drivers/fsi/fsi-master.h

   1 /*
   2  * FSI master definitions. These comprise the core <--> master interface,
   3  * to allow the core to interact with the (hardware-specific) masters.
   4  *
   5  * Copyright (C) IBM Corporation 2016
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #ifndef DRIVERS_FSI_MASTER_H
  18 #define DRIVERS_FSI_MASTER_H
  19
  20 #include <linux/device.h>
  21
  22 #define FSI_MASTER_FLAG_SWCLOCK         0x1
  23
  24 struct fsi_master {
  25         struct device   dev;
  26         int             idx;
  27         int             n_links;
  28         int             flags;
  29         int             (*read)(struct fsi_master *, int link, uint8_t id,
  30                                 uint32_t addr, void *val, size_t size);
  31         int             (*write)(struct fsi_master *, int link, uint8_t id,
  32                                 uint32_t addr, const void *val, size_t size);
  33         int             (*term)(struct fsi_master *, int link, uint8_t id);
  34         int             (*send_break)(struct fsi_master *, int link);
  35         int             (*link_enable)(struct fsi_master *, int link);
  36 };
  37
  38 #define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev)
  39
  40 /**
  41  * fsi_master registration & lifetime: the fsi_master_register() and
  42  * fsi_master_unregister() functions will take ownership of the master, and
  43  * ->dev in particular. The registration path performs a get_device(), which
  44  * takes the first reference on the device. Similarly, the unregistration path
  45  * performs a put_device(), which may well drop the last reference.
  46  *
  47  * This means that master implementations *may* need to hold their own
  48  * reference (via get_device()) on master->dev. In particular, if the device's
  49  * ->release callback frees the fsi_master, then fsi_master_unregister will
  50  * invoke this free if no other reference is held.
  51  *
  52  * The same applies for the error path of fsi_master_register; if the call
  53  * fails, dev->release will have been invoked.
  54  */
  55 extern int fsi_master_register(struct fsi_master *master);
  56 extern void fsi_master_unregister(struct fsi_master *master);
  57
  58 extern int fsi_master_rescan(struct fsi_master *master);
  59
  60 #endif /* DRIVERS_FSI_MASTER_H */