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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2011-2017, The Linux Foundation
*/
#ifndef _DRIVERS_SLIMBUS_H
#define _DRIVERS_SLIMBUS_H
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/slimbus.h>
/* Standard values per SLIMbus spec needed by controllers and devices */
#define SLIM_MAX_CLK_GEAR 10
#define SLIM_MIN_CLK_GEAR 1
/* Manager's logical address is set to 0xFF per spec */
#define SLIM_LA_MANAGER 0xFF
/**
* struct slim_framer - Represents SLIMbus framer.
* Every controller may have multiple framers. There is 1 active framer device
* responsible for clocking the bus.
* Manager is responsible for framer hand-over.
* @dev: Driver model representation of the device.
* @e_addr: Enumeration address of the framer.
* @rootfreq: Root Frequency at which the framer can run. This is maximum
* frequency ('clock gear 10') at which the bus can operate.
* @superfreq: Superframes per root frequency. Every frame is 6144 bits.
*/
struct slim_framer {
struct device dev;
struct slim_eaddr e_addr;
int rootfreq;
int superfreq;
};
#define to_slim_framer(d) container_of(d, struct slim_framer, dev)
/**
* struct slim_controller - Controls every instance of SLIMbus
* (similar to 'master' on SPI)
* @dev: Device interface to this driver
* @id: Board-specific number identifier for this controller/bus
* @name: Name for this controller
* @min_cg: Minimum clock gear supported by this controller (default value: 1)
* @max_cg: Maximum clock gear supported by this controller (default value: 10)
* @clkgear: Current clock gear in which this bus is running
* @laddr_ida: logical address id allocator
* @a_framer: Active framer which is clocking the bus managed by this controller
* @lock: Mutex protecting controller data structures
* @devices: Slim device list
* @tid_idr: tid id allocator
* @txn_lock: Lock to protect table of transactions
* @set_laddr: Setup logical address at laddr for the slave with elemental
* address e_addr. Drivers implementing controller will be expected to
* send unicast message to this device with its logical address.
* @get_laddr: It is possible that controller needs to set fixed logical
* address table and get_laddr can be used in that case so that controller
* can do this assignment. Use case is when the master is on the remote
* processor side, who is resposible for allocating laddr.
*
* 'Manager device' is responsible for device management, bandwidth
* allocation, channel setup, and port associations per channel.
* Device management means Logical address assignment/removal based on
* enumeration (report-present, report-absent) of a device.
* Bandwidth allocation is done dynamically by the manager based on active
* channels on the bus, message-bandwidth requests made by SLIMbus devices.
* Based on current bandwidth usage, manager chooses a frequency to run
* the bus at (in steps of 'clock-gear', 1 through 10, each clock gear
* representing twice the frequency than the previous gear).
* Manager is also responsible for entering (and exiting) low-power-mode
* (known as 'clock pause').
* Manager can do handover of framer if there are multiple framers on the
* bus and a certain usecase warrants using certain framer to avoid keeping
* previous framer being powered-on.
*
* Controller here performs duties of the manager device, and 'interface
* device'. Interface device is responsible for monitoring the bus and
* reporting information such as loss-of-synchronization, data
* slot-collision.
*/
struct slim_controller {
struct device *dev;
unsigned int id;
char name[SLIMBUS_NAME_SIZE];
int min_cg;
int max_cg;
int clkgear;
struct ida laddr_ida;
struct slim_framer *a_framer;
struct mutex lock;
struct list_head devices;
struct idr tid_idr;
spinlock_t txn_lock;
int (*set_laddr)(struct slim_controller *ctrl,
struct slim_eaddr *ea, u8 laddr);
int (*get_laddr)(struct slim_controller *ctrl,
struct slim_eaddr *ea, u8 *laddr);
};
int slim_device_report_present(struct slim_controller *ctrl,
struct slim_eaddr *e_addr, u8 *laddr);
void slim_report_absent(struct slim_device *sbdev);
int slim_register_controller(struct slim_controller *ctrl);
int slim_unregister_controller(struct slim_controller *ctrl);
#endif /* _LINUX_SLIMBUS_H */
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