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 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(param: items[i].param, argument: 0);
72 if (gname)
73 ret = pin_config_group_get(dev_name: dev_name(dev: pctldev->dev),
74 pin_group: gname, config: &config);
75 else
76 ret = pin_config_get_for_pin(pctldev, pin, config: &config);
77 /* These are legal errors */
78 if (ret == -EINVAL || ret == -ENOTSUPP)
79 continue;
80 if (ret) {
81 seq_printf(m: s, fmt: "ERROR READING CONFIG SETTING %d ", i);
82 continue;
83 }
84 /* comma between multiple configs */
85 if (*print_sep)
86 seq_puts(m: s, s: ", ");
87 *print_sep = 1;
88 seq_puts(m: s, s: items[i].display);
89 /* Print unit if available */
90 if (items[i].has_arg) {
91 seq_printf(m: s, fmt: " (%u",
92 pinconf_to_config_argument(config));
93 if (items[i].format)
94 seq_printf(m: s, fmt: " %s)", items[i].format);
95 else
96 seq_puts(m: s, 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 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, items: conf_items,
123 ARRAY_SIZE(conf_items), print_sep: &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 items: pctldev->desc->custom_conf_items,
129 nitems: pctldev->desc->num_custom_params,
130 print_sep: &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(m: s, fmt: "%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(m: s, fmt: "%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, propname: par->property, out_value: &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(param: par->param, argument: 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(n: max_cfg, size: sizeof(*cfg), GFP_KERNEL);
260 if (!cfg)
261 return -ENOMEM;
262
263 parse_dt_cfg(np, params: dt_params, ARRAY_SIZE(dt_params), cfg, ncfg: &ncfg);
264 if (pctldev && pctldev->desc->num_custom_params &&
265 pctldev->desc->custom_params)
266 parse_dt_cfg(np, params: pctldev->desc->custom_params,
267 count: pctldev->desc->num_custom_params, cfg, ncfg: &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(p: cfg, size: ncfg * sizeof(unsigned long), GFP_KERNEL);
283 if (!*configs) {
284 ret = -ENOMEM;
285 goto out;
286 }
287
288 *nconfigs = ncfg;
289
290out:
291 kfree(objp: 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 *reserved_maps, unsigned *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 num_configs = 0;
306 unsigned 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, propname: "pins");
312 if (ret < 0) {
313 ret = of_property_count_strings(np, propname: "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, propname: "function", out_string: &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(objp: 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 *num_maps, enum pinctrl_map_type type)
383{
384 unsigned 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(node: np);
402 goto exit;
403 }
404 }
405 return 0;
406
407exit:
408 pinctrl_utils_free_map(pctldev, map: *map, num_maps: *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 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

source code of linux/drivers/pinctrl/pinconf-generic.c