xref: /openbmc/linux/drivers/memory/brcmstb_dpfe.c (revision 6c33a6f4)
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 firwmare 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 static const char *error_text[] = {
192 	"Success", "Header code incorrect", "Unknown command or argument",
193 	"Incorrect checksum", "Malformed command", "Timed out",
194 };
195 
196 /*
197  * Forward declaration of our sysfs attribute functions, so we can declare the
198  * attribute data structures early.
199  */
200 static ssize_t show_info(struct device *, struct device_attribute *, char *);
201 static ssize_t show_refresh(struct device *, struct device_attribute *, char *);
202 static ssize_t store_refresh(struct device *, struct device_attribute *,
203 			  const char *, size_t);
204 static ssize_t show_vendor(struct device *, struct device_attribute *, char *);
205 static ssize_t show_dram(struct device *, struct device_attribute *, char *);
206 
207 /*
208  * Declare our attributes early, so they can be referenced in the API data
209  * structure. We need to do this, because the attributes depend on the API
210  * version.
211  */
212 static DEVICE_ATTR(dpfe_info, 0444, show_info, NULL);
213 static DEVICE_ATTR(dpfe_refresh, 0644, show_refresh, store_refresh);
214 static DEVICE_ATTR(dpfe_vendor, 0444, show_vendor, NULL);
215 static DEVICE_ATTR(dpfe_dram, 0444, show_dram, NULL);
216 
217 /* API v2 sysfs attributes */
218 static struct attribute *dpfe_v2_attrs[] = {
219 	&dev_attr_dpfe_info.attr,
220 	&dev_attr_dpfe_refresh.attr,
221 	&dev_attr_dpfe_vendor.attr,
222 	NULL
223 };
224 ATTRIBUTE_GROUPS(dpfe_v2);
225 
226 /* API v3 sysfs attributes */
227 static struct attribute *dpfe_v3_attrs[] = {
228 	&dev_attr_dpfe_info.attr,
229 	&dev_attr_dpfe_dram.attr,
230 	NULL
231 };
232 ATTRIBUTE_GROUPS(dpfe_v3);
233 
234 /*
235  * Old API v2 firmware commands, as defined in the rev 0.61 specification, we
236  * use a version set to 1 to denote that it is not compatible with the new API
237  * v2 and onwards.
238  */
239 static const struct dpfe_api dpfe_api_old_v2 = {
240 	.version = 1,
241 	.fw_name = "dpfe.bin",
242 	.sysfs_attrs = dpfe_v2_groups,
243 	.command = {
244 		[DPFE_CMD_GET_INFO] = {
245 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
246 			[MSG_COMMAND] = 1,
247 			[MSG_ARG_COUNT] = 1,
248 			[MSG_ARG0] = 1,
249 		},
250 		[DPFE_CMD_GET_REFRESH] = {
251 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
252 			[MSG_COMMAND] = 2,
253 			[MSG_ARG_COUNT] = 1,
254 			[MSG_ARG0] = 1,
255 		},
256 		[DPFE_CMD_GET_VENDOR] = {
257 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
258 			[MSG_COMMAND] = 2,
259 			[MSG_ARG_COUNT] = 1,
260 			[MSG_ARG0] = 2,
261 		},
262 	}
263 };
264 
265 /*
266  * API v2 firmware commands, as defined in the rev 0.8 specification, named new
267  * v2 here
268  */
269 static const struct dpfe_api dpfe_api_new_v2 = {
270 	.version = 2,
271 	.fw_name = NULL, /* We expect the firmware to have been downloaded! */
272 	.sysfs_attrs = dpfe_v2_groups,
273 	.command = {
274 		[DPFE_CMD_GET_INFO] = {
275 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
276 			[MSG_COMMAND] = 0x101,
277 		},
278 		[DPFE_CMD_GET_REFRESH] = {
279 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
280 			[MSG_COMMAND] = 0x201,
281 		},
282 		[DPFE_CMD_GET_VENDOR] = {
283 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
284 			[MSG_COMMAND] = 0x202,
285 		},
286 	}
287 };
288 
289 /* API v3 firmware commands */
290 static const struct dpfe_api dpfe_api_v3 = {
291 	.version = 3,
292 	.fw_name = NULL, /* We expect the firmware to have been downloaded! */
293 	.sysfs_attrs = dpfe_v3_groups,
294 	.command = {
295 		[DPFE_CMD_GET_INFO] = {
296 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
297 			[MSG_COMMAND] = 0x0101,
298 			[MSG_ARG_COUNT] = 1,
299 			[MSG_ARG0] = 1,
300 		},
301 		[DPFE_CMD_GET_REFRESH] = {
302 			[MSG_HEADER] = DPFE_MSG_TYPE_COMMAND,
303 			[MSG_COMMAND] = 0x0202,
304 			[MSG_ARG_COUNT] = 0,
305 		},
306 		/* There's no GET_VENDOR command in API v3. */
307 	},
308 };
309 
310 static bool is_dcpu_enabled(struct brcmstb_dpfe_priv *priv)
311 {
312 	u32 val;
313 
314 	mutex_lock(&priv->lock);
315 	val = readl_relaxed(priv->regs + REG_DCPU_RESET);
316 	mutex_unlock(&priv->lock);
317 
318 	return !(val & DCPU_RESET_MASK);
319 }
320 
321 static void __disable_dcpu(struct brcmstb_dpfe_priv *priv)
322 {
323 	u32 val;
324 
325 	if (!is_dcpu_enabled(priv))
326 		return;
327 
328 	mutex_lock(&priv->lock);
329 
330 	/* Put DCPU in reset if it's running. */
331 	val = readl_relaxed(priv->regs + REG_DCPU_RESET);
332 	val |= (1 << DCPU_RESET_SHIFT);
333 	writel_relaxed(val, priv->regs + REG_DCPU_RESET);
334 
335 	mutex_unlock(&priv->lock);
336 }
337 
338 static void __enable_dcpu(struct brcmstb_dpfe_priv *priv)
339 {
340 	void __iomem *regs = priv->regs;
341 	u32 val;
342 
343 	mutex_lock(&priv->lock);
344 
345 	/* Clear mailbox registers. */
346 	writel_relaxed(0, regs + REG_TO_DCPU_MBOX);
347 	writel_relaxed(0, regs + REG_TO_HOST_MBOX);
348 
349 	/* Disable DCPU clock gating */
350 	val = readl_relaxed(regs + REG_DCPU_RESET);
351 	val &= ~(1 << DCPU_CLK_DISABLE_SHIFT);
352 	writel_relaxed(val, regs + REG_DCPU_RESET);
353 
354 	/* Take DCPU out of reset */
355 	val = readl_relaxed(regs + REG_DCPU_RESET);
356 	val &= ~(1 << DCPU_RESET_SHIFT);
357 	writel_relaxed(val, regs + REG_DCPU_RESET);
358 
359 	mutex_unlock(&priv->lock);
360 }
361 
362 static unsigned int get_msg_chksum(const u32 msg[], unsigned int max)
363 {
364 	unsigned int sum = 0;
365 	unsigned int i;
366 
367 	/* Don't include the last field in the checksum. */
368 	for (i = 0; i < max; i++)
369 		sum += msg[i];
370 
371 	return sum;
372 }
373 
374 static void __iomem *get_msg_ptr(struct brcmstb_dpfe_priv *priv, u32 response,
375 				 char *buf, ssize_t *size)
376 {
377 	unsigned int msg_type;
378 	unsigned int offset;
379 	void __iomem *ptr = NULL;
380 
381 	/* There is no need to use this function for API v3 or later. */
382 	if (unlikely(priv->dpfe_api->version >= 3)) {
383 		return NULL;
384 	}
385 
386 	msg_type = (response >> DRAM_MSG_TYPE_OFFSET) & DRAM_MSG_TYPE_MASK;
387 	offset = (response >> DRAM_MSG_ADDR_OFFSET) & DRAM_MSG_ADDR_MASK;
388 
389 	/*
390 	 * msg_type == 1: the offset is relative to the message RAM
391 	 * msg_type == 0: the offset is relative to the data RAM (this is the
392 	 *                previous way of passing data)
393 	 * msg_type is anything else: there's critical hardware problem
394 	 */
395 	switch (msg_type) {
396 	case 1:
397 		ptr = priv->regs + DCPU_MSG_RAM_START + offset;
398 		break;
399 	case 0:
400 		ptr = priv->dmem + offset;
401 		break;
402 	default:
403 		dev_emerg(priv->dev, "invalid message reply from DCPU: %#x\n",
404 			response);
405 		if (buf && size)
406 			*size = sprintf(buf,
407 				"FATAL: communication error with DCPU\n");
408 	}
409 
410 	return ptr;
411 }
412 
413 static void __finalize_command(struct brcmstb_dpfe_priv *priv)
414 {
415 	unsigned int release_mbox;
416 
417 	/*
418 	 * It depends on the API version which MBOX register we have to write to
419 	 * to signal we are done.
420 	 */
421 	release_mbox = (priv->dpfe_api->version < 2)
422 			? REG_TO_HOST_MBOX : REG_TO_DCPU_MBOX;
423 	writel_relaxed(0, priv->regs + release_mbox);
424 }
425 
426 static int __send_command(struct brcmstb_dpfe_priv *priv, unsigned int cmd,
427 			  u32 result[])
428 {
429 	const u32 *msg = priv->dpfe_api->command[cmd];
430 	void __iomem *regs = priv->regs;
431 	unsigned int i, chksum, chksum_idx;
432 	int ret = 0;
433 	u32 resp;
434 
435 	if (cmd >= DPFE_CMD_MAX)
436 		return -1;
437 
438 	mutex_lock(&priv->lock);
439 
440 	/* Wait for DCPU to become ready */
441 	for (i = 0; i < DELAY_LOOP_MAX; i++) {
442 		resp = readl_relaxed(regs + REG_TO_HOST_MBOX);
443 		if (resp == 0)
444 			break;
445 		msleep(1);
446 	}
447 	if (resp != 0) {
448 		mutex_unlock(&priv->lock);
449 		return -ETIMEDOUT;
450 	}
451 
452 	/* Compute checksum over the message */
453 	chksum_idx = msg[MSG_ARG_COUNT] + MSG_ARG_COUNT + 1;
454 	chksum = get_msg_chksum(msg, chksum_idx);
455 
456 	/* Write command and arguments to message area */
457 	for (i = 0; i < MSG_FIELD_MAX; i++) {
458 		if (i == chksum_idx)
459 			writel_relaxed(chksum, regs + DCPU_MSG_RAM(i));
460 		else
461 			writel_relaxed(msg[i], regs + DCPU_MSG_RAM(i));
462 	}
463 
464 	/* Tell DCPU there is a command waiting */
465 	writel_relaxed(1, regs + REG_TO_DCPU_MBOX);
466 
467 	/* Wait for DCPU to process the command */
468 	for (i = 0; i < DELAY_LOOP_MAX; i++) {
469 		/* Read response code */
470 		resp = readl_relaxed(regs + REG_TO_HOST_MBOX);
471 		if (resp > 0)
472 			break;
473 		msleep(1);
474 	}
475 
476 	if (i == DELAY_LOOP_MAX) {
477 		resp = (DCPU_RET_ERR_TIMEDOUT & ~DCPU_RET_ERROR_BIT);
478 		ret = -ffs(resp);
479 	} else {
480 		/* Read response data */
481 		for (i = 0; i < MSG_FIELD_MAX; i++)
482 			result[i] = readl_relaxed(regs + DCPU_MSG_RAM(i));
483 		chksum_idx = result[MSG_ARG_COUNT] + MSG_ARG_COUNT + 1;
484 	}
485 
486 	/* Tell DCPU we are done */
487 	__finalize_command(priv);
488 
489 	mutex_unlock(&priv->lock);
490 
491 	if (ret)
492 		return ret;
493 
494 	/* Verify response */
495 	chksum = get_msg_chksum(result, chksum_idx);
496 	if (chksum != result[chksum_idx])
497 		resp = DCPU_RET_ERR_CHKSUM;
498 
499 	if (resp != DCPU_RET_SUCCESS) {
500 		resp &= ~DCPU_RET_ERROR_BIT;
501 		ret = -ffs(resp);
502 	}
503 
504 	return ret;
505 }
506 
507 /* Ensure that the firmware file loaded meets all the requirements. */
508 static int __verify_firmware(struct init_data *init,
509 			     const struct firmware *fw)
510 {
511 	const struct dpfe_firmware_header *header = (void *)fw->data;
512 	unsigned int dmem_size, imem_size, total_size;
513 	bool is_big_endian = false;
514 	const u32 *chksum_ptr;
515 
516 	if (header->magic == DPFE_BE_MAGIC)
517 		is_big_endian = true;
518 	else if (header->magic != DPFE_LE_MAGIC)
519 		return ERR_INVALID_MAGIC;
520 
521 	if (is_big_endian) {
522 		dmem_size = be32_to_cpu(header->dmem_size);
523 		imem_size = be32_to_cpu(header->imem_size);
524 	} else {
525 		dmem_size = le32_to_cpu(header->dmem_size);
526 		imem_size = le32_to_cpu(header->imem_size);
527 	}
528 
529 	/* Data and instruction sections are 32 bit words. */
530 	if ((dmem_size % sizeof(u32)) != 0 || (imem_size % sizeof(u32)) != 0)
531 		return ERR_INVALID_SIZE;
532 
533 	/*
534 	 * The header + the data section + the instruction section + the
535 	 * checksum must be equal to the total firmware size.
536 	 */
537 	total_size = dmem_size + imem_size + sizeof(*header) +
538 		sizeof(*chksum_ptr);
539 	if (total_size != fw->size)
540 		return ERR_INVALID_SIZE;
541 
542 	/* The checksum comes at the very end. */
543 	chksum_ptr = (void *)fw->data + sizeof(*header) + dmem_size + imem_size;
544 
545 	init->is_big_endian = is_big_endian;
546 	init->dmem_len = dmem_size;
547 	init->imem_len = imem_size;
548 	init->chksum = (is_big_endian)
549 		? be32_to_cpu(*chksum_ptr) : le32_to_cpu(*chksum_ptr);
550 
551 	return 0;
552 }
553 
554 /* Verify checksum by reading back the firmware from co-processor RAM. */
555 static int __verify_fw_checksum(struct init_data *init,
556 				struct brcmstb_dpfe_priv *priv,
557 				const struct dpfe_firmware_header *header,
558 				u32 checksum)
559 {
560 	u32 magic, sequence, version, sum;
561 	u32 __iomem *dmem = priv->dmem;
562 	u32 __iomem *imem = priv->imem;
563 	unsigned int i;
564 
565 	if (init->is_big_endian) {
566 		magic = be32_to_cpu(header->magic);
567 		sequence = be32_to_cpu(header->sequence);
568 		version = be32_to_cpu(header->version);
569 	} else {
570 		magic = le32_to_cpu(header->magic);
571 		sequence = le32_to_cpu(header->sequence);
572 		version = le32_to_cpu(header->version);
573 	}
574 
575 	sum = magic + sequence + version + init->dmem_len + init->imem_len;
576 
577 	for (i = 0; i < init->dmem_len / sizeof(u32); i++)
578 		sum += readl_relaxed(dmem + i);
579 
580 	for (i = 0; i < init->imem_len / sizeof(u32); i++)
581 		sum += readl_relaxed(imem + i);
582 
583 	return (sum == checksum) ? 0 : -1;
584 }
585 
586 static int __write_firmware(u32 __iomem *mem, const u32 *fw,
587 			    unsigned int size, bool is_big_endian)
588 {
589 	unsigned int i;
590 
591 	/* Convert size to 32-bit words. */
592 	size /= sizeof(u32);
593 
594 	/* It is recommended to clear the firmware area first. */
595 	for (i = 0; i < size; i++)
596 		writel_relaxed(0, mem + i);
597 
598 	/* Now copy it. */
599 	if (is_big_endian) {
600 		for (i = 0; i < size; i++)
601 			writel_relaxed(be32_to_cpu(fw[i]), mem + i);
602 	} else {
603 		for (i = 0; i < size; i++)
604 			writel_relaxed(le32_to_cpu(fw[i]), mem + i);
605 	}
606 
607 	return 0;
608 }
609 
610 static int brcmstb_dpfe_download_firmware(struct brcmstb_dpfe_priv *priv)
611 {
612 	const struct dpfe_firmware_header *header;
613 	unsigned int dmem_size, imem_size;
614 	struct device *dev = priv->dev;
615 	bool is_big_endian = false;
616 	const struct firmware *fw;
617 	const u32 *dmem, *imem;
618 	struct init_data init;
619 	const void *fw_blob;
620 	int ret;
621 
622 	/*
623 	 * Skip downloading the firmware if the DCPU is already running and
624 	 * responding to commands.
625 	 */
626 	if (is_dcpu_enabled(priv)) {
627 		u32 response[MSG_FIELD_MAX];
628 
629 		ret = __send_command(priv, DPFE_CMD_GET_INFO, response);
630 		if (!ret)
631 			return 0;
632 	}
633 
634 	/*
635 	 * If the firmware filename is NULL it means the boot firmware has to
636 	 * download the DCPU firmware for us. If that didn't work, we have to
637 	 * bail, since downloading it ourselves wouldn't work either.
638 	 */
639 	if (!priv->dpfe_api->fw_name)
640 		return -ENODEV;
641 
642 	ret = firmware_request_nowarn(&fw, priv->dpfe_api->fw_name, dev);
643 	/*
644 	 * Defer the firmware download if the firmware file couldn't be found.
645 	 * The root file system may not be available yet.
646 	 */
647 	if (ret)
648 		return (ret == -ENOENT) ? -EPROBE_DEFER : ret;
649 
650 	ret = __verify_firmware(&init, fw);
651 	if (ret)
652 		return -EFAULT;
653 
654 	__disable_dcpu(priv);
655 
656 	is_big_endian = init.is_big_endian;
657 	dmem_size = init.dmem_len;
658 	imem_size = init.imem_len;
659 
660 	/* At the beginning of the firmware blob is a header. */
661 	header = (struct dpfe_firmware_header *)fw->data;
662 	/* Void pointer to the beginning of the actual firmware. */
663 	fw_blob = fw->data + sizeof(*header);
664 	/* IMEM comes right after the header. */
665 	imem = fw_blob;
666 	/* DMEM follows after IMEM. */
667 	dmem = fw_blob + imem_size;
668 
669 	ret = __write_firmware(priv->dmem, dmem, dmem_size, is_big_endian);
670 	if (ret)
671 		return ret;
672 	ret = __write_firmware(priv->imem, imem, imem_size, is_big_endian);
673 	if (ret)
674 		return ret;
675 
676 	ret = __verify_fw_checksum(&init, priv, header, init.chksum);
677 	if (ret)
678 		return ret;
679 
680 	__enable_dcpu(priv);
681 
682 	return 0;
683 }
684 
685 static ssize_t generic_show(unsigned int command, u32 response[],
686 			    struct brcmstb_dpfe_priv *priv, char *buf)
687 {
688 	int ret;
689 
690 	if (!priv)
691 		return sprintf(buf, "ERROR: driver private data not set\n");
692 
693 	ret = __send_command(priv, command, response);
694 	if (ret < 0)
695 		return sprintf(buf, "ERROR: %s\n", error_text[-ret]);
696 
697 	return 0;
698 }
699 
700 static ssize_t show_info(struct device *dev, struct device_attribute *devattr,
701 			 char *buf)
702 {
703 	u32 response[MSG_FIELD_MAX];
704 	struct brcmstb_dpfe_priv *priv;
705 	unsigned int info;
706 	ssize_t ret;
707 
708 	priv = dev_get_drvdata(dev);
709 	ret = generic_show(DPFE_CMD_GET_INFO, response, priv, buf);
710 	if (ret)
711 		return ret;
712 
713 	info = response[MSG_ARG0];
714 
715 	return sprintf(buf, "%u.%u.%u.%u\n",
716 		       (info >> 24) & 0xff,
717 		       (info >> 16) & 0xff,
718 		       (info >> 8) & 0xff,
719 		       info & 0xff);
720 }
721 
722 static ssize_t show_refresh(struct device *dev,
723 			    struct device_attribute *devattr, char *buf)
724 {
725 	u32 response[MSG_FIELD_MAX];
726 	void __iomem *info;
727 	struct brcmstb_dpfe_priv *priv;
728 	u8 refresh, sr_abort, ppre, thermal_offs, tuf;
729 	u32 mr4;
730 	ssize_t ret;
731 
732 	priv = dev_get_drvdata(dev);
733 	ret = generic_show(DPFE_CMD_GET_REFRESH, response, priv, buf);
734 	if (ret)
735 		return ret;
736 
737 	info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
738 	if (!info)
739 		return ret;
740 
741 	mr4 = (readl_relaxed(info + DRAM_INFO_MR4) >> DRAM_INFO_MR4_SHIFT) &
742 	       DRAM_INFO_MR4_MASK;
743 
744 	refresh = (mr4 >> DRAM_MR4_REFRESH) & DRAM_MR4_REFRESH_MASK;
745 	sr_abort = (mr4 >> DRAM_MR4_SR_ABORT) & DRAM_MR4_SR_ABORT_MASK;
746 	ppre = (mr4 >> DRAM_MR4_PPRE) & DRAM_MR4_PPRE_MASK;
747 	thermal_offs = (mr4 >> DRAM_MR4_TH_OFFS) & DRAM_MR4_TH_OFFS_MASK;
748 	tuf = (mr4 >> DRAM_MR4_TUF) & DRAM_MR4_TUF_MASK;
749 
750 	return sprintf(buf, "%#x %#x %#x %#x %#x %#x %#x\n",
751 		       readl_relaxed(info + DRAM_INFO_INTERVAL),
752 		       refresh, sr_abort, ppre, thermal_offs, tuf,
753 		       readl_relaxed(info + DRAM_INFO_ERROR));
754 }
755 
756 static ssize_t store_refresh(struct device *dev, struct device_attribute *attr,
757 			  const char *buf, size_t count)
758 {
759 	u32 response[MSG_FIELD_MAX];
760 	struct brcmstb_dpfe_priv *priv;
761 	void __iomem *info;
762 	unsigned long val;
763 	int ret;
764 
765 	if (kstrtoul(buf, 0, &val) < 0)
766 		return -EINVAL;
767 
768 	priv = dev_get_drvdata(dev);
769 	ret = __send_command(priv, DPFE_CMD_GET_REFRESH, response);
770 	if (ret)
771 		return ret;
772 
773 	info = get_msg_ptr(priv, response[MSG_ARG0], NULL, NULL);
774 	if (!info)
775 		return -EIO;
776 
777 	writel_relaxed(val, info + DRAM_INFO_INTERVAL);
778 
779 	return count;
780 }
781 
782 static ssize_t show_vendor(struct device *dev, struct device_attribute *devattr,
783 			   char *buf)
784 {
785 	u32 response[MSG_FIELD_MAX];
786 	struct brcmstb_dpfe_priv *priv;
787 	void __iomem *info;
788 	ssize_t ret;
789 	u32 mr5, mr6, mr7, mr8, err;
790 
791 	priv = dev_get_drvdata(dev);
792 	ret = generic_show(DPFE_CMD_GET_VENDOR, response, priv, buf);
793 	if (ret)
794 		return ret;
795 
796 	info = get_msg_ptr(priv, response[MSG_ARG0], buf, &ret);
797 	if (!info)
798 		return ret;
799 
800 	mr5 = (readl_relaxed(info + DRAM_VENDOR_MR5) >> DRAM_VENDOR_SHIFT) &
801 		DRAM_VENDOR_MASK;
802 	mr6 = (readl_relaxed(info + DRAM_VENDOR_MR6) >> DRAM_VENDOR_SHIFT) &
803 		DRAM_VENDOR_MASK;
804 	mr7 = (readl_relaxed(info + DRAM_VENDOR_MR7) >> DRAM_VENDOR_SHIFT) &
805 		DRAM_VENDOR_MASK;
806 	mr8 = (readl_relaxed(info + DRAM_VENDOR_MR8) >> DRAM_VENDOR_SHIFT) &
807 		DRAM_VENDOR_MASK;
808 	err = readl_relaxed(info + DRAM_VENDOR_ERROR) & DRAM_VENDOR_MASK;
809 
810 	return sprintf(buf, "%#x %#x %#x %#x %#x\n", mr5, mr6, mr7, mr8, err);
811 }
812 
813 static ssize_t show_dram(struct device *dev, struct device_attribute *devattr,
814 			 char *buf)
815 {
816 	u32 response[MSG_FIELD_MAX];
817 	struct brcmstb_dpfe_priv *priv;
818 	ssize_t ret;
819 	u32 mr4, mr5, mr6, mr7, mr8, err;
820 
821 	priv = dev_get_drvdata(dev);
822 	ret = generic_show(DPFE_CMD_GET_REFRESH, response, priv, buf);
823 	if (ret)
824 		return ret;
825 
826 	mr4 = response[MSG_ARG0 + 0] & DRAM_INFO_MR4_MASK;
827 	mr5 = response[MSG_ARG0 + 1] & DRAM_DDR_INFO_MASK;
828 	mr6 = response[MSG_ARG0 + 2] & DRAM_DDR_INFO_MASK;
829 	mr7 = response[MSG_ARG0 + 3] & DRAM_DDR_INFO_MASK;
830 	mr8 = response[MSG_ARG0 + 4] & DRAM_DDR_INFO_MASK;
831 	err = response[MSG_ARG0 + 5] & DRAM_DDR_INFO_MASK;
832 
833 	return sprintf(buf, "%#x %#x %#x %#x %#x %#x\n", mr4, mr5, mr6, mr7,
834 			mr8, err);
835 }
836 
837 static int brcmstb_dpfe_resume(struct platform_device *pdev)
838 {
839 	struct brcmstb_dpfe_priv *priv = platform_get_drvdata(pdev);
840 
841 	return brcmstb_dpfe_download_firmware(priv);
842 }
843 
844 static int brcmstb_dpfe_probe(struct platform_device *pdev)
845 {
846 	struct device *dev = &pdev->dev;
847 	struct brcmstb_dpfe_priv *priv;
848 	struct resource *res;
849 	int ret;
850 
851 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
852 	if (!priv)
853 		return -ENOMEM;
854 
855 	priv->dev = dev;
856 
857 	mutex_init(&priv->lock);
858 	platform_set_drvdata(pdev, priv);
859 
860 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-cpu");
861 	priv->regs = devm_ioremap_resource(dev, res);
862 	if (IS_ERR(priv->regs)) {
863 		dev_err(dev, "couldn't map DCPU registers\n");
864 		return -ENODEV;
865 	}
866 
867 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-dmem");
868 	priv->dmem = devm_ioremap_resource(dev, res);
869 	if (IS_ERR(priv->dmem)) {
870 		dev_err(dev, "Couldn't map DCPU data memory\n");
871 		return -ENOENT;
872 	}
873 
874 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpfe-imem");
875 	priv->imem = devm_ioremap_resource(dev, res);
876 	if (IS_ERR(priv->imem)) {
877 		dev_err(dev, "Couldn't map DCPU instruction memory\n");
878 		return -ENOENT;
879 	}
880 
881 	priv->dpfe_api = of_device_get_match_data(dev);
882 	if (unlikely(!priv->dpfe_api)) {
883 		/*
884 		 * It should be impossible to end up here, but to be safe we
885 		 * check anyway.
886 		 */
887 		dev_err(dev, "Couldn't determine API\n");
888 		return -ENOENT;
889 	}
890 
891 	ret = brcmstb_dpfe_download_firmware(priv);
892 	if (ret) {
893 		if (ret != -EPROBE_DEFER)
894 			dev_err(dev, "Couldn't download firmware -- %d\n", ret);
895 		return ret;
896 	}
897 
898 	ret = sysfs_create_groups(&pdev->dev.kobj, priv->dpfe_api->sysfs_attrs);
899 	if (!ret)
900 		dev_info(dev, "registered with API v%d.\n",
901 			 priv->dpfe_api->version);
902 
903 	return ret;
904 }
905 
906 static int brcmstb_dpfe_remove(struct platform_device *pdev)
907 {
908 	struct brcmstb_dpfe_priv *priv = dev_get_drvdata(&pdev->dev);
909 
910 	sysfs_remove_groups(&pdev->dev.kobj, priv->dpfe_api->sysfs_attrs);
911 
912 	return 0;
913 }
914 
915 static const struct of_device_id brcmstb_dpfe_of_match[] = {
916 	/* Use legacy API v2 for a select number of chips */
917 	{ .compatible = "brcm,bcm7268-dpfe-cpu", .data = &dpfe_api_old_v2 },
918 	{ .compatible = "brcm,bcm7271-dpfe-cpu", .data = &dpfe_api_old_v2 },
919 	{ .compatible = "brcm,bcm7278-dpfe-cpu", .data = &dpfe_api_old_v2 },
920 	{ .compatible = "brcm,bcm7211-dpfe-cpu", .data = &dpfe_api_new_v2 },
921 	/* API v3 is the default going forward */
922 	{ .compatible = "brcm,dpfe-cpu", .data = &dpfe_api_v3 },
923 	{}
924 };
925 MODULE_DEVICE_TABLE(of, brcmstb_dpfe_of_match);
926 
927 static struct platform_driver brcmstb_dpfe_driver = {
928 	.driver	= {
929 		.name = DRVNAME,
930 		.of_match_table = brcmstb_dpfe_of_match,
931 	},
932 	.probe = brcmstb_dpfe_probe,
933 	.remove	= brcmstb_dpfe_remove,
934 	.resume = brcmstb_dpfe_resume,
935 };
936 
937 module_platform_driver(brcmstb_dpfe_driver);
938 
939 MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
940 MODULE_DESCRIPTION("BRCMSTB DDR PHY Front End Driver");
941 MODULE_LICENSE("GPL");
942