xref: /linux/drivers/edac/fsl_ddr_edac.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Freescale Memory Controller kernel module
4  *
5  * Support Power-based SoCs including MPC85xx, MPC86xx, MPC83xx and
6  * ARM-based Layerscape SoCs including LS2xxx and LS1021A. Originally
7  * split out from mpc85xx_edac EDAC driver.
8  *
9  * Parts Copyrighted (c) 2013 by Freescale Semiconductor, Inc.
10  *
11  * Author: Dave Jiang <djiang@mvista.com>
12  *
13  * 2006-2007 (c) MontaVista Software, Inc.
14  */
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/ctype.h>
19 #include <linux/io.h>
20 #include <linux/mod_devicetable.h>
21 #include <linux/edac.h>
22 #include <linux/smp.h>
23 #include <linux/gfp.h>
24 
25 #include <linux/of.h>
26 #include <linux/of_address.h>
27 #include "edac_module.h"
28 #include "fsl_ddr_edac.h"
29 
30 #define EDAC_MOD_STR	"fsl_ddr_edac"
31 
32 static int edac_mc_idx;
33 
34 static inline void __iomem *ddr_reg_addr(struct fsl_mc_pdata *pdata, unsigned int off)
35 {
36 	if (pdata->flag == TYPE_IMX9 && off >= FSL_MC_DATA_ERR_INJECT_HI && off <= FSL_MC_ERR_SBE)
37 		return pdata->inject_vbase + off - FSL_MC_DATA_ERR_INJECT_HI
38 		       + IMX9_MC_DATA_ERR_INJECT_OFF;
39 
40 	if (pdata->flag == TYPE_IMX9 && off >= IMX9_MC_ERR_EN)
41 		return pdata->inject_vbase + off - IMX9_MC_ERR_EN;
42 
43 	return pdata->mc_vbase + off;
44 }
45 
46 static inline u32 ddr_in32(struct fsl_mc_pdata *pdata, unsigned int off)
47 {
48 	void __iomem *addr = ddr_reg_addr(pdata, off);
49 
50 	return pdata->little_endian ? ioread32(addr) : ioread32be(addr);
51 }
52 
53 static inline void ddr_out32(struct fsl_mc_pdata *pdata, unsigned int off, u32 value)
54 {
55 	void __iomem *addr = ddr_reg_addr(pdata, off);
56 
57 	if (pdata->little_endian)
58 		iowrite32(value, addr);
59 	else
60 		iowrite32be(value, addr);
61 }
62 
63 #ifdef CONFIG_EDAC_DEBUG
64 /************************ MC SYSFS parts ***********************************/
65 
66 #define to_mci(k) container_of(k, struct mem_ctl_info, dev)
67 
68 static ssize_t fsl_mc_inject_data_hi_show(struct device *dev,
69 					  struct device_attribute *mattr,
70 					  char *data)
71 {
72 	struct mem_ctl_info *mci = to_mci(dev);
73 	struct fsl_mc_pdata *pdata = mci->pvt_info;
74 	return sprintf(data, "0x%08x",
75 		       ddr_in32(pdata, FSL_MC_DATA_ERR_INJECT_HI));
76 }
77 
78 static ssize_t fsl_mc_inject_data_lo_show(struct device *dev,
79 					  struct device_attribute *mattr,
80 					      char *data)
81 {
82 	struct mem_ctl_info *mci = to_mci(dev);
83 	struct fsl_mc_pdata *pdata = mci->pvt_info;
84 	return sprintf(data, "0x%08x",
85 		       ddr_in32(pdata, FSL_MC_DATA_ERR_INJECT_LO));
86 }
87 
88 static ssize_t fsl_mc_inject_ctrl_show(struct device *dev,
89 				       struct device_attribute *mattr,
90 					   char *data)
91 {
92 	struct mem_ctl_info *mci = to_mci(dev);
93 	struct fsl_mc_pdata *pdata = mci->pvt_info;
94 	return sprintf(data, "0x%08x",
95 		       ddr_in32(pdata, FSL_MC_ECC_ERR_INJECT));
96 }
97 
98 static ssize_t fsl_mc_inject_data_hi_store(struct device *dev,
99 					   struct device_attribute *mattr,
100 					       const char *data, size_t count)
101 {
102 	struct mem_ctl_info *mci = to_mci(dev);
103 	struct fsl_mc_pdata *pdata = mci->pvt_info;
104 	unsigned long val;
105 	int rc;
106 
107 	if (isdigit(*data)) {
108 		rc = kstrtoul(data, 0, &val);
109 		if (rc)
110 			return rc;
111 
112 		ddr_out32(pdata, FSL_MC_DATA_ERR_INJECT_HI, val);
113 		return count;
114 	}
115 	return 0;
116 }
117 
118 static ssize_t fsl_mc_inject_data_lo_store(struct device *dev,
119 					   struct device_attribute *mattr,
120 					       const char *data, size_t count)
121 {
122 	struct mem_ctl_info *mci = to_mci(dev);
123 	struct fsl_mc_pdata *pdata = mci->pvt_info;
124 	unsigned long val;
125 	int rc;
126 
127 	if (isdigit(*data)) {
128 		rc = kstrtoul(data, 0, &val);
129 		if (rc)
130 			return rc;
131 
132 		ddr_out32(pdata, FSL_MC_DATA_ERR_INJECT_LO, val);
133 		return count;
134 	}
135 	return 0;
136 }
137 
138 static ssize_t fsl_mc_inject_ctrl_store(struct device *dev,
139 					struct device_attribute *mattr,
140 					       const char *data, size_t count)
141 {
142 	struct mem_ctl_info *mci = to_mci(dev);
143 	struct fsl_mc_pdata *pdata = mci->pvt_info;
144 	unsigned long val;
145 	int rc;
146 
147 	if (isdigit(*data)) {
148 		rc = kstrtoul(data, 0, &val);
149 		if (rc)
150 			return rc;
151 
152 		ddr_out32(pdata, FSL_MC_ECC_ERR_INJECT, val);
153 		return count;
154 	}
155 	return 0;
156 }
157 
158 static DEVICE_ATTR(inject_data_hi, S_IRUGO | S_IWUSR,
159 		   fsl_mc_inject_data_hi_show, fsl_mc_inject_data_hi_store);
160 static DEVICE_ATTR(inject_data_lo, S_IRUGO | S_IWUSR,
161 		   fsl_mc_inject_data_lo_show, fsl_mc_inject_data_lo_store);
162 static DEVICE_ATTR(inject_ctrl, S_IRUGO | S_IWUSR,
163 		   fsl_mc_inject_ctrl_show, fsl_mc_inject_ctrl_store);
164 #endif /* CONFIG_EDAC_DEBUG */
165 
166 static struct attribute *fsl_ddr_dev_attrs[] = {
167 #ifdef CONFIG_EDAC_DEBUG
168 	&dev_attr_inject_data_hi.attr,
169 	&dev_attr_inject_data_lo.attr,
170 	&dev_attr_inject_ctrl.attr,
171 #endif
172 	NULL
173 };
174 
175 ATTRIBUTE_GROUPS(fsl_ddr_dev);
176 
177 /**************************** MC Err device ***************************/
178 
179 /*
180  * Taken from table 8-55 in the MPC8641 User's Manual and/or 9-61 in the
181  * MPC8572 User's Manual.  Each line represents a syndrome bit column as a
182  * 64-bit value, but split into an upper and lower 32-bit chunk.  The labels
183  * below correspond to Freescale's manuals.
184  */
185 static unsigned int ecc_table[16] = {
186 	/* MSB           LSB */
187 	/* [0:31]    [32:63] */
188 	0xf00fe11e, 0xc33c0ff7,	/* Syndrome bit 7 */
189 	0x00ff00ff, 0x00fff0ff,
190 	0x0f0f0f0f, 0x0f0fff00,
191 	0x11113333, 0x7777000f,
192 	0x22224444, 0x8888222f,
193 	0x44448888, 0xffff4441,
194 	0x8888ffff, 0x11118882,
195 	0xffff1111, 0x22221114,	/* Syndrome bit 0 */
196 };
197 
198 /*
199  * Calculate the correct ECC value for a 64-bit value specified by high:low
200  */
201 static u8 calculate_ecc(u32 high, u32 low)
202 {
203 	u32 mask_low;
204 	u32 mask_high;
205 	int bit_cnt;
206 	u8 ecc = 0;
207 	int i;
208 	int j;
209 
210 	for (i = 0; i < 8; i++) {
211 		mask_high = ecc_table[i * 2];
212 		mask_low = ecc_table[i * 2 + 1];
213 		bit_cnt = 0;
214 
215 		for (j = 0; j < 32; j++) {
216 			if ((mask_high >> j) & 1)
217 				bit_cnt ^= (high >> j) & 1;
218 			if ((mask_low >> j) & 1)
219 				bit_cnt ^= (low >> j) & 1;
220 		}
221 
222 		ecc |= bit_cnt << i;
223 	}
224 
225 	return ecc;
226 }
227 
228 /*
229  * Create the syndrome code which is generated if the data line specified by
230  * 'bit' failed.  Eg generate an 8-bit codes seen in Table 8-55 in the MPC8641
231  * User's Manual and 9-61 in the MPC8572 User's Manual.
232  */
233 static u8 syndrome_from_bit(unsigned int bit) {
234 	int i;
235 	u8 syndrome = 0;
236 
237 	/*
238 	 * Cycle through the upper or lower 32-bit portion of each value in
239 	 * ecc_table depending on if 'bit' is in the upper or lower half of
240 	 * 64-bit data.
241 	 */
242 	for (i = bit < 32; i < 16; i += 2)
243 		syndrome |= ((ecc_table[i] >> (bit % 32)) & 1) << (i / 2);
244 
245 	return syndrome;
246 }
247 
248 /*
249  * Decode data and ecc syndrome to determine what went wrong
250  * Note: This can only decode single-bit errors
251  */
252 static void sbe_ecc_decode(u32 cap_high, u32 cap_low, u32 cap_ecc,
253 		       int *bad_data_bit, int *bad_ecc_bit)
254 {
255 	int i;
256 	u8 syndrome;
257 
258 	*bad_data_bit = -1;
259 	*bad_ecc_bit = -1;
260 
261 	/*
262 	 * Calculate the ECC of the captured data and XOR it with the captured
263 	 * ECC to find an ECC syndrome value we can search for
264 	 */
265 	syndrome = calculate_ecc(cap_high, cap_low) ^ cap_ecc;
266 
267 	/* Check if a data line is stuck... */
268 	for (i = 0; i < 64; i++) {
269 		if (syndrome == syndrome_from_bit(i)) {
270 			*bad_data_bit = i;
271 			return;
272 		}
273 	}
274 
275 	/* If data is correct, check ECC bits for errors... */
276 	for (i = 0; i < 8; i++) {
277 		if ((syndrome >> i) & 0x1) {
278 			*bad_ecc_bit = i;
279 			return;
280 		}
281 	}
282 }
283 
284 #define make64(high, low) (((u64)(high) << 32) | (low))
285 
286 static void fsl_mc_check(struct mem_ctl_info *mci)
287 {
288 	struct fsl_mc_pdata *pdata = mci->pvt_info;
289 	struct csrow_info *csrow;
290 	u32 bus_width;
291 	u32 err_detect;
292 	u32 syndrome;
293 	u64 err_addr;
294 	u32 pfn;
295 	int row_index;
296 	u32 cap_high;
297 	u32 cap_low;
298 	int bad_data_bit;
299 	int bad_ecc_bit;
300 
301 	err_detect = ddr_in32(pdata, FSL_MC_ERR_DETECT);
302 	if (!err_detect)
303 		return;
304 
305 	fsl_mc_printk(mci, KERN_ERR, "Err Detect Register: %#8.8x\n",
306 		      err_detect);
307 
308 	/* no more processing if not ECC bit errors */
309 	if (!(err_detect & (DDR_EDE_SBE | DDR_EDE_MBE))) {
310 		ddr_out32(pdata, FSL_MC_ERR_DETECT, err_detect);
311 		return;
312 	}
313 
314 	syndrome = ddr_in32(pdata, FSL_MC_CAPTURE_ECC);
315 
316 	/* Mask off appropriate bits of syndrome based on bus width */
317 	bus_width = (ddr_in32(pdata, FSL_MC_DDR_SDRAM_CFG) &
318 		     DSC_DBW_MASK) ? 32 : 64;
319 	if (bus_width == 64)
320 		syndrome &= 0xff;
321 	else
322 		syndrome &= 0xffff;
323 
324 	err_addr = make64(
325 		ddr_in32(pdata, FSL_MC_CAPTURE_EXT_ADDRESS),
326 		ddr_in32(pdata, FSL_MC_CAPTURE_ADDRESS));
327 	pfn = err_addr >> PAGE_SHIFT;
328 
329 	for (row_index = 0; row_index < mci->nr_csrows; row_index++) {
330 		csrow = mci->csrows[row_index];
331 		if ((pfn >= csrow->first_page) && (pfn <= csrow->last_page))
332 			break;
333 	}
334 
335 	cap_high = ddr_in32(pdata, FSL_MC_CAPTURE_DATA_HI);
336 	cap_low = ddr_in32(pdata, FSL_MC_CAPTURE_DATA_LO);
337 
338 	/*
339 	 * Analyze single-bit errors on 64-bit wide buses
340 	 * TODO: Add support for 32-bit wide buses
341 	 */
342 	if ((err_detect & DDR_EDE_SBE) && (bus_width == 64)) {
343 		u64 cap = (u64)cap_high << 32 | cap_low;
344 		u32 s = syndrome;
345 
346 		sbe_ecc_decode(cap_high, cap_low, syndrome,
347 				&bad_data_bit, &bad_ecc_bit);
348 
349 		if (bad_data_bit >= 0) {
350 			fsl_mc_printk(mci, KERN_ERR, "Faulty Data bit: %d\n", bad_data_bit);
351 			cap ^= 1ULL << bad_data_bit;
352 		}
353 
354 		if (bad_ecc_bit >= 0) {
355 			fsl_mc_printk(mci, KERN_ERR, "Faulty ECC bit: %d\n", bad_ecc_bit);
356 			s ^= 1 << bad_ecc_bit;
357 		}
358 
359 		fsl_mc_printk(mci, KERN_ERR,
360 			"Expected Data / ECC:\t%#8.8x_%08x / %#2.2x\n",
361 			upper_32_bits(cap), lower_32_bits(cap), s);
362 	}
363 
364 	fsl_mc_printk(mci, KERN_ERR,
365 			"Captured Data / ECC:\t%#8.8x_%08x / %#2.2x\n",
366 			cap_high, cap_low, syndrome);
367 	fsl_mc_printk(mci, KERN_ERR, "Err addr: %#8.8llx\n", err_addr);
368 	fsl_mc_printk(mci, KERN_ERR, "PFN: %#8.8x\n", pfn);
369 
370 	/* we are out of range */
371 	if (row_index == mci->nr_csrows)
372 		fsl_mc_printk(mci, KERN_ERR, "PFN out of range!\n");
373 
374 	if (err_detect & DDR_EDE_SBE)
375 		edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, 1,
376 				     pfn, err_addr & ~PAGE_MASK, syndrome,
377 				     row_index, 0, -1,
378 				     mci->ctl_name, "");
379 
380 	if (err_detect & DDR_EDE_MBE)
381 		edac_mc_handle_error(HW_EVENT_ERR_UNCORRECTED, mci, 1,
382 				     pfn, err_addr & ~PAGE_MASK, syndrome,
383 				     row_index, 0, -1,
384 				     mci->ctl_name, "");
385 
386 	ddr_out32(pdata, FSL_MC_ERR_DETECT, err_detect);
387 }
388 
389 static irqreturn_t fsl_mc_isr(int irq, void *dev_id)
390 {
391 	struct mem_ctl_info *mci = dev_id;
392 	struct fsl_mc_pdata *pdata = mci->pvt_info;
393 	u32 err_detect;
394 
395 	err_detect = ddr_in32(pdata, FSL_MC_ERR_DETECT);
396 	if (!err_detect)
397 		return IRQ_NONE;
398 
399 	fsl_mc_check(mci);
400 
401 	return IRQ_HANDLED;
402 }
403 
404 static void fsl_ddr_init_csrows(struct mem_ctl_info *mci)
405 {
406 	struct fsl_mc_pdata *pdata = mci->pvt_info;
407 	struct csrow_info *csrow;
408 	struct dimm_info *dimm;
409 	u32 sdram_ctl;
410 	u32 sdtype;
411 	enum mem_type mtype;
412 	u32 cs_bnds;
413 	int index;
414 
415 	sdram_ctl = ddr_in32(pdata, FSL_MC_DDR_SDRAM_CFG);
416 
417 	sdtype = sdram_ctl & DSC_SDTYPE_MASK;
418 	if (sdram_ctl & DSC_RD_EN) {
419 		switch (sdtype) {
420 		case 0x02000000:
421 			mtype = MEM_RDDR;
422 			break;
423 		case 0x03000000:
424 			mtype = MEM_RDDR2;
425 			break;
426 		case 0x07000000:
427 			mtype = MEM_RDDR3;
428 			break;
429 		case 0x05000000:
430 			mtype = MEM_RDDR4;
431 			break;
432 		default:
433 			mtype = MEM_UNKNOWN;
434 			break;
435 		}
436 	} else {
437 		switch (sdtype) {
438 		case 0x02000000:
439 			mtype = MEM_DDR;
440 			break;
441 		case 0x03000000:
442 			mtype = MEM_DDR2;
443 			break;
444 		case 0x07000000:
445 			mtype = MEM_DDR3;
446 			break;
447 		case 0x05000000:
448 			mtype = MEM_DDR4;
449 			break;
450 		case 0x04000000:
451 			mtype = MEM_LPDDR4;
452 			break;
453 		default:
454 			mtype = MEM_UNKNOWN;
455 			break;
456 		}
457 	}
458 
459 	for (index = 0; index < mci->nr_csrows; index++) {
460 		u32 start;
461 		u32 end;
462 
463 		csrow = mci->csrows[index];
464 		dimm = csrow->channels[0]->dimm;
465 
466 		cs_bnds = ddr_in32(pdata, FSL_MC_CS_BNDS_0 +
467 				   (index * FSL_MC_CS_BNDS_OFS));
468 
469 		start = (cs_bnds & 0xffff0000) >> 16;
470 		end   = (cs_bnds & 0x0000ffff);
471 
472 		if (start == end)
473 			continue;	/* not populated */
474 
475 		start <<= (24 - PAGE_SHIFT);
476 		end   <<= (24 - PAGE_SHIFT);
477 		end    |= (1 << (24 - PAGE_SHIFT)) - 1;
478 
479 		csrow->first_page = start;
480 		csrow->last_page = end;
481 
482 		dimm->nr_pages = end + 1 - start;
483 		dimm->grain = 8;
484 		dimm->mtype = mtype;
485 		dimm->dtype = DEV_UNKNOWN;
486 		if (pdata->flag == TYPE_IMX9)
487 			dimm->dtype = DEV_X16;
488 		else if (sdram_ctl & DSC_X32_EN)
489 			dimm->dtype = DEV_X32;
490 		dimm->edac_mode = EDAC_SECDED;
491 	}
492 }
493 
494 int fsl_mc_err_probe(struct platform_device *op)
495 {
496 	struct mem_ctl_info *mci;
497 	struct edac_mc_layer layers[2];
498 	struct fsl_mc_pdata *pdata;
499 	struct resource r;
500 	u32 ecc_en_mask;
501 	u32 sdram_ctl;
502 	int res;
503 
504 	if (!devres_open_group(&op->dev, fsl_mc_err_probe, GFP_KERNEL))
505 		return -ENOMEM;
506 
507 	layers[0].type = EDAC_MC_LAYER_CHIP_SELECT;
508 	layers[0].size = 4;
509 	layers[0].is_virt_csrow = true;
510 	layers[1].type = EDAC_MC_LAYER_CHANNEL;
511 	layers[1].size = 1;
512 	layers[1].is_virt_csrow = false;
513 	mci = edac_mc_alloc(edac_mc_idx, ARRAY_SIZE(layers), layers,
514 			    sizeof(*pdata));
515 	if (!mci) {
516 		devres_release_group(&op->dev, fsl_mc_err_probe);
517 		return -ENOMEM;
518 	}
519 
520 	pdata = mci->pvt_info;
521 	pdata->name = "fsl_mc_err";
522 	mci->pdev = &op->dev;
523 	pdata->edac_idx = edac_mc_idx++;
524 	dev_set_drvdata(mci->pdev, mci);
525 	mci->ctl_name = pdata->name;
526 	mci->dev_name = pdata->name;
527 
528 	pdata->flag = (unsigned long)device_get_match_data(&op->dev);
529 
530 	/*
531 	 * Get the endianness of DDR controller registers.
532 	 * Default is big endian.
533 	 */
534 	pdata->little_endian = of_property_read_bool(op->dev.of_node, "little-endian");
535 
536 	res = of_address_to_resource(op->dev.of_node, 0, &r);
537 	if (res) {
538 		pr_err("%s: Unable to get resource for MC err regs\n",
539 		       __func__);
540 		goto err;
541 	}
542 
543 	if (!devm_request_mem_region(&op->dev, r.start, resource_size(&r),
544 				     pdata->name)) {
545 		pr_err("%s: Error while requesting mem region\n",
546 		       __func__);
547 		res = -EBUSY;
548 		goto err;
549 	}
550 
551 	pdata->mc_vbase = devm_ioremap(&op->dev, r.start, resource_size(&r));
552 	if (!pdata->mc_vbase) {
553 		pr_err("%s: Unable to setup MC err regs\n", __func__);
554 		res = -ENOMEM;
555 		goto err;
556 	}
557 
558 	if (pdata->flag == TYPE_IMX9) {
559 		pdata->inject_vbase = devm_platform_ioremap_resource_byname(op, "inject");
560 		if (IS_ERR(pdata->inject_vbase)) {
561 			res = -ENOMEM;
562 			goto err;
563 		}
564 	}
565 
566 	if (pdata->flag == TYPE_IMX9) {
567 		sdram_ctl = ddr_in32(pdata, IMX9_MC_ERR_EN);
568 		ecc_en_mask = ERR_ECC_EN | ERR_INLINE_ECC;
569 	} else {
570 		sdram_ctl = ddr_in32(pdata, FSL_MC_DDR_SDRAM_CFG);
571 		ecc_en_mask = DSC_ECC_EN;
572 	}
573 
574 	if ((sdram_ctl & ecc_en_mask) != ecc_en_mask) {
575 		/* no ECC */
576 		pr_warn("%s: No ECC DIMMs discovered\n", __func__);
577 		res = -ENODEV;
578 		goto err;
579 	}
580 
581 	edac_dbg(3, "init mci\n");
582 	mci->mtype_cap = MEM_FLAG_DDR | MEM_FLAG_RDDR |
583 			 MEM_FLAG_DDR2 | MEM_FLAG_RDDR2 |
584 			 MEM_FLAG_DDR3 | MEM_FLAG_RDDR3 |
585 			 MEM_FLAG_DDR4 | MEM_FLAG_RDDR4 |
586 			 MEM_FLAG_LPDDR4;
587 	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
588 	mci->edac_cap = EDAC_FLAG_SECDED;
589 	mci->mod_name = EDAC_MOD_STR;
590 
591 	if (edac_op_state == EDAC_OPSTATE_POLL)
592 		mci->edac_check = fsl_mc_check;
593 
594 	mci->ctl_page_to_phys = NULL;
595 
596 	mci->scrub_mode = SCRUB_SW_SRC;
597 
598 	fsl_ddr_init_csrows(mci);
599 
600 	/* store the original error disable bits */
601 	pdata->orig_ddr_err_disable = ddr_in32(pdata, FSL_MC_ERR_DISABLE);
602 	ddr_out32(pdata, FSL_MC_ERR_DISABLE, 0);
603 
604 	/* clear all error bits */
605 	ddr_out32(pdata, FSL_MC_ERR_DETECT, ~0);
606 
607 	res = edac_mc_add_mc_with_groups(mci, fsl_ddr_dev_groups);
608 	if (res) {
609 		edac_dbg(3, "failed edac_mc_add_mc()\n");
610 		goto err;
611 	}
612 
613 	if (edac_op_state == EDAC_OPSTATE_INT) {
614 		ddr_out32(pdata, FSL_MC_ERR_INT_EN,
615 			  DDR_EIE_MBEE | DDR_EIE_SBEE);
616 
617 		/* store the original error management threshold */
618 		pdata->orig_ddr_err_sbe = ddr_in32(pdata,
619 						   FSL_MC_ERR_SBE) & 0xff0000;
620 
621 		/* set threshold to 1 error per interrupt */
622 		ddr_out32(pdata, FSL_MC_ERR_SBE, 0x10000);
623 
624 		/* register interrupts */
625 		pdata->irq = platform_get_irq(op, 0);
626 		res = devm_request_irq(&op->dev, pdata->irq,
627 				       fsl_mc_isr,
628 				       IRQF_SHARED,
629 				       "[EDAC] MC err", mci);
630 		if (res < 0) {
631 			pr_err("%s: Unable to request irq %d for FSL DDR DRAM ERR\n",
632 			       __func__, pdata->irq);
633 			res = -ENODEV;
634 			goto err2;
635 		}
636 
637 		pr_info(EDAC_MOD_STR " acquired irq %d for MC\n",
638 		       pdata->irq);
639 	}
640 
641 	devres_remove_group(&op->dev, fsl_mc_err_probe);
642 	edac_dbg(3, "success\n");
643 	pr_info(EDAC_MOD_STR " MC err registered\n");
644 
645 	return 0;
646 
647 err2:
648 	edac_mc_del_mc(&op->dev);
649 err:
650 	devres_release_group(&op->dev, fsl_mc_err_probe);
651 	edac_mc_free(mci);
652 	return res;
653 }
654 
655 void fsl_mc_err_remove(struct platform_device *op)
656 {
657 	struct mem_ctl_info *mci = dev_get_drvdata(&op->dev);
658 	struct fsl_mc_pdata *pdata = mci->pvt_info;
659 
660 	edac_dbg(0, "\n");
661 
662 	if (edac_op_state == EDAC_OPSTATE_INT) {
663 		ddr_out32(pdata, FSL_MC_ERR_INT_EN, 0);
664 	}
665 
666 	ddr_out32(pdata, FSL_MC_ERR_DISABLE,
667 		  pdata->orig_ddr_err_disable);
668 	ddr_out32(pdata, FSL_MC_ERR_SBE, pdata->orig_ddr_err_sbe);
669 
670 
671 	edac_mc_del_mc(&op->dev);
672 	edac_mc_free(mci);
673 }
674