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-rw-r--r--drivers/slimbus/slimbus.h261
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 */