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 */