1*422d05daSIan Lepore /*- 2*422d05daSIan Lepore * SPDX-License-Identifier: BSD-2-Clause 3*422d05daSIan Lepore * 4*422d05daSIan Lepore * Copyright (c) 2019 Ian Lepore <ian@freebsd.org> 5*422d05daSIan Lepore * 6*422d05daSIan Lepore * Redistribution and use in source and binary forms, with or without 7*422d05daSIan Lepore * modification, are permitted provided that the following conditions 8*422d05daSIan Lepore * are met: 9*422d05daSIan Lepore * 1. Redistributions of source code must retain the above copyright 10*422d05daSIan Lepore * notice, this list of conditions and the following disclaimer. 11*422d05daSIan Lepore * 2. Redistributions in binary form must reproduce the above copyright 12*422d05daSIan Lepore * notice, this list of conditions and the following disclaimer in the 13*422d05daSIan Lepore * documentation and/or other materials provided with the distribution. 14*422d05daSIan Lepore * 15*422d05daSIan Lepore * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16*422d05daSIan Lepore * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17*422d05daSIan Lepore * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18*422d05daSIan Lepore * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19*422d05daSIan Lepore * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20*422d05daSIan Lepore * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21*422d05daSIan Lepore * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22*422d05daSIan Lepore * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23*422d05daSIan Lepore * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24*422d05daSIan Lepore * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25*422d05daSIan Lepore * SUCH DAMAGE. 26*422d05daSIan Lepore */ 27*422d05daSIan Lepore 28*422d05daSIan Lepore #ifndef __IICMUX_H 29*422d05daSIan Lepore #define __IICMUX_H 30*422d05daSIan Lepore 31*422d05daSIan Lepore #define IICMUX_MAX_BUSES 16 /* More than any available mux chip. */ 32*422d05daSIan Lepore 33*422d05daSIan Lepore /* 34*422d05daSIan Lepore * IICMUX_SELECT_IDLE instructs the mux hardware driver to do whatever it is 35*422d05daSIan Lepore * configured to do when the downstream buses are idle. Hardware has varying 36*422d05daSIan Lepore * capabilities; it may disconnect all downstream buses, or connect a specific 37*422d05daSIan Lepore * bus, or just leave whatever bus was last used connected. Hardware which is 38*422d05daSIan Lepore * capable of various choices will have some mechanism to configure the choice 39*422d05daSIan Lepore * which is handled outside of the iicmux framework. 40*422d05daSIan Lepore */ 41*422d05daSIan Lepore #define IICMUX_SELECT_IDLE (-1) 42*422d05daSIan Lepore 43*422d05daSIan Lepore /* 44*422d05daSIan Lepore * The iicmux softc; chip drivers should embed one of these as the first member 45*422d05daSIan Lepore * variable of their own softc struct, and must call iicmux_attach() to 46*422d05daSIan Lepore * initialize it before calling any other iicmux functions. 47*422d05daSIan Lepore */ 48*422d05daSIan Lepore struct iicmux_softc { 49*422d05daSIan Lepore device_t busdev; /* Upstream i2c bus (may not be our parent). */ 50*422d05daSIan Lepore device_t dev; /* Ourself. */ 51*422d05daSIan Lepore int maxbus; /* Index of highest populated busdevs slot. */ 52*422d05daSIan Lepore int numbuses; /* Number of buses supported by the chip. */ 53*422d05daSIan Lepore int debugmux; /* Write debug messages when > 0. */ 54*422d05daSIan Lepore device_t childdevs[IICMUX_MAX_BUSES]; /* Child bus instances. */ 55*422d05daSIan Lepore #ifdef FDT 56*422d05daSIan Lepore phandle_t childnodes[IICMUX_MAX_BUSES]; /* Child bus fdt nodes. */ 57*422d05daSIan Lepore #endif 58*422d05daSIan Lepore }; 59*422d05daSIan Lepore 60*422d05daSIan Lepore DECLARE_CLASS(iicmux_driver); 61*422d05daSIan Lepore 62*422d05daSIan Lepore /* 63*422d05daSIan Lepore * Helpers to call from attach/detach functions of chip-specific drivers. 64*422d05daSIan Lepore * 65*422d05daSIan Lepore * The iicmux_attach() function initializes the core driver's portion of the 66*422d05daSIan Lepore * softc, and creates child iicbus instances for any children it can identify 67*422d05daSIan Lepore * using hints and FDT data. If a chip driver does its own device_add_child() 68*422d05daSIan Lepore * calls to add other downstream buses that participate in the mux switching, it 69*422d05daSIan Lepore * must call iicmux_add_child() to inform the core driver of the downstream 70*422d05daSIan Lepore * busidx<->device_t relationship. 71*422d05daSIan Lepore */ 72*422d05daSIan Lepore int iicmux_add_child(device_t dev, device_t child, int busidx); 73*422d05daSIan Lepore int iicmux_attach(device_t dev, device_t busdev, int numbuses); 74*422d05daSIan Lepore int iicmux_detach(device_t dev); 75*422d05daSIan Lepore 76*422d05daSIan Lepore #endif 77