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
31static 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_ENABLE, "input schmitt enabled", NULL, false),
48	PCONFDUMP(PIN_CONFIG_MODE_LOW_POWER, "pin low power", "mode", true),
49	PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
50	PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
51	PCONFDUMP(PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, "output impedance", "ohms", true),
52	PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
53	PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
54	PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
55	PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),
56};
57
58static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
59				     struct seq_file *s, const char *gname,
60				     unsigned int pin,
61				     const struct pin_config_item *items,
62				     int nitems, int *print_sep)
63{
64	int i;
65
66	for (i = 0; i < nitems; i++) {
67		unsigned long config;
68		int ret;
69
70		/* We want to check out this parameter */
71		config = pinconf_to_config_packed(items[i].param, 0);
72		if (gname)
73			ret = pin_config_group_get(dev_name(pctldev->dev),
74						   gname, &config);
75		else
76			ret = pin_config_get_for_pin(pctldev, pin, &config);
77		/* These are legal errors */
78		if (ret == -EINVAL || ret == -ENOTSUPP)
79			continue;
80		if (ret) {
81			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
82			continue;
83		}
84		/* comma between multiple configs */
85		if (*print_sep)
86			seq_puts(s, ", ");
87		*print_sep = 1;
88		seq_puts(s, items[i].display);
89		/* Print unit if available */
90		if (items[i].has_arg) {
91			seq_printf(s, " (%u",
92				   pinconf_to_config_argument(config));
93			if (items[i].format)
94				seq_printf(s, " %s)", items[i].format);
95			else
96				seq_puts(s, ")");
97		}
98	}
99}
100
101/**
102 * pinconf_generic_dump_pins - Print information about pin or group of pins
103 * @pctldev:	Pincontrol device
104 * @s:		File to print to
105 * @gname:	Group name specifying pins
106 * @pin:	Pin number specyfying pin
107 *
108 * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
109 * specified either by pin using @pin or by group using @gname. Only one needs
110 * to be specified the other can be NULL/0.
111 */
112void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
113			       const char *gname, unsigned int pin)
114{
115	const struct pinconf_ops *ops = pctldev->desc->confops;
116	int print_sep = 0;
117
118	if (!ops->is_generic)
119		return;
120
121	/* generic parameters */
122	pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
123				 ARRAY_SIZE(conf_items), &print_sep);
124	/* driver-specific parameters */
125	if (pctldev->desc->num_custom_params &&
126	    pctldev->desc->custom_conf_items)
127		pinconf_generic_dump_one(pctldev, s, gname, pin,
128					 pctldev->desc->custom_conf_items,
129					 pctldev->desc->num_custom_params,
130					 &print_sep);
131}
132
133void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
134				 struct seq_file *s, unsigned long config)
135{
136	int i;
137
138	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
139		if (pinconf_to_config_param(config) != conf_items[i].param)
140			continue;
141		seq_printf(s, "%s: 0x%x", conf_items[i].display,
142			   pinconf_to_config_argument(config));
143	}
144
145	if (!pctldev->desc->num_custom_params ||
146	    !pctldev->desc->custom_conf_items)
147		return;
148
149	for (i = 0; i < pctldev->desc->num_custom_params; i++) {
150		if (pinconf_to_config_param(config) !=
151		    pctldev->desc->custom_conf_items[i].param)
152			continue;
153		seq_printf(s, "%s: 0x%x",
154				pctldev->desc->custom_conf_items[i].display,
155				pinconf_to_config_argument(config));
156	}
157}
158EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
159#endif
160
161#ifdef CONFIG_OF
162static const struct pinconf_generic_params dt_params[] = {
163	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
164	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
165	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
166	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
167	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
168	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
169	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
170	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
171	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
172	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
173	{ "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },
174	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
175	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
176	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
177	{ "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
178	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
179	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
180	{ "low-power-disable", PIN_CONFIG_MODE_LOW_POWER, 0 },
181	{ "low-power-enable", PIN_CONFIG_MODE_LOW_POWER, 1 },
182	{ "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
183	{ "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
184	{ "output-high", PIN_CONFIG_OUTPUT, 1, },
185	{ "output-impedance-ohms", PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, 0 },
186	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
187	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
188	{ "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
189	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
190	{ "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
191};
192
193/**
194 * parse_dt_cfg() - Parse DT pinconf parameters
195 * @np:	DT node
196 * @params:	Array of describing generic parameters
197 * @count:	Number of entries in @params
198 * @cfg:	Array of parsed config options
199 * @ncfg:	Number of entries in @cfg
200 *
201 * Parse the config options described in @params from @np and puts the result
202 * in @cfg. @cfg does not need to be empty, entries are added beginning at
203 * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
204 * needs to have enough memory allocated to hold all possible entries.
205 */
206static void parse_dt_cfg(struct device_node *np,
207			 const struct pinconf_generic_params *params,
208			 unsigned int count, unsigned long *cfg,
209			 unsigned int *ncfg)
210{
211	int i;
212
213	for (i = 0; i < count; i++) {
214		u32 val;
215		int ret;
216		const struct pinconf_generic_params *par = &params[i];
217
218		ret = of_property_read_u32(np, par->property, &val);
219
220		/* property not found */
221		if (ret == -EINVAL)
222			continue;
223
224		/* use default value, when no value is specified */
225		if (ret)
226			val = par->default_value;
227
228		pr_debug("found %s with value %u\n", par->property, val);
229		cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
230		(*ncfg)++;
231	}
232}
233
234/**
235 * pinconf_generic_parse_dt_config()
236 * parse the config properties into generic pinconfig values.
237 * @np: node containing the pinconfig properties
238 * @pctldev: pincontrol device
239 * @configs: array with nconfigs entries containing the generic pinconf values
240 *           must be freed when no longer necessary.
241 * @nconfigs: number of configurations
242 */
243int pinconf_generic_parse_dt_config(struct device_node *np,
244				    struct pinctrl_dev *pctldev,
245				    unsigned long **configs,
246				    unsigned int *nconfigs)
247{
248	unsigned long *cfg;
249	unsigned int max_cfg, ncfg = 0;
250	int ret;
251
252	if (!np)
253		return -EINVAL;
254
255	/* allocate a temporary array big enough to hold one of each option */
256	max_cfg = ARRAY_SIZE(dt_params);
257	if (pctldev)
258		max_cfg += pctldev->desc->num_custom_params;
259	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
260	if (!cfg)
261		return -ENOMEM;
262
263	parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
264	if (pctldev && pctldev->desc->num_custom_params &&
265		pctldev->desc->custom_params)
266		parse_dt_cfg(np, pctldev->desc->custom_params,
267			     pctldev->desc->num_custom_params, cfg, &ncfg);
268
269	ret = 0;
270
271	/* no configs found at all */
272	if (ncfg == 0) {
273		*configs = NULL;
274		*nconfigs = 0;
275		goto out;
276	}
277
278	/*
279	 * Now limit the number of configs to the real number of
280	 * found properties.
281	 */
282	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
283	if (!*configs) {
284		ret = -ENOMEM;
285		goto out;
286	}
287
288	*nconfigs = ncfg;
289
290out:
291	kfree(cfg);
292	return ret;
293}
294EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);
295
296int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
297		struct device_node *np, struct pinctrl_map **map,
298		unsigned int *reserved_maps, unsigned int *num_maps,
299		enum pinctrl_map_type type)
300{
301	int ret;
302	const char *function;
303	struct device *dev = pctldev->dev;
304	unsigned long *configs = NULL;
305	unsigned int num_configs = 0;
306	unsigned int reserve, strings_count;
307	struct property *prop;
308	const char *group;
309	const char *subnode_target_type = "pins";
310
311	ret = of_property_count_strings(np, "pins");
312	if (ret < 0) {
313		ret = of_property_count_strings(np, "groups");
314		if (ret < 0)
315			/* skip this node; may contain config child nodes */
316			return 0;
317		if (type == PIN_MAP_TYPE_INVALID)
318			type = PIN_MAP_TYPE_CONFIGS_GROUP;
319		subnode_target_type = "groups";
320	} else {
321		if (type == PIN_MAP_TYPE_INVALID)
322			type = PIN_MAP_TYPE_CONFIGS_PIN;
323	}
324	strings_count = ret;
325
326	ret = of_property_read_string(np, "function", &function);
327	if (ret < 0) {
328		/* EINVAL=missing, which is fine since it's optional */
329		if (ret != -EINVAL)
330			dev_err(dev, "%pOF: could not parse property function\n",
331				np);
332		function = NULL;
333	}
334
335	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
336					      &num_configs);
337	if (ret < 0) {
338		dev_err(dev, "%pOF: could not parse node property\n", np);
339		return ret;
340	}
341
342	reserve = 0;
343	if (function != NULL)
344		reserve++;
345	if (num_configs)
346		reserve++;
347
348	reserve *= strings_count;
349
350	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
351			num_maps, reserve);
352	if (ret < 0)
353		goto exit;
354
355	of_property_for_each_string(np, subnode_target_type, prop, group) {
356		if (function) {
357			ret = pinctrl_utils_add_map_mux(pctldev, map,
358					reserved_maps, num_maps, group,
359					function);
360			if (ret < 0)
361				goto exit;
362		}
363
364		if (num_configs) {
365			ret = pinctrl_utils_add_map_configs(pctldev, map,
366					reserved_maps, num_maps, group, configs,
367					num_configs, type);
368			if (ret < 0)
369				goto exit;
370		}
371	}
372	ret = 0;
373
374exit:
375	kfree(configs);
376	return ret;
377}
378EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
379
380int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
381		struct device_node *np_config, struct pinctrl_map **map,
382		unsigned int *num_maps, enum pinctrl_map_type type)
383{
384	unsigned int reserved_maps;
385	struct device_node *np;
386	int ret;
387
388	reserved_maps = 0;
389	*map = NULL;
390	*num_maps = 0;
391
392	ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
393						&reserved_maps, num_maps, type);
394	if (ret < 0)
395		goto exit;
396
397	for_each_available_child_of_node(np_config, np) {
398		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
399					&reserved_maps, num_maps, type);
400		if (ret < 0) {
401			of_node_put(np);
402			goto exit;
403		}
404	}
405	return 0;
406
407exit:
408	pinctrl_utils_free_map(pctldev, *map, *num_maps);
409	return ret;
410}
411EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
412
413void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
414				 struct pinctrl_map *map,
415				 unsigned int num_maps)
416{
417	pinctrl_utils_free_map(pctldev, map, num_maps);
418}
419EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
420
421#endif
422