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