1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org> 4 */ 5 #ifndef _LINUX_SERDEV_H 6 #define _LINUX_SERDEV_H 7 8 #include <linux/types.h> 9 #include <linux/device.h> 10 #include <linux/termios.h> 11 #include <linux/delay.h> 12 13 struct serdev_controller; 14 struct serdev_device; 15 16 /* 17 * serdev device structures 18 */ 19 20 /** 21 * struct serdev_device_ops - Callback operations for a serdev device 22 * @receive_buf: Function called with data received from device; 23 * returns number of bytes accepted; may sleep. 24 * @write_wakeup: Function called when ready to transmit more data; must 25 * not sleep. 26 */ 27 struct serdev_device_ops { 28 int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t); 29 void (*write_wakeup)(struct serdev_device *); 30 }; 31 32 /** 33 * struct serdev_device - Basic representation of an serdev device 34 * @dev: Driver model representation of the device. 35 * @nr: Device number on serdev bus. 36 * @ctrl: serdev controller managing this device. 37 * @ops: Device operations. 38 * @write_comp Completion used by serdev_device_write() internally 39 * @write_lock Lock to serialize access when writing data 40 */ 41 struct serdev_device { 42 struct device dev; 43 int nr; 44 struct serdev_controller *ctrl; 45 const struct serdev_device_ops *ops; 46 struct completion write_comp; 47 struct mutex write_lock; 48 }; 49 50 static inline struct serdev_device *to_serdev_device(struct device *d) 51 { 52 return container_of(d, struct serdev_device, dev); 53 } 54 55 /** 56 * struct serdev_device_driver - serdev slave device driver 57 * @driver: serdev device drivers should initialize name field of this 58 * structure. 59 * @probe: binds this driver to a serdev device. 60 * @remove: unbinds this driver from the serdev device. 61 */ 62 struct serdev_device_driver { 63 struct device_driver driver; 64 int (*probe)(struct serdev_device *); 65 void (*remove)(struct serdev_device *); 66 }; 67 68 static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d) 69 { 70 return container_of(d, struct serdev_device_driver, driver); 71 } 72 73 enum serdev_parity { 74 SERDEV_PARITY_NONE, 75 SERDEV_PARITY_EVEN, 76 SERDEV_PARITY_ODD, 77 }; 78 79 /* 80 * serdev controller structures 81 */ 82 struct serdev_controller_ops { 83 int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t); 84 void (*write_flush)(struct serdev_controller *); 85 int (*write_room)(struct serdev_controller *); 86 int (*open)(struct serdev_controller *); 87 void (*close)(struct serdev_controller *); 88 void (*set_flow_control)(struct serdev_controller *, bool); 89 int (*set_parity)(struct serdev_controller *, enum serdev_parity); 90 unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int); 91 void (*wait_until_sent)(struct serdev_controller *, long); 92 int (*get_tiocm)(struct serdev_controller *); 93 int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int); 94 }; 95 96 /** 97 * struct serdev_controller - interface to the serdev controller 98 * @dev: Driver model representation of the device. 99 * @nr: number identifier for this controller/bus. 100 * @serdev: Pointer to slave device for this controller. 101 * @ops: Controller operations. 102 */ 103 struct serdev_controller { 104 struct device dev; 105 unsigned int nr; 106 struct serdev_device *serdev; 107 const struct serdev_controller_ops *ops; 108 }; 109 110 static inline struct serdev_controller *to_serdev_controller(struct device *d) 111 { 112 return container_of(d, struct serdev_controller, dev); 113 } 114 115 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev) 116 { 117 return dev_get_drvdata(&serdev->dev); 118 } 119 120 static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data) 121 { 122 dev_set_drvdata(&serdev->dev, data); 123 } 124 125 /** 126 * serdev_device_put() - decrement serdev device refcount 127 * @serdev serdev device. 128 */ 129 static inline void serdev_device_put(struct serdev_device *serdev) 130 { 131 if (serdev) 132 put_device(&serdev->dev); 133 } 134 135 static inline void serdev_device_set_client_ops(struct serdev_device *serdev, 136 const struct serdev_device_ops *ops) 137 { 138 serdev->ops = ops; 139 } 140 141 static inline 142 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl) 143 { 144 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL; 145 } 146 147 static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl, 148 void *data) 149 { 150 dev_set_drvdata(&ctrl->dev, data); 151 } 152 153 /** 154 * serdev_controller_put() - decrement controller refcount 155 * @ctrl serdev controller. 156 */ 157 static inline void serdev_controller_put(struct serdev_controller *ctrl) 158 { 159 if (ctrl) 160 put_device(&ctrl->dev); 161 } 162 163 struct serdev_device *serdev_device_alloc(struct serdev_controller *); 164 int serdev_device_add(struct serdev_device *); 165 void serdev_device_remove(struct serdev_device *); 166 167 struct serdev_controller *serdev_controller_alloc(struct device *, size_t); 168 int serdev_controller_add(struct serdev_controller *); 169 void serdev_controller_remove(struct serdev_controller *); 170 171 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl) 172 { 173 struct serdev_device *serdev = ctrl->serdev; 174 175 if (!serdev || !serdev->ops->write_wakeup) 176 return; 177 178 serdev->ops->write_wakeup(serdev); 179 } 180 181 static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl, 182 const unsigned char *data, 183 size_t count) 184 { 185 struct serdev_device *serdev = ctrl->serdev; 186 187 if (!serdev || !serdev->ops->receive_buf) 188 return 0; 189 190 return serdev->ops->receive_buf(serdev, data, count); 191 } 192 193 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS) 194 195 int serdev_device_open(struct serdev_device *); 196 void serdev_device_close(struct serdev_device *); 197 int devm_serdev_device_open(struct device *, struct serdev_device *); 198 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int); 199 void serdev_device_set_flow_control(struct serdev_device *, bool); 200 int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t); 201 void serdev_device_wait_until_sent(struct serdev_device *, long); 202 int serdev_device_get_tiocm(struct serdev_device *); 203 int serdev_device_set_tiocm(struct serdev_device *, int, int); 204 void serdev_device_write_wakeup(struct serdev_device *); 205 int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long); 206 void serdev_device_write_flush(struct serdev_device *); 207 int serdev_device_write_room(struct serdev_device *); 208 209 /* 210 * serdev device driver functions 211 */ 212 int __serdev_device_driver_register(struct serdev_device_driver *, struct module *); 213 #define serdev_device_driver_register(sdrv) \ 214 __serdev_device_driver_register(sdrv, THIS_MODULE) 215 216 /** 217 * serdev_device_driver_unregister() - unregister an serdev client driver 218 * @sdrv: the driver to unregister 219 */ 220 static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv) 221 { 222 if (sdrv) 223 driver_unregister(&sdrv->driver); 224 } 225 226 #define module_serdev_device_driver(__serdev_device_driver) \ 227 module_driver(__serdev_device_driver, serdev_device_driver_register, \ 228 serdev_device_driver_unregister) 229 230 #else 231 232 static inline int serdev_device_open(struct serdev_device *sdev) 233 { 234 return -ENODEV; 235 } 236 static inline void serdev_device_close(struct serdev_device *sdev) {} 237 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate) 238 { 239 return 0; 240 } 241 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {} 242 static inline int serdev_device_write_buf(struct serdev_device *serdev, 243 const unsigned char *buf, 244 size_t count) 245 { 246 return -ENODEV; 247 } 248 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {} 249 static inline int serdev_device_get_tiocm(struct serdev_device *serdev) 250 { 251 return -ENOTSUPP; 252 } 253 static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 254 { 255 return -ENOTSUPP; 256 } 257 static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf, 258 size_t count, unsigned long timeout) 259 { 260 return -ENODEV; 261 } 262 static inline void serdev_device_write_flush(struct serdev_device *sdev) {} 263 static inline int serdev_device_write_room(struct serdev_device *sdev) 264 { 265 return 0; 266 } 267 268 #define serdev_device_driver_register(x) 269 #define serdev_device_driver_unregister(x) 270 271 #endif /* CONFIG_SERIAL_DEV_BUS */ 272 273 static inline bool serdev_device_get_cts(struct serdev_device *serdev) 274 { 275 int status = serdev_device_get_tiocm(serdev); 276 return !!(status & TIOCM_CTS); 277 } 278 279 static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms) 280 { 281 unsigned long timeout; 282 bool signal; 283 284 timeout = jiffies + msecs_to_jiffies(timeout_ms); 285 while (time_is_after_jiffies(timeout)) { 286 signal = serdev_device_get_cts(serdev); 287 if (signal == state) 288 return 0; 289 usleep_range(1000, 2000); 290 } 291 292 return -ETIMEDOUT; 293 } 294 295 static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable) 296 { 297 if (enable) 298 return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0); 299 else 300 return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS); 301 } 302 303 int serdev_device_set_parity(struct serdev_device *serdev, 304 enum serdev_parity parity); 305 306 /* 307 * serdev hooks into TTY core 308 */ 309 struct tty_port; 310 struct tty_driver; 311 312 #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT 313 struct device *serdev_tty_port_register(struct tty_port *port, 314 struct device *parent, 315 struct tty_driver *drv, int idx); 316 int serdev_tty_port_unregister(struct tty_port *port); 317 #else 318 static inline struct device *serdev_tty_port_register(struct tty_port *port, 319 struct device *parent, 320 struct tty_driver *drv, int idx) 321 { 322 return ERR_PTR(-ENODEV); 323 } 324 static inline int serdev_tty_port_unregister(struct tty_port *port) 325 { 326 return -ENODEV; 327 } 328 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */ 329 330 #endif /*_LINUX_SERDEV_H */ 331