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/iopoll.h> 11#include <linux/uaccess.h> 12#include <linux/termios.h> 13#include <linux/delay.h> 14 15struct serdev_controller; 16struct 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 */ 29struct serdev_device_ops { 30 size_t (*receive_buf)(struct serdev_device *, const u8 *, 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 */ 43struct 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 52static 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 */ 64struct serdev_device_driver { 65 struct device_driver driver; 66 int (*probe)(struct serdev_device *); 67 void (*remove)(struct serdev_device *); 68}; 69 70static 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 75enum serdev_parity { 76 SERDEV_PARITY_NONE, 77 SERDEV_PARITY_EVEN, 78 SERDEV_PARITY_ODD, 79}; 80 81/* 82 * serdev controller structures 83 */ 84struct serdev_controller_ops { 85 ssize_t (*write_buf)(struct serdev_controller *, const u8 *, 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 * @host: Serial port hardware controller device 103 * @nr: number identifier for this controller/bus. 104 * @serdev: Pointer to slave device for this controller. 105 * @ops: Controller operations. 106 */ 107struct serdev_controller { 108 struct device dev; 109 struct device *host; 110 unsigned int nr; 111 struct serdev_device *serdev; 112 const struct serdev_controller_ops *ops; 113}; 114 115static inline struct serdev_controller *to_serdev_controller(struct device *d) 116{ 117 return container_of(d, struct serdev_controller, dev); 118} 119 120static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev) 121{ 122 return dev_get_drvdata(&serdev->dev); 123} 124 125static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data) 126{ 127 dev_set_drvdata(&serdev->dev, data); 128} 129 130/** 131 * serdev_device_put() - decrement serdev device refcount 132 * @serdev serdev device. 133 */ 134static inline void serdev_device_put(struct serdev_device *serdev) 135{ 136 if (serdev) 137 put_device(&serdev->dev); 138} 139 140static inline void serdev_device_set_client_ops(struct serdev_device *serdev, 141 const struct serdev_device_ops *ops) 142{ 143 serdev->ops = ops; 144} 145 146static inline 147void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl) 148{ 149 return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL; 150} 151 152static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl, 153 void *data) 154{ 155 dev_set_drvdata(&ctrl->dev, data); 156} 157 158/** 159 * serdev_controller_put() - decrement controller refcount 160 * @ctrl serdev controller. 161 */ 162static inline void serdev_controller_put(struct serdev_controller *ctrl) 163{ 164 if (ctrl) 165 put_device(&ctrl->dev); 166} 167 168struct serdev_device *serdev_device_alloc(struct serdev_controller *); 169int serdev_device_add(struct serdev_device *); 170void serdev_device_remove(struct serdev_device *); 171 172struct serdev_controller *serdev_controller_alloc(struct device *host, 173 struct device *parent, 174 size_t size); 175int serdev_controller_add(struct serdev_controller *); 176void serdev_controller_remove(struct serdev_controller *); 177 178static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl) 179{ 180 struct serdev_device *serdev = ctrl->serdev; 181 182 if (!serdev || !serdev->ops->write_wakeup) 183 return; 184 185 serdev->ops->write_wakeup(serdev); 186} 187 188static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl, 189 const u8 *data, 190 size_t count) 191{ 192 struct serdev_device *serdev = ctrl->serdev; 193 194 if (!serdev || !serdev->ops->receive_buf) 195 return 0; 196 197 return serdev->ops->receive_buf(serdev, data, count); 198} 199 200#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS) 201 202int serdev_device_open(struct serdev_device *); 203void serdev_device_close(struct serdev_device *); 204int devm_serdev_device_open(struct device *, struct serdev_device *); 205unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int); 206void serdev_device_set_flow_control(struct serdev_device *, bool); 207int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t); 208void serdev_device_wait_until_sent(struct serdev_device *, long); 209int serdev_device_get_tiocm(struct serdev_device *); 210int serdev_device_set_tiocm(struct serdev_device *, int, int); 211int serdev_device_break_ctl(struct serdev_device *serdev, int break_state); 212void serdev_device_write_wakeup(struct serdev_device *); 213ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long); 214void serdev_device_write_flush(struct serdev_device *); 215int serdev_device_write_room(struct serdev_device *); 216 217/* 218 * serdev device driver functions 219 */ 220int __serdev_device_driver_register(struct serdev_device_driver *, struct module *); 221#define serdev_device_driver_register(sdrv) \ 222 __serdev_device_driver_register(sdrv, THIS_MODULE) 223 224/** 225 * serdev_device_driver_unregister() - unregister an serdev client driver 226 * @sdrv: the driver to unregister 227 */ 228static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv) 229{ 230 if (sdrv) 231 driver_unregister(&sdrv->driver); 232} 233 234#define module_serdev_device_driver(__serdev_device_driver) \ 235 module_driver(__serdev_device_driver, serdev_device_driver_register, \ 236 serdev_device_driver_unregister) 237 238#else 239 240static inline int serdev_device_open(struct serdev_device *sdev) 241{ 242 return -ENODEV; 243} 244static inline void serdev_device_close(struct serdev_device *sdev) {} 245static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate) 246{ 247 return 0; 248} 249static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {} 250static inline int serdev_device_write_buf(struct serdev_device *serdev, 251 const u8 *buf, 252 size_t count) 253{ 254 return -ENODEV; 255} 256static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {} 257static inline int serdev_device_get_tiocm(struct serdev_device *serdev) 258{ 259 return -EOPNOTSUPP; 260} 261static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear) 262{ 263 return -EOPNOTSUPP; 264} 265static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state) 266{ 267 return -EOPNOTSUPP; 268} 269static inline ssize_t serdev_device_write(struct serdev_device *sdev, 270 const u8 *buf, size_t count, 271 unsigned long timeout) 272{ 273 return -ENODEV; 274} 275static inline void serdev_device_write_flush(struct serdev_device *sdev) {} 276static inline int serdev_device_write_room(struct serdev_device *sdev) 277{ 278 return 0; 279} 280 281#define serdev_device_driver_register(x) 282#define serdev_device_driver_unregister(x) 283 284#endif /* CONFIG_SERIAL_DEV_BUS */ 285 286static inline bool serdev_device_get_cts(struct serdev_device *serdev) 287{ 288 int status = serdev_device_get_tiocm(serdev); 289 return !!(status & TIOCM_CTS); 290} 291 292static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms) 293{ 294 bool signal; 295 296 return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state, 297 2000, timeout_ms * 1000); 298} 299 300static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable) 301{ 302 if (enable) 303 return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0); 304 else 305 return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS); 306} 307 308int serdev_device_set_parity(struct serdev_device *serdev, 309 enum serdev_parity parity); 310 311/* 312 * serdev hooks into TTY core 313 */ 314struct tty_port; 315struct tty_driver; 316 317#ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT 318struct device *serdev_tty_port_register(struct tty_port *port, 319 struct device *host, 320 struct device *parent, 321 struct tty_driver *drv, int idx); 322int serdev_tty_port_unregister(struct tty_port *port); 323#else 324static inline struct device *serdev_tty_port_register(struct tty_port *port, 325 struct device *host, 326 struct device *parent, 327 struct tty_driver *drv, int idx) 328{ 329 return ERR_PTR(-ENODEV); 330} 331static inline int serdev_tty_port_unregister(struct tty_port *port) 332{ 333 return -ENODEV; 334} 335#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */ 336 337struct acpi_resource; 338struct acpi_resource_uart_serialbus; 339 340#ifdef CONFIG_ACPI 341bool serdev_acpi_get_uart_resource(struct acpi_resource *ares, 342 struct acpi_resource_uart_serialbus **uart); 343#else 344static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares, 345 struct acpi_resource_uart_serialbus **uart) 346{ 347 return false; 348} 349#endif /* CONFIG_ACPI */ 350 351#endif /*_LINUX_SERDEV_H */ 352