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 #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
  58 struct 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  */
  92 extern int fsi_master_register(struct fsi_master *master);
  93 extern void fsi_master_unregister(struct fsi_master *master);
  94
  95 extern int fsi_master_rescan(struct fsi_master *master);
  96
  97 #endif /* DRIVERS_FSI_MASTER_H */