ae1f3df434
only gpiobus configured via FDT is supported. Bus enumeration is supported. Devices are created for each device found. 1-Wire temperature controllers are supported, but other drivers could be written. Temperatures are polled and reported via a sysctl. Errors are reported via sysctl counters. Mis-wired bus detection is included for more trouble shooting. See ow(4), owc(4) and ow_temp(4) for details of what's supported and known issues. This has been tested on Raspberry Pi-B, Pi2 and Beagle Bone Black with up to 7 devices. Differential Revision: https://reviews.freebsd.org/D2956 Relnotes: yes MFC after: 2 weeks Reviewed by: loos@ (with many insightful comments)
286 lines
7.7 KiB
C
286 lines
7.7 KiB
C
/*-
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* Copyright (c) 2015 M. Warner Losh <imp@freebsd.org>
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* 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 unmodified, this list of conditions, and the following
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* 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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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/bus.h>
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#include <sys/errno.h>
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#include <sys/libkern.h>
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#include <sys/kthread.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/sysctl.h>
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#include <dev/ow/ow.h>
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#include <dev/ow/own.h>
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#define OWT_DS1820 0x10 /* Also 18S20 */
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#define OWT_DS1822 0x22 /* Very close to 18B20 */
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#define OWT_DS18B20 0x28 /* Also MAX31820 */
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#define OWT_DS1825 0x3B /* Just like 18B20 with address bits */
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#define CONVERT_T 0x44
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#define COPY_SCRATCHPAD 0x48
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#define WRITE_SCRATCHPAD 0x4e
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#define READ_POWER_SUPPLY 0xb4
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#define RECALL_EE 0xb8
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#define READ_SCRATCHPAD 0xbe
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#define OW_TEMP_DONE 0x01
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#define OW_TEMP_RUNNING 0x02
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struct ow_temp_softc
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{
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device_t dev;
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int type;
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int temp;
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int flags;
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int bad_crc;
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int bad_reads;
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int reading_interval;
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int parasite;
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struct mtx temp_lock;
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struct proc *event_thread;
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};
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static int
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ow_temp_probe(device_t dev)
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{
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switch (ow_get_family(dev)) {
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case OWT_DS1820:
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device_set_desc(dev, "One Wire Temperature");
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return BUS_PROBE_DEFAULT;
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case OWT_DS1822:
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case OWT_DS1825:
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case OWT_DS18B20:
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device_set_desc(dev, "Advanced One Wire Temperature");
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return BUS_PROBE_DEFAULT;
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default:
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return ENXIO;
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}
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}
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static int
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ow_temp_read_scratchpad(device_t dev, uint8_t *scratch, int len)
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{
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struct ow_cmd cmd;
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own_self_command(dev, &cmd, READ_SCRATCHPAD);
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cmd.xpt_read_len = len;
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own_command_wait(dev, &cmd);
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memcpy(scratch, cmd.xpt_read, len);
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return 0;
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}
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static int
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ow_temp_convert_t(device_t dev)
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{
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struct ow_cmd cmd;
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own_self_command(dev, &cmd, CONVERT_T);
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own_command_wait(dev, &cmd);
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return 0;
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}
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static int
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ow_temp_read_power_supply(device_t dev, int *parasite)
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{
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struct ow_cmd cmd;
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own_self_command(dev, &cmd, READ_POWER_SUPPLY);
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cmd.flags |= OW_FLAG_READ_BIT;
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cmd.xpt_read_len = 1;
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own_command_wait(dev, &cmd);
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*parasite = !cmd.xpt_read[0]; /* parasites pull bus low */
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return 0;
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}
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static void
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ow_temp_event_thread(void *arg)
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{
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struct ow_temp_softc *sc;
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uint8_t scratch[8 + 1];
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uint8_t crc;
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int retries, rv;
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sc = arg;
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pause("owtstart", device_get_unit(sc->dev) * hz / 100); // 10ms stagger
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mtx_lock(&sc->temp_lock);
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sc->flags |= OW_TEMP_RUNNING;
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ow_temp_read_power_supply(sc->dev, &sc->parasite);
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if (sc->parasite)
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device_printf(sc->dev, "Running in parasitic mode unsupported\n");
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while ((sc->flags & OW_TEMP_DONE) == 0) {
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mtx_unlock(&sc->temp_lock);
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ow_temp_convert_t(sc->dev);
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mtx_lock(&sc->temp_lock);
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msleep(sc, &sc->temp_lock, 0, "owtcvt", hz);
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if (sc->flags & OW_TEMP_DONE)
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break;
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for (retries = 5; retries > 0; retries--) {
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mtx_unlock(&sc->temp_lock);
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rv = ow_temp_read_scratchpad(sc->dev, scratch, sizeof(scratch));
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mtx_lock(&sc->temp_lock);
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if (rv == 0) {
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crc = own_crc(sc->dev, scratch, sizeof(scratch) - 1);
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if (crc == scratch[8]) {
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if (sc->type == OWT_DS1820) {
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if (scratch[7]) {
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/*
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* Formula from DS18S20 datasheet, page 6
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* DS18S20 datahseet says count_per_c is 16, DS1820 does not
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*/
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sc->temp = (int16_t)((scratch[0] & 0xfe) |
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(scratch[1] << 8)) << 3;
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sc->temp += 16 - scratch[6] - 4; /* count_per_c == 16 */
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} else
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sc->temp = (int16_t)(scratch[0] | (scratch[1] << 8)) << 3;
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} else
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sc->temp = (int16_t)(scratch[0] | (scratch[1] << 8));
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sc->temp = sc->temp * 1000 / 16 + 273150;
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break;
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}
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sc->bad_crc++;
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} else
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sc->bad_reads++;
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}
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msleep(sc, &sc->temp_lock, 0, "owtcvt", sc->reading_interval);
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}
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sc->flags &= ~OW_TEMP_RUNNING;
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mtx_unlock(&sc->temp_lock);
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kproc_exit(0);
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}
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static int
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ow_temp_attach(device_t dev)
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{
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struct ow_temp_softc *sc;
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sc = device_get_softc(dev);
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sc->dev = dev;
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sc->type = ow_get_family(dev);
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SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
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SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
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OID_AUTO, "temperature", CTLFLAG_RD | CTLTYPE_INT,
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&sc->temp, 0, sysctl_handle_int,
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"IK3", "Current Temperature");
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SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
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SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
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OID_AUTO, "badcrc", CTLFLAG_RD,
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&sc->bad_crc, 0,
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"Number of Bad CRC on reading scratchpad");
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SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
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SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
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OID_AUTO, "badread", CTLFLAG_RD,
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&sc->bad_reads, 0,
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"Number of errors on reading scratchpad");
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SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
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SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
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OID_AUTO, "reading_interval", CTLFLAG_RW,
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&sc->reading_interval, 0,
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"ticks between reads");
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SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
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SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
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OID_AUTO, "parasite", CTLFLAG_RW,
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&sc->parasite, 0,
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"In Parasite mode");
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/*
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* Just do this for unit 0 to avoid locking
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* the ow bus until that code can be put
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* into place.
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*/
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sc->temp = -1;
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sc->reading_interval = 10 * hz;
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mtx_init(&sc->temp_lock, "lock for doing temperature", NULL, MTX_DEF);
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/* Start the thread */
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if (kproc_create(ow_temp_event_thread, sc, &sc->event_thread, 0, 0,
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"%s event thread", device_get_nameunit(dev))) {
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device_printf(dev, "unable to create event thread.\n");
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panic("cbb_create_event_thread");
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}
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return 0;
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}
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static int
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ow_temp_detach(device_t dev)
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{
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struct ow_temp_softc *sc;
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sc = device_get_softc(dev);
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/*
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* Wait for the thread to die. kproc_exit will do a wakeup
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* on the event thread's struct thread * so that we know it is
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* safe to proceed. IF the thread is running, set the please
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* die flag and wait for it to comply. Since the wakeup on
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* the event thread happens only in kproc_exit, we don't
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* need to loop here.
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*/
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mtx_lock(&sc->temp_lock);
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sc->flags |= OW_TEMP_DONE;
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while (sc->flags & OW_TEMP_RUNNING) {
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wakeup(sc);
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msleep(sc->event_thread, &sc->temp_lock, PWAIT, "owtun", 0);
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}
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mtx_destroy(&sc->temp_lock);
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return 0;
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}
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devclass_t ow_temp_devclass;
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static device_method_t ow_temp_methods[] = {
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/* Device interface */
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DEVMETHOD(device_probe, ow_temp_probe),
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DEVMETHOD(device_attach, ow_temp_attach),
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DEVMETHOD(device_detach, ow_temp_detach),
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{ 0, 0 }
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};
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static driver_t ow_temp_driver = {
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"ow_temp",
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ow_temp_methods,
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sizeof(struct ow_temp_softc),
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};
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DRIVER_MODULE(ow_temp, ow, ow_temp_driver, ow_temp_devclass, 0, 0);
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MODULE_DEPEND(ow_temp, ow, 1, 1, 1);
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