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