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
30static const struct pin_config_item conf_items[] = {
31	PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
32	PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
33	PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
34	PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),
35	PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL, false),
36	PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
37				"input bias pull to pin specific state", NULL, false),
38	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
39	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
40	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
41	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
42	PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
43	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
44	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
45	PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
46	PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
47	PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
48	PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode", true),
49	PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
50};
51
52static 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)
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		/* Space between multiple configs */
79		seq_puts(s, " ");
80		seq_puts(s, items[i].display);
81		/* Print unit if available */
82		if (items[i].has_arg) {
83			seq_printf(s, " (%u",
84				   pinconf_to_config_argument(config));
85			if (items[i].format)
86				seq_printf(s, " %s)", items[i].format);
87			else
88				seq_puts(s, ")");
89		}
90	}
91}
92
93/**
94 * pinconf_generic_dump_pins - Print information about pin or group of pins
95 * @pctldev:	Pincontrol device
96 * @s:		File to print to
97 * @gname:	Group name specifying pins
98 * @pin:	Pin number specyfying pin
99 *
100 * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
101 * specified either by pin using @pin or by group using @gname. Only one needs
102 * to be specified the other can be NULL/0.
103 */
104void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
105			       const char *gname, unsigned pin)
106{
107	const struct pinconf_ops *ops = pctldev->desc->confops;
108
109	if (!ops->is_generic)
110		return;
111
112	/* generic parameters */
113	pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
114				 ARRAY_SIZE(conf_items));
115	/* driver-specific parameters */
116	if (pctldev->desc->num_custom_params &&
117	    pctldev->desc->custom_conf_items)
118		pinconf_generic_dump_one(pctldev, s, gname, pin,
119					 pctldev->desc->custom_conf_items,
120					 pctldev->desc->num_custom_params);
121}
122
123void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
124				 struct seq_file *s, unsigned long config)
125{
126	int i;
127
128	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
129		if (pinconf_to_config_param(config) != conf_items[i].param)
130			continue;
131		seq_printf(s, "%s: 0x%x", conf_items[i].display,
132			   pinconf_to_config_argument(config));
133	}
134
135	if (!pctldev->desc->num_custom_params ||
136	    !pctldev->desc->custom_conf_items)
137		return;
138
139	for (i = 0; i < pctldev->desc->num_custom_params; i++) {
140		if (pinconf_to_config_param(config) !=
141		    pctldev->desc->custom_conf_items[i].param)
142			continue;
143		seq_printf(s, "%s: 0x%x",
144				pctldev->desc->custom_conf_items[i].display,
145				pinconf_to_config_argument(config));
146	}
147}
148EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
149#endif
150
151#ifdef CONFIG_OF
152static const struct pinconf_generic_params dt_params[] = {
153	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
154	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
155	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
156	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
157	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
158	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
159	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
160	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
161	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
162	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
163	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
164	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
165	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
166	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
167	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
168	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
169	{ "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },
170	{ "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },
171	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
172	{ "output-high", PIN_CONFIG_OUTPUT, 1, },
173	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0},
174};
175
176/**
177 * parse_dt_cfg() - Parse DT pinconf parameters
178 * @np:	DT node
179 * @params:	Array of describing generic parameters
180 * @count:	Number of entries in @params
181 * @cfg:	Array of parsed config options
182 * @ncfg:	Number of entries in @cfg
183 *
184 * Parse the config options described in @params from @np and puts the result
185 * in @cfg. @cfg does not need to be empty, entries are added beggining at
186 * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
187 * needs to have enough memory allocated to hold all possible entries.
188 */
189static void parse_dt_cfg(struct device_node *np,
190			 const struct pinconf_generic_params *params,
191			 unsigned int count, unsigned long *cfg,
192			 unsigned int *ncfg)
193{
194	int i;
195
196	for (i = 0; i < count; i++) {
197		u32 val;
198		int ret;
199		const struct pinconf_generic_params *par = &params[i];
200
201		ret = of_property_read_u32(np, par->property, &val);
202
203		/* property not found */
204		if (ret == -EINVAL)
205			continue;
206
207		/* use default value, when no value is specified */
208		if (ret)
209			val = par->default_value;
210
211		pr_debug("found %s with value %u\n", par->property, val);
212		cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
213		(*ncfg)++;
214	}
215}
216
217/**
218 * pinconf_generic_parse_dt_config()
219 * parse the config properties into generic pinconfig values.
220 * @np: node containing the pinconfig properties
221 * @configs: array with nconfigs entries containing the generic pinconf values
222 * @nconfigs: umber of configurations
223 */
224int pinconf_generic_parse_dt_config(struct device_node *np,
225				    struct pinctrl_dev *pctldev,
226				    unsigned long **configs,
227				    unsigned int *nconfigs)
228{
229	unsigned long *cfg;
230	unsigned int max_cfg, ncfg = 0;
231	int ret;
232
233	if (!np)
234		return -EINVAL;
235
236	/* allocate a temporary array big enough to hold one of each option */
237	max_cfg = ARRAY_SIZE(dt_params);
238	if (pctldev)
239		max_cfg += pctldev->desc->num_custom_params;
240	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
241	if (!cfg)
242		return -ENOMEM;
243
244	parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
245	if (pctldev && pctldev->desc->num_custom_params &&
246		pctldev->desc->custom_params)
247		parse_dt_cfg(np, pctldev->desc->custom_params,
248			     pctldev->desc->num_custom_params, cfg, &ncfg);
249
250	ret = 0;
251
252	/* no configs found at all */
253	if (ncfg == 0) {
254		*configs = NULL;
255		*nconfigs = 0;
256		goto out;
257	}
258
259	/*
260	 * Now limit the number of configs to the real number of
261	 * found properties.
262	 */
263	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
264	if (!*configs) {
265		ret = -ENOMEM;
266		goto out;
267	}
268
269	*nconfigs = ncfg;
270
271out:
272	kfree(cfg);
273	return ret;
274}
275
276int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
277		struct device_node *np, struct pinctrl_map **map,
278		unsigned *reserved_maps, unsigned *num_maps,
279		enum pinctrl_map_type type)
280{
281	int ret;
282	const char *function;
283	struct device *dev = pctldev->dev;
284	unsigned long *configs = NULL;
285	unsigned num_configs = 0;
286	unsigned reserve, strings_count;
287	struct property *prop;
288	const char *group;
289	const char *subnode_target_type = "pins";
290
291	ret = of_property_count_strings(np, "pins");
292	if (ret < 0) {
293		ret = of_property_count_strings(np, "groups");
294		if (ret < 0)
295			/* skip this node; may contain config child nodes */
296			return 0;
297		if (type == PIN_MAP_TYPE_INVALID)
298			type = PIN_MAP_TYPE_CONFIGS_GROUP;
299		subnode_target_type = "groups";
300	} else {
301		if (type == PIN_MAP_TYPE_INVALID)
302			type = PIN_MAP_TYPE_CONFIGS_PIN;
303	}
304	strings_count = ret;
305
306	ret = of_property_read_string(np, "function", &function);
307	if (ret < 0) {
308		/* EINVAL=missing, which is fine since it's optional */
309		if (ret != -EINVAL)
310			dev_err(dev, "%s: could not parse property function\n",
311				of_node_full_name(np));
312		function = NULL;
313	}
314
315	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
316					      &num_configs);
317	if (ret < 0) {
318		dev_err(dev, "%s: could not parse node property\n",
319			of_node_full_name(np));
320		return ret;
321	}
322
323	reserve = 0;
324	if (function != NULL)
325		reserve++;
326	if (num_configs)
327		reserve++;
328
329	reserve *= strings_count;
330
331	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
332			num_maps, reserve);
333	if (ret < 0)
334		goto exit;
335
336	of_property_for_each_string(np, subnode_target_type, prop, group) {
337		if (function) {
338			ret = pinctrl_utils_add_map_mux(pctldev, map,
339					reserved_maps, num_maps, group,
340					function);
341			if (ret < 0)
342				goto exit;
343		}
344
345		if (num_configs) {
346			ret = pinctrl_utils_add_map_configs(pctldev, map,
347					reserved_maps, num_maps, group, configs,
348					num_configs, type);
349			if (ret < 0)
350				goto exit;
351		}
352	}
353	ret = 0;
354
355exit:
356	kfree(configs);
357	return ret;
358}
359EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
360
361int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
362		struct device_node *np_config, struct pinctrl_map **map,
363		unsigned *num_maps, enum pinctrl_map_type type)
364{
365	unsigned reserved_maps;
366	struct device_node *np;
367	int ret;
368
369	reserved_maps = 0;
370	*map = NULL;
371	*num_maps = 0;
372
373	ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
374						&reserved_maps, num_maps, type);
375	if (ret < 0)
376		goto exit;
377
378	for_each_child_of_node(np_config, np) {
379		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
380					&reserved_maps, num_maps, type);
381		if (ret < 0)
382			goto exit;
383	}
384	return 0;
385
386exit:
387	pinctrl_utils_dt_free_map(pctldev, *map, *num_maps);
388	return ret;
389}
390EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);
391
392#endif
393