/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) Andriy Gapon * * 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 #include #include #include #include #ifdef FDT #include #include #endif /* * Driver for PCF8591 I2C 8-bit ADC and DAC. */ #define CTRL_CH_SELECT_MASK 0x03 #define CTRL_AUTOINC_EN 0x04 #define CTRL_CH_CONFIG_MASK 0x30 #define CTRL_CH_CONFIG_4_SINGLE 0x00 #define CTRL_CH_CONFIG_3_DIFF 0x10 #define CTRL_CH_CONFIG_2_SINGLE_1_DIFF 0x20 #define CTRL_CH_CONFIG_2_DIFF 0x30 #define CTRL_OUTPUT_EN 0x40 struct pcf8591_softc { device_t sc_dev; int sc_ch_count; uint8_t sc_addr; uint8_t sc_cfg; uint8_t sc_output; }; #ifdef FDT static struct ofw_compat_data compat_data[] = { { "nxp,pcf8591", true }, { NULL, false } }; #endif static int pcf8591_set_config(device_t dev) { struct iic_msg msg; uint8_t data[2]; struct pcf8591_softc *sc; int error; sc = device_get_softc(dev); data[0] = sc->sc_cfg; data[1] = sc->sc_output; msg.slave = sc->sc_addr; msg.flags = IIC_M_WR; msg.len = nitems(data); msg.buf = data; error = iicbus_transfer_excl(dev, &msg, 1, IIC_INTRWAIT); return (error); } static int pcf8591_get_reading(device_t dev, uint8_t *reading) { struct iic_msg msg; struct pcf8591_softc *sc; int error; sc = device_get_softc(dev); msg.slave = sc->sc_addr; msg.flags = IIC_M_RD; msg.len = 1; msg.buf = reading; error = iicbus_transfer_excl(dev, &msg, 1, IIC_INTRWAIT); return (error); } static int pcf8591_select_channel(device_t dev, int channel) { struct pcf8591_softc *sc; int error; uint8_t unused; sc = device_get_softc(dev); if (channel >= sc->sc_ch_count) return (EINVAL); sc->sc_cfg &= ~CTRL_CH_SELECT_MASK; sc->sc_cfg += channel; error = pcf8591_set_config(dev); if (error != 0) return (error); /* * The next read is still for the old channel, * so do it and discard. */ error = pcf8591_get_reading(dev, &unused); return (error); } static int pcf8591_channel_sysctl(SYSCTL_HANDLER_ARGS) { device_t dev; int error, channel, val; uint8_t reading; dev = arg1; channel = arg2; if (req->oldptr != NULL) { error = pcf8591_select_channel(dev, channel); if (error != 0) return (EIO); error = pcf8591_get_reading(dev, &reading); if (error != 0) return (EIO); val = reading; } error = sysctl_handle_int(oidp, &val, 0, req); return (error); } static void pcf8591_start(void *arg) { device_t dev; struct pcf8591_softc *sc; struct sysctl_ctx_list *ctx; struct sysctl_oid *tree_node; struct sysctl_oid_list *tree; struct sysctl_oid *inputs_node; struct sysctl_oid_list *inputs; sc = arg; dev = sc->sc_dev; /* * Set initial -- and, for the time being, fixed -- configuration. * Channel auto-incrementi is disabled, although it could be more * performant and precise for bulk channel queries. * The inputs are configured as four single channels. * The output is disabled. */ sc->sc_cfg = 0; sc->sc_output = 0; sc->sc_ch_count = 4; (void)pcf8591_set_config(dev); ctx = device_get_sysctl_ctx(dev); tree_node = device_get_sysctl_tree(dev); tree = SYSCTL_CHILDREN(tree_node); inputs_node = SYSCTL_ADD_NODE(ctx, tree, OID_AUTO, "inputs", CTLTYPE_NODE, NULL, "Input channels"); inputs = SYSCTL_CHILDREN(inputs_node); for (int i = 0; i < sc->sc_ch_count; i++) { char buf[4]; snprintf(buf, sizeof(buf), "%d", i); SYSCTL_ADD_PROC(ctx, inputs, OID_AUTO, buf, CTLTYPE_INT | CTLFLAG_RD, dev, i, pcf8591_channel_sysctl, "I", "Input level from 0 to 255 " "(relative to Vref)"); } } static int pcf8591_probe(device_t dev) { #ifdef FDT if (!ofw_bus_status_okay(dev)) return (ENXIO); #endif device_set_desc(dev, "PCF8591 8-bit ADC / DAC"); #ifdef FDT if (ofw_bus_search_compatible(dev, compat_data)->ocd_data) return (BUS_PROBE_GENERIC); #endif return (BUS_PROBE_NOWILDCARD); } static int pcf8591_attach(device_t dev) { struct pcf8591_softc *sc; sc = device_get_softc(dev); sc->sc_dev = dev; sc->sc_addr = iicbus_get_addr(dev); /* * We have to wait until interrupts are enabled. Usually I2C read * and write only works when the interrupts are available. */ config_intrhook_oneshot(pcf8591_start, sc); return (0); } static int pcf8591_detach(device_t dev) { return (0); } static device_method_t pcf8591_methods[] = { /* Device interface */ DEVMETHOD(device_probe, pcf8591_probe), DEVMETHOD(device_attach, pcf8591_attach), DEVMETHOD(device_detach, pcf8591_detach), DEVMETHOD_END }; static driver_t pcf8591_driver = { "pcf8591", pcf8591_methods, sizeof(struct pcf8591_softc) }; DRIVER_MODULE(pcf8591, iicbus, pcf8591_driver, 0, 0); MODULE_DEPEND(pcf8591, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER); MODULE_VERSION(pcf8591, 1); #ifdef FDT IICBUS_FDT_PNP_INFO(compat_data); #endif