1 /*
2  * Core driver for the imx pin controller in imx1/21/27
3  *
4  * Copyright (C) 2013 Pengutronix
5  * Author: Markus Pargmann <mpa@pengutronix.de>
6  *
7  * Based on pinctrl-imx.c:
8  *	Author: Dong Aisheng <dong.aisheng@linaro.org>
9  *	Copyright (C) 2012 Freescale Semiconductor, Inc.
10  *	Copyright (C) 2012 Linaro Ltd.
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  */
17 
18 #include <linux/bitops.h>
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/io.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include <linux/pinctrl/machine.h>
25 #include <linux/pinctrl/pinconf.h>
26 #include <linux/pinctrl/pinctrl.h>
27 #include <linux/pinctrl/pinmux.h>
28 #include <linux/slab.h>
29 
30 #include "../core.h"
31 #include "pinctrl-imx1.h"
32 
33 struct imx1_pinctrl {
34 	struct device *dev;
35 	struct pinctrl_dev *pctl;
36 	void __iomem *base;
37 	const struct imx1_pinctrl_soc_info *info;
38 };
39 
40 /*
41  * MX1 register offsets
42  */
43 
44 #define MX1_DDIR 0x00
45 #define MX1_OCR 0x04
46 #define MX1_ICONFA 0x0c
47 #define MX1_ICONFB 0x14
48 #define MX1_GIUS 0x20
49 #define MX1_GPR 0x38
50 #define MX1_PUEN 0x40
51 
52 #define MX1_PORT_STRIDE 0x100
53 
54 
55 /*
56  * MUX_ID format defines
57  */
58 #define MX1_MUX_FUNCTION(val) (BIT(0) & val)
59 #define MX1_MUX_GPIO(val) ((BIT(1) & val) >> 1)
60 #define MX1_MUX_DIR(val) ((BIT(2) & val) >> 2)
61 #define MX1_MUX_OCONF(val) (((BIT(4) | BIT(5)) & val) >> 4)
62 #define MX1_MUX_ICONFA(val) (((BIT(8) | BIT(9)) & val) >> 8)
63 #define MX1_MUX_ICONFB(val) (((BIT(10) | BIT(11)) & val) >> 10)
64 
65 
66 /*
67  * IMX1 IOMUXC manages the pins based on ports. Each port has 32 pins. IOMUX
68  * control register are seperated into function, output configuration, input
69  * configuration A, input configuration B, GPIO in use and data direction.
70  *
71  * Those controls that are represented by 1 bit have a direct mapping between
72  * bit position and pin id. If they are represented by 2 bit, the lower 16 pins
73  * are in the first register and the upper 16 pins in the second (next)
74  * register. pin_id is stored in bit (pin_id%16)*2 and the bit above.
75  */
76 
77 /*
78  * Calculates the register offset from a pin_id
79  */
80 static void __iomem *imx1_mem(struct imx1_pinctrl *ipctl, unsigned int pin_id)
81 {
82 	unsigned int port = pin_id / 32;
83 	return ipctl->base + port * MX1_PORT_STRIDE;
84 }
85 
86 /*
87  * Write to a register with 2 bits per pin. The function will automatically
88  * use the next register if the pin is managed in the second register.
89  */
90 static void imx1_write_2bit(struct imx1_pinctrl *ipctl, unsigned int pin_id,
91 		u32 value, u32 reg_offset)
92 {
93 	void __iomem *reg = imx1_mem(ipctl, pin_id) + reg_offset;
94 	int offset = (pin_id % 16) * 2; /* offset, regardless of register used */
95 	int mask = ~(0x3 << offset); /* Mask for 2 bits at offset */
96 	u32 old_val;
97 	u32 new_val;
98 
99 	/* Use the next register if the pin's port pin number is >=16 */
100 	if (pin_id % 32 >= 16)
101 		reg += 0x04;
102 
103 	dev_dbg(ipctl->dev, "write: register 0x%p offset %d value 0x%x\n",
104 			reg, offset, value);
105 
106 	/* Get current state of pins */
107 	old_val = readl(reg);
108 	old_val &= mask;
109 
110 	new_val = value & 0x3; /* Make sure value is really 2 bit */
111 	new_val <<= offset;
112 	new_val |= old_val;/* Set new state for pin_id */
113 
114 	writel(new_val, reg);
115 }
116 
117 static void imx1_write_bit(struct imx1_pinctrl *ipctl, unsigned int pin_id,
118 		u32 value, u32 reg_offset)
119 {
120 	void __iomem *reg = imx1_mem(ipctl, pin_id) + reg_offset;
121 	int offset = pin_id % 32;
122 	int mask = ~BIT_MASK(offset);
123 	u32 old_val;
124 	u32 new_val;
125 
126 	/* Get current state of pins */
127 	old_val = readl(reg);
128 	old_val &= mask;
129 
130 	new_val = value & 0x1; /* Make sure value is really 1 bit */
131 	new_val <<= offset;
132 	new_val |= old_val;/* Set new state for pin_id */
133 
134 	writel(new_val, reg);
135 }
136 
137 static int imx1_read_2bit(struct imx1_pinctrl *ipctl, unsigned int pin_id,
138 		u32 reg_offset)
139 {
140 	void __iomem *reg = imx1_mem(ipctl, pin_id) + reg_offset;
141 	int offset = (pin_id % 16) * 2;
142 
143 	/* Use the next register if the pin's port pin number is >=16 */
144 	if (pin_id % 32 >= 16)
145 		reg += 0x04;
146 
147 	return (readl(reg) & (BIT(offset) | BIT(offset+1))) >> offset;
148 }
149 
150 static int imx1_read_bit(struct imx1_pinctrl *ipctl, unsigned int pin_id,
151 		u32 reg_offset)
152 {
153 	void __iomem *reg = imx1_mem(ipctl, pin_id) + reg_offset;
154 	int offset = pin_id % 32;
155 
156 	return !!(readl(reg) & BIT(offset));
157 }
158 
159 static inline const struct imx1_pin_group *imx1_pinctrl_find_group_by_name(
160 				const struct imx1_pinctrl_soc_info *info,
161 				const char *name)
162 {
163 	const struct imx1_pin_group *grp = NULL;
164 	int i;
165 
166 	for (i = 0; i < info->ngroups; i++) {
167 		if (!strcmp(info->groups[i].name, name)) {
168 			grp = &info->groups[i];
169 			break;
170 		}
171 	}
172 
173 	return grp;
174 }
175 
176 static int imx1_get_groups_count(struct pinctrl_dev *pctldev)
177 {
178 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
179 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
180 
181 	return info->ngroups;
182 }
183 
184 static const char *imx1_get_group_name(struct pinctrl_dev *pctldev,
185 				       unsigned selector)
186 {
187 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
188 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
189 
190 	return info->groups[selector].name;
191 }
192 
193 static int imx1_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
194 			       const unsigned int **pins,
195 			       unsigned *npins)
196 {
197 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
198 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
199 
200 	if (selector >= info->ngroups)
201 		return -EINVAL;
202 
203 	*pins = info->groups[selector].pin_ids;
204 	*npins = info->groups[selector].npins;
205 
206 	return 0;
207 }
208 
209 static void imx1_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
210 		   unsigned offset)
211 {
212 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
213 
214 	seq_printf(s, "GPIO %d, function %d, direction %d, oconf %d, iconfa %d, iconfb %d",
215 			imx1_read_bit(ipctl, offset, MX1_GIUS),
216 			imx1_read_bit(ipctl, offset, MX1_GPR),
217 			imx1_read_bit(ipctl, offset, MX1_DDIR),
218 			imx1_read_2bit(ipctl, offset, MX1_OCR),
219 			imx1_read_2bit(ipctl, offset, MX1_ICONFA),
220 			imx1_read_2bit(ipctl, offset, MX1_ICONFB));
221 }
222 
223 static int imx1_dt_node_to_map(struct pinctrl_dev *pctldev,
224 			struct device_node *np,
225 			struct pinctrl_map **map, unsigned *num_maps)
226 {
227 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
228 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
229 	const struct imx1_pin_group *grp;
230 	struct pinctrl_map *new_map;
231 	struct device_node *parent;
232 	int map_num = 1;
233 	int i, j;
234 
235 	/*
236 	 * first find the group of this node and check if we need create
237 	 * config maps for pins
238 	 */
239 	grp = imx1_pinctrl_find_group_by_name(info, np->name);
240 	if (!grp) {
241 		dev_err(info->dev, "unable to find group for node %s\n",
242 			np->name);
243 		return -EINVAL;
244 	}
245 
246 	for (i = 0; i < grp->npins; i++)
247 		map_num++;
248 
249 	new_map = kmalloc(sizeof(struct pinctrl_map) * map_num, GFP_KERNEL);
250 	if (!new_map)
251 		return -ENOMEM;
252 
253 	*map = new_map;
254 	*num_maps = map_num;
255 
256 	/* create mux map */
257 	parent = of_get_parent(np);
258 	if (!parent) {
259 		kfree(new_map);
260 		return -EINVAL;
261 	}
262 	new_map[0].type = PIN_MAP_TYPE_MUX_GROUP;
263 	new_map[0].data.mux.function = parent->name;
264 	new_map[0].data.mux.group = np->name;
265 	of_node_put(parent);
266 
267 	/* create config map */
268 	new_map++;
269 	for (i = j = 0; i < grp->npins; i++) {
270 		new_map[j].type = PIN_MAP_TYPE_CONFIGS_PIN;
271 		new_map[j].data.configs.group_or_pin =
272 				pin_get_name(pctldev, grp->pins[i].pin_id);
273 		new_map[j].data.configs.configs = &grp->pins[i].config;
274 		new_map[j].data.configs.num_configs = 1;
275 		j++;
276 	}
277 
278 	dev_dbg(pctldev->dev, "maps: function %s group %s num %d\n",
279 		(*map)->data.mux.function, (*map)->data.mux.group, map_num);
280 
281 	return 0;
282 }
283 
284 static void imx1_dt_free_map(struct pinctrl_dev *pctldev,
285 				struct pinctrl_map *map, unsigned num_maps)
286 {
287 	kfree(map);
288 }
289 
290 static const struct pinctrl_ops imx1_pctrl_ops = {
291 	.get_groups_count = imx1_get_groups_count,
292 	.get_group_name = imx1_get_group_name,
293 	.get_group_pins = imx1_get_group_pins,
294 	.pin_dbg_show = imx1_pin_dbg_show,
295 	.dt_node_to_map = imx1_dt_node_to_map,
296 	.dt_free_map = imx1_dt_free_map,
297 
298 };
299 
300 static int imx1_pmx_set(struct pinctrl_dev *pctldev, unsigned selector,
301 			unsigned group)
302 {
303 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
304 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
305 	const struct imx1_pin *pins;
306 	unsigned int npins;
307 	int i;
308 
309 	/*
310 	 * Configure the mux mode for each pin in the group for a specific
311 	 * function.
312 	 */
313 	pins = info->groups[group].pins;
314 	npins = info->groups[group].npins;
315 
316 	WARN_ON(!pins || !npins);
317 
318 	dev_dbg(ipctl->dev, "enable function %s group %s\n",
319 		info->functions[selector].name, info->groups[group].name);
320 
321 	for (i = 0; i < npins; i++) {
322 		unsigned int mux = pins[i].mux_id;
323 		unsigned int pin_id = pins[i].pin_id;
324 		unsigned int afunction = MX1_MUX_FUNCTION(mux);
325 		unsigned int gpio_in_use = MX1_MUX_GPIO(mux);
326 		unsigned int direction = MX1_MUX_DIR(mux);
327 		unsigned int gpio_oconf = MX1_MUX_OCONF(mux);
328 		unsigned int gpio_iconfa = MX1_MUX_ICONFA(mux);
329 		unsigned int gpio_iconfb = MX1_MUX_ICONFB(mux);
330 
331 		dev_dbg(pctldev->dev, "%s, pin 0x%x, function %d, gpio %d, direction %d, oconf %d, iconfa %d, iconfb %d\n",
332 				__func__, pin_id, afunction, gpio_in_use,
333 				direction, gpio_oconf, gpio_iconfa,
334 				gpio_iconfb);
335 
336 		imx1_write_bit(ipctl, pin_id, gpio_in_use, MX1_GIUS);
337 		imx1_write_bit(ipctl, pin_id, direction, MX1_DDIR);
338 
339 		if (gpio_in_use) {
340 			imx1_write_2bit(ipctl, pin_id, gpio_oconf, MX1_OCR);
341 			imx1_write_2bit(ipctl, pin_id, gpio_iconfa,
342 					MX1_ICONFA);
343 			imx1_write_2bit(ipctl, pin_id, gpio_iconfb,
344 					MX1_ICONFB);
345 		} else {
346 			imx1_write_bit(ipctl, pin_id, afunction, MX1_GPR);
347 		}
348 	}
349 
350 	return 0;
351 }
352 
353 static int imx1_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
354 {
355 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
356 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
357 
358 	return info->nfunctions;
359 }
360 
361 static const char *imx1_pmx_get_func_name(struct pinctrl_dev *pctldev,
362 					  unsigned selector)
363 {
364 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
365 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
366 
367 	return info->functions[selector].name;
368 }
369 
370 static int imx1_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
371 			       const char * const **groups,
372 			       unsigned * const num_groups)
373 {
374 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
375 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
376 
377 	*groups = info->functions[selector].groups;
378 	*num_groups = info->functions[selector].num_groups;
379 
380 	return 0;
381 }
382 
383 static const struct pinmux_ops imx1_pmx_ops = {
384 	.get_functions_count = imx1_pmx_get_funcs_count,
385 	.get_function_name = imx1_pmx_get_func_name,
386 	.get_function_groups = imx1_pmx_get_groups,
387 	.set_mux = imx1_pmx_set,
388 };
389 
390 static int imx1_pinconf_get(struct pinctrl_dev *pctldev,
391 			     unsigned pin_id, unsigned long *config)
392 {
393 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
394 
395 	*config = imx1_read_bit(ipctl, pin_id, MX1_PUEN);
396 
397 	return 0;
398 }
399 
400 static int imx1_pinconf_set(struct pinctrl_dev *pctldev,
401 			     unsigned pin_id, unsigned long *configs,
402 			     unsigned num_configs)
403 {
404 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
405 	int i;
406 
407 	for (i = 0; i != num_configs; ++i) {
408 		imx1_write_bit(ipctl, pin_id, configs[i] & 0x01, MX1_PUEN);
409 
410 		dev_dbg(ipctl->dev, "pinconf set pullup pin %s\n",
411 			pin_desc_get(pctldev, pin_id)->name);
412 	}
413 
414 	return 0;
415 }
416 
417 static void imx1_pinconf_dbg_show(struct pinctrl_dev *pctldev,
418 				   struct seq_file *s, unsigned pin_id)
419 {
420 	unsigned long config;
421 
422 	imx1_pinconf_get(pctldev, pin_id, &config);
423 	seq_printf(s, "0x%lx", config);
424 }
425 
426 static void imx1_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
427 					 struct seq_file *s, unsigned group)
428 {
429 	struct imx1_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
430 	const struct imx1_pinctrl_soc_info *info = ipctl->info;
431 	struct imx1_pin_group *grp;
432 	unsigned long config;
433 	const char *name;
434 	int i, ret;
435 
436 	if (group > info->ngroups)
437 		return;
438 
439 	seq_puts(s, "\n");
440 	grp = &info->groups[group];
441 	for (i = 0; i < grp->npins; i++) {
442 		name = pin_get_name(pctldev, grp->pins[i].pin_id);
443 		ret = imx1_pinconf_get(pctldev, grp->pins[i].pin_id, &config);
444 		if (ret)
445 			return;
446 		seq_printf(s, "%s: 0x%lx", name, config);
447 	}
448 }
449 
450 static const struct pinconf_ops imx1_pinconf_ops = {
451 	.pin_config_get = imx1_pinconf_get,
452 	.pin_config_set = imx1_pinconf_set,
453 	.pin_config_dbg_show = imx1_pinconf_dbg_show,
454 	.pin_config_group_dbg_show = imx1_pinconf_group_dbg_show,
455 };
456 
457 static struct pinctrl_desc imx1_pinctrl_desc = {
458 	.pctlops = &imx1_pctrl_ops,
459 	.pmxops = &imx1_pmx_ops,
460 	.confops = &imx1_pinconf_ops,
461 	.owner = THIS_MODULE,
462 };
463 
464 static int imx1_pinctrl_parse_groups(struct device_node *np,
465 				    struct imx1_pin_group *grp,
466 				    struct imx1_pinctrl_soc_info *info,
467 				    u32 index)
468 {
469 	int size;
470 	const __be32 *list;
471 	int i;
472 
473 	dev_dbg(info->dev, "group(%d): %s\n", index, np->name);
474 
475 	/* Initialise group */
476 	grp->name = np->name;
477 
478 	/*
479 	 * the binding format is fsl,pins = <PIN MUX_ID CONFIG>
480 	 */
481 	list = of_get_property(np, "fsl,pins", &size);
482 	/* we do not check return since it's safe node passed down */
483 	if (!size || size % 12) {
484 		dev_notice(info->dev, "Not a valid fsl,pins property (%s)\n",
485 				np->name);
486 		return -EINVAL;
487 	}
488 
489 	grp->npins = size / 12;
490 	grp->pins = devm_kzalloc(info->dev,
491 			grp->npins * sizeof(struct imx1_pin), GFP_KERNEL);
492 	grp->pin_ids = devm_kzalloc(info->dev,
493 			grp->npins * sizeof(unsigned int), GFP_KERNEL);
494 
495 	if (!grp->pins || !grp->pin_ids)
496 		return -ENOMEM;
497 
498 	for (i = 0; i < grp->npins; i++) {
499 		grp->pins[i].pin_id = be32_to_cpu(*list++);
500 		grp->pins[i].mux_id = be32_to_cpu(*list++);
501 		grp->pins[i].config = be32_to_cpu(*list++);
502 
503 		grp->pin_ids[i] = grp->pins[i].pin_id;
504 	}
505 
506 	return 0;
507 }
508 
509 static int imx1_pinctrl_parse_functions(struct device_node *np,
510 				       struct imx1_pinctrl_soc_info *info,
511 				       u32 index)
512 {
513 	struct device_node *child;
514 	struct imx1_pmx_func *func;
515 	struct imx1_pin_group *grp;
516 	int ret;
517 	static u32 grp_index;
518 	u32 i = 0;
519 
520 	dev_dbg(info->dev, "parse function(%d): %s\n", index, np->name);
521 
522 	func = &info->functions[index];
523 
524 	/* Initialise function */
525 	func->name = np->name;
526 	func->num_groups = of_get_child_count(np);
527 	if (func->num_groups == 0)
528 		return -EINVAL;
529 
530 	func->groups = devm_kzalloc(info->dev,
531 			func->num_groups * sizeof(char *), GFP_KERNEL);
532 
533 	if (!func->groups)
534 		return -ENOMEM;
535 
536 	for_each_child_of_node(np, child) {
537 		func->groups[i] = child->name;
538 		grp = &info->groups[grp_index++];
539 		ret = imx1_pinctrl_parse_groups(child, grp, info, i++);
540 		if (ret == -ENOMEM) {
541 			of_node_put(child);
542 			return ret;
543 		}
544 	}
545 
546 	return 0;
547 }
548 
549 static int imx1_pinctrl_parse_dt(struct platform_device *pdev,
550 		struct imx1_pinctrl *pctl, struct imx1_pinctrl_soc_info *info)
551 {
552 	struct device_node *np = pdev->dev.of_node;
553 	struct device_node *child;
554 	int ret;
555 	u32 nfuncs = 0;
556 	u32 ngroups = 0;
557 	u32 ifunc = 0;
558 
559 	if (!np)
560 		return -ENODEV;
561 
562 	for_each_child_of_node(np, child) {
563 		++nfuncs;
564 		ngroups += of_get_child_count(child);
565 	}
566 
567 	if (!nfuncs) {
568 		dev_err(&pdev->dev, "No pin functions defined\n");
569 		return -EINVAL;
570 	}
571 
572 	info->nfunctions = nfuncs;
573 	info->functions = devm_kzalloc(&pdev->dev,
574 			nfuncs * sizeof(struct imx1_pmx_func), GFP_KERNEL);
575 
576 	info->ngroups = ngroups;
577 	info->groups = devm_kzalloc(&pdev->dev,
578 			ngroups * sizeof(struct imx1_pin_group), GFP_KERNEL);
579 
580 
581 	if (!info->functions || !info->groups)
582 		return -ENOMEM;
583 
584 	for_each_child_of_node(np, child) {
585 		ret = imx1_pinctrl_parse_functions(child, info, ifunc++);
586 		if (ret == -ENOMEM) {
587 			of_node_put(child);
588 			return -ENOMEM;
589 		}
590 	}
591 
592 	return 0;
593 }
594 
595 int imx1_pinctrl_core_probe(struct platform_device *pdev,
596 		      struct imx1_pinctrl_soc_info *info)
597 {
598 	struct imx1_pinctrl *ipctl;
599 	struct resource *res;
600 	struct pinctrl_desc *pctl_desc;
601 	int ret;
602 
603 	if (!info || !info->pins || !info->npins) {
604 		dev_err(&pdev->dev, "wrong pinctrl info\n");
605 		return -EINVAL;
606 	}
607 	info->dev = &pdev->dev;
608 
609 	/* Create state holders etc for this driver */
610 	ipctl = devm_kzalloc(&pdev->dev, sizeof(*ipctl), GFP_KERNEL);
611 	if (!ipctl)
612 		return -ENOMEM;
613 
614 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
615 	if (!res)
616 		return -ENOENT;
617 
618 	ipctl->base = devm_ioremap_nocache(&pdev->dev, res->start,
619 			resource_size(res));
620 	if (!ipctl->base)
621 		return -ENOMEM;
622 
623 	pctl_desc = &imx1_pinctrl_desc;
624 	pctl_desc->name = dev_name(&pdev->dev);
625 	pctl_desc->pins = info->pins;
626 	pctl_desc->npins = info->npins;
627 
628 	ret = imx1_pinctrl_parse_dt(pdev, ipctl, info);
629 	if (ret) {
630 		dev_err(&pdev->dev, "fail to probe dt properties\n");
631 		return ret;
632 	}
633 
634 	ipctl->info = info;
635 	ipctl->dev = info->dev;
636 	platform_set_drvdata(pdev, ipctl);
637 	ipctl->pctl = devm_pinctrl_register(&pdev->dev, pctl_desc, ipctl);
638 	if (IS_ERR(ipctl->pctl)) {
639 		dev_err(&pdev->dev, "could not register IMX pinctrl driver\n");
640 		return PTR_ERR(ipctl->pctl);
641 	}
642 
643 	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
644 	if (ret) {
645 		pinctrl_unregister(ipctl->pctl);
646 		dev_err(&pdev->dev, "Failed to populate subdevices\n");
647 		return ret;
648 	}
649 
650 	dev_info(&pdev->dev, "initialized IMX pinctrl driver\n");
651 
652 	return 0;
653 }
654