1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Core driver for the generic pin config portions of the pin control subsystem
4  *
5  * Copyright (C) 2011 ST-Ericsson SA
6  * Written on behalf of Linaro for ST-Ericsson
7  *
8  * Author: Linus Walleij <linus.walleij@linaro.org>
9  */
10 
11 #define pr_fmt(fmt) "generic pinconfig core: " fmt
12 
13 #include <linux/array_size.h>
14 #include <linux/debugfs.h>
15 #include <linux/device.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/slab.h>
20 #include <linux/seq_file.h>
21 
22 #include <linux/pinctrl/pinconf-generic.h>
23 #include <linux/pinctrl/pinconf.h>
24 #include <linux/pinctrl/pinctrl.h>
25 
26 #include "core.h"
27 #include "pinconf.h"
28 #include "pinctrl-utils.h"
29 
30 #ifdef CONFIG_DEBUG_FS
31 static const struct pin_config_item conf_items[] = {
32 	PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
33 	PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
34 	PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
35 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", "ohms", true),
36 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
37 				"input bias pull to pin specific state", "ohms", true),
38 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", "ohms", true),
39 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
40 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
41 	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
42 	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
43 	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),
44 	PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
45 	PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
46 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
47 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_UV, "input schmitt threshold", "uV", true),
48 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
49 	PCONFDUMP(PIN_CONFIG_MODE_LOW_POWER, "pin low power", "mode", true),
50 	PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
51 	PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
52 	PCONFDUMP(PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, "output impedance", "ohms", true),
53 	PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
54 	PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
55 	PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
56 	PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),
57 };
58 
59 static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
60 				     struct seq_file *s, const char *gname,
61 				     unsigned int pin,
62 				     const struct pin_config_item *items,
63 				     int nitems, int *print_sep)
64 {
65 	int i;
66 
67 	for (i = 0; i < nitems; i++) {
68 		unsigned long config;
69 		int ret;
70 
71 		/* We want to check out this parameter */
72 		config = pinconf_to_config_packed(items[i].param, 0);
73 		if (gname)
74 			ret = pin_config_group_get(dev_name(pctldev->dev),
75 						   gname, &config);
76 		else
77 			ret = pin_config_get_for_pin(pctldev, pin, &config);
78 		/* These are legal errors */
79 		if (ret == -EINVAL || ret == -ENOTSUPP)
80 			continue;
81 		if (ret) {
82 			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
83 			continue;
84 		}
85 		/* comma between multiple configs */
86 		if (*print_sep)
87 			seq_puts(s, ", ");
88 		*print_sep = 1;
89 		seq_puts(s, items[i].display);
90 		/* Print unit if available */
91 		if (items[i].has_arg) {
92 			u32 val = pinconf_to_config_argument(config);
93 
94 			if (items[i].format)
95 				seq_printf(s, " (%u %s)", val, items[i].format);
96 			else
97 				seq_printf(s, " (0x%x)", val);
98 		}
99 	}
100 }
101 
102 /**
103  * pinconf_generic_dump_pins - Print information about pin or group of pins
104  * @pctldev:	Pincontrol device
105  * @s:		File to print to
106  * @gname:	Group name specifying pins
107  * @pin:	Pin number specyfying pin
108  *
109  * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
110  * specified either by pin using @pin or by group using @gname. Only one needs
111  * to be specified the other can be NULL/0.
112  */
113 void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
114 			       const char *gname, unsigned int pin)
115 {
116 	const struct pinconf_ops *ops = pctldev->desc->confops;
117 	int print_sep = 0;
118 
119 	if (!ops->is_generic)
120 		return;
121 
122 	/* generic parameters */
123 	pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
124 				 ARRAY_SIZE(conf_items), &print_sep);
125 	/* driver-specific parameters */
126 	if (pctldev->desc->num_custom_params &&
127 	    pctldev->desc->custom_conf_items)
128 		pinconf_generic_dump_one(pctldev, s, gname, pin,
129 					 pctldev->desc->custom_conf_items,
130 					 pctldev->desc->num_custom_params,
131 					 &print_sep);
132 }
133 
134 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
135 				 struct seq_file *s, unsigned long config)
136 {
137 	int i;
138 
139 	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
140 		if (pinconf_to_config_param(config) != conf_items[i].param)
141 			continue;
142 		seq_printf(s, "%s: 0x%x", conf_items[i].display,
143 			   pinconf_to_config_argument(config));
144 	}
145 
146 	if (!pctldev->desc->num_custom_params ||
147 	    !pctldev->desc->custom_conf_items)
148 		return;
149 
150 	for (i = 0; i < pctldev->desc->num_custom_params; i++) {
151 		if (pinconf_to_config_param(config) !=
152 		    pctldev->desc->custom_conf_items[i].param)
153 			continue;
154 		seq_printf(s, "%s: 0x%x",
155 				pctldev->desc->custom_conf_items[i].display,
156 				pinconf_to_config_argument(config));
157 	}
158 }
159 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
160 #endif
161 
162 #ifdef CONFIG_OF
163 static const struct pinconf_generic_params dt_params[] = {
164 	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
165 	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
166 	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
167 	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
168 	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
169 	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
170 	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
171 	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
172 	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
173 	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
174 	{ "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },
175 	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
176 	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
177 	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
178 	{ "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
179 	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
180 	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
181 	{ "input-schmitt-microvolts", PIN_CONFIG_INPUT_SCHMITT_UV, 0 },
182 	{ "low-power-disable", PIN_CONFIG_MODE_LOW_POWER, 0 },
183 	{ "low-power-enable", PIN_CONFIG_MODE_LOW_POWER, 1 },
184 	{ "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
185 	{ "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
186 	{ "output-high", PIN_CONFIG_OUTPUT, 1, },
187 	{ "output-impedance-ohms", PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, 0 },
188 	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
189 	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
190 	{ "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
191 	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
192 	{ "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
193 };
194 
195 /**
196  * parse_dt_cfg() - Parse DT pinconf parameters
197  * @np:	DT node
198  * @params:	Array of describing generic parameters
199  * @count:	Number of entries in @params
200  * @cfg:	Array of parsed config options
201  * @ncfg:	Number of entries in @cfg
202  *
203  * Parse the config options described in @params from @np and puts the result
204  * in @cfg. @cfg does not need to be empty, entries are added beginning at
205  * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
206  * needs to have enough memory allocated to hold all possible entries.
207  */
208 static void parse_dt_cfg(struct device_node *np,
209 			 const struct pinconf_generic_params *params,
210 			 unsigned int count, unsigned long *cfg,
211 			 unsigned int *ncfg)
212 {
213 	int i;
214 
215 	for (i = 0; i < count; i++) {
216 		u32 val;
217 		int ret;
218 		const struct pinconf_generic_params *par = &params[i];
219 
220 		ret = of_property_read_u32(np, par->property, &val);
221 
222 		/* property not found */
223 		if (ret == -EINVAL)
224 			continue;
225 
226 		/* use default value, when no value is specified */
227 		if (ret)
228 			val = par->default_value;
229 
230 		pr_debug("found %s with value %u\n", par->property, val);
231 		cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
232 		(*ncfg)++;
233 	}
234 }
235 
236 /**
237  * pinconf_generic_parse_dt_pinmux()
238  * parse the pinmux properties into generic pin mux values.
239  * @np: node containing the pinmux properties
240  * @dev: pincontrol core device
241  * @pid: array with pin identity entries
242  * @pmux: array with pin mux value entries
243  * @npins: number of pins
244  *
245  * pinmux propertity: mux value [0,7]bits and pin identity [8,31]bits.
246  */
247 int pinconf_generic_parse_dt_pinmux(struct device_node *np, struct device *dev,
248 				    unsigned int **pid, unsigned int **pmux,
249 				    unsigned int *npins)
250 {
251 	unsigned int *pid_t;
252 	unsigned int *pmux_t;
253 	struct property *prop;
254 	unsigned int npins_t, i;
255 	u32 value;
256 	int ret;
257 
258 	prop = of_find_property(np, "pinmux", NULL);
259 	if (!prop) {
260 		dev_info(dev, "Missing pinmux property\n");
261 		return -ENOENT;
262 	}
263 
264 	if (!pid || !pmux || !npins) {
265 		dev_err(dev, "parameters error\n");
266 		return -EINVAL;
267 	}
268 
269 	npins_t = prop->length / sizeof(u32);
270 	pid_t = devm_kcalloc(dev, npins_t, sizeof(*pid_t), GFP_KERNEL);
271 	pmux_t = devm_kcalloc(dev, npins_t, sizeof(*pmux_t), GFP_KERNEL);
272 	if (!pid_t || !pmux_t) {
273 		dev_err(dev, "kalloc memory fail\n");
274 		return -ENOMEM;
275 	}
276 	for (i = 0; i < npins_t; i++) {
277 		ret = of_property_read_u32_index(np, "pinmux", i, &value);
278 		if (ret) {
279 			dev_err(dev, "get pinmux value fail\n");
280 			goto exit;
281 		}
282 		pmux_t[i] = value & 0xff;
283 		pid_t[i] = (value >> 8) & 0xffffff;
284 	}
285 	*pid = pid_t;
286 	*pmux = pmux_t;
287 	*npins = npins_t;
288 
289 	return 0;
290 exit:
291 	devm_kfree(dev, pid_t);
292 	devm_kfree(dev, pmux_t);
293 	return ret;
294 }
295 EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_pinmux);
296 
297 /**
298  * pinconf_generic_parse_dt_config()
299  * parse the config properties into generic pinconfig values.
300  * @np: node containing the pinconfig properties
301  * @pctldev: pincontrol device
302  * @configs: array with nconfigs entries containing the generic pinconf values
303  *           must be freed when no longer necessary.
304  * @nconfigs: number of configurations
305  */
306 int pinconf_generic_parse_dt_config(struct device_node *np,
307 				    struct pinctrl_dev *pctldev,
308 				    unsigned long **configs,
309 				    unsigned int *nconfigs)
310 {
311 	unsigned long *cfg;
312 	unsigned int max_cfg, ncfg = 0;
313 	int ret;
314 
315 	if (!np)
316 		return -EINVAL;
317 
318 	/* allocate a temporary array big enough to hold one of each option */
319 	max_cfg = ARRAY_SIZE(dt_params);
320 	if (pctldev)
321 		max_cfg += pctldev->desc->num_custom_params;
322 	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
323 	if (!cfg)
324 		return -ENOMEM;
325 
326 	parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
327 	if (pctldev && pctldev->desc->num_custom_params &&
328 		pctldev->desc->custom_params)
329 		parse_dt_cfg(np, pctldev->desc->custom_params,
330 			     pctldev->desc->num_custom_params, cfg, &ncfg);
331 
332 	ret = 0;
333 
334 	/* no configs found at all */
335 	if (ncfg == 0) {
336 		*configs = NULL;
337 		*nconfigs = 0;
338 		goto out;
339 	}
340 
341 	/*
342 	 * Now limit the number of configs to the real number of
343 	 * found properties.
344 	 */
345 	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
346 	if (!*configs) {
347 		ret = -ENOMEM;
348 		goto out;
349 	}
350 
351 	*nconfigs = ncfg;
352 
353 out:
354 	kfree(cfg);
355 	return ret;
356 }
357 EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);
358 
359 int pinconf_generic_dt_node_to_map_pinmux(struct pinctrl_dev *pctldev,
360 					  struct device_node *np,
361 					  struct pinctrl_map **map,
362 					  unsigned int *num_maps)
363 {
364 	struct device *dev = pctldev->dev;
365 	struct device_node *pnode;
366 	unsigned long *configs = NULL;
367 	unsigned int num_configs = 0;
368 	struct property *prop;
369 	unsigned int reserved_maps;
370 	int reserve;
371 	int ret;
372 
373 	prop = of_find_property(np, "pinmux", NULL);
374 	if (!prop) {
375 		dev_info(dev, "Missing pinmux property\n");
376 		return -ENOENT;
377 	}
378 
379 	pnode = of_get_parent(np);
380 	if (!pnode) {
381 		dev_info(dev, "Missing function node\n");
382 		return -EINVAL;
383 	}
384 
385 	reserved_maps = 0;
386 	*map = NULL;
387 	*num_maps = 0;
388 
389 	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
390 					      &num_configs);
391 	if (ret < 0) {
392 		dev_err(dev, "%pOF: could not parse node property\n", np);
393 		return ret;
394 	}
395 
396 	reserve = 1;
397 	if (num_configs)
398 		reserve++;
399 
400 	ret = pinctrl_utils_reserve_map(pctldev, map, &reserved_maps,
401 					num_maps, reserve);
402 	if (ret < 0)
403 		goto exit;
404 
405 	ret = pinctrl_utils_add_map_mux(pctldev, map,
406 					&reserved_maps, num_maps, np->name,
407 					pnode->name);
408 	if (ret < 0)
409 		goto exit;
410 
411 	if (num_configs) {
412 		ret = pinctrl_utils_add_map_configs(pctldev, map, &reserved_maps,
413 						    num_maps, np->name, configs,
414 						    num_configs, PIN_MAP_TYPE_CONFIGS_GROUP);
415 		if (ret < 0)
416 			goto exit;
417 	}
418 
419 exit:
420 	kfree(configs);
421 	if (ret)
422 		pinctrl_utils_free_map(pctldev, *map, *num_maps);
423 
424 	return ret;
425 }
426 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map_pinmux);
427 
428 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
429 		struct device_node *np, struct pinctrl_map **map,
430 		unsigned int *reserved_maps, unsigned int *num_maps,
431 		enum pinctrl_map_type type)
432 {
433 	int ret;
434 	const char *function;
435 	struct device *dev = pctldev->dev;
436 	unsigned long *configs = NULL;
437 	unsigned int num_configs = 0;
438 	unsigned int reserve, strings_count;
439 	struct property *prop;
440 	const char *group;
441 	const char *subnode_target_type = "pins";
442 
443 	ret = of_property_count_strings(np, "pins");
444 	if (ret < 0) {
445 		ret = of_property_count_strings(np, "groups");
446 		if (ret < 0)
447 			/* skip this node; may contain config child nodes */
448 			return 0;
449 		if (type == PIN_MAP_TYPE_INVALID)
450 			type = PIN_MAP_TYPE_CONFIGS_GROUP;
451 		subnode_target_type = "groups";
452 	} else {
453 		if (type == PIN_MAP_TYPE_INVALID)
454 			type = PIN_MAP_TYPE_CONFIGS_PIN;
455 	}
456 	strings_count = ret;
457 
458 	ret = of_property_read_string(np, "function", &function);
459 	if (ret < 0) {
460 		/* EINVAL=missing, which is fine since it's optional */
461 		if (ret != -EINVAL)
462 			dev_err(dev, "%pOF: could not parse property function\n",
463 				np);
464 		function = NULL;
465 	}
466 
467 	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
468 					      &num_configs);
469 	if (ret < 0) {
470 		dev_err(dev, "%pOF: could not parse node property\n", np);
471 		return ret;
472 	}
473 
474 	reserve = 0;
475 	if (function != NULL)
476 		reserve++;
477 	if (num_configs)
478 		reserve++;
479 
480 	reserve *= strings_count;
481 
482 	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
483 			num_maps, reserve);
484 	if (ret < 0)
485 		goto exit;
486 
487 	of_property_for_each_string(np, subnode_target_type, prop, group) {
488 		if (function) {
489 			ret = pinctrl_utils_add_map_mux(pctldev, map,
490 					reserved_maps, num_maps, group,
491 					function);
492 			if (ret < 0)
493 				goto exit;
494 		}
495 
496 		if (num_configs) {
497 			ret = pinctrl_utils_add_map_configs(pctldev, map,
498 					reserved_maps, num_maps, group, configs,
499 					num_configs, type);
500 			if (ret < 0)
501 				goto exit;
502 		}
503 	}
504 	ret = 0;
505 
506 exit:
507 	kfree(configs);
508 	return ret;
509 }
510 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
511 
512 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
513 		struct device_node *np_config, struct pinctrl_map **map,
514 		unsigned int *num_maps, enum pinctrl_map_type type)
515 {
516 	unsigned int reserved_maps;
517 	int ret;
518 
519 	reserved_maps = 0;
520 	*map = NULL;
521 	*num_maps = 0;
522 
523 	ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
524 						&reserved_maps, num_maps, type);
525 	if (ret < 0)
526 		goto exit;
527 
528 	for_each_available_child_of_node_scoped(np_config, np) {
529 		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
530 					&reserved_maps, num_maps, type);
531 		if (ret < 0)
532 			goto exit;
533 	}
534 	return 0;
535 
536 exit:
537 	pinctrl_utils_free_map(pctldev, *map, *num_maps);
538 	return ret;
539 }
540 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
541 
542 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
543 				 struct pinctrl_map *map,
544 				 unsigned int num_maps)
545 {
546 	pinctrl_utils_free_map(pctldev, map, num_maps);
547 }
548 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
549 
550 #endif
551