTRL_SEC_EN_MASK)) {
269 			dev_err(&mgr->dev,
270 				"System not secure, can't use encrypted bitstreams\n");
271 			err = -EINVAL;
272 			goto out_err;
273 		}
274 	}
275 
276 	/* don't globally reset PL if we're doing partial reconfig */
277 	if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
278 		if (!zynq_fpga_has_sync(buf, count)) {
279 			dev_err(&mgr->dev,
280 				"Invalid bitstream, could not find a sync word. Bitstream must be a byte swapped .bin file\n");
281 			err = -EINVAL;
282 			goto out_err;
283 		}
284 
285 		/* assert AXI interface resets */
286 		regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
287 			     FPGA_RST_ALL_MASK);
288 
289 		/* disable all level shifters */
290 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
291 			     LVL_SHFTR_DISABLE_ALL_MASK);
292 		/* enable level shifters from PS to PL */
293 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
294 			     LVL_SHFTR_ENABLE_PS_TO_PL);
295 
296 		/* create a rising edge on PCFG_INIT. PCFG_INIT follows
297 		 * PCFG_PROG_B, so we need to poll it after setting PCFG_PROG_B
298 		 * to make sure the rising edge actually happens.
299 		 * Note: PCFG_PROG_B is low active, sequence as described in
300 		 * UG585 v1.10 page 211
301 		 */
302 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
303 		ctrl |= CTRL_PCFG_PROG_B_MASK;
304 
305 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
306 
307 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
308 					     status & STATUS_PCFG_INIT_MASK,
309 					     INIT_POLL_DELAY,
310 					     INIT_POLL_TIMEOUT);
311 		if (err) {
312 			dev_err(&mgr->dev, "Timeout waiting for PCFG_INIT\n");
313 			goto out_err;
314 		}
315 
316 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
317 		ctrl &= ~CTRL_PCFG_PROG_B_MASK;
318 
319 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
320 
321 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
322 					     !(status & STATUS_PCFG_INIT_MASK),
323 					     INIT_POLL_DELAY,
324 					     INIT_POLL_TIMEOUT);
325 		if (err) {
326 			dev_err(&mgr->dev, "Timeout waiting for !PCFG_INIT\n");
327 			goto out_err;
328 		}
329 
330 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
331 		ctrl |= CTRL_PCFG_PROG_B_MASK;
332 
333 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
334 
335 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
336 					     status & STATUS_PCFG_INIT_MASK,
337 					     INIT_POLL_DELAY,
338 					     INIT_POLL_TIMEOUT);
339 		if (err) {
340 			dev_err(&mgr->dev, "Timeout waiting for PCFG_INIT\n");
341 			goto out_err;
342 		}
343 	}
344 
345 	/* set configuration register with following options:
346 	 * - enable PCAP interface
347 	 * - set throughput for maximum speed (if bistream not encrypted)
348 	 * - set CPU in user mode
349 	 */
350 	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
351 	if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM)
352 		zynq_fpga_write(priv, CTRL_OFFSET,
353 				(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
354 				 | CTRL_PCAP_RATE_EN_MASK | ctrl));
355 	else
356 		zynq_fpga_write(priv, CTRL_OFFSET,
357 				(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
358 				 | ctrl));
359 
360 
361 	/* We expect that the command queue is empty right now. */
362 	status = zynq_fpga_read(priv, STATUS_OFFSET);
363 	if ((status & STATUS_DMA_Q_F) ||
364 	    (status & STATUS_DMA_Q_E) != STATUS_DMA_Q_E) {
365 		dev_err(&mgr->dev, "DMA command queue not right\n");
366 		err = -EBUSY;
367 		goto out_err;
368 	}
369 
370 	/* ensure internal PCAP loopback is disabled */
371 	ctrl = zynq_fpga_read(priv, MCTRL_OFFSET);
372 	zynq_fpga_write(priv, MCTRL_OFFSET, (~MCTRL_PCAP_LPBK_MASK & ctrl));
373 
374 	clk_disable(priv->clk);
375 
376 	return 0;
377 
378 out_err:
379 	clk_disable(priv->clk);
380 
381 	return err;
382 }
383 
384 static int zynq_fpga_ops_write(struct fpga_manager *mgr, struct sg_table *sgt)
385 {
386 	struct zynq_fpga_priv *priv;
387 	const char *why;
388 	int err;
389 	u32 intr_status;
390 	unsigned long timeout;
391 	unsigned long flags;
392 	struct scatterlist *sg;
393 	int i;
394 
395 	priv = mgr->priv;
396 
397 	/* The hardware can only DMA multiples of 4 bytes, and it requires the
398 	 * starting addresses to be aligned to 64 bits (UG585 pg 212).
399 	 */
400 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
401 		if ((sg->offset % 8) || (sg->length % 4)) {
402 			dev_err(&mgr->dev,
403 			    "Invalid bitstream, chunks must be aligned\n");
404 			return -EINVAL;
405 		}
406 	}
407 
408 	priv->dma_nelms =
409 	    dma_map_sg(mgr->dev.parent, sgt->sgl, sgt->nents, DMA_TO_DEVICE);
410 	if (priv->dma_nelms == 0) {
411 		dev_err(&mgr->dev, "Unable to DMA map (TO_DEVICE)\n");
412 		return -ENOMEM;
413 	}
414 
415 	/* enable clock */
416 	err = clk_enable(priv->clk);
417 	if (err)
418 		goto out_free;
419 
420 	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
421 	reinit_completion(&priv->dma_done);
422 
423 	/* zynq_step_dma will turn on interrupts */
424 	spin_lock_irqsave(&priv->dma_lock, flags);
425 	priv->dma_elm = 0;
426 	priv->cur_sg = sgt->sgl;
427 	zynq_step_dma(priv);
428 	spin_unlock_irqrestore(&priv->dma_lock, flags);
429 
430 	timeout = wait_for_completion_timeout(&priv->dma_done,
431 					      msecs_to_jiffies(DMA_TIMEOUT_MS));
432 
433 	spin_lock_irqsave(&priv->dma_lock, flags);
434 	zynq_fpga_set_irq(priv, 0);
435 	priv->cur_sg = NULL;
436 	spin_unlock_irqrestore(&priv->dma_lock, flags);
437 
438 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
439 	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
440 
441 	/* There doesn't seem to be a way to force cancel any DMA, so if
442 	 * something went wrong we are relying on the hardware to have halted
443 	 * the DMA before we get here, if there was we could use
444 	 * wait_for_completion_interruptible too.
445 	 */
446 
447 	if (intr_status & IXR_ERROR_FLAGS_MASK) {
448 		why = "DMA reported error";
449 		err = -EIO;
450 		goto out_report;
451 	}
452 
453 	if (priv->cur_sg ||
454 	    !((intr_status & IXR_D_P_DONE_MASK) == IXR_D_P_DONE_MASK)) {
455 		if (timeout == 0)
456 			why = "DMA timed out";
457 		else
458 			why = "DMA did not complete";
459 		err = -EIO;
460 		goto out_report;
461 	}
462 
463 	err = 0;
464 	goto out_clk;
465 
466 out_report:
467 	dev_err(&mgr->dev,
468 		"%s: INT_STS:0x%x CTRL:0x%x LOCK:0x%x INT_MASK:0x%x STATUS:0x%x MCTRL:0x%x\n",
469 		why,
470 		intr_status,
471 		zynq_fpga_read(priv, CTRL_OFFSET),
472 		zynq_fpga_read(priv, LOCK_OFFSET),
473 		zynq_fpga_read(priv, INT_MASK_OFFSET),
474 		zynq_fpga_read(priv, STATUS_OFFSET),
475 		zynq_fpga_read(priv, MCTRL_OFFSET));
476 
477 out_clk:
478 	clk_disable(priv->clk);
479 
480 out_free:
481 	dma_unmap_sg(mgr->dev.parent, sgt->sgl, sgt->nents, DMA_TO_DEVICE);
482 	return err;
483 }
484 
485 static int zynq_fpga_ops_write_complete(struct fpga_manager *mgr,
486 					struct fpga_image_info *info)
487 {
488 	struct zynq_fpga_priv *priv = mgr->priv;
489 	int err;
490 	u32 intr_status;
491 
492 	err = clk_enable(priv->clk);
493 	if (err)
494 		return err;
495 
496 	err = zynq_fpga_poll_timeout(priv, INT_STS_OFFSET, intr_status,
497 				     intr_status & IXR_PCFG_DONE_MASK,
498 				     INIT_POLL_DELAY,
499 				     INIT_POLL_TIMEOUT);
500 
501 	/* Release 'PR' control back to the ICAP */
502 	zynq_fpga_write(priv, CTRL_OFFSET,
503 			zynq_fpga_read(priv, CTRL_OFFSET) & ~CTRL_PCAP_PR_MASK);
504 
505 	clk_disable(priv->clk);
506 
507 	if (err)
508 		return err;
509 
510 	/* for the partial reconfig case we didn't touch the level shifters */
511 	if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
512 		/* enable level shifters from PL to PS */
513 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
514 			     LVL_SHFTR_ENABLE_PL_TO_PS);
515 
516 		/* deassert AXI interface resets */
517 		regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
518 			     FPGA_RST_NONE_MASK);
519 	}
520 
521 	return 0;
522 }
523 
524 static enum fpga_mgr_states zynq_fpga_ops_state(struct fpga_manager *mgr)
525 {
526 	int err;
527 	u32 intr_status;
528 	struct zynq_fpga_priv *priv;
529 
530 	priv = mgr->priv;
531 
532 	err = clk_enable(priv->clk);
533 	if (err)
534 		return FPGA_MGR_STATE_UNKNOWN;
535 
536 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
537 	clk_disable(priv->clk);
538 
539 	if (intr_status & IXR_PCFG_DONE_MASK)
540 		return FPGA_MGR_STATE_OPERATING;
541 
542 	return FPGA_MGR_STATE_UNKNOWN;
543 }
544 
545 static const struct fpga_manager_ops zynq_fpga_ops = {
546 	.initial_header_size = 128,
547 	.state = zynq_fpga_ops_state,
548 	.write_init = zynq_fpga_ops_write_init,
549 	.write_sg = zynq_fpga_ops_write,
550 	.write_complete = zynq_fpga_ops_write_complete,
551 };
552 
553 static int zynq_fpga_probe(struct platform_device *pdev)
554 {
555 	struct device *dev = &pdev->dev;
556 	struct zynq_fpga_priv *priv;
557 	struct fpga_manager *mgr;
558 	struct resource *res;
559 	int err;
560 
561 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
562 	if (!priv)
563 		return -ENOMEM;
564 	spin_lock_init(&priv->dma_lock);
565 
566 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
567 	priv->io_base = devm_ioremap_resource(dev, res);
568 	if (IS_ERR(priv->io_base))
569 		return PTR_ERR(priv->io_base);
570 
571 	priv->slcr = syscon_regmap_lookup_by_phandle(dev->of_node,
572 		"syscon");
573 	if (IS_ERR(priv->slcr)) {
574 		dev_err(dev, "unable to get zynq-slcr regmap\n");
575 		return PTR_ERR(priv->slcr);
576 	}
577 
578 	init_completion(&priv->dma_done);
579 
580 	priv->irq = platform_get_irq(pdev, 0);
581 	if (priv->irq < 0)
582 		return priv->irq;
583 
584 	priv->clk = devm_clk_get(dev, "ref_clk");
585 	if (IS_ERR(priv->clk))
586 		return dev_err_probe(dev, PTR_ERR(priv->clk),
587 				     "input clock not found\n");
588 
589 	err = clk_prepare_enable(priv->clk);
590 	if (err) {
591 		dev_err(dev, "unable to enable clock\n");
592 		return err;
593 	}
594 
595 	/* unlock the device */
596 	zynq_fpga_write(priv, UNLOCK_OFFSET, UNLOCK_MASK);
597 
598 	zynq_fpga_set_irq(priv, 0);
599 	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
600 	err = devm_request_irq(dev, priv->irq, zynq_fpga_isr, 0, dev_name(dev),
601 			       priv);
602 	if (err) {
603 		dev_err(dev, "unable to request IRQ\n");
604 		clk_disable_unprepare(priv->clk);
605 		return err;
606 	}
607 
608 	clk_disable(priv->clk);
609 
610 	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
611 				&zynq_fpga_ops, priv);
612 	if (IS_ERR(mgr)) {
613 		dev_err(dev, "unable to register FPGA manager\n");
614 		clk_unprepare(priv->clk);
615 		return PTR_ERR(mgr);
616 	}
617 
618 	platform_set_drvdata(pdev, mgr);
619 
620 	return 0;
621 }
622 
623 static int zynq_fpga_remove(struct platform_device *pdev)
624 {
625 	struct zynq_fpga_priv *priv;
626 	struct fpga_manager *mgr;
627 
628 	mgr = platform_get_drvdata(pdev);
629 	priv = mgr->priv;
630 
631 	fpga_mgr_unregister(mgr);
632 
633 	clk_unprepare(priv->clk);
634 
635 	return 0;
636 }
637 
638 #ifdef CONFIG_OF
639 static const struct of_device_id zynq_fpga_of_match[] = {
640 	{ .compatible = "xlnx,zynq-devcfg-1.0", },
641 	{},
642 };
643 
644 MODULE_DEVICE_TABLE(of, zynq_fpga_of_match);
645 #endif
646 
647 static struct platform_driver zynq_fpga_driver = {
648 	.probe = zynq_fpga_probe,
649 	.remove = zynq_fpga_remove,
650 	.driver = {
651 		.name = "zynq_fpga_manager",
652 		.of_match_table = of_match_ptr(zynq_fpga_of_match),
653 	},
654 };
655 
656 module_platform_driver(zynq_fpga_driver);
657 
658 MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
659 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
660 MODULE_DESCRIPTION("Xilinx Zynq FPGA Manager");
661 MODULE_LICENSE("GPL v2");
662