| Sagar Dharia | 46a2bb5 | 2017-12-11 23:42:58 +0000 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Copyright (c) 2011-2017, The Linux Foundation |
| 4 | */ |
| 5 | |
| 6 | #ifndef _DRIVERS_SLIMBUS_H |
| 7 | #define _DRIVERS_SLIMBUS_H |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/device.h> |
| 10 | #include <linux/mutex.h> |
| 11 | #include <linux/slimbus.h> |
| 12 | |
| 13 | /* Standard values per SLIMbus spec needed by controllers and devices */ |
| 14 | #define SLIM_MAX_CLK_GEAR 10 |
| 15 | #define SLIM_MIN_CLK_GEAR 1 |
| 16 | |
| 17 | /* Manager's logical address is set to 0xFF per spec */ |
| 18 | #define SLIM_LA_MANAGER 0xFF |
| 19 | |
| 20 | /** |
| 21 | * struct slim_framer - Represents SLIMbus framer. |
| 22 | * Every controller may have multiple framers. There is 1 active framer device |
| 23 | * responsible for clocking the bus. |
| 24 | * Manager is responsible for framer hand-over. |
| 25 | * @dev: Driver model representation of the device. |
| 26 | * @e_addr: Enumeration address of the framer. |
| 27 | * @rootfreq: Root Frequency at which the framer can run. This is maximum |
| 28 | * frequency ('clock gear 10') at which the bus can operate. |
| 29 | * @superfreq: Superframes per root frequency. Every frame is 6144 bits. |
| 30 | */ |
| 31 | struct slim_framer { |
| 32 | struct device dev; |
| 33 | struct slim_eaddr e_addr; |
| 34 | int rootfreq; |
| 35 | int superfreq; |
| 36 | }; |
| 37 | |
| 38 | #define to_slim_framer(d) container_of(d, struct slim_framer, dev) |
| 39 | |
| 40 | /** |
| 41 | * struct slim_controller - Controls every instance of SLIMbus |
| 42 | * (similar to 'master' on SPI) |
| 43 | * @dev: Device interface to this driver |
| 44 | * @id: Board-specific number identifier for this controller/bus |
| 45 | * @name: Name for this controller |
| 46 | * @min_cg: Minimum clock gear supported by this controller (default value: 1) |
| 47 | * @max_cg: Maximum clock gear supported by this controller (default value: 10) |
| 48 | * @clkgear: Current clock gear in which this bus is running |
| 49 | * @laddr_ida: logical address id allocator |
| 50 | * @a_framer: Active framer which is clocking the bus managed by this controller |
| 51 | * @lock: Mutex protecting controller data structures |
| 52 | * @devices: Slim device list |
| 53 | * @tid_idr: tid id allocator |
| 54 | * @txn_lock: Lock to protect table of transactions |
| 55 | * @set_laddr: Setup logical address at laddr for the slave with elemental |
| 56 | * address e_addr. Drivers implementing controller will be expected to |
| 57 | * send unicast message to this device with its logical address. |
| 58 | * @get_laddr: It is possible that controller needs to set fixed logical |
| 59 | * address table and get_laddr can be used in that case so that controller |
| 60 | * can do this assignment. Use case is when the master is on the remote |
| 61 | * processor side, who is resposible for allocating laddr. |
| 62 | * |
| 63 | * 'Manager device' is responsible for device management, bandwidth |
| 64 | * allocation, channel setup, and port associations per channel. |
| 65 | * Device management means Logical address assignment/removal based on |
| 66 | * enumeration (report-present, report-absent) of a device. |
| 67 | * Bandwidth allocation is done dynamically by the manager based on active |
| 68 | * channels on the bus, message-bandwidth requests made by SLIMbus devices. |
| 69 | * Based on current bandwidth usage, manager chooses a frequency to run |
| 70 | * the bus at (in steps of 'clock-gear', 1 through 10, each clock gear |
| 71 | * representing twice the frequency than the previous gear). |
| 72 | * Manager is also responsible for entering (and exiting) low-power-mode |
| 73 | * (known as 'clock pause'). |
| 74 | * Manager can do handover of framer if there are multiple framers on the |
| 75 | * bus and a certain usecase warrants using certain framer to avoid keeping |
| 76 | * previous framer being powered-on. |
| 77 | * |
| 78 | * Controller here performs duties of the manager device, and 'interface |
| 79 | * device'. Interface device is responsible for monitoring the bus and |
| 80 | * reporting information such as loss-of-synchronization, data |
| 81 | * slot-collision. |
| 82 | */ |
| 83 | struct slim_controller { |
| 84 | struct device *dev; |
| 85 | unsigned int id; |
| 86 | char name[SLIMBUS_NAME_SIZE]; |
| 87 | int min_cg; |
| 88 | int max_cg; |
| 89 | int clkgear; |
| 90 | struct ida laddr_ida; |
| 91 | struct slim_framer *a_framer; |
| 92 | struct mutex lock; |
| 93 | struct list_head devices; |
| 94 | struct idr tid_idr; |
| 95 | spinlock_t txn_lock; |
| 96 | int (*set_laddr)(struct slim_controller *ctrl, |
| 97 | struct slim_eaddr *ea, u8 laddr); |
| 98 | int (*get_laddr)(struct slim_controller *ctrl, |
| 99 | struct slim_eaddr *ea, u8 *laddr); |
| 100 | }; |
| 101 | |
| 102 | int slim_device_report_present(struct slim_controller *ctrl, |
| 103 | struct slim_eaddr *e_addr, u8 *laddr); |
| 104 | void slim_report_absent(struct slim_device *sbdev); |
| 105 | int slim_register_controller(struct slim_controller *ctrl); |
| 106 | int slim_unregister_controller(struct slim_controller *ctrl); |
| 107 | |
| 108 | #endif /* _LINUX_SLIMBUS_H */ |