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Diffstat (limited to 'drivers/slimbus/slimbus.h')
| -rw-r--r-- | drivers/slimbus/slimbus.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/drivers/slimbus/slimbus.h b/drivers/slimbus/slimbus.h new file mode 100644 index 000000000000..66657722f50f --- /dev/null +++ b/drivers/slimbus/slimbus.h @@ -0,0 +1,108 @@ +// 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 */ |