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) || IS_ENABLED(CONFIG_HAVE_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 }; 80 81 struct pwm_device { 82 const char *label; 83 unsigned long flags; 84 unsigned int hwpwm; 85 unsigned int pwm; 86 struct pwm_chip *chip; 87 void *chip_data; 88 89 unsigned int period; /* in nanoseconds */ 90 }; 91 92 static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) 93 { 94 if (pwm) 95 pwm->period = period; 96 } 97 98 static inline unsigned int pwm_get_period(struct pwm_device *pwm) 99 { 100 return pwm ? pwm->period : 0; 101 } 102 103 /* 104 * pwm_set_polarity - configure the polarity of a PWM signal 105 */ 106 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity); 107 108 /** 109 * struct pwm_ops - PWM controller operations 110 * @request: optional hook for requesting a PWM 111 * @free: optional hook for freeing a PWM 112 * @config: configure duty cycles and period length for this PWM 113 * @set_polarity: configure the polarity of this PWM 114 * @enable: enable PWM output toggling 115 * @disable: disable PWM output toggling 116 * @dbg_show: optional routine to show contents in debugfs 117 * @owner: helps prevent removal of modules exporting active PWMs 118 */ 119 struct pwm_ops { 120 int (*request)(struct pwm_chip *chip, 121 struct pwm_device *pwm); 122 void (*free)(struct pwm_chip *chip, 123 struct pwm_device *pwm); 124 int (*config)(struct pwm_chip *chip, 125 struct pwm_device *pwm, 126 int duty_ns, int period_ns); 127 int (*set_polarity)(struct pwm_chip *chip, 128 struct pwm_device *pwm, 129 enum pwm_polarity polarity); 130 int (*enable)(struct pwm_chip *chip, 131 struct pwm_device *pwm); 132 void (*disable)(struct pwm_chip *chip, 133 struct pwm_device *pwm); 134 #ifdef CONFIG_DEBUG_FS 135 void (*dbg_show)(struct pwm_chip *chip, 136 struct seq_file *s); 137 #endif 138 struct module *owner; 139 }; 140 141 /** 142 * struct pwm_chip - abstract a PWM controller 143 * @dev: device providing the PWMs 144 * @list: list node for internal use 145 * @ops: callbacks for this PWM controller 146 * @base: number of first PWM controlled by this chip 147 * @npwm: number of PWMs controlled by this chip 148 * @pwms: array of PWM devices allocated by the framework 149 */ 150 struct pwm_chip { 151 struct device *dev; 152 struct list_head list; 153 const struct pwm_ops *ops; 154 int base; 155 unsigned int npwm; 156 157 struct pwm_device *pwms; 158 159 struct pwm_device * (*of_xlate)(struct pwm_chip *pc, 160 const struct of_phandle_args *args); 161 unsigned int of_pwm_n_cells; 162 }; 163 164 #if IS_ENABLED(CONFIG_PWM) 165 int pwm_set_chip_data(struct pwm_device *pwm, void *data); 166 void *pwm_get_chip_data(struct pwm_device *pwm); 167 168 int pwmchip_add(struct pwm_chip *chip); 169 int pwmchip_remove(struct pwm_chip *chip); 170 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 171 unsigned int index, 172 const char *label); 173 174 struct pwm_device *pwm_get(struct device *dev, const char *consumer); 175 void pwm_put(struct pwm_device *pwm); 176 177 struct pwm_device *devm_pwm_get(struct device *dev, const char *consumer); 178 void devm_pwm_put(struct device *dev, struct pwm_device *pwm); 179 #else 180 static inline int pwm_set_chip_data(struct pwm_device *pwm, void *data) 181 { 182 return -EINVAL; 183 } 184 185 static inline void *pwm_get_chip_data(struct pwm_device *pwm) 186 { 187 return NULL; 188 } 189 190 static inline int pwmchip_add(struct pwm_chip *chip) 191 { 192 return -EINVAL; 193 } 194 195 static inline int pwmchip_remove(struct pwm_chip *chip) 196 { 197 return -EINVAL; 198 } 199 200 static inline struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, 201 unsigned int index, 202 const char *label) 203 { 204 return ERR_PTR(-ENODEV); 205 } 206 207 static inline struct pwm_device *pwm_get(struct device *dev, 208 const char *consumer) 209 { 210 return ERR_PTR(-ENODEV); 211 } 212 213 static inline void pwm_put(struct pwm_device *pwm) 214 { 215 } 216 217 static inline struct pwm_device *devm_pwm_get(struct device *dev, 218 const char *consumer) 219 { 220 return ERR_PTR(-ENODEV); 221 } 222 223 static inline void devm_pwm_put(struct device *dev, struct pwm_device *pwm) 224 { 225 } 226 #endif 227 228 struct pwm_lookup { 229 struct list_head list; 230 const char *provider; 231 unsigned int index; 232 const char *dev_id; 233 const char *con_id; 234 }; 235 236 #define PWM_LOOKUP(_provider, _index, _dev_id, _con_id) \ 237 { \ 238 .provider = _provider, \ 239 .index = _index, \ 240 .dev_id = _dev_id, \ 241 .con_id = _con_id, \ 242 } 243 244 #if IS_ENABLED(CONFIG_PWM) 245 void pwm_add_table(struct pwm_lookup *table, size_t num); 246 #else 247 static inline void pwm_add_table(struct pwm_lookup *table, size_t num) 248 { 249 } 250 #endif 251 252 #endif /* __LINUX_PWM_H */ 253