1 #ifndef __LINUX_PWM_H 2 #define __LINUX_PWM_H 3 4 #include <linux/err.h> 5 #include <linux/of.h> 6 7 struct pwm_device; 8 struct seq_file; 9 10 #if IS_ENABLED(CONFIG_PWM) 11 /* 12 * pwm_request - request a PWM device 13 */ 14 struct pwm_device *pwm_request(int pwm_id, const char *label); 15 16 /* 17 * pwm_free - free a PWM device 18 */ 19 void pwm_free(struct pwm_device *pwm); 20 21 /* 22 * pwm_config - change a PWM device configuration 23 */ 24 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns); 25 26 /* 27 * pwm_enable - start a PWM output toggling 28 */ 29 int pwm_enable(struct pwm_device *pwm); 30 31 /* 32 * pwm_disable - stop a PWM output toggling 33 */ 34 void pwm_disable(struct pwm_device *pwm); 35 #else 36 static inline struct pwm_device *pwm_request(int pwm_id, const char *label) 37 { 38 return ERR_PTR(-ENODEV); 39 } 40 41 static inline void pwm_free(struct pwm_device *pwm) 42 { 43 } 44 45 static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) 46 { 47 return -EINVAL; 48 } 49 50 static inline int pwm_enable(struct pwm_device *pwm) 51 { 52 return -EINVAL; 53 } 54 55 static inline void pwm_disable(struct pwm_device *pwm) 56 { 57 } 58 #endif 59 60 struct pwm_chip; 61 62 /** 63 * enum pwm_polarity - polarity of a PWM signal 64 * @PWM_POLARITY_NORMAL: a high signal for the duration of the duty- 65 * cycle, followed by a low signal for the remainder of the pulse 66 * period 67 * @PWM_POLARITY_INVERSED: a low signal for the duration of the duty- 68 * cycle, followed by a high signal for the remainder of the pulse 69 * period 70 */ 71 enum pwm_polarity { 72 PWM_POLARITY_NORMAL, 73 PWM_POLARITY_INVERSED, 74 }; 75 76 enum { 77 PWMF_REQUESTED = 1 << 0, 78 PWMF_ENABLED = 1 << 1, 79 PWMF_EXPORTED = 1 << 2, 80 }; 81 82 /** 83 * struct pwm_device - PWM channel object 84 * @label: name of the PWM device 85 * @flags: flags associated with the PWM device 86 * @hwpwm: per-chip relative index of the PWM device 87 * @pwm: global index of the PWM device 88 * @chip: PWM chip providing this PWM device 89 * @chip_data: chip-private data associated with the PWM device 90 * @period: period of the PWM signal (in nanoseconds) 91 * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) 92 * @polarity: polarity of the PWM signal 93 */ 94 struct pwm_device { 95 const char *label; 96 unsigned long flags; 97 unsigned int hwpwm; 98 unsigned int pwm; 99 struct pwm_chip *chip; 100 void *chip_data; 101 102 unsigned int period; 103 unsigned int duty_cycle; 104 enum pwm_polarity polarity; 105 }; 106 107 static inline bool pwm_is_enabled(const struct pwm_device *pwm) 108 { 109 return test_bit(PWMF_ENABLED, &pwm->flags); 110 } 111 112 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) 113 { 114 if (pwm) 115 pwm->period = period; 116 } 117 118 static inline unsigned int pwm_get_period(const struct pwm_device *pwm) 119 { 120 return pwm ? pwm->period : 0; 121 } 122 123 static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) 124 { 125 if (pwm) 126 pwm->duty_cycle = duty; 127 } 128 129 static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm) 130 { 131 return pwm ? pwm->duty_cycle : 0; 132 } 133 134 /* 135 * pwm_set_polarity - configure the polarity of a PWM signal 136 */ 137 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity); 138 139 static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) 140 { 141 return pwm ? pwm->polarity : PWM_POLARITY_NORMAL; 142 } 143 144 /** 145 * struct pwm_ops - PWM controller operations 146 * @request: optional hook for requesting a PWM 147 * @free: optional hook for freeing a PWM 148 * @config: configure duty cycles and period length for this PWM 149 * @set_polarity: configure the polarity of this PWM 150 * @enable: enable PWM output toggling 151 * @disable: disable PWM output toggling 152 * @dbg_show: optional routine to show contents in debugfs 153 * @owner: helps prevent removal of modules exporting active PWMs 154 */ 155 struct pwm_ops { 156 int (*request)(struct pwm_chip *chip, struct pwm_device *pwm); 157 void (*free)(struct pwm_chip *chip, struct pwm_device *pwm); 158 int (*config)(struct pwm_chip *chip, struct pwm_device *pwm, 159 int duty_ns, int period_ns); 160 int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm, 161 enum pwm_polarity polarity); 162 int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm); 163 void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); 164 #ifdef CONFIG_DEBUG_FS 165 void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s); 166 #endif 167 struct module *owner; 168 }; 169 170 /** 171 * struct pwm_chip - abstract a PWM controller 172 * @dev: device providing the PWMs 173 * @list: list node for internal use 174 * @ops: callbacks for this PWM controller 175 * @base: number of first PWM controlled by this chip 176 * @npwm: number of PWMs controlled by this chip 177 * @pwms: array of PWM devices allocated by the framework 178 * @of_xlate: request a PWM device given a device tree PWM specifier 179 * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier 180 * @can_sleep: must be true if the .config(), .enable() or .disable() 181 * operations may sleep 182 */ 183 struct pwm_chip { 184 struct device *dev; 185 struct list_head list; 186 const struct pwm_ops *ops; 187 int base; 188 unsigned int npwm; 189 190 struct pwm_device *pwms; 191 192 struct pwm_device * (*of_xlate)(struct pwm_chip *pc, 193 const struct of_phandle_args *args); 194 unsigned int of_pwm_n_cells; 195 bool can_sleep; 196 }; 197 198 #if IS_ENABLED(CONFIG_PWM) 199 int pwm_set_chip_data(struct pwm_device *pwm, void *data); 200 void *pwm_get_chip_data(struct pwm_device *pwm); 201 202 int pwmchip_add_with_polarity(struct pwm_chip *chip, 203 enum pwm_polarity polarity); 204 int pwmchip_add(struct pwm_chip *chip); 205 int pwmchip_remove(struct pwm_chip *chip); 206 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 207 unsigned int index, 208 const char *label); 209 210 struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, 211 const struct of_phandle_args *args); 212 213 struct pwm_device *pwm_get(struct device *dev, const char *con_id); 214 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id); 215 void pwm_put(struct pwm_device *pwm); 216 217 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id); 218 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, 219 const char *con_id); 220 void devm_pwm_put(struct device *dev, struct pwm_device *pwm); 221 222 bool pwm_can_sleep(struct pwm_device *pwm); 223 #else 224 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data) 225 { 226 return -EINVAL; 227 } 228 229 static inline void *pwm_get_chip_data(struct pwm_device *pwm) 230 { 231 return NULL; 232 } 233 234 static inline int pwmchip_add(struct pwm_chip *chip) 235 { 236 return -EINVAL; 237 } 238 239 static inline int pwmchip_add_inversed(struct pwm_chip *chip) 240 { 241 return -EINVAL; 242 } 243 244 static inline int pwmchip_remove(struct pwm_chip *chip) 245 { 246 return -EINVAL; 247 } 248 249 static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 250 unsigned int index, 251 const char *label) 252 { 253 return ERR_PTR(-ENODEV); 254 } 255 256 static inline struct pwm_device *pwm_get(struct device *dev, 257 const char *consumer) 258 { 259 return ERR_PTR(-ENODEV); 260 } 261 262 static inline struct pwm_device *of_pwm_get(struct device_node *np, 263 const char *con_id) 264 { 265 return ERR_PTR(-ENODEV); 266 } 267 268 static inline void pwm_put(struct pwm_device *pwm) 269 { 270 } 271 272 static inline struct pwm_device *devm_pwm_get(struct device *dev, 273 const char *consumer) 274 { 275 return ERR_PTR(-ENODEV); 276 } 277 278 static inline struct pwm_device *devm_of_pwm_get(struct device *dev, 279 struct device_node *np, 280 const char *con_id) 281 { 282 return ERR_PTR(-ENODEV); 283 } 284 285 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm) 286 { 287 } 288 289 static inline bool pwm_can_sleep(struct pwm_device *pwm) 290 { 291 return false; 292 } 293 #endif 294 295 struct pwm_lookup { 296 struct list_head list; 297 const char *provider; 298 unsigned int index; 299 const char *dev_id; 300 const char *con_id; 301 unsigned int period; 302 enum pwm_polarity polarity; 303 }; 304 305 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id, _period, _polarity) \ 306 { \ 307 .provider = _provider, \ 308 .index = _index, \ 309 .dev_id = _dev_id, \ 310 .con_id = _con_id, \ 311 .period = _period, \ 312 .polarity = _polarity \ 313 } 314 315 #if IS_ENABLED(CONFIG_PWM) 316 void pwm_add_table(struct pwm_lookup *table, size_t num); 317 void pwm_remove_table(struct pwm_lookup *table, size_t num); 318 #else 319 static inline void pwm_add_table(struct pwm_lookup *table, size_t num) 320 { 321 } 322 323 static inline void pwm_remove_table(struct pwm_lookup *table, size_t num) 324 { 325 } 326 #endif 327 328 #ifdef CONFIG_PWM_SYSFS 329 void pwmchip_sysfs_export(struct pwm_chip *chip); 330 void pwmchip_sysfs_unexport(struct pwm_chip *chip); 331 #else 332 static inline void pwmchip_sysfs_export(struct pwm_chip *chip) 333 { 334 } 335 336 static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip) 337 { 338 } 339 #endif /* CONFIG_PWM_SYSFS */ 340 341 #endif /* __LINUX_PWM_H */ 342