GNU Linux-libre 4.9.284-gnu1
[releases.git] / drivers / pinctrl / pinconf-generic.c
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