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 
31 struct pin_config_item {
32 	const enum pin_config_param param;
33 	const char * const display;
34 	const char * const format;
35 };
36 
37 #define PCONFDUMP(a, b, c) { .param = a, .display = b, .format = c }
38 
39 static struct pin_config_item conf_items[] = {
40 	PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL),
41 	PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL),
42 	PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL),
43 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL),
44 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL),
45 	PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
46 				"input bias pull to pin specific state", NULL),
47 	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL),
48 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL),
49 	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL),
50 	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA"),
51 	PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL),
52 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL),
53 	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL),
54 	PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec"),
55 	PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector"),
56 	PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL),
57 	PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode"),
58 	PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level"),
59 };
60 
61 void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
62 			      struct seq_file *s, unsigned pin)
63 {
64 	const struct pinconf_ops *ops = pctldev->desc->confops;
65 	int i;
66 
67 	if (!ops->is_generic)
68 		return;
69 
70 	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
71 		unsigned long config;
72 		int ret;
73 
74 		/* We want to check out this parameter */
75 		config = pinconf_to_config_packed(conf_items[i].param, 0);
76 		ret = pin_config_get_for_pin(pctldev, pin, &config);
77 		/* These are legal errors */
78 		if (ret == -EINVAL || ret == -ENOTSUPP)
79 			continue;
80 		if (ret) {
81 			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
82 			continue;
83 		}
84 		/* Space between multiple configs */
85 		seq_puts(s, " ");
86 		seq_puts(s, conf_items[i].display);
87 		/* Print unit if available */
88 		if (conf_items[i].format &&
89 		    pinconf_to_config_argument(config) != 0)
90 			seq_printf(s, " (%u %s)",
91 				   pinconf_to_config_argument(config),
92 				   conf_items[i].format);
93 	}
94 }
95 
96 void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
97 			      struct seq_file *s, const char *gname)
98 {
99 	const struct pinconf_ops *ops = pctldev->desc->confops;
100 	int i;
101 
102 	if (!ops->is_generic)
103 		return;
104 
105 	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
106 		unsigned long config;
107 		int ret;
108 
109 		/* We want to check out this parameter */
110 		config = pinconf_to_config_packed(conf_items[i].param, 0);
111 		ret = pin_config_group_get(dev_name(pctldev->dev), gname,
112 					   &config);
113 		/* These are legal errors */
114 		if (ret == -EINVAL || ret == -ENOTSUPP)
115 			continue;
116 		if (ret) {
117 			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
118 			continue;
119 		}
120 		/* Space between multiple configs */
121 		seq_puts(s, " ");
122 		seq_puts(s, conf_items[i].display);
123 		/* Print unit if available */
124 		if (conf_items[i].format && config != 0)
125 			seq_printf(s, " (%u %s)",
126 				   pinconf_to_config_argument(config),
127 				   conf_items[i].format);
128 	}
129 }
130 
131 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
132 				 struct seq_file *s, unsigned long config)
133 {
134 	int i;
135 
136 	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
137 		if (pinconf_to_config_param(config) != conf_items[i].param)
138 			continue;
139 		seq_printf(s, "%s: 0x%x", conf_items[i].display,
140 			   pinconf_to_config_argument(config));
141 	}
142 }
143 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
144 #endif
145 
146 #ifdef CONFIG_OF
147 struct pinconf_generic_dt_params {
148 	const char * const property;
149 	enum pin_config_param param;
150 	u32 default_value;
151 };
152 
153 static struct pinconf_generic_dt_params dt_params[] = {
154 	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
155 	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
156 	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
157 	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
158 	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
159 	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
160 	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
161 	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
162 	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
163 	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
164 	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
165 	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
166 	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
167 	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
168 	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
169 	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
170 	{ "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
171 	{ "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
172 	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
173 	{ "output-high", PIN_CONFIG_OUTPUT, 1, },
174 	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0},
175 };
176 
177 /**
178  * pinconf_generic_parse_dt_config()
179  * parse the config properties into generic pinconfig values.
180  * @np: node containing the pinconfig properties
181  * @configs: array with nconfigs entries containing the generic pinconf values
182  * @nconfigs: umber of configurations
183  */
184 int pinconf_generic_parse_dt_config(struct device_node *np,
185 				    unsigned long **configs,
186 				    unsigned int *nconfigs)
187 {
188 	unsigned long *cfg;
189 	unsigned int ncfg = 0;
190 	int ret;
191 	int i;
192 	u32 val;
193 
194 	if (!np)
195 		return -EINVAL;
196 
197 	/* allocate a temporary array big enough to hold one of each option */
198 	cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL);
199 	if (!cfg)
200 		return -ENOMEM;
201 
202 	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
203 		struct pinconf_generic_dt_params *par = &dt_params[i];
204 		ret = of_property_read_u32(np, par->property, &val);
205 
206 		/* property not found */
207 		if (ret == -EINVAL)
208 			continue;
209 
210 		/* use default value, when no value is specified */
211 		if (ret)
212 			val = par->default_value;
213 
214 		pr_debug("found %s with value %u\n", par->property, val);
215 		cfg[ncfg] = pinconf_to_config_packed(par->param, val);
216 		ncfg++;
217 	}
218 
219 	ret = 0;
220 
221 	/* no configs found at all */
222 	if (ncfg == 0) {
223 		*configs = NULL;
224 		*nconfigs = 0;
225 		goto out;
226 	}
227 
228 	/*
229 	 * Now limit the number of configs to the real number of
230 	 * found properties.
231 	 */
232 	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
233 	if (!*configs) {
234 		ret = -ENOMEM;
235 		goto out;
236 	}
237 
238 	*nconfigs = ncfg;
239 
240 out:
241 	kfree(cfg);
242 	return ret;
243 }
244 
245 int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
246 		struct device_node *np, struct pinctrl_map **map,
247 		unsigned *reserved_maps, unsigned *num_maps,
248 		enum pinctrl_map_type type)
249 {
250 	int ret;
251 	const char *function;
252 	struct device *dev = pctldev->dev;
253 	unsigned long *configs = NULL;
254 	unsigned num_configs = 0;
255 	unsigned reserve;
256 	struct property *prop;
257 	const char *group;
258 
259 	ret = of_property_read_string(np, "function", &function);
260 	if (ret < 0) {
261 		/* EINVAL=missing, which is fine since it's optional */
262 		if (ret != -EINVAL)
263 			dev_err(dev, "could not parse property function\n");
264 		function = NULL;
265 	}
266 
267 	ret = pinconf_generic_parse_dt_config(np, &configs, &num_configs);
268 	if (ret < 0) {
269 		dev_err(dev, "could not parse node property\n");
270 		return ret;
271 	}
272 
273 	reserve = 0;
274 	if (function != NULL)
275 		reserve++;
276 	if (num_configs)
277 		reserve++;
278 	ret = of_property_count_strings(np, "pins");
279 	if (ret < 0) {
280 		dev_err(dev, "could not parse property pins\n");
281 		goto exit;
282 	}
283 	reserve *= ret;
284 
285 	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
286 			num_maps, reserve);
287 	if (ret < 0)
288 		goto exit;
289 
290 	of_property_for_each_string(np, "pins", prop, group) {
291 		if (function) {
292 			ret = pinctrl_utils_add_map_mux(pctldev, map,
293 					reserved_maps, num_maps, group,
294 					function);
295 			if (ret < 0)
296 				goto exit;
297 		}
298 
299 		if (num_configs) {
300 			ret = pinctrl_utils_add_map_configs(pctldev, map,
301 					reserved_maps, num_maps, group, configs,
302 					num_configs, type);
303 			if (ret < 0)
304 				goto exit;
305 		}
306 	}
307 	ret = 0;
308 
309 exit:
310 	kfree(configs);
311 	return ret;
312 }
313 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
314 
315 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
316 		struct device_node *np_config, struct pinctrl_map **map,
317 		unsigned *num_maps, enum pinctrl_map_type type)
318 {
319 	unsigned reserved_maps;
320 	struct device_node *np;
321 	int ret;
322 
323 	reserved_maps = 0;
324 	*map = NULL;
325 	*num_maps = 0;
326 
327 	for_each_child_of_node(np_config, np) {
328 		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
329 					&reserved_maps, num_maps, type);
330 		if (ret < 0) {
331 			pinctrl_utils_dt_free_map(pctldev, *map, *num_maps);
332 			return ret;
333 		}
334 	}
335 	return 0;
336 }
337 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
338 
339 #endif
340