1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <[email protected]> 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/iopoll.h> 11 #include <linux/uaccess.h> 12 #include <linux/termios.h> 13 #include <linux/delay.h> 14 15 struct serdev_controller; 16 struct serdev_device; 17 18 /* 19 * serdev device structures 20 */ 21 22 /** 23 * struct serdev_device_ops - Callback operations for a serdev device 24 * @receive_buf: Function called with data received from device; 25 * returns number of bytes accepted; may sleep. 26 * @write_wakeup: Function called when ready to transmit more data; must 27 * not sleep. 28 */ 29 struct serdev_device_ops { 30 int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t); 31 void (*write_wakeup)(struct serdev_device *); 32 }; 33 34 /** 35 * struct serdev_device - Basic representation of an serdev device 36 * @dev: Driver model representation of the device. 37 * @nr: Device number on serdev bus. 38 * @ctrl: serdev controller managing this device. 39 * @ops: Device operations. 40 * @write_comp Completion used by serdev_device_write() internally 41 * @write_lock Lock to serialize access when writing data 42 */ 43 struct serdev_device { 44 struct device dev; 45 int nr; 46 struct serdev_controller *ctrl; 47 const struct serdev_device_ops *ops; 48 struct completion write_comp; 49 struct mutex write_lock; 50 }; 51 52 static inline struct serdev_device *to_serdev_device(struct device *d) 53 { 54 return container_of(d, struct serdev_device, dev); 55 } 56 57 /** 58 * struct serdev_device_driver - serdev slave device driver 59 * @driver: serdev device drivers should initialize name field of this 60 * structure. 61 * @probe: binds this driver to a serdev device. 62 * @remove: unbinds this driver from the serdev device. 63 */ 64 struct serdev_device_driver { 65 struct device_driver driver; 66 int (*probe)(struct serdev_device *); 67 void (*remove)(struct serdev_device *); 68 }; 69 70 static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d) 71 { 72 return container_of(d, struct serdev_device_driver, driver); 73 } 74 75 enum serdev_parity { 76 SERDEV_PARITY_NONE, 77 SERDEV_PARITY_EVEN, 78 SERDEV_PARITY_ODD, 79 }; 80 81 /* 82 * serdev controller structures 83 */ 84 struct serdev_controller_ops { 85 int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t); 86 void (*write_flush)(struct serdev_controller *); 87 int (*write_room)(struct serdev_controller *); 88 int (*open)(struct serdev_controller *); 89 void (*close)(struct serdev_controller *); 90 void (*set_flow_control)(struct serdev_controller *, bool); 91 int (*set_parity)(struct serdev_controller *, enum serdev_parity); 92 unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int); 93 void (*wait_until_sent)(struct serdev_controller *, long); 94 int (*get_tiocm)(struct serdev_controller *); 95 int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int); 96 int (*break_ctl)(struct serdev_controller *ctrl, unsigned int break_state); 97 }; 98 99 /** 100 * struct serdev_controller - interface to the serdev controller 101 * @dev: Driver model representation of the device. 102 * @nr: number identifier for this controller/bus. 103 * @serdev: Pointer to slave device for this controller. 104 * @ops: Controller operations. 105 */ 106 struct serdev_controller { 107 struct device dev; 108 unsigned int nr; 109 struct serdev_device *serdev; 110 const struct serdev_controller_ops *ops; 111 }; 112 113 static inline struct serdev_controller *to_serdev_controller(struct device *d) 114 { 115 return container_of(d, struct serdev_controller, dev); 116 } 117 118 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev) 119 { 120 return dev_get_drvdata(&serdev->dev); 121 } 122 123 static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data) 124 { 125 dev_set_drvdata(&serdev->dev, data); 126 } 127 128 /** 129 * serdev_device_put() - decrement serdev device refcount 130 * @serdev serdev device. 131 */ 132 static inline void serdev_device_put(struct serdev_device *serdev) 133 { 134 if (serdev) 135 put_device(&serdev->dev); 136 } 137 138 static inline void serdev_device_set_client_ops(struct serdev_device *serdev, 139 const struct serdev_device_ops *ops) 140 { 141 serdev->ops = ops; 142 } 143 144 static inline 145 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl) 146 { 147 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL; 148 } 149 150 static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl, 151 void *data) 152 { 153 dev_set_drvdata(&ctrl->dev, data); 154 } 155 156 /** 157 * serdev_controller_put() - decrement controller refcount 158 * @ctrl serdev controller. 159 */ 160 static inline void serdev_controller_put(struct serdev_controller *ctrl) 161 { 162 if (ctrl) 163 put_device(&ctrl->dev); 164 } 165 166 struct serdev_device *serdev_device_alloc(struct serdev_controller *); 167 int serdev_device_add(struct serdev_device *); 168 void serdev_device_remove(struct serdev_device *); 169 170 struct serdev_controller *serdev_controller_alloc(struct device *, size_t); 171 int serdev_controller_add(struct serdev_controller *); 172 void serdev_controller_remove(struct serdev_controller *); 173 174 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl) 175 { 176 struct serdev_device *serdev = ctrl->serdev; 177 178 if (!serdev || !serdev->ops->write_wakeup) 179 return; 180 181 serdev->ops->write_wakeup(serdev); 182 } 183 184 static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl, 185 const unsigned char *data, 186 size_t count) 187 { 188 struct serdev_device *serdev = ctrl->serdev; 189 190 if (!serdev || !serdev->ops->receive_buf) 191 return 0; 192 193 return serdev->ops->receive_buf(serdev, data, count); 194 } 195 196 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS) 197 198 int serdev_device_open(struct serdev_device *); 199 void serdev_device_close(struct serdev_device *); 200 int devm_serdev_device_open(struct device *, struct serdev_device *); 201 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int); 202 void serdev_device_set_flow_control(struct serdev_device *, bool); 203 int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t); 204 void serdev_device_wait_until_sent(struct serdev_device *, long); 205 int serdev_device_get_tiocm(struct serdev_device *); 206 int serdev_device_set_tiocm(struct serdev_device *, int, int); 207 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state); 208 void serdev_device_write_wakeup(struct serdev_device *); 209 int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long); 210 void serdev_device_write_flush(struct serdev_device *); 211 int serdev_device_write_room(struct serdev_device *); 212 213 /* 214 * serdev device driver functions 215 */ 216 int __serdev_device_driver_register(struct serdev_device_driver *, struct module *); 217 #define serdev_device_driver_register(sdrv) \ 218 __serdev_device_driver_register(sdrv, THIS_MODULE) 219 220 /** 221 * serdev_device_driver_unregister() - unregister an serdev client driver 222 * @sdrv: the driver to unregister 223 */ 224 static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv) 225 { 226 if (sdrv) 227 driver_unregister(&sdrv->driver); 228 } 229 230 #define module_serdev_device_driver(__serdev_device_driver) \ 231 module_driver(__serdev_device_driver, serdev_device_driver_register, \ 232 serdev_device_driver_unregister) 233 234 #else 235 236 static inline int serdev_device_open(struct serdev_device *sdev) 237 { 238 return -ENODEV; 239 } 240 static inline void serdev_device_close(struct serdev_device *sdev) {} 241 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate) 242 { 243 return 0; 244 } 245 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {} 246 static inline int serdev_device_write_buf(struct serdev_device *serdev, 247 const unsigned char *buf, 248 size_t count) 249 { 250 return -ENODEV; 251 } 252 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {} 253 static inline int serdev_device_get_tiocm(struct serdev_device *serdev) 254 { 255 return -EOPNOTSUPP; 256 } 257 static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 258 { 259 return -EOPNOTSUPP; 260 } 261 static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state) 262 { 263 return -EOPNOTSUPP; 264 } 265 static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf, 266 size_t count, unsigned long timeout) 267 { 268 return -ENODEV; 269 } 270 static inline void serdev_device_write_flush(struct serdev_device *sdev) {} 271 static inline int serdev_device_write_room(struct serdev_device *sdev) 272 { 273 return 0; 274 } 275 276 #define serdev_device_driver_register(x) 277 #define serdev_device_driver_unregister(x) 278 279 #endif /* CONFIG_SERIAL_DEV_BUS */ 280 281 static inline bool serdev_device_get_cts(struct serdev_device *serdev) 282 { 283 int status = serdev_device_get_tiocm(serdev); 284 return !!(status & TIOCM_CTS); 285 } 286 287 static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms) 288 { 289 bool signal; 290 291 return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state, 292 2000, timeout_ms * 1000); 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 struct acpi_resource; 331 struct acpi_resource_uart_serialbus; 332 333 #ifdef CONFIG_ACPI 334 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares, 335 struct acpi_resource_uart_serialbus **uart); 336 #else 337 static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares, 338 struct acpi_resource_uart_serialbus **uart) 339 { 340 return false; 341 } 342 #endif /* CONFIG_ACPI */ 343 344 #endif /*_LINUX_SERDEV_H */ 345