xref: /openbmc/linux/drivers/fpga/altera-cvp.c (revision ccd51b9f)
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 *, u32);
61 	char			mgr_name[64];
62 	u8			numclks;
63 };
64 
65 static enum fpga_mgr_states altera_cvp_state(struct fpga_manager *mgr)
66 {
67 	struct altera_cvp_conf *conf = mgr->priv;
68 	u32 status;
69 
70 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &status);
71 
72 	if (status & VSE_CVP_STATUS_CFG_DONE)
73 		return FPGA_MGR_STATE_OPERATING;
74 
75 	if (status & VSE_CVP_STATUS_CVP_EN)
76 		return FPGA_MGR_STATE_POWER_UP;
77 
78 	return FPGA_MGR_STATE_UNKNOWN;
79 }
80 
81 static void altera_cvp_write_data_iomem(struct altera_cvp_conf *conf, u32 val)
82 {
83 	writel(val, conf->map);
84 }
85 
86 static void altera_cvp_write_data_config(struct altera_cvp_conf *conf, u32 val)
87 {
88 	pci_write_config_dword(conf->pci_dev, VSE_CVP_DATA, val);
89 }
90 
91 /* switches between CvP clock and internal clock */
92 static void altera_cvp_dummy_write(struct altera_cvp_conf *conf)
93 {
94 	unsigned int i;
95 	u32 val;
96 
97 	/* set 1 CVP clock cycle for every CVP Data Register Write */
98 	pci_read_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, &val);
99 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
100 	val |= 1 << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
101 	pci_write_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, val);
102 
103 	for (i = 0; i < CVP_DUMMY_WR; i++)
104 		conf->write_data(conf, 0); /* dummy data, could be any value */
105 }
106 
107 static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
108 				  u32 status_val, int timeout_us)
109 {
110 	unsigned int retries;
111 	u32 val;
112 
113 	retries = timeout_us / 10;
114 	if (timeout_us % 10)
115 		retries++;
116 
117 	do {
118 		pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
119 		if ((val & status_mask) == status_val)
120 			return 0;
121 
122 		/* use small usleep value to re-check and break early */
123 		usleep_range(10, 11);
124 	} while (--retries);
125 
126 	return -ETIMEDOUT;
127 }
128 
129 static int altera_cvp_teardown(struct fpga_manager *mgr,
130 			       struct fpga_image_info *info)
131 {
132 	struct altera_cvp_conf *conf = mgr->priv;
133 	struct pci_dev *pdev = conf->pci_dev;
134 	int ret;
135 	u32 val;
136 
137 	/* STEP 12 - reset START_XFER bit */
138 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
139 	val &= ~VSE_CVP_PROG_CTRL_START_XFER;
140 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
141 
142 	/* STEP 13 - reset CVP_CONFIG bit */
143 	val &= ~VSE_CVP_PROG_CTRL_CONFIG;
144 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
145 
146 	/*
147 	 * STEP 14
148 	 * - set CVP_NUMCLKS to 1 and then issue CVP_DUMMY_WR dummy
149 	 *   writes to the HIP
150 	 */
151 	altera_cvp_dummy_write(conf); /* from CVP clock to internal clock */
152 
153 	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
154 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0, 10);
155 	if (ret)
156 		dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");
157 
158 	return ret;
159 }
160 
161 static int altera_cvp_write_init(struct fpga_manager *mgr,
162 				 struct fpga_image_info *info,
163 				 const char *buf, size_t count)
164 {
165 	struct altera_cvp_conf *conf = mgr->priv;
166 	struct pci_dev *pdev = conf->pci_dev;
167 	u32 iflags, val;
168 	int ret;
169 
170 	iflags = info ? info->flags : 0;
171 
172 	if (iflags & FPGA_MGR_PARTIAL_RECONFIG) {
173 		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
174 		return -EINVAL;
175 	}
176 
177 	/* Determine allowed clock to data ratio */
178 	if (iflags & FPGA_MGR_COMPRESSED_BITSTREAM)
179 		conf->numclks = 8; /* ratio for all compressed images */
180 	else if (iflags & FPGA_MGR_ENCRYPTED_BITSTREAM)
181 		conf->numclks = 4; /* for uncompressed and encrypted images */
182 	else
183 		conf->numclks = 1; /* for uncompressed and unencrypted images */
184 
185 	/* STEP 1 - read CVP status and check CVP_EN flag */
186 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &val);
187 	if (!(val & VSE_CVP_STATUS_CVP_EN)) {
188 		dev_err(&mgr->dev, "CVP mode off: 0x%04x\n", val);
189 		return -ENODEV;
190 	}
191 
192 	if (val & VSE_CVP_STATUS_CFG_RDY) {
193 		dev_warn(&mgr->dev, "CvP already started, teardown first\n");
194 		ret = altera_cvp_teardown(mgr, info);
195 		if (ret)
196 			return ret;
197 	}
198 
199 	/*
200 	 * STEP 2
201 	 * - set HIP_CLK_SEL and CVP_MODE (must be set in the order mentioned)
202 	 */
203 	/* switch from fabric to PMA clock */
204 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
205 	val |= VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
206 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
207 
208 	/* set CVP mode */
209 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
210 	val |= VSE_CVP_MODE_CTRL_CVP_MODE;
211 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
212 
213 	/*
214 	 * STEP 3
215 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
216 	 */
217 	altera_cvp_dummy_write(conf);
218 
219 	/* STEP 4 - set CVP_CONFIG bit */
220 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
221 	/* request control block to begin transfer using CVP */
222 	val |= VSE_CVP_PROG_CTRL_CONFIG;
223 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
224 
225 	/* STEP 5 - poll CVP_CONFIG READY for 1 with 10us timeout */
226 	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY,
227 				     VSE_CVP_STATUS_CFG_RDY, 10);
228 	if (ret) {
229 		dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
230 		return ret;
231 	}
232 
233 	/*
234 	 * STEP 6
235 	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
236 	 */
237 	altera_cvp_dummy_write(conf);
238 
239 	/* STEP 7 - set START_XFER */
240 	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
241 	val |= VSE_CVP_PROG_CTRL_START_XFER;
242 	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
243 
244 	/* STEP 8 - start transfer (set CVP_NUMCLKS for bitstream) */
245 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
246 	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
247 	val |= conf->numclks << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
248 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
249 
250 	return 0;
251 }
252 
253 static inline int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
254 {
255 	struct altera_cvp_conf *conf = mgr->priv;
256 	u32 val;
257 
258 	/* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
259 	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
260 	if (val & VSE_CVP_STATUS_CFG_ERR) {
261 		dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
262 			bytes);
263 		return -EPROTO;
264 	}
265 	return 0;
266 }
267 
268 static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
269 			    size_t count)
270 {
271 	struct altera_cvp_conf *conf = mgr->priv;
272 	const u32 *data;
273 	size_t done, remaining;
274 	int status = 0;
275 	u32 mask;
276 
277 	/* STEP 9 - write 32-bit data from RBF file to CVP data register */
278 	data = (u32 *)buf;
279 	remaining = count;
280 	done = 0;
281 
282 	while (remaining >= 4) {
283 		conf->write_data(conf, *data++);
284 		done += 4;
285 		remaining -= 4;
286 
287 		/*
288 		 * STEP 10 (optional) and STEP 11
289 		 * - check error flag
290 		 * - loop until data transfer completed
291 		 * Config images can be huge (more than 40 MiB), so
292 		 * only check after a new 4k data block has been written.
293 		 * This reduces the number of checks and speeds up the
294 		 * configuration process.
295 		 */
296 		if (altera_cvp_chkcfg && !(done % SZ_4K)) {
297 			status = altera_cvp_chk_error(mgr, done);
298 			if (status < 0)
299 				return status;
300 		}
301 	}
302 
303 	/* write up to 3 trailing bytes, if any */
304 	mask = BIT(remaining * 8) - 1;
305 	if (mask)
306 		conf->write_data(conf, *data & mask);
307 
308 	if (altera_cvp_chkcfg)
309 		status = altera_cvp_chk_error(mgr, count);
310 
311 	return status;
312 }
313 
314 static int altera_cvp_write_complete(struct fpga_manager *mgr,
315 				     struct fpga_image_info *info)
316 {
317 	struct altera_cvp_conf *conf = mgr->priv;
318 	struct pci_dev *pdev = conf->pci_dev;
319 	int ret;
320 	u32 mask;
321 	u32 val;
322 
323 	ret = altera_cvp_teardown(mgr, info);
324 	if (ret)
325 		return ret;
326 
327 	/* STEP 16 - check CVP_CONFIG_ERROR_LATCHED bit */
328 	pci_read_config_dword(pdev, VSE_UNCOR_ERR_STATUS, &val);
329 	if (val & VSE_UNCOR_ERR_CVP_CFG_ERR) {
330 		dev_err(&mgr->dev, "detected CVP_CONFIG_ERROR_LATCHED!\n");
331 		return -EPROTO;
332 	}
333 
334 	/* STEP 17 - reset CVP_MODE and HIP_CLK_SEL bit */
335 	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
336 	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
337 	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
338 	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
339 
340 	/* STEP 18 - poll PLD_CLK_IN_USE and USER_MODE bits */
341 	mask = VSE_CVP_STATUS_PLD_CLK_IN_USE | VSE_CVP_STATUS_USERMODE;
342 	ret = altera_cvp_wait_status(conf, mask, mask, TIMEOUT_US);
343 	if (ret)
344 		dev_err(&mgr->dev, "PLD_CLK_IN_USE|USERMODE timeout\n");
345 
346 	return ret;
347 }
348 
349 static const struct fpga_manager_ops altera_cvp_ops = {
350 	.state		= altera_cvp_state,
351 	.write_init	= altera_cvp_write_init,
352 	.write		= altera_cvp_write,
353 	.write_complete	= altera_cvp_write_complete,
354 };
355 
356 static ssize_t chkcfg_show(struct device_driver *dev, char *buf)
357 {
358 	return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg);
359 }
360 
361 static ssize_t chkcfg_store(struct device_driver *drv, const char *buf,
362 			    size_t count)
363 {
364 	int ret;
365 
366 	ret = kstrtobool(buf, &altera_cvp_chkcfg);
367 	if (ret)
368 		return ret;
369 
370 	return count;
371 }
372 
373 static DRIVER_ATTR_RW(chkcfg);
374 
375 static int altera_cvp_probe(struct pci_dev *pdev,
376 			    const struct pci_device_id *dev_id);
377 static void altera_cvp_remove(struct pci_dev *pdev);
378 
379 static struct pci_device_id altera_cvp_id_tbl[] = {
380 	{ PCI_VDEVICE(ALTERA, PCI_ANY_ID) },
381 	{ }
382 };
383 MODULE_DEVICE_TABLE(pci, altera_cvp_id_tbl);
384 
385 static struct pci_driver altera_cvp_driver = {
386 	.name   = DRV_NAME,
387 	.id_table = altera_cvp_id_tbl,
388 	.probe  = altera_cvp_probe,
389 	.remove = altera_cvp_remove,
390 };
391 
392 static int altera_cvp_probe(struct pci_dev *pdev,
393 			    const struct pci_device_id *dev_id)
394 {
395 	struct altera_cvp_conf *conf;
396 	struct fpga_manager *mgr;
397 	u16 cmd, val;
398 	u32 regval;
399 	int ret;
400 
401 	/*
402 	 * First check if this is the expected FPGA device. PCI config
403 	 * space access works without enabling the PCI device, memory
404 	 * space access is enabled further down.
405 	 */
406 	pci_read_config_word(pdev, VSE_PCIE_EXT_CAP_ID, &val);
407 	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
408 		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
409 		return -ENODEV;
410 	}
411 
412 	pci_read_config_dword(pdev, VSE_CVP_STATUS, &regval);
413 	if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
414 		dev_err(&pdev->dev,
415 			"CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
416 			regval);
417 		return -ENODEV;
418 	}
419 
420 	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
421 	if (!conf)
422 		return -ENOMEM;
423 
424 	/*
425 	 * Enable memory BAR access. We cannot use pci_enable_device() here
426 	 * because it will make the driver unusable with FPGA devices that
427 	 * have additional big IOMEM resources (e.g. 4GiB BARs) on 32-bit
428 	 * platform. Such BARs will not have an assigned address range and
429 	 * pci_enable_device() will fail, complaining about not claimed BAR,
430 	 * even if the concerned BAR is not needed for FPGA configuration
431 	 * at all. Thus, enable the device via PCI config space command.
432 	 */
433 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
434 	if (!(cmd & PCI_COMMAND_MEMORY)) {
435 		cmd |= PCI_COMMAND_MEMORY;
436 		pci_write_config_word(pdev, PCI_COMMAND, cmd);
437 	}
438 
439 	ret = pci_request_region(pdev, CVP_BAR, "CVP");
440 	if (ret) {
441 		dev_err(&pdev->dev, "Requesting CVP BAR region failed\n");
442 		goto err_disable;
443 	}
444 
445 	conf->pci_dev = pdev;
446 	conf->write_data = altera_cvp_write_data_iomem;
447 
448 	conf->map = pci_iomap(pdev, CVP_BAR, 0);
449 	if (!conf->map) {
450 		dev_warn(&pdev->dev, "Mapping CVP BAR failed\n");
451 		conf->write_data = altera_cvp_write_data_config;
452 	}
453 
454 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
455 		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
456 
457 	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
458 				   &altera_cvp_ops, conf);
459 	if (!mgr) {
460 		ret = -ENOMEM;
461 		goto err_unmap;
462 	}
463 
464 	pci_set_drvdata(pdev, mgr);
465 
466 	ret = fpga_mgr_register(mgr);
467 	if (ret)
468 		goto err_unmap;
469 
470 	return 0;
471 
472 err_unmap:
473 	if (conf->map)
474 		pci_iounmap(pdev, conf->map);
475 	pci_release_region(pdev, CVP_BAR);
476 err_disable:
477 	cmd &= ~PCI_COMMAND_MEMORY;
478 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
479 	return ret;
480 }
481 
482 static void altera_cvp_remove(struct pci_dev *pdev)
483 {
484 	struct fpga_manager *mgr = pci_get_drvdata(pdev);
485 	struct altera_cvp_conf *conf = mgr->priv;
486 	u16 cmd;
487 
488 	fpga_mgr_unregister(mgr);
489 	if (conf->map)
490 		pci_iounmap(pdev, conf->map);
491 	pci_release_region(pdev, CVP_BAR);
492 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
493 	cmd &= ~PCI_COMMAND_MEMORY;
494 	pci_write_config_word(pdev, PCI_COMMAND, cmd);
495 }
496 
497 static int __init altera_cvp_init(void)
498 {
499 	int ret;
500 
501 	ret = pci_register_driver(&altera_cvp_driver);
502 	if (ret)
503 		return ret;
504 
505 	ret = driver_create_file(&altera_cvp_driver.driver,
506 				 &driver_attr_chkcfg);
507 	if (ret)
508 		pr_warn("Can't create sysfs chkcfg file\n");
509 
510 	return 0;
511 }
512 
513 static void __exit altera_cvp_exit(void)
514 {
515 	driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
516 	pci_unregister_driver(&altera_cvp_driver);
517 }
518 
519 module_init(altera_cvp_init);
520 module_exit(altera_cvp_exit);
521 
522 MODULE_LICENSE("GPL v2");
523 MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
524 MODULE_DESCRIPTION("Module to load Altera FPGA over CvP");
525