Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Generic pwmlib implementation |
| 3 | * |
| 4 | * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de> |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 5 | * Copyright (C) 2011-2012 Avionic Design GmbH |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2, or (at your option) |
| 10 | * any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; see the file COPYING. If not, write to |
| 19 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. |
| 20 | */ |
| 21 | |
| 22 | #include <linux/module.h> |
| 23 | #include <linux/pwm.h> |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 24 | #include <linux/radix-tree.h> |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 25 | #include <linux/list.h> |
| 26 | #include <linux/mutex.h> |
| 27 | #include <linux/err.h> |
| 28 | #include <linux/slab.h> |
| 29 | #include <linux/device.h> |
Thierry Reding | 62099ab | 2012-03-26 09:31:48 +0200 | [diff] [blame] | 30 | #include <linux/debugfs.h> |
| 31 | #include <linux/seq_file.h> |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 32 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 33 | #define MAX_PWMS 1024 |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 34 | |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 35 | static DEFINE_MUTEX(pwm_lookup_lock); |
| 36 | static LIST_HEAD(pwm_lookup_list); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 37 | static DEFINE_MUTEX(pwm_lock); |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 38 | static LIST_HEAD(pwm_chips); |
| 39 | static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); |
| 40 | static RADIX_TREE(pwm_tree, GFP_KERNEL); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 41 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 42 | static struct pwm_device *pwm_to_device(unsigned int pwm) |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 43 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 44 | return radix_tree_lookup(&pwm_tree, pwm); |
| 45 | } |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 46 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 47 | static int alloc_pwms(int pwm, unsigned int count) |
| 48 | { |
| 49 | unsigned int from = 0; |
| 50 | unsigned int start; |
| 51 | |
| 52 | if (pwm >= MAX_PWMS) |
| 53 | return -EINVAL; |
| 54 | |
| 55 | if (pwm >= 0) |
| 56 | from = pwm; |
| 57 | |
| 58 | start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
| 59 | count, 0); |
| 60 | |
| 61 | if (pwm >= 0 && start != pwm) |
| 62 | return -EEXIST; |
| 63 | |
| 64 | if (start + count > MAX_PWMS) |
| 65 | return -ENOSPC; |
| 66 | |
| 67 | return start; |
| 68 | } |
| 69 | |
| 70 | static void free_pwms(struct pwm_chip *chip) |
| 71 | { |
| 72 | unsigned int i; |
| 73 | |
| 74 | for (i = 0; i < chip->npwm; i++) { |
| 75 | struct pwm_device *pwm = &chip->pwms[i]; |
| 76 | radix_tree_delete(&pwm_tree, pwm->pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 77 | } |
| 78 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 79 | bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
| 80 | |
| 81 | kfree(chip->pwms); |
| 82 | chip->pwms = NULL; |
| 83 | } |
| 84 | |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 85 | static struct pwm_chip *pwmchip_find_by_name(const char *name) |
| 86 | { |
| 87 | struct pwm_chip *chip; |
| 88 | |
| 89 | if (!name) |
| 90 | return NULL; |
| 91 | |
| 92 | mutex_lock(&pwm_lock); |
| 93 | |
| 94 | list_for_each_entry(chip, &pwm_chips, list) { |
| 95 | const char *chip_name = dev_name(chip->dev); |
| 96 | |
| 97 | if (chip_name && strcmp(chip_name, name) == 0) { |
| 98 | mutex_unlock(&pwm_lock); |
| 99 | return chip; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | mutex_unlock(&pwm_lock); |
| 104 | |
| 105 | return NULL; |
| 106 | } |
| 107 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 108 | static int pwm_device_request(struct pwm_device *pwm, const char *label) |
| 109 | { |
| 110 | int err; |
| 111 | |
| 112 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| 113 | return -EBUSY; |
| 114 | |
| 115 | if (!try_module_get(pwm->chip->ops->owner)) |
| 116 | return -ENODEV; |
| 117 | |
| 118 | if (pwm->chip->ops->request) { |
| 119 | err = pwm->chip->ops->request(pwm->chip, pwm); |
| 120 | if (err) { |
| 121 | module_put(pwm->chip->ops->owner); |
| 122 | return err; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | set_bit(PWMF_REQUESTED, &pwm->flags); |
| 127 | pwm->label = label; |
| 128 | |
| 129 | return 0; |
| 130 | } |
| 131 | |
Thierry Reding | 7299ab7 | 2011-12-14 11:10:32 +0100 | [diff] [blame] | 132 | static struct pwm_device *of_pwm_simple_xlate(struct pwm_chip *pc, |
| 133 | const struct of_phandle_args *args) |
| 134 | { |
| 135 | struct pwm_device *pwm; |
| 136 | |
| 137 | if (pc->of_pwm_n_cells < 2) |
| 138 | return ERR_PTR(-EINVAL); |
| 139 | |
| 140 | if (args->args[0] >= pc->npwm) |
| 141 | return ERR_PTR(-EINVAL); |
| 142 | |
| 143 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); |
| 144 | if (IS_ERR(pwm)) |
| 145 | return pwm; |
| 146 | |
| 147 | pwm_set_period(pwm, args->args[1]); |
| 148 | |
| 149 | return pwm; |
| 150 | } |
| 151 | |
| 152 | void of_pwmchip_add(struct pwm_chip *chip) |
| 153 | { |
| 154 | if (!chip->dev || !chip->dev->of_node) |
| 155 | return; |
| 156 | |
| 157 | if (!chip->of_xlate) { |
| 158 | chip->of_xlate = of_pwm_simple_xlate; |
| 159 | chip->of_pwm_n_cells = 2; |
| 160 | } |
| 161 | |
| 162 | of_node_get(chip->dev->of_node); |
| 163 | } |
| 164 | |
| 165 | void of_pwmchip_remove(struct pwm_chip *chip) |
| 166 | { |
| 167 | if (chip->dev && chip->dev->of_node) |
| 168 | of_node_put(chip->dev->of_node); |
| 169 | } |
| 170 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 171 | /** |
| 172 | * pwm_set_chip_data() - set private chip data for a PWM |
| 173 | * @pwm: PWM device |
| 174 | * @data: pointer to chip-specific data |
| 175 | */ |
| 176 | int pwm_set_chip_data(struct pwm_device *pwm, void *data) |
| 177 | { |
| 178 | if (!pwm) |
| 179 | return -EINVAL; |
| 180 | |
| 181 | pwm->chip_data = data; |
| 182 | |
| 183 | return 0; |
| 184 | } |
| 185 | |
| 186 | /** |
| 187 | * pwm_get_chip_data() - get private chip data for a PWM |
| 188 | * @pwm: PWM device |
| 189 | */ |
| 190 | void *pwm_get_chip_data(struct pwm_device *pwm) |
| 191 | { |
| 192 | return pwm ? pwm->chip_data : NULL; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 193 | } |
| 194 | |
| 195 | /** |
| 196 | * pwmchip_add() - register a new PWM chip |
| 197 | * @chip: the PWM chip to add |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 198 | * |
| 199 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base |
| 200 | * will be used. |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 201 | */ |
| 202 | int pwmchip_add(struct pwm_chip *chip) |
| 203 | { |
| 204 | struct pwm_device *pwm; |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 205 | unsigned int i; |
| 206 | int ret; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 207 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 208 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
| 209 | !chip->ops->enable || !chip->ops->disable) |
| 210 | return -EINVAL; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 211 | |
| 212 | mutex_lock(&pwm_lock); |
| 213 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 214 | ret = alloc_pwms(chip->base, chip->npwm); |
| 215 | if (ret < 0) |
| 216 | goto out; |
| 217 | |
| 218 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); |
| 219 | if (!chip->pwms) { |
| 220 | ret = -ENOMEM; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 221 | goto out; |
| 222 | } |
| 223 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 224 | chip->base = ret; |
| 225 | |
| 226 | for (i = 0; i < chip->npwm; i++) { |
| 227 | pwm = &chip->pwms[i]; |
| 228 | |
| 229 | pwm->chip = chip; |
| 230 | pwm->pwm = chip->base + i; |
| 231 | pwm->hwpwm = i; |
| 232 | |
| 233 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
| 234 | } |
| 235 | |
| 236 | bitmap_set(allocated_pwms, chip->base, chip->npwm); |
| 237 | |
| 238 | INIT_LIST_HEAD(&chip->list); |
| 239 | list_add(&chip->list, &pwm_chips); |
| 240 | |
| 241 | ret = 0; |
| 242 | |
Thierry Reding | 7299ab7 | 2011-12-14 11:10:32 +0100 | [diff] [blame] | 243 | if (IS_ENABLED(CONFIG_OF)) |
| 244 | of_pwmchip_add(chip); |
| 245 | |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 246 | out: |
| 247 | mutex_unlock(&pwm_lock); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 248 | return ret; |
| 249 | } |
| 250 | EXPORT_SYMBOL_GPL(pwmchip_add); |
| 251 | |
| 252 | /** |
| 253 | * pwmchip_remove() - remove a PWM chip |
| 254 | * @chip: the PWM chip to remove |
| 255 | * |
| 256 | * Removes a PWM chip. This function may return busy if the PWM chip provides |
| 257 | * a PWM device that is still requested. |
| 258 | */ |
| 259 | int pwmchip_remove(struct pwm_chip *chip) |
| 260 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 261 | unsigned int i; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 262 | int ret = 0; |
| 263 | |
| 264 | mutex_lock(&pwm_lock); |
| 265 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 266 | for (i = 0; i < chip->npwm; i++) { |
| 267 | struct pwm_device *pwm = &chip->pwms[i]; |
| 268 | |
| 269 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
| 270 | ret = -EBUSY; |
| 271 | goto out; |
| 272 | } |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 273 | } |
| 274 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 275 | list_del_init(&chip->list); |
Thierry Reding | 7299ab7 | 2011-12-14 11:10:32 +0100 | [diff] [blame] | 276 | |
| 277 | if (IS_ENABLED(CONFIG_OF)) |
| 278 | of_pwmchip_remove(chip); |
| 279 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 280 | free_pwms(chip); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 281 | |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 282 | out: |
| 283 | mutex_unlock(&pwm_lock); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 284 | return ret; |
| 285 | } |
| 286 | EXPORT_SYMBOL_GPL(pwmchip_remove); |
| 287 | |
| 288 | /** |
| 289 | * pwm_request() - request a PWM device |
| 290 | * @pwm_id: global PWM device index |
| 291 | * @label: PWM device label |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 292 | * |
| 293 | * This function is deprecated, use pwm_get() instead. |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 294 | */ |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 295 | struct pwm_device *pwm_request(int pwm, const char *label) |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 296 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 297 | struct pwm_device *dev; |
| 298 | int err; |
| 299 | |
| 300 | if (pwm < 0 || pwm >= MAX_PWMS) |
| 301 | return ERR_PTR(-EINVAL); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 302 | |
| 303 | mutex_lock(&pwm_lock); |
| 304 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 305 | dev = pwm_to_device(pwm); |
| 306 | if (!dev) { |
| 307 | dev = ERR_PTR(-EPROBE_DEFER); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 308 | goto out; |
| 309 | } |
| 310 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 311 | err = pwm_device_request(dev, label); |
| 312 | if (err < 0) |
| 313 | dev = ERR_PTR(err); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 314 | |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 315 | out: |
| 316 | mutex_unlock(&pwm_lock); |
| 317 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 318 | return dev; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 319 | } |
| 320 | EXPORT_SYMBOL_GPL(pwm_request); |
| 321 | |
| 322 | /** |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 323 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip |
| 324 | * @chip: PWM chip |
| 325 | * @index: per-chip index of the PWM to request |
| 326 | * @label: a literal description string of this PWM |
| 327 | * |
| 328 | * Returns the PWM at the given index of the given PWM chip. A negative error |
| 329 | * code is returned if the index is not valid for the specified PWM chip or |
| 330 | * if the PWM device cannot be requested. |
| 331 | */ |
| 332 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, |
| 333 | unsigned int index, |
| 334 | const char *label) |
| 335 | { |
| 336 | struct pwm_device *pwm; |
| 337 | int err; |
| 338 | |
| 339 | if (!chip || index >= chip->npwm) |
| 340 | return ERR_PTR(-EINVAL); |
| 341 | |
| 342 | mutex_lock(&pwm_lock); |
| 343 | pwm = &chip->pwms[index]; |
| 344 | |
| 345 | err = pwm_device_request(pwm, label); |
| 346 | if (err < 0) |
| 347 | pwm = ERR_PTR(err); |
| 348 | |
| 349 | mutex_unlock(&pwm_lock); |
| 350 | return pwm; |
| 351 | } |
| 352 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
| 353 | |
| 354 | /** |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 355 | * pwm_free() - free a PWM device |
| 356 | * @pwm: PWM device |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 357 | * |
| 358 | * This function is deprecated, use pwm_put() instead. |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 359 | */ |
| 360 | void pwm_free(struct pwm_device *pwm) |
| 361 | { |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 362 | pwm_put(pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 363 | } |
| 364 | EXPORT_SYMBOL_GPL(pwm_free); |
| 365 | |
| 366 | /** |
| 367 | * pwm_config() - change a PWM device configuration |
| 368 | * @pwm: PWM device |
| 369 | * @duty_ns: "on" time (in nanoseconds) |
| 370 | * @period_ns: duration (in nanoseconds) of one cycle |
| 371 | */ |
| 372 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) |
| 373 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 374 | if (!pwm || period_ns == 0 || duty_ns > period_ns) |
| 375 | return -EINVAL; |
| 376 | |
| 377 | return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 378 | } |
| 379 | EXPORT_SYMBOL_GPL(pwm_config); |
| 380 | |
| 381 | /** |
| 382 | * pwm_enable() - start a PWM output toggling |
| 383 | * @pwm: PWM device |
| 384 | */ |
| 385 | int pwm_enable(struct pwm_device *pwm) |
| 386 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 387 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
| 388 | return pwm->chip->ops->enable(pwm->chip, pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 389 | |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 390 | return pwm ? 0 : -EINVAL; |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 391 | } |
| 392 | EXPORT_SYMBOL_GPL(pwm_enable); |
| 393 | |
| 394 | /** |
| 395 | * pwm_disable() - stop a PWM output toggling |
| 396 | * @pwm: PWM device |
| 397 | */ |
| 398 | void pwm_disable(struct pwm_device *pwm) |
| 399 | { |
Thierry Reding | f051c46 | 2011-12-14 11:12:23 +0100 | [diff] [blame] | 400 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
| 401 | pwm->chip->ops->disable(pwm->chip, pwm); |
Sascha Hauer | 0c2498f | 2011-01-28 09:40:40 +0100 | [diff] [blame] | 402 | } |
| 403 | EXPORT_SYMBOL_GPL(pwm_disable); |
Thierry Reding | 62099ab | 2012-03-26 09:31:48 +0200 | [diff] [blame] | 404 | |
Thierry Reding | 7299ab7 | 2011-12-14 11:10:32 +0100 | [diff] [blame] | 405 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
| 406 | { |
| 407 | struct pwm_chip *chip; |
| 408 | |
| 409 | mutex_lock(&pwm_lock); |
| 410 | |
| 411 | list_for_each_entry(chip, &pwm_chips, list) |
| 412 | if (chip->dev && chip->dev->of_node == np) { |
| 413 | mutex_unlock(&pwm_lock); |
| 414 | return chip; |
| 415 | } |
| 416 | |
| 417 | mutex_unlock(&pwm_lock); |
| 418 | |
| 419 | return ERR_PTR(-EPROBE_DEFER); |
| 420 | } |
| 421 | |
| 422 | /** |
| 423 | * of_pwm_request() - request a PWM via the PWM framework |
| 424 | * @np: device node to get the PWM from |
| 425 | * @con_id: consumer name |
| 426 | * |
| 427 | * Returns the PWM device parsed from the phandle and index specified in the |
| 428 | * "pwms" property of a device tree node or a negative error-code on failure. |
| 429 | * Values parsed from the device tree are stored in the returned PWM device |
| 430 | * object. |
| 431 | * |
| 432 | * If con_id is NULL, the first PWM device listed in the "pwms" property will |
| 433 | * be requested. Otherwise the "pwm-names" property is used to do a reverse |
| 434 | * lookup of the PWM index. This also means that the "pwm-names" property |
| 435 | * becomes mandatory for devices that look up the PWM device via the con_id |
| 436 | * parameter. |
| 437 | */ |
| 438 | static struct pwm_device *of_pwm_request(struct device_node *np, |
| 439 | const char *con_id) |
| 440 | { |
| 441 | struct pwm_device *pwm = NULL; |
| 442 | struct of_phandle_args args; |
| 443 | struct pwm_chip *pc; |
| 444 | int index = 0; |
| 445 | int err; |
| 446 | |
| 447 | if (con_id) { |
| 448 | index = of_property_match_string(np, "pwm-names", con_id); |
| 449 | if (index < 0) |
| 450 | return ERR_PTR(index); |
| 451 | } |
| 452 | |
| 453 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, |
| 454 | &args); |
| 455 | if (err) { |
| 456 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); |
| 457 | return ERR_PTR(err); |
| 458 | } |
| 459 | |
| 460 | pc = of_node_to_pwmchip(args.np); |
| 461 | if (IS_ERR(pc)) { |
| 462 | pr_debug("%s(): PWM chip not found\n", __func__); |
| 463 | pwm = ERR_CAST(pc); |
| 464 | goto put; |
| 465 | } |
| 466 | |
| 467 | if (args.args_count != pc->of_pwm_n_cells) { |
| 468 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, |
| 469 | args.np->full_name); |
| 470 | pwm = ERR_PTR(-EINVAL); |
| 471 | goto put; |
| 472 | } |
| 473 | |
| 474 | pwm = pc->of_xlate(pc, &args); |
| 475 | if (IS_ERR(pwm)) |
| 476 | goto put; |
| 477 | |
| 478 | /* |
| 479 | * If a consumer name was not given, try to look it up from the |
| 480 | * "pwm-names" property if it exists. Otherwise use the name of |
| 481 | * the user device node. |
| 482 | */ |
| 483 | if (!con_id) { |
| 484 | err = of_property_read_string_index(np, "pwm-names", index, |
| 485 | &con_id); |
| 486 | if (err < 0) |
| 487 | con_id = np->name; |
| 488 | } |
| 489 | |
| 490 | pwm->label = con_id; |
| 491 | |
| 492 | put: |
| 493 | of_node_put(args.np); |
| 494 | |
| 495 | return pwm; |
| 496 | } |
| 497 | |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 498 | /** |
| 499 | * pwm_add_table() - register PWM device consumers |
| 500 | * @table: array of consumers to register |
| 501 | * @num: number of consumers in table |
| 502 | */ |
| 503 | void __init pwm_add_table(struct pwm_lookup *table, size_t num) |
| 504 | { |
| 505 | mutex_lock(&pwm_lookup_lock); |
| 506 | |
| 507 | while (num--) { |
| 508 | list_add_tail(&table->list, &pwm_lookup_list); |
| 509 | table++; |
| 510 | } |
| 511 | |
| 512 | mutex_unlock(&pwm_lookup_lock); |
| 513 | } |
| 514 | |
| 515 | /** |
| 516 | * pwm_get() - look up and request a PWM device |
| 517 | * @dev: device for PWM consumer |
| 518 | * @con_id: consumer name |
| 519 | * |
Thierry Reding | 7299ab7 | 2011-12-14 11:10:32 +0100 | [diff] [blame] | 520 | * Lookup is first attempted using DT. If the device was not instantiated from |
| 521 | * a device tree, a PWM chip and a relative index is looked up via a table |
| 522 | * supplied by board setup code (see pwm_add_table()). |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 523 | * |
| 524 | * Once a PWM chip has been found the specified PWM device will be requested |
| 525 | * and is ready to be used. |
| 526 | */ |
| 527 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) |
| 528 | { |
| 529 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); |
| 530 | const char *dev_id = dev ? dev_name(dev): NULL; |
| 531 | struct pwm_chip *chip = NULL; |
Thierry Reding | d295b12 | 2012-07-11 08:05:05 +0200 | [diff] [blame] | 532 | unsigned int index = 0; |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 533 | unsigned int best = 0; |
| 534 | struct pwm_lookup *p; |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 535 | unsigned int match; |
| 536 | |
Thierry Reding | 7299ab7 | 2011-12-14 11:10:32 +0100 | [diff] [blame] | 537 | /* look up via DT first */ |
| 538 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) |
| 539 | return of_pwm_request(dev->of_node, con_id); |
| 540 | |
Thierry Reding | 8138d2d | 2012-03-26 08:42:48 +0200 | [diff] [blame] | 541 | /* |
| 542 | * We look up the provider in the static table typically provided by |
| 543 | * board setup code. We first try to lookup the consumer device by |
| 544 | * name. If the consumer device was passed in as NULL or if no match |
| 545 | * was found, we try to find the consumer by directly looking it up |
| 546 | * by name. |
| 547 | * |
| 548 | * If a match is found, the provider PWM chip is looked up by name |
| 549 | * and a PWM device is requested using the PWM device per-chip index. |
| 550 | * |
| 551 | * The lookup algorithm was shamelessly taken from the clock |
| 552 | * framework: |
| 553 | * |
| 554 | * We do slightly fuzzy matching here: |
| 555 | * An entry with a NULL ID is assumed to be a wildcard. |
| 556 | * If an entry has a device ID, it must match |
| 557 | * If an entry has a connection ID, it must match |
| 558 | * Then we take the most specific entry - with the following order |
| 559 | * of precedence: dev+con > dev only > con only. |
| 560 | */ |
| 561 | mutex_lock(&pwm_lookup_lock); |
| 562 | |
| 563 | list_for_each_entry(p, &pwm_lookup_list, list) { |
| 564 | match = 0; |
| 565 | |
| 566 | if (p->dev_id) { |
| 567 | if (!dev_id || strcmp(p->dev_id, dev_id)) |
| 568 | continue; |
| 569 | |
| 570 | match += 2; |
| 571 | } |
| 572 | |
| 573 | if (p->con_id) { |
| 574 | if (!con_id || strcmp(p->con_id, con_id)) |
| 575 | continue; |
| 576 | |
| 577 | match += 1; |
| 578 | } |
| 579 | |
| 580 | if (match > best) { |
| 581 | chip = pwmchip_find_by_name(p->provider); |
| 582 | index = p->index; |
| 583 | |
| 584 | if (match != 3) |
| 585 | best = match; |
| 586 | else |
| 587 | break; |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | if (chip) |
| 592 | pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id); |
| 593 | |
| 594 | mutex_unlock(&pwm_lookup_lock); |
| 595 | |
| 596 | return pwm; |
| 597 | } |
| 598 | EXPORT_SYMBOL_GPL(pwm_get); |
| 599 | |
| 600 | /** |
| 601 | * pwm_put() - release a PWM device |
| 602 | * @pwm: PWM device |
| 603 | */ |
| 604 | void pwm_put(struct pwm_device *pwm) |
| 605 | { |
| 606 | if (!pwm) |
| 607 | return; |
| 608 | |
| 609 | mutex_lock(&pwm_lock); |
| 610 | |
| 611 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { |
| 612 | pr_warning("PWM device already freed\n"); |
| 613 | goto out; |
| 614 | } |
| 615 | |
| 616 | if (pwm->chip->ops->free) |
| 617 | pwm->chip->ops->free(pwm->chip, pwm); |
| 618 | |
| 619 | pwm->label = NULL; |
| 620 | |
| 621 | module_put(pwm->chip->ops->owner); |
| 622 | out: |
| 623 | mutex_unlock(&pwm_lock); |
| 624 | } |
| 625 | EXPORT_SYMBOL_GPL(pwm_put); |
| 626 | |
Thierry Reding | 62099ab | 2012-03-26 09:31:48 +0200 | [diff] [blame] | 627 | #ifdef CONFIG_DEBUG_FS |
| 628 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) |
| 629 | { |
| 630 | unsigned int i; |
| 631 | |
| 632 | for (i = 0; i < chip->npwm; i++) { |
| 633 | struct pwm_device *pwm = &chip->pwms[i]; |
| 634 | |
| 635 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); |
| 636 | |
| 637 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| 638 | seq_printf(s, " requested"); |
| 639 | |
| 640 | if (test_bit(PWMF_ENABLED, &pwm->flags)) |
| 641 | seq_printf(s, " enabled"); |
| 642 | |
| 643 | seq_printf(s, "\n"); |
| 644 | } |
| 645 | } |
| 646 | |
| 647 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) |
| 648 | { |
| 649 | mutex_lock(&pwm_lock); |
| 650 | s->private = ""; |
| 651 | |
| 652 | return seq_list_start(&pwm_chips, *pos); |
| 653 | } |
| 654 | |
| 655 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) |
| 656 | { |
| 657 | s->private = "\n"; |
| 658 | |
| 659 | return seq_list_next(v, &pwm_chips, pos); |
| 660 | } |
| 661 | |
| 662 | static void pwm_seq_stop(struct seq_file *s, void *v) |
| 663 | { |
| 664 | mutex_unlock(&pwm_lock); |
| 665 | } |
| 666 | |
| 667 | static int pwm_seq_show(struct seq_file *s, void *v) |
| 668 | { |
| 669 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); |
| 670 | |
| 671 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, |
| 672 | chip->dev->bus ? chip->dev->bus->name : "no-bus", |
| 673 | dev_name(chip->dev), chip->npwm, |
| 674 | (chip->npwm != 1) ? "s" : ""); |
| 675 | |
| 676 | if (chip->ops->dbg_show) |
| 677 | chip->ops->dbg_show(chip, s); |
| 678 | else |
| 679 | pwm_dbg_show(chip, s); |
| 680 | |
| 681 | return 0; |
| 682 | } |
| 683 | |
| 684 | static const struct seq_operations pwm_seq_ops = { |
| 685 | .start = pwm_seq_start, |
| 686 | .next = pwm_seq_next, |
| 687 | .stop = pwm_seq_stop, |
| 688 | .show = pwm_seq_show, |
| 689 | }; |
| 690 | |
| 691 | static int pwm_seq_open(struct inode *inode, struct file *file) |
| 692 | { |
| 693 | return seq_open(file, &pwm_seq_ops); |
| 694 | } |
| 695 | |
| 696 | static const struct file_operations pwm_debugfs_ops = { |
| 697 | .owner = THIS_MODULE, |
| 698 | .open = pwm_seq_open, |
| 699 | .read = seq_read, |
| 700 | .llseek = seq_lseek, |
| 701 | .release = seq_release, |
| 702 | }; |
| 703 | |
| 704 | static int __init pwm_debugfs_init(void) |
| 705 | { |
| 706 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, |
| 707 | &pwm_debugfs_ops); |
| 708 | |
| 709 | return 0; |
| 710 | } |
| 711 | |
| 712 | subsys_initcall(pwm_debugfs_init); |
| 713 | #endif /* CONFIG_DEBUG_FS */ |