xref: /openbmc/linux/drivers/memory/brcmstb_dpfe.c (revision feac8c8b)
1 /*
2  * DDR PHY Front End (DPFE) driver for Broadcom set top box SoCs
3  *
4  * Copyright (c) 2017 Broadcom
5  *
6  * Released under the GPLv2 only.
7  * SPDX-License-Identifier: GPL-2.0
8  */
9 
10 /*
11  * This driver provides access to the DPFE interface of Broadcom STB SoCs.
12  * The firmware running on the DCPU inside the DDR PHY can provide current
13  * information about the system's RAM, for instance the DRAM refresh rate.
14  * This can be used as an indirect indicator for the DRAM's temperature.
15  * Slower refresh rate means cooler RAM, higher refresh rate means hotter
16  * RAM.
17  *
18  * Throughout the driver, we use readl_relaxed() and writel_relaxed(), which
19  * already contain the appropriate le32_to_cpu()/cpu_to_le32() calls.
20  *
21  * Note regarding the loading of the firmware image: we use be32_to_cpu()
22  * and le_32_to_cpu(), so we can support the following four cases:
23  *     - LE kernel + LE firmware image (the most common case)
24  *     - LE kernel + BE firmware image
25  *     - BE kernel + LE firmware image
26  *     - BE kernel + BE firmware image
27  *
28  * The DPCU always runs in big endian mode. The firwmare image, however, can
29  * be in either format. Also, communication between host CPU and DCPU is
30  * always in little endian.
31  */
32 
33 #include <linux/delay.h>
34 #include <linux/firmware.h>
35 #include <linux/io.h>
36 #include <linux/module.h>
37 #include <linux/of_address.h>
38 #include <linux/platform_device.h>
39 
40 #define DRVNAME			"brcmstb-dpfe"
41 #define FIRMWARE_NAME		"dpfe.bin"
42 
43 /* DCPU register offsets */
44 #define REG_DCPU_RESET		0x0
45 #define REG_TO_DCPU_MBOX	0x10
46 #define REG_TO_HOST_MBOX	0x14
47 
48 /* Macros to process offsets returned by the DCPU */
49 #define DRAM_MSG_ADDR_OFFSET	0x0
50 #define DRAM_MSG_TYPE_OFFSET	0x1c
51 #define DRAM_MSG_ADDR_MASK	((1UL << DRAM_MSG_TYPE_OFFSET) - 1)
52 #define DRAM_MSG_TYPE_MASK	((1UL << \
53 				 (BITS_PER_LONG - DRAM_MSG_TYPE_OFFSET)) - 1)
54 
55 /* Message RAM */
56 #define DCPU_MSG_RAM_START	0x100
57 #define DCPU_MSG_RAM(x)		(DCPU_MSG_RAM_START + (x) * sizeof(u32))
58 
59 /* DRAM Info Offsets & Masks */
60 #define DRAM_INFO_INTERVAL	0x0
61 #define DRAM_INFO_MR4		0x4
62 #define DRAM_INFO_ERROR		0x8
63 #define DRAM_INFO_MR4_MASK	0xff
64 
65 /* DRAM MR4 Offsets & Masks */
66 #define DRAM_MR4_REFRESH	0x0	/* Refresh rate */
67 #define DRAM_MR4_SR_ABORT	0x3	/* Self Refresh Abort */
68 #define DRAM_MR4_PPRE		0x4	/* Post-package repair entry/exit */
69 #define DRAM_MR4_TH_OFFS	0x5	/* Thermal Offset; vendor specific */
70 #define DRAM_MR4_TUF		0x7	/* Temperature Update Flag */
71 
72 #define DRAM_MR4_REFRESH_MASK	0x7
73 #define DRAM_MR4_SR_ABORT_MASK	0x1
74 #define DRAM_MR4_PPRE_MASK	0x1
75 #define DRAM_MR4_TH_OFFS_MASK	0x3
76 #define DRAM_MR4_TUF_MASK	0x1
77 
78 /* DRAM Vendor Offsets & Masks */
79 #define DRAM_VENDOR_MR5		0x0
80 #define DRAM_VENDOR_MR6		0x4
81 #define DRAM_VENDOR_MR7		0x8
82 #define DRAM_VENDOR_MR8		0xc
83 #define DRAM_VENDOR_ERROR	0x10
84 #define DRAM_VENDOR_MASK	0xff
85 
86 /* Reset register bits & masks */
87 #define DCPU_RESET_SHIFT	0x0
88 #define DCPU_RESET_MASK		0x1
89 #define DCPU_CLK_DISABLE_SHIFT	0x2
90 
91 /* DCPU return codes */
92 #define DCPU_RET_ERROR_BIT	BIT(31)
93 #define DCPU_RET_SUCCESS	0x1
94 #define DCPU_RET_ERR_HEADER	(DCPU_RET_ERROR_BIT | BIT(0))
95 #define DCPU_RET_ERR_INVAL	(DCPU_RET_ERROR_BIT | BIT(1))
96 #define DCPU_RET_ERR_CHKSUM	(DCPU_RET_ERROR_BIT | BIT(2))
97 #define DCPU_RET_ERR_COMMAND	(DCPU_RET_ERROR_BIT | BIT(3))
98 /* This error code is not firmware defined and only used in the driver. */
99 #define DCPU_RET_ERR_TIMEDOUT	(DCPU_RET_ERROR_BIT | BIT(4))
100 
101 /* Firmware magic */
102 #define DPFE_BE_MAGIC		0xfe1010fe
103 #define DPFE_LE_MAGIC		0xfe0101fe
104 
105 /* Error codes */
106 #define ERR_INVALID_MAGIC	-1
107 #define ERR_INVALID_SIZE	-2
108 #define ERR_INVALID_CHKSUM	-3
109 
110 /* Message types */
111 #define DPFE_MSG_TYPE_COMMAND	1
112 #define DPFE_MSG_TYPE_RESPONSE	2
113 
114 #define DELAY_LOOP_MAX		200000
115 
116 enum dpfe_msg_fields {
117 	MSG_HEADER,
118 	MSG_COMMAND,
119 	MSG_ARG_COUNT,
120 	MSG_ARG0,
121 	MSG_CHKSUM,
122 	MSG_FIELD_MAX /* Last entry */
123 };
124 
125 enum dpfe_commands {
126 	DPFE_CMD_GET_INFO,
127 	DPFE_CMD_GET_REFRESH,
128 	DPFE_CMD_GET_VENDOR,
129 	DPFE_CMD_MAX /* Last entry */
130 };
131 
132 struct dpfe_msg {
133 	u32 header;
134 	u32 command;
135 	u32 arg_count;
136 	u32 arg0;
137 	u32 chksum; /* This is the sum of all other entries. */
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 /* Things we need for as long as we are active. */
174 struct private_data {
175 	void __iomem *regs;
176 	void __iomem *dmem;
177 	void __iomem *imem;
178 	struct device *dev;
179 	unsigned int index;
180 	struct mutex lock;
181 };
182 
183 static const char *error_text[] = {
184 	"Success", "Header code incorrect", "Unknown command or argument",
185 	"Incorrect checksum", "Malformed command", "Timed out",
186 };
187 
188 /* List of supported firmware commands */
189 static const u32 dpfe_commands[DPFE_CMD_MAX][MSG_FIELD_MAX] = {
190 	[DPFE_CMD_GET_INFO] = {
191 		[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
192 		[MSG_COMMAND] = 1,
193 		[MSG_ARG_COUNT] = 1,
194 		[MSG_ARG0] = 1,
195 		[MSG_CHKSUM] = 4,
196 	},
197 	[DPFE_CMD_GET_REFRESH] = {
198 		[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
199 		[MSG_COMMAND] = 2,
200 		[MSG_ARG_COUNT] = 1,
201 		[MSG_ARG0] = 1,
202 		[MSG_CHKSUM] = 5,
203 	},
204 	[DPFE_CMD_GET_VENDOR] = {
205 		[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
206 		[MSG_COMMAND] = 2,
207 		[MSG_ARG_COUNT] = 1,
208 		[MSG_ARG0] = 2,
209 		[MSG_CHKSUM] = 6,
210 	},
211 };
212 
213 static bool is_dcpu_enabled(void __iomem *regs)
214 {
215 	u32 val;
216 
217 	val = readl_relaxed(regs + REG_DCPU_RESET);
218 
219 	return !(val & DCPU_RESET_MASK);
220 }
221 
222 static void __disable_dcpu(void __iomem *regs)
223 {
224 	u32 val;
225 
226 	if (!is_dcpu_enabled(regs))
227 		return;
228 
229 	/* Put DCPU in reset if it's running. */
230 	val = readl_relaxed(regs + REG_DCPU_RESET);
231 	val |= (1 << DCPU_RESET_SHIFT);
232 	writel_relaxed(val, regs + REG_DCPU_RESET);
233 }
234 
235 static void __enable_dcpu(void __iomem *regs)
236 {
237 	u32 val;
238 
239 	/* Clear mailbox registers. */
240 	writel_relaxed(0, regs + REG_TO_DCPU_MBOX);
241 	writel_relaxed(0, regs + REG_TO_HOST_MBOX);
242 
243 	/* Disable DCPU clock gating */
244 	val = readl_relaxed(regs + REG_DCPU_RESET);
245 	val &= ~(1 << DCPU_CLK_DISABLE_SHIFT);
246 	writel_relaxed(val, regs + REG_DCPU_RESET);
247 
248 	/* Take DCPU out of reset */
249 	val = readl_relaxed(regs + REG_DCPU_RESET);
250 	val &= ~(1 << DCPU_RESET_SHIFT);
251 	writel_relaxed(val, regs + REG_DCPU_RESET);
252 }
253 
254 static unsigned int get_msg_chksum(const u32 msg[])
255 {
256 	unsigned int sum = 0;
257 	unsigned int i;
258 
259 	/* Don't include the last field in the checksum. */
260 	for (i = 0; i < MSG_FIELD_MAX - 1; i++)
261 		sum += msg[i];
262 
263 	return sum;
264 }
265 
266 static void __iomem *get_msg_ptr(struct private_data *priv, u32 response,
267 				 char *buf, ssize_t *size)
268 {
269 	unsigned int msg_type;
270 	unsigned int offset;
271 	void __iomem *ptr = NULL;
272 
273 	msg_type = (response >> DRAM_MSG_TYPE_OFFSET) & DRAM_MSG_TYPE_MASK;
274 	offset = (response >> DRAM_MSG_ADDR_OFFSET) & DRAM_MSG_ADDR_MASK;
275 
276 	/*
277 	 * msg_type == 1: the offset is relative to the message RAM
278 	 * msg_type == 0: the offset is relative to the data RAM (this is the
279 	 *                previous way of passing data)
280 	 * msg_type is anything else: there's critical hardware problem
281 	 */
282 	switch (msg_type) {
283 	case 1:
284 		ptr = priv->regs + DCPU_MSG_RAM_START + offset;
285 		break;
286 	case 0:
287 		ptr = priv->dmem + offset;
288 		break;
289 	default:
290 		dev_emerg(priv->dev, "invalid message reply from DCPU: %#x\n",
291 			response);
292 		if (buf && size)
293 			*size = sprintf(buf,
294 				"FATAL: communication error with DCPU\n");
295 	}
296 
297 	return ptr;
298 }
299 
300 static int __send_command(struct private_data *priv, unsigned int cmd,
301 			  u32 result[])
302 {
303 	const u32 *msg = dpfe_commands[cmd];
304 	void __iomem *regs = priv->regs;
305 	unsigned int i, chksum;
306 	int ret = 0;
307 	u32 resp;
308 
309 	if (cmd >= DPFE_CMD_MAX)
310 		return -1;
311 
312 	mutex_lock(&priv->lock);
313 
314 	/* Write command and arguments to message area */
315 	for (i = 0; i < MSG_FIELD_MAX; i++)
316 		writel_relaxed(msg[i], regs + DCPU_MSG_RAM(i));
317 
318 	/* Tell DCPU there is a command waiting */
319 	writel_relaxed(1, regs + REG_TO_DCPU_MBOX);
320 
321 	/* Wait for DCPU to process the command */
322 	for (i = 0; i < DELAY_LOOP_MAX; i++) {
323 		/* Read response code */
324 		resp = readl_relaxed(regs + REG_TO_HOST_MBOX);
325 		if (resp > 0)
326 			break;
327 		udelay(5);
328 	}
329 
330 	if (i == DELAY_LOOP_MAX) {
331 		resp = (DCPU_RET_ERR_TIMEDOUT & ~DCPU_RET_ERROR_BIT);
332 		ret = -ffs(resp);
333 	} else {
334 		/* Read response data */
335 		for (i = 0; i < MSG_FIELD_MAX; i++)
336 			result[i] = readl_relaxed(regs + DCPU_MSG_RAM(i));
337 	}
338 
339 	/* Tell DCPU we are done */
340 	writel_relaxed(0, regs + REG_TO_HOST_MBOX);
341 
342 	mutex_unlock(&priv->lock);
343 
344 	if (ret)
345 		return ret;
346 
347 	/* Verify response */
348 	chksum = get_msg_chksum(result);
349 	if (chksum != result[MSG_CHKSUM])
350 		resp = DCPU_RET_ERR_CHKSUM;
351 
352 	if (resp != DCPU_RET_SUCCESS) {
353 		resp &= ~DCPU_RET_ERROR_BIT;
354 		ret = -ffs(resp);
355 	}
356 
357 	return ret;
358 }
359 
360 /* Ensure that the firmware file loaded meets all the requirements. */
361 static int __verify_firmware(struct init_data *init,
362 			     const struct firmware *fw)
363 {
364 	const struct dpfe_firmware_header *header = (void *)fw->data;
365 	unsigned int dmem_size, imem_size, total_size;
366 	bool is_big_endian = false;
367 	const u32 *chksum_ptr;
368 
369 	if (header->magic == DPFE_BE_MAGIC)
370 		is_big_endian = true;
371 	else if (header->magic != DPFE_LE_MAGIC)
372 		return ERR_INVALID_MAGIC;
373 
374 	if (is_big_endian) {
375 		dmem_size = be32_to_cpu(header->dmem_size);
376 		imem_size = be32_to_cpu(header->imem_size);
377 	} else {
378 		dmem_size = le32_to_cpu(header->dmem_size);
379 		imem_size = le32_to_cpu(header->imem_size);
380 	}
381 
382 	/* Data and instruction sections are 32 bit words. */
383 	if ((dmem_size % sizeof(u32)) != 0 || (imem_size % sizeof(u32)) != 0)
384 		return ERR_INVALID_SIZE;
385 
386 	/*
387 	 * The header + the data section + the instruction section + the
388 	 * checksum must be equal to the total firmware size.
389 	 */
390 	total_size = dmem_size + imem_size + sizeof(*header) +
391 		sizeof(*chksum_ptr);
392 	if (total_size != fw->size)
393 		return ERR_INVALID_SIZE;
394 
395 	/* The checksum comes at the very end. */
396 	chksum_ptr = (void *)fw->data + sizeof(*header) + dmem_size + imem_size;
397 
398 	init->is_big_endian = is_big_endian;
399 	init->dmem_len = dmem_size;
400 	init->imem_len = imem_size;
401 	init->chksum = (is_big_endian)
402 		? be32_to_cpu(*chksum_ptr) : le32_to_cpu(*chksum_ptr);
403 
404 	return 0;
405 }
406 
407 /* Verify checksum by reading back the firmware from co-processor RAM. */
408 static int __verify_fw_checksum(struct init_data *init,
409 				struct private_data *priv,
410 				const struct dpfe_firmware_header *header,
411 				u32 checksum)
412 {
413 	u32 magic, sequence, version, sum;
414 	u32 __iomem *dmem = priv->dmem;
415 	u32 __iomem *imem = priv->imem;
416 	unsigned int i;
417 
418 	if (init->is_big_endian) {
419 		magic = be32_to_cpu(header->magic);
420 		sequence = be32_to_cpu(header->sequence);
421 		version = be32_to_cpu(header->version);
422 	} else {
423 		magic = le32_to_cpu(header->magic);
424 		sequence = le32_to_cpu(header->sequence);
425 		version = le32_to_cpu(header->version);
426 	}
427 
428 	sum = magic + sequence + version + init->dmem_len + init->imem_len;
429 
430 	for (i = 0; i < init->dmem_len / sizeof(u32); i++)
431 		sum += readl_relaxed(dmem + i);
432 
433 	for (i = 0; i < init->imem_len / sizeof(u32); i++)
434 		sum += readl_relaxed(imem + i);
435 
436 	return (sum == checksum) ? 0 : -1;
437 }
438 
439 static int __write_firmware(u32 __iomem *mem, const u32 *fw,
440 			    unsigned int size, bool is_big_endian)
441 {
442 	unsigned int i;
443 
444 	/* Convert size to 32-bit words. */
445 	size /= sizeof(u32);
446 
447 	/* It is recommended to clear the firmware area first. */
448 	for (i = 0; i < size; i++)
449 		writel_relaxed(0, mem + i);
450 
451 	/* Now copy it. */
452 	if (is_big_endian) {
453 		for (i = 0; i < size; i++)
454 			writel_relaxed(be32_to_cpu(fw[i]), mem + i);
455 	} else {
456 		for (i = 0; i < size; i++)
457 			writel_relaxed(le32_to_cpu(fw[i]), mem + i);
458 	}
459 
460 	return 0;
461 }
462 
463 static int brcmstb_dpfe_download_firmware(struct platform_device *pdev,
464 					  struct init_data *init)
465 {
466 	const struct dpfe_firmware_header *header;
467 	unsigned int dmem_size, imem_size;
468 	struct device *dev = &pdev->dev;
469 	bool is_big_endian = false;
470 	struct private_data *priv;
471 	const struct firmware *fw;
472 	const u32 *dmem, *imem;
473 	const void *fw_blob;
474 	int ret;
475 
476 	priv = platform_get_drvdata(pdev);
477 
478 	/*
479 	 * Skip downloading the firmware if the DCPU is already running and
480 	 * responding to commands.
481 	 */
482 	if (is_dcpu_enabled(priv->regs)) {
483 		u32 response[MSG_FIELD_MAX];
484 
485 		ret = __send_command(priv, DPFE_CMD_GET_INFO, response);
486 		if (!ret)
487 			return 0;
488 	}
489 
490 	ret = request_firmware(&fw, FIRMWARE_NAME, dev);
491 	/* request_firmware() prints its own error messages. */
492 	if (ret)
493 		return ret;
494 
495 	ret = __verify_firmware(init, fw);
496 	if (ret)
497 		return -EFAULT;
498 
499 	__disable_dcpu(priv->regs);
500 
501 	is_big_endian = init->is_big_endian;
502 	dmem_size = init->dmem_len;
503 	imem_size = init->imem_len;
504 
505 	/* At the beginning of the firmware blob is a header. */
506 	header = (struct dpfe_firmware_header *)fw->data;
507 	/* Void pointer to the beginning of the actual firmware. */
508 	fw_blob = fw->data + sizeof(*header);
509 	/* IMEM comes right after the header. */
510 	imem = fw_blob;
511 	/* DMEM follows after IMEM. */
512 	dmem = fw_blob + imem_size;
513 
514 	ret = __write_firmware(priv->dmem, dmem, dmem_size, is_big_endian);
515 	if (ret)
516 		return ret;
517 	ret = __write_firmware(priv->imem, imem, imem_size, is_big_endian);
518 	if (ret)
519 		return ret;
520 
521 	ret = __verify_fw_checksum(init, priv, header, init->chksum);
522 	if (ret)
523 		return ret;
524 
525 	__enable_dcpu(priv->regs);
526 
527 	return 0;
528 }
529 
530 static ssize_t generic_show(unsigned int command, u32 response[],
531 			    struct device *dev, char *buf)
532 {
533 	struct private_data *priv;
534 	int ret;
535 
536 	priv = dev_get_drvdata(dev);
537 	if (!priv)
538 		return sprintf(buf, "ERROR: driver private data not set\n");
539 
540 	ret = __send_command(priv, command, response);
541 	if (ret < 0)
542 		return sprintf(buf, "ERROR: %s\n", error_text[-ret]);
543 
544 	return 0;
545 }
546 
547 static ssize_t show_info(struct device *dev, struct device_attribute *devattr,
548 			 char *buf)
549 {
550 	u32 response[MSG_FIELD_MAX];
551 	unsigned int info;
552 	ssize_t ret;
553 
554 	ret = generic_show(DPFE_CMD_GET_INFO, response, dev, buf);
555 	if (ret)
556 		return ret;
557 
558 	info = response[MSG_ARG0];
559 
560 	return sprintf(buf, "%u.%u.%u.%u\n",
561 		       (info >> 24) & 0xff,
562 		       (info >> 16) & 0xff,
563 		       (info >> 8) & 0xff,
564 		       info & 0xff);
565 }
566 
567 static ssize_t show_refresh(struct device *dev,
568 			    struct device_attribute *devattr, char *buf)
569 {
570 	u32 response[MSG_FIELD_MAX];
571 	void __iomem *info;
572 	struct private_data *priv;
573 	u8 refresh, sr_abort, ppre, thermal_offs, tuf;
574 	u32 mr4;
575 	ssize_t ret;
576 
577 	ret = generic_show(DPFE_CMD_GET_REFRESH, response, dev, buf);
578 	if (ret)
579 		return ret;
580 
581 	priv = dev_get_drvdata(dev);
582 
583 	info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
584 	if (!info)
585 		return ret;
586 
587 	mr4 = readl_relaxed(info + DRAM_INFO_MR4) & DRAM_INFO_MR4_MASK;
588 
589 	refresh = (mr4 >> DRAM_MR4_REFRESH) & DRAM_MR4_REFRESH_MASK;
590 	sr_abort = (mr4 >> DRAM_MR4_SR_ABORT) & DRAM_MR4_SR_ABORT_MASK;
591 	ppre = (mr4 >> DRAM_MR4_PPRE) & DRAM_MR4_PPRE_MASK;
592 	thermal_offs = (mr4 >> DRAM_MR4_TH_OFFS) & DRAM_MR4_TH_OFFS_MASK;
593 	tuf = (mr4 >> DRAM_MR4_TUF) & DRAM_MR4_TUF_MASK;
594 
595 	return sprintf(buf, "%#x %#x %#x %#x %#x %#x %#x\n",
596 		       readl_relaxed(info + DRAM_INFO_INTERVAL),
597 		       refresh, sr_abort, ppre, thermal_offs, tuf,
598 		       readl_relaxed(info + DRAM_INFO_ERROR));
599 }
600 
601 static ssize_t store_refresh(struct device *dev, struct device_attribute *attr,
602 			  const char *buf, size_t count)
603 {
604 	u32 response[MSG_FIELD_MAX];
605 	struct private_data *priv;
606 	void __iomem *info;
607 	unsigned long val;
608 	int ret;
609 
610 	if (kstrtoul(buf, 0, &val) < 0)
611 		return -EINVAL;
612 
613 	priv = dev_get_drvdata(dev);
614 
615 	ret = __send_command(priv, DPFE_CMD_GET_REFRESH, response);
616 	if (ret)
617 		return ret;
618 
619 	info = get_msg_ptr(priv, response[MSG_ARG0], NULL, NULL);
620 	if (!info)
621 		return -EIO;
622 
623 	writel_relaxed(val, info + DRAM_INFO_INTERVAL);
624 
625 	return count;
626 }
627 
628 static ssize_t show_vendor(struct device *dev, struct device_attribute *devattr,
629 			 char *buf)
630 {
631 	u32 response[MSG_FIELD_MAX];
632 	struct private_data *priv;
633 	void __iomem *info;
634 	ssize_t ret;
635 
636 	ret = generic_show(DPFE_CMD_GET_VENDOR, response, dev, buf);
637 	if (ret)
638 		return ret;
639 
640 	priv = dev_get_drvdata(dev);
641 
642 	info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
643 	if (!info)
644 		return ret;
645 
646 	return sprintf(buf, "%#x %#x %#x %#x %#x\n",
647 		       readl_relaxed(info + DRAM_VENDOR_MR5) & DRAM_VENDOR_MASK,
648 		       readl_relaxed(info + DRAM_VENDOR_MR6) & DRAM_VENDOR_MASK,
649 		       readl_relaxed(info + DRAM_VENDOR_MR7) & DRAM_VENDOR_MASK,
650 		       readl_relaxed(info + DRAM_VENDOR_MR8) & DRAM_VENDOR_MASK,
651 		       readl_relaxed(info + DRAM_VENDOR_ERROR) &
652 				     DRAM_VENDOR_MASK);
653 }
654 
655 static int brcmstb_dpfe_resume(struct platform_device *pdev)
656 {
657 	struct init_data init;
658 
659 	return brcmstb_dpfe_download_firmware(pdev, &init);
660 }
661 
662 static DEVICE_ATTR(dpfe_info, 0444, show_info, NULL);
663 static DEVICE_ATTR(dpfe_refresh, 0644, show_refresh, store_refresh);
664 static DEVICE_ATTR(dpfe_vendor, 0444, show_vendor, NULL);
665 static struct attribute *dpfe_attrs[] = {
666 	&dev_attr_dpfe_info.attr,
667 	&dev_attr_dpfe_refresh.attr,
668 	&dev_attr_dpfe_vendor.attr,
669 	NULL
670 };
671 ATTRIBUTE_GROUPS(dpfe);
672 
673 static int brcmstb_dpfe_probe(struct platform_device *pdev)
674 {
675 	struct device *dev = &pdev->dev;
676 	struct private_data *priv;
677 	struct device *dpfe_dev;
678 	struct init_data init;
679 	struct resource *res;
680 	u32 index;
681 	int ret;
682 
683 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
684 	if (!priv)
685 		return -ENOMEM;
686 
687 	mutex_init(&priv->lock);
688 	platform_set_drvdata(pdev, priv);
689 
690 	/* Cell index is optional; default to 0 if not present. */
691 	ret = of_property_read_u32(dev->of_node, "cell-index", &index);
692 	if (ret)
693 		index = 0;
694 
695 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-cpu");
696 	priv->regs = devm_ioremap_resource(dev, res);
697 	if (IS_ERR(priv->regs)) {
698 		dev_err(dev, "couldn't map DCPU registers\n");
699 		return -ENODEV;
700 	}
701 
702 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-dmem");
703 	priv->dmem = devm_ioremap_resource(dev, res);
704 	if (IS_ERR(priv->dmem)) {
705 		dev_err(dev, "Couldn't map DCPU data memory\n");
706 		return -ENOENT;
707 	}
708 
709 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-imem");
710 	priv->imem = devm_ioremap_resource(dev, res);
711 	if (IS_ERR(priv->imem)) {
712 		dev_err(dev, "Couldn't map DCPU instruction memory\n");
713 		return -ENOENT;
714 	}
715 
716 	ret = brcmstb_dpfe_download_firmware(pdev, &init);
717 	if (ret)
718 		goto err;
719 
720 	dpfe_dev = devm_kzalloc(dev, sizeof(*dpfe_dev), GFP_KERNEL);
721 	if (!dpfe_dev) {
722 		ret = -ENOMEM;
723 		goto err;
724 	}
725 
726 	priv->dev = dpfe_dev;
727 	priv->index = index;
728 
729 	dpfe_dev->parent = dev;
730 	dpfe_dev->groups = dpfe_groups;
731 	dpfe_dev->of_node = dev->of_node;
732 	dev_set_drvdata(dpfe_dev, priv);
733 	dev_set_name(dpfe_dev, "dpfe%u", index);
734 
735 	ret = device_register(dpfe_dev);
736 	if (ret)
737 		goto err;
738 
739 	dev_info(dev, "registered.\n");
740 
741 	return 0;
742 
743 err:
744 	dev_err(dev, "failed to initialize -- error %d\n", ret);
745 
746 	return ret;
747 }
748 
749 static const struct of_device_id brcmstb_dpfe_of_match[] = {
750 	{ .compatible = "brcm,dpfe-cpu", },
751 	{}
752 };
753 MODULE_DEVICE_TABLE(of, brcmstb_dpfe_of_match);
754 
755 static struct platform_driver brcmstb_dpfe_driver = {
756 	.driver	= {
757 		.name = DRVNAME,
758 		.of_match_table = brcmstb_dpfe_of_match,
759 	},
760 	.probe = brcmstb_dpfe_probe,
761 	.resume = brcmstb_dpfe_resume,
762 };
763 
764 module_platform_driver(brcmstb_dpfe_driver);
765 
766 MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
767 MODULE_DESCRIPTION("BRCMSTB DDR PHY Front End Driver");
768 MODULE_LICENSE("GPL");
769