/* SPDX-License-Identifier: GPL-2.0-only */
/*
* FSI master definitions. These comprise the core <--> master interface,
* to allow the core to interact with the (hardware-specific) masters.
*
* Copyright (C) IBM Corporation 2016
*/
#ifndef DRIVERS_FSI_MASTER_H
#define DRIVERS_FSI_MASTER_H
#include <linux/device.h>
#include <linux/mutex.h>
/* Various protocol delays */
#define FSI_ECHO_DELAY_CLOCKS 16 /* Number clocks for echo delay */
#define FSI_SEND_DELAY_CLOCKS 16 /* Number clocks for send delay */
#define FSI_PRE_BREAK_CLOCKS 50 /* Number clocks to prep for break */
#define FSI_BREAK_CLOCKS 256 /* Number of clocks to issue break */
#define FSI_POST_BREAK_CLOCKS 16000 /* Number clocks to set up cfam */
#define FSI_INIT_CLOCKS 5000 /* Clock out any old data */
#define FSI_MASTER_DPOLL_CLOCKS 50 /* < 21 will cause slave to hang */
#define FSI_MASTER_EPOLL_CLOCKS 50 /* Number of clocks for E_POLL retry */
/* Various retry maximums */
#define FSI_CRC_ERR_RETRIES 10
#define FSI_MASTER_MAX_BUSY 200
#define FSI_MASTER_MTOE_COUNT 1000
/* Command encodings */
#define FSI_CMD_DPOLL 0x2
#define FSI_CMD_EPOLL 0x3
#define FSI_CMD_TERM 0x3f
#define FSI_CMD_ABS_AR 0x4
#define FSI_CMD_REL_AR 0x5
#define FSI_CMD_SAME_AR 0x3 /* but only a 2-bit opcode... */
/* Slave responses */
#define FSI_RESP_ACK 0 /* Success */
#define FSI_RESP_BUSY 1 /* Slave busy */
#define FSI_RESP_ERRA 2 /* Any (misc) Error */
#define FSI_RESP_ERRC 3 /* Slave reports master CRC error */
/* Misc */
#define FSI_CRC_SIZE 4
/* fsi-master definition and flags */
#define FSI_MASTER_FLAG_SWCLOCK 0x1
struct fsi_master {
struct device dev;
int idx;
int n_links;
int flags;
struct mutex scan_lock;
int (*read)(struct fsi_master *, int link, uint8_t id,
uint32_t addr, void *val, size_t size);
int (*write)(struct fsi_master *, int link, uint8_t id,
uint32_t addr, const void *val, size_t size);
int (*term)(struct fsi_master *, int link, uint8_t id);
int (*send_break)(struct fsi_master *, int link);
int (*link_enable)(struct fsi_master *, int link);
int (*link_config)(struct fsi_master *, int link,
u8 t_send_delay, u8 t_echo_delay);
};
#define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev)
/**
* fsi_master registration & lifetime: the fsi_master_register() and
* fsi_master_unregister() functions will take ownership of the master, and
* ->dev in particular. The registration path performs a get_device(), which
* takes the first reference on the device. Similarly, the unregistration path
* performs a put_device(), which may well drop the last reference.
*
* This means that master implementations *may* need to hold their own
* reference (via get_device()) on master->dev. In particular, if the device's
* ->release callback frees the fsi_master, then fsi_master_unregister will
* invoke this free if no other reference is held.
*
* The same applies for the error path of fsi_master_register; if the call
* fails, dev->release will have been invoked.
*/
extern int fsi_master_register(struct fsi_master *master);
extern void fsi_master_unregister(struct fsi_master *master);
extern int fsi_master_rescan(struct fsi_master *master);
#endif /* DRIVERS_FSI_MASTER_H */
