/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2019 Ian Lepore * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include "opt_platform.h" #include #include #include #include #include #ifdef FDT #include #include #include #endif #include #include "iicbus_if.h" #include "iicmux_if.h" #include "iicmux.h" /*------------------------------------------------------------------------------ * iicbus methods, called by the iicbus functions in iiconf.c. * * All these functions return an IIC adapter-layer error code (because we are * pretending to be a host bridge/i2c controller). Standard errno values * returned from these must be encoded using iic2errno(). *----------------------------------------------------------------------------*/ static int iicmux_callback(device_t dev, int index, caddr_t data) { struct iicmux_softc *sc = device_get_softc(dev); struct iic_reqbus_data *rd; int err, i; /* If it's not one of the operations we know about, bail early. */ if (index != IIC_REQUEST_BUS && index != IIC_RELEASE_BUS) return (iic2errno(EOPNOTSUPP)); /* * Ensure that the data passed to us includes the device_t of the child * bus and device. If missing, someone bypassed iicbus_request_bus() * and called this method directly using the old calling standard. If * present, find the index of the child bus that called us. */ rd = (struct iic_reqbus_data *)data; if (!(rd->flags & IIC_REQBUS_DEV)) return (iic2errno(EINVAL)); for (i = 0; i <= sc->maxbus && sc->childdevs[i] != rd->bus; ++i) continue; if (i > sc->maxbus) return (iic2errno(ENOENT)); /* * If the operation is a release it "cannot fail". Idle the downstream * bus, then release exclusive use of the upstream bus, and we're done. */ if (index == IIC_RELEASE_BUS) { if (sc->debugmux > 0) { device_printf(dev, "idle the bus for %s on bus %s\n", device_get_nameunit(rd->dev), device_get_nameunit(rd->bus)); } IICMUX_BUS_SELECT(dev, IICMUX_SELECT_IDLE, rd); iicbus_release_bus(sc->busdev, dev); return (IIC_NOERR); } if (sc->debugmux > 0) { device_printf(dev, "select bus idx %d for %s on bus %s\n", i, device_get_nameunit(rd->dev), device_get_nameunit(rd->bus)); } /* * The operation is a request for exclusive use. First we have to * request exclusive use of our upstream bus. If multiple slave devices * from our different child buses attempt to do IO at the same time, * this is what ensures that they don't switch the bus out from under * each other. The first one in proceeds and others wait here (or get an * EWOULDBLOCK return if they're using IIC_DONTWAIT). */ if ((err = iicbus_request_bus(sc->busdev, dev, rd->flags)) != 0) return (err); /* Already an IIC error code. */ /* * Now that we own exclusive use of the upstream bus, connect it to the * downstream bus where the request came from. */ if ((err = IICMUX_BUS_SELECT(dev, i, rd)) != 0) iicbus_release_bus(sc->busdev, dev); return (err); } static u_int iicmux_get_frequency(device_t dev, u_char speed) { struct iicmux_softc *sc = device_get_softc(dev); return (IICBUS_GET_FREQUENCY(sc->busdev, speed)); } #ifdef FDT static phandle_t iicmux_get_node(device_t dev, device_t child) { struct iicmux_softc *sc = device_get_softc(dev); int i; for (i = 0; i <= sc->maxbus; ++i) { if (sc->childdevs[i] == child) return (sc->childnodes[i]); } return (0); /* null handle */ } #endif static int iicmux_intr(device_t dev, int event, char *buf) { struct iicmux_softc *sc = device_get_softc(dev); /* XXX iicbus_intr() in iiconf.c should return status. */ iicbus_intr(sc->busdev, event, buf); return (0); } static int iicmux_read(device_t dev, char *buf, int len, int *bytes, int last, int delay) { struct iicmux_softc *sc = device_get_softc(dev); return (iicbus_read(sc->busdev, buf, len, bytes, last, delay)); } static int iicmux_repeated_start(device_t dev, u_char slave, int timeout) { struct iicmux_softc *sc = device_get_softc(dev); return (iicbus_repeated_start(sc->busdev, slave, timeout)); } static int iicmux_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) { struct iicmux_softc *sc = device_get_softc(dev); return (iicbus_reset(sc->busdev, speed, addr, oldaddr)); } static int iicmux_start(device_t dev, u_char slave, int timeout) { struct iicmux_softc *sc = device_get_softc(dev); return (iicbus_start(sc->busdev, slave, timeout)); } static int iicmux_stop(device_t dev) { struct iicmux_softc *sc = device_get_softc(dev); return (iicbus_stop(sc->busdev)); } static int iicmux_transfer( device_t dev, struct iic_msg *msgs, uint32_t nmsgs) { struct iicmux_softc *sc = device_get_softc(dev); return (iicbus_transfer(sc->busdev, msgs, nmsgs)); } static int iicmux_write(device_t dev, const char *buf, int len, int *bytes, int timeout) { struct iicmux_softc *sc = device_get_softc(dev); return (iicbus_write(sc->busdev, buf, len, bytes, timeout)); } /*------------------------------------------------------------------------------ * iicmux helper functions, called by hardware-specific drivers. * All these functions return a standard errno value. *----------------------------------------------------------------------------*/ int iicmux_add_child(device_t dev, device_t child, int busidx) { struct iicmux_softc *sc = device_get_softc(dev); if (busidx >= sc->numbuses) { device_printf(dev, "iicmux_add_child: bus idx %d too big", busidx); return (EINVAL); } if (sc->childdevs[busidx] != NULL) { device_printf(dev, "iicmux_add_child: bus idx %d already added", busidx); return (EINVAL); } sc->childdevs[busidx] = child; if (sc->maxbus < busidx) sc->maxbus = busidx; return (0); } static int iicmux_attach_children(struct iicmux_softc *sc) { int i; #ifdef FDT phandle_t child, node, parent; pcell_t idx; /* * Find our FDT node. Child nodes within our node will become our * iicbus children. */ if((node = ofw_bus_get_node(sc->dev)) == 0) { device_printf(sc->dev, "cannot find FDT node\n"); return (ENOENT); } /* * First we have to see if there is a child node named "i2c-mux". If it * exists, all children of that node are buses, else all children of the * device node are buses. */ if ((parent = ofw_bus_find_child(node, "i2c-mux")) == 0) parent = node; /* * Attach the children represented in the device tree. */ for (child = OF_child(parent); child != 0; child = OF_peer(child)) { if (OF_getencprop(child, "reg", &idx, sizeof(idx)) == -1) { device_printf(sc->dev, "child bus missing required 'reg' property\n"); continue; } if (idx >= sc->numbuses) { device_printf(sc->dev, "child bus 'reg' property %d exceeds the number " "of buses supported by the device (%d)\n", idx, sc->numbuses); continue; } sc->childdevs[idx] = device_add_child(sc->dev, "iicbus", -1); sc->childnodes[idx] = child; if (sc->maxbus < (int)idx) sc->maxbus = idx; } /* If we configured anything using FDT data, we're done. */ if (sc->maxbus >= 0) return (0); #endif /* FDT */ /* * If we make it to here, we didn't add any children based on FDT data. * Add an iicbus child for every downstream bus supported by the mux. */ for (i = 0; i < sc->numbuses; ++i) { sc->childdevs[i] = device_add_child(sc->dev, "iicbus", -1); sc->maxbus = i; } return (0); } int iicmux_attach(device_t dev, device_t busdev, int numbuses) { struct iicmux_softc *sc = device_get_softc(dev); int err; if (numbuses >= IICMUX_MAX_BUSES) { device_printf(dev, "iicmux_attach: numbuses %d > max %d\n", numbuses, IICMUX_MAX_BUSES); return (EINVAL); } sc->dev = dev; sc->busdev = busdev; sc->maxbus = -1; sc->numbuses = numbuses; if ((err = iicmux_attach_children(sc)) != 0) return (err); SYSCTL_ADD_UINT(device_get_sysctl_ctx(sc->dev), SYSCTL_CHILDREN(device_get_sysctl_tree(sc->dev)), OID_AUTO, "debugmux", CTLFLAG_RWTUN, &sc->debugmux, 0, "debug mux operations"); return (0); } int iicmux_detach(device_t dev) { struct iicmux_softc *sc = device_get_softc(dev); int err, i; /* Delete only the children we added in iicmux_add* functions. */ for (i = 0; i <= sc->maxbus; ++i) { if (sc->childdevs[i] == NULL) continue; if ((err = device_delete_child(dev, sc->childdevs[i])) != 0) return (err); sc->childdevs[i] = NULL; } return (0); } static device_method_t iicmux_methods [] = { /* iicbus_if methods */ DEVMETHOD(iicbus_intr, iicmux_intr), DEVMETHOD(iicbus_callback, iicmux_callback), DEVMETHOD(iicbus_repeated_start, iicmux_repeated_start), DEVMETHOD(iicbus_start, iicmux_start), DEVMETHOD(iicbus_stop, iicmux_stop), DEVMETHOD(iicbus_read, iicmux_read), DEVMETHOD(iicbus_write, iicmux_write), DEVMETHOD(iicbus_reset, iicmux_reset), DEVMETHOD(iicbus_transfer, iicmux_transfer), DEVMETHOD(iicbus_get_frequency, iicmux_get_frequency), #ifdef FDT /* ofwbus_if methods */ DEVMETHOD(ofw_bus_get_node, iicmux_get_node), #endif DEVMETHOD_END }; static int iicmux_modevent(module_t mod, int type, void *unused) { switch (type) { case MOD_LOAD: return 0; case MOD_UNLOAD: return 0; } return EINVAL; } static moduledata_t iicmux_mod = { "iicmux", iicmux_modevent, 0 }; DEFINE_CLASS_0(iicmux, iicmux_driver, iicmux_methods, sizeof(struct iicmux_softc)); DECLARE_MODULE(iicmux, iicmux_mod, SI_SUB_DRIVERS, SI_ORDER_ANY); MODULE_VERSION(iicmux, 1); MODULE_DEPEND(iicmux, iicbus, 1, 1, 1);