xref: /openbmc/linux/drivers/fpga/altera-cvp.c (revision d003d772)
1 /*
2  * FPGA Manager Driver for Altera Arria/Cyclone/Stratix CvP
3  *
4  * Copyright (C) 2017 DENX Software Engineering
5  *
6  * Anatolij Gustschin <agust@denx.de>
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  * Manage Altera FPGA firmware using PCIe CvP.
18  * Firmware must be in binary "rbf" format.
19  */
20 
21 #include <linux/delay.h>
22 #include <linux/device.h>
23 #include <linux/fpga/fpga-mgr.h>
24 #include <linux/module.h>
25 #include <linux/pci.h>
26 #include <linux/sizes.h>
27 
28 #define CVP_BAR		0	/* BAR used for data transfer in memory mode */
29 #define CVP_DUMMY_WR	244	/* dummy writes to clear CvP state machine */
30 #define TIMEOUT_US	2000	/* CVP STATUS timeout for USERMODE polling */
31 
32 /* Vendor Specific Extended Capability Registers */
33 #define VSE_PCIE_EXT_CAP_ID		0x200
34 #define VSE_PCIE_EXT_CAP_ID_VAL		0x000b	/* 16bit */
35 
36 #define VSE_CVP_STATUS			0x21c	/* 32bit */
37 #define VSE_CVP_STATUS_CFG_RDY		BIT(18)	/* CVP_CONFIG_READY */
38 #define VSE_CVP_STATUS_CFG_ERR		BIT(19)	/* CVP_CONFIG_ERROR */
39 #define VSE_CVP_STATUS_CVP_EN		BIT(20)	/* ctrl block is enabling CVP */
40 #define VSE_CVP_STATUS_USERMODE		BIT(21)	/* USERMODE */
41 #define VSE_CVP_STATUS_CFG_DONE		BIT(23)	/* CVP_CONFIG_DONE */
42 #define VSE_CVP_STATUS_PLD_CLK_IN_USE	BIT(24)	/* PLD_CLK_IN_USE */
43 
44 #define VSE_CVP_MODE_CTRL		0x220	/* 32bit */
45 #define VSE_CVP_MODE_CTRL_CVP_MODE	BIT(0)	/* CVP (1) or normal mode (0) */
46 #define VSE_CVP_MODE_CTRL_HIP_CLK_SEL	BIT(1) /* PMA (1) or fabric clock (0) */
47 #define VSE_CVP_MODE_CTRL_NUMCLKS_OFF	8	/* NUMCLKS bits offset */
48 #define VSE_CVP_MODE_CTRL_NUMCLKS_MASK	GENMASK(15, 8)
49 
50 #define VSE_CVP_DATA			0x228	/* 32bit */
51 #define VSE_CVP_PROG_CTRL		0x22c	/* 32bit */
52 #define VSE_CVP_PROG_CTRL_CONFIG	BIT(0)
53 #define VSE_CVP_PROG_CTRL_START_XFER	BIT(1)
54 
55 #define VSE_UNCOR_ERR_STATUS		0x234	/* 32bit */
56 #define VSE_UNCOR_ERR_CVP_CFG_ERR	BIT(5)	/* CVP_CONFIG_ERROR_LATCHED */
57 
58 #define DRV_NAME		"altera-cvp"
59 #define ALTERA_CVP_MGR_NAME	"Altera CvP FPGA Manager"
60 
61 /* Optional CvP config error status check for debugging */
62 static bool altera_cvp_chkcfg;
63 
64 struct altera_cvp_conf {
65 	struct fpga_manager	*mgr;
66 	struct pci_dev		*pci_dev;
67 	void __iomem		*map;
68 	void			(*write_data)(struct altera_cvp_conf *, u32);
69 	char			mgr_name[64];
70 	u8			numclks;
71 };
72 
73 static enum fpga_mgr_states altera_cvp_state(struct fpga_manager *mgr)
74 {
75 	struct altera_cvp_conf *conf = mgr->priv;
76 	u32 status;
77 
78 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &status);
79 
80 	if (status & VSE_CVP_STATUS_CFG_DONE)
81 		return FPGA_MGR_STATE_OPERATING;
82 
83 	if (status & VSE_CVP_STATUS_CVP_EN)
84 		return FPGA_MGR_STATE_POWER_UP;
85 
86 	return FPGA_MGR_STATE_UNKNOWN;
87 }
88 
89 static void altera_cvp_write_data_iomem(struct altera_cvp_conf *conf, u32 val)
90 {
91 	writel(val, conf->map);
92 }
93 
94 static void altera_cvp_write_data_config(struct altera_cvp_conf *conf, u32 val)
95 {
96 	pci_write_config_dword(conf->pci_dev, VSE_CVP_DATA, val);
97 }
98 
99 /* switches between CvP clock and internal clock */
100 static void altera_cvp_dummy_write(struct altera_cvp_conf *conf)
101 {
102 	unsigned int i;
103 	u32 val;
104 
105 	/* set 1 CVP clock cycle for every CVP Data Register Write */
106 	pci_read_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, &val);
107 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
108 	val |= 1 << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
109 	pci_write_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, val);
110 
111 	for (i = 0; i < CVP_DUMMY_WR; i++)
112 		conf->write_data(conf, 0); /* dummy data, could be any value */
113 }
114 
115 static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
116 				  u32 status_val, int timeout_us)
117 {
118 	unsigned int retries;
119 	u32 val;
120 
121 	retries = timeout_us / 10;
122 	if (timeout_us % 10)
123 		retries++;
124 
125 	do {
126 		pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
127 		if ((val & status_mask) == status_val)
128 			return 0;
129 
130 		/* use small usleep value to re-check and break early */
131 		usleep_range(10, 11);
132 	} while (--retries);
133 
134 	return -ETIMEDOUT;
135 }
136 
137 static int altera_cvp_teardown(struct fpga_manager *mgr,
138 			       struct fpga_image_info *info)
139 {
140 	struct altera_cvp_conf *conf = mgr->priv;
141 	struct pci_dev *pdev = conf->pci_dev;
142 	int ret;
143 	u32 val;
144 
145 	/* STEP 12 - reset START_XFER bit */
146 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
147 	val &= ~VSE_CVP_PROG_CTRL_START_XFER;
148 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
149 
150 	/* STEP 13 - reset CVP_CONFIG bit */
151 	val &= ~VSE_CVP_PROG_CTRL_CONFIG;
152 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
153 
154 	/*
155 	 * STEP 14
156 	 * - set CVP_NUMCLKS to 1 and then issue CVP_DUMMY_WR dummy
157 	 *   writes to the HIP
158 	 */
159 	altera_cvp_dummy_write(conf); /* from CVP clock to internal clock */
160 
161 	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
162 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0, 10);
163 	if (ret)
164 		dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");
165 
166 	return ret;
167 }
168 
169 static int altera_cvp_write_init(struct fpga_manager *mgr,
170 				 struct fpga_image_info *info,
171 				 const char *buf, size_t count)
172 {
173 	struct altera_cvp_conf *conf = mgr->priv;
174 	struct pci_dev *pdev = conf->pci_dev;
175 	u32 iflags, val;
176 	int ret;
177 
178 	iflags = info ? info->flags : 0;
179 
180 	if (iflags & FPGA_MGR_PARTIAL_RECONFIG) {
181 		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
182 		return -EINVAL;
183 	}
184 
185 	/* Determine allowed clock to data ratio */
186 	if (iflags & FPGA_MGR_COMPRESSED_BITSTREAM)
187 		conf->numclks = 8; /* ratio for all compressed images */
188 	else if (iflags & FPGA_MGR_ENCRYPTED_BITSTREAM)
189 		conf->numclks = 4; /* for uncompressed and encrypted images */
190 	else
191 		conf->numclks = 1; /* for uncompressed and unencrypted images */
192 
193 	/* STEP 1 - read CVP status and check CVP_EN flag */
194 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &val);
195 	if (!(val & VSE_CVP_STATUS_CVP_EN)) {
196 		dev_err(&mgr->dev, "CVP mode off: 0x%04x\n", val);
197 		return -ENODEV;
198 	}
199 
200 	if (val & VSE_CVP_STATUS_CFG_RDY) {
201 		dev_warn(&mgr->dev, "CvP already started, teardown first\n");
202 		ret = altera_cvp_teardown(mgr, info);
203 		if (ret)
204 			return ret;
205 	}
206 
207 	/*
208 	 * STEP 2
209 	 * - set HIP_CLK_SEL and CVP_MODE (must be set in the order mentioned)
210 	 */
211 	/* switch from fabric to PMA clock */
212 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
213 	val |= VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
214 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
215 
216 	/* set CVP mode */
217 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
218 	val |= VSE_CVP_MODE_CTRL_CVP_MODE;
219 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
220 
221 	/*
222 	 * STEP 3
223 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
224 	 */
225 	altera_cvp_dummy_write(conf);
226 
227 	/* STEP 4 - set CVP_CONFIG bit */
228 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
229 	/* request control block to begin transfer using CVP */
230 	val |= VSE_CVP_PROG_CTRL_CONFIG;
231 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
232 
233 	/* STEP 5 - poll CVP_CONFIG READY for 1 with 10us timeout */
234 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY,
235 				     VSE_CVP_STATUS_CFG_RDY, 10);
236 	if (ret) {
237 		dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
238 		return ret;
239 	}
240 
241 	/*
242 	 * STEP 6
243 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
244 	 */
245 	altera_cvp_dummy_write(conf);
246 
247 	/* STEP 7 - set START_XFER */
248 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
249 	val |= VSE_CVP_PROG_CTRL_START_XFER;
250 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
251 
252 	/* STEP 8 - start transfer (set CVP_NUMCLKS for bitstream) */
253 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
254 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
255 	val |= conf->numclks << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
256 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
257 
258 	return 0;
259 }
260 
261 static inline int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
262 {
263 	struct altera_cvp_conf *conf = mgr->priv;
264 	u32 val;
265 
266 	/* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
267 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
268 	if (val & VSE_CVP_STATUS_CFG_ERR) {
269 		dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
270 			bytes);
271 		return -EPROTO;
272 	}
273 	return 0;
274 }
275 
276 static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
277 			    size_t count)
278 {
279 	struct altera_cvp_conf *conf = mgr->priv;
280 	const u32 *data;
281 	size_t done, remaining;
282 	int status = 0;
283 	u32 mask;
284 
285 	/* STEP 9 - write 32-bit data from RBF file to CVP data register */
286 	data = (u32 *)buf;
287 	remaining = count;
288 	done = 0;
289 
290 	while (remaining >= 4) {
291 		conf->write_data(conf, *data++);
292 		done += 4;
293 		remaining -= 4;
294 
295 		/*
296 		 * STEP 10 (optional) and STEP 11
297 		 * - check error flag
298 		 * - loop until data transfer completed
299 		 * Config images can be huge (more than 40 MiB), so
300 		 * only check after a new 4k data block has been written.
301 		 * This reduces the number of checks and speeds up the
302 		 * configuration process.
303 		 */
304 		if (altera_cvp_chkcfg && !(done % SZ_4K)) {
305 			status = altera_cvp_chk_error(mgr, done);
306 			if (status < 0)
307 				return status;
308 		}
309 	}
310 
311 	/* write up to 3 trailing bytes, if any */
312 	mask = BIT(remaining * 8) - 1;
313 	if (mask)
314 		conf->write_data(conf, *data & mask);
315 
316 	if (altera_cvp_chkcfg)
317 		status = altera_cvp_chk_error(mgr, count);
318 
319 	return status;
320 }
321 
322 static int altera_cvp_write_complete(struct fpga_manager *mgr,
323 				     struct fpga_image_info *info)
324 {
325 	struct altera_cvp_conf *conf = mgr->priv;
326 	struct pci_dev *pdev = conf->pci_dev;
327 	int ret;
328 	u32 mask;
329 	u32 val;
330 
331 	ret = altera_cvp_teardown(mgr, info);
332 	if (ret)
333 		return ret;
334 
335 	/* STEP 16 - check CVP_CONFIG_ERROR_LATCHED bit */
336 	pci_read_config_dword(pdev, VSE_UNCOR_ERR_STATUS, &val);
337 	if (val & VSE_UNCOR_ERR_CVP_CFG_ERR) {
338 		dev_err(&mgr->dev, "detected CVP_CONFIG_ERROR_LATCHED!\n");
339 		return -EPROTO;
340 	}
341 
342 	/* STEP 17 - reset CVP_MODE and HIP_CLK_SEL bit */
343 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
344 	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
345 	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
346 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
347 
348 	/* STEP 18 - poll PLD_CLK_IN_USE and USER_MODE bits */
349 	mask = VSE_CVP_STATUS_PLD_CLK_IN_USE | VSE_CVP_STATUS_USERMODE;
350 	ret = altera_cvp_wait_status(conf, mask, mask, TIMEOUT_US);
351 	if (ret)
352 		dev_err(&mgr->dev, "PLD_CLK_IN_USE|USERMODE timeout\n");
353 
354 	return ret;
355 }
356 
357 static const struct fpga_manager_ops altera_cvp_ops = {
358 	.state		= altera_cvp_state,
359 	.write_init	= altera_cvp_write_init,
360 	.write		= altera_cvp_write,
361 	.write_complete	= altera_cvp_write_complete,
362 };
363 
364 static ssize_t chkcfg_show(struct device_driver *dev, char *buf)
365 {
366 	return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg);
367 }
368 
369 static ssize_t chkcfg_store(struct device_driver *drv, const char *buf,
370 			    size_t count)
371 {
372 	int ret;
373 
374 	ret = kstrtobool(buf, &altera_cvp_chkcfg);
375 	if (ret)
376 		return ret;
377 
378 	return count;
379 }
380 
381 static DRIVER_ATTR_RW(chkcfg);
382 
383 static int altera_cvp_probe(struct pci_dev *pdev,
384 			    const struct pci_device_id *dev_id);
385 static void altera_cvp_remove(struct pci_dev *pdev);
386 
387 static struct pci_device_id altera_cvp_id_tbl[] = {
388 	{ PCI_VDEVICE(ALTERA, PCI_ANY_ID) },
389 	{ }
390 };
391 MODULE_DEVICE_TABLE(pci, altera_cvp_id_tbl);
392 
393 static struct pci_driver altera_cvp_driver = {
394 	.name   = DRV_NAME,
395 	.id_table = altera_cvp_id_tbl,
396 	.probe  = altera_cvp_probe,
397 	.remove = altera_cvp_remove,
398 };
399 
400 static int altera_cvp_probe(struct pci_dev *pdev,
401 			    const struct pci_device_id *dev_id)
402 {
403 	struct altera_cvp_conf *conf;
404 	struct fpga_manager *mgr;
405 	u16 cmd, val;
406 	u32 regval;
407 	int ret;
408 
409 	/*
410 	 * First check if this is the expected FPGA device. PCI config
411 	 * space access works without enabling the PCI device, memory
412 	 * space access is enabled further down.
413 	 */
414 	pci_read_config_word(pdev, VSE_PCIE_EXT_CAP_ID, &val);
415 	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
416 		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
417 		return -ENODEV;
418 	}
419 
420 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &regval);
421 	if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
422 		dev_err(&pdev->dev,
423 			"CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
424 			regval);
425 		return -ENODEV;
426 	}
427 
428 	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
429 	if (!conf)
430 		return -ENOMEM;
431 
432 	/*
433 	 * Enable memory BAR access. We cannot use pci_enable_device() here
434 	 * because it will make the driver unusable with FPGA devices that
435 	 * have additional big IOMEM resources (e.g. 4GiB BARs) on 32-bit
436 	 * platform. Such BARs will not have an assigned address range and
437 	 * pci_enable_device() will fail, complaining about not claimed BAR,
438 	 * even if the concerned BAR is not needed for FPGA configuration
439 	 * at all. Thus, enable the device via PCI config space command.
440 	 */
441 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
442 	if (!(cmd & PCI_COMMAND_MEMORY)) {
443 		cmd |= PCI_COMMAND_MEMORY;
444 		pci_write_config_word(pdev, PCI_COMMAND, cmd);
445 	}
446 
447 	ret = pci_request_region(pdev, CVP_BAR, "CVP");
448 	if (ret) {
449 		dev_err(&pdev->dev, "Requesting CVP BAR region failed\n");
450 		goto err_disable;
451 	}
452 
453 	conf->pci_dev = pdev;
454 	conf->write_data = altera_cvp_write_data_iomem;
455 
456 	conf->map = pci_iomap(pdev, CVP_BAR, 0);
457 	if (!conf->map) {
458 		dev_warn(&pdev->dev, "Mapping CVP BAR failed\n");
459 		conf->write_data = altera_cvp_write_data_config;
460 	}
461 
462 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
463 		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
464 
465 	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
466 				   &altera_cvp_ops, conf);
467 	if (!mgr) {
468 		ret = -ENOMEM;
469 		goto err_unmap;
470 	}
471 
472 	pci_set_drvdata(pdev, mgr);
473 
474 	ret = fpga_mgr_register(mgr);
475 	if (ret)
476 		goto err_unmap;
477 
478 	return 0;
479 
480 err_unmap:
481 	if (conf->map)
482 		pci_iounmap(pdev, conf->map);
483 	pci_release_region(pdev, CVP_BAR);
484 err_disable:
485 	cmd &= ~PCI_COMMAND_MEMORY;
486 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
487 	return ret;
488 }
489 
490 static void altera_cvp_remove(struct pci_dev *pdev)
491 {
492 	struct fpga_manager *mgr = pci_get_drvdata(pdev);
493 	struct altera_cvp_conf *conf = mgr->priv;
494 	u16 cmd;
495 
496 	fpga_mgr_unregister(mgr);
497 	if (conf->map)
498 		pci_iounmap(pdev, conf->map);
499 	pci_release_region(pdev, CVP_BAR);
500 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
501 	cmd &= ~PCI_COMMAND_MEMORY;
502 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
503 }
504 
505 static int __init altera_cvp_init(void)
506 {
507 	int ret;
508 
509 	ret = pci_register_driver(&altera_cvp_driver);
510 	if (ret)
511 		return ret;
512 
513 	ret = driver_create_file(&altera_cvp_driver.driver,
514 				 &driver_attr_chkcfg);
515 	if (ret)
516 		pr_warn("Can't create sysfs chkcfg file\n");
517 
518 	return 0;
519 }
520 
521 static void __exit altera_cvp_exit(void)
522 {
523 	driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
524 	pci_unregister_driver(&altera_cvp_driver);
525 }
526 
527 module_init(altera_cvp_init);
528 module_exit(altera_cvp_exit);
529 
530 MODULE_LICENSE("GPL v2");
531 MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
532 MODULE_DESCRIPTION("Module to load Altera FPGA over CvP");
533