1 #ifndef __LINUX_PWM_H 2 #define __LINUX_PWM_H 3 4 #include <linux/err.h> 5 #include <linux/mutex.h> 6 #include <linux/of.h> 7 8 struct pwm_device; 9 struct seq_file; 10 11 #if IS_ENABLED(CONFIG_PWM) 12 /* 13 * pwm_request - request a PWM device 14 */ 15 struct pwm_device *pwm_request(int pwm_id, const char *label); 16 17 /* 18 * pwm_free - free a PWM device 19 */ 20 void pwm_free(struct pwm_device *pwm); 21 22 /* 23 * pwm_config - change a PWM device configuration 24 */ 25 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns); 26 27 /* 28 * pwm_enable - start a PWM output toggling 29 */ 30 int pwm_enable(struct pwm_device *pwm); 31 32 /* 33 * pwm_disable - stop a PWM output toggling 34 */ 35 void pwm_disable(struct pwm_device *pwm); 36 #else 37 static inline struct pwm_device *pwm_request(int pwm_id, const char *label) 38 { 39 return ERR_PTR(-ENODEV); 40 } 41 42 static inline void pwm_free(struct pwm_device *pwm) 43 { 44 } 45 46 static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) 47 { 48 return -EINVAL; 49 } 50 51 static inline int pwm_enable(struct pwm_device *pwm) 52 { 53 return -EINVAL; 54 } 55 56 static inline void pwm_disable(struct pwm_device *pwm) 57 { 58 } 59 #endif 60 61 struct pwm_chip; 62 63 /** 64 * enum pwm_polarity - polarity of a PWM signal 65 * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty- 66 * cycle, followed by a low signal for the remainder of the pulse 67 * period 68 * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty- 69 * cycle, followed by a high signal for the remainder of the pulse 70 * period 71 */ 72 enum pwm_polarity { 73 PWM_POLARITY_NORMAL, 74 PWM_POLARITY_INVERSED, 75 }; 76 77 /** 78 * struct pwm_args - board-dependent PWM arguments 79 * @period: reference period 80 * @polarity: reference polarity 81 * 82 * This structure describes board-dependent arguments attached to a PWM 83 * device. These arguments are usually retrieved from the PWM lookup table or 84 * device tree. 85 * 86 * Do not confuse this with the PWM state: PWM arguments represent the initial 87 * configuration that users want to use on this PWM device rather than the 88 * current PWM hardware state. 89 */ 90 struct pwm_args { 91 unsigned int period; 92 enum pwm_polarity polarity; 93 }; 94 95 enum { 96 PWMF_REQUESTED = 1 << 0, 97 PWMF_ENABLED = 1 << 1, 98 PWMF_EXPORTED = 1 << 2, 99 }; 100 101 /** 102 * struct pwm_device - PWM channel object 103 * @label: name of the PWM device 104 * @flags: flags associated with the PWM device 105 * @hwpwm: per-chip relative index of the PWM device 106 * @pwm: global index of the PWM device 107 * @chip: PWM chip providing this PWM device 108 * @chip_data: chip-private data associated with the PWM device 109 * @lock: used to serialize accesses to the PWM device where necessary 110 * @period: period of the PWM signal (in nanoseconds) 111 * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) 112 * @polarity: polarity of the PWM signal 113 * @args: PWM arguments 114 */ 115 struct pwm_device { 116 const char *label; 117 unsigned long flags; 118 unsigned int hwpwm; 119 unsigned int pwm; 120 struct pwm_chip *chip; 121 void *chip_data; 122 struct mutex lock; 123 124 unsigned int period; 125 unsigned int duty_cycle; 126 enum pwm_polarity polarity; 127 128 struct pwm_args args; 129 }; 130 131 static inline bool pwm_is_enabled(const struct pwm_device *pwm) 132 { 133 return test_bit(PWMF_ENABLED, &pwm->flags); 134 } 135 136 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) 137 { 138 if (pwm) 139 pwm->period = period; 140 } 141 142 static inline unsigned int pwm_get_period(const struct pwm_device *pwm) 143 { 144 return pwm ? pwm->period : 0; 145 } 146 147 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) 148 { 149 if (pwm) 150 pwm->duty_cycle = duty; 151 } 152 153 static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm) 154 { 155 return pwm ? pwm->duty_cycle : 0; 156 } 157 158 /* 159 * pwm_set_polarity - configure the polarity of a PWM signal 160 */ 161 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity); 162 163 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) 164 { 165 return pwm ? pwm->polarity : PWM_POLARITY_NORMAL; 166 } 167 168 static inline void pwm_get_args(const struct pwm_device *pwm, 169 struct pwm_args *args) 170 { 171 *args = pwm->args; 172 } 173 174 static inline void pwm_apply_args(struct pwm_device *pwm) 175 { 176 pwm_set_period(pwm, pwm->args.period); 177 pwm_set_polarity(pwm, pwm->args.polarity); 178 } 179 180 /** 181 * struct pwm_ops - PWM controller operations 182 * @request: optional hook for requesting a PWM 183 * @free: optional hook for freeing a PWM 184 * @config: configure duty cycles and period length for this PWM 185 * @set_polarity: configure the polarity of this PWM 186 * @enable: enable PWM output toggling 187 * @disable: disable PWM output toggling 188 * @dbg_show: optional routine to show contents in debugfs 189 * @owner: helps prevent removal of modules exporting active PWMs 190 */ 191 struct pwm_ops { 192 int (*request)(struct pwm_chip *chip, struct pwm_device *pwm); 193 void (*free)(struct pwm_chip *chip, struct pwm_device *pwm); 194 int (*config)(struct pwm_chip *chip, struct pwm_device *pwm, 195 int duty_ns, int period_ns); 196 int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm, 197 enum pwm_polarity polarity); 198 int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm); 199 void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); 200 #ifdef CONFIG_DEBUG_FS 201 void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s); 202 #endif 203 struct module *owner; 204 }; 205 206 /** 207 * struct pwm_chip - abstract a PWM controller 208 * @dev: device providing the PWMs 209 * @list: list node for internal use 210 * @ops: callbacks for this PWM controller 211 * @base: number of first PWM controlled by this chip 212 * @npwm: number of PWMs controlled by this chip 213 * @pwms: array of PWM devices allocated by the framework 214 * @of_xlate: request a PWM device given a device tree PWM specifier 215 * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier 216 * @can_sleep: must be true if the .config(), .enable() or .disable() 217 * operations may sleep 218 */ 219 struct pwm_chip { 220 struct device *dev; 221 struct list_head list; 222 const struct pwm_ops *ops; 223 int base; 224 unsigned int npwm; 225 226 struct pwm_device *pwms; 227 228 struct pwm_device * (*of_xlate)(struct pwm_chip *pc, 229 const struct of_phandle_args *args); 230 unsigned int of_pwm_n_cells; 231 bool can_sleep; 232 }; 233 234 #if IS_ENABLED(CONFIG_PWM) 235 int pwm_set_chip_data(struct pwm_device *pwm, void *data); 236 void *pwm_get_chip_data(struct pwm_device *pwm); 237 238 int pwmchip_add_with_polarity(struct pwm_chip *chip, 239 enum pwm_polarity polarity); 240 int pwmchip_add(struct pwm_chip *chip); 241 int pwmchip_remove(struct pwm_chip *chip); 242 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 243 unsigned int index, 244 const char *label); 245 246 struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, 247 const struct of_phandle_args *args); 248 249 struct pwm_device *pwm_get(struct device *dev, const char *con_id); 250 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id); 251 void pwm_put(struct pwm_device *pwm); 252 253 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id); 254 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, 255 const char *con_id); 256 void devm_pwm_put(struct device *dev, struct pwm_device *pwm); 257 258 bool pwm_can_sleep(struct pwm_device *pwm); 259 #else 260 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data) 261 { 262 return -EINVAL; 263 } 264 265 static inline void *pwm_get_chip_data(struct pwm_device *pwm) 266 { 267 return NULL; 268 } 269 270 static inline int pwmchip_add(struct pwm_chip *chip) 271 { 272 return -EINVAL; 273 } 274 275 static inline int pwmchip_add_inversed(struct pwm_chip *chip) 276 { 277 return -EINVAL; 278 } 279 280 static inline int pwmchip_remove(struct pwm_chip *chip) 281 { 282 return -EINVAL; 283 } 284 285 static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 286 unsigned int index, 287 const char *label) 288 { 289 return ERR_PTR(-ENODEV); 290 } 291 292 static inline struct pwm_device *pwm_get(struct device *dev, 293 const char *consumer) 294 { 295 return ERR_PTR(-ENODEV); 296 } 297 298 static inline struct pwm_device *of_pwm_get(struct device_node *np, 299 const char *con_id) 300 { 301 return ERR_PTR(-ENODEV); 302 } 303 304 static inline void pwm_put(struct pwm_device *pwm) 305 { 306 } 307 308 static inline struct pwm_device *devm_pwm_get(struct device *dev, 309 const char *consumer) 310 { 311 return ERR_PTR(-ENODEV); 312 } 313 314 static inline struct pwm_device *devm_of_pwm_get(struct device *dev, 315 struct device_node *np, 316 const char *con_id) 317 { 318 return ERR_PTR(-ENODEV); 319 } 320 321 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm) 322 { 323 } 324 325 static inline bool pwm_can_sleep(struct pwm_device *pwm) 326 { 327 return false; 328 } 329 #endif 330 331 struct pwm_lookup { 332 struct list_head list; 333 const char *provider; 334 unsigned int index; 335 const char *dev_id; 336 const char *con_id; 337 unsigned int period; 338 enum pwm_polarity polarity; 339 }; 340 341 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \ 342 { \ 343 .provider = _provider, \ 344 .index = _index, \ 345 .dev_id = _dev_id, \ 346 .con_id = _con_id, \ 347 .period = _period, \ 348 .polarity = _polarity \ 349 } 350 351 #if IS_ENABLED(CONFIG_PWM) 352 void pwm_add_table(struct pwm_lookup *table, size_t num); 353 void pwm_remove_table(struct pwm_lookup *table, size_t num); 354 #else 355 static inline void pwm_add_table(struct pwm_lookup *table, size_t num) 356 { 357 } 358 359 static inline void pwm_remove_table(struct pwm_lookup *table, size_t num) 360 { 361 } 362 #endif 363 364 #ifdef CONFIG_PWM_SYSFS 365 void pwmchip_sysfs_export(struct pwm_chip *chip); 366 void pwmchip_sysfs_unexport(struct pwm_chip *chip); 367 #else 368 static inline void pwmchip_sysfs_export(struct pwm_chip *chip) 369 { 370 } 371 372 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip) 373 { 374 } 375 #endif /* CONFIG_PWM_SYSFS */ 376 377 #endif /* __LINUX_PWM_H */ 378