73440c336d
an eeprom device with iicbus_request/release_bus(), which achieves the same effect and also keeps other i2c slave drivers from clashing on the bus.
279 lines
7.2 KiB
C
279 lines
7.2 KiB
C
/*-
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* Copyright (c) 2006 Warner Losh. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* Generic IIC eeprom support, modeled after the AT24C family of products.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/conf.h>
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#include <sys/kernel.h>
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#include <sys/module.h>
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#include <sys/resource.h>
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#include <sys/sx.h>
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#include <sys/uio.h>
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#include <machine/bus.h>
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#include <dev/iicbus/iiconf.h>
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#include <dev/iicbus/iicbus.h>
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#include "iicbus_if.h"
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#define IIC_M_WR 0 /* write operation */
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#define MAX_RD_SZ 256 /* Largest read size we support */
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#define MAX_WR_SZ 256 /* Largest write size we support */
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struct icee_softc {
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device_t sc_dev; /* Myself */
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device_t sc_busdev; /* Parent bus */
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struct cdev *cdev; /* user interface */
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int addr;
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int size; /* How big am I? */
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int type; /* What type 8 or 16 bit? */
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int rd_sz; /* What's the read page size */
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int wr_sz; /* What's the write page size */
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};
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#define CDEV2SOFTC(dev) ((dev)->si_drv1)
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/* cdev routines */
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static d_open_t icee_open;
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static d_close_t icee_close;
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static d_read_t icee_read;
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static d_write_t icee_write;
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static struct cdevsw icee_cdevsw =
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{
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.d_version = D_VERSION,
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.d_flags = D_TRACKCLOSE,
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.d_open = icee_open,
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.d_close = icee_close,
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.d_read = icee_read,
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.d_write = icee_write
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};
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static int
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icee_probe(device_t dev)
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{
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device_set_desc(dev, "I2C EEPROM");
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return (BUS_PROBE_NOWILDCARD);
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}
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static int
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icee_attach(device_t dev)
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{
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struct icee_softc *sc = device_get_softc(dev);
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const char *dname;
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int dunit, err;
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sc->sc_dev = dev;
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sc->sc_busdev = device_get_parent(sc->sc_dev);
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sc->addr = iicbus_get_addr(dev);
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err = 0;
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dname = device_get_name(dev);
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dunit = device_get_unit(dev);
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resource_int_value(dname, dunit, "size", &sc->size);
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resource_int_value(dname, dunit, "type", &sc->type);
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resource_int_value(dname, dunit, "rd_sz", &sc->rd_sz);
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if (sc->rd_sz > MAX_RD_SZ)
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sc->rd_sz = MAX_RD_SZ;
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resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz);
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if (bootverbose)
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device_printf(dev, "size: %d bytes bus_width: %d-bits\n",
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sc->size, sc->type);
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sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
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GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
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if (sc->cdev == NULL) {
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err = ENOMEM;
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goto out;
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}
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sc->cdev->si_drv1 = sc;
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out:
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return (err);
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}
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static int
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icee_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
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{
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return (0);
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}
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static int
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icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
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{
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return (0);
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}
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static int
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icee_read(struct cdev *dev, struct uio *uio, int ioflag)
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{
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struct icee_softc *sc;
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uint8_t addr[2];
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uint8_t data[MAX_RD_SZ];
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int error, i, len, slave;
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struct iic_msg msgs[2] = {
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{ 0, IIC_M_WR, 1, addr },
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{ 0, IIC_M_RD, 0, data },
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};
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sc = CDEV2SOFTC(dev);
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if (uio->uio_offset == sc->size)
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return (0);
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if (uio->uio_offset > sc->size)
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return (EIO);
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if (sc->type != 8 && sc->type != 16)
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return (EINVAL);
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error = iicbus_request_bus(sc->sc_busdev, sc->sc_dev, IIC_INTRWAIT);
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if (error!= 0)
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return (iic2errno(error));
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slave = error = 0;
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while (uio->uio_resid > 0) {
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if (uio->uio_offset >= sc->size)
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break;
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len = MIN(sc->rd_sz - (uio->uio_offset & (sc->rd_sz - 1)),
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uio->uio_resid);
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switch (sc->type) {
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case 8:
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slave = (uio->uio_offset >> 7) | sc->addr;
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msgs[0].len = 1;
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msgs[1].len = len;
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addr[0] = uio->uio_offset & 0xff;
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break;
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case 16:
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slave = sc->addr | (uio->uio_offset >> 15);
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msgs[0].len = 2;
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msgs[1].len = len;
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addr[0] = (uio->uio_offset >> 8) & 0xff;
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addr[1] = uio->uio_offset & 0xff;
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break;
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}
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for (i = 0; i < 2; i++)
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msgs[i].slave = slave;
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error = iicbus_transfer(sc->sc_dev, msgs, 2);
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if (error) {
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error = iic2errno(error);
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break;
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}
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error = uiomove(data, len, uio);
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if (error)
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break;
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}
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iicbus_release_bus(sc->sc_busdev, sc->sc_dev);
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return (error);
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}
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/*
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* Write to the part. We use three transfers here since we're actually
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* doing a write followed by a read to make sure that the write finished.
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* It is easier to encode the dummy read here than to break things up
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* into smaller chunks...
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*/
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static int
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icee_write(struct cdev *dev, struct uio *uio, int ioflag)
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{
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struct icee_softc *sc;
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int error, len, slave, waitlimit;
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uint8_t data[MAX_WR_SZ + 2];
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struct iic_msg wr[1] = {
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{ 0, IIC_M_WR, 0, data },
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};
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struct iic_msg rd[1] = {
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{ 0, IIC_M_RD, 1, data },
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};
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sc = CDEV2SOFTC(dev);
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if (uio->uio_offset >= sc->size)
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return (EIO);
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if (sc->type != 8 && sc->type != 16)
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return (EINVAL);
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error = iicbus_request_bus(sc->sc_busdev, sc->sc_dev, IIC_INTRWAIT);
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if (error!= 0)
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return (iic2errno(error));
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slave = error = 0;
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while (uio->uio_resid > 0) {
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if (uio->uio_offset >= sc->size)
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break;
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len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
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uio->uio_resid);
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switch (sc->type) {
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case 8:
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slave = (uio->uio_offset >> 7) | sc->addr;
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wr[0].len = 1 + len;
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data[0] = uio->uio_offset & 0xff;
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break;
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case 16:
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slave = sc->addr | (uio->uio_offset >> 15);
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wr[0].len = 2 + len;
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data[0] = (uio->uio_offset >> 8) & 0xff;
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data[1] = uio->uio_offset & 0xff;
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break;
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}
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wr[0].slave = slave;
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error = uiomove(data + sc->type / 8, len, uio);
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if (error)
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break;
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error = iicbus_transfer(sc->sc_dev, wr, 1);
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if (error) {
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error = iic2errno(error);
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break;
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}
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/* Read after write to wait for write-done. */
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waitlimit = 10000;
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rd[0].slave = slave;
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do {
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error = iicbus_transfer(sc->sc_dev, rd, 1);
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} while (waitlimit-- > 0 && error != 0);
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if (error) {
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error = iic2errno(error);
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break;
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}
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}
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iicbus_release_bus(sc->sc_busdev, sc->sc_dev);
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return error;
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}
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static device_method_t icee_methods[] = {
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DEVMETHOD(device_probe, icee_probe),
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DEVMETHOD(device_attach, icee_attach),
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DEVMETHOD_END
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};
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static driver_t icee_driver = {
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"icee",
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icee_methods,
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sizeof(struct icee_softc),
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};
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static devclass_t icee_devclass;
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DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0);
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MODULE_VERSION(icee, 1);
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MODULE_DEPEND(icee, iicbus, 1, 1, 1);
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