xref: /openbmc/linux/drivers/memory/brcmstb_dpfe.c (revision 4a3fad70)
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 /* Message RAM */
49 #define DCPU_MSG_RAM(x)		(0x100 + (x) * sizeof(u32))
50 
51 /* DRAM Info Offsets & Masks */
52 #define DRAM_INFO_INTERVAL	0x0
53 #define DRAM_INFO_MR4		0x4
54 #define DRAM_INFO_ERROR		0x8
55 #define DRAM_INFO_MR4_MASK	0xff
56 
57 /* DRAM MR4 Offsets & Masks */
58 #define DRAM_MR4_REFRESH	0x0	/* Refresh rate */
59 #define DRAM_MR4_SR_ABORT	0x3	/* Self Refresh Abort */
60 #define DRAM_MR4_PPRE		0x4	/* Post-package repair entry/exit */
61 #define DRAM_MR4_TH_OFFS	0x5	/* Thermal Offset; vendor specific */
62 #define DRAM_MR4_TUF		0x7	/* Temperature Update Flag */
63 
64 #define DRAM_MR4_REFRESH_MASK	0x7
65 #define DRAM_MR4_SR_ABORT_MASK	0x1
66 #define DRAM_MR4_PPRE_MASK	0x1
67 #define DRAM_MR4_TH_OFFS_MASK	0x3
68 #define DRAM_MR4_TUF_MASK	0x1
69 
70 /* DRAM Vendor Offsets & Masks */
71 #define DRAM_VENDOR_MR5		0x0
72 #define DRAM_VENDOR_MR6		0x4
73 #define DRAM_VENDOR_MR7		0x8
74 #define DRAM_VENDOR_MR8		0xc
75 #define DRAM_VENDOR_ERROR	0x10
76 #define DRAM_VENDOR_MASK	0xff
77 
78 /* Reset register bits & masks */
79 #define DCPU_RESET_SHIFT	0x0
80 #define DCPU_RESET_MASK		0x1
81 #define DCPU_CLK_DISABLE_SHIFT	0x2
82 
83 /* DCPU return codes */
84 #define DCPU_RET_ERROR_BIT	BIT(31)
85 #define DCPU_RET_SUCCESS	0x1
86 #define DCPU_RET_ERR_HEADER	(DCPU_RET_ERROR_BIT | BIT(0))
87 #define DCPU_RET_ERR_INVAL	(DCPU_RET_ERROR_BIT | BIT(1))
88 #define DCPU_RET_ERR_CHKSUM	(DCPU_RET_ERROR_BIT | BIT(2))
89 #define DCPU_RET_ERR_COMMAND	(DCPU_RET_ERROR_BIT | BIT(3))
90 /* This error code is not firmware defined and only used in the driver. */
91 #define DCPU_RET_ERR_TIMEDOUT	(DCPU_RET_ERROR_BIT | BIT(4))
92 
93 /* Firmware magic */
94 #define DPFE_BE_MAGIC		0xfe1010fe
95 #define DPFE_LE_MAGIC		0xfe0101fe
96 
97 /* Error codes */
98 #define ERR_INVALID_MAGIC	-1
99 #define ERR_INVALID_SIZE	-2
100 #define ERR_INVALID_CHKSUM	-3
101 
102 /* Message types */
103 #define DPFE_MSG_TYPE_COMMAND	1
104 #define DPFE_MSG_TYPE_RESPONSE	2
105 
106 #define DELAY_LOOP_MAX		200000
107 
108 enum dpfe_msg_fields {
109 	MSG_HEADER,
110 	MSG_COMMAND,
111 	MSG_ARG_COUNT,
112 	MSG_ARG0,
113 	MSG_CHKSUM,
114 	MSG_FIELD_MAX /* Last entry */
115 };
116 
117 enum dpfe_commands {
118 	DPFE_CMD_GET_INFO,
119 	DPFE_CMD_GET_REFRESH,
120 	DPFE_CMD_GET_VENDOR,
121 	DPFE_CMD_MAX /* Last entry */
122 };
123 
124 struct dpfe_msg {
125 	u32 header;
126 	u32 command;
127 	u32 arg_count;
128 	u32 arg0;
129 	u32 chksum; /* This is the sum of all other entries. */
130 };
131 
132 /*
133  * Format of the binary firmware file:
134  *
135  *   entry
136  *      0    header
137  *              value:  0xfe0101fe  <== little endian
138  *                      0xfe1010fe  <== big endian
139  *      1    sequence:
140  *              [31:16] total segments on this build
141  *              [15:0]  this segment sequence.
142  *      2    FW version
143  *      3    IMEM byte size
144  *      4    DMEM byte size
145  *           IMEM
146  *           DMEM
147  *      last checksum ==> sum of everything
148  */
149 struct dpfe_firmware_header {
150 	u32 magic;
151 	u32 sequence;
152 	u32 version;
153 	u32 imem_size;
154 	u32 dmem_size;
155 };
156 
157 /* Things we only need during initialization. */
158 struct init_data {
159 	unsigned int dmem_len;
160 	unsigned int imem_len;
161 	unsigned int chksum;
162 	bool is_big_endian;
163 };
164 
165 /* Things we need for as long as we are active. */
166 struct private_data {
167 	void __iomem *regs;
168 	void __iomem *dmem;
169 	void __iomem *imem;
170 	struct device *dev;
171 	unsigned int index;
172 	struct mutex lock;
173 };
174 
175 static const char *error_text[] = {
176 	"Success", "Header code incorrect", "Unknown command or argument",
177 	"Incorrect checksum", "Malformed command", "Timed out",
178 };
179 
180 /* List of supported firmware commands */
181 static const u32 dpfe_commands[DPFE_CMD_MAX][MSG_FIELD_MAX] = {
182 	[DPFE_CMD_GET_INFO] = {
183 		[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
184 		[MSG_COMMAND] = 1,
185 		[MSG_ARG_COUNT] = 1,
186 		[MSG_ARG0] = 1,
187 		[MSG_CHKSUM] = 4,
188 	},
189 	[DPFE_CMD_GET_REFRESH] = {
190 		[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
191 		[MSG_COMMAND] = 2,
192 		[MSG_ARG_COUNT] = 1,
193 		[MSG_ARG0] = 1,
194 		[MSG_CHKSUM] = 5,
195 	},
196 	[DPFE_CMD_GET_VENDOR] = {
197 		[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
198 		[MSG_COMMAND] = 2,
199 		[MSG_ARG_COUNT] = 1,
200 		[MSG_ARG0] = 2,
201 		[MSG_CHKSUM] = 6,
202 	},
203 };
204 
205 static bool is_dcpu_enabled(void __iomem *regs)
206 {
207 	u32 val;
208 
209 	val = readl_relaxed(regs + REG_DCPU_RESET);
210 
211 	return !(val & DCPU_RESET_MASK);
212 }
213 
214 static void __disable_dcpu(void __iomem *regs)
215 {
216 	u32 val;
217 
218 	if (!is_dcpu_enabled(regs))
219 		return;
220 
221 	/* Put DCPU in reset if it's running. */
222 	val = readl_relaxed(regs + REG_DCPU_RESET);
223 	val |= (1 << DCPU_RESET_SHIFT);
224 	writel_relaxed(val, regs + REG_DCPU_RESET);
225 }
226 
227 static void __enable_dcpu(void __iomem *regs)
228 {
229 	u32 val;
230 
231 	/* Clear mailbox registers. */
232 	writel_relaxed(0, regs + REG_TO_DCPU_MBOX);
233 	writel_relaxed(0, regs + REG_TO_HOST_MBOX);
234 
235 	/* Disable DCPU clock gating */
236 	val = readl_relaxed(regs + REG_DCPU_RESET);
237 	val &= ~(1 << DCPU_CLK_DISABLE_SHIFT);
238 	writel_relaxed(val, regs + REG_DCPU_RESET);
239 
240 	/* Take DCPU out of reset */
241 	val = readl_relaxed(regs + REG_DCPU_RESET);
242 	val &= ~(1 << DCPU_RESET_SHIFT);
243 	writel_relaxed(val, regs + REG_DCPU_RESET);
244 }
245 
246 static unsigned int get_msg_chksum(const u32 msg[])
247 {
248 	unsigned int sum = 0;
249 	unsigned int i;
250 
251 	/* Don't include the last field in the checksum. */
252 	for (i = 0; i < MSG_FIELD_MAX - 1; i++)
253 		sum += msg[i];
254 
255 	return sum;
256 }
257 
258 static int __send_command(struct private_data *priv, unsigned int cmd,
259 			  u32 result[])
260 {
261 	const u32 *msg = dpfe_commands[cmd];
262 	void __iomem *regs = priv->regs;
263 	unsigned int i, chksum;
264 	int ret = 0;
265 	u32 resp;
266 
267 	if (cmd >= DPFE_CMD_MAX)
268 		return -1;
269 
270 	mutex_lock(&priv->lock);
271 
272 	/* Write command and arguments to message area */
273 	for (i = 0; i < MSG_FIELD_MAX; i++)
274 		writel_relaxed(msg[i], regs + DCPU_MSG_RAM(i));
275 
276 	/* Tell DCPU there is a command waiting */
277 	writel_relaxed(1, regs + REG_TO_DCPU_MBOX);
278 
279 	/* Wait for DCPU to process the command */
280 	for (i = 0; i < DELAY_LOOP_MAX; i++) {
281 		/* Read response code */
282 		resp = readl_relaxed(regs + REG_TO_HOST_MBOX);
283 		if (resp > 0)
284 			break;
285 		udelay(5);
286 	}
287 
288 	if (i == DELAY_LOOP_MAX) {
289 		resp = (DCPU_RET_ERR_TIMEDOUT & ~DCPU_RET_ERROR_BIT);
290 		ret = -ffs(resp);
291 	} else {
292 		/* Read response data */
293 		for (i = 0; i < MSG_FIELD_MAX; i++)
294 			result[i] = readl_relaxed(regs + DCPU_MSG_RAM(i));
295 	}
296 
297 	/* Tell DCPU we are done */
298 	writel_relaxed(0, regs + REG_TO_HOST_MBOX);
299 
300 	mutex_unlock(&priv->lock);
301 
302 	if (ret)
303 		return ret;
304 
305 	/* Verify response */
306 	chksum = get_msg_chksum(result);
307 	if (chksum != result[MSG_CHKSUM])
308 		resp = DCPU_RET_ERR_CHKSUM;
309 
310 	if (resp != DCPU_RET_SUCCESS) {
311 		resp &= ~DCPU_RET_ERROR_BIT;
312 		ret = -ffs(resp);
313 	}
314 
315 	return ret;
316 }
317 
318 /* Ensure that the firmware file loaded meets all the requirements. */
319 static int __verify_firmware(struct init_data *init,
320 			     const struct firmware *fw)
321 {
322 	const struct dpfe_firmware_header *header = (void *)fw->data;
323 	unsigned int dmem_size, imem_size, total_size;
324 	bool is_big_endian = false;
325 	const u32 *chksum_ptr;
326 
327 	if (header->magic == DPFE_BE_MAGIC)
328 		is_big_endian = true;
329 	else if (header->magic != DPFE_LE_MAGIC)
330 		return ERR_INVALID_MAGIC;
331 
332 	if (is_big_endian) {
333 		dmem_size = be32_to_cpu(header->dmem_size);
334 		imem_size = be32_to_cpu(header->imem_size);
335 	} else {
336 		dmem_size = le32_to_cpu(header->dmem_size);
337 		imem_size = le32_to_cpu(header->imem_size);
338 	}
339 
340 	/* Data and instruction sections are 32 bit words. */
341 	if ((dmem_size % sizeof(u32)) != 0 || (imem_size % sizeof(u32)) != 0)
342 		return ERR_INVALID_SIZE;
343 
344 	/*
345 	 * The header + the data section + the instruction section + the
346 	 * checksum must be equal to the total firmware size.
347 	 */
348 	total_size = dmem_size + imem_size + sizeof(*header) +
349 		sizeof(*chksum_ptr);
350 	if (total_size != fw->size)
351 		return ERR_INVALID_SIZE;
352 
353 	/* The checksum comes at the very end. */
354 	chksum_ptr = (void *)fw->data + sizeof(*header) + dmem_size + imem_size;
355 
356 	init->is_big_endian = is_big_endian;
357 	init->dmem_len = dmem_size;
358 	init->imem_len = imem_size;
359 	init->chksum = (is_big_endian)
360 		? be32_to_cpu(*chksum_ptr) : le32_to_cpu(*chksum_ptr);
361 
362 	return 0;
363 }
364 
365 /* Verify checksum by reading back the firmware from co-processor RAM. */
366 static int __verify_fw_checksum(struct init_data *init,
367 				struct private_data *priv,
368 				const struct dpfe_firmware_header *header,
369 				u32 checksum)
370 {
371 	u32 magic, sequence, version, sum;
372 	u32 __iomem *dmem = priv->dmem;
373 	u32 __iomem *imem = priv->imem;
374 	unsigned int i;
375 
376 	if (init->is_big_endian) {
377 		magic = be32_to_cpu(header->magic);
378 		sequence = be32_to_cpu(header->sequence);
379 		version = be32_to_cpu(header->version);
380 	} else {
381 		magic = le32_to_cpu(header->magic);
382 		sequence = le32_to_cpu(header->sequence);
383 		version = le32_to_cpu(header->version);
384 	}
385 
386 	sum = magic + sequence + version + init->dmem_len + init->imem_len;
387 
388 	for (i = 0; i < init->dmem_len / sizeof(u32); i++)
389 		sum += readl_relaxed(dmem + i);
390 
391 	for (i = 0; i < init->imem_len / sizeof(u32); i++)
392 		sum += readl_relaxed(imem + i);
393 
394 	return (sum == checksum) ? 0 : -1;
395 }
396 
397 static int __write_firmware(u32 __iomem *mem, const u32 *fw,
398 			    unsigned int size, bool is_big_endian)
399 {
400 	unsigned int i;
401 
402 	/* Convert size to 32-bit words. */
403 	size /= sizeof(u32);
404 
405 	/* It is recommended to clear the firmware area first. */
406 	for (i = 0; i < size; i++)
407 		writel_relaxed(0, mem + i);
408 
409 	/* Now copy it. */
410 	if (is_big_endian) {
411 		for (i = 0; i < size; i++)
412 			writel_relaxed(be32_to_cpu(fw[i]), mem + i);
413 	} else {
414 		for (i = 0; i < size; i++)
415 			writel_relaxed(le32_to_cpu(fw[i]), mem + i);
416 	}
417 
418 	return 0;
419 }
420 
421 static int brcmstb_dpfe_download_firmware(struct platform_device *pdev,
422 					  struct init_data *init)
423 {
424 	const struct dpfe_firmware_header *header;
425 	unsigned int dmem_size, imem_size;
426 	struct device *dev = &pdev->dev;
427 	bool is_big_endian = false;
428 	struct private_data *priv;
429 	const struct firmware *fw;
430 	const u32 *dmem, *imem;
431 	const void *fw_blob;
432 	int ret;
433 
434 	priv = platform_get_drvdata(pdev);
435 
436 	/*
437 	 * Skip downloading the firmware if the DCPU is already running and
438 	 * responding to commands.
439 	 */
440 	if (is_dcpu_enabled(priv->regs)) {
441 		u32 response[MSG_FIELD_MAX];
442 
443 		ret = __send_command(priv, DPFE_CMD_GET_INFO, response);
444 		if (!ret)
445 			return 0;
446 	}
447 
448 	ret = request_firmware(&fw, FIRMWARE_NAME, dev);
449 	/* request_firmware() prints its own error messages. */
450 	if (ret)
451 		return ret;
452 
453 	ret = __verify_firmware(init, fw);
454 	if (ret)
455 		return -EFAULT;
456 
457 	__disable_dcpu(priv->regs);
458 
459 	is_big_endian = init->is_big_endian;
460 	dmem_size = init->dmem_len;
461 	imem_size = init->imem_len;
462 
463 	/* At the beginning of the firmware blob is a header. */
464 	header = (struct dpfe_firmware_header *)fw->data;
465 	/* Void pointer to the beginning of the actual firmware. */
466 	fw_blob = fw->data + sizeof(*header);
467 	/* IMEM comes right after the header. */
468 	imem = fw_blob;
469 	/* DMEM follows after IMEM. */
470 	dmem = fw_blob + imem_size;
471 
472 	ret = __write_firmware(priv->dmem, dmem, dmem_size, is_big_endian);
473 	if (ret)
474 		return ret;
475 	ret = __write_firmware(priv->imem, imem, imem_size, is_big_endian);
476 	if (ret)
477 		return ret;
478 
479 	ret = __verify_fw_checksum(init, priv, header, init->chksum);
480 	if (ret)
481 		return ret;
482 
483 	__enable_dcpu(priv->regs);
484 
485 	return 0;
486 }
487 
488 static ssize_t generic_show(unsigned int command, u32 response[],
489 			    struct device *dev, char *buf)
490 {
491 	struct private_data *priv;
492 	int ret;
493 
494 	priv = dev_get_drvdata(dev);
495 	if (!priv)
496 		return sprintf(buf, "ERROR: driver private data not set\n");
497 
498 	ret = __send_command(priv, command, response);
499 	if (ret < 0)
500 		return sprintf(buf, "ERROR: %s\n", error_text[-ret]);
501 
502 	return 0;
503 }
504 
505 static ssize_t show_info(struct device *dev, struct device_attribute *devattr,
506 			 char *buf)
507 {
508 	u32 response[MSG_FIELD_MAX];
509 	unsigned int info;
510 	int ret;
511 
512 	ret = generic_show(DPFE_CMD_GET_INFO, response, dev, buf);
513 	if (ret)
514 		return ret;
515 
516 	info = response[MSG_ARG0];
517 
518 	return sprintf(buf, "%u.%u.%u.%u\n",
519 		       (info >> 24) & 0xff,
520 		       (info >> 16) & 0xff,
521 		       (info >> 8) & 0xff,
522 		       info & 0xff);
523 }
524 
525 static ssize_t show_refresh(struct device *dev,
526 			    struct device_attribute *devattr, char *buf)
527 {
528 	u32 response[MSG_FIELD_MAX];
529 	void __iomem *info;
530 	struct private_data *priv;
531 	unsigned int offset;
532 	u8 refresh, sr_abort, ppre, thermal_offs, tuf;
533 	u32 mr4;
534 	int ret;
535 
536 	ret = generic_show(DPFE_CMD_GET_REFRESH, response, dev, buf);
537 	if (ret)
538 		return ret;
539 
540 	priv = dev_get_drvdata(dev);
541 	offset = response[MSG_ARG0];
542 	info = priv->dmem + offset;
543 
544 	mr4 = readl_relaxed(info + DRAM_INFO_MR4) & DRAM_INFO_MR4_MASK;
545 
546 	refresh = (mr4 >> DRAM_MR4_REFRESH) & DRAM_MR4_REFRESH_MASK;
547 	sr_abort = (mr4 >> DRAM_MR4_SR_ABORT) & DRAM_MR4_SR_ABORT_MASK;
548 	ppre = (mr4 >> DRAM_MR4_PPRE) & DRAM_MR4_PPRE_MASK;
549 	thermal_offs = (mr4 >> DRAM_MR4_TH_OFFS) & DRAM_MR4_TH_OFFS_MASK;
550 	tuf = (mr4 >> DRAM_MR4_TUF) & DRAM_MR4_TUF_MASK;
551 
552 	return sprintf(buf, "%#x %#x %#x %#x %#x %#x %#x\n",
553 		       readl_relaxed(info + DRAM_INFO_INTERVAL),
554 		       refresh, sr_abort, ppre, thermal_offs, tuf,
555 		       readl_relaxed(info + DRAM_INFO_ERROR));
556 }
557 
558 static ssize_t store_refresh(struct device *dev, struct device_attribute *attr,
559 			  const char *buf, size_t count)
560 {
561 	u32 response[MSG_FIELD_MAX];
562 	struct private_data *priv;
563 	void __iomem *info;
564 	unsigned int offset;
565 	unsigned long val;
566 	int ret;
567 
568 	if (kstrtoul(buf, 0, &val) < 0)
569 		return -EINVAL;
570 
571 	priv = dev_get_drvdata(dev);
572 
573 	ret = __send_command(priv, DPFE_CMD_GET_REFRESH, response);
574 	if (ret)
575 		return ret;
576 
577 	offset = response[MSG_ARG0];
578 	info = priv->dmem + offset;
579 	writel_relaxed(val, info + DRAM_INFO_INTERVAL);
580 
581 	return count;
582 }
583 
584 static ssize_t show_vendor(struct device *dev, struct device_attribute *devattr,
585 			 char *buf)
586 {
587 	u32 response[MSG_FIELD_MAX];
588 	struct private_data *priv;
589 	void __iomem *info;
590 	unsigned int offset;
591 	int ret;
592 
593 	ret = generic_show(DPFE_CMD_GET_VENDOR, response, dev, buf);
594 	if (ret)
595 		return ret;
596 
597 	offset = response[MSG_ARG0];
598 	priv = dev_get_drvdata(dev);
599 	info = priv->dmem + offset;
600 
601 	return sprintf(buf, "%#x %#x %#x %#x %#x\n",
602 		       readl_relaxed(info + DRAM_VENDOR_MR5) & DRAM_VENDOR_MASK,
603 		       readl_relaxed(info + DRAM_VENDOR_MR6) & DRAM_VENDOR_MASK,
604 		       readl_relaxed(info + DRAM_VENDOR_MR7) & DRAM_VENDOR_MASK,
605 		       readl_relaxed(info + DRAM_VENDOR_MR8) & DRAM_VENDOR_MASK,
606 		       readl_relaxed(info + DRAM_VENDOR_ERROR));
607 }
608 
609 static int brcmstb_dpfe_resume(struct platform_device *pdev)
610 {
611 	struct init_data init;
612 
613 	return brcmstb_dpfe_download_firmware(pdev, &init);
614 }
615 
616 static DEVICE_ATTR(dpfe_info, 0444, show_info, NULL);
617 static DEVICE_ATTR(dpfe_refresh, 0644, show_refresh, store_refresh);
618 static DEVICE_ATTR(dpfe_vendor, 0444, show_vendor, NULL);
619 static struct attribute *dpfe_attrs[] = {
620 	&dev_attr_dpfe_info.attr,
621 	&dev_attr_dpfe_refresh.attr,
622 	&dev_attr_dpfe_vendor.attr,
623 	NULL
624 };
625 ATTRIBUTE_GROUPS(dpfe);
626 
627 static int brcmstb_dpfe_probe(struct platform_device *pdev)
628 {
629 	struct device *dev = &pdev->dev;
630 	struct private_data *priv;
631 	struct device *dpfe_dev;
632 	struct init_data init;
633 	struct resource *res;
634 	u32 index;
635 	int ret;
636 
637 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
638 	if (!priv)
639 		return -ENOMEM;
640 
641 	mutex_init(&priv->lock);
642 	platform_set_drvdata(pdev, priv);
643 
644 	/* Cell index is optional; default to 0 if not present. */
645 	ret = of_property_read_u32(dev->of_node, "cell-index", &index);
646 	if (ret)
647 		index = 0;
648 
649 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-cpu");
650 	priv->regs = devm_ioremap_resource(dev, res);
651 	if (IS_ERR(priv->regs)) {
652 		dev_err(dev, "couldn't map DCPU registers\n");
653 		return -ENODEV;
654 	}
655 
656 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-dmem");
657 	priv->dmem = devm_ioremap_resource(dev, res);
658 	if (IS_ERR(priv->dmem)) {
659 		dev_err(dev, "Couldn't map DCPU data memory\n");
660 		return -ENOENT;
661 	}
662 
663 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-imem");
664 	priv->imem = devm_ioremap_resource(dev, res);
665 	if (IS_ERR(priv->imem)) {
666 		dev_err(dev, "Couldn't map DCPU instruction memory\n");
667 		return -ENOENT;
668 	}
669 
670 	ret = brcmstb_dpfe_download_firmware(pdev, &init);
671 	if (ret)
672 		goto err;
673 
674 	dpfe_dev = devm_kzalloc(dev, sizeof(*dpfe_dev), GFP_KERNEL);
675 	if (!dpfe_dev) {
676 		ret = -ENOMEM;
677 		goto err;
678 	}
679 
680 	priv->dev = dpfe_dev;
681 	priv->index = index;
682 
683 	dpfe_dev->parent = dev;
684 	dpfe_dev->groups = dpfe_groups;
685 	dpfe_dev->of_node = dev->of_node;
686 	dev_set_drvdata(dpfe_dev, priv);
687 	dev_set_name(dpfe_dev, "dpfe%u", index);
688 
689 	ret = device_register(dpfe_dev);
690 	if (ret)
691 		goto err;
692 
693 	dev_info(dev, "registered.\n");
694 
695 	return 0;
696 
697 err:
698 	dev_err(dev, "failed to initialize -- error %d\n", ret);
699 
700 	return ret;
701 }
702 
703 static const struct of_device_id brcmstb_dpfe_of_match[] = {
704 	{ .compatible = "brcm,dpfe-cpu", },
705 	{}
706 };
707 MODULE_DEVICE_TABLE(of, brcmstb_dpfe_of_match);
708 
709 static struct platform_driver brcmstb_dpfe_driver = {
710 	.driver	= {
711 		.name = DRVNAME,
712 		.of_match_table = brcmstb_dpfe_of_match,
713 	},
714 	.probe = brcmstb_dpfe_probe,
715 	.resume = brcmstb_dpfe_resume,
716 };
717 
718 module_platform_driver(brcmstb_dpfe_driver);
719 
720 MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
721 MODULE_DESCRIPTION("BRCMSTB DDR PHY Front End Driver");
722 MODULE_LICENSE("GPL");
723