include/linux/serdev.h

   1 /*
   2  * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <[email protected]>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13 #ifndef _LINUX_SERDEV_H
  14 #define _LINUX_SERDEV_H
  15
  16 #include <linux/types.h>
  17 #include <linux/device.h>
  18
  19 struct serdev_controller;
  20 struct serdev_device;
  21
  22 /*
  23  * serdev device structures
  24  */
  25
  26 /**
  27  * struct serdev_device_ops - Callback operations for a serdev device
  28  * @receive_buf:        Function called with data received from device.
  29  * @write_wakeup:       Function called when ready to transmit more data.
  30  */
  31 struct serdev_device_ops {
  32         int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t);
  33         void (*write_wakeup)(struct serdev_device *);
  34 };
  35
  36 /**
  37  * struct serdev_device - Basic representation of an serdev device
  38  * @dev:        Driver model representation of the device.
  39  * @nr:         Device number on serdev bus.
  40  * @ctrl:       serdev controller managing this device.
  41  * @ops:        Device operations.
  42  * @write_comp  Completion used by serdev_device_write() internally
  43  * @write_lock  Lock to serialize access when writing data
  44  */
  45 struct serdev_device {
  46         struct device dev;
  47         int nr;
  48         struct serdev_controller *ctrl;
  49         const struct serdev_device_ops *ops;
  50         struct completion write_comp;
  51         struct mutex write_lock;
  52 };
  53
  54 static inline struct serdev_device *to_serdev_device(struct device *d)
  55 {
  56         return container_of(d, struct serdev_device, dev);
  57 }
  58
  59 /**
  60  * struct serdev_device_driver - serdev slave device driver
  61  * @driver:     serdev device drivers should initialize name field of this
  62  *              structure.
  63  * @probe:      binds this driver to a serdev device.
  64  * @remove:     unbinds this driver from the serdev device.
  65  */
  66 struct serdev_device_driver {
  67         struct device_driver driver;
  68         int     (*probe)(struct serdev_device *);
  69         void    (*remove)(struct serdev_device *);
  70 };
  71
  72 static inline struct serdev_device_driver *to_serdev_device_driver(struct device_driver *d)
  73 {
  74         return container_of(d, struct serdev_device_driver, driver);
  75 }
  76
  77 /*
  78  * serdev controller structures
  79  */
  80 struct serdev_controller_ops {
  81         int (*write_buf)(struct serdev_controller *, const unsigned char *, size_t);
  82         void (*write_flush)(struct serdev_controller *);
  83         int (*write_room)(struct serdev_controller *);
  84         int (*open)(struct serdev_controller *);
  85         void (*close)(struct serdev_controller *);
  86         void (*set_flow_control)(struct serdev_controller *, bool);
  87         unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
  88 };
  89
  90 /**
  91  * struct serdev_controller - interface to the serdev controller
  92  * @dev:        Driver model representation of the device.
  93  * @nr:         number identifier for this controller/bus.
  94  * @serdev:     Pointer to slave device for this controller.
  95  * @ops:        Controller operations.
  96  */
  97 struct serdev_controller {
  98         struct device           dev;
  99         unsigned int            nr;
 100         struct serdev_device    *serdev;
 101         const struct serdev_controller_ops *ops;
 102 };
 103
 104 static inline struct serdev_controller *to_serdev_controller(struct device *d)
 105 {
 106         return container_of(d, struct serdev_controller, dev);
 107 }
 108
 109 static inline void *serdev_device_get_drvdata(const struct serdev_device *serdev)
 110 {
 111         return dev_get_drvdata(&serdev->dev);
 112 }
 113
 114 static inline void serdev_device_set_drvdata(struct serdev_device *serdev, void *data)
 115 {
 116         dev_set_drvdata(&serdev->dev, data);
 117 }
 118
 119 /**
 120  * serdev_device_put() - decrement serdev device refcount
 121  * @serdev      serdev device.
 122  */
 123 static inline void serdev_device_put(struct serdev_device *serdev)
 124 {
 125         if (serdev)
 126                 put_device(&serdev->dev);
 127 }
 128
 129 static inline void serdev_device_set_client_ops(struct serdev_device *serdev,
 130                                               const struct serdev_device_ops *ops)
 131 {
 132         serdev->ops = ops;
 133 }
 134
 135 static inline
 136 void *serdev_controller_get_drvdata(const struct serdev_controller *ctrl)
 137 {
 138         return ctrl ? dev_get_drvdata(&ctrl->dev) : NULL;
 139 }
 140
 141 static inline void serdev_controller_set_drvdata(struct serdev_controller *ctrl,
 142                                                void *data)
 143 {
 144         dev_set_drvdata(&ctrl->dev, data);
 145 }
 146
 147 /**
 148  * serdev_controller_put() - decrement controller refcount
 149  * @ctrl        serdev controller.
 150  */
 151 static inline void serdev_controller_put(struct serdev_controller *ctrl)
 152 {
 153         if (ctrl)
 154                 put_device(&ctrl->dev);
 155 }
 156
 157 struct serdev_device *serdev_device_alloc(struct serdev_controller *);
 158 int serdev_device_add(struct serdev_device *);
 159 void serdev_device_remove(struct serdev_device *);
 160
 161 struct serdev_controller *serdev_controller_alloc(struct device *, size_t);
 162 int serdev_controller_add(struct serdev_controller *);
 163 void serdev_controller_remove(struct serdev_controller *);
 164
 165 static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl)
 166 {
 167         struct serdev_device *serdev = ctrl->serdev;
 168
 169         if (!serdev || !serdev->ops->write_wakeup)
 170                 return;
 171
 172         serdev->ops->write_wakeup(serdev);
 173 }
 174
 175 static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
 176                                               const unsigned char *data,
 177                                               size_t count)
 178 {
 179         struct serdev_device *serdev = ctrl->serdev;
 180
 181         if (!serdev || !serdev->ops->receive_buf)
 182                 return -EINVAL;
 183
 184         return serdev->ops->receive_buf(serdev, data, count);
 185 }
 186
 187 #if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
 188
 189 int serdev_device_open(struct serdev_device *);
 190 void serdev_device_close(struct serdev_device *);
 191 unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
 192 void serdev_device_set_flow_control(struct serdev_device *, bool);
 193 void serdev_device_write_wakeup(struct serdev_device *);
 194 int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, unsigned long);
 195 void serdev_device_write_flush(struct serdev_device *);
 196 int serdev_device_write_room(struct serdev_device *);
 197
 198 /*
 199  * serdev device driver functions
 200  */
 201 int __serdev_device_driver_register(struct serdev_device_driver *, struct module *);
 202 #define serdev_device_driver_register(sdrv) \
 203         __serdev_device_driver_register(sdrv, THIS_MODULE)
 204
 205 /**
 206  * serdev_device_driver_unregister() - unregister an serdev client driver
 207  * @sdrv:       the driver to unregister
 208  */
 209 static inline void serdev_device_driver_unregister(struct serdev_device_driver *sdrv)
 210 {
 211         if (sdrv)
 212                 driver_unregister(&sdrv->driver);
 213 }
 214
 215 #define module_serdev_device_driver(__serdev_device_driver) \
 216         module_driver(__serdev_device_driver, serdev_device_driver_register, \
 217                         serdev_device_driver_unregister)
 218
 219 #else
 220
 221 static inline int serdev_device_open(struct serdev_device *sdev)
 222 {
 223         return -ENODEV;
 224 }
 225 static inline void serdev_device_close(struct serdev_device *sdev) {}
 226 static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate)
 227 {
 228         return 0;
 229 }
 230 static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}
 231 static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf,
 232                                       size_t count, unsigned long timeout)
 233 {
 234         return -ENODEV;
 235 }
 236 static inline void serdev_device_write_flush(struct serdev_device *sdev) {}
 237 static inline int serdev_device_write_room(struct serdev_device *sdev)
 238 {
 239         return 0;
 240 }
 241
 242 #define serdev_device_driver_register(x)
 243 #define serdev_device_driver_unregister(x)
 244
 245 #endif /* CONFIG_SERIAL_DEV_BUS */
 246
 247 /*
 248  * serdev hooks into TTY core
 249  */
 250 struct tty_port;
 251 struct tty_driver;
 252
 253 #ifdef CONFIG_SERIAL_DEV_CTRL_TTYPORT
 254 struct device *serdev_tty_port_register(struct tty_port *port,
 255                                         struct device *parent,
 256                                         struct tty_driver *drv, int idx);
 257 void serdev_tty_port_unregister(struct tty_port *port);
 258 #else
 259 static inline struct device *serdev_tty_port_register(struct tty_port *port,
 260                                            struct device *parent,
 261                                            struct tty_driver *drv, int idx)
 262 {
 263         return ERR_PTR(-ENODEV);
 264 }
 265 static inline void serdev_tty_port_unregister(struct tty_port *port) {}
 266 #endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */
 267
 268 static inline int serdev_device_write_buf(struct serdev_device *serdev,
 269                                           const unsigned char *data,
 270                                           size_t count)
 271 {
 272         return serdev_device_write(serdev, data, count, 0);
 273 }
 274
 275 #endif /*_LINUX_SERDEV_H */