xref: /openbmc/linux/drivers/memory/atmel-ebi.c (revision 538c7b5b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * EBI driver for Atmel chips
4  * inspired by the fsl weim bus driver
5  *
6  * Copyright (C) 2013 Jean-Jacques Hiblot <jjhiblot@traphandler.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/io.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/mfd/syscon/atmel-matrix.h>
13 #include <linux/mfd/syscon/atmel-smc.h>
14 #include <linux/init.h>
15 #include <linux/of_device.h>
16 #include <linux/regmap.h>
17 #include <soc/at91/atmel-sfr.h>
18 
19 #define AT91_EBI_NUM_CS		8
20 
21 struct atmel_ebi_dev_config {
22 	int cs;
23 	struct atmel_smc_cs_conf smcconf;
24 };
25 
26 struct atmel_ebi;
27 
28 struct atmel_ebi_dev {
29 	struct list_head node;
30 	struct atmel_ebi *ebi;
31 	u32 mode;
32 	int numcs;
33 	struct atmel_ebi_dev_config configs[];
34 };
35 
36 struct atmel_ebi_caps {
37 	unsigned int available_cs;
38 	unsigned int ebi_csa_offs;
39 	const char *regmap_name;
40 	void (*get_config)(struct atmel_ebi_dev *ebid,
41 			   struct atmel_ebi_dev_config *conf);
42 	int (*xlate_config)(struct atmel_ebi_dev *ebid,
43 			    struct device_node *configs_np,
44 			    struct atmel_ebi_dev_config *conf);
45 	void (*apply_config)(struct atmel_ebi_dev *ebid,
46 			     struct atmel_ebi_dev_config *conf);
47 };
48 
49 struct atmel_ebi {
50 	struct clk *clk;
51 	struct regmap *regmap;
52 	struct  {
53 		struct regmap *regmap;
54 		struct clk *clk;
55 		const struct atmel_hsmc_reg_layout *layout;
56 	} smc;
57 
58 	struct device *dev;
59 	const struct atmel_ebi_caps *caps;
60 	struct list_head devs;
61 };
62 
63 struct atmel_smc_timing_xlate {
64 	const char *name;
65 	int (*converter)(struct atmel_smc_cs_conf *conf,
66 			 unsigned int shift, unsigned int nycles);
67 	unsigned int shift;
68 };
69 
70 #define ATMEL_SMC_SETUP_XLATE(nm, pos)	\
71 	{ .name = nm, .converter = atmel_smc_cs_conf_set_setup, .shift = pos}
72 
73 #define ATMEL_SMC_PULSE_XLATE(nm, pos)	\
74 	{ .name = nm, .converter = atmel_smc_cs_conf_set_pulse, .shift = pos}
75 
76 #define ATMEL_SMC_CYCLE_XLATE(nm, pos)	\
77 	{ .name = nm, .converter = atmel_smc_cs_conf_set_cycle, .shift = pos}
78 
at91sam9_ebi_get_config(struct atmel_ebi_dev * ebid,struct atmel_ebi_dev_config * conf)79 static void at91sam9_ebi_get_config(struct atmel_ebi_dev *ebid,
80 				    struct atmel_ebi_dev_config *conf)
81 {
82 	atmel_smc_cs_conf_get(ebid->ebi->smc.regmap, conf->cs,
83 			      &conf->smcconf);
84 }
85 
sama5_ebi_get_config(struct atmel_ebi_dev * ebid,struct atmel_ebi_dev_config * conf)86 static void sama5_ebi_get_config(struct atmel_ebi_dev *ebid,
87 				 struct atmel_ebi_dev_config *conf)
88 {
89 	atmel_hsmc_cs_conf_get(ebid->ebi->smc.regmap, ebid->ebi->smc.layout,
90 			       conf->cs, &conf->smcconf);
91 }
92 
93 static const struct atmel_smc_timing_xlate timings_xlate_table[] = {
94 	ATMEL_SMC_SETUP_XLATE("atmel,smc-ncs-rd-setup-ns",
95 			      ATMEL_SMC_NCS_RD_SHIFT),
96 	ATMEL_SMC_SETUP_XLATE("atmel,smc-ncs-wr-setup-ns",
97 			      ATMEL_SMC_NCS_WR_SHIFT),
98 	ATMEL_SMC_SETUP_XLATE("atmel,smc-nrd-setup-ns", ATMEL_SMC_NRD_SHIFT),
99 	ATMEL_SMC_SETUP_XLATE("atmel,smc-nwe-setup-ns", ATMEL_SMC_NWE_SHIFT),
100 	ATMEL_SMC_PULSE_XLATE("atmel,smc-ncs-rd-pulse-ns",
101 			      ATMEL_SMC_NCS_RD_SHIFT),
102 	ATMEL_SMC_PULSE_XLATE("atmel,smc-ncs-wr-pulse-ns",
103 			      ATMEL_SMC_NCS_WR_SHIFT),
104 	ATMEL_SMC_PULSE_XLATE("atmel,smc-nrd-pulse-ns", ATMEL_SMC_NRD_SHIFT),
105 	ATMEL_SMC_PULSE_XLATE("atmel,smc-nwe-pulse-ns", ATMEL_SMC_NWE_SHIFT),
106 	ATMEL_SMC_CYCLE_XLATE("atmel,smc-nrd-cycle-ns", ATMEL_SMC_NRD_SHIFT),
107 	ATMEL_SMC_CYCLE_XLATE("atmel,smc-nwe-cycle-ns", ATMEL_SMC_NWE_SHIFT),
108 };
109 
atmel_ebi_xslate_smc_timings(struct atmel_ebi_dev * ebid,struct device_node * np,struct atmel_smc_cs_conf * smcconf)110 static int atmel_ebi_xslate_smc_timings(struct atmel_ebi_dev *ebid,
111 					struct device_node *np,
112 					struct atmel_smc_cs_conf *smcconf)
113 {
114 	unsigned int clk_rate = clk_get_rate(ebid->ebi->clk);
115 	unsigned int clk_period_ns = NSEC_PER_SEC / clk_rate;
116 	bool required = false;
117 	unsigned int ncycles;
118 	int ret, i;
119 	u32 val;
120 
121 	ret = of_property_read_u32(np, "atmel,smc-tdf-ns", &val);
122 	if (!ret) {
123 		required = true;
124 		ncycles = DIV_ROUND_UP(val, clk_period_ns);
125 		if (ncycles > ATMEL_SMC_MODE_TDF_MAX) {
126 			ret = -EINVAL;
127 			goto out;
128 		}
129 
130 		if (ncycles < ATMEL_SMC_MODE_TDF_MIN)
131 			ncycles = ATMEL_SMC_MODE_TDF_MIN;
132 
133 		smcconf->mode |= ATMEL_SMC_MODE_TDF(ncycles);
134 	}
135 
136 	for (i = 0; i < ARRAY_SIZE(timings_xlate_table); i++) {
137 		const struct atmel_smc_timing_xlate *xlate;
138 
139 		xlate = &timings_xlate_table[i];
140 
141 		ret = of_property_read_u32(np, xlate->name, &val);
142 		if (ret) {
143 			if (!required)
144 				continue;
145 			else
146 				break;
147 		}
148 
149 		if (!required) {
150 			ret = -EINVAL;
151 			break;
152 		}
153 
154 		ncycles = DIV_ROUND_UP(val, clk_period_ns);
155 		ret = xlate->converter(smcconf, xlate->shift, ncycles);
156 		if (ret)
157 			goto out;
158 	}
159 
160 out:
161 	if (ret) {
162 		dev_err(ebid->ebi->dev,
163 			"missing or invalid timings definition in %pOF",
164 			np);
165 		return ret;
166 	}
167 
168 	return required;
169 }
170 
atmel_ebi_xslate_smc_config(struct atmel_ebi_dev * ebid,struct device_node * np,struct atmel_ebi_dev_config * conf)171 static int atmel_ebi_xslate_smc_config(struct atmel_ebi_dev *ebid,
172 				       struct device_node *np,
173 				       struct atmel_ebi_dev_config *conf)
174 {
175 	struct atmel_smc_cs_conf *smcconf = &conf->smcconf;
176 	bool required = false;
177 	const char *tmp_str;
178 	u32 tmp;
179 	int ret;
180 
181 	ret = of_property_read_u32(np, "atmel,smc-bus-width", &tmp);
182 	if (!ret) {
183 		switch (tmp) {
184 		case 8:
185 			smcconf->mode |= ATMEL_SMC_MODE_DBW_8;
186 			break;
187 
188 		case 16:
189 			smcconf->mode |= ATMEL_SMC_MODE_DBW_16;
190 			break;
191 
192 		case 32:
193 			smcconf->mode |= ATMEL_SMC_MODE_DBW_32;
194 			break;
195 
196 		default:
197 			return -EINVAL;
198 		}
199 
200 		required = true;
201 	}
202 
203 	if (of_property_read_bool(np, "atmel,smc-tdf-optimized")) {
204 		smcconf->mode |= ATMEL_SMC_MODE_TDFMODE_OPTIMIZED;
205 		required = true;
206 	}
207 
208 	tmp_str = NULL;
209 	of_property_read_string(np, "atmel,smc-byte-access-type", &tmp_str);
210 	if (tmp_str && !strcmp(tmp_str, "write")) {
211 		smcconf->mode |= ATMEL_SMC_MODE_BAT_WRITE;
212 		required = true;
213 	}
214 
215 	tmp_str = NULL;
216 	of_property_read_string(np, "atmel,smc-read-mode", &tmp_str);
217 	if (tmp_str && !strcmp(tmp_str, "nrd")) {
218 		smcconf->mode |= ATMEL_SMC_MODE_READMODE_NRD;
219 		required = true;
220 	}
221 
222 	tmp_str = NULL;
223 	of_property_read_string(np, "atmel,smc-write-mode", &tmp_str);
224 	if (tmp_str && !strcmp(tmp_str, "nwe")) {
225 		smcconf->mode |= ATMEL_SMC_MODE_WRITEMODE_NWE;
226 		required = true;
227 	}
228 
229 	tmp_str = NULL;
230 	of_property_read_string(np, "atmel,smc-exnw-mode", &tmp_str);
231 	if (tmp_str) {
232 		if (!strcmp(tmp_str, "frozen"))
233 			smcconf->mode |= ATMEL_SMC_MODE_EXNWMODE_FROZEN;
234 		else if (!strcmp(tmp_str, "ready"))
235 			smcconf->mode |= ATMEL_SMC_MODE_EXNWMODE_READY;
236 		else if (strcmp(tmp_str, "disabled"))
237 			return -EINVAL;
238 
239 		required = true;
240 	}
241 
242 	ret = of_property_read_u32(np, "atmel,smc-page-mode", &tmp);
243 	if (!ret) {
244 		switch (tmp) {
245 		case 4:
246 			smcconf->mode |= ATMEL_SMC_MODE_PS_4;
247 			break;
248 
249 		case 8:
250 			smcconf->mode |= ATMEL_SMC_MODE_PS_8;
251 			break;
252 
253 		case 16:
254 			smcconf->mode |= ATMEL_SMC_MODE_PS_16;
255 			break;
256 
257 		case 32:
258 			smcconf->mode |= ATMEL_SMC_MODE_PS_32;
259 			break;
260 
261 		default:
262 			return -EINVAL;
263 		}
264 
265 		smcconf->mode |= ATMEL_SMC_MODE_PMEN;
266 		required = true;
267 	}
268 
269 	ret = atmel_ebi_xslate_smc_timings(ebid, np, &conf->smcconf);
270 	if (ret < 0)
271 		return -EINVAL;
272 
273 	if ((ret > 0 && !required) || (!ret && required)) {
274 		dev_err(ebid->ebi->dev, "missing atmel,smc- properties in %pOF",
275 			np);
276 		return -EINVAL;
277 	}
278 
279 	return required;
280 }
281 
at91sam9_ebi_apply_config(struct atmel_ebi_dev * ebid,struct atmel_ebi_dev_config * conf)282 static void at91sam9_ebi_apply_config(struct atmel_ebi_dev *ebid,
283 				      struct atmel_ebi_dev_config *conf)
284 {
285 	atmel_smc_cs_conf_apply(ebid->ebi->smc.regmap, conf->cs,
286 				&conf->smcconf);
287 }
288 
sama5_ebi_apply_config(struct atmel_ebi_dev * ebid,struct atmel_ebi_dev_config * conf)289 static void sama5_ebi_apply_config(struct atmel_ebi_dev *ebid,
290 				   struct atmel_ebi_dev_config *conf)
291 {
292 	atmel_hsmc_cs_conf_apply(ebid->ebi->smc.regmap, ebid->ebi->smc.layout,
293 				 conf->cs, &conf->smcconf);
294 }
295 
atmel_ebi_dev_setup(struct atmel_ebi * ebi,struct device_node * np,int reg_cells)296 static int atmel_ebi_dev_setup(struct atmel_ebi *ebi, struct device_node *np,
297 			       int reg_cells)
298 {
299 	const struct atmel_ebi_caps *caps = ebi->caps;
300 	struct atmel_ebi_dev_config conf = { };
301 	struct device *dev = ebi->dev;
302 	struct atmel_ebi_dev *ebid;
303 	unsigned long cslines = 0;
304 	int ret, numcs = 0, nentries, i;
305 	bool apply = false;
306 	u32 cs;
307 
308 	nentries = of_property_count_elems_of_size(np, "reg",
309 						   reg_cells * sizeof(u32));
310 	for (i = 0; i < nentries; i++) {
311 		ret = of_property_read_u32_index(np, "reg", i * reg_cells,
312 						 &cs);
313 		if (ret)
314 			return ret;
315 
316 		if (cs >= AT91_EBI_NUM_CS ||
317 		    !(ebi->caps->available_cs & BIT(cs))) {
318 			dev_err(dev, "invalid reg property in %pOF\n", np);
319 			return -EINVAL;
320 		}
321 
322 		if (!test_and_set_bit(cs, &cslines))
323 			numcs++;
324 	}
325 
326 	if (!numcs) {
327 		dev_err(dev, "invalid reg property in %pOF\n", np);
328 		return -EINVAL;
329 	}
330 
331 	ebid = devm_kzalloc(ebi->dev, struct_size(ebid, configs, numcs),
332 			    GFP_KERNEL);
333 	if (!ebid)
334 		return -ENOMEM;
335 
336 	ebid->ebi = ebi;
337 	ebid->numcs = numcs;
338 
339 	ret = caps->xlate_config(ebid, np, &conf);
340 	if (ret < 0)
341 		return ret;
342 	else if (ret)
343 		apply = true;
344 
345 	i = 0;
346 	for_each_set_bit(cs, &cslines, AT91_EBI_NUM_CS) {
347 		ebid->configs[i].cs = cs;
348 
349 		if (apply) {
350 			conf.cs = cs;
351 			caps->apply_config(ebid, &conf);
352 		}
353 
354 		caps->get_config(ebid, &ebid->configs[i]);
355 
356 		/*
357 		 * Attach the EBI device to the generic SMC logic if at least
358 		 * one "atmel,smc-" property is present.
359 		 */
360 		if (ebi->caps->ebi_csa_offs && apply)
361 			regmap_update_bits(ebi->regmap,
362 					   ebi->caps->ebi_csa_offs,
363 					   BIT(cs), 0);
364 
365 		i++;
366 	}
367 
368 	list_add_tail(&ebid->node, &ebi->devs);
369 
370 	return 0;
371 }
372 
373 static const struct atmel_ebi_caps at91sam9260_ebi_caps = {
374 	.available_cs = 0xff,
375 	.ebi_csa_offs = AT91SAM9260_MATRIX_EBICSA,
376 	.regmap_name = "atmel,matrix",
377 	.get_config = at91sam9_ebi_get_config,
378 	.xlate_config = atmel_ebi_xslate_smc_config,
379 	.apply_config = at91sam9_ebi_apply_config,
380 };
381 
382 static const struct atmel_ebi_caps at91sam9261_ebi_caps = {
383 	.available_cs = 0xff,
384 	.ebi_csa_offs = AT91SAM9261_MATRIX_EBICSA,
385 	.regmap_name = "atmel,matrix",
386 	.get_config = at91sam9_ebi_get_config,
387 	.xlate_config = atmel_ebi_xslate_smc_config,
388 	.apply_config = at91sam9_ebi_apply_config,
389 };
390 
391 static const struct atmel_ebi_caps at91sam9263_ebi0_caps = {
392 	.available_cs = 0x3f,
393 	.ebi_csa_offs = AT91SAM9263_MATRIX_EBI0CSA,
394 	.regmap_name = "atmel,matrix",
395 	.get_config = at91sam9_ebi_get_config,
396 	.xlate_config = atmel_ebi_xslate_smc_config,
397 	.apply_config = at91sam9_ebi_apply_config,
398 };
399 
400 static const struct atmel_ebi_caps at91sam9263_ebi1_caps = {
401 	.available_cs = 0x7,
402 	.ebi_csa_offs = AT91SAM9263_MATRIX_EBI1CSA,
403 	.regmap_name = "atmel,matrix",
404 	.get_config = at91sam9_ebi_get_config,
405 	.xlate_config = atmel_ebi_xslate_smc_config,
406 	.apply_config = at91sam9_ebi_apply_config,
407 };
408 
409 static const struct atmel_ebi_caps at91sam9rl_ebi_caps = {
410 	.available_cs = 0x3f,
411 	.ebi_csa_offs = AT91SAM9RL_MATRIX_EBICSA,
412 	.regmap_name = "atmel,matrix",
413 	.get_config = at91sam9_ebi_get_config,
414 	.xlate_config = atmel_ebi_xslate_smc_config,
415 	.apply_config = at91sam9_ebi_apply_config,
416 };
417 
418 static const struct atmel_ebi_caps at91sam9g45_ebi_caps = {
419 	.available_cs = 0x3f,
420 	.ebi_csa_offs = AT91SAM9G45_MATRIX_EBICSA,
421 	.regmap_name = "atmel,matrix",
422 	.get_config = at91sam9_ebi_get_config,
423 	.xlate_config = atmel_ebi_xslate_smc_config,
424 	.apply_config = at91sam9_ebi_apply_config,
425 };
426 
427 static const struct atmel_ebi_caps at91sam9x5_ebi_caps = {
428 	.available_cs = 0x3f,
429 	.ebi_csa_offs = AT91SAM9X5_MATRIX_EBICSA,
430 	.regmap_name = "atmel,matrix",
431 	.get_config = at91sam9_ebi_get_config,
432 	.xlate_config = atmel_ebi_xslate_smc_config,
433 	.apply_config = at91sam9_ebi_apply_config,
434 };
435 
436 static const struct atmel_ebi_caps sama5d3_ebi_caps = {
437 	.available_cs = 0xf,
438 	.get_config = sama5_ebi_get_config,
439 	.xlate_config = atmel_ebi_xslate_smc_config,
440 	.apply_config = sama5_ebi_apply_config,
441 };
442 
443 static const struct atmel_ebi_caps sam9x60_ebi_caps = {
444 	.available_cs = 0x3f,
445 	.ebi_csa_offs = AT91_SFR_CCFG_EBICSA,
446 	.regmap_name = "microchip,sfr",
447 	.get_config = at91sam9_ebi_get_config,
448 	.xlate_config = atmel_ebi_xslate_smc_config,
449 	.apply_config = at91sam9_ebi_apply_config,
450 };
451 
452 static const struct of_device_id atmel_ebi_id_table[] = {
453 	{
454 		.compatible = "atmel,at91sam9260-ebi",
455 		.data = &at91sam9260_ebi_caps,
456 	},
457 	{
458 		.compatible = "atmel,at91sam9261-ebi",
459 		.data = &at91sam9261_ebi_caps,
460 	},
461 	{
462 		.compatible = "atmel,at91sam9263-ebi0",
463 		.data = &at91sam9263_ebi0_caps,
464 	},
465 	{
466 		.compatible = "atmel,at91sam9263-ebi1",
467 		.data = &at91sam9263_ebi1_caps,
468 	},
469 	{
470 		.compatible = "atmel,at91sam9rl-ebi",
471 		.data = &at91sam9rl_ebi_caps,
472 	},
473 	{
474 		.compatible = "atmel,at91sam9g45-ebi",
475 		.data = &at91sam9g45_ebi_caps,
476 	},
477 	{
478 		.compatible = "atmel,at91sam9x5-ebi",
479 		.data = &at91sam9x5_ebi_caps,
480 	},
481 	{
482 		.compatible = "atmel,sama5d3-ebi",
483 		.data = &sama5d3_ebi_caps,
484 	},
485 	{
486 		.compatible = "microchip,sam9x60-ebi",
487 		.data = &sam9x60_ebi_caps,
488 	},
489 	{ /* sentinel */ }
490 };
491 
atmel_ebi_dev_disable(struct atmel_ebi * ebi,struct device_node * np)492 static int atmel_ebi_dev_disable(struct atmel_ebi *ebi, struct device_node *np)
493 {
494 	struct device *dev = ebi->dev;
495 	struct property *newprop;
496 
497 	newprop = devm_kzalloc(dev, sizeof(*newprop), GFP_KERNEL);
498 	if (!newprop)
499 		return -ENOMEM;
500 
501 	newprop->name = devm_kstrdup(dev, "status", GFP_KERNEL);
502 	if (!newprop->name)
503 		return -ENOMEM;
504 
505 	newprop->value = devm_kstrdup(dev, "disabled", GFP_KERNEL);
506 	if (!newprop->value)
507 		return -ENOMEM;
508 
509 	newprop->length = sizeof("disabled");
510 
511 	return of_update_property(np, newprop);
512 }
513 
atmel_ebi_probe(struct platform_device * pdev)514 static int atmel_ebi_probe(struct platform_device *pdev)
515 {
516 	struct device *dev = &pdev->dev;
517 	struct device_node *child, *np = dev->of_node, *smc_np;
518 	const struct of_device_id *match;
519 	struct atmel_ebi *ebi;
520 	int ret, reg_cells;
521 	struct clk *clk;
522 	u32 val;
523 
524 	match = of_match_device(atmel_ebi_id_table, dev);
525 	if (!match || !match->data)
526 		return -EINVAL;
527 
528 	ebi = devm_kzalloc(dev, sizeof(*ebi), GFP_KERNEL);
529 	if (!ebi)
530 		return -ENOMEM;
531 
532 	platform_set_drvdata(pdev, ebi);
533 
534 	INIT_LIST_HEAD(&ebi->devs);
535 	ebi->caps = match->data;
536 	ebi->dev = dev;
537 
538 	clk = devm_clk_get(dev, NULL);
539 	if (IS_ERR(clk))
540 		return PTR_ERR(clk);
541 
542 	ebi->clk = clk;
543 
544 	smc_np = of_parse_phandle(dev->of_node, "atmel,smc", 0);
545 
546 	ebi->smc.regmap = syscon_node_to_regmap(smc_np);
547 	if (IS_ERR(ebi->smc.regmap)) {
548 		ret = PTR_ERR(ebi->smc.regmap);
549 		goto put_node;
550 	}
551 
552 	ebi->smc.layout = atmel_hsmc_get_reg_layout(smc_np);
553 	if (IS_ERR(ebi->smc.layout)) {
554 		ret = PTR_ERR(ebi->smc.layout);
555 		goto put_node;
556 	}
557 
558 	ebi->smc.clk = of_clk_get(smc_np, 0);
559 	if (IS_ERR(ebi->smc.clk)) {
560 		if (PTR_ERR(ebi->smc.clk) != -ENOENT) {
561 			ret = PTR_ERR(ebi->smc.clk);
562 			goto put_node;
563 		}
564 
565 		ebi->smc.clk = NULL;
566 	}
567 	of_node_put(smc_np);
568 	ret = clk_prepare_enable(ebi->smc.clk);
569 	if (ret)
570 		return ret;
571 
572 	/*
573 	 * The sama5d3 does not provide an EBICSA register and thus does need
574 	 * to access it.
575 	 */
576 	if (ebi->caps->ebi_csa_offs) {
577 		ebi->regmap =
578 			syscon_regmap_lookup_by_phandle(np,
579 							ebi->caps->regmap_name);
580 		if (IS_ERR(ebi->regmap))
581 			return PTR_ERR(ebi->regmap);
582 	}
583 
584 	ret = of_property_read_u32(np, "#address-cells", &val);
585 	if (ret) {
586 		dev_err(dev, "missing #address-cells property\n");
587 		return ret;
588 	}
589 
590 	reg_cells = val;
591 
592 	ret = of_property_read_u32(np, "#size-cells", &val);
593 	if (ret) {
594 		dev_err(dev, "missing #address-cells property\n");
595 		return ret;
596 	}
597 
598 	reg_cells += val;
599 
600 	for_each_available_child_of_node(np, child) {
601 		if (!of_property_present(child, "reg"))
602 			continue;
603 
604 		ret = atmel_ebi_dev_setup(ebi, child, reg_cells);
605 		if (ret) {
606 			dev_err(dev, "failed to configure EBI bus for %pOF, disabling the device",
607 				child);
608 
609 			ret = atmel_ebi_dev_disable(ebi, child);
610 			if (ret) {
611 				of_node_put(child);
612 				return ret;
613 			}
614 		}
615 	}
616 
617 	return of_platform_populate(np, NULL, NULL, dev);
618 
619 put_node:
620 	of_node_put(smc_np);
621 	return ret;
622 }
623 
atmel_ebi_resume(struct device * dev)624 static __maybe_unused int atmel_ebi_resume(struct device *dev)
625 {
626 	struct atmel_ebi *ebi = dev_get_drvdata(dev);
627 	struct atmel_ebi_dev *ebid;
628 
629 	list_for_each_entry(ebid, &ebi->devs, node) {
630 		int i;
631 
632 		for (i = 0; i < ebid->numcs; i++)
633 			ebid->ebi->caps->apply_config(ebid, &ebid->configs[i]);
634 	}
635 
636 	return 0;
637 }
638 
639 static SIMPLE_DEV_PM_OPS(atmel_ebi_pm_ops, NULL, atmel_ebi_resume);
640 
641 static struct platform_driver atmel_ebi_driver = {
642 	.driver = {
643 		.name = "atmel-ebi",
644 		.of_match_table	= atmel_ebi_id_table,
645 		.pm = &atmel_ebi_pm_ops,
646 	},
647 };
648 builtin_platform_driver_probe(atmel_ebi_driver, atmel_ebi_probe);
649