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