FreeBSD/Linux Kernel Cross Reference
sys/dev/iicbus/mux/pca9547.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause
      *
      * Copyright (c) 2019 Ian Lepore <ian@freebsd.org>
      *
      * 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 <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_platform.h"
    
    #include <sys/param.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/systm.h>
    
    #include <dev/iicbus/iicbus.h>
    #include <dev/iicbus/iiconf.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    #include <dev/ofw/openfirm.h>
    
    #include "iicbus_if.h"
    #include "iicmux_if.h"
    
    
    static struct ofw_compat_data compat_data[] = {
            {"nxp,pca9547",         1},
            {NULL,                  0}
    };
    IICBUS_FDT_PNP_INFO(compat_data);
    
    #include <dev/iicbus/mux/iicmux.h>
    
    struct pca9547_softc {
            struct iicmux_softc mux;
            device_t        dev;
            bool idle_disconnect;
    };
    
    static int
    pca9547_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd)
    {
            struct pca9547_softc *sc = device_get_softc(dev);
            uint8_t busbits;
    
            /*
             * The iicmux caller ensures busidx is between 0 and the number of buses
             * we passed to iicmux_init_softc(), no need for validation here.  If
             * the fdt data has the idle_disconnect property we idle the bus by
             * selecting no downstream buses, otherwise we just leave the current
             * bus active.  The upper bits of control register 3 activate the
             * downstream buses; bit 7 is the first bus, bit 6 the second, etc.
             */
            if (busidx == IICMUX_SELECT_IDLE) {
                    if (sc->idle_disconnect)
                            busbits = 0;
                    else
                            return (0);
            } else {
                    busbits = 0x8 | (busidx & 0x7);
            }
    
            /*
             * We have to add the IIC_RECURSIVE flag because the iicmux core has
             * already reserved the bus for us, and iicdev_writeto() is going to try
             * to reserve it again, which is allowed with the recursive flag.
             */
    
            return (iicdev_writeto(dev, busbits, NULL, 0,
                rd->flags | IIC_RECURSIVE));
    }
    
    static int
    pca9547_probe(device_t dev)
    {
            if (!ofw_bus_status_okay(dev))
                   return (ENXIO);
   
           if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
                   return (ENXIO);
   
           device_set_desc(dev, "PCA9547 IIC bus multiplexor");
           return (BUS_PROBE_DEFAULT);
   }
   
   static int
   pca9547_attach(device_t dev)
   {
           struct pca9547_softc *sc;
           phandle_t node;
           int rv;
   
           sc = device_get_softc(dev);
           sc ->dev = dev;
   
           node = ofw_bus_get_node(dev);
           sc->idle_disconnect = OF_hasprop(node, "i2c-mux-idle-disconnect");
   
           rv = iicmux_attach(sc->dev, device_get_parent(dev), 8);
           if (rv != 0)
                   return (rv);
           rv = bus_generic_attach(dev);
   
           return (rv);
   }
   
   static int
   pca9547_detach(device_t dev)
   {
           int rv;
   
           rv = iicmux_detach(dev);
           if (rv != 0)
                   return (rv);
   
           return (0);
   }
   
   static device_method_t pca9547_methods[] = {
           /* device methods */
           DEVMETHOD(device_probe,                 pca9547_probe),
           DEVMETHOD(device_attach,                pca9547_attach),
           DEVMETHOD(device_detach,                pca9547_detach),
   
           /* iicmux methods */
           DEVMETHOD(iicmux_bus_select,            pca9547_bus_select),
   
           DEVMETHOD_END
   };
   
   DEFINE_CLASS_1(iicmux, pca9547_driver, pca9547_methods,
       sizeof(struct pca9547_softc), iicmux_driver);
   DRIVER_MODULE(pca_iicmux, iicbus, pca9547_driver, 0, 0);
   DRIVER_MODULE(iicbus, iicmux, iicbus_driver, 0, 0);
   DRIVER_MODULE(ofw_iicbus, iicmux, ofw_iicbus_driver, 0, 0);
   MODULE_DEPEND(pca9547, iicmux, 1, 1, 1);
   MODULE_DEPEND(pca9547, iicbus, 1, 1, 1);

Cache object: a063cd1068096b3ded7bd597a488413f