xref: /openbmc/linux/drivers/memory/atmel-ebi.c (revision feac8c8b)
1 /*
2  * EBI driver for Atmel chips
3  * inspired by the fsl weim bus driver
4  *
5  * Copyright (C) 2013 Jean-Jacques Hiblot <jjhiblot@traphandler.com>
6  *
7  * This file is licensed under the terms of the GNU General Public
8  * License version 2. This program is licensed "as is" without any
9  * warranty of any kind, whether express or implied.
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/io.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/mfd/syscon/atmel-matrix.h>
16 #include <linux/mfd/syscon/atmel-smc.h>
17 #include <linux/init.h>
18 #include <linux/of_device.h>
19 #include <linux/regmap.h>
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 	void (*get_config)(struct atmel_ebi_dev *ebid,
40 			   struct atmel_ebi_dev_config *conf);
41 	int (*xlate_config)(struct atmel_ebi_dev *ebid,
42 			    struct device_node *configs_np,
43 			    struct atmel_ebi_dev_config *conf);
44 	void (*apply_config)(struct atmel_ebi_dev *ebid,
45 			     struct atmel_ebi_dev_config *conf);
46 };
47 
48 struct atmel_ebi {
49 	struct clk *clk;
50 	struct regmap *matrix;
51 	struct  {
52 		struct regmap *regmap;
53 		struct clk *clk;
54 		const struct atmel_hsmc_reg_layout *layout;
55 	} smc;
56 
57 	struct device *dev;
58 	const struct atmel_ebi_caps *caps;
59 	struct list_head devs;
60 };
61 
62 struct atmel_smc_timing_xlate {
63 	const char *name;
64 	int (*converter)(struct atmel_smc_cs_conf *conf,
65 			 unsigned int shift, unsigned int nycles);
66 	unsigned int shift;
67 };
68 
69 #define ATMEL_SMC_SETUP_XLATE(nm, pos)	\
70 	{ .name = nm, .converter = atmel_smc_cs_conf_set_setup, .shift = pos}
71 
72 #define ATMEL_SMC_PULSE_XLATE(nm, pos)	\
73 	{ .name = nm, .converter = atmel_smc_cs_conf_set_pulse, .shift = pos}
74 
75 #define ATMEL_SMC_CYCLE_XLATE(nm, pos)	\
76 	{ .name = nm, .converter = atmel_smc_cs_conf_set_cycle, .shift = pos}
77 
78 static void at91sam9_ebi_get_config(struct atmel_ebi_dev *ebid,
79 				    struct atmel_ebi_dev_config *conf)
80 {
81 	atmel_smc_cs_conf_get(ebid->ebi->smc.regmap, conf->cs,
82 			      &conf->smcconf);
83 }
84 
85 static void sama5_ebi_get_config(struct atmel_ebi_dev *ebid,
86 				 struct atmel_ebi_dev_config *conf)
87 {
88 	atmel_hsmc_cs_conf_get(ebid->ebi->smc.regmap, ebid->ebi->smc.layout,
89 			       conf->cs, &conf->smcconf);
90 }
91 
92 static const struct atmel_smc_timing_xlate timings_xlate_table[] = {
93 	ATMEL_SMC_SETUP_XLATE("atmel,smc-ncs-rd-setup-ns",
94 			      ATMEL_SMC_NCS_RD_SHIFT),
95 	ATMEL_SMC_SETUP_XLATE("atmel,smc-ncs-wr-setup-ns",
96 			      ATMEL_SMC_NCS_WR_SHIFT),
97 	ATMEL_SMC_SETUP_XLATE("atmel,smc-nrd-setup-ns", ATMEL_SMC_NRD_SHIFT),
98 	ATMEL_SMC_SETUP_XLATE("atmel,smc-nwe-setup-ns", ATMEL_SMC_NWE_SHIFT),
99 	ATMEL_SMC_PULSE_XLATE("atmel,smc-ncs-rd-pulse-ns",
100 			      ATMEL_SMC_NCS_RD_SHIFT),
101 	ATMEL_SMC_PULSE_XLATE("atmel,smc-ncs-wr-pulse-ns",
102 			      ATMEL_SMC_NCS_WR_SHIFT),
103 	ATMEL_SMC_PULSE_XLATE("atmel,smc-nrd-pulse-ns", ATMEL_SMC_NRD_SHIFT),
104 	ATMEL_SMC_PULSE_XLATE("atmel,smc-nwe-pulse-ns", ATMEL_SMC_NWE_SHIFT),
105 	ATMEL_SMC_CYCLE_XLATE("atmel,smc-nrd-cycle-ns", ATMEL_SMC_NRD_SHIFT),
106 	ATMEL_SMC_CYCLE_XLATE("atmel,smc-nwe-cycle-ns", ATMEL_SMC_NWE_SHIFT),
107 };
108 
109 static int atmel_ebi_xslate_smc_timings(struct atmel_ebi_dev *ebid,
110 					struct device_node *np,
111 					struct atmel_smc_cs_conf *smcconf)
112 {
113 	unsigned int clk_rate = clk_get_rate(ebid->ebi->clk);
114 	unsigned int clk_period_ns = NSEC_PER_SEC / clk_rate;
115 	bool required = false;
116 	unsigned int ncycles;
117 	int ret, i;
118 	u32 val;
119 
120 	ret = of_property_read_u32(np, "atmel,smc-tdf-ns", &val);
121 	if (!ret) {
122 		required = true;
123 		ncycles = DIV_ROUND_UP(val, clk_period_ns);
124 		if (ncycles > ATMEL_SMC_MODE_TDF_MAX) {
125 			ret = -EINVAL;
126 			goto out;
127 		}
128 
129 		if (ncycles < ATMEL_SMC_MODE_TDF_MIN)
130 			ncycles = ATMEL_SMC_MODE_TDF_MIN;
131 
132 		smcconf->mode |= ATMEL_SMC_MODE_TDF(ncycles);
133 	}
134 
135 	for (i = 0; i < ARRAY_SIZE(timings_xlate_table); i++) {
136 		const struct atmel_smc_timing_xlate *xlate;
137 
138 		xlate = &timings_xlate_table[i];
139 
140 		ret = of_property_read_u32(np, xlate->name, &val);
141 		if (ret) {
142 			if (!required)
143 				continue;
144 			else
145 				break;
146 		}
147 
148 		if (!required) {
149 			ret = -EINVAL;
150 			break;
151 		}
152 
153 		ncycles = DIV_ROUND_UP(val, clk_period_ns);
154 		ret = xlate->converter(smcconf, xlate->shift, ncycles);
155 		if (ret)
156 			goto out;
157 	}
158 
159 out:
160 	if (ret) {
161 		dev_err(ebid->ebi->dev,
162 			"missing or invalid timings definition in %pOF",
163 			np);
164 		return ret;
165 	}
166 
167 	return required;
168 }
169 
170 static int atmel_ebi_xslate_smc_config(struct atmel_ebi_dev *ebid,
171 				       struct device_node *np,
172 				       struct atmel_ebi_dev_config *conf)
173 {
174 	struct atmel_smc_cs_conf *smcconf = &conf->smcconf;
175 	bool required = false;
176 	const char *tmp_str;
177 	u32 tmp;
178 	int ret;
179 
180 	ret = of_property_read_u32(np, "atmel,smc-bus-width", &tmp);
181 	if (!ret) {
182 		switch (tmp) {
183 		case 8:
184 			smcconf->mode |= ATMEL_SMC_MODE_DBW_8;
185 			break;
186 
187 		case 16:
188 			smcconf->mode |= ATMEL_SMC_MODE_DBW_16;
189 			break;
190 
191 		case 32:
192 			smcconf->mode |= ATMEL_SMC_MODE_DBW_32;
193 			break;
194 
195 		default:
196 			return -EINVAL;
197 		}
198 
199 		required = true;
200 	}
201 
202 	if (of_property_read_bool(np, "atmel,smc-tdf-optimized")) {
203 		smcconf->mode |= ATMEL_SMC_MODE_TDFMODE_OPTIMIZED;
204 		required = true;
205 	}
206 
207 	tmp_str = NULL;
208 	of_property_read_string(np, "atmel,smc-byte-access-type", &tmp_str);
209 	if (tmp_str && !strcmp(tmp_str, "write")) {
210 		smcconf->mode |= ATMEL_SMC_MODE_BAT_WRITE;
211 		required = true;
212 	}
213 
214 	tmp_str = NULL;
215 	of_property_read_string(np, "atmel,smc-read-mode", &tmp_str);
216 	if (tmp_str && !strcmp(tmp_str, "nrd")) {
217 		smcconf->mode |= ATMEL_SMC_MODE_READMODE_NRD;
218 		required = true;
219 	}
220 
221 	tmp_str = NULL;
222 	of_property_read_string(np, "atmel,smc-write-mode", &tmp_str);
223 	if (tmp_str && !strcmp(tmp_str, "nwe")) {
224 		smcconf->mode |= ATMEL_SMC_MODE_WRITEMODE_NWE;
225 		required = true;
226 	}
227 
228 	tmp_str = NULL;
229 	of_property_read_string(np, "atmel,smc-exnw-mode", &tmp_str);
230 	if (tmp_str) {
231 		if (!strcmp(tmp_str, "frozen"))
232 			smcconf->mode |= ATMEL_SMC_MODE_EXNWMODE_FROZEN;
233 		else if (!strcmp(tmp_str, "ready"))
234 			smcconf->mode |= ATMEL_SMC_MODE_EXNWMODE_READY;
235 		else if (strcmp(tmp_str, "disabled"))
236 			return -EINVAL;
237 
238 		required = true;
239 	}
240 
241 	ret = of_property_read_u32(np, "atmel,smc-page-mode", &tmp);
242 	if (!ret) {
243 		switch (tmp) {
244 		case 4:
245 			smcconf->mode |= ATMEL_SMC_MODE_PS_4;
246 			break;
247 
248 		case 8:
249 			smcconf->mode |= ATMEL_SMC_MODE_PS_8;
250 			break;
251 
252 		case 16:
253 			smcconf->mode |= ATMEL_SMC_MODE_PS_16;
254 			break;
255 
256 		case 32:
257 			smcconf->mode |= ATMEL_SMC_MODE_PS_32;
258 			break;
259 
260 		default:
261 			return -EINVAL;
262 		}
263 
264 		smcconf->mode |= ATMEL_SMC_MODE_PMEN;
265 		required = true;
266 	}
267 
268 	ret = atmel_ebi_xslate_smc_timings(ebid, np, &conf->smcconf);
269 	if (ret < 0)
270 		return -EINVAL;
271 
272 	if ((ret > 0 && !required) || (!ret && required)) {
273 		dev_err(ebid->ebi->dev, "missing atmel,smc- properties in %pOF",
274 			np);
275 		return -EINVAL;
276 	}
277 
278 	return required;
279 }
280 
281 static void at91sam9_ebi_apply_config(struct atmel_ebi_dev *ebid,
282 				      struct atmel_ebi_dev_config *conf)
283 {
284 	atmel_smc_cs_conf_apply(ebid->ebi->smc.regmap, conf->cs,
285 				&conf->smcconf);
286 }
287 
288 static void sama5_ebi_apply_config(struct atmel_ebi_dev *ebid,
289 				   struct atmel_ebi_dev_config *conf)
290 {
291 	atmel_hsmc_cs_conf_apply(ebid->ebi->smc.regmap, ebid->ebi->smc.layout,
292 				 conf->cs, &conf->smcconf);
293 }
294 
295 static int atmel_ebi_dev_setup(struct atmel_ebi *ebi, struct device_node *np,
296 			       int reg_cells)
297 {
298 	const struct atmel_ebi_caps *caps = ebi->caps;
299 	struct atmel_ebi_dev_config conf = { };
300 	struct device *dev = ebi->dev;
301 	struct atmel_ebi_dev *ebid;
302 	unsigned long cslines = 0;
303 	int ret, numcs = 0, nentries, i;
304 	bool apply = false;
305 	u32 cs;
306 
307 	nentries = of_property_count_elems_of_size(np, "reg",
308 						   reg_cells * sizeof(u32));
309 	for (i = 0; i < nentries; i++) {
310 		ret = of_property_read_u32_index(np, "reg", i * reg_cells,
311 						 &cs);
312 		if (ret)
313 			return ret;
314 
315 		if (cs >= AT91_MATRIX_EBI_NUM_CS ||
316 		    !(ebi->caps->available_cs & BIT(cs))) {
317 			dev_err(dev, "invalid reg property in %pOF\n", np);
318 			return -EINVAL;
319 		}
320 
321 		if (!test_and_set_bit(cs, &cslines))
322 			numcs++;
323 	}
324 
325 	if (!numcs) {
326 		dev_err(dev, "invalid reg property in %pOF\n", np);
327 		return -EINVAL;
328 	}
329 
330 	ebid = devm_kzalloc(ebi->dev,
331 			    sizeof(*ebid) + (numcs * sizeof(*ebid->configs)),
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_MATRIX_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->matrix,
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 	.get_config = at91sam9_ebi_get_config,
377 	.xlate_config = atmel_ebi_xslate_smc_config,
378 	.apply_config = at91sam9_ebi_apply_config,
379 };
380 
381 static const struct atmel_ebi_caps at91sam9261_ebi_caps = {
382 	.available_cs = 0xff,
383 	.ebi_csa_offs = AT91SAM9261_MATRIX_EBICSA,
384 	.get_config = at91sam9_ebi_get_config,
385 	.xlate_config = atmel_ebi_xslate_smc_config,
386 	.apply_config = at91sam9_ebi_apply_config,
387 };
388 
389 static const struct atmel_ebi_caps at91sam9263_ebi0_caps = {
390 	.available_cs = 0x3f,
391 	.ebi_csa_offs = AT91SAM9263_MATRIX_EBI0CSA,
392 	.get_config = at91sam9_ebi_get_config,
393 	.xlate_config = atmel_ebi_xslate_smc_config,
394 	.apply_config = at91sam9_ebi_apply_config,
395 };
396 
397 static const struct atmel_ebi_caps at91sam9263_ebi1_caps = {
398 	.available_cs = 0x7,
399 	.ebi_csa_offs = AT91SAM9263_MATRIX_EBI1CSA,
400 	.get_config = at91sam9_ebi_get_config,
401 	.xlate_config = atmel_ebi_xslate_smc_config,
402 	.apply_config = at91sam9_ebi_apply_config,
403 };
404 
405 static const struct atmel_ebi_caps at91sam9rl_ebi_caps = {
406 	.available_cs = 0x3f,
407 	.ebi_csa_offs = AT91SAM9RL_MATRIX_EBICSA,
408 	.get_config = at91sam9_ebi_get_config,
409 	.xlate_config = atmel_ebi_xslate_smc_config,
410 	.apply_config = at91sam9_ebi_apply_config,
411 };
412 
413 static const struct atmel_ebi_caps at91sam9g45_ebi_caps = {
414 	.available_cs = 0x3f,
415 	.ebi_csa_offs = AT91SAM9G45_MATRIX_EBICSA,
416 	.get_config = at91sam9_ebi_get_config,
417 	.xlate_config = atmel_ebi_xslate_smc_config,
418 	.apply_config = at91sam9_ebi_apply_config,
419 };
420 
421 static const struct atmel_ebi_caps at91sam9x5_ebi_caps = {
422 	.available_cs = 0x3f,
423 	.ebi_csa_offs = AT91SAM9X5_MATRIX_EBICSA,
424 	.get_config = at91sam9_ebi_get_config,
425 	.xlate_config = atmel_ebi_xslate_smc_config,
426 	.apply_config = at91sam9_ebi_apply_config,
427 };
428 
429 static const struct atmel_ebi_caps sama5d3_ebi_caps = {
430 	.available_cs = 0xf,
431 	.get_config = sama5_ebi_get_config,
432 	.xlate_config = atmel_ebi_xslate_smc_config,
433 	.apply_config = sama5_ebi_apply_config,
434 };
435 
436 static const struct of_device_id atmel_ebi_id_table[] = {
437 	{
438 		.compatible = "atmel,at91sam9260-ebi",
439 		.data = &at91sam9260_ebi_caps,
440 	},
441 	{
442 		.compatible = "atmel,at91sam9261-ebi",
443 		.data = &at91sam9261_ebi_caps,
444 	},
445 	{
446 		.compatible = "atmel,at91sam9263-ebi0",
447 		.data = &at91sam9263_ebi0_caps,
448 	},
449 	{
450 		.compatible = "atmel,at91sam9263-ebi1",
451 		.data = &at91sam9263_ebi1_caps,
452 	},
453 	{
454 		.compatible = "atmel,at91sam9rl-ebi",
455 		.data = &at91sam9rl_ebi_caps,
456 	},
457 	{
458 		.compatible = "atmel,at91sam9g45-ebi",
459 		.data = &at91sam9g45_ebi_caps,
460 	},
461 	{
462 		.compatible = "atmel,at91sam9x5-ebi",
463 		.data = &at91sam9x5_ebi_caps,
464 	},
465 	{
466 		.compatible = "atmel,sama5d3-ebi",
467 		.data = &sama5d3_ebi_caps,
468 	},
469 	{ /* sentinel */ }
470 };
471 
472 static int atmel_ebi_dev_disable(struct atmel_ebi *ebi, struct device_node *np)
473 {
474 	struct device *dev = ebi->dev;
475 	struct property *newprop;
476 
477 	newprop = devm_kzalloc(dev, sizeof(*newprop), GFP_KERNEL);
478 	if (!newprop)
479 		return -ENOMEM;
480 
481 	newprop->name = devm_kstrdup(dev, "status", GFP_KERNEL);
482 	if (!newprop->name)
483 		return -ENOMEM;
484 
485 	newprop->value = devm_kstrdup(dev, "disabled", GFP_KERNEL);
486 	if (!newprop->value)
487 		return -ENOMEM;
488 
489 	newprop->length = sizeof("disabled");
490 
491 	return of_update_property(np, newprop);
492 }
493 
494 static int atmel_ebi_probe(struct platform_device *pdev)
495 {
496 	struct device *dev = &pdev->dev;
497 	struct device_node *child, *np = dev->of_node, *smc_np;
498 	const struct of_device_id *match;
499 	struct atmel_ebi *ebi;
500 	int ret, reg_cells;
501 	struct clk *clk;
502 	u32 val;
503 
504 	match = of_match_device(atmel_ebi_id_table, dev);
505 	if (!match || !match->data)
506 		return -EINVAL;
507 
508 	ebi = devm_kzalloc(dev, sizeof(*ebi), GFP_KERNEL);
509 	if (!ebi)
510 		return -ENOMEM;
511 
512 	platform_set_drvdata(pdev, ebi);
513 
514 	INIT_LIST_HEAD(&ebi->devs);
515 	ebi->caps = match->data;
516 	ebi->dev = dev;
517 
518 	clk = devm_clk_get(dev, NULL);
519 	if (IS_ERR(clk))
520 		return PTR_ERR(clk);
521 
522 	ebi->clk = clk;
523 
524 	smc_np = of_parse_phandle(dev->of_node, "atmel,smc", 0);
525 
526 	ebi->smc.regmap = syscon_node_to_regmap(smc_np);
527 	if (IS_ERR(ebi->smc.regmap))
528 		return PTR_ERR(ebi->smc.regmap);
529 
530 	ebi->smc.layout = atmel_hsmc_get_reg_layout(smc_np);
531 	if (IS_ERR(ebi->smc.layout))
532 		return PTR_ERR(ebi->smc.layout);
533 
534 	ebi->smc.clk = of_clk_get(smc_np, 0);
535 	if (IS_ERR(ebi->smc.clk)) {
536 		if (PTR_ERR(ebi->smc.clk) != -ENOENT)
537 			return PTR_ERR(ebi->smc.clk);
538 
539 		ebi->smc.clk = NULL;
540 	}
541 	ret = clk_prepare_enable(ebi->smc.clk);
542 	if (ret)
543 		return ret;
544 
545 	/*
546 	 * The sama5d3 does not provide an EBICSA register and thus does need
547 	 * to access the matrix registers.
548 	 */
549 	if (ebi->caps->ebi_csa_offs) {
550 		ebi->matrix =
551 			syscon_regmap_lookup_by_phandle(np, "atmel,matrix");
552 		if (IS_ERR(ebi->matrix))
553 			return PTR_ERR(ebi->matrix);
554 	}
555 
556 	ret = of_property_read_u32(np, "#address-cells", &val);
557 	if (ret) {
558 		dev_err(dev, "missing #address-cells property\n");
559 		return ret;
560 	}
561 
562 	reg_cells = val;
563 
564 	ret = of_property_read_u32(np, "#size-cells", &val);
565 	if (ret) {
566 		dev_err(dev, "missing #address-cells property\n");
567 		return ret;
568 	}
569 
570 	reg_cells += val;
571 
572 	for_each_available_child_of_node(np, child) {
573 		if (!of_find_property(child, "reg", NULL))
574 			continue;
575 
576 		ret = atmel_ebi_dev_setup(ebi, child, reg_cells);
577 		if (ret) {
578 			dev_err(dev, "failed to configure EBI bus for %pOF, disabling the device",
579 				child);
580 
581 			ret = atmel_ebi_dev_disable(ebi, child);
582 			if (ret)
583 				return ret;
584 		}
585 	}
586 
587 	return of_platform_populate(np, NULL, NULL, dev);
588 }
589 
590 static __maybe_unused int atmel_ebi_resume(struct device *dev)
591 {
592 	struct atmel_ebi *ebi = dev_get_drvdata(dev);
593 	struct atmel_ebi_dev *ebid;
594 
595 	list_for_each_entry(ebid, &ebi->devs, node) {
596 		int i;
597 
598 		for (i = 0; i < ebid->numcs; i++)
599 			ebid->ebi->caps->apply_config(ebid, &ebid->configs[i]);
600 	}
601 
602 	return 0;
603 }
604 
605 static SIMPLE_DEV_PM_OPS(atmel_ebi_pm_ops, NULL, atmel_ebi_resume);
606 
607 static struct platform_driver atmel_ebi_driver = {
608 	.driver = {
609 		.name = "atmel-ebi",
610 		.of_match_table	= atmel_ebi_id_table,
611 		.pm = &atmel_ebi_pm_ops,
612 	},
613 };
614 builtin_platform_driver_probe(atmel_ebi_driver, atmel_ebi_probe);
615