xref: /openbmc/linux/drivers/fpga/altera-cvp.c (revision e6f4c346)
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		0x200
26 #define VSE_PCIE_EXT_CAP_ID_VAL		0x000b	/* 16bit */
27 
28 #define VSE_CVP_STATUS			0x21c	/* 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		0x220	/* 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			0x228	/* 32bit */
43 #define VSE_CVP_PROG_CTRL		0x22c	/* 32bit */
44 #define VSE_CVP_PROG_CTRL_CONFIG	BIT(0)
45 #define VSE_CVP_PROG_CTRL_START_XFER	BIT(1)
46 
47 #define VSE_UNCOR_ERR_STATUS		0x234	/* 32bit */
48 #define VSE_UNCOR_ERR_CVP_CFG_ERR	BIT(5)	/* CVP_CONFIG_ERROR_LATCHED */
49 
50 #define DRV_NAME		"altera-cvp"
51 #define ALTERA_CVP_MGR_NAME	"Altera CvP FPGA Manager"
52 
53 /* Optional CvP config error status check for debugging */
54 static bool altera_cvp_chkcfg;
55 
56 struct altera_cvp_conf {
57 	struct fpga_manager	*mgr;
58 	struct pci_dev		*pci_dev;
59 	void __iomem		*map;
60 	void			(*write_data)(struct altera_cvp_conf *conf,
61 					      u32 data);
62 	char			mgr_name[64];
63 	u8			numclks;
64 };
65 
66 static enum fpga_mgr_states altera_cvp_state(struct fpga_manager *mgr)
67 {
68 	struct altera_cvp_conf *conf = mgr->priv;
69 	u32 status;
70 
71 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &status);
72 
73 	if (status & VSE_CVP_STATUS_CFG_DONE)
74 		return FPGA_MGR_STATE_OPERATING;
75 
76 	if (status & VSE_CVP_STATUS_CVP_EN)
77 		return FPGA_MGR_STATE_POWER_UP;
78 
79 	return FPGA_MGR_STATE_UNKNOWN;
80 }
81 
82 static void altera_cvp_write_data_iomem(struct altera_cvp_conf *conf, u32 val)
83 {
84 	writel(val, conf->map);
85 }
86 
87 static void altera_cvp_write_data_config(struct altera_cvp_conf *conf, u32 val)
88 {
89 	pci_write_config_dword(conf->pci_dev, VSE_CVP_DATA, val);
90 }
91 
92 /* switches between CvP clock and internal clock */
93 static void altera_cvp_dummy_write(struct altera_cvp_conf *conf)
94 {
95 	unsigned int i;
96 	u32 val;
97 
98 	/* set 1 CVP clock cycle for every CVP Data Register Write */
99 	pci_read_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, &val);
100 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
101 	val |= 1 << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
102 	pci_write_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, val);
103 
104 	for (i = 0; i < CVP_DUMMY_WR; i++)
105 		conf->write_data(conf, 0); /* dummy data, could be any value */
106 }
107 
108 static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
109 				  u32 status_val, int timeout_us)
110 {
111 	unsigned int retries;
112 	u32 val;
113 
114 	retries = timeout_us / 10;
115 	if (timeout_us % 10)
116 		retries++;
117 
118 	do {
119 		pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
120 		if ((val & status_mask) == status_val)
121 			return 0;
122 
123 		/* use small usleep value to re-check and break early */
124 		usleep_range(10, 11);
125 	} while (--retries);
126 
127 	return -ETIMEDOUT;
128 }
129 
130 static int altera_cvp_teardown(struct fpga_manager *mgr,
131 			       struct fpga_image_info *info)
132 {
133 	struct altera_cvp_conf *conf = mgr->priv;
134 	struct pci_dev *pdev = conf->pci_dev;
135 	int ret;
136 	u32 val;
137 
138 	/* STEP 12 - reset START_XFER bit */
139 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
140 	val &= ~VSE_CVP_PROG_CTRL_START_XFER;
141 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
142 
143 	/* STEP 13 - reset CVP_CONFIG bit */
144 	val &= ~VSE_CVP_PROG_CTRL_CONFIG;
145 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
146 
147 	/*
148 	 * STEP 14
149 	 * - set CVP_NUMCLKS to 1 and then issue CVP_DUMMY_WR dummy
150 	 *   writes to the HIP
151 	 */
152 	altera_cvp_dummy_write(conf); /* from CVP clock to internal clock */
153 
154 	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
155 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0, 10);
156 	if (ret)
157 		dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");
158 
159 	return ret;
160 }
161 
162 static int altera_cvp_write_init(struct fpga_manager *mgr,
163 				 struct fpga_image_info *info,
164 				 const char *buf, size_t count)
165 {
166 	struct altera_cvp_conf *conf = mgr->priv;
167 	struct pci_dev *pdev = conf->pci_dev;
168 	u32 iflags, val;
169 	int ret;
170 
171 	iflags = info ? info->flags : 0;
172 
173 	if (iflags & FPGA_MGR_PARTIAL_RECONFIG) {
174 		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
175 		return -EINVAL;
176 	}
177 
178 	/* Determine allowed clock to data ratio */
179 	if (iflags & FPGA_MGR_COMPRESSED_BITSTREAM)
180 		conf->numclks = 8; /* ratio for all compressed images */
181 	else if (iflags & FPGA_MGR_ENCRYPTED_BITSTREAM)
182 		conf->numclks = 4; /* for uncompressed and encrypted images */
183 	else
184 		conf->numclks = 1; /* for uncompressed and unencrypted images */
185 
186 	/* STEP 1 - read CVP status and check CVP_EN flag */
187 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &val);
188 	if (!(val & VSE_CVP_STATUS_CVP_EN)) {
189 		dev_err(&mgr->dev, "CVP mode off: 0x%04x\n", val);
190 		return -ENODEV;
191 	}
192 
193 	if (val & VSE_CVP_STATUS_CFG_RDY) {
194 		dev_warn(&mgr->dev, "CvP already started, teardown first\n");
195 		ret = altera_cvp_teardown(mgr, info);
196 		if (ret)
197 			return ret;
198 	}
199 
200 	/*
201 	 * STEP 2
202 	 * - set HIP_CLK_SEL and CVP_MODE (must be set in the order mentioned)
203 	 */
204 	/* switch from fabric to PMA clock */
205 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
206 	val |= VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
207 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
208 
209 	/* set CVP mode */
210 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
211 	val |= VSE_CVP_MODE_CTRL_CVP_MODE;
212 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
213 
214 	/*
215 	 * STEP 3
216 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
217 	 */
218 	altera_cvp_dummy_write(conf);
219 
220 	/* STEP 4 - set CVP_CONFIG bit */
221 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
222 	/* request control block to begin transfer using CVP */
223 	val |= VSE_CVP_PROG_CTRL_CONFIG;
224 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
225 
226 	/* STEP 5 - poll CVP_CONFIG READY for 1 with 10us timeout */
227 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY,
228 				     VSE_CVP_STATUS_CFG_RDY, 10);
229 	if (ret) {
230 		dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
231 		return ret;
232 	}
233 
234 	/*
235 	 * STEP 6
236 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
237 	 */
238 	altera_cvp_dummy_write(conf);
239 
240 	/* STEP 7 - set START_XFER */
241 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
242 	val |= VSE_CVP_PROG_CTRL_START_XFER;
243 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
244 
245 	/* STEP 8 - start transfer (set CVP_NUMCLKS for bitstream) */
246 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
247 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
248 	val |= conf->numclks << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
249 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
250 
251 	return 0;
252 }
253 
254 static inline int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
255 {
256 	struct altera_cvp_conf *conf = mgr->priv;
257 	u32 val;
258 
259 	/* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
260 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
261 	if (val & VSE_CVP_STATUS_CFG_ERR) {
262 		dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
263 			bytes);
264 		return -EPROTO;
265 	}
266 	return 0;
267 }
268 
269 static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
270 			    size_t count)
271 {
272 	struct altera_cvp_conf *conf = mgr->priv;
273 	const u32 *data;
274 	size_t done, remaining;
275 	int status = 0;
276 	u32 mask;
277 
278 	/* STEP 9 - write 32-bit data from RBF file to CVP data register */
279 	data = (u32 *)buf;
280 	remaining = count;
281 	done = 0;
282 
283 	while (remaining >= 4) {
284 		conf->write_data(conf, *data++);
285 		done += 4;
286 		remaining -= 4;
287 
288 		/*
289 		 * STEP 10 (optional) and STEP 11
290 		 * - check error flag
291 		 * - loop until data transfer completed
292 		 * Config images can be huge (more than 40 MiB), so
293 		 * only check after a new 4k data block has been written.
294 		 * This reduces the number of checks and speeds up the
295 		 * configuration process.
296 		 */
297 		if (altera_cvp_chkcfg && !(done % SZ_4K)) {
298 			status = altera_cvp_chk_error(mgr, done);
299 			if (status < 0)
300 				return status;
301 		}
302 	}
303 
304 	/* write up to 3 trailing bytes, if any */
305 	mask = BIT(remaining * 8) - 1;
306 	if (mask)
307 		conf->write_data(conf, *data & mask);
308 
309 	if (altera_cvp_chkcfg)
310 		status = altera_cvp_chk_error(mgr, count);
311 
312 	return status;
313 }
314 
315 static int altera_cvp_write_complete(struct fpga_manager *mgr,
316 				     struct fpga_image_info *info)
317 {
318 	struct altera_cvp_conf *conf = mgr->priv;
319 	struct pci_dev *pdev = conf->pci_dev;
320 	int ret;
321 	u32 mask;
322 	u32 val;
323 
324 	ret = altera_cvp_teardown(mgr, info);
325 	if (ret)
326 		return ret;
327 
328 	/* STEP 16 - check CVP_CONFIG_ERROR_LATCHED bit */
329 	pci_read_config_dword(pdev, VSE_UNCOR_ERR_STATUS, &val);
330 	if (val & VSE_UNCOR_ERR_CVP_CFG_ERR) {
331 		dev_err(&mgr->dev, "detected CVP_CONFIG_ERROR_LATCHED!\n");
332 		return -EPROTO;
333 	}
334 
335 	/* STEP 17 - reset CVP_MODE and HIP_CLK_SEL bit */
336 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
337 	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
338 	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
339 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
340 
341 	/* STEP 18 - poll PLD_CLK_IN_USE and USER_MODE bits */
342 	mask = VSE_CVP_STATUS_PLD_CLK_IN_USE | VSE_CVP_STATUS_USERMODE;
343 	ret = altera_cvp_wait_status(conf, mask, mask, TIMEOUT_US);
344 	if (ret)
345 		dev_err(&mgr->dev, "PLD_CLK_IN_USE|USERMODE timeout\n");
346 
347 	return ret;
348 }
349 
350 static const struct fpga_manager_ops altera_cvp_ops = {
351 	.state		= altera_cvp_state,
352 	.write_init	= altera_cvp_write_init,
353 	.write		= altera_cvp_write,
354 	.write_complete	= altera_cvp_write_complete,
355 };
356 
357 static ssize_t chkcfg_show(struct device_driver *dev, char *buf)
358 {
359 	return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg);
360 }
361 
362 static ssize_t chkcfg_store(struct device_driver *drv, const char *buf,
363 			    size_t count)
364 {
365 	int ret;
366 
367 	ret = kstrtobool(buf, &altera_cvp_chkcfg);
368 	if (ret)
369 		return ret;
370 
371 	return count;
372 }
373 
374 static DRIVER_ATTR_RW(chkcfg);
375 
376 static int altera_cvp_probe(struct pci_dev *pdev,
377 			    const struct pci_device_id *dev_id);
378 static void altera_cvp_remove(struct pci_dev *pdev);
379 
380 static struct pci_device_id altera_cvp_id_tbl[] = {
381 	{ PCI_VDEVICE(ALTERA, PCI_ANY_ID) },
382 	{ }
383 };
384 MODULE_DEVICE_TABLE(pci, altera_cvp_id_tbl);
385 
386 static struct pci_driver altera_cvp_driver = {
387 	.name   = DRV_NAME,
388 	.id_table = altera_cvp_id_tbl,
389 	.probe  = altera_cvp_probe,
390 	.remove = altera_cvp_remove,
391 };
392 
393 static int altera_cvp_probe(struct pci_dev *pdev,
394 			    const struct pci_device_id *dev_id)
395 {
396 	struct altera_cvp_conf *conf;
397 	struct fpga_manager *mgr;
398 	u16 cmd, val;
399 	u32 regval;
400 	int ret;
401 
402 	/*
403 	 * First check if this is the expected FPGA device. PCI config
404 	 * space access works without enabling the PCI device, memory
405 	 * space access is enabled further down.
406 	 */
407 	pci_read_config_word(pdev, VSE_PCIE_EXT_CAP_ID, &val);
408 	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
409 		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
410 		return -ENODEV;
411 	}
412 
413 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &regval);
414 	if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
415 		dev_err(&pdev->dev,
416 			"CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
417 			regval);
418 		return -ENODEV;
419 	}
420 
421 	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
422 	if (!conf)
423 		return -ENOMEM;
424 
425 	/*
426 	 * Enable memory BAR access. We cannot use pci_enable_device() here
427 	 * because it will make the driver unusable with FPGA devices that
428 	 * have additional big IOMEM resources (e.g. 4GiB BARs) on 32-bit
429 	 * platform. Such BARs will not have an assigned address range and
430 	 * pci_enable_device() will fail, complaining about not claimed BAR,
431 	 * even if the concerned BAR is not needed for FPGA configuration
432 	 * at all. Thus, enable the device via PCI config space command.
433 	 */
434 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
435 	if (!(cmd & PCI_COMMAND_MEMORY)) {
436 		cmd |= PCI_COMMAND_MEMORY;
437 		pci_write_config_word(pdev, PCI_COMMAND, cmd);
438 	}
439 
440 	ret = pci_request_region(pdev, CVP_BAR, "CVP");
441 	if (ret) {
442 		dev_err(&pdev->dev, "Requesting CVP BAR region failed\n");
443 		goto err_disable;
444 	}
445 
446 	conf->pci_dev = pdev;
447 	conf->write_data = altera_cvp_write_data_iomem;
448 
449 	conf->map = pci_iomap(pdev, CVP_BAR, 0);
450 	if (!conf->map) {
451 		dev_warn(&pdev->dev, "Mapping CVP BAR failed\n");
452 		conf->write_data = altera_cvp_write_data_config;
453 	}
454 
455 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
456 		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
457 
458 	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
459 				   &altera_cvp_ops, conf);
460 	if (!mgr) {
461 		ret = -ENOMEM;
462 		goto err_unmap;
463 	}
464 
465 	pci_set_drvdata(pdev, mgr);
466 
467 	ret = fpga_mgr_register(mgr);
468 	if (ret)
469 		goto err_unmap;
470 
471 	return 0;
472 
473 err_unmap:
474 	if (conf->map)
475 		pci_iounmap(pdev, conf->map);
476 	pci_release_region(pdev, CVP_BAR);
477 err_disable:
478 	cmd &= ~PCI_COMMAND_MEMORY;
479 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
480 	return ret;
481 }
482 
483 static void altera_cvp_remove(struct pci_dev *pdev)
484 {
485 	struct fpga_manager *mgr = pci_get_drvdata(pdev);
486 	struct altera_cvp_conf *conf = mgr->priv;
487 	u16 cmd;
488 
489 	fpga_mgr_unregister(mgr);
490 	if (conf->map)
491 		pci_iounmap(pdev, conf->map);
492 	pci_release_region(pdev, CVP_BAR);
493 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
494 	cmd &= ~PCI_COMMAND_MEMORY;
495 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
496 }
497 
498 static int __init altera_cvp_init(void)
499 {
500 	int ret;
501 
502 	ret = pci_register_driver(&altera_cvp_driver);
503 	if (ret)
504 		return ret;
505 
506 	ret = driver_create_file(&altera_cvp_driver.driver,
507 				 &driver_attr_chkcfg);
508 	if (ret)
509 		pr_warn("Can't create sysfs chkcfg file\n");
510 
511 	return 0;
512 }
513 
514 static void __exit altera_cvp_exit(void)
515 {
516 	driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
517 	pci_unregister_driver(&altera_cvp_driver);
518 }
519 
520 module_init(altera_cvp_init);
521 module_exit(altera_cvp_exit);
522 
523 MODULE_LICENSE("GPL v2");
524 MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
525 MODULE_DESCRIPTION("Module to load Altera FPGA over CvP");
526