4cd6abddcd
Document locking semantics. Differential Revision: https://reviews.freebsd.org/D2744 Reviewed by: jah, kib Approved by: kib
120 lines
4.1 KiB
C
120 lines
4.1 KiB
C
/*
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* Copyright (c) 2014 The DragonFly Project. All rights reserved.
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*
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* This code is derived from software contributed to The DragonFly Project
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* by Matthew Dillon <dillon@backplane.com> and was subsequently ported
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* to FreeBSD by Michael Gmelin <freebsd@grem.de>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name of The DragonFly Project nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific, prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _BUS_SMBUS_INTELGEN4_IG4_VAR_H_
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#define _BUS_SMBUS_INTELGEN4_IG4_VAR_H_
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#include "bus_if.h"
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#include "device_if.h"
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#include "pci_if.h"
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#include "smbus_if.h"
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#define IG4_RBUFSIZE 128
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#define IG4_RBUFMASK (IG4_RBUFSIZE - 1)
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enum ig4_op { IG4_IDLE, IG4_READ, IG4_WRITE };
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struct ig4iic_softc {
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device_t dev;
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struct intr_config_hook enum_hook;
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device_t smb;
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struct resource *regs_res;
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int regs_rid;
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struct resource *intr_res;
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int intr_rid;
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void *intr_handle;
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int intr_type;
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enum ig4_op op;
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int cmd;
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int rnext;
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int rpos;
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char rbuf[IG4_RBUFSIZE];
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int error;
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uint8_t last_slave;
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int pci_attached : 1;
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int use_10bit : 1;
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int slave_valid : 1;
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int read_started : 1;
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int write_started : 1;
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/*
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* Locking semantics:
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*
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* Functions implementing the smbus interface that interact
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* with the controller acquire an exclusive lock on call_lock
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* to prevent interleaving of calls to the interface and a lock on
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* io_lock right afterwards, to synchronize controller I/O activity.
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*
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* The interrupt handler can only read data while no ig4iic_smb_* call
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* is in progress or while io_lock is dropped during mtx_sleep in
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* wait_status and set_controller. It is safe to drop io_lock in those
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* places, because the interrupt handler only accesses those registers:
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*
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* - IG4_REG_I2C_STA (I2C Status)
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* - IG4_REG_DATA_CMD (Data Buffer and Command)
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* - IG4_REG_CLR_INTR (Clear Interrupt)
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*
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* Locking outside of those places is required to make the content
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* of rpos/rnext predictable (e.g. whenever data_read is called and in
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* smb_transaction).
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*/
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struct sx call_lock;
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struct mtx io_lock;
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};
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typedef struct ig4iic_softc ig4iic_softc_t;
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/* Attach/Detach called from ig4iic_pci_*() */
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int ig4iic_attach(ig4iic_softc_t *sc);
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int ig4iic_detach(ig4iic_softc_t *sc);
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/* SMBus methods */
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extern smbus_callback_t ig4iic_smb_callback;
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extern smbus_quick_t ig4iic_smb_quick;
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extern smbus_sendb_t ig4iic_smb_sendb;
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extern smbus_recvb_t ig4iic_smb_recvb;
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extern smbus_writeb_t ig4iic_smb_writeb;
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extern smbus_writew_t ig4iic_smb_writew;
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extern smbus_readb_t ig4iic_smb_readb;
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extern smbus_readw_t ig4iic_smb_readw;
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extern smbus_pcall_t ig4iic_smb_pcall;
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extern smbus_bwrite_t ig4iic_smb_bwrite;
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extern smbus_bread_t ig4iic_smb_bread;
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extern smbus_trans_t ig4iic_smb_trans;
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#endif
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