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