/*- * 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 __FBSDID("$FreeBSD$"); #include "opt_platform.h" #include #include #include #include #include #include #include #include "iicbus_if.h" #include "iicmux_if.h" static struct chip_info { const char *partname; const char *description; int numchannels; } chip_infos[] = { {"ltc4305", "LTC4305 I2C Mux", 2}, {"ltc4306", "LTC4306 I2C Mux", 4}, }; #define CHIP_NONE (-1) #define CHIP_LTC4305 0 #define CHIP_LTC4306 1 #ifdef FDT #include #include #include static struct ofw_compat_data compat_data[] = { {"lltc,ltc4305", CHIP_LTC4305}, {"lltc,ltc4306", CHIP_LTC4306}, {NULL, CHIP_NONE} }; IICBUS_FDT_PNP_INFO(compat_data); #endif #include struct ltc430x_softc { struct iicmux_softc mux; bool idle_disconnect; }; /* * The datasheet doesn't name the registers, it calls them control register 0-3. */ #define LTC430X_CTLREG_0 0 #define LTC430X_CTLREG_1 1 #define LTC430X_CTLREG_2 2 #define LTC430X_CR2_ENABLE_MW (1u << 3) /* Enable mass write address. */ #define LTC430X_CTLREG_3 3 static int ltc430x_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd) { struct ltc430x_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 = 1u << (7 - busidx); } /* * 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, LTC430X_CTLREG_3, &busbits, sizeof(busbits), rd->flags | IIC_RECURSIVE)); } static int ltc430x_find_chiptype(device_t dev) { #ifdef FDT return (ofw_bus_search_compatible(dev, compat_data)->ocd_data); #else const char *type; int i; if (resource_string_value(device_get_name(dev), device_get_unit(dev), "chip_type", &type) == 0) { for (i = 0; i < nitems(chip_infos); ++i) { if (strcasecmp(type, chip_infos[i].partname) == 0) { return (i); } } } return (CHIP_NONE); #endif } static int ltc430x_probe(device_t dev) { int type; #ifdef FDT if (!ofw_bus_status_okay(dev)) return (ENXIO); #endif type = ltc430x_find_chiptype(dev); if (type == CHIP_NONE) return (ENXIO); device_set_desc(dev, chip_infos[type].description); return (BUS_PROBE_DEFAULT); } static int ltc430x_attach(device_t dev) { struct ltc430x_softc *sc __unused; int chip, err, numchan, val; uint8_t busbits, ctlreg2; sc = device_get_softc(dev); busbits = 0; ctlreg2 = LTC430X_CR2_ENABLE_MW; /* * Check for the idle-disconnect and ctlreg2 options, first in FDT data, * then allow them to be overriden by hints data. */ #ifdef FDT phandle_t node; node = ofw_bus_get_node(dev); sc->idle_disconnect = OF_hasprop(node, "i2c-mux-idle-disconnect"); if (OF_getprop(node, "freebsd,ctlreg2", &val, sizeof(val)) > 0) { ctlreg2 = val; } #endif if (resource_int_value(device_get_name(dev), device_get_unit(dev), "idle_disconnect", &val) == 0) { sc->idle_disconnect = val; } if (resource_int_value(device_get_name(dev), device_get_unit(dev), "ctlreg2", &val) == 0) { ctlreg2 = val; } /* We found the chip type when probing, so now it "can't fail". */ if ((chip = ltc430x_find_chiptype(dev)) == CHIP_NONE) { device_printf(dev, "impossible: can't identify chip type\n"); return (ENXIO); } numchan = chip_infos[chip].numchannels; /* Set control reg 2 with configured (or default) values. */ iicdev_writeto(dev, LTC430X_CTLREG_2, &ctlreg2, sizeof(ctlreg2), IIC_WAIT); /* If configured for idle-disconnect, ensure we start disconnected. */ if (sc->idle_disconnect) { iicdev_writeto(dev, LTC430X_CTLREG_3, &busbits, sizeof(busbits), IIC_WAIT); } /* * Invoke the iicmux framework's attach code, and if it succeeds, invoke * the probe and attach code of any child iicbus instances it added. */ if ((err = iicmux_attach(dev, device_get_parent(dev), numchan)) == 0) bus_generic_attach(dev); return (err); } static int ltc430x_detach(device_t dev) { int err; if ((err = iicmux_detach(dev)) != 0) return (err); return (0); } static device_method_t ltc430x_methods[] = { /* device methods */ DEVMETHOD(device_probe, ltc430x_probe), DEVMETHOD(device_attach, ltc430x_attach), DEVMETHOD(device_detach, ltc430x_detach), /* iicmux methods */ DEVMETHOD(iicmux_bus_select, ltc430x_bus_select), DEVMETHOD_END }; DEFINE_CLASS_1(ltc430x, ltc430x_driver, ltc430x_methods, sizeof(struct ltc430x_softc), iicmux_driver); DRIVER_MODULE(ltc430x, iicbus, ltc430x_driver, 0, 0); #ifdef FDT DRIVER_MODULE(ofw_iicbus, ltc430x, ofw_iicbus_driver, 0, 0); #else DRIVER_MODULE(iicbus, ltc430x, iicbus_driver, 0, 0); #endif MODULE_DEPEND(ltc430x, iicmux, 1, 1, 1); MODULE_DEPEND(ltc430x, iicbus, 1, 1, 1);