xref: /openbmc/linux/drivers/fpga/altera-cvp.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * FPGA Manager Driver for Altera Arria/Cyclone/Stratix CvP
4  *
5  * Copyright (C) 2017 DENX Software Engineering
6  *
7  * Anatolij Gustschin <agust@denx.de>
8  *
9  * Manage Altera FPGA firmware using PCIe CvP.
10  * Firmware must be in binary "rbf" format.
11  */
12 
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/fpga/fpga-mgr.h>
16 #include <linux/module.h>
17 #include <linux/pci.h>
18 #include <linux/sizes.h>
19 
20 #define CVP_BAR		0	/* BAR used for data transfer in memory mode */
21 #define CVP_DUMMY_WR	244	/* dummy writes to clear CvP state machine */
22 #define TIMEOUT_US	2000	/* CVP STATUS timeout for USERMODE polling */
23 
24 /* Vendor Specific Extended Capability Registers */
25 #define VSE_PCIE_EXT_CAP_ID		0x0
26 #define VSE_PCIE_EXT_CAP_ID_VAL		0x000b	/* 16bit */
27 
28 #define VSE_CVP_STATUS			0x1c	/* 32bit */
29 #define VSE_CVP_STATUS_CFG_RDY		BIT(18)	/* CVP_CONFIG_READY */
30 #define VSE_CVP_STATUS_CFG_ERR		BIT(19)	/* CVP_CONFIG_ERROR */
31 #define VSE_CVP_STATUS_CVP_EN		BIT(20)	/* ctrl block is enabling CVP */
32 #define VSE_CVP_STATUS_USERMODE		BIT(21)	/* USERMODE */
33 #define VSE_CVP_STATUS_CFG_DONE		BIT(23)	/* CVP_CONFIG_DONE */
34 #define VSE_CVP_STATUS_PLD_CLK_IN_USE	BIT(24)	/* PLD_CLK_IN_USE */
35 
36 #define VSE_CVP_MODE_CTRL		0x20	/* 32bit */
37 #define VSE_CVP_MODE_CTRL_CVP_MODE	BIT(0)	/* CVP (1) or normal mode (0) */
38 #define VSE_CVP_MODE_CTRL_HIP_CLK_SEL	BIT(1) /* PMA (1) or fabric clock (0) */
39 #define VSE_CVP_MODE_CTRL_NUMCLKS_OFF	8	/* NUMCLKS bits offset */
40 #define VSE_CVP_MODE_CTRL_NUMCLKS_MASK	GENMASK(15, 8)
41 
42 #define VSE_CVP_DATA			0x28	/* 32bit */
43 #define VSE_CVP_PROG_CTRL		0x2c	/* 32bit */
44 #define VSE_CVP_PROG_CTRL_CONFIG	BIT(0)
45 #define VSE_CVP_PROG_CTRL_START_XFER	BIT(1)
46 #define VSE_CVP_PROG_CTRL_MASK		GENMASK(1, 0)
47 
48 #define VSE_UNCOR_ERR_STATUS		0x34	/* 32bit */
49 #define VSE_UNCOR_ERR_CVP_CFG_ERR	BIT(5)	/* CVP_CONFIG_ERROR_LATCHED */
50 
51 #define V1_VSEC_OFFSET			0x200	/* Vendor Specific Offset V1 */
52 /* V2 Defines */
53 #define VSE_CVP_TX_CREDITS		0x49	/* 8bit */
54 
55 #define V2_CREDIT_TIMEOUT_US		20000
56 #define V2_CHECK_CREDIT_US		10
57 #define V2_POLL_TIMEOUT_US		1000000
58 #define V2_USER_TIMEOUT_US		500000
59 
60 #define V1_POLL_TIMEOUT_US		10
61 
62 #define DRV_NAME		"altera-cvp"
63 #define ALTERA_CVP_MGR_NAME	"Altera CvP FPGA Manager"
64 
65 /* Write block sizes */
66 #define ALTERA_CVP_V1_SIZE	4
67 #define ALTERA_CVP_V2_SIZE	4096
68 
69 /* Optional CvP config error status check for debugging */
70 static bool altera_cvp_chkcfg;
71 
72 struct cvp_priv;
73 
74 struct altera_cvp_conf {
75 	struct fpga_manager	*mgr;
76 	struct pci_dev		*pci_dev;
77 	void __iomem		*map;
78 	void			(*write_data)(struct altera_cvp_conf *conf,
79 					      u32 data);
80 	char			mgr_name[64];
81 	u8			numclks;
82 	u32			sent_packets;
83 	u32			vsec_offset;
84 	const struct cvp_priv	*priv;
85 };
86 
87 struct cvp_priv {
88 	void	(*switch_clk)(struct altera_cvp_conf *conf);
89 	int	(*clear_state)(struct altera_cvp_conf *conf);
90 	int	(*wait_credit)(struct fpga_manager *mgr, u32 blocks);
91 	size_t	block_size;
92 	int	poll_time_us;
93 	int	user_time_us;
94 };
95 
96 static int altera_read_config_byte(struct altera_cvp_conf *conf,
97 				   int where, u8 *val)
98 {
99 	return pci_read_config_byte(conf->pci_dev, conf->vsec_offset + where,
100 				    val);
101 }
102 
103 static int altera_read_config_dword(struct altera_cvp_conf *conf,
104 				    int where, u32 *val)
105 {
106 	return pci_read_config_dword(conf->pci_dev, conf->vsec_offset + where,
107 				     val);
108 }
109 
110 static int altera_write_config_dword(struct altera_cvp_conf *conf,
111 				     int where, u32 val)
112 {
113 	return pci_write_config_dword(conf->pci_dev, conf->vsec_offset + where,
114 				      val);
115 }
116 
117 static enum fpga_mgr_states altera_cvp_state(struct fpga_manager *mgr)
118 {
119 	struct altera_cvp_conf *conf = mgr->priv;
120 	u32 status;
121 
122 	altera_read_config_dword(conf, VSE_CVP_STATUS, &status);
123 
124 	if (status & VSE_CVP_STATUS_CFG_DONE)
125 		return FPGA_MGR_STATE_OPERATING;
126 
127 	if (status & VSE_CVP_STATUS_CVP_EN)
128 		return FPGA_MGR_STATE_POWER_UP;
129 
130 	return FPGA_MGR_STATE_UNKNOWN;
131 }
132 
133 static void altera_cvp_write_data_iomem(struct altera_cvp_conf *conf, u32 val)
134 {
135 	writel(val, conf->map);
136 }
137 
138 static void altera_cvp_write_data_config(struct altera_cvp_conf *conf, u32 val)
139 {
140 	pci_write_config_dword(conf->pci_dev, conf->vsec_offset + VSE_CVP_DATA,
141 			       val);
142 }
143 
144 /* switches between CvP clock and internal clock */
145 static void altera_cvp_dummy_write(struct altera_cvp_conf *conf)
146 {
147 	unsigned int i;
148 	u32 val;
149 
150 	/* set 1 CVP clock cycle for every CVP Data Register Write */
151 	altera_read_config_dword(conf, VSE_CVP_MODE_CTRL, &val);
152 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
153 	val |= 1 << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
154 	altera_write_config_dword(conf, VSE_CVP_MODE_CTRL, val);
155 
156 	for (i = 0; i < CVP_DUMMY_WR; i++)
157 		conf->write_data(conf, 0); /* dummy data, could be any value */
158 }
159 
160 static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
161 				  u32 status_val, int timeout_us)
162 {
163 	unsigned int retries;
164 	u32 val;
165 
166 	retries = timeout_us / 10;
167 	if (timeout_us % 10)
168 		retries++;
169 
170 	do {
171 		altera_read_config_dword(conf, VSE_CVP_STATUS, &val);
172 		if ((val & status_mask) == status_val)
173 			return 0;
174 
175 		/* use small usleep value to re-check and break early */
176 		usleep_range(10, 11);
177 	} while (--retries);
178 
179 	return -ETIMEDOUT;
180 }
181 
182 static int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
183 {
184 	struct altera_cvp_conf *conf = mgr->priv;
185 	u32 val;
186 	int ret;
187 
188 	/* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
189 	ret = altera_read_config_dword(conf, VSE_CVP_STATUS, &val);
190 	if (ret || (val & VSE_CVP_STATUS_CFG_ERR)) {
191 		dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
192 			bytes);
193 		return -EPROTO;
194 	}
195 	return 0;
196 }
197 
198 /*
199  * CvP Version2 Functions
200  * Recent Intel FPGAs use a credit mechanism to throttle incoming
201  * bitstreams and a different method of clearing the state.
202  */
203 
204 static int altera_cvp_v2_clear_state(struct altera_cvp_conf *conf)
205 {
206 	u32 val;
207 	int ret;
208 
209 	/* Clear the START_XFER and CVP_CONFIG bits */
210 	ret = altera_read_config_dword(conf, VSE_CVP_PROG_CTRL, &val);
211 	if (ret) {
212 		dev_err(&conf->pci_dev->dev,
213 			"Error reading CVP Program Control Register\n");
214 		return ret;
215 	}
216 
217 	val &= ~VSE_CVP_PROG_CTRL_MASK;
218 	ret = altera_write_config_dword(conf, VSE_CVP_PROG_CTRL, val);
219 	if (ret) {
220 		dev_err(&conf->pci_dev->dev,
221 			"Error writing CVP Program Control Register\n");
222 		return ret;
223 	}
224 
225 	return altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0,
226 				      conf->priv->poll_time_us);
227 }
228 
229 static int altera_cvp_v2_wait_for_credit(struct fpga_manager *mgr,
230 					 u32 blocks)
231 {
232 	u32 timeout = V2_CREDIT_TIMEOUT_US / V2_CHECK_CREDIT_US;
233 	struct altera_cvp_conf *conf = mgr->priv;
234 	int ret;
235 	u8 val;
236 
237 	do {
238 		ret = altera_read_config_byte(conf, VSE_CVP_TX_CREDITS, &val);
239 		if (ret) {
240 			dev_err(&conf->pci_dev->dev,
241 				"Error reading CVP Credit Register\n");
242 			return ret;
243 		}
244 
245 		/* Return if there is space in FIFO */
246 		if (val - (u8)conf->sent_packets)
247 			return 0;
248 
249 		ret = altera_cvp_chk_error(mgr, blocks * ALTERA_CVP_V2_SIZE);
250 		if (ret) {
251 			dev_err(&conf->pci_dev->dev,
252 				"CE Bit error credit reg[0x%x]:sent[0x%x]\n",
253 				val, conf->sent_packets);
254 			return -EAGAIN;
255 		}
256 
257 		/* Limit the check credit byte traffic */
258 		usleep_range(V2_CHECK_CREDIT_US, V2_CHECK_CREDIT_US + 1);
259 	} while (timeout--);
260 
261 	dev_err(&conf->pci_dev->dev, "Timeout waiting for credit\n");
262 	return -ETIMEDOUT;
263 }
264 
265 static int altera_cvp_send_block(struct altera_cvp_conf *conf,
266 				 const u32 *data, size_t len)
267 {
268 	u32 mask, words = len / sizeof(u32);
269 	int i, remainder;
270 
271 	for (i = 0; i < words; i++)
272 		conf->write_data(conf, *data++);
273 
274 	/* write up to 3 trailing bytes, if any */
275 	remainder = len % sizeof(u32);
276 	if (remainder) {
277 		mask = BIT(remainder * 8) - 1;
278 		if (mask)
279 			conf->write_data(conf, *data & mask);
280 	}
281 
282 	return 0;
283 }
284 
285 static int altera_cvp_teardown(struct fpga_manager *mgr,
286 			       struct fpga_image_info *info)
287 {
288 	struct altera_cvp_conf *conf = mgr->priv;
289 	int ret;
290 	u32 val;
291 
292 	/* STEP 12 - reset START_XFER bit */
293 	altera_read_config_dword(conf, VSE_CVP_PROG_CTRL, &val);
294 	val &= ~VSE_CVP_PROG_CTRL_START_XFER;
295 	altera_write_config_dword(conf, VSE_CVP_PROG_CTRL, val);
296 
297 	/* STEP 13 - reset CVP_CONFIG bit */
298 	val &= ~VSE_CVP_PROG_CTRL_CONFIG;
299 	altera_write_config_dword(conf, VSE_CVP_PROG_CTRL, val);
300 
301 	/*
302 	 * STEP 14
303 	 * - set CVP_NUMCLKS to 1 and then issue CVP_DUMMY_WR dummy
304 	 *   writes to the HIP
305 	 */
306 	if (conf->priv->switch_clk)
307 		conf->priv->switch_clk(conf);
308 
309 	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
310 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0,
311 				     conf->priv->poll_time_us);
312 	if (ret)
313 		dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");
314 
315 	return ret;
316 }
317 
318 static int altera_cvp_write_init(struct fpga_manager *mgr,
319 				 struct fpga_image_info *info,
320 				 const char *buf, size_t count)
321 {
322 	struct altera_cvp_conf *conf = mgr->priv;
323 	u32 iflags, val;
324 	int ret;
325 
326 	iflags = info ? info->flags : 0;
327 
328 	if (iflags & FPGA_MGR_PARTIAL_RECONFIG) {
329 		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
330 		return -EINVAL;
331 	}
332 
333 	/* Determine allowed clock to data ratio */
334 	if (iflags & FPGA_MGR_COMPRESSED_BITSTREAM)
335 		conf->numclks = 8; /* ratio for all compressed images */
336 	else if (iflags & FPGA_MGR_ENCRYPTED_BITSTREAM)
337 		conf->numclks = 4; /* for uncompressed and encrypted images */
338 	else
339 		conf->numclks = 1; /* for uncompressed and unencrypted images */
340 
341 	/* STEP 1 - read CVP status and check CVP_EN flag */
342 	altera_read_config_dword(conf, VSE_CVP_STATUS, &val);
343 	if (!(val & VSE_CVP_STATUS_CVP_EN)) {
344 		dev_err(&mgr->dev, "CVP mode off: 0x%04x\n", val);
345 		return -ENODEV;
346 	}
347 
348 	if (val & VSE_CVP_STATUS_CFG_RDY) {
349 		dev_warn(&mgr->dev, "CvP already started, teardown first\n");
350 		ret = altera_cvp_teardown(mgr, info);
351 		if (ret)
352 			return ret;
353 	}
354 
355 	/*
356 	 * STEP 2
357 	 * - set HIP_CLK_SEL and CVP_MODE (must be set in the order mentioned)
358 	 */
359 	/* switch from fabric to PMA clock */
360 	altera_read_config_dword(conf, VSE_CVP_MODE_CTRL, &val);
361 	val |= VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
362 	altera_write_config_dword(conf, VSE_CVP_MODE_CTRL, val);
363 
364 	/* set CVP mode */
365 	altera_read_config_dword(conf, VSE_CVP_MODE_CTRL, &val);
366 	val |= VSE_CVP_MODE_CTRL_CVP_MODE;
367 	altera_write_config_dword(conf, VSE_CVP_MODE_CTRL, val);
368 
369 	/*
370 	 * STEP 3
371 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
372 	 */
373 	if (conf->priv->switch_clk)
374 		conf->priv->switch_clk(conf);
375 
376 	if (conf->priv->clear_state) {
377 		ret = conf->priv->clear_state(conf);
378 		if (ret) {
379 			dev_err(&mgr->dev, "Problem clearing out state\n");
380 			return ret;
381 		}
382 	}
383 
384 	conf->sent_packets = 0;
385 
386 	/* STEP 4 - set CVP_CONFIG bit */
387 	altera_read_config_dword(conf, VSE_CVP_PROG_CTRL, &val);
388 	/* request control block to begin transfer using CVP */
389 	val |= VSE_CVP_PROG_CTRL_CONFIG;
390 	altera_write_config_dword(conf, VSE_CVP_PROG_CTRL, val);
391 
392 	/* STEP 5 - poll CVP_CONFIG READY for 1 with timeout */
393 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY,
394 				     VSE_CVP_STATUS_CFG_RDY,
395 				     conf->priv->poll_time_us);
396 	if (ret) {
397 		dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
398 		return ret;
399 	}
400 
401 	/*
402 	 * STEP 6
403 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
404 	 */
405 	if (conf->priv->switch_clk)
406 		conf->priv->switch_clk(conf);
407 
408 	if (altera_cvp_chkcfg) {
409 		ret = altera_cvp_chk_error(mgr, 0);
410 		if (ret) {
411 			dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
412 			return ret;
413 		}
414 	}
415 
416 	/* STEP 7 - set START_XFER */
417 	altera_read_config_dword(conf, VSE_CVP_PROG_CTRL, &val);
418 	val |= VSE_CVP_PROG_CTRL_START_XFER;
419 	altera_write_config_dword(conf, VSE_CVP_PROG_CTRL, val);
420 
421 	/* STEP 8 - start transfer (set CVP_NUMCLKS for bitstream) */
422 	if (conf->priv->switch_clk) {
423 		altera_read_config_dword(conf, VSE_CVP_MODE_CTRL, &val);
424 		val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
425 		val |= conf->numclks << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
426 		altera_write_config_dword(conf, VSE_CVP_MODE_CTRL, val);
427 	}
428 	return 0;
429 }
430 
431 static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
432 			    size_t count)
433 {
434 	struct altera_cvp_conf *conf = mgr->priv;
435 	size_t done, remaining, len;
436 	const u32 *data;
437 	int status = 0;
438 
439 	/* STEP 9 - write 32-bit data from RBF file to CVP data register */
440 	data = (u32 *)buf;
441 	remaining = count;
442 	done = 0;
443 
444 	while (remaining) {
445 		/* Use credit throttling if available */
446 		if (conf->priv->wait_credit) {
447 			status = conf->priv->wait_credit(mgr, done);
448 			if (status) {
449 				dev_err(&conf->pci_dev->dev,
450 					"Wait Credit ERR: 0x%x\n", status);
451 				return status;
452 			}
453 		}
454 
455 		len = min(conf->priv->block_size, remaining);
456 		altera_cvp_send_block(conf, data, len);
457 		data += len / sizeof(u32);
458 		done += len;
459 		remaining -= len;
460 		conf->sent_packets++;
461 
462 		/*
463 		 * STEP 10 (optional) and STEP 11
464 		 * - check error flag
465 		 * - loop until data transfer completed
466 		 * Config images can be huge (more than 40 MiB), so
467 		 * only check after a new 4k data block has been written.
468 		 * This reduces the number of checks and speeds up the
469 		 * configuration process.
470 		 */
471 		if (altera_cvp_chkcfg && !(done % SZ_4K)) {
472 			status = altera_cvp_chk_error(mgr, done);
473 			if (status < 0)
474 				return status;
475 		}
476 	}
477 
478 	if (altera_cvp_chkcfg)
479 		status = altera_cvp_chk_error(mgr, count);
480 
481 	return status;
482 }
483 
484 static int altera_cvp_write_complete(struct fpga_manager *mgr,
485 				     struct fpga_image_info *info)
486 {
487 	struct altera_cvp_conf *conf = mgr->priv;
488 	u32 mask, val;
489 	int ret;
490 
491 	ret = altera_cvp_teardown(mgr, info);
492 	if (ret)
493 		return ret;
494 
495 	/* STEP 16 - check CVP_CONFIG_ERROR_LATCHED bit */
496 	altera_read_config_dword(conf, VSE_UNCOR_ERR_STATUS, &val);
497 	if (val & VSE_UNCOR_ERR_CVP_CFG_ERR) {
498 		dev_err(&mgr->dev, "detected CVP_CONFIG_ERROR_LATCHED!\n");
499 		return -EPROTO;
500 	}
501 
502 	/* STEP 17 - reset CVP_MODE and HIP_CLK_SEL bit */
503 	altera_read_config_dword(conf, VSE_CVP_MODE_CTRL, &val);
504 	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
505 	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
506 	altera_write_config_dword(conf, VSE_CVP_MODE_CTRL, val);
507 
508 	/* STEP 18 - poll PLD_CLK_IN_USE and USER_MODE bits */
509 	mask = VSE_CVP_STATUS_PLD_CLK_IN_USE | VSE_CVP_STATUS_USERMODE;
510 	ret = altera_cvp_wait_status(conf, mask, mask,
511 				     conf->priv->user_time_us);
512 	if (ret)
513 		dev_err(&mgr->dev, "PLD_CLK_IN_USE|USERMODE timeout\n");
514 
515 	return ret;
516 }
517 
518 static const struct fpga_manager_ops altera_cvp_ops = {
519 	.state		= altera_cvp_state,
520 	.write_init	= altera_cvp_write_init,
521 	.write		= altera_cvp_write,
522 	.write_complete	= altera_cvp_write_complete,
523 };
524 
525 static const struct cvp_priv cvp_priv_v1 = {
526 	.switch_clk	= altera_cvp_dummy_write,
527 	.block_size	= ALTERA_CVP_V1_SIZE,
528 	.poll_time_us	= V1_POLL_TIMEOUT_US,
529 	.user_time_us	= TIMEOUT_US,
530 };
531 
532 static const struct cvp_priv cvp_priv_v2 = {
533 	.clear_state	= altera_cvp_v2_clear_state,
534 	.wait_credit	= altera_cvp_v2_wait_for_credit,
535 	.block_size	= ALTERA_CVP_V2_SIZE,
536 	.poll_time_us	= V2_POLL_TIMEOUT_US,
537 	.user_time_us	= V2_USER_TIMEOUT_US,
538 };
539 
540 static ssize_t chkcfg_show(struct device_driver *dev, char *buf)
541 {
542 	return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg);
543 }
544 
545 static ssize_t chkcfg_store(struct device_driver *drv, const char *buf,
546 			    size_t count)
547 {
548 	int ret;
549 
550 	ret = kstrtobool(buf, &altera_cvp_chkcfg);
551 	if (ret)
552 		return ret;
553 
554 	return count;
555 }
556 
557 static DRIVER_ATTR_RW(chkcfg);
558 
559 static int altera_cvp_probe(struct pci_dev *pdev,
560 			    const struct pci_device_id *dev_id);
561 static void altera_cvp_remove(struct pci_dev *pdev);
562 
563 static struct pci_device_id altera_cvp_id_tbl[] = {
564 	{ PCI_VDEVICE(ALTERA, PCI_ANY_ID) },
565 	{ }
566 };
567 MODULE_DEVICE_TABLE(pci, altera_cvp_id_tbl);
568 
569 static struct pci_driver altera_cvp_driver = {
570 	.name   = DRV_NAME,
571 	.id_table = altera_cvp_id_tbl,
572 	.probe  = altera_cvp_probe,
573 	.remove = altera_cvp_remove,
574 };
575 
576 static int altera_cvp_probe(struct pci_dev *pdev,
577 			    const struct pci_device_id *dev_id)
578 {
579 	struct altera_cvp_conf *conf;
580 	struct fpga_manager *mgr;
581 	int ret, offset;
582 	u16 cmd, val;
583 	u32 regval;
584 
585 	/* Discover the Vendor Specific Offset for this device */
586 	offset = pci_find_next_ext_capability(pdev, 0, PCI_EXT_CAP_ID_VNDR);
587 	if (!offset) {
588 		dev_err(&pdev->dev, "No Vendor Specific Offset.\n");
589 		return -ENODEV;
590 	}
591 
592 	/*
593 	 * First check if this is the expected FPGA device. PCI config
594 	 * space access works without enabling the PCI device, memory
595 	 * space access is enabled further down.
596 	 */
597 	pci_read_config_word(pdev, offset + VSE_PCIE_EXT_CAP_ID, &val);
598 	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
599 		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
600 		return -ENODEV;
601 	}
602 
603 	pci_read_config_dword(pdev, offset + VSE_CVP_STATUS, &regval);
604 	if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
605 		dev_err(&pdev->dev,
606 			"CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
607 			regval);
608 		return -ENODEV;
609 	}
610 
611 	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
612 	if (!conf)
613 		return -ENOMEM;
614 
615 	conf->vsec_offset = offset;
616 
617 	/*
618 	 * Enable memory BAR access. We cannot use pci_enable_device() here
619 	 * because it will make the driver unusable with FPGA devices that
620 	 * have additional big IOMEM resources (e.g. 4GiB BARs) on 32-bit
621 	 * platform. Such BARs will not have an assigned address range and
622 	 * pci_enable_device() will fail, complaining about not claimed BAR,
623 	 * even if the concerned BAR is not needed for FPGA configuration
624 	 * at all. Thus, enable the device via PCI config space command.
625 	 */
626 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
627 	if (!(cmd & PCI_COMMAND_MEMORY)) {
628 		cmd |= PCI_COMMAND_MEMORY;
629 		pci_write_config_word(pdev, PCI_COMMAND, cmd);
630 	}
631 
632 	ret = pci_request_region(pdev, CVP_BAR, "CVP");
633 	if (ret) {
634 		dev_err(&pdev->dev, "Requesting CVP BAR region failed\n");
635 		goto err_disable;
636 	}
637 
638 	conf->pci_dev = pdev;
639 	conf->write_data = altera_cvp_write_data_iomem;
640 
641 	if (conf->vsec_offset == V1_VSEC_OFFSET)
642 		conf->priv = &cvp_priv_v1;
643 	else
644 		conf->priv = &cvp_priv_v2;
645 
646 	conf->map = pci_iomap(pdev, CVP_BAR, 0);
647 	if (!conf->map) {
648 		dev_warn(&pdev->dev, "Mapping CVP BAR failed\n");
649 		conf->write_data = altera_cvp_write_data_config;
650 	}
651 
652 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
653 		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
654 
655 	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
656 				   &altera_cvp_ops, conf);
657 	if (!mgr) {
658 		ret = -ENOMEM;
659 		goto err_unmap;
660 	}
661 
662 	pci_set_drvdata(pdev, mgr);
663 
664 	ret = fpga_mgr_register(mgr);
665 	if (ret)
666 		goto err_unmap;
667 
668 	return 0;
669 
670 err_unmap:
671 	if (conf->map)
672 		pci_iounmap(pdev, conf->map);
673 	pci_release_region(pdev, CVP_BAR);
674 err_disable:
675 	cmd &= ~PCI_COMMAND_MEMORY;
676 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
677 	return ret;
678 }
679 
680 static void altera_cvp_remove(struct pci_dev *pdev)
681 {
682 	struct fpga_manager *mgr = pci_get_drvdata(pdev);
683 	struct altera_cvp_conf *conf = mgr->priv;
684 	u16 cmd;
685 
686 	fpga_mgr_unregister(mgr);
687 	if (conf->map)
688 		pci_iounmap(pdev, conf->map);
689 	pci_release_region(pdev, CVP_BAR);
690 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
691 	cmd &= ~PCI_COMMAND_MEMORY;
692 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
693 }
694 
695 static int __init altera_cvp_init(void)
696 {
697 	int ret;
698 
699 	ret = pci_register_driver(&altera_cvp_driver);
700 	if (ret)
701 		return ret;
702 
703 	ret = driver_create_file(&altera_cvp_driver.driver,
704 				 &driver_attr_chkcfg);
705 	if (ret)
706 		pr_warn("Can't create sysfs chkcfg file\n");
707 
708 	return 0;
709 }
710 
711 static void __exit altera_cvp_exit(void)
712 {
713 	driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
714 	pci_unregister_driver(&altera_cvp_driver);
715 }
716 
717 module_init(altera_cvp_init);
718 module_exit(altera_cvp_exit);
719 
720 MODULE_LICENSE("GPL v2");
721 MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
722 MODULE_DESCRIPTION("Module to load Altera FPGA over CvP");
723