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Diffstat (limited to 'drivers/slimbus/slimbus.h')
| -rw-r--r-- | drivers/slimbus/slimbus.h | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/slimbus/slimbus.h b/drivers/slimbus/slimbus.h new file mode 100644 index 000000000000..79f8e05d92dd --- /dev/null +++ b/drivers/slimbus/slimbus.h @@ -0,0 +1,261 @@ +// 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/completion.h> +#include <linux/slimbus.h> + +/* Standard values per SLIMbus spec needed by controllers and devices */ +#define SLIM_CL_PER_SUPERFRAME 6144 +#define SLIM_CL_PER_SUPERFRAME_DIV8 (SLIM_CL_PER_SUPERFRAME >> 3) + +/* SLIMbus message types. Related to interpretation of message code. */ +#define SLIM_MSG_MT_CORE 0x0 + +/* + * SLIM Broadcast header format + * BYTE 0: MT[7:5] RL[4:0] + * BYTE 1: RSVD[7] MC[6:0] + * BYTE 2: RSVD[7:6] DT[5:4] PI[3:0] + */ +#define SLIM_MSG_MT_MASK GENMASK(2, 0) +#define SLIM_MSG_MT_SHIFT 5 +#define SLIM_MSG_RL_MASK GENMASK(4, 0) +#define SLIM_MSG_RL_SHIFT 0 +#define SLIM_MSG_MC_MASK GENMASK(6, 0) +#define SLIM_MSG_MC_SHIFT 0 +#define SLIM_MSG_DT_MASK GENMASK(1, 0) +#define SLIM_MSG_DT_SHIFT 4 + +#define SLIM_HEADER_GET_MT(b) ((b >> SLIM_MSG_MT_SHIFT) & SLIM_MSG_MT_MASK) +#define SLIM_HEADER_GET_RL(b) ((b >> SLIM_MSG_RL_SHIFT) & SLIM_MSG_RL_MASK) +#define SLIM_HEADER_GET_MC(b) ((b >> SLIM_MSG_MC_SHIFT) & SLIM_MSG_MC_MASK) +#define SLIM_HEADER_GET_DT(b) ((b >> SLIM_MSG_DT_SHIFT) & SLIM_MSG_DT_MASK) + +/* Device management messages used by this framework */ +#define SLIM_MSG_MC_REPORT_PRESENT 0x1 +#define SLIM_MSG_MC_ASSIGN_LOGICAL_ADDRESS 0x2 +#define SLIM_MSG_MC_REPORT_ABSENT 0xF + +/* Clock pause Reconfiguration messages */ +#define SLIM_MSG_MC_BEGIN_RECONFIGURATION 0x40 +#define SLIM_MSG_MC_NEXT_PAUSE_CLOCK 0x4A +#define SLIM_MSG_MC_RECONFIGURE_NOW 0x5F + +/* Clock pause values per SLIMbus spec */ +#define SLIM_CLK_FAST 0 +#define SLIM_CLK_CONST_PHASE 1 +#define SLIM_CLK_UNSPECIFIED 2 + +/* Destination type Values */ +#define SLIM_MSG_DEST_LOGICALADDR 0 +#define SLIM_MSG_DEST_ENUMADDR 1 +#define SLIM_MSG_DEST_BROADCAST 3 + +/* 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 + +#define SLIM_MAX_TIDS 256 +/** + * 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_msg_txn - Message to be sent by the controller. + * This structure has packet header, + * payload and buffer to be filled (if any) + * @rl: Header field. remaining length. + * @mt: Header field. Message type. + * @mc: Header field. LSB is message code for type mt. + * @dt: Header field. Destination type. + * @ec: Element code. Used for elemental access APIs. + * @tid: Transaction ID. Used for messages expecting response. + * (relevant for message-codes involving read operation) + * @la: Logical address of the device this message is going to. + * (Not used when destination type is broadcast.) + * @msg: Elemental access message to be read/written + * @comp: completion if read/write is synchronous, used internally + * for tid based transactions. + */ +struct slim_msg_txn { + u8 rl; + u8 mt; + u8 mc; + u8 dt; + u16 ec; + u8 tid; + u8 la; + struct slim_val_inf *msg; + struct completion *comp; +}; + +/* Frequently used message transaction structures */ +#define DEFINE_SLIM_LDEST_TXN(name, mc, rl, la, msg) \ + struct slim_msg_txn name = { rl, 0, mc, SLIM_MSG_DEST_LOGICALADDR, 0,\ + 0, la, msg, } + +#define DEFINE_SLIM_BCAST_TXN(name, mc, rl, la, msg) \ + struct slim_msg_txn name = { rl, 0, mc, SLIM_MSG_DEST_BROADCAST, 0,\ + 0, la, msg, } + +#define DEFINE_SLIM_EDEST_TXN(name, mc, rl, la, msg) \ + struct slim_msg_txn name = { rl, 0, mc, SLIM_MSG_DEST_ENUMADDR, 0,\ + 0, la, msg, } +/** + * enum slim_clk_state: SLIMbus controller's clock state used internally for + * maintaining current clock state. + * @SLIM_CLK_ACTIVE: SLIMbus clock is active + * @SLIM_CLK_ENTERING_PAUSE: SLIMbus clock pause sequence is being sent on the + * bus. If this succeeds, state changes to SLIM_CLK_PAUSED. If the + * transition fails, state changes back to SLIM_CLK_ACTIVE + * @SLIM_CLK_PAUSED: SLIMbus controller clock has paused. + */ +enum slim_clk_state { + SLIM_CLK_ACTIVE, + SLIM_CLK_ENTERING_PAUSE, + SLIM_CLK_PAUSED, +}; + +/** + * struct slim_sched: Framework uses this structure internally for scheduling. + * @clk_state: Controller's clock state from enum slim_clk_state + * @pause_comp: Signals completion of clock pause sequence. This is useful when + * client tries to call SLIMbus transaction when controller is entering + * clock pause. + * @m_reconf: This mutex is held until current reconfiguration (data channel + * scheduling, message bandwidth reservation) is done. Message APIs can + * use the bus concurrently when this mutex is held since elemental access + * messages can be sent on the bus when reconfiguration is in progress. + */ +struct slim_sched { + enum slim_clk_state clk_state; + struct completion pause_comp; + struct mutex m_reconf; +}; + +/** + * 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 + * @sched: scheduler structure used by the controller + * @xfer_msg: Transfer a message on this controller (this can be a broadcast + * control/status message like data channel setup, or a unicast message + * like value element read/write. + * @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. + * @wakeup: This function pointer implements controller-specific procedure + * to wake it up from clock-pause. Framework will call this to bring + * the controller out of clock pause. + * + * '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; + struct slim_sched sched; + int (*xfer_msg)(struct slim_controller *ctrl, + struct slim_msg_txn *tx); + 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 (*wakeup)(struct slim_controller *ctrl); +}; + +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); +void slim_msg_response(struct slim_controller *ctrl, u8 *reply, u8 tid, u8 l); +int slim_do_transfer(struct slim_controller *ctrl, struct slim_msg_txn *txn); +int slim_ctrl_clk_pause(struct slim_controller *ctrl, bool wakeup, u8 restart); + +static inline bool slim_tid_txn(u8 mt, u8 mc) +{ + return (mt == SLIM_MSG_MT_CORE && + (mc == SLIM_MSG_MC_REQUEST_INFORMATION || + mc == SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION || + mc == SLIM_MSG_MC_REQUEST_VALUE || + mc == SLIM_MSG_MC_REQUEST_CLEAR_INFORMATION)); +} + +static inline bool slim_ec_txn(u8 mt, u8 mc) +{ + return (mt == SLIM_MSG_MT_CORE && + ((mc >= SLIM_MSG_MC_REQUEST_INFORMATION && + mc <= SLIM_MSG_MC_REPORT_INFORMATION) || + (mc >= SLIM_MSG_MC_REQUEST_VALUE && + mc <= SLIM_MSG_MC_CHANGE_VALUE))); +} +#endif /* _LINUX_SLIMBUS_H */ |