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_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 
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  */
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 
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 	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
171 	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
172 	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
173 	{ "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
174 	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
175 	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
176 	{ "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
177 	{ "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
178 	{ "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
179 	{ "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
180 	{ "output-high", PIN_CONFIG_OUTPUT, 1, },
181 	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
182 	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
183 	{ "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
184 	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
185 	{ "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
186 };
187 
188 /**
189  * parse_dt_cfg() - Parse DT pinconf parameters
190  * @np:	DT node
191  * @params:	Array of describing generic parameters
192  * @count:	Number of entries in @params
193  * @cfg:	Array of parsed config options
194  * @ncfg:	Number of entries in @cfg
195  *
196  * Parse the config options described in @params from @np and puts the result
197  * in @cfg. @cfg does not need to be empty, entries are added beginning at
198  * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
199  * needs to have enough memory allocated to hold all possible entries.
200  */
201 static void parse_dt_cfg(struct device_node *np,
202 			 const struct pinconf_generic_params *params,
203 			 unsigned int count, unsigned long *cfg,
204 			 unsigned int *ncfg)
205 {
206 	int i;
207 
208 	for (i = 0; i < count; i++) {
209 		u32 val;
210 		int ret;
211 		const struct pinconf_generic_params *par = &params[i];
212 
213 		ret = of_property_read_u32(np, par->property, &val);
214 
215 		/* property not found */
216 		if (ret == -EINVAL)
217 			continue;
218 
219 		/* use default value, when no value is specified */
220 		if (ret)
221 			val = par->default_value;
222 
223 		pr_debug("found %s with value %u\n", par->property, val);
224 		cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
225 		(*ncfg)++;
226 	}
227 }
228 
229 /**
230  * pinconf_generic_parse_dt_config()
231  * parse the config properties into generic pinconfig values.
232  * @np: node containing the pinconfig properties
233  * @configs: array with nconfigs entries containing the generic pinconf values
234  *           must be freed when no longer necessary.
235  * @nconfigs: umber of configurations
236  */
237 int pinconf_generic_parse_dt_config(struct device_node *np,
238 				    struct pinctrl_dev *pctldev,
239 				    unsigned long **configs,
240 				    unsigned int *nconfigs)
241 {
242 	unsigned long *cfg;
243 	unsigned int max_cfg, ncfg = 0;
244 	int ret;
245 
246 	if (!np)
247 		return -EINVAL;
248 
249 	/* allocate a temporary array big enough to hold one of each option */
250 	max_cfg = ARRAY_SIZE(dt_params);
251 	if (pctldev)
252 		max_cfg += pctldev->desc->num_custom_params;
253 	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
254 	if (!cfg)
255 		return -ENOMEM;
256 
257 	parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
258 	if (pctldev && pctldev->desc->num_custom_params &&
259 		pctldev->desc->custom_params)
260 		parse_dt_cfg(np, pctldev->desc->custom_params,
261 			     pctldev->desc->num_custom_params, cfg, &ncfg);
262 
263 	ret = 0;
264 
265 	/* no configs found at all */
266 	if (ncfg == 0) {
267 		*configs = NULL;
268 		*nconfigs = 0;
269 		goto out;
270 	}
271 
272 	/*
273 	 * Now limit the number of configs to the real number of
274 	 * found properties.
275 	 */
276 	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
277 	if (!*configs) {
278 		ret = -ENOMEM;
279 		goto out;
280 	}
281 
282 	*nconfigs = ncfg;
283 
284 out:
285 	kfree(cfg);
286 	return ret;
287 }
288 
289 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
290 		struct device_node *np, struct pinctrl_map **map,
291 		unsigned *reserved_maps, unsigned *num_maps,
292 		enum pinctrl_map_type type)
293 {
294 	int ret;
295 	const char *function;
296 	struct device *dev = pctldev->dev;
297 	unsigned long *configs = NULL;
298 	unsigned num_configs = 0;
299 	unsigned reserve, strings_count;
300 	struct property *prop;
301 	const char *group;
302 	const char *subnode_target_type = "pins";
303 
304 	ret = of_property_count_strings(np, "pins");
305 	if (ret < 0) {
306 		ret = of_property_count_strings(np, "groups");
307 		if (ret < 0)
308 			/* skip this node; may contain config child nodes */
309 			return 0;
310 		if (type == PIN_MAP_TYPE_INVALID)
311 			type = PIN_MAP_TYPE_CONFIGS_GROUP;
312 		subnode_target_type = "groups";
313 	} else {
314 		if (type == PIN_MAP_TYPE_INVALID)
315 			type = PIN_MAP_TYPE_CONFIGS_PIN;
316 	}
317 	strings_count = ret;
318 
319 	ret = of_property_read_string(np, "function", &function);
320 	if (ret < 0) {
321 		/* EINVAL=missing, which is fine since it's optional */
322 		if (ret != -EINVAL)
323 			dev_err(dev, "%pOF: could not parse property function\n",
324 				np);
325 		function = NULL;
326 	}
327 
328 	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
329 					      &num_configs);
330 	if (ret < 0) {
331 		dev_err(dev, "%pOF: could not parse node property\n", np);
332 		return ret;
333 	}
334 
335 	reserve = 0;
336 	if (function != NULL)
337 		reserve++;
338 	if (num_configs)
339 		reserve++;
340 
341 	reserve *= strings_count;
342 
343 	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
344 			num_maps, reserve);
345 	if (ret < 0)
346 		goto exit;
347 
348 	of_property_for_each_string(np, subnode_target_type, prop, group) {
349 		if (function) {
350 			ret = pinctrl_utils_add_map_mux(pctldev, map,
351 					reserved_maps, num_maps, group,
352 					function);
353 			if (ret < 0)
354 				goto exit;
355 		}
356 
357 		if (num_configs) {
358 			ret = pinctrl_utils_add_map_configs(pctldev, map,
359 					reserved_maps, num_maps, group, configs,
360 					num_configs, type);
361 			if (ret < 0)
362 				goto exit;
363 		}
364 	}
365 	ret = 0;
366 
367 exit:
368 	kfree(configs);
369 	return ret;
370 }
371 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
372 
373 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
374 		struct device_node *np_config, struct pinctrl_map **map,
375 		unsigned *num_maps, enum pinctrl_map_type type)
376 {
377 	unsigned reserved_maps;
378 	struct device_node *np;
379 	int ret;
380 
381 	reserved_maps = 0;
382 	*map = NULL;
383 	*num_maps = 0;
384 
385 	ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
386 						&reserved_maps, num_maps, type);
387 	if (ret < 0)
388 		goto exit;
389 
390 	for_each_available_child_of_node(np_config, np) {
391 		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
392 					&reserved_maps, num_maps, type);
393 		if (ret < 0)
394 			goto exit;
395 	}
396 	return 0;
397 
398 exit:
399 	pinctrl_utils_free_map(pctldev, *map, *num_maps);
400 	return ret;
401 }
402 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
403 
404 void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
405 				 struct pinctrl_map *map,
406 				 unsigned num_maps)
407 {
408 	pinctrl_utils_free_map(pctldev, map, num_maps);
409 }
410 EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);
411 
412 #endif
413