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_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 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) 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 */ 104 void 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 } 122 123 void 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 } 148 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config); 149 #endif 150 151 #ifdef CONFIG_OF 152 static 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 */ 189 static 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 = ¶ms[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 */ 224 int 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; 270 271 out: 272 kfree(cfg); 273 return ret; 274 } 275 276 int 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; 287 struct property *prop; 288 const char *group; 289 const char *subnode_target_type = "pins"; 290 291 ret = of_property_read_string(np, "function", &function); 292 if (ret < 0) { 293 /* EINVAL=missing, which is fine since it's optional */ 294 if (ret != -EINVAL) 295 dev_err(dev, "could not parse property function\n"); 296 function = NULL; 297 } 298 299 ret = pinconf_generic_parse_dt_config(np, pctldev, &configs, 300 &num_configs); 301 if (ret < 0) { 302 dev_err(dev, "could not parse node property\n"); 303 return ret; 304 } 305 306 reserve = 0; 307 if (function != NULL) 308 reserve++; 309 if (num_configs) 310 reserve++; 311 312 ret = of_property_count_strings(np, "pins"); 313 if (ret < 0) { 314 ret = of_property_count_strings(np, "groups"); 315 if (ret < 0) { 316 dev_err(dev, "could not parse property pins/groups\n"); 317 goto exit; 318 } 319 if (type == PIN_MAP_TYPE_INVALID) 320 type = PIN_MAP_TYPE_CONFIGS_GROUP; 321 subnode_target_type = "groups"; 322 } else { 323 if (type == PIN_MAP_TYPE_INVALID) 324 type = PIN_MAP_TYPE_CONFIGS_PIN; 325 } 326 reserve *= ret; 327 328 ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps, 329 num_maps, reserve); 330 if (ret < 0) 331 goto exit; 332 333 of_property_for_each_string(np, subnode_target_type, prop, group) { 334 if (function) { 335 ret = pinctrl_utils_add_map_mux(pctldev, map, 336 reserved_maps, num_maps, group, 337 function); 338 if (ret < 0) 339 goto exit; 340 } 341 342 if (num_configs) { 343 ret = pinctrl_utils_add_map_configs(pctldev, map, 344 reserved_maps, num_maps, group, configs, 345 num_configs, type); 346 if (ret < 0) 347 goto exit; 348 } 349 } 350 ret = 0; 351 352 exit: 353 kfree(configs); 354 return ret; 355 } 356 EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map); 357 358 int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev, 359 struct device_node *np_config, struct pinctrl_map **map, 360 unsigned *num_maps, enum pinctrl_map_type type) 361 { 362 unsigned reserved_maps; 363 struct device_node *np; 364 int ret; 365 366 reserved_maps = 0; 367 *map = NULL; 368 *num_maps = 0; 369 370 for_each_child_of_node(np_config, np) { 371 ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map, 372 &reserved_maps, num_maps, type); 373 if (ret < 0) { 374 pinctrl_utils_dt_free_map(pctldev, *map, *num_maps); 375 return ret; 376 } 377 } 378 return 0; 379 } 380 EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map); 381 382 #endif 383