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 __FBSDID("$FreeBSD$"); 30 31 #include "opt_platform.h" 32 33 #include <sys/param.h> 34 #include <sys/bus.h> 35 #include <sys/kernel.h> 36 #include <sys/module.h> 37 #include <sys/systm.h> 38 39 #include <dev/iicbus/iicbus.h> 40 #include <dev/iicbus/iiconf.h> 41 #include <dev/ofw/ofw_bus.h> 42 #include <dev/ofw/ofw_bus_subr.h> 43 #include <dev/ofw/openfirm.h> 44 45 #include "iicbus_if.h" 46 #include "iicmux_if.h" 47 48 49 static struct ofw_compat_data compat_data[] = { 50 {"nxp,pca9547", 1}, 51 {NULL, 0} 52 }; 53 54 #include <dev/iicbus/mux/iicmux.h> 55 56 struct pca9547_softc { 57 struct iicmux_softc mux; 58 device_t dev; 59 bool idle_disconnect; 60 }; 61 62 static int 63 pca9547_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd) 64 { 65 struct pca9547_softc *sc = device_get_softc(dev); 66 uint8_t busbits; 67 68 /* 69 * The iicmux caller ensures busidx is between 0 and the number of buses 70 * we passed to iicmux_init_softc(), no need for validation here. If 71 * the fdt data has the idle_disconnect property we idle the bus by 72 * selecting no downstream buses, otherwise we just leave the current 73 * bus active. The upper bits of control register 3 activate the 74 * downstream buses; bit 7 is the first bus, bit 6 the second, etc. 75 */ 76 if (busidx == IICMUX_SELECT_IDLE) { 77 if (sc->idle_disconnect) 78 busbits = 0; 79 else 80 return (0); 81 } else { 82 busbits = 0x8 | (busidx & 0x7); 83 } 84 85 /* 86 * We have to add the IIC_RECURSIVE flag because the iicmux core has 87 * already reserved the bus for us, and iicdev_writeto() is going to try 88 * to reserve it again, which is allowed with the recursive flag. 89 */ 90 91 return (iicdev_writeto(dev, busbits, NULL, 0, 92 rd->flags | IIC_RECURSIVE)); 93 } 94 95 static int 96 pca9547_probe(device_t dev) 97 { 98 if (!ofw_bus_status_okay(dev)) 99 return (ENXIO); 100 101 if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data) 102 return (ENXIO); 103 104 device_set_desc(dev, "PCA9547 IIC bus multiplexor"); 105 return (BUS_PROBE_DEFAULT); 106 } 107 108 static int 109 pca9547_attach(device_t dev) 110 { 111 struct pca9547_softc *sc; 112 phandle_t node; 113 int rv; 114 115 sc = device_get_softc(dev); 116 sc ->dev = dev; 117 118 node = ofw_bus_get_node(dev); 119 sc->idle_disconnect = OF_hasprop(node, "i2c-mux-idle-disconnect"); 120 121 rv = iicmux_attach(sc->dev, device_get_parent(dev), 8); 122 if (rv != 0) 123 return (rv); 124 rv = bus_generic_attach(dev); 125 126 return (rv); 127 } 128 129 static int 130 pca9547_detach(device_t dev) 131 { 132 int rv; 133 134 rv = iicmux_detach(dev); 135 if (rv != 0) 136 return (rv); 137 138 return (0); 139 } 140 141 static device_method_t pca9547_methods[] = { 142 /* device methods */ 143 DEVMETHOD(device_probe, pca9547_probe), 144 DEVMETHOD(device_attach, pca9547_attach), 145 DEVMETHOD(device_detach, pca9547_detach), 146 147 /* iicmux methods */ 148 DEVMETHOD(iicmux_bus_select, pca9547_bus_select), 149 150 DEVMETHOD_END 151 }; 152 153 static devclass_t pca9547_devclass; 154 DEFINE_CLASS_1(iicmux, pca9547_driver, pca9547_methods, 155 sizeof(struct pca9547_softc), iicmux_driver); 156 DRIVER_MODULE(pca_iicmux, iicbus, pca9547_driver, pca9547_devclass, 0, 0); 157 IICBUS_FDT_PNP_INFO(compat_data); 158 DRIVER_MODULE(iicbus, iicmux, iicbus_driver, iicbus_devclass, 0, 0); 159 DRIVER_MODULE(ofw_iicbus, iicmux, ofw_iicbus_driver, ofw_iicbus_devclass, 160 0, 0); 161 MODULE_DEPEND(pca9547, iicmux, 1, 1, 1); 162 MODULE_DEPEND(pca9547, iicbus, 1, 1, 1); 163