xref: /openbmc/linux/drivers/fpga/zynq-fpga.c (revision f7d84fa7)
1 /*
2  * Copyright (c) 2011-2015 Xilinx Inc.
3  * Copyright (c) 2015, National Instruments Corp.
4  *
5  * FPGA Manager Driver for Xilinx Zynq, heavily based on xdevcfg driver
6  * in their vendor tree.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/clk.h>
19 #include <linux/completion.h>
20 #include <linux/delay.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/fpga/fpga-mgr.h>
23 #include <linux/interrupt.h>
24 #include <linux/io.h>
25 #include <linux/iopoll.h>
26 #include <linux/module.h>
27 #include <linux/mfd/syscon.h>
28 #include <linux/of_address.h>
29 #include <linux/of_irq.h>
30 #include <linux/pm.h>
31 #include <linux/regmap.h>
32 #include <linux/string.h>
33 #include <linux/scatterlist.h>
34 
35 /* Offsets into SLCR regmap */
36 
37 /* FPGA Software Reset Control */
38 #define SLCR_FPGA_RST_CTRL_OFFSET	0x240
39 /* Level Shifters Enable */
40 #define SLCR_LVL_SHFTR_EN_OFFSET	0x900
41 
42 /* Constant Definitions */
43 
44 /* Control Register */
45 #define CTRL_OFFSET			0x00
46 /* Lock Register */
47 #define LOCK_OFFSET			0x04
48 /* Interrupt Status Register */
49 #define INT_STS_OFFSET			0x0c
50 /* Interrupt Mask Register */
51 #define INT_MASK_OFFSET			0x10
52 /* Status Register */
53 #define STATUS_OFFSET			0x14
54 /* DMA Source Address Register */
55 #define DMA_SRC_ADDR_OFFSET		0x18
56 /* DMA Destination Address Reg */
57 #define DMA_DST_ADDR_OFFSET		0x1c
58 /* DMA Source Transfer Length */
59 #define DMA_SRC_LEN_OFFSET		0x20
60 /* DMA Destination Transfer */
61 #define DMA_DEST_LEN_OFFSET		0x24
62 /* Unlock Register */
63 #define UNLOCK_OFFSET			0x34
64 /* Misc. Control Register */
65 #define MCTRL_OFFSET			0x80
66 
67 /* Control Register Bit definitions */
68 
69 /* Signal to reset FPGA */
70 #define CTRL_PCFG_PROG_B_MASK		BIT(30)
71 /* Enable PCAP for PR */
72 #define CTRL_PCAP_PR_MASK		BIT(27)
73 /* Enable PCAP */
74 #define CTRL_PCAP_MODE_MASK		BIT(26)
75 /* Lower rate to allow decrypt on the fly */
76 #define CTRL_PCAP_RATE_EN_MASK		BIT(25)
77 /* System booted in secure mode */
78 #define CTRL_SEC_EN_MASK		BIT(7)
79 
80 /* Miscellaneous Control Register bit definitions */
81 /* Internal PCAP loopback */
82 #define MCTRL_PCAP_LPBK_MASK		BIT(4)
83 
84 /* Status register bit definitions */
85 
86 /* FPGA init status */
87 #define STATUS_DMA_Q_F			BIT(31)
88 #define STATUS_DMA_Q_E			BIT(30)
89 #define STATUS_PCFG_INIT_MASK		BIT(4)
90 
91 /* Interrupt Status/Mask Register Bit definitions */
92 /* DMA command done */
93 #define IXR_DMA_DONE_MASK		BIT(13)
94 /* DMA and PCAP cmd done */
95 #define IXR_D_P_DONE_MASK		BIT(12)
96  /* FPGA programmed */
97 #define IXR_PCFG_DONE_MASK		BIT(2)
98 #define IXR_ERROR_FLAGS_MASK		0x00F0C860
99 #define IXR_ALL_MASK			0xF8F7F87F
100 
101 /* Miscellaneous constant values */
102 
103 /* Invalid DMA addr */
104 #define DMA_INVALID_ADDRESS		GENMASK(31, 0)
105 /* Used to unlock the dev */
106 #define UNLOCK_MASK			0x757bdf0d
107 /* Timeout for polling reset bits */
108 #define INIT_POLL_TIMEOUT		2500000
109 /* Delay for polling reset bits */
110 #define INIT_POLL_DELAY			20
111 /* Signal this is the last DMA transfer, wait for the AXI and PCAP before
112  * interrupting
113  */
114 #define DMA_SRC_LAST_TRANSFER		1
115 /* Timeout for DMA completion */
116 #define DMA_TIMEOUT_MS			5000
117 
118 /* Masks for controlling stuff in SLCR */
119 /* Disable all Level shifters */
120 #define LVL_SHFTR_DISABLE_ALL_MASK	0x0
121 /* Enable Level shifters from PS to PL */
122 #define LVL_SHFTR_ENABLE_PS_TO_PL	0xa
123 /* Enable Level shifters from PL to PS */
124 #define LVL_SHFTR_ENABLE_PL_TO_PS	0xf
125 /* Enable global resets */
126 #define FPGA_RST_ALL_MASK		0xf
127 /* Disable global resets */
128 #define FPGA_RST_NONE_MASK		0x0
129 
130 struct zynq_fpga_priv {
131 	int irq;
132 	struct clk *clk;
133 
134 	void __iomem *io_base;
135 	struct regmap *slcr;
136 
137 	spinlock_t dma_lock;
138 	unsigned int dma_elm;
139 	unsigned int dma_nelms;
140 	struct scatterlist *cur_sg;
141 
142 	struct completion dma_done;
143 };
144 
145 static inline void zynq_fpga_write(struct zynq_fpga_priv *priv, u32 offset,
146 				   u32 val)
147 {
148 	writel(val, priv->io_base + offset);
149 }
150 
151 static inline u32 zynq_fpga_read(const struct zynq_fpga_priv *priv,
152 				 u32 offset)
153 {
154 	return readl(priv->io_base + offset);
155 }
156 
157 #define zynq_fpga_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
158 	readl_poll_timeout(priv->io_base + addr, val, cond, sleep_us, \
159 			   timeout_us)
160 
161 /* Cause the specified irq mask bits to generate IRQs */
162 static inline void zynq_fpga_set_irq(struct zynq_fpga_priv *priv, u32 enable)
163 {
164 	zynq_fpga_write(priv, INT_MASK_OFFSET, ~enable);
165 }
166 
167 /* Must be called with dma_lock held */
168 static void zynq_step_dma(struct zynq_fpga_priv *priv)
169 {
170 	u32 addr;
171 	u32 len;
172 	bool first;
173 
174 	first = priv->dma_elm == 0;
175 	while (priv->cur_sg) {
176 		/* Feed the DMA queue until it is full. */
177 		if (zynq_fpga_read(priv, STATUS_OFFSET) & STATUS_DMA_Q_F)
178 			break;
179 
180 		addr = sg_dma_address(priv->cur_sg);
181 		len = sg_dma_len(priv->cur_sg);
182 		if (priv->dma_elm + 1 == priv->dma_nelms) {
183 			/* The last transfer waits for the PCAP to finish too,
184 			 * notice this also changes the irq_mask to ignore
185 			 * IXR_DMA_DONE_MASK which ensures we do not trigger
186 			 * the completion too early.
187 			 */
188 			addr |= DMA_SRC_LAST_TRANSFER;
189 			priv->cur_sg = NULL;
190 		} else {
191 			priv->cur_sg = sg_next(priv->cur_sg);
192 			priv->dma_elm++;
193 		}
194 
195 		zynq_fpga_write(priv, DMA_SRC_ADDR_OFFSET, addr);
196 		zynq_fpga_write(priv, DMA_DST_ADDR_OFFSET, DMA_INVALID_ADDRESS);
197 		zynq_fpga_write(priv, DMA_SRC_LEN_OFFSET, len / 4);
198 		zynq_fpga_write(priv, DMA_DEST_LEN_OFFSET, 0);
199 	}
200 
201 	/* Once the first transfer is queued we can turn on the ISR, future
202 	 * calls to zynq_step_dma will happen from the ISR context. The
203 	 * dma_lock spinlock guarentees this handover is done coherently, the
204 	 * ISR enable is put at the end to avoid another CPU spinning in the
205 	 * ISR on this lock.
206 	 */
207 	if (first && priv->cur_sg) {
208 		zynq_fpga_set_irq(priv,
209 				  IXR_DMA_DONE_MASK | IXR_ERROR_FLAGS_MASK);
210 	} else if (!priv->cur_sg) {
211 		/* The last transfer changes to DMA & PCAP mode since we do
212 		 * not want to continue until everything has been flushed into
213 		 * the PCAP.
214 		 */
215 		zynq_fpga_set_irq(priv,
216 				  IXR_D_P_DONE_MASK | IXR_ERROR_FLAGS_MASK);
217 	}
218 }
219 
220 static irqreturn_t zynq_fpga_isr(int irq, void *data)
221 {
222 	struct zynq_fpga_priv *priv = data;
223 	u32 intr_status;
224 
225 	/* If anything other than DMA completion is reported stop and hand
226 	 * control back to zynq_fpga_ops_write, something went wrong,
227 	 * otherwise progress the DMA.
228 	 */
229 	spin_lock(&priv->dma_lock);
230 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
231 	if (!(intr_status & IXR_ERROR_FLAGS_MASK) &&
232 	    (intr_status & IXR_DMA_DONE_MASK) && priv->cur_sg) {
233 		zynq_fpga_write(priv, INT_STS_OFFSET, IXR_DMA_DONE_MASK);
234 		zynq_step_dma(priv);
235 		spin_unlock(&priv->dma_lock);
236 		return IRQ_HANDLED;
237 	}
238 	spin_unlock(&priv->dma_lock);
239 
240 	zynq_fpga_set_irq(priv, 0);
241 	complete(&priv->dma_done);
242 
243 	return IRQ_HANDLED;
244 }
245 
246 /* Sanity check the proposed bitstream. It must start with the sync word in
247  * the correct byte order, and be dword aligned. The input is a Xilinx .bin
248  * file with every 32 bit quantity swapped.
249  */
250 static bool zynq_fpga_has_sync(const u8 *buf, size_t count)
251 {
252 	for (; count >= 4; buf += 4, count -= 4)
253 		if (buf[0] == 0x66 && buf[1] == 0x55 && buf[2] == 0x99 &&
254 		    buf[3] == 0xaa)
255 			return true;
256 	return false;
257 }
258 
259 static int zynq_fpga_ops_write_init(struct fpga_manager *mgr,
260 				    struct fpga_image_info *info,
261 				    const char *buf, size_t count)
262 {
263 	struct zynq_fpga_priv *priv;
264 	u32 ctrl, status;
265 	int err;
266 
267 	priv = mgr->priv;
268 
269 	err = clk_enable(priv->clk);
270 	if (err)
271 		return err;
272 
273 	/* check if bitstream is encrypted & and system's still secure */
274 	if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM) {
275 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
276 		if (!(ctrl & CTRL_SEC_EN_MASK)) {
277 			dev_err(&mgr->dev,
278 				"System not secure, can't use crypted bitstreams\n");
279 			err = -EINVAL;
280 			goto out_err;
281 		}
282 	}
283 
284 	/* don't globally reset PL if we're doing partial reconfig */
285 	if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
286 		if (!zynq_fpga_has_sync(buf, count)) {
287 			dev_err(&mgr->dev,
288 				"Invalid bitstream, could not find a sync word. Bitstream must be a byte swapped .bin file\n");
289 			err = -EINVAL;
290 			goto out_err;
291 		}
292 
293 		/* assert AXI interface resets */
294 		regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
295 			     FPGA_RST_ALL_MASK);
296 
297 		/* disable all level shifters */
298 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
299 			     LVL_SHFTR_DISABLE_ALL_MASK);
300 		/* enable level shifters from PS to PL */
301 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
302 			     LVL_SHFTR_ENABLE_PS_TO_PL);
303 
304 		/* create a rising edge on PCFG_INIT. PCFG_INIT follows
305 		 * PCFG_PROG_B, so we need to poll it after setting PCFG_PROG_B
306 		 * to make sure the rising edge actually happens.
307 		 * Note: PCFG_PROG_B is low active, sequence as described in
308 		 * UG585 v1.10 page 211
309 		 */
310 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
311 		ctrl |= CTRL_PCFG_PROG_B_MASK;
312 
313 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
314 
315 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
316 					     status & STATUS_PCFG_INIT_MASK,
317 					     INIT_POLL_DELAY,
318 					     INIT_POLL_TIMEOUT);
319 		if (err) {
320 			dev_err(&mgr->dev, "Timeout waiting for PCFG_INIT\n");
321 			goto out_err;
322 		}
323 
324 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
325 		ctrl &= ~CTRL_PCFG_PROG_B_MASK;
326 
327 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
328 
329 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
330 					     !(status & STATUS_PCFG_INIT_MASK),
331 					     INIT_POLL_DELAY,
332 					     INIT_POLL_TIMEOUT);
333 		if (err) {
334 			dev_err(&mgr->dev, "Timeout waiting for !PCFG_INIT\n");
335 			goto out_err;
336 		}
337 
338 		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
339 		ctrl |= CTRL_PCFG_PROG_B_MASK;
340 
341 		zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
342 
343 		err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
344 					     status & STATUS_PCFG_INIT_MASK,
345 					     INIT_POLL_DELAY,
346 					     INIT_POLL_TIMEOUT);
347 		if (err) {
348 			dev_err(&mgr->dev, "Timeout waiting for PCFG_INIT\n");
349 			goto out_err;
350 		}
351 	}
352 
353 	/* set configuration register with following options:
354 	 * - enable PCAP interface
355 	 * - set throughput for maximum speed (if bistream not crypted)
356 	 * - set CPU in user mode
357 	 */
358 	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
359 	if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM)
360 		zynq_fpga_write(priv, CTRL_OFFSET,
361 				(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
362 				 | CTRL_PCAP_RATE_EN_MASK | ctrl));
363 	else
364 		zynq_fpga_write(priv, CTRL_OFFSET,
365 				(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
366 				 | ctrl));
367 
368 
369 	/* We expect that the command queue is empty right now. */
370 	status = zynq_fpga_read(priv, STATUS_OFFSET);
371 	if ((status & STATUS_DMA_Q_F) ||
372 	    (status & STATUS_DMA_Q_E) != STATUS_DMA_Q_E) {
373 		dev_err(&mgr->dev, "DMA command queue not right\n");
374 		err = -EBUSY;
375 		goto out_err;
376 	}
377 
378 	/* ensure internal PCAP loopback is disabled */
379 	ctrl = zynq_fpga_read(priv, MCTRL_OFFSET);
380 	zynq_fpga_write(priv, MCTRL_OFFSET, (~MCTRL_PCAP_LPBK_MASK & ctrl));
381 
382 	clk_disable(priv->clk);
383 
384 	return 0;
385 
386 out_err:
387 	clk_disable(priv->clk);
388 
389 	return err;
390 }
391 
392 static int zynq_fpga_ops_write(struct fpga_manager *mgr, struct sg_table *sgt)
393 {
394 	struct zynq_fpga_priv *priv;
395 	const char *why;
396 	int err;
397 	u32 intr_status;
398 	unsigned long timeout;
399 	unsigned long flags;
400 	struct scatterlist *sg;
401 	int i;
402 
403 	priv = mgr->priv;
404 
405 	/* The hardware can only DMA multiples of 4 bytes, and it requires the
406 	 * starting addresses to be aligned to 64 bits (UG585 pg 212).
407 	 */
408 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
409 		if ((sg->offset % 8) || (sg->length % 4)) {
410 			dev_err(&mgr->dev,
411 			    "Invalid bitstream, chunks must be aligned\n");
412 			return -EINVAL;
413 		}
414 	}
415 
416 	priv->dma_nelms =
417 	    dma_map_sg(mgr->dev.parent, sgt->sgl, sgt->nents, DMA_TO_DEVICE);
418 	if (priv->dma_nelms == 0) {
419 		dev_err(&mgr->dev, "Unable to DMA map (TO_DEVICE)\n");
420 		return -ENOMEM;
421 	}
422 
423 	/* enable clock */
424 	err = clk_enable(priv->clk);
425 	if (err)
426 		goto out_free;
427 
428 	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
429 	reinit_completion(&priv->dma_done);
430 
431 	/* zynq_step_dma will turn on interrupts */
432 	spin_lock_irqsave(&priv->dma_lock, flags);
433 	priv->dma_elm = 0;
434 	priv->cur_sg = sgt->sgl;
435 	zynq_step_dma(priv);
436 	spin_unlock_irqrestore(&priv->dma_lock, flags);
437 
438 	timeout = wait_for_completion_timeout(&priv->dma_done,
439 					      msecs_to_jiffies(DMA_TIMEOUT_MS));
440 
441 	spin_lock_irqsave(&priv->dma_lock, flags);
442 	zynq_fpga_set_irq(priv, 0);
443 	priv->cur_sg = NULL;
444 	spin_unlock_irqrestore(&priv->dma_lock, flags);
445 
446 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
447 	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
448 
449 	/* There doesn't seem to be a way to force cancel any DMA, so if
450 	 * something went wrong we are relying on the hardware to have halted
451 	 * the DMA before we get here, if there was we could use
452 	 * wait_for_completion_interruptible too.
453 	 */
454 
455 	if (intr_status & IXR_ERROR_FLAGS_MASK) {
456 		why = "DMA reported error";
457 		err = -EIO;
458 		goto out_report;
459 	}
460 
461 	if (priv->cur_sg ||
462 	    !((intr_status & IXR_D_P_DONE_MASK) == IXR_D_P_DONE_MASK)) {
463 		if (timeout == 0)
464 			why = "DMA timed out";
465 		else
466 			why = "DMA did not complete";
467 		err = -EIO;
468 		goto out_report;
469 	}
470 
471 	err = 0;
472 	goto out_clk;
473 
474 out_report:
475 	dev_err(&mgr->dev,
476 		"%s: INT_STS:0x%x CTRL:0x%x LOCK:0x%x INT_MASK:0x%x STATUS:0x%x MCTRL:0x%x\n",
477 		why,
478 		intr_status,
479 		zynq_fpga_read(priv, CTRL_OFFSET),
480 		zynq_fpga_read(priv, LOCK_OFFSET),
481 		zynq_fpga_read(priv, INT_MASK_OFFSET),
482 		zynq_fpga_read(priv, STATUS_OFFSET),
483 		zynq_fpga_read(priv, MCTRL_OFFSET));
484 
485 out_clk:
486 	clk_disable(priv->clk);
487 
488 out_free:
489 	dma_unmap_sg(mgr->dev.parent, sgt->sgl, sgt->nents, DMA_TO_DEVICE);
490 	return err;
491 }
492 
493 static int zynq_fpga_ops_write_complete(struct fpga_manager *mgr,
494 					struct fpga_image_info *info)
495 {
496 	struct zynq_fpga_priv *priv = mgr->priv;
497 	int err;
498 	u32 intr_status;
499 
500 	err = clk_enable(priv->clk);
501 	if (err)
502 		return err;
503 
504 	err = zynq_fpga_poll_timeout(priv, INT_STS_OFFSET, intr_status,
505 				     intr_status & IXR_PCFG_DONE_MASK,
506 				     INIT_POLL_DELAY,
507 				     INIT_POLL_TIMEOUT);
508 
509 	clk_disable(priv->clk);
510 
511 	if (err)
512 		return err;
513 
514 	/* for the partial reconfig case we didn't touch the level shifters */
515 	if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
516 		/* enable level shifters from PL to PS */
517 		regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
518 			     LVL_SHFTR_ENABLE_PL_TO_PS);
519 
520 		/* deassert AXI interface resets */
521 		regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
522 			     FPGA_RST_NONE_MASK);
523 	}
524 
525 	return 0;
526 }
527 
528 static enum fpga_mgr_states zynq_fpga_ops_state(struct fpga_manager *mgr)
529 {
530 	int err;
531 	u32 intr_status;
532 	struct zynq_fpga_priv *priv;
533 
534 	priv = mgr->priv;
535 
536 	err = clk_enable(priv->clk);
537 	if (err)
538 		return FPGA_MGR_STATE_UNKNOWN;
539 
540 	intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
541 	clk_disable(priv->clk);
542 
543 	if (intr_status & IXR_PCFG_DONE_MASK)
544 		return FPGA_MGR_STATE_OPERATING;
545 
546 	return FPGA_MGR_STATE_UNKNOWN;
547 }
548 
549 static const struct fpga_manager_ops zynq_fpga_ops = {
550 	.initial_header_size = 128,
551 	.state = zynq_fpga_ops_state,
552 	.write_init = zynq_fpga_ops_write_init,
553 	.write_sg = zynq_fpga_ops_write,
554 	.write_complete = zynq_fpga_ops_write_complete,
555 };
556 
557 static int zynq_fpga_probe(struct platform_device *pdev)
558 {
559 	struct device *dev = &pdev->dev;
560 	struct zynq_fpga_priv *priv;
561 	struct resource *res;
562 	int err;
563 
564 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
565 	if (!priv)
566 		return -ENOMEM;
567 	spin_lock_init(&priv->dma_lock);
568 
569 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
570 	priv->io_base = devm_ioremap_resource(dev, res);
571 	if (IS_ERR(priv->io_base))
572 		return PTR_ERR(priv->io_base);
573 
574 	priv->slcr = syscon_regmap_lookup_by_phandle(dev->of_node,
575 		"syscon");
576 	if (IS_ERR(priv->slcr)) {
577 		dev_err(dev, "unable to get zynq-slcr regmap\n");
578 		return PTR_ERR(priv->slcr);
579 	}
580 
581 	init_completion(&priv->dma_done);
582 
583 	priv->irq = platform_get_irq(pdev, 0);
584 	if (priv->irq < 0) {
585 		dev_err(dev, "No IRQ available\n");
586 		return priv->irq;
587 	}
588 
589 	priv->clk = devm_clk_get(dev, "ref_clk");
590 	if (IS_ERR(priv->clk)) {
591 		dev_err(dev, "input clock not found\n");
592 		return PTR_ERR(priv->clk);
593 	}
594 
595 	err = clk_prepare_enable(priv->clk);
596 	if (err) {
597 		dev_err(dev, "unable to enable clock\n");
598 		return err;
599 	}
600 
601 	/* unlock the device */
602 	zynq_fpga_write(priv, UNLOCK_OFFSET, UNLOCK_MASK);
603 
604 	zynq_fpga_set_irq(priv, 0);
605 	zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
606 	err = devm_request_irq(dev, priv->irq, zynq_fpga_isr, 0, dev_name(dev),
607 			       priv);
608 	if (err) {
609 		dev_err(dev, "unable to request IRQ\n");
610 		clk_disable_unprepare(priv->clk);
611 		return err;
612 	}
613 
614 	clk_disable(priv->clk);
615 
616 	err = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
617 				&zynq_fpga_ops, priv);
618 	if (err) {
619 		dev_err(dev, "unable to register FPGA manager\n");
620 		clk_unprepare(priv->clk);
621 		return err;
622 	}
623 
624 	return 0;
625 }
626 
627 static int zynq_fpga_remove(struct platform_device *pdev)
628 {
629 	struct zynq_fpga_priv *priv;
630 	struct fpga_manager *mgr;
631 
632 	mgr = platform_get_drvdata(pdev);
633 	priv = mgr->priv;
634 
635 	fpga_mgr_unregister(&pdev->dev);
636 
637 	clk_unprepare(priv->clk);
638 
639 	return 0;
640 }
641 
642 #ifdef CONFIG_OF
643 static const struct of_device_id zynq_fpga_of_match[] = {
644 	{ .compatible = "xlnx,zynq-devcfg-1.0", },
645 	{},
646 };
647 
648 MODULE_DEVICE_TABLE(of, zynq_fpga_of_match);
649 #endif
650 
651 static struct platform_driver zynq_fpga_driver = {
652 	.probe = zynq_fpga_probe,
653 	.remove = zynq_fpga_remove,
654 	.driver = {
655 		.name = "zynq_fpga_manager",
656 		.of_match_table = of_match_ptr(zynq_fpga_of_match),
657 	},
658 };
659 
660 module_platform_driver(zynq_fpga_driver);
661 
662 MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
663 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
664 MODULE_DESCRIPTION("Xilinx Zynq FPGA Manager");
665 MODULE_LICENSE("GPL v2");
666