linux/drivers/fsi/fsi-master.h
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   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#include <linux/mutex.h>
  22
  23/* Various protocol delays */
  24#define FSI_ECHO_DELAY_CLOCKS   16      /* Number clocks for echo delay */
  25#define FSI_SEND_DELAY_CLOCKS   16      /* Number clocks for send delay */
  26#define FSI_PRE_BREAK_CLOCKS    50      /* Number clocks to prep for break */
  27#define FSI_BREAK_CLOCKS        256     /* Number of clocks to issue break */
  28#define FSI_POST_BREAK_CLOCKS   16000   /* Number clocks to set up cfam */
  29#define FSI_INIT_CLOCKS         5000    /* Clock out any old data */
  30#define FSI_MASTER_DPOLL_CLOCKS 50      /* < 21 will cause slave to hang */
  31#define FSI_MASTER_EPOLL_CLOCKS 50      /* Number of clocks for E_POLL retry */
  32
  33/* Various retry maximums */
  34#define FSI_CRC_ERR_RETRIES     10
  35#define FSI_MASTER_MAX_BUSY     200
  36#define FSI_MASTER_MTOE_COUNT   1000
  37
  38/* Command encodings */
  39#define FSI_CMD_DPOLL           0x2
  40#define FSI_CMD_EPOLL           0x3
  41#define FSI_CMD_TERM            0x3f
  42#define FSI_CMD_ABS_AR          0x4
  43#define FSI_CMD_REL_AR          0x5
  44#define FSI_CMD_SAME_AR         0x3     /* but only a 2-bit opcode... */
  45
  46/* Slave responses */
  47#define FSI_RESP_ACK            0       /* Success */
  48#define FSI_RESP_BUSY           1       /* Slave busy */
  49#define FSI_RESP_ERRA           2       /* Any (misc) Error */
  50#define FSI_RESP_ERRC           3       /* Slave reports master CRC error */
  51
  52/* Misc */
  53#define FSI_CRC_SIZE            4
  54
  55/* fsi-master definition and flags */
  56#define FSI_MASTER_FLAG_SWCLOCK         0x1
  57
  58struct fsi_master {
  59        struct device   dev;
  60        int             idx;
  61        int             n_links;
  62        int             flags;
  63        struct mutex    scan_lock;
  64        int             (*read)(struct fsi_master *, int link, uint8_t id,
  65                                uint32_t addr, void *val, size_t size);
  66        int             (*write)(struct fsi_master *, int link, uint8_t id,
  67                                uint32_t addr, const void *val, size_t size);
  68        int             (*term)(struct fsi_master *, int link, uint8_t id);
  69        int             (*send_break)(struct fsi_master *, int link);
  70        int             (*link_enable)(struct fsi_master *, int link);
  71        int             (*link_config)(struct fsi_master *, int link,
  72                                       u8 t_send_delay, u8 t_echo_delay);
  73};
  74
  75#define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev)
  76
  77/**
  78 * fsi_master registration & lifetime: the fsi_master_register() and
  79 * fsi_master_unregister() functions will take ownership of the master, and
  80 * ->dev in particular. The registration path performs a get_device(), which
  81 * takes the first reference on the device. Similarly, the unregistration path
  82 * performs a put_device(), which may well drop the last reference.
  83 *
  84 * This means that master implementations *may* need to hold their own
  85 * reference (via get_device()) on master->dev. In particular, if the device's
  86 * ->release callback frees the fsi_master, then fsi_master_unregister will
  87 * invoke this free if no other reference is held.
  88 *
  89 * The same applies for the error path of fsi_master_register; if the call
  90 * fails, dev->release will have been invoked.
  91 */
  92extern int fsi_master_register(struct fsi_master *master);
  93extern void fsi_master_unregister(struct fsi_master *master);
  94
  95extern int fsi_master_rescan(struct fsi_master *master);
  96
  97#endif /* DRIVERS_FSI_MASTER_H */
  98