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
pinconf_generic_dump_one(struct pinctrl_dev * pctldev,struct seq_file * s,const char * gname,unsigned int pin,const struct pin_config_item * items,int nitems,int * print_sep)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 seq_printf(s, " (0x%x",
93 pinconf_to_config_argument(config));
94 if (items[i].format)
95 seq_printf(s, " %s)", items[i].format);
96 else
97 seq_puts(s, ")");
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 */
pinconf_generic_dump_pins(struct pinctrl_dev * pctldev,struct seq_file * s,const char * gname,unsigned int pin)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
pinconf_generic_dump_config(struct pinctrl_dev * pctldev,struct seq_file * s,unsigned long config)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 */
parse_dt_cfg(struct device_node * np,const struct pinconf_generic_params * params,unsigned int count,unsigned long * cfg,unsigned int * ncfg)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 = ¶ms[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_config()
238 * parse the config properties into generic pinconfig values.
239 * @np: node containing the pinconfig properties
240 * @pctldev: pincontrol device
241 * @configs: array with nconfigs entries containing the generic pinconf values
242 * must be freed when no longer necessary.
243 * @nconfigs: number of configurations
244 */
pinconf_generic_parse_dt_config(struct device_node * np,struct pinctrl_dev * pctldev,unsigned long ** configs,unsigned int * nconfigs)245 int pinconf_generic_parse_dt_config(struct device_node *np,
246 struct pinctrl_dev *pctldev,
247 unsigned long **configs,
248 unsigned int *nconfigs)
249 {
250 unsigned long *cfg;
251 unsigned int max_cfg, ncfg = 0;
252 int ret;
253
254 if (!np)
255 return -EINVAL;
256
257 /* allocate a temporary array big enough to hold one of each option */
258 max_cfg = ARRAY_SIZE(dt_params);
259 if (pctldev)
260 max_cfg += pctldev->desc->num_custom_params;
261 cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
262 if (!cfg)
263 return -ENOMEM;
264
265 parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
266 if (pctldev && pctldev->desc->num_custom_params &&
267 pctldev->desc->custom_params)
268 parse_dt_cfg(np, pctldev->desc->custom_params,
269 pctldev->desc->num_custom_params, cfg, &ncfg);
270
271 ret = 0;
272
273 /* no configs found at all */
274 if (ncfg == 0) {
275 *configs = NULL;
276 *nconfigs = 0;
277 goto out;
278 }
279
280 /*
281 * Now limit the number of configs to the real number of
282 * found properties.
283 */
284 *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
285 if (!*configs) {
286 ret = -ENOMEM;
287 goto out;
288 }
289
290 *nconfigs = ncfg;
291
292 out:
293 kfree(cfg);
294 return ret;
295 }
296 EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);
297
pinconf_generic_dt_subnode_to_map(struct pinctrl_dev * pctldev,struct device_node * np,struct pinctrl_map ** map,unsigned int * reserved_maps,unsigned int * num_maps,enum pinctrl_map_type type)298 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
299 struct device_node *np, struct pinctrl_map **map,
300 unsigned int *reserved_maps, unsigned int *num_maps,
301 enum pinctrl_map_type type)
302 {
303 int ret;
304 const char *function;
305 struct device *dev = pctldev->dev;
306 unsigned long *configs = NULL;
307 unsigned int num_configs = 0;
308 unsigned int reserve, strings_count;
309 struct property *prop;
310 const char *group;
311 const char *subnode_target_type = "pins";
312
313 ret = of_property_count_strings(np, "pins");
314 if (ret < 0) {
315 ret = of_property_count_strings(np, "groups");
316 if (ret < 0)
317 /* skip this node; may contain config child nodes */
318 return 0;
319 if (type == PIN_MAP_TYPE_INVALID)
320 type = PIN_MAP_TYPE_CONFIGS_GROUP;
321 subnode_target_type = "groups";
322 } else {
323 if (type == PIN_MAP_TYPE_INVALID)
324 type = PIN_MAP_TYPE_CONFIGS_PIN;
325 }
326 strings_count = ret;
327
328 ret = of_property_read_string(np, "function", &function);
329 if (ret < 0) {
330 /* EINVAL=missing, which is fine since it's optional */
331 if (ret != -EINVAL)
332 dev_err(dev, "%pOF: could not parse property function\n",
333 np);
334 function = NULL;
335 }
336
337 ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
338 &num_configs);
339 if (ret < 0) {
340 dev_err(dev, "%pOF: could not parse node property\n", np);
341 return ret;
342 }
343
344 reserve = 0;
345 if (function != NULL)
346 reserve++;
347 if (num_configs)
348 reserve++;
349
350 reserve *= strings_count;
351
352 ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
353 num_maps, reserve);
354 if (ret < 0)
355 goto exit;
356
357 of_property_for_each_string(np, subnode_target_type, prop, group) {
358 if (function) {
359 ret = pinctrl_utils_add_map_mux(pctldev, map,
360 reserved_maps, num_maps, group,
361 function);
362 if (ret < 0)
363 goto exit;
364 }
365
366 if (num_configs) {
367 ret = pinctrl_utils_add_map_configs(pctldev, map,
368 reserved_maps, num_maps, group, configs,
369 num_configs, type);
370 if (ret < 0)
371 goto exit;
372 }
373 }
374 ret = 0;
375
376 exit:
377 kfree(configs);
378 return ret;
379 }
380 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
381
pinconf_generic_dt_node_to_map(struct pinctrl_dev * pctldev,struct device_node * np_config,struct pinctrl_map ** map,unsigned int * num_maps,enum pinctrl_map_type type)382 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
383 struct device_node *np_config, struct pinctrl_map **map,
384 unsigned int *num_maps, enum pinctrl_map_type type)
385 {
386 unsigned int reserved_maps;
387 int ret;
388
389 reserved_maps = 0;
390 *map = NULL;
391 *num_maps = 0;
392
393 ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
394 &reserved_maps, num_maps, type);
395 if (ret < 0)
396 goto exit;
397
398 for_each_available_child_of_node_scoped(np_config, np) {
399 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
400 &reserved_maps, num_maps, type);
401 if (ret < 0)
402 goto exit;
403 }
404 return 0;
405
406 exit:
407 pinctrl_utils_free_map(pctldev, *map, *num_maps);
408 return ret;
409 }
410 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
411
pinconf_generic_dt_free_map(struct pinctrl_dev * pctldev,struct pinctrl_map * map,unsigned int num_maps)412 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
413 struct pinctrl_map *map,
414 unsigned int num_maps)
415 {
416 pinctrl_utils_free_map(pctldev, map, num_maps);
417 }
418 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
419
420 #endif
421