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 };
  97
  98 /**
  99  * struct serdev_controller - interface to the serdev controller
 100  * @dev:        Driver model representation of the device.
 101  * @nr:         number identifier for this controller/bus.
 102  * @serdev:     Pointer to slave device for this controller.
 103  * @ops:        Controller operations.
 104  */
 105 struct serdev_controller {
 106         struct device           dev;
 107         unsigned int            nr;
 108         struct serdev_device    *serdev;
 109         const struct serdev_controller_ops *ops;
 110 };
 111
 112 static inline struct serdev_controller *to_serdev_controller(struct device *d)
 113 {
 114         return container_of(d, struct serdev_controller, dev);
 115 }
 116
 117 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
 118 {
 119         return dev_get_drvdata(&serdev->dev);
 120 }
 121
 122 static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
 123 {
 124         dev_set_drvdata(&serdev->dev, data);
 125 }
 126
 127 /**
 128  * serdev_device_put() - decrement serdev device refcount
 129  * @serdev      serdev device.
 130  */
 131 static inline void serdev_device_put(struct serdev_device *serdev)
 132 {
 133         if (serdev)
 134                 put_device(&serdev->dev);
 135 }
 136
 137 static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
 138                                               const struct serdev_device_ops *ops)
 139 {
 140         serdev->ops = ops;
 141 }
 142
 143 static inline
 144 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
 145 {
 146         return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
 147 }
 148
 149 static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
 150                                                void *data)
 151 {
 152         dev_set_drvdata(&ctrl->dev, data);
 153 }
 154
 155 /**
 156  * serdev_controller_put() - decrement controller refcount
 157  * @ctrl        serdev controller.
 158  */
 159 static inline void serdev_controller_put(struct serdev_controller *ctrl)
 160 {
 161         if (ctrl)
 162                 put_device(&ctrl->dev);
 163 }
 164
 165 struct serdev_device *serdev_device_alloc(struct serdev_controller *);
 166 int serdev_device_add(struct serdev_device *);
 167 void serdev_device_remove(struct serdev_device *);
 168
 169 struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
 170 int serdev_controller_add(struct serdev_controller *);
 171 void serdev_controller_remove(struct serdev_controller *);
 172
 173 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
 174 {
 175         struct serdev_device *serdev = ctrl->serdev;
 176
 177         if (!serdev || !serdev->ops->write_wakeup)
 178                 return;
 179
 180         serdev->ops->write_wakeup(serdev);
 181 }
 182
 183 static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
 184                                               const unsigned char *data,
 185                                               size_t count)
 186 {
 187         struct serdev_device *serdev = ctrl->serdev;
 188
 189         if (!serdev || !serdev->ops->receive_buf)
 190                 return 0;
 191
 192         return serdev->ops->receive_buf(serdev, data, count);
 193 }
 194
 195 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
 196
 197 int serdev_device_open(struct serdev_device *);
 198 void serdev_device_close(struct serdev_device *);
 199 int devm_serdev_device_open(struct device *, struct serdev_device *);
 200 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
 201 void serdev_device_set_flow_control(struct serdev_device *, bool);
 202 int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);
 203 void serdev_device_wait_until_sent(struct serdev_device *, long);
 204 int serdev_device_get_tiocm(struct serdev_device *);
 205 int serdev_device_set_tiocm(struct serdev_device *, int, int);
 206 void serdev_device_write_wakeup(struct serdev_device *);
 207 int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
 208 void serdev_device_write_flush(struct serdev_device *);
 209 int serdev_device_write_room(struct serdev_device *);
 210
 211 /*
 212  * serdev device driver functions
 213  */
 214 int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
 215 #define serdev_device_driver_register(sdrv) \
 216         __serdev_device_driver_register(sdrv, THIS_MODULE)
 217
 218 /**
 219  * serdev_device_driver_unregister() - unregister an serdev client driver
 220  * @sdrv:       the driver to unregister
 221  */
 222 static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
 223 {
 224         if (sdrv)
 225                 driver_unregister(&sdrv->driver);
 226 }
 227
 228 #define module_serdev_device_driver(__serdev_device_driver) \
 229         module_driver(__serdev_device_driver, serdev_device_driver_register, \
 230                         serdev_device_driver_unregister)
 231
 232 #else
 233
 234 static inline int serdev_device_open(struct serdev_device *sdev)
 235 {
 236         return -ENODEV;
 237 }
 238 static inline void serdev_device_close(struct serdev_device *sdev) {}
 239 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
 240 {
 241         return 0;
 242 }
 243 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
 244 static inline int serdev_device_write_buf(struct serdev_device *serdev,
 245                                           const unsigned char *buf,
 246                                           size_t count)
 247 {
 248         return -ENODEV;
 249 }
 250 static inline void serdev_device_wait_until_sent(struct serdev_device *sdev, long timeout) {}
 251 static inline int serdev_device_get_tiocm(struct serdev_device *serdev)
 252 {
 253         return -ENOTSUPP;
 254 }
 255 static inline int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
 256 {
 257         return -ENOTSUPP;
 258 }
 259 static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf,
 260                                       size_t count, unsigned long timeout)
 261 {
 262         return -ENODEV;
 263 }
 264 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
 265 static inline int serdev_device_write_room(struct serdev_device *sdev)
 266 {
 267         return 0;
 268 }
 269
 270 #define serdev_device_driver_register(x)
 271 #define serdev_device_driver_unregister(x)
 272
 273 #endif /* CONFIG_SERIAL_DEV_BUS */
 274
 275 static inline bool serdev_device_get_cts(struct serdev_device *serdev)
 276 {
 277         int status = serdev_device_get_tiocm(serdev);
 278         return !!(status & TIOCM_CTS);
 279 }
 280
 281 static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
 282 {
 283         bool signal;
 284
 285         return readx_poll_timeout(serdev_device_get_cts, serdev, signal, signal == state,
 286                                   2000, timeout_ms * 1000);
 287 }
 288
 289 static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
 290 {
 291         if (enable)
 292                 return serdev_device_set_tiocm(serdev, TIOCM_RTS, 0);
 293         else
 294                 return serdev_device_set_tiocm(serdev, 0, TIOCM_RTS);
 295 }
 296
 297 int serdev_device_set_parity(struct serdev_device *serdev,
 298                              enum serdev_parity parity);
 299
 300 /*
 301  * serdev hooks into TTY core
 302  */
 303 struct tty_port;
 304 struct tty_driver;
 305
 306 #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
 307 struct device *serdev_tty_port_register(struct tty_port *port,
 308                                         struct device *parent,
 309                                         struct tty_driver *drv, int idx);
 310 int serdev_tty_port_unregister(struct tty_port *port);
 311 #else
 312 static inline struct device *serdev_tty_port_register(struct tty_port *port,
 313                                            struct device *parent,
 314                                            struct tty_driver *drv, int idx)
 315 {
 316         return ERR_PTR(-ENODEV);
 317 }
 318 static inline int serdev_tty_port_unregister(struct tty_port *port)
 319 {
 320         return -ENODEV;
 321 }
 322 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
 323
 324 struct acpi_resource;
 325 struct acpi_resource_uart_serialbus;
 326
 327 #ifdef CONFIG_ACPI
 328 bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 329                                    struct acpi_resource_uart_serialbus **uart);
 330 #else
 331 static inline bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
 332                                                  struct acpi_resource_uart_serialbus **uart)
 333 {
 334         return false;
 335 }
 336 #endif /* CONFIG_ACPI */
 337
 338 #endif /*_LINUX_SERDEV_H */