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         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 */