pca954x.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10

    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause
    3  *
    4  * Copyright (c) 2019 Ian Lepore <ian@freebsd.org>
    5  * Copyright (c) 2020-2021 Andriy Gapon
    6  * Copyright (c) 2022 Bjoern A. Zeeb
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 #include <sys/cdefs.h>
   31 __FBSDID("$FreeBSD$");
   32 
   33 #include "opt_platform.h"
   34 
   35 #include <sys/param.h>
   36 #include <sys/bus.h>
   37 #include <sys/kernel.h>
   38 #include <sys/module.h>
   39 #include <sys/systm.h>
   40 
   41 #ifdef FDT
   42 #include <dev/ofw/ofw_bus.h>
   43 #include <dev/ofw/ofw_bus_subr.h>
   44 #include <dev/ofw/openfirm.h>
   45 #endif
   46 
   47 #include <dev/iicbus/iicbus.h>
   48 #include <dev/iicbus/iiconf.h>
   49 #include "iicbus_if.h"
   50 #include "iicmux_if.h"
   51 #include <dev/iicbus/mux/iicmux.h>
   52 
   53 enum pca954x_type {
   54         PCA954X_MUX,
   55         PCA954X_SW,
   56 };
   57 
   58 struct pca954x_descr {
   59         const char              *partname;
   60         const char              *description;
   61         enum pca954x_type       type;
   62         uint8_t                 numchannels;
   63         uint8_t                 enable;
   64 };
   65 
   66 static struct pca954x_descr pca9540_descr = {
   67         .partname = "pca9540",
   68         .description = "PCA9540B I2C Mux",
   69         .type = PCA954X_MUX,
   70         .numchannels = 2,
   71         .enable = 0x04,
   72 };
   73 
   74 static struct pca954x_descr pca9547_descr = {
   75         .partname = "pca9547",
   76         .description = "PCA9547 I2C Mux",
   77         .type = PCA954X_MUX,
   78         .numchannels = 8,
   79         .enable = 0x08,
   80 };
   81 
   82 static struct pca954x_descr pca9548_descr = {
   83         .partname = "pca9548",
   84         .description = "PCA9548A I2C Switch",
   85         .type = PCA954X_SW,
   86         .numchannels = 8,
   87 };
   88 
   89 #ifdef FDT
   90 static struct ofw_compat_data compat_data[] = {
   91         { "nxp,pca9540", (uintptr_t)&pca9540_descr },
   92         { "nxp,pca9547", (uintptr_t)&pca9547_descr },
   93         { "nxp,pca9548", (uintptr_t)&pca9548_descr },
   94         { NULL, 0 },
   95 };
   96 #else
   97 static struct pca954x_descr *part_descrs[] = {
   98         &pca9540_descr,
   99         &pca9547_descr,
  100         &pca9548_descr,
  101 };
  102 #endif
  103 
  104 struct pca954x_softc {
  105         struct iicmux_softc mux;
  106         const struct pca954x_descr *descr;
  107         uint8_t addr;
  108         bool idle_disconnect;
  109 };
  110 
  111 static int
  112 pca954x_bus_select(device_t dev, int busidx, struct iic_reqbus_data *rd)
  113 {
  114         struct pca954x_softc *sc;
  115         struct iic_msg msg;
  116         int error;
  117         uint8_t busbits;
  118 
  119         sc = device_get_softc(dev);
  120 
  121         /*
  122          * The iicmux caller ensures busidx is between 0 and the number of buses
  123          * we passed to iicmux_init_softc(), no need for validation here.  If
  124          * the fdt data has the idle_disconnect property we idle the bus by
  125          * selecting no downstream buses, otherwise we just leave the current
  126          * bus active.
  127          */
  128         if (busidx == IICMUX_SELECT_IDLE) {
  129                 if (sc->idle_disconnect)
  130                         busbits = 0;
  131                 else
  132                         return (0);
  133         } else if (sc->descr->type == PCA954X_MUX) {
  134                 uint8_t en;
  135 
  136                 en = sc->descr->enable;
  137                 KASSERT(en > 0 && powerof2(en), ("%s: %s enable %#x "
  138                     "invalid\n", __func__, sc->descr->partname, en));
  139                 busbits = en | (busidx & (en - 1));
  140         } else if (sc->descr->type == PCA954X_SW) {
  141                 busbits = 1u << busidx;
  142         } else {
  143                 panic("%s: %s: unsupported type %d\n",
  144                     __func__, sc->descr->partname, sc->descr->type);
  145         }
  146 
  147         msg.slave = sc->addr;
  148         msg.flags = IIC_M_WR;
  149         msg.len = 1;
  150         msg.buf = &busbits;
  151         error = iicbus_transfer(dev, &msg, 1);
  152         return (error);
  153 }
  154 
  155 static const struct pca954x_descr *
  156 pca954x_find_chip(device_t dev)
  157 {
  158 #ifdef FDT
  159         const struct ofw_compat_data *compat;
  160 
  161         if (!ofw_bus_status_okay(dev))
  162                 return (NULL);
  163 
  164         compat = ofw_bus_search_compatible(dev, compat_data);
  165         if (compat == NULL)
  166                 return (NULL);
  167         return ((const struct pca954x_descr *)compat->ocd_data);
  168 #else
  169         const char *type;
  170         int i;
  171 
  172         if (resource_string_value(device_get_name(dev), device_get_unit(dev),
  173             "chip_type", &type) == 0) {
  174                 for (i = 0; i < nitems(part_descrs) - 1; ++i) {
  175                         if (strcasecmp(type, part_descrs[i]->partname) == 0)
  176                                 return (part_descrs[i]);
  177                 }
  178         }
  179         return (NULL);
  180 #endif
  181 }
  182 
  183 static int
  184 pca954x_probe(device_t dev)
  185 {
  186         const struct pca954x_descr *descr;
  187 
  188         descr = pca954x_find_chip(dev);
  189         if (descr == NULL)
  190                 return (ENXIO);
  191 
  192         device_set_desc(dev, descr->description);
  193         return (BUS_PROBE_DEFAULT);
  194 }
  195 
  196 static int
  197 pca954x_attach(device_t dev)
  198 {
  199         struct pca954x_softc *sc;
  200         const struct pca954x_descr *descr;
  201         int error;
  202 
  203         sc = device_get_softc(dev);
  204         sc->addr = iicbus_get_addr(dev);
  205         sc->idle_disconnect = device_has_property(dev, "i2c-mux-idle-disconnect");
  206 
  207         sc->descr = descr = pca954x_find_chip(dev);
  208         error = iicmux_attach(dev, device_get_parent(dev), descr->numchannels);
  209         if (error == 0)
  210                 bus_generic_attach(dev);
  211 
  212         return (error);
  213 }
  214 
  215 static int
  216 pca954x_detach(device_t dev)
  217 {
  218         int error;
  219 
  220         error = iicmux_detach(dev);
  221         return (error);
  222 }
  223 
  224 static device_method_t pca954x_methods[] = {
  225         /* device methods */
  226         DEVMETHOD(device_probe,                 pca954x_probe),
  227         DEVMETHOD(device_attach,                pca954x_attach),
  228         DEVMETHOD(device_detach,                pca954x_detach),
  229 
  230         /* iicmux methods */
  231         DEVMETHOD(iicmux_bus_select,            pca954x_bus_select),
  232 
  233         DEVMETHOD_END
  234 };
  235 
  236 DEFINE_CLASS_1(pca954x, pca954x_driver, pca954x_methods,
  237     sizeof(struct pca954x_softc), iicmux_driver);
  238 DRIVER_MODULE(pca954x, iicbus, pca954x_driver, 0, 0);
  239 
  240 #ifdef FDT
  241 DRIVER_MODULE(ofw_iicbus, pca954x, ofw_iicbus_driver, 0, 0);
  242 #else
  243 DRIVER_MODULE(iicbus, pca954x, iicbus_driver, 0, 0);
  244 #endif
  245 
  246 MODULE_DEPEND(pca954x, iicmux, 1, 1, 1);
  247 MODULE_DEPEND(pca954x, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
  248 MODULE_VERSION(pca954x, 1);
  249 
  250 #ifdef FDT
  251 IICBUS_FDT_PNP_INFO(compat_data);
  252 #endif

Cache object: c18ec09ddf267064c07e8085ef27eb62

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.

FreeBSD/Linux Kernel Cross Reference sys/dev/iicbus/mux/pca954x.c

FreeBSD/Linux Kernel Cross Reference
sys/dev/iicbus/mux/pca954x.c