include/linux/serdev.h

   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
  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         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  */
  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         ssize_t (*write_buf)(struct serdev_controller *, const u8 *, size_t);
  86         void (*write_flush)(struct serdev_controller *);
  87         int (*open)(struct serdev_controller *);
  88         void (*close)(struct serdev_controller *);
  89         void (*set_flow_control)(struct serdev_controller *, bool);
  90         int (*set_parity)(struct serdev_controller *, enum serdev_parity);
  91         unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
  92         void (*wait_until_sent)(struct serdev_controller *, long);
  93         int (*get_tiocm)(struct serdev_controller *);
  94         int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int);
  95         int (*break_ctl)(struct serdev_controller *ctrl, unsigned int break_state);
  96 };
  97
  98 /**
  99  * struct serdev_controller - interface to the serdev controller
 100  * @dev:        Driver model representation of the device.
 101  * @host:       Serial port hardware controller 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         struct device           *host;
 109         unsigned int            nr;
 110         struct serdev_device    *serdev;
 111         const struct serdev_controller_ops *ops;
 112 };
 113
 114 static inline struct serdev_controller *to_serdev_controller(struct device *d)
 115 {
 116         return container_of(d, struct serdev_controller, dev);
 117 }
 118
 119 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
 120 {
 121         return dev_get_drvdata(&serdev->dev);
 122 }
 123
 124 static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
 125 {
 126         dev_set_drvdata(&serdev->dev, data);
 127 }
 128
 129 /**
 130  * serdev_device_put() - decrement serdev device refcount
 131  * @serdev      serdev device.
 132  */
 133 static inline void serdev_device_put(struct serdev_device *serdev)
 134 {
 135         if (serdev)
 136                 put_device(&serdev->dev);
 137 }
 138
 139 static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
 140                                               const struct serdev_device_ops *ops)
 141 {
 142         serdev->ops = ops;
 143 }
 144
 145 static inline
 146 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
 147 {
 148         return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
 149 }
 150
 151 static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
 152                                                void *data)
 153 {
 154         dev_set_drvdata(&ctrl->dev, data);
 155 }
 156
 157 /**
 158  * serdev_controller_put() - decrement controller refcount
 159  * @ctrl        serdev controller.
 160  */
 161 static inline void serdev_controller_put(struct serdev_controller *ctrl)
 162 {
 163         if (ctrl)
 164                 put_device(&ctrl->dev);
 165 }
 166
 167 struct serdev_device *serdev_device_alloc(struct serdev_controller *);
 168 int serdev_device_add(struct serdev_device *);
 169 void serdev_device_remove(struct serdev_device *);
 170
 171 struct serdev_controller *serdev_controller_alloc(struct device *host,
 172                                                   struct device *parent,
 173                                                   size_t size);
 174 int serdev_controller_add(struct serdev_controller *);
 175 void serdev_controller_remove(struct serdev_controller *);
 176
 177 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
 178 {
 179         struct serdev_device *serdev = ctrl->serdev;
 180
 181         if (!serdev || !serdev->ops->write_wakeup)
 182                 return;
 183
 184         serdev->ops->write_wakeup(serdev);
 185 }
 186
 187 static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
 188                                                    const u8 *data,
 189                                                    size_t count)
 190 {
 191         struct serdev_device *serdev = ctrl->serdev;
 192
 193         if (!serdev || !serdev->ops->receive_buf)
 194                 return 0;
 195
 196         return serdev->ops->receive_buf(serdev, data, count);
 197 }
 198
 199 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
 200
 201 int serdev_device_open(struct serdev_device *);
 202 void serdev_device_close(struct serdev_device *);
 203 int devm_serdev_device_open(struct device *, struct serdev_device *);
 204 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
 205 void serdev_device_set_flow_control(struct serdev_device *, bool);
 206 int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t);
 207 void serdev_device_wait_until_sent(struct serdev_device *, long);
 208 int serdev_device_get_tiocm(struct serdev_device *);
 209 int serdev_device_set_tiocm(struct serdev_device *, int, int);
 210 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
 211 void serdev_device_write_wakeup(struct serdev_device *);
 212 ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long);
 213 void serdev_device_write_flush(struct serdev_device *);
 214
 215 /*
 216  * serdev device driver functions
 217  */
 218 int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
 219 #define serdev_device_driver_register(sdrv) \
 220         __serdev_device_driver_register(sdrv, THIS_MODULE)
 221
 222 /**
 223  * serdev_device_driver_unregister() - unregister an serdev client driver
 224  * @sdrv:       the driver to unregister
 225  */
 226 static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
 227 {
 228         if (sdrv)
 229                 driver_unregister(&sdrv->driver);
 230 }
 231
 232 #define module_serdev_device_driver(__serdev_device_driver) \
 233         module_driver(__serdev_device_driver, serdev_device_driver_register, \
 234                         serdev_device_driver_unregister)
 235
 236 #else
 237
 238 static inline int serdev_device_open(struct serdev_device *sdev)
 239 {
 240         return -ENODEV;
 241 }
 242 static inline void serdev_device_close(struct serdev_device *sdev) {}
 243 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
 244 {
 245         return 0;
 246 }
 247 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
 248 static inline int serdev_device_write_buf(struct serdev_device *serdev,
 249                                           const u8 *buf,
 250                                           size_t count)
 251 {
 252         return -ENODEV;
 253 }
 254 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
 255 static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
 256 {
 257         return -EOPNOTSUPP;
 258 }
 259 static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
 260 {
 261         return -EOPNOTSUPP;
 262 }
 263 static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
 264 {
 265         return -EOPNOTSUPP;
 266 }
 267 static inline ssize_t serdev_device_write(struct serdev_device *sdev,
 268                                           const u8 *buf, size_t count,
 269                                           unsigned long timeout)
 270 {
 271         return -ENODEV;
 272 }
 273 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
 274
 275 #define serdev_device_driver_register(x)
 276 #define serdev_device_driver_unregister(x)
 277
 278 #endif /* CONFIG_SERIAL_DEV_BUS */
 279
 280 static inline bool serdev_device_get_cts(struct serdev_device *serdev)
 281 {
 282         int status = serdev_device_get_tiocm(serdev);
 283         return !!(status & TIOCM_CTS);
 284 }
 285
 286 static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
 287 {
 288         bool signal;
 289
 290         return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state,
 291                                   2000, timeout_ms * 1000);
 292 }
 293
 294 static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
 295 {
 296         if (enable)
 297                 return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
 298         else
 299                 return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
 300 }
 301
 302 int serdev_device_set_parity(struct serdev_device *serdev,
 303                              enum serdev_parity parity);
 304
 305 /*
 306  * serdev hooks into TTY core
 307  */
 308 struct tty_port;
 309 struct tty_driver;
 310
 311 #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
 312 struct device *serdev_tty_port_register(struct tty_port *port,
 313                                         struct device *host,
 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 *host,
 320                                            struct device *parent,
 321                                            struct tty_driver *drv, int idx)
 322 {
 323         return ERR_PTR(-ENODEV);
 324 }
 325 static inline int serdev_tty_port_unregister(struct tty_port *port)
 326 {
 327         return -ENODEV;
 328 }
 329 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
 330
 331 struct acpi_resource;
 332 struct acpi_resource_uart_serialbus;
 333
 334 #ifdef CONFIG_ACPI
 335 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 336                                    struct acpi_resource_uart_serialbus **uart);
 337 #else
 338 static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 339                                                  struct acpi_resource_uart_serialbus **uart)
 340 {
 341         return false;
 342 }
 343 #endif /* CONFIG_ACPI */
 344
 345 #endif /*_LINUX_SERDEV_H */