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/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/device.h>
17 #include <linux/slab.h>
18 #include <linux/debugfs.h>
19 #include <linux/seq_file.h>
20 #include <linux/pinctrl/pinctrl.h>
21 #include <linux/pinctrl/pinconf.h>
22 #include <linux/pinctrl/pinconf-generic.h>
23 #include <linux/of.h>
24 #include "core.h"
25 #include "pinconf.h"
26 #include "pinctrl-utils.h"
27 
28 #ifdef CONFIG_DEBUG_FS
29 static const struct pin_config_item conf_items[] = {
30 	PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
31 	PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
32 	PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
33 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", "ohms", true),
34 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
35 				"input bias pull to pin specific state", "ohms", true),
36 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", "ohms", true),
37 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
38 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
39 	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
40 	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
41 	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),
42 	PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
43 	PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
44 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
45 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
46 	PCONFDUMP(PIN_CONFIG_MODE_LOW_POWER, "pin low power", "mode", true),
47 	PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
48 	PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
49 	PCONFDUMP(PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, "output impedance", "ohms", true),
50 	PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
51 	PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
52 	PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
53 	PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),
54 };
55 
56 static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
57 				     struct seq_file *s, const char *gname,
58 				     unsigned pin,
59 				     const struct pin_config_item *items,
60 				     int nitems, int *print_sep)
61 {
62 	int i;
63 
64 	for (i = 0; i < nitems; i++) {
65 		unsigned long config;
66 		int ret;
67 
68 		/* We want to check out this parameter */
69 		config = pinconf_to_config_packed(items[i].param, 0);
70 		if (gname)
71 			ret = pin_config_group_get(dev_name(pctldev->dev),
72 						   gname, &config);
73 		else
74 			ret = pin_config_get_for_pin(pctldev, pin, &config);
75 		/* These are legal errors */
76 		if (ret == -EINVAL || ret == -ENOTSUPP)
77 			continue;
78 		if (ret) {
79 			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
80 			continue;
81 		}
82 		/* comma between multiple configs */
83 		if (*print_sep)
84 			seq_puts(s, ", ");
85 		*print_sep = 1;
86 		seq_puts(s, items[i].display);
87 		/* Print unit if available */
88 		if (items[i].has_arg) {
89 			seq_printf(s, " (%u",
90 				   pinconf_to_config_argument(config));
91 			if (items[i].format)
92 				seq_printf(s, " %s)", items[i].format);
93 			else
94 				seq_puts(s, ")");
95 		}
96 	}
97 }
98 
99 /**
100  * pinconf_generic_dump_pins - Print information about pin or group of pins
101  * @pctldev:	Pincontrol device
102  * @s:		File to print to
103  * @gname:	Group name specifying pins
104  * @pin:	Pin number specyfying pin
105  *
106  * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
107  * specified either by pin using @pin or by group using @gname. Only one needs
108  * to be specified the other can be NULL/0.
109  */
110 void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
111 			       const char *gname, unsigned pin)
112 {
113 	const struct pinconf_ops *ops = pctldev->desc->confops;
114 	int print_sep = 0;
115 
116 	if (!ops->is_generic)
117 		return;
118 
119 	/* generic parameters */
120 	pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
121 				 ARRAY_SIZE(conf_items), &print_sep);
122 	/* driver-specific parameters */
123 	if (pctldev->desc->num_custom_params &&
124 	    pctldev->desc->custom_conf_items)
125 		pinconf_generic_dump_one(pctldev, s, gname, pin,
126 					 pctldev->desc->custom_conf_items,
127 					 pctldev->desc->num_custom_params,
128 					 &print_sep);
129 }
130 
131 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
132 				 struct seq_file *s, unsigned long config)
133 {
134 	int i;
135 
136 	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
137 		if (pinconf_to_config_param(config) != conf_items[i].param)
138 			continue;
139 		seq_printf(s, "%s: 0x%x", conf_items[i].display,
140 			   pinconf_to_config_argument(config));
141 	}
142 
143 	if (!pctldev->desc->num_custom_params ||
144 	    !pctldev->desc->custom_conf_items)
145 		return;
146 
147 	for (i = 0; i < pctldev->desc->num_custom_params; i++) {
148 		if (pinconf_to_config_param(config) !=
149 		    pctldev->desc->custom_conf_items[i].param)
150 			continue;
151 		seq_printf(s, "%s: 0x%x",
152 				pctldev->desc->custom_conf_items[i].display,
153 				pinconf_to_config_argument(config));
154 	}
155 }
156 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
157 #endif
158 
159 #ifdef CONFIG_OF
160 static const struct pinconf_generic_params dt_params[] = {
161 	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
162 	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
163 	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
164 	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
165 	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
166 	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
167 	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
168 	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
169 	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
170 	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
171 	{ "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },
172 	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
173 	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
174 	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
175 	{ "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
176 	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
177 	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
178 	{ "low-power-disable", PIN_CONFIG_MODE_LOW_POWER, 0 },
179 	{ "low-power-enable", PIN_CONFIG_MODE_LOW_POWER, 1 },
180 	{ "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
181 	{ "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
182 	{ "output-high", PIN_CONFIG_OUTPUT, 1, },
183 	{ "output-impedance-ohms", PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, 0 },
184 	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
185 	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
186 	{ "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
187 	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
188 	{ "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
189 };
190 
191 /**
192  * parse_dt_cfg() - Parse DT pinconf parameters
193  * @np:	DT node
194  * @params:	Array of describing generic parameters
195  * @count:	Number of entries in @params
196  * @cfg:	Array of parsed config options
197  * @ncfg:	Number of entries in @cfg
198  *
199  * Parse the config options described in @params from @np and puts the result
200  * in @cfg. @cfg does not need to be empty, entries are added beginning at
201  * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
202  * needs to have enough memory allocated to hold all possible entries.
203  */
204 static void parse_dt_cfg(struct device_node *np,
205 			 const struct pinconf_generic_params *params,
206 			 unsigned int count, unsigned long *cfg,
207 			 unsigned int *ncfg)
208 {
209 	int i;
210 
211 	for (i = 0; i < count; i++) {
212 		u32 val;
213 		int ret;
214 		const struct pinconf_generic_params *par = &params[i];
215 
216 		ret = of_property_read_u32(np, par->property, &val);
217 
218 		/* property not found */
219 		if (ret == -EINVAL)
220 			continue;
221 
222 		/* use default value, when no value is specified */
223 		if (ret)
224 			val = par->default_value;
225 
226 		pr_debug("found %s with value %u\n", par->property, val);
227 		cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
228 		(*ncfg)++;
229 	}
230 }
231 
232 /**
233  * pinconf_generic_parse_dt_config()
234  * parse the config properties into generic pinconfig values.
235  * @np: node containing the pinconfig properties
236  * @pctldev: pincontrol device
237  * @configs: array with nconfigs entries containing the generic pinconf values
238  *           must be freed when no longer necessary.
239  * @nconfigs: number of configurations
240  */
241 int pinconf_generic_parse_dt_config(struct device_node *np,
242 				    struct pinctrl_dev *pctldev,
243 				    unsigned long **configs,
244 				    unsigned int *nconfigs)
245 {
246 	unsigned long *cfg;
247 	unsigned int max_cfg, ncfg = 0;
248 	int ret;
249 
250 	if (!np)
251 		return -EINVAL;
252 
253 	/* allocate a temporary array big enough to hold one of each option */
254 	max_cfg = ARRAY_SIZE(dt_params);
255 	if (pctldev)
256 		max_cfg += pctldev->desc->num_custom_params;
257 	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
258 	if (!cfg)
259 		return -ENOMEM;
260 
261 	parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
262 	if (pctldev && pctldev->desc->num_custom_params &&
263 		pctldev->desc->custom_params)
264 		parse_dt_cfg(np, pctldev->desc->custom_params,
265 			     pctldev->desc->num_custom_params, cfg, &ncfg);
266 
267 	ret = 0;
268 
269 	/* no configs found at all */
270 	if (ncfg == 0) {
271 		*configs = NULL;
272 		*nconfigs = 0;
273 		goto out;
274 	}
275 
276 	/*
277 	 * Now limit the number of configs to the real number of
278 	 * found properties.
279 	 */
280 	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
281 	if (!*configs) {
282 		ret = -ENOMEM;
283 		goto out;
284 	}
285 
286 	*nconfigs = ncfg;
287 
288 out:
289 	kfree(cfg);
290 	return ret;
291 }
292 EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);
293 
294 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
295 		struct device_node *np, struct pinctrl_map **map,
296 		unsigned *reserved_maps, unsigned *num_maps,
297 		enum pinctrl_map_type type)
298 {
299 	int ret;
300 	const char *function;
301 	struct device *dev = pctldev->dev;
302 	unsigned long *configs = NULL;
303 	unsigned num_configs = 0;
304 	unsigned reserve, strings_count;
305 	struct property *prop;
306 	const char *group;
307 	const char *subnode_target_type = "pins";
308 
309 	ret = of_property_count_strings(np, "pins");
310 	if (ret < 0) {
311 		ret = of_property_count_strings(np, "groups");
312 		if (ret < 0)
313 			/* skip this node; may contain config child nodes */
314 			return 0;
315 		if (type == PIN_MAP_TYPE_INVALID)
316 			type = PIN_MAP_TYPE_CONFIGS_GROUP;
317 		subnode_target_type = "groups";
318 	} else {
319 		if (type == PIN_MAP_TYPE_INVALID)
320 			type = PIN_MAP_TYPE_CONFIGS_PIN;
321 	}
322 	strings_count = ret;
323 
324 	ret = of_property_read_string(np, "function", &function);
325 	if (ret < 0) {
326 		/* EINVAL=missing, which is fine since it's optional */
327 		if (ret != -EINVAL)
328 			dev_err(dev, "%pOF: could not parse property function\n",
329 				np);
330 		function = NULL;
331 	}
332 
333 	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
334 					      &num_configs);
335 	if (ret < 0) {
336 		dev_err(dev, "%pOF: could not parse node property\n", np);
337 		return ret;
338 	}
339 
340 	reserve = 0;
341 	if (function != NULL)
342 		reserve++;
343 	if (num_configs)
344 		reserve++;
345 
346 	reserve *= strings_count;
347 
348 	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
349 			num_maps, reserve);
350 	if (ret < 0)
351 		goto exit;
352 
353 	of_property_for_each_string(np, subnode_target_type, prop, group) {
354 		if (function) {
355 			ret = pinctrl_utils_add_map_mux(pctldev, map,
356 					reserved_maps, num_maps, group,
357 					function);
358 			if (ret < 0)
359 				goto exit;
360 		}
361 
362 		if (num_configs) {
363 			ret = pinctrl_utils_add_map_configs(pctldev, map,
364 					reserved_maps, num_maps, group, configs,
365 					num_configs, type);
366 			if (ret < 0)
367 				goto exit;
368 		}
369 	}
370 	ret = 0;
371 
372 exit:
373 	kfree(configs);
374 	return ret;
375 }
376 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
377 
378 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
379 		struct device_node *np_config, struct pinctrl_map **map,
380 		unsigned *num_maps, enum pinctrl_map_type type)
381 {
382 	unsigned reserved_maps;
383 	struct device_node *np;
384 	int ret;
385 
386 	reserved_maps = 0;
387 	*map = NULL;
388 	*num_maps = 0;
389 
390 	ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
391 						&reserved_maps, num_maps, type);
392 	if (ret < 0)
393 		goto exit;
394 
395 	for_each_available_child_of_node(np_config, np) {
396 		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
397 					&reserved_maps, num_maps, type);
398 		if (ret < 0) {
399 			of_node_put(np);
400 			goto exit;
401 		}
402 	}
403 	return 0;
404 
405 exit:
406 	pinctrl_utils_free_map(pctldev, *map, *num_maps);
407 	return ret;
408 }
409 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
410 
411 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
412 				 struct pinctrl_map *map,
413 				 unsigned num_maps)
414 {
415 	pinctrl_utils_free_map(pctldev, map, num_maps);
416 }
417 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
418 
419 #endif
420