1 /*
2  * Core driver for the generic pin config portions of the pin control subsystem
3  *
4  * Copyright (C) 2011 ST-Ericsson SA
5  * Written on behalf of Linaro for ST-Ericsson
6  *
7  * Author: Linus Walleij <linus.walleij@linaro.org>
8  *
9  * License terms: GNU General Public License (GPL) version 2
10  */
11 
12 #define pr_fmt(fmt) "generic pinconfig core: " fmt
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/device.h>
18 #include <linux/slab.h>
19 #include <linux/debugfs.h>
20 #include <linux/seq_file.h>
21 #include <linux/pinctrl/pinctrl.h>
22 #include <linux/pinctrl/pinconf.h>
23 #include <linux/pinctrl/pinconf-generic.h>
24 #include <linux/of.h>
25 #include "core.h"
26 #include "pinconf.h"
27 #include "pinctrl-utils.h"
28 
29 #ifdef CONFIG_DEBUG_FS
30 static const struct pin_config_item conf_items[] = {
31 	PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
32 	PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
33 	PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
34 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL, false),
35 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
36 				"input bias pull to pin specific state", NULL, false),
37 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),
38 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
39 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
40 	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
41 	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", 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_SLEW_RATE, "slew rate", NULL, true),
51 };
52 
53 static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
54 				     struct seq_file *s, const char *gname,
55 				     unsigned pin,
56 				     const struct pin_config_item *items,
57 				     int nitems, int *print_sep)
58 {
59 	int i;
60 
61 	for (i = 0; i < nitems; i++) {
62 		unsigned long config;
63 		int ret;
64 
65 		/* We want to check out this parameter */
66 		config = pinconf_to_config_packed(items[i].param, 0);
67 		if (gname)
68 			ret = pin_config_group_get(dev_name(pctldev->dev),
69 						   gname, &config);
70 		else
71 			ret = pin_config_get_for_pin(pctldev, pin, &config);
72 		/* These are legal errors */
73 		if (ret == -EINVAL || ret == -ENOTSUPP)
74 			continue;
75 		if (ret) {
76 			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
77 			continue;
78 		}
79 		/* comma between multiple configs */
80 		if (*print_sep)
81 			seq_puts(s, ", ");
82 		*print_sep = 1;
83 		seq_puts(s, items[i].display);
84 		/* Print unit if available */
85 		if (items[i].has_arg) {
86 			seq_printf(s, " (%u",
87 				   pinconf_to_config_argument(config));
88 			if (items[i].format)
89 				seq_printf(s, " %s)", items[i].format);
90 			else
91 				seq_puts(s, ")");
92 		}
93 	}
94 }
95 
96 /**
97  * pinconf_generic_dump_pins - Print information about pin or group of pins
98  * @pctldev:	Pincontrol device
99  * @s:		File to print to
100  * @gname:	Group name specifying pins
101  * @pin:	Pin number specyfying pin
102  *
103  * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
104  * specified either by pin using @pin or by group using @gname. Only one needs
105  * to be specified the other can be NULL/0.
106  */
107 void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
108 			       const char *gname, unsigned pin)
109 {
110 	const struct pinconf_ops *ops = pctldev->desc->confops;
111 	int print_sep = 0;
112 
113 	if (!ops->is_generic)
114 		return;
115 
116 	/* generic parameters */
117 	pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
118 				 ARRAY_SIZE(conf_items), &print_sep);
119 	/* driver-specific parameters */
120 	if (pctldev->desc->num_custom_params &&
121 	    pctldev->desc->custom_conf_items)
122 		pinconf_generic_dump_one(pctldev, s, gname, pin,
123 					 pctldev->desc->custom_conf_items,
124 					 pctldev->desc->num_custom_params,
125 					 &print_sep);
126 }
127 
128 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
129 				 struct seq_file *s, unsigned long config)
130 {
131 	int i;
132 
133 	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
134 		if (pinconf_to_config_param(config) != conf_items[i].param)
135 			continue;
136 		seq_printf(s, "%s: 0x%x", conf_items[i].display,
137 			   pinconf_to_config_argument(config));
138 	}
139 
140 	if (!pctldev->desc->num_custom_params ||
141 	    !pctldev->desc->custom_conf_items)
142 		return;
143 
144 	for (i = 0; i < pctldev->desc->num_custom_params; i++) {
145 		if (pinconf_to_config_param(config) !=
146 		    pctldev->desc->custom_conf_items[i].param)
147 			continue;
148 		seq_printf(s, "%s: 0x%x",
149 				pctldev->desc->custom_conf_items[i].display,
150 				pinconf_to_config_argument(config));
151 	}
152 }
153 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
154 #endif
155 
156 #ifdef CONFIG_OF
157 static const struct pinconf_generic_params dt_params[] = {
158 	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
159 	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
160 	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
161 	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
162 	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
163 	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
164 	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
165 	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
166 	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
167 	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
168 	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
169 	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
170 	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
171 	{ "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
172 	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
173 	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
174 	{ "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
175 	{ "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
176 	{ "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
177 	{ "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
178 	{ "output-high", PIN_CONFIG_OUTPUT, 1, },
179 	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
180 	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
181 	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
182 };
183 
184 /**
185  * parse_dt_cfg() - Parse DT pinconf parameters
186  * @np:	DT node
187  * @params:	Array of describing generic parameters
188  * @count:	Number of entries in @params
189  * @cfg:	Array of parsed config options
190  * @ncfg:	Number of entries in @cfg
191  *
192  * Parse the config options described in @params from @np and puts the result
193  * in @cfg. @cfg does not need to be empty, entries are added beginning at
194  * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
195  * needs to have enough memory allocated to hold all possible entries.
196  */
197 static void parse_dt_cfg(struct device_node *np,
198 			 const struct pinconf_generic_params *params,
199 			 unsigned int count, unsigned long *cfg,
200 			 unsigned int *ncfg)
201 {
202 	int i;
203 
204 	for (i = 0; i < count; i++) {
205 		u32 val;
206 		int ret;
207 		const struct pinconf_generic_params *par = &params[i];
208 
209 		ret = of_property_read_u32(np, par->property, &val);
210 
211 		/* property not found */
212 		if (ret == -EINVAL)
213 			continue;
214 
215 		/* use default value, when no value is specified */
216 		if (ret)
217 			val = par->default_value;
218 
219 		pr_debug("found %s with value %u\n", par->property, val);
220 		cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
221 		(*ncfg)++;
222 	}
223 }
224 
225 /**
226  * pinconf_generic_parse_dt_config()
227  * parse the config properties into generic pinconfig values.
228  * @np: node containing the pinconfig properties
229  * @configs: array with nconfigs entries containing the generic pinconf values
230  *           must be freed when no longer necessary.
231  * @nconfigs: umber of configurations
232  */
233 int pinconf_generic_parse_dt_config(struct device_node *np,
234 				    struct pinctrl_dev *pctldev,
235 				    unsigned long **configs,
236 				    unsigned int *nconfigs)
237 {
238 	unsigned long *cfg;
239 	unsigned int max_cfg, ncfg = 0;
240 	int ret;
241 
242 	if (!np)
243 		return -EINVAL;
244 
245 	/* allocate a temporary array big enough to hold one of each option */
246 	max_cfg = ARRAY_SIZE(dt_params);
247 	if (pctldev)
248 		max_cfg += pctldev->desc->num_custom_params;
249 	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
250 	if (!cfg)
251 		return -ENOMEM;
252 
253 	parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
254 	if (pctldev && pctldev->desc->num_custom_params &&
255 		pctldev->desc->custom_params)
256 		parse_dt_cfg(np, pctldev->desc->custom_params,
257 			     pctldev->desc->num_custom_params, cfg, &ncfg);
258 
259 	ret = 0;
260 
261 	/* no configs found at all */
262 	if (ncfg == 0) {
263 		*configs = NULL;
264 		*nconfigs = 0;
265 		goto out;
266 	}
267 
268 	/*
269 	 * Now limit the number of configs to the real number of
270 	 * found properties.
271 	 */
272 	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
273 	if (!*configs) {
274 		ret = -ENOMEM;
275 		goto out;
276 	}
277 
278 	*nconfigs = ncfg;
279 
280 out:
281 	kfree(cfg);
282 	return ret;
283 }
284 
285 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
286 		struct device_node *np, struct pinctrl_map **map,
287 		unsigned *reserved_maps, unsigned *num_maps,
288 		enum pinctrl_map_type type)
289 {
290 	int ret;
291 	const char *function;
292 	struct device *dev = pctldev->dev;
293 	unsigned long *configs = NULL;
294 	unsigned num_configs = 0;
295 	unsigned reserve, strings_count;
296 	struct property *prop;
297 	const char *group;
298 	const char *subnode_target_type = "pins";
299 
300 	ret = of_property_count_strings(np, "pins");
301 	if (ret < 0) {
302 		ret = of_property_count_strings(np, "groups");
303 		if (ret < 0)
304 			/* skip this node; may contain config child nodes */
305 			return 0;
306 		if (type == PIN_MAP_TYPE_INVALID)
307 			type = PIN_MAP_TYPE_CONFIGS_GROUP;
308 		subnode_target_type = "groups";
309 	} else {
310 		if (type == PIN_MAP_TYPE_INVALID)
311 			type = PIN_MAP_TYPE_CONFIGS_PIN;
312 	}
313 	strings_count = ret;
314 
315 	ret = of_property_read_string(np, "function", &function);
316 	if (ret < 0) {
317 		/* EINVAL=missing, which is fine since it's optional */
318 		if (ret != -EINVAL)
319 			dev_err(dev, "%s: could not parse property function\n",
320 				of_node_full_name(np));
321 		function = NULL;
322 	}
323 
324 	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
325 					      &num_configs);
326 	if (ret < 0) {
327 		dev_err(dev, "%s: could not parse node property\n",
328 			of_node_full_name(np));
329 		return ret;
330 	}
331 
332 	reserve = 0;
333 	if (function != NULL)
334 		reserve++;
335 	if (num_configs)
336 		reserve++;
337 
338 	reserve *= strings_count;
339 
340 	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
341 			num_maps, reserve);
342 	if (ret < 0)
343 		goto exit;
344 
345 	of_property_for_each_string(np, subnode_target_type, prop, group) {
346 		if (function) {
347 			ret = pinctrl_utils_add_map_mux(pctldev, map,
348 					reserved_maps, num_maps, group,
349 					function);
350 			if (ret < 0)
351 				goto exit;
352 		}
353 
354 		if (num_configs) {
355 			ret = pinctrl_utils_add_map_configs(pctldev, map,
356 					reserved_maps, num_maps, group, configs,
357 					num_configs, type);
358 			if (ret < 0)
359 				goto exit;
360 		}
361 	}
362 	ret = 0;
363 
364 exit:
365 	kfree(configs);
366 	return ret;
367 }
368 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
369 
370 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
371 		struct device_node *np_config, struct pinctrl_map **map,
372 		unsigned *num_maps, enum pinctrl_map_type type)
373 {
374 	unsigned reserved_maps;
375 	struct device_node *np;
376 	int ret;
377 
378 	reserved_maps = 0;
379 	*map = NULL;
380 	*num_maps = 0;
381 
382 	ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
383 						&reserved_maps, num_maps, type);
384 	if (ret < 0)
385 		goto exit;
386 
387 	for_each_available_child_of_node(np_config, np) {
388 		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
389 					&reserved_maps, num_maps, type);
390 		if (ret < 0)
391 			goto exit;
392 	}
393 	return 0;
394 
395 exit:
396 	pinctrl_utils_free_map(pctldev, *map, *num_maps);
397 	return ret;
398 }
399 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
400 
401 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
402 				 struct pinctrl_map *map,
403 				 unsigned num_maps)
404 {
405 	pinctrl_utils_free_map(pctldev, map, num_maps);
406 }
407 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
408 
409 #endif
410