xref: /openbmc/linux/drivers/memory/brcmstb_dpfe.c (revision 3cf3cdea)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * DDR PHY Front End (DPFE) driver for Broadcom set top box SoCs
4  *
5  * Copyright (c) 2017 Broadcom
6  */
7 
8 /*
9  * This driver provides access to the DPFE interface of Broadcom STB SoCs.
10  * The firmware running on the DCPU inside the DDR PHY can provide current
11  * information about the system's RAM, for instance the DRAM refresh rate.
12  * This can be used as an indirect indicator for the DRAM's temperature.
13  * Slower refresh rate means cooler RAM, higher refresh rate means hotter
14  * RAM.
15  *
16  * Throughout the driver, we use readl_relaxed() and writel_relaxed(), which
17  * already contain the appropriate le32_to_cpu()/cpu_to_le32() calls.
18  *
19  * Note regarding the loading of the firmware image: we use be32_to_cpu()
20  * and le_32_to_cpu(), so we can support the following four cases:
21  *     - LE kernel + LE firmware image (the most common case)
22  *     - LE kernel + BE firmware image
23  *     - BE kernel + LE firmware image
24  *     - BE kernel + BE firmware image
25  *
26  * The DPCU always runs in big endian mode. The firmware image, however, can
27  * be in either format. Also, communication between host CPU and DCPU is
28  * always in little endian.
29  */
30 
31 #include <linux/delay.h>
32 #include <linux/firmware.h>
33 #include <linux/io.h>
34 #include <linux/module.h>
35 #include <linux/of_address.h>
36 #include <linux/of_device.h>
37 #include <linux/platform_device.h>
38 
39 #define DRVNAME			"brcmstb-dpfe"
40 
41 /* DCPU register offsets */
42 #define REG_DCPU_RESET		0x0
43 #define REG_TO_DCPU_MBOX	0x10
44 #define REG_TO_HOST_MBOX	0x14
45 
46 /* Macros to process offsets returned by the DCPU */
47 #define DRAM_MSG_ADDR_OFFSET	0x0
48 #define DRAM_MSG_TYPE_OFFSET	0x1c
49 #define DRAM_MSG_ADDR_MASK	((1UL << DRAM_MSG_TYPE_OFFSET) - 1)
50 #define DRAM_MSG_TYPE_MASK	((1UL << \
51 				 (BITS_PER_LONG - DRAM_MSG_TYPE_OFFSET)) - 1)
52 
53 /* Message RAM */
54 #define DCPU_MSG_RAM_START	0x100
55 #define DCPU_MSG_RAM(x)		(DCPU_MSG_RAM_START + (x) * sizeof(u32))
56 
57 /* DRAM Info Offsets & Masks */
58 #define DRAM_INFO_INTERVAL	0x0
59 #define DRAM_INFO_MR4		0x4
60 #define DRAM_INFO_ERROR		0x8
61 #define DRAM_INFO_MR4_MASK	0xff
62 #define DRAM_INFO_MR4_SHIFT	24	/* We need to look at byte 3 */
63 
64 /* DRAM MR4 Offsets & Masks */
65 #define DRAM_MR4_REFRESH	0x0	/* Refresh rate */
66 #define DRAM_MR4_SR_ABORT	0x3	/* Self Refresh Abort */
67 #define DRAM_MR4_PPRE		0x4	/* Post-package repair entry/exit */
68 #define DRAM_MR4_TH_OFFS	0x5	/* Thermal Offset; vendor specific */
69 #define DRAM_MR4_TUF		0x7	/* Temperature Update Flag */
70 
71 #define DRAM_MR4_REFRESH_MASK	0x7
72 #define DRAM_MR4_SR_ABORT_MASK	0x1
73 #define DRAM_MR4_PPRE_MASK	0x1
74 #define DRAM_MR4_TH_OFFS_MASK	0x3
75 #define DRAM_MR4_TUF_MASK	0x1
76 
77 /* DRAM Vendor Offsets & Masks (API v2) */
78 #define DRAM_VENDOR_MR5		0x0
79 #define DRAM_VENDOR_MR6		0x4
80 #define DRAM_VENDOR_MR7		0x8
81 #define DRAM_VENDOR_MR8		0xc
82 #define DRAM_VENDOR_ERROR	0x10
83 #define DRAM_VENDOR_MASK	0xff
84 #define DRAM_VENDOR_SHIFT	24	/* We need to look at byte 3 */
85 
86 /* DRAM Information Offsets & Masks (API v3) */
87 #define DRAM_DDR_INFO_MR4	0x0
88 #define DRAM_DDR_INFO_MR5	0x4
89 #define DRAM_DDR_INFO_MR6	0x8
90 #define DRAM_DDR_INFO_MR7	0xc
91 #define DRAM_DDR_INFO_MR8	0x10
92 #define DRAM_DDR_INFO_ERROR	0x14
93 #define DRAM_DDR_INFO_MASK	0xff
94 
95 /* Reset register bits & masks */
96 #define DCPU_RESET_SHIFT	0x0
97 #define DCPU_RESET_MASK		0x1
98 #define DCPU_CLK_DISABLE_SHIFT	0x2
99 
100 /* DCPU return codes */
101 #define DCPU_RET_ERROR_BIT	BIT(31)
102 #define DCPU_RET_SUCCESS	0x1
103 #define DCPU_RET_ERR_HEADER	(DCPU_RET_ERROR_BIT | BIT(0))
104 #define DCPU_RET_ERR_INVAL	(DCPU_RET_ERROR_BIT | BIT(1))
105 #define DCPU_RET_ERR_CHKSUM	(DCPU_RET_ERROR_BIT | BIT(2))
106 #define DCPU_RET_ERR_COMMAND	(DCPU_RET_ERROR_BIT | BIT(3))
107 /* This error code is not firmware defined and only used in the driver. */
108 #define DCPU_RET_ERR_TIMEDOUT	(DCPU_RET_ERROR_BIT | BIT(4))
109 
110 /* Firmware magic */
111 #define DPFE_BE_MAGIC		0xfe1010fe
112 #define DPFE_LE_MAGIC		0xfe0101fe
113 
114 /* Error codes */
115 #define ERR_INVALID_MAGIC	-1
116 #define ERR_INVALID_SIZE	-2
117 #define ERR_INVALID_CHKSUM	-3
118 
119 /* Message types */
120 #define DPFE_MSG_TYPE_COMMAND	1
121 #define DPFE_MSG_TYPE_RESPONSE	2
122 
123 #define DELAY_LOOP_MAX		1000
124 
125 enum dpfe_msg_fields {
126 	MSG_HEADER,
127 	MSG_COMMAND,
128 	MSG_ARG_COUNT,
129 	MSG_ARG0,
130 	MSG_FIELD_MAX	= 16 /* Max number of arguments */
131 };
132 
133 enum dpfe_commands {
134 	DPFE_CMD_GET_INFO,
135 	DPFE_CMD_GET_REFRESH,
136 	DPFE_CMD_GET_VENDOR,
137 	DPFE_CMD_MAX /* Last entry */
138 };
139 
140 /*
141  * Format of the binary firmware file:
142  *
143  *   entry
144  *      0    header
145  *              value:  0xfe0101fe  <== little endian
146  *                      0xfe1010fe  <== big endian
147  *      1    sequence:
148  *              [31:16] total segments on this build
149  *              [15:0]  this segment sequence.
150  *      2    FW version
151  *      3    IMEM byte size
152  *      4    DMEM byte size
153  *           IMEM
154  *           DMEM
155  *      last checksum ==> sum of everything
156  */
157 struct dpfe_firmware_header {
158 	u32 magic;
159 	u32 sequence;
160 	u32 version;
161 	u32 imem_size;
162 	u32 dmem_size;
163 };
164 
165 /* Things we only need during initialization. */
166 struct init_data {
167 	unsigned int dmem_len;
168 	unsigned int imem_len;
169 	unsigned int chksum;
170 	bool is_big_endian;
171 };
172 
173 /* API version and corresponding commands */
174 struct dpfe_api {
175 	int version;
176 	const char *fw_name;
177 	const struct attribute_group **sysfs_attrs;
178 	u32 command[DPFE_CMD_MAX][MSG_FIELD_MAX];
179 };
180 
181 /* Things we need for as long as we are active. */
182 struct brcmstb_dpfe_priv {
183 	void __iomem *regs;
184 	void __iomem *dmem;
185 	void __iomem *imem;
186 	struct device *dev;
187 	const struct dpfe_api *dpfe_api;
188 	struct mutex lock;
189 };
190 
191 /*
192  * Forward declaration of our sysfs attribute functions, so we can declare the
193  * attribute data structures early.
194  */
195 static ssize_t show_info(struct device *, struct device_attribute *, char *);
196 static ssize_t show_refresh(struct device *, struct device_attribute *, char *);
197 static ssize_t store_refresh(struct device *, struct device_attribute *,
198 			  const char *, size_t);
199 static ssize_t show_vendor(struct device *, struct device_attribute *, char *);
200 static ssize_t show_dram(struct device *, struct device_attribute *, char *);
201 
202 /*
203  * Declare our attributes early, so they can be referenced in the API data
204  * structure. We need to do this, because the attributes depend on the API
205  * version.
206  */
207 static DEVICE_ATTR(dpfe_info, 0444, show_info, NULL);
208 static DEVICE_ATTR(dpfe_refresh, 0644, show_refresh, store_refresh);
209 static DEVICE_ATTR(dpfe_vendor, 0444, show_vendor, NULL);
210 static DEVICE_ATTR(dpfe_dram, 0444, show_dram, NULL);
211 
212 /* API v2 sysfs attributes */
213 static struct attribute *dpfe_v2_attrs[] = {
214 	&dev_attr_dpfe_info.attr,
215 	&dev_attr_dpfe_refresh.attr,
216 	&dev_attr_dpfe_vendor.attr,
217 	NULL
218 };
219 ATTRIBUTE_GROUPS(dpfe_v2);
220 
221 /* API v3 sysfs attributes */
222 static struct attribute *dpfe_v3_attrs[] = {
223 	&dev_attr_dpfe_info.attr,
224 	&dev_attr_dpfe_dram.attr,
225 	NULL
226 };
227 ATTRIBUTE_GROUPS(dpfe_v3);
228 
229 /*
230  * Old API v2 firmware commands, as defined in the rev 0.61 specification, we
231  * use a version set to 1 to denote that it is not compatible with the new API
232  * v2 and onwards.
233  */
234 static const struct dpfe_api dpfe_api_old_v2 = {
235 	.version = 1,
236 	.fw_name = "dpfe.bin",
237 	.sysfs_attrs = dpfe_v2_groups,
238 	.command = {
239 		[DPFE_CMD_GET_INFO] = {
240 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
241 			[MSG_COMMAND] = 1,
242 			[MSG_ARG_COUNT] = 1,
243 			[MSG_ARG0] = 1,
244 		},
245 		[DPFE_CMD_GET_REFRESH] = {
246 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
247 			[MSG_COMMAND] = 2,
248 			[MSG_ARG_COUNT] = 1,
249 			[MSG_ARG0] = 1,
250 		},
251 		[DPFE_CMD_GET_VENDOR] = {
252 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
253 			[MSG_COMMAND] = 2,
254 			[MSG_ARG_COUNT] = 1,
255 			[MSG_ARG0] = 2,
256 		},
257 	}
258 };
259 
260 /*
261  * API v2 firmware commands, as defined in the rev 0.8 specification, named new
262  * v2 here
263  */
264 static const struct dpfe_api dpfe_api_new_v2 = {
265 	.version = 2,
266 	.fw_name = NULL, /* We expect the firmware to have been downloaded! */
267 	.sysfs_attrs = dpfe_v2_groups,
268 	.command = {
269 		[DPFE_CMD_GET_INFO] = {
270 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
271 			[MSG_COMMAND] = 0x101,
272 		},
273 		[DPFE_CMD_GET_REFRESH] = {
274 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
275 			[MSG_COMMAND] = 0x201,
276 		},
277 		[DPFE_CMD_GET_VENDOR] = {
278 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
279 			[MSG_COMMAND] = 0x202,
280 		},
281 	}
282 };
283 
284 /* API v3 firmware commands */
285 static const struct dpfe_api dpfe_api_v3 = {
286 	.version = 3,
287 	.fw_name = NULL, /* We expect the firmware to have been downloaded! */
288 	.sysfs_attrs = dpfe_v3_groups,
289 	.command = {
290 		[DPFE_CMD_GET_INFO] = {
291 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
292 			[MSG_COMMAND] = 0x0101,
293 			[MSG_ARG_COUNT] = 1,
294 			[MSG_ARG0] = 1,
295 		},
296 		[DPFE_CMD_GET_REFRESH] = {
297 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
298 			[MSG_COMMAND] = 0x0202,
299 			[MSG_ARG_COUNT] = 0,
300 		},
301 		/* There's no GET_VENDOR command in API v3. */
302 	},
303 };
304 
305 static const char *get_error_text(unsigned int i)
306 {
307 	static const char * const error_text[] = {
308 		"Success", "Header code incorrect",
309 		"Unknown command or argument", "Incorrect checksum",
310 		"Malformed command", "Timed out", "Unknown error",
311 	};
312 
313 	if (unlikely(i >= ARRAY_SIZE(error_text)))
314 		i = ARRAY_SIZE(error_text) - 1;
315 
316 	return error_text[i];
317 }
318 
319 static bool is_dcpu_enabled(struct brcmstb_dpfe_priv *priv)
320 {
321 	u32 val;
322 
323 	mutex_lock(&priv->lock);
324 	val = readl_relaxed(priv->regs + REG_DCPU_RESET);
325 	mutex_unlock(&priv->lock);
326 
327 	return !(val & DCPU_RESET_MASK);
328 }
329 
330 static void __disable_dcpu(struct brcmstb_dpfe_priv *priv)
331 {
332 	u32 val;
333 
334 	if (!is_dcpu_enabled(priv))
335 		return;
336 
337 	mutex_lock(&priv->lock);
338 
339 	/* Put DCPU in reset if it's running. */
340 	val = readl_relaxed(priv->regs + REG_DCPU_RESET);
341 	val |= (1 << DCPU_RESET_SHIFT);
342 	writel_relaxed(val, priv->regs + REG_DCPU_RESET);
343 
344 	mutex_unlock(&priv->lock);
345 }
346 
347 static void __enable_dcpu(struct brcmstb_dpfe_priv *priv)
348 {
349 	void __iomem *regs = priv->regs;
350 	u32 val;
351 
352 	mutex_lock(&priv->lock);
353 
354 	/* Clear mailbox registers. */
355 	writel_relaxed(0, regs + REG_TO_DCPU_MBOX);
356 	writel_relaxed(0, regs + REG_TO_HOST_MBOX);
357 
358 	/* Disable DCPU clock gating */
359 	val = readl_relaxed(regs + REG_DCPU_RESET);
360 	val &= ~(1 << DCPU_CLK_DISABLE_SHIFT);
361 	writel_relaxed(val, regs + REG_DCPU_RESET);
362 
363 	/* Take DCPU out of reset */
364 	val = readl_relaxed(regs + REG_DCPU_RESET);
365 	val &= ~(1 << DCPU_RESET_SHIFT);
366 	writel_relaxed(val, regs + REG_DCPU_RESET);
367 
368 	mutex_unlock(&priv->lock);
369 }
370 
371 static unsigned int get_msg_chksum(const u32 msg[], unsigned int max)
372 {
373 	unsigned int sum = 0;
374 	unsigned int i;
375 
376 	/* Don't include the last field in the checksum. */
377 	for (i = 0; i < max; i++)
378 		sum += msg[i];
379 
380 	return sum;
381 }
382 
383 static void __iomem *get_msg_ptr(struct brcmstb_dpfe_priv *priv, u32 response,
384 				 char *buf, ssize_t *size)
385 {
386 	unsigned int msg_type;
387 	unsigned int offset;
388 	void __iomem *ptr = NULL;
389 
390 	/* There is no need to use this function for API v3 or later. */
391 	if (unlikely(priv->dpfe_api->version >= 3))
392 		return NULL;
393 
394 	msg_type = (response >> DRAM_MSG_TYPE_OFFSET) & DRAM_MSG_TYPE_MASK;
395 	offset = (response >> DRAM_MSG_ADDR_OFFSET) & DRAM_MSG_ADDR_MASK;
396 
397 	/*
398 	 * msg_type == 1: the offset is relative to the message RAM
399 	 * msg_type == 0: the offset is relative to the data RAM (this is the
400 	 *                previous way of passing data)
401 	 * msg_type is anything else: there's critical hardware problem
402 	 */
403 	switch (msg_type) {
404 	case 1:
405 		ptr = priv->regs + DCPU_MSG_RAM_START + offset;
406 		break;
407 	case 0:
408 		ptr = priv->dmem + offset;
409 		break;
410 	default:
411 		dev_emerg(priv->dev, "invalid message reply from DCPU: %#x\n",
412 			response);
413 		if (buf && size)
414 			*size = sprintf(buf,
415 				"FATAL: communication error with DCPU\n");
416 	}
417 
418 	return ptr;
419 }
420 
421 static void __finalize_command(struct brcmstb_dpfe_priv *priv)
422 {
423 	unsigned int release_mbox;
424 
425 	/*
426 	 * It depends on the API version which MBOX register we have to write to
427 	 * to signal we are done.
428 	 */
429 	release_mbox = (priv->dpfe_api->version < 2)
430 			? REG_TO_HOST_MBOX : REG_TO_DCPU_MBOX;
431 	writel_relaxed(0, priv->regs + release_mbox);
432 }
433 
434 static int __send_command(struct brcmstb_dpfe_priv *priv, unsigned int cmd,
435 			  u32 result[])
436 {
437 	const u32 *msg = priv->dpfe_api->command[cmd];
438 	void __iomem *regs = priv->regs;
439 	unsigned int i, chksum, chksum_idx;
440 	int ret = 0;
441 	u32 resp;
442 
443 	if (cmd >= DPFE_CMD_MAX)
444 		return -1;
445 
446 	mutex_lock(&priv->lock);
447 
448 	/* Wait for DCPU to become ready */
449 	for (i = 0; i < DELAY_LOOP_MAX; i++) {
450 		resp = readl_relaxed(regs + REG_TO_HOST_MBOX);
451 		if (resp == 0)
452 			break;
453 		msleep(1);
454 	}
455 	if (resp != 0) {
456 		mutex_unlock(&priv->lock);
457 		return -ffs(DCPU_RET_ERR_TIMEDOUT);
458 	}
459 
460 	/* Compute checksum over the message */
461 	chksum_idx = msg[MSG_ARG_COUNT] + MSG_ARG_COUNT + 1;
462 	chksum = get_msg_chksum(msg, chksum_idx);
463 
464 	/* Write command and arguments to message area */
465 	for (i = 0; i < MSG_FIELD_MAX; i++) {
466 		if (i == chksum_idx)
467 			writel_relaxed(chksum, regs + DCPU_MSG_RAM(i));
468 		else
469 			writel_relaxed(msg[i], regs + DCPU_MSG_RAM(i));
470 	}
471 
472 	/* Tell DCPU there is a command waiting */
473 	writel_relaxed(1, regs + REG_TO_DCPU_MBOX);
474 
475 	/* Wait for DCPU to process the command */
476 	for (i = 0; i < DELAY_LOOP_MAX; i++) {
477 		/* Read response code */
478 		resp = readl_relaxed(regs + REG_TO_HOST_MBOX);
479 		if (resp > 0)
480 			break;
481 		msleep(1);
482 	}
483 
484 	if (i == DELAY_LOOP_MAX) {
485 		resp = (DCPU_RET_ERR_TIMEDOUT & ~DCPU_RET_ERROR_BIT);
486 		ret = -ffs(resp);
487 	} else {
488 		/* Read response data */
489 		for (i = 0; i < MSG_FIELD_MAX; i++)
490 			result[i] = readl_relaxed(regs + DCPU_MSG_RAM(i));
491 		chksum_idx = result[MSG_ARG_COUNT] + MSG_ARG_COUNT + 1;
492 	}
493 
494 	/* Tell DCPU we are done */
495 	__finalize_command(priv);
496 
497 	mutex_unlock(&priv->lock);
498 
499 	if (ret)
500 		return ret;
501 
502 	/* Verify response */
503 	chksum = get_msg_chksum(result, chksum_idx);
504 	if (chksum != result[chksum_idx])
505 		resp = DCPU_RET_ERR_CHKSUM;
506 
507 	if (resp != DCPU_RET_SUCCESS) {
508 		resp &= ~DCPU_RET_ERROR_BIT;
509 		ret = -ffs(resp);
510 	}
511 
512 	return ret;
513 }
514 
515 /* Ensure that the firmware file loaded meets all the requirements. */
516 static int __verify_firmware(struct init_data *init,
517 			     const struct firmware *fw)
518 {
519 	const struct dpfe_firmware_header *header = (void *)fw->data;
520 	unsigned int dmem_size, imem_size, total_size;
521 	bool is_big_endian = false;
522 	const u32 *chksum_ptr;
523 
524 	if (header->magic == DPFE_BE_MAGIC)
525 		is_big_endian = true;
526 	else if (header->magic != DPFE_LE_MAGIC)
527 		return ERR_INVALID_MAGIC;
528 
529 	if (is_big_endian) {
530 		dmem_size = be32_to_cpu(header->dmem_size);
531 		imem_size = be32_to_cpu(header->imem_size);
532 	} else {
533 		dmem_size = le32_to_cpu(header->dmem_size);
534 		imem_size = le32_to_cpu(header->imem_size);
535 	}
536 
537 	/* Data and instruction sections are 32 bit words. */
538 	if ((dmem_size % sizeof(u32)) != 0 || (imem_size % sizeof(u32)) != 0)
539 		return ERR_INVALID_SIZE;
540 
541 	/*
542 	 * The header + the data section + the instruction section + the
543 	 * checksum must be equal to the total firmware size.
544 	 */
545 	total_size = dmem_size + imem_size + sizeof(*header) +
546 		sizeof(*chksum_ptr);
547 	if (total_size != fw->size)
548 		return ERR_INVALID_SIZE;
549 
550 	/* The checksum comes at the very end. */
551 	chksum_ptr = (void *)fw->data + sizeof(*header) + dmem_size + imem_size;
552 
553 	init->is_big_endian = is_big_endian;
554 	init->dmem_len = dmem_size;
555 	init->imem_len = imem_size;
556 	init->chksum = (is_big_endian)
557 		? be32_to_cpu(*chksum_ptr) : le32_to_cpu(*chksum_ptr);
558 
559 	return 0;
560 }
561 
562 /* Verify checksum by reading back the firmware from co-processor RAM. */
563 static int __verify_fw_checksum(struct init_data *init,
564 				struct brcmstb_dpfe_priv *priv,
565 				const struct dpfe_firmware_header *header,
566 				u32 checksum)
567 {
568 	u32 magic, sequence, version, sum;
569 	u32 __iomem *dmem = priv->dmem;
570 	u32 __iomem *imem = priv->imem;
571 	unsigned int i;
572 
573 	if (init->is_big_endian) {
574 		magic = be32_to_cpu(header->magic);
575 		sequence = be32_to_cpu(header->sequence);
576 		version = be32_to_cpu(header->version);
577 	} else {
578 		magic = le32_to_cpu(header->magic);
579 		sequence = le32_to_cpu(header->sequence);
580 		version = le32_to_cpu(header->version);
581 	}
582 
583 	sum = magic + sequence + version + init->dmem_len + init->imem_len;
584 
585 	for (i = 0; i < init->dmem_len / sizeof(u32); i++)
586 		sum += readl_relaxed(dmem + i);
587 
588 	for (i = 0; i < init->imem_len / sizeof(u32); i++)
589 		sum += readl_relaxed(imem + i);
590 
591 	return (sum == checksum) ? 0 : -1;
592 }
593 
594 static int __write_firmware(u32 __iomem *mem, const u32 *fw,
595 			    unsigned int size, bool is_big_endian)
596 {
597 	unsigned int i;
598 
599 	/* Convert size to 32-bit words. */
600 	size /= sizeof(u32);
601 
602 	/* It is recommended to clear the firmware area first. */
603 	for (i = 0; i < size; i++)
604 		writel_relaxed(0, mem + i);
605 
606 	/* Now copy it. */
607 	if (is_big_endian) {
608 		for (i = 0; i < size; i++)
609 			writel_relaxed(be32_to_cpu(fw[i]), mem + i);
610 	} else {
611 		for (i = 0; i < size; i++)
612 			writel_relaxed(le32_to_cpu(fw[i]), mem + i);
613 	}
614 
615 	return 0;
616 }
617 
618 static int brcmstb_dpfe_download_firmware(struct brcmstb_dpfe_priv *priv)
619 {
620 	const struct dpfe_firmware_header *header;
621 	unsigned int dmem_size, imem_size;
622 	struct device *dev = priv->dev;
623 	bool is_big_endian = false;
624 	const struct firmware *fw;
625 	const u32 *dmem, *imem;
626 	struct init_data init;
627 	const void *fw_blob;
628 	int ret;
629 
630 	/*
631 	 * Skip downloading the firmware if the DCPU is already running and
632 	 * responding to commands.
633 	 */
634 	if (is_dcpu_enabled(priv)) {
635 		u32 response[MSG_FIELD_MAX];
636 
637 		ret = __send_command(priv, DPFE_CMD_GET_INFO, response);
638 		if (!ret)
639 			return 0;
640 	}
641 
642 	/*
643 	 * If the firmware filename is NULL it means the boot firmware has to
644 	 * download the DCPU firmware for us. If that didn't work, we have to
645 	 * bail, since downloading it ourselves wouldn't work either.
646 	 */
647 	if (!priv->dpfe_api->fw_name)
648 		return -ENODEV;
649 
650 	ret = firmware_request_nowarn(&fw, priv->dpfe_api->fw_name, dev);
651 	/*
652 	 * Defer the firmware download if the firmware file couldn't be found.
653 	 * The root file system may not be available yet.
654 	 */
655 	if (ret)
656 		return (ret == -ENOENT) ? -EPROBE_DEFER : ret;
657 
658 	ret = __verify_firmware(&init, fw);
659 	if (ret) {
660 		ret = -EFAULT;
661 		goto release_fw;
662 	}
663 
664 	__disable_dcpu(priv);
665 
666 	is_big_endian = init.is_big_endian;
667 	dmem_size = init.dmem_len;
668 	imem_size = init.imem_len;
669 
670 	/* At the beginning of the firmware blob is a header. */
671 	header = (struct dpfe_firmware_header *)fw->data;
672 	/* Void pointer to the beginning of the actual firmware. */
673 	fw_blob = fw->data + sizeof(*header);
674 	/* IMEM comes right after the header. */
675 	imem = fw_blob;
676 	/* DMEM follows after IMEM. */
677 	dmem = fw_blob + imem_size;
678 
679 	ret = __write_firmware(priv->dmem, dmem, dmem_size, is_big_endian);
680 	if (ret)
681 		goto release_fw;
682 	ret = __write_firmware(priv->imem, imem, imem_size, is_big_endian);
683 	if (ret)
684 		goto release_fw;
685 
686 	ret = __verify_fw_checksum(&init, priv, header, init.chksum);
687 	if (ret)
688 		goto release_fw;
689 
690 	__enable_dcpu(priv);
691 
692 release_fw:
693 	release_firmware(fw);
694 	return ret;
695 }
696 
697 static ssize_t generic_show(unsigned int command, u32 response[],
698 			    struct brcmstb_dpfe_priv *priv, char *buf)
699 {
700 	int ret;
701 
702 	if (!priv)
703 		return sprintf(buf, "ERROR: driver private data not set\n");
704 
705 	ret = __send_command(priv, command, response);
706 	if (ret < 0)
707 		return sprintf(buf, "ERROR: %s\n", get_error_text(-ret));
708 
709 	return 0;
710 }
711 
712 static ssize_t show_info(struct device *dev, struct device_attribute *devattr,
713 			 char *buf)
714 {
715 	u32 response[MSG_FIELD_MAX];
716 	struct brcmstb_dpfe_priv *priv;
717 	unsigned int info;
718 	ssize_t ret;
719 
720 	priv = dev_get_drvdata(dev);
721 	ret = generic_show(DPFE_CMD_GET_INFO, response, priv, buf);
722 	if (ret)
723 		return ret;
724 
725 	info = response[MSG_ARG0];
726 
727 	return sprintf(buf, "%u.%u.%u.%u\n",
728 		       (info >> 24) & 0xff,
729 		       (info >> 16) & 0xff,
730 		       (info >> 8) & 0xff,
731 		       info & 0xff);
732 }
733 
734 static ssize_t show_refresh(struct device *dev,
735 			    struct device_attribute *devattr, char *buf)
736 {
737 	u32 response[MSG_FIELD_MAX];
738 	void __iomem *info;
739 	struct brcmstb_dpfe_priv *priv;
740 	u8 refresh, sr_abort, ppre, thermal_offs, tuf;
741 	u32 mr4;
742 	ssize_t ret;
743 
744 	priv = dev_get_drvdata(dev);
745 	ret = generic_show(DPFE_CMD_GET_REFRESH, response, priv, buf);
746 	if (ret)
747 		return ret;
748 
749 	info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
750 	if (!info)
751 		return ret;
752 
753 	mr4 = (readl_relaxed(info + DRAM_INFO_MR4) >> DRAM_INFO_MR4_SHIFT) &
754 	       DRAM_INFO_MR4_MASK;
755 
756 	refresh = (mr4 >> DRAM_MR4_REFRESH) & DRAM_MR4_REFRESH_MASK;
757 	sr_abort = (mr4 >> DRAM_MR4_SR_ABORT) & DRAM_MR4_SR_ABORT_MASK;
758 	ppre = (mr4 >> DRAM_MR4_PPRE) & DRAM_MR4_PPRE_MASK;
759 	thermal_offs = (mr4 >> DRAM_MR4_TH_OFFS) & DRAM_MR4_TH_OFFS_MASK;
760 	tuf = (mr4 >> DRAM_MR4_TUF) & DRAM_MR4_TUF_MASK;
761 
762 	return sprintf(buf, "%#x %#x %#x %#x %#x %#x %#x\n",
763 		       readl_relaxed(info + DRAM_INFO_INTERVAL),
764 		       refresh, sr_abort, ppre, thermal_offs, tuf,
765 		       readl_relaxed(info + DRAM_INFO_ERROR));
766 }
767 
768 static ssize_t store_refresh(struct device *dev, struct device_attribute *attr,
769 			  const char *buf, size_t count)
770 {
771 	u32 response[MSG_FIELD_MAX];
772 	struct brcmstb_dpfe_priv *priv;
773 	void __iomem *info;
774 	unsigned long val;
775 	int ret;
776 
777 	if (kstrtoul(buf, 0, &val) < 0)
778 		return -EINVAL;
779 
780 	priv = dev_get_drvdata(dev);
781 	ret = __send_command(priv, DPFE_CMD_GET_REFRESH, response);
782 	if (ret)
783 		return ret;
784 
785 	info = get_msg_ptr(priv, response[MSG_ARG0], NULL, NULL);
786 	if (!info)
787 		return -EIO;
788 
789 	writel_relaxed(val, info + DRAM_INFO_INTERVAL);
790 
791 	return count;
792 }
793 
794 static ssize_t show_vendor(struct device *dev, struct device_attribute *devattr,
795 			   char *buf)
796 {
797 	u32 response[MSG_FIELD_MAX];
798 	struct brcmstb_dpfe_priv *priv;
799 	void __iomem *info;
800 	ssize_t ret;
801 	u32 mr5, mr6, mr7, mr8, err;
802 
803 	priv = dev_get_drvdata(dev);
804 	ret = generic_show(DPFE_CMD_GET_VENDOR, response, priv, buf);
805 	if (ret)
806 		return ret;
807 
808 	info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
809 	if (!info)
810 		return ret;
811 
812 	mr5 = (readl_relaxed(info + DRAM_VENDOR_MR5) >> DRAM_VENDOR_SHIFT) &
813 		DRAM_VENDOR_MASK;
814 	mr6 = (readl_relaxed(info + DRAM_VENDOR_MR6) >> DRAM_VENDOR_SHIFT) &
815 		DRAM_VENDOR_MASK;
816 	mr7 = (readl_relaxed(info + DRAM_VENDOR_MR7) >> DRAM_VENDOR_SHIFT) &
817 		DRAM_VENDOR_MASK;
818 	mr8 = (readl_relaxed(info + DRAM_VENDOR_MR8) >> DRAM_VENDOR_SHIFT) &
819 		DRAM_VENDOR_MASK;
820 	err = readl_relaxed(info + DRAM_VENDOR_ERROR) & DRAM_VENDOR_MASK;
821 
822 	return sprintf(buf, "%#x %#x %#x %#x %#x\n", mr5, mr6, mr7, mr8, err);
823 }
824 
825 static ssize_t show_dram(struct device *dev, struct device_attribute *devattr,
826 			 char *buf)
827 {
828 	u32 response[MSG_FIELD_MAX];
829 	struct brcmstb_dpfe_priv *priv;
830 	ssize_t ret;
831 	u32 mr4, mr5, mr6, mr7, mr8, err;
832 
833 	priv = dev_get_drvdata(dev);
834 	ret = generic_show(DPFE_CMD_GET_REFRESH, response, priv, buf);
835 	if (ret)
836 		return ret;
837 
838 	mr4 = response[MSG_ARG0 + 0] & DRAM_INFO_MR4_MASK;
839 	mr5 = response[MSG_ARG0 + 1] & DRAM_DDR_INFO_MASK;
840 	mr6 = response[MSG_ARG0 + 2] & DRAM_DDR_INFO_MASK;
841 	mr7 = response[MSG_ARG0 + 3] & DRAM_DDR_INFO_MASK;
842 	mr8 = response[MSG_ARG0 + 4] & DRAM_DDR_INFO_MASK;
843 	err = response[MSG_ARG0 + 5] & DRAM_DDR_INFO_MASK;
844 
845 	return sprintf(buf, "%#x %#x %#x %#x %#x %#x\n", mr4, mr5, mr6, mr7,
846 			mr8, err);
847 }
848 
849 static int brcmstb_dpfe_resume(struct platform_device *pdev)
850 {
851 	struct brcmstb_dpfe_priv *priv = platform_get_drvdata(pdev);
852 
853 	return brcmstb_dpfe_download_firmware(priv);
854 }
855 
856 static int brcmstb_dpfe_probe(struct platform_device *pdev)
857 {
858 	struct device *dev = &pdev->dev;
859 	struct brcmstb_dpfe_priv *priv;
860 	struct resource *res;
861 	int ret;
862 
863 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
864 	if (!priv)
865 		return -ENOMEM;
866 
867 	priv->dev = dev;
868 
869 	mutex_init(&priv->lock);
870 	platform_set_drvdata(pdev, priv);
871 
872 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-cpu");
873 	priv->regs = devm_ioremap_resource(dev, res);
874 	if (IS_ERR(priv->regs)) {
875 		dev_err(dev, "couldn't map DCPU registers\n");
876 		return -ENODEV;
877 	}
878 
879 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-dmem");
880 	priv->dmem = devm_ioremap_resource(dev, res);
881 	if (IS_ERR(priv->dmem)) {
882 		dev_err(dev, "Couldn't map DCPU data memory\n");
883 		return -ENOENT;
884 	}
885 
886 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-imem");
887 	priv->imem = devm_ioremap_resource(dev, res);
888 	if (IS_ERR(priv->imem)) {
889 		dev_err(dev, "Couldn't map DCPU instruction memory\n");
890 		return -ENOENT;
891 	}
892 
893 	priv->dpfe_api = of_device_get_match_data(dev);
894 	if (unlikely(!priv->dpfe_api)) {
895 		/*
896 		 * It should be impossible to end up here, but to be safe we
897 		 * check anyway.
898 		 */
899 		dev_err(dev, "Couldn't determine API\n");
900 		return -ENOENT;
901 	}
902 
903 	ret = brcmstb_dpfe_download_firmware(priv);
904 	if (ret)
905 		return dev_err_probe(dev, ret, "Couldn't download firmware\n");
906 
907 	ret = sysfs_create_groups(&pdev->dev.kobj, priv->dpfe_api->sysfs_attrs);
908 	if (!ret)
909 		dev_info(dev, "registered with API v%d.\n",
910 			 priv->dpfe_api->version);
911 
912 	return ret;
913 }
914 
915 static int brcmstb_dpfe_remove(struct platform_device *pdev)
916 {
917 	struct brcmstb_dpfe_priv *priv = dev_get_drvdata(&pdev->dev);
918 
919 	sysfs_remove_groups(&pdev->dev.kobj, priv->dpfe_api->sysfs_attrs);
920 
921 	return 0;
922 }
923 
924 static const struct of_device_id brcmstb_dpfe_of_match[] = {
925 	/* Use legacy API v2 for a select number of chips */
926 	{ .compatible = "brcm,bcm7268-dpfe-cpu", .data = &dpfe_api_old_v2 },
927 	{ .compatible = "brcm,bcm7271-dpfe-cpu", .data = &dpfe_api_old_v2 },
928 	{ .compatible = "brcm,bcm7278-dpfe-cpu", .data = &dpfe_api_old_v2 },
929 	{ .compatible = "brcm,bcm7211-dpfe-cpu", .data = &dpfe_api_new_v2 },
930 	/* API v3 is the default going forward */
931 	{ .compatible = "brcm,dpfe-cpu", .data = &dpfe_api_v3 },
932 	{}
933 };
934 MODULE_DEVICE_TABLE(of, brcmstb_dpfe_of_match);
935 
936 static struct platform_driver brcmstb_dpfe_driver = {
937 	.driver	= {
938 		.name = DRVNAME,
939 		.of_match_table = brcmstb_dpfe_of_match,
940 	},
941 	.probe = brcmstb_dpfe_probe,
942 	.remove	= brcmstb_dpfe_remove,
943 	.resume = brcmstb_dpfe_resume,
944 };
945 
946 module_platform_driver(brcmstb_dpfe_driver);
947 
948 MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
949 MODULE_DESCRIPTION("BRCMSTB DDR PHY Front End Driver");
950 MODULE_LICENSE("GPL");
951