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 (*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  */
 107 struct 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
 115 static inline struct serdev_controller *to_serdev_controller(struct device *d)
 116 {
 117         return container_of(d, struct serdev_controller, dev);
 118 }
 119
 120 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
 121 {
 122         return dev_get_drvdata(&serdev->dev);
 123 }
 124
 125 static 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  */
 134 static inline void serdev_device_put(struct serdev_device *serdev)
 135 {
 136         if (serdev)
 137                 put_device(&serdev->dev);
 138 }
 139
 140 static 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
 146 static inline
 147 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
 148 {
 149         return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
 150 }
 151
 152 static 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  */
 162 static inline void serdev_controller_put(struct serdev_controller *ctrl)
 163 {
 164         if (ctrl)
 165                 put_device(&ctrl->dev);
 166 }
 167
 168 struct serdev_device *serdev_device_alloc(struct serdev_controller *);
 169 int serdev_device_add(struct serdev_device *);
 170 void serdev_device_remove(struct serdev_device *);
 171
 172 struct serdev_controller *serdev_controller_alloc(struct device *host,
 173                                                   struct device *parent,
 174                                                   size_t size);
 175 int serdev_controller_add(struct serdev_controller *);
 176 void serdev_controller_remove(struct serdev_controller *);
 177
 178 static 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
 188 static 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
 202 int serdev_device_open(struct serdev_device *);
 203 void serdev_device_close(struct serdev_device *);
 204 int devm_serdev_device_open(struct device *, struct serdev_device *);
 205 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
 206 void serdev_device_set_flow_control(struct serdev_device *, bool);
 207 int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t);
 208 void serdev_device_wait_until_sent(struct serdev_device *, long);
 209 int serdev_device_get_tiocm(struct serdev_device *);
 210 int serdev_device_set_tiocm(struct serdev_device *, int, int);
 211 int serdev_device_break_ctl(struct serdev_device *serdev, int break_state);
 212 void serdev_device_write_wakeup(struct serdev_device *);
 213 ssize_t serdev_device_write(struct serdev_device *, const u8 *, size_t, long);
 214 void serdev_device_write_flush(struct serdev_device *);
 215 int serdev_device_write_room(struct serdev_device *);
 216
 217 /*
 218  * serdev device driver functions
 219  */
 220 int __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  */
 228 static 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
 240 static inline int serdev_device_open(struct serdev_device *sdev)
 241 {
 242         return -ENODEV;
 243 }
 244 static inline void serdev_device_close(struct serdev_device *sdev) {}
 245 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
 246 {
 247         return 0;
 248 }
 249 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
 250 static inline int serdev_device_write_buf(struct serdev_device *serdev,
 251                                           const u8 *buf,
 252                                           size_t count)
 253 {
 254         return -ENODEV;
 255 }
 256 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
 257 static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
 258 {
 259         return -EOPNOTSUPP;
 260 }
 261 static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
 262 {
 263         return -EOPNOTSUPP;
 264 }
 265 static inline int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
 266 {
 267         return -EOPNOTSUPP;
 268 }
 269 static 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 }
 275 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
 276 static 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
 286 static 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
 292 static 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
 300 static 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
 308 int serdev_device_set_parity(struct serdev_device *serdev,
 309                              enum serdev_parity parity);
 310
 311 /*
 312  * serdev hooks into TTY core
 313  */
 314 struct tty_port;
 315 struct tty_driver;
 316
 317 #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
 318 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 int serdev_tty_port_unregister(struct tty_port *port);
 323 #else
 324 static 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 }
 331 static inline int serdev_tty_port_unregister(struct tty_port *port)
 332 {
 333         return -ENODEV;
 334 }
 335 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
 336
 337 struct acpi_resource;
 338 struct acpi_resource_uart_serialbus;
 339
 340 #ifdef CONFIG_ACPI
 341 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 342                                    struct acpi_resource_uart_serialbus **uart);
 343 #else
 344 static 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 */