drivers/fsi/fsi-master.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * FSI master definitions. These comprise the core <--> master interface,
   4  * to allow the core to interact with the (hardware-specific) masters.
   5  *
   6  * Copyright (C) IBM Corporation 2016
   7  */
   8
   9 #ifndef DRIVERS_FSI_MASTER_H
  10 #define DRIVERS_FSI_MASTER_H
  11
  12 #include <linux/device.h>
  13 #include <linux/mutex.h>
  14
  15 /* Various protocol delays */
  16 #define FSI_ECHO_DELAY_CLOCKS   16      /* Number clocks for echo delay */
  17 #define FSI_SEND_DELAY_CLOCKS   16      /* Number clocks for send delay */
  18 #define FSI_PRE_BREAK_CLOCKS    50      /* Number clocks to prep for break */
  19 #define FSI_BREAK_CLOCKS        256     /* Number of clocks to issue break */
  20 #define FSI_POST_BREAK_CLOCKS   16000   /* Number clocks to set up cfam */
  21 #define FSI_INIT_CLOCKS         5000    /* Clock out any old data */
  22 #define FSI_MASTER_DPOLL_CLOCKS 50      /* < 21 will cause slave to hang */
  23 #define FSI_MASTER_EPOLL_CLOCKS 50      /* Number of clocks for E_POLL retry */
  24
  25 /* Various retry maximums */
  26 #define FSI_CRC_ERR_RETRIES     10
  27 #define FSI_MASTER_MAX_BUSY     200
  28 #define FSI_MASTER_MTOE_COUNT   1000
  29
  30 /* Command encodings */
  31 #define FSI_CMD_DPOLL           0x2
  32 #define FSI_CMD_EPOLL           0x3
  33 #define FSI_CMD_TERM            0x3f
  34 #define FSI_CMD_ABS_AR          0x4
  35 #define FSI_CMD_REL_AR          0x5
  36 #define FSI_CMD_SAME_AR         0x3     /* but only a 2-bit opcode... */
  37
  38 /* Slave responses */
  39 #define FSI_RESP_ACK            0       /* Success */
  40 #define FSI_RESP_BUSY           1       /* Slave busy */
  41 #define FSI_RESP_ERRA           2       /* Any (misc) Error */
  42 #define FSI_RESP_ERRC           3       /* Slave reports master CRC error */
  43
  44 /* Misc */
  45 #define FSI_CRC_SIZE            4
  46
  47 /* fsi-master definition and flags */
  48 #define FSI_MASTER_FLAG_SWCLOCK         0x1
  49
  50 struct fsi_master {
  51         struct device   dev;
  52         int             idx;
  53         int             n_links;
  54         int             flags;
  55         struct mutex    scan_lock;
  56         int             (*read)(struct fsi_master *, int link, uint8_t id,
  57                                 uint32_t addr, void *val, size_t size);
  58         int             (*write)(struct fsi_master *, int link, uint8_t id,
  59                                 uint32_t addr, const void *val, size_t size);
  60         int             (*term)(struct fsi_master *, int link, uint8_t id);
  61         int             (*send_break)(struct fsi_master *, int link);
  62         int             (*link_enable)(struct fsi_master *, int link);
  63         int             (*link_config)(struct fsi_master *, int link,
  64                                        u8 t_send_delay, u8 t_echo_delay);
  65 };
  66
  67 #define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev)
  68
  69 /**
  70  * fsi_master registration & lifetime: the fsi_master_register() and
  71  * fsi_master_unregister() functions will take ownership of the master, and
  72  * ->dev in particular. The registration path performs a get_device(), which
  73  * takes the first reference on the device. Similarly, the unregistration path
  74  * performs a put_device(), which may well drop the last reference.
  75  *
  76  * This means that master implementations *may* need to hold their own
  77  * reference (via get_device()) on master->dev. In particular, if the device's
  78  * ->release callback frees the fsi_master, then fsi_master_unregister will
  79  * invoke this free if no other reference is held.
  80  *
  81  * The same applies for the error path of fsi_master_register; if the call
  82  * fails, dev->release will have been invoked.
  83  */
  84 extern int fsi_master_register(struct fsi_master *master);
  85 extern void fsi_master_unregister(struct fsi_master *master);
  86
  87 extern int fsi_master_rescan(struct fsi_master *master);
  88
  89 #endif /* DRIVERS_FSI_MASTER_H */