1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2019 Ian Lepore <ian@freebsd.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #include "opt_platform.h" 30 31 #include <sys/param.h> 32 #include <sys/bus.h> 33 #include <sys/kernel.h> 34 #include <sys/module.h> 35 #include <sys/systm.h> 36 37 #include <dev/iicbus/iicbus.h> 38 #include <dev/iicbus/iiconf.h> 39 #include <dev/ofw/ofw_bus.h> 40 #include <dev/ofw/ofw_bus_subr.h> 41 #include <dev/ofw/openfirm.h> 42 43 #include "iicbus_if.h" 44 #include "iicmux_if.h" 45 46 47 static struct ofw_compat_data compat_data[] = { 48 {"nxp,pca9547", 1}, 49 {NULL, 0} 50 }; 51 IICBUS_FDT_PNP_INFO(compat_data); 52 53 #include <dev/iicbus/mux/iicmux.h> 54 55 struct pca9547_softc { 56 struct iicmux_softc mux; 57 device_t dev; 58 bool idle_disconnect; 59 }; 60 61 static int 62 pca9547_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd) 63 { 64 struct pca9547_softc *sc = device_get_softc(dev); 65 uint8_t busbits; 66 67 /* 68 * The iicmux caller ensures busidx is between 0 and the number of buses 69 * we passed to iicmux_init_softc(), no need for validation here. If 70 * the fdt data has the idle_disconnect property we idle the bus by 71 * selecting no downstream buses, otherwise we just leave the current 72 * bus active. The upper bits of control register 3 activate the 73 * downstream buses; bit 7 is the first bus, bit 6 the second, etc. 74 */ 75 if (busidx == IICMUX_SELECT_IDLE) { 76 if (sc->idle_disconnect) 77 busbits = 0; 78 else 79 return (0); 80 } else { 81 busbits = 0x8 | (busidx & 0x7); 82 } 83 84 /* 85 * We have to add the IIC_RECURSIVE flag because the iicmux core has 86 * already reserved the bus for us, and iicdev_writeto() is going to try 87 * to reserve it again, which is allowed with the recursive flag. 88 */ 89 90 return (iicdev_writeto(dev, busbits, NULL, 0, 91 rd->flags | IIC_RECURSIVE)); 92 } 93 94 static int 95 pca9547_probe(device_t dev) 96 { 97 if (!ofw_bus_status_okay(dev)) 98 return (ENXIO); 99 100 if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data) 101 return (ENXIO); 102 103 device_set_desc(dev, "PCA9547 IIC bus multiplexor"); 104 return (BUS_PROBE_DEFAULT); 105 } 106 107 static int 108 pca9547_attach(device_t dev) 109 { 110 struct pca9547_softc *sc; 111 phandle_t node; 112 int rv; 113 114 sc = device_get_softc(dev); 115 sc ->dev = dev; 116 117 node = ofw_bus_get_node(dev); 118 sc->idle_disconnect = OF_hasprop(node, "i2c-mux-idle-disconnect"); 119 120 rv = iicmux_attach(sc->dev, device_get_parent(dev), 8); 121 if (rv != 0) 122 return (rv); 123 rv = bus_generic_attach(dev); 124 125 return (rv); 126 } 127 128 static int 129 pca9547_detach(device_t dev) 130 { 131 int rv; 132 133 rv = iicmux_detach(dev); 134 if (rv != 0) 135 return (rv); 136 137 return (0); 138 } 139 140 static device_method_t pca9547_methods[] = { 141 /* device methods */ 142 DEVMETHOD(device_probe, pca9547_probe), 143 DEVMETHOD(device_attach, pca9547_attach), 144 DEVMETHOD(device_detach, pca9547_detach), 145 146 /* iicmux methods */ 147 DEVMETHOD(iicmux_bus_select, pca9547_bus_select), 148 149 DEVMETHOD_END 150 }; 151 152 DEFINE_CLASS_1(iicmux, pca9547_driver, pca9547_methods, 153 sizeof(struct pca9547_softc), iicmux_driver); 154 DRIVER_MODULE(pca_iicmux, iicbus, pca9547_driver, 0, 0); 155 DRIVER_MODULE(iicbus, iicmux, iicbus_driver, 0, 0); 156 DRIVER_MODULE(ofw_iicbus, iicmux, ofw_iicbus_driver, 0, 0); 157 MODULE_DEPEND(pca9547, iicmux, 1, 1, 1); 158 MODULE_DEPEND(pca9547, iicbus, 1, 1, 1); 159