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 enum { 78 PWMF_REQUESTED = 1 << 0, 79 PWMF_ENABLED = 1 << 1, 80 PWMF_EXPORTED = 1 << 2, 81 }; 82 83 /** 84 * struct pwm_device - PWM channel object 85 * @label: name of the PWM device 86 * @flags: flags associated with the PWM device 87 * @hwpwm: per-chip relative index of the PWM device 88 * @pwm: global index of the PWM device 89 * @chip: PWM chip providing this PWM device 90 * @chip_data: chip-private data associated with the PWM device 91 * @lock: used to serialize accesses to the PWM device where necessary 92 * @period: period of the PWM signal (in nanoseconds) 93 * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) 94 * @polarity: polarity of the PWM signal 95 */ 96 struct pwm_device { 97 const char *label; 98 unsigned long flags; 99 unsigned int hwpwm; 100 unsigned int pwm; 101 struct pwm_chip *chip; 102 void *chip_data; 103 struct mutex lock; 104 105 unsigned int period; 106 unsigned int duty_cycle; 107 enum pwm_polarity polarity; 108 }; 109 110 static inline bool pwm_is_enabled(const struct pwm_device *pwm) 111 { 112 return test_bit(PWMF_ENABLED, &pwm->flags); 113 } 114 115 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) 116 { 117 if (pwm) 118 pwm->period = period; 119 } 120 121 static inline unsigned int pwm_get_period(const struct pwm_device *pwm) 122 { 123 return pwm ? pwm->period : 0; 124 } 125 126 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) 127 { 128 if (pwm) 129 pwm->duty_cycle = duty; 130 } 131 132 static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm) 133 { 134 return pwm ? pwm->duty_cycle : 0; 135 } 136 137 /* 138 * pwm_set_polarity - configure the polarity of a PWM signal 139 */ 140 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity); 141 142 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) 143 { 144 return pwm ? pwm->polarity : PWM_POLARITY_NORMAL; 145 } 146 147 /** 148 * struct pwm_ops - PWM controller operations 149 * @request: optional hook for requesting a PWM 150 * @free: optional hook for freeing a PWM 151 * @config: configure duty cycles and period length for this PWM 152 * @set_polarity: configure the polarity of this PWM 153 * @enable: enable PWM output toggling 154 * @disable: disable PWM output toggling 155 * @dbg_show: optional routine to show contents in debugfs 156 * @owner: helps prevent removal of modules exporting active PWMs 157 */ 158 struct pwm_ops { 159 int (*request)(struct pwm_chip *chip, struct pwm_device *pwm); 160 void (*free)(struct pwm_chip *chip, struct pwm_device *pwm); 161 int (*config)(struct pwm_chip *chip, struct pwm_device *pwm, 162 int duty_ns, int period_ns); 163 int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm, 164 enum pwm_polarity polarity); 165 int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm); 166 void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); 167 #ifdef CONFIG_DEBUG_FS 168 void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s); 169 #endif 170 struct module *owner; 171 }; 172 173 /** 174 * struct pwm_chip - abstract a PWM controller 175 * @dev: device providing the PWMs 176 * @list: list node for internal use 177 * @ops: callbacks for this PWM controller 178 * @base: number of first PWM controlled by this chip 179 * @npwm: number of PWMs controlled by this chip 180 * @pwms: array of PWM devices allocated by the framework 181 * @of_xlate: request a PWM device given a device tree PWM specifier 182 * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier 183 * @can_sleep: must be true if the .config(), .enable() or .disable() 184 * operations may sleep 185 */ 186 struct pwm_chip { 187 struct device *dev; 188 struct list_head list; 189 const struct pwm_ops *ops; 190 int base; 191 unsigned int npwm; 192 193 struct pwm_device *pwms; 194 195 struct pwm_device * (*of_xlate)(struct pwm_chip *pc, 196 const struct of_phandle_args *args); 197 unsigned int of_pwm_n_cells; 198 bool can_sleep; 199 }; 200 201 #if IS_ENABLED(CONFIG_PWM) 202 int pwm_set_chip_data(struct pwm_device *pwm, void *data); 203 void *pwm_get_chip_data(struct pwm_device *pwm); 204 205 int pwmchip_add_with_polarity(struct pwm_chip *chip, 206 enum pwm_polarity polarity); 207 int pwmchip_add(struct pwm_chip *chip); 208 int pwmchip_remove(struct pwm_chip *chip); 209 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 210 unsigned int index, 211 const char *label); 212 213 struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, 214 const struct of_phandle_args *args); 215 216 struct pwm_device *pwm_get(struct device *dev, const char *con_id); 217 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id); 218 void pwm_put(struct pwm_device *pwm); 219 220 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id); 221 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, 222 const char *con_id); 223 void devm_pwm_put(struct device *dev, struct pwm_device *pwm); 224 225 bool pwm_can_sleep(struct pwm_device *pwm); 226 #else 227 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data) 228 { 229 return -EINVAL; 230 } 231 232 static inline void *pwm_get_chip_data(struct pwm_device *pwm) 233 { 234 return NULL; 235 } 236 237 static inline int pwmchip_add(struct pwm_chip *chip) 238 { 239 return -EINVAL; 240 } 241 242 static inline int pwmchip_add_inversed(struct pwm_chip *chip) 243 { 244 return -EINVAL; 245 } 246 247 static inline int pwmchip_remove(struct pwm_chip *chip) 248 { 249 return -EINVAL; 250 } 251 252 static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 253 unsigned int index, 254 const char *label) 255 { 256 return ERR_PTR(-ENODEV); 257 } 258 259 static inline struct pwm_device *pwm_get(struct device *dev, 260 const char *consumer) 261 { 262 return ERR_PTR(-ENODEV); 263 } 264 265 static inline struct pwm_device *of_pwm_get(struct device_node *np, 266 const char *con_id) 267 { 268 return ERR_PTR(-ENODEV); 269 } 270 271 static inline void pwm_put(struct pwm_device *pwm) 272 { 273 } 274 275 static inline struct pwm_device *devm_pwm_get(struct device *dev, 276 const char *consumer) 277 { 278 return ERR_PTR(-ENODEV); 279 } 280 281 static inline struct pwm_device *devm_of_pwm_get(struct device *dev, 282 struct device_node *np, 283 const char *con_id) 284 { 285 return ERR_PTR(-ENODEV); 286 } 287 288 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm) 289 { 290 } 291 292 static inline bool pwm_can_sleep(struct pwm_device *pwm) 293 { 294 return false; 295 } 296 #endif 297 298 struct pwm_lookup { 299 struct list_head list; 300 const char *provider; 301 unsigned int index; 302 const char *dev_id; 303 const char *con_id; 304 unsigned int period; 305 enum pwm_polarity polarity; 306 }; 307 308 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \ 309 { \ 310 .provider = _provider, \ 311 .index = _index, \ 312 .dev_id = _dev_id, \ 313 .con_id = _con_id, \ 314 .period = _period, \ 315 .polarity = _polarity \ 316 } 317 318 #if IS_ENABLED(CONFIG_PWM) 319 void pwm_add_table(struct pwm_lookup *table, size_t num); 320 void pwm_remove_table(struct pwm_lookup *table, size_t num); 321 #else 322 static inline void pwm_add_table(struct pwm_lookup *table, size_t num) 323 { 324 } 325 326 static inline void pwm_remove_table(struct pwm_lookup *table, size_t num) 327 { 328 } 329 #endif 330 331 #ifdef CONFIG_PWM_SYSFS 332 void pwmchip_sysfs_export(struct pwm_chip *chip); 333 void pwmchip_sysfs_unexport(struct pwm_chip *chip); 334 #else 335 static inline void pwmchip_sysfs_export(struct pwm_chip *chip) 336 { 337 } 338 339 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip) 340 { 341 } 342 #endif /* CONFIG_PWM_SYSFS */ 343 344 #endif /* __LINUX_PWM_H */ 345