max6657.c revision 216390 
1/*-
2 * Copyright (c) 2003-2009 RMI Corporation
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of RMI Corporation, nor the names of its contributors,
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
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 * RMI_BSD */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/sys/mips/rmi/dev/iic/max6657.c 216390 2010-12-12 06:00:26Z jchandra $");
33/*
34 * temperature sensor chip sitting on the I2C bus.
35 */
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/kernel.h>
39#include <sys/lock.h>
40#include <sys/module.h>
41#include <sys/mutex.h>
42#include <sys/bus.h>
43#include <sys/resource.h>
44#include <sys/rman.h>
45#include <sys/sysctl.h>
46
47#include <machine/bus.h>
48#include <machine/cpu.h>
49#include <machine/cpufunc.h>
50#include <machine/frame.h>
51#include <machine/resource.h>
52
53#include <dev/iicbus/iiconf.h>
54#include <dev/iicbus/iicbus.h>
55
56#include <mips/rmi/board.h>
57#include <mips/rmi/rmi_boot_info.h>
58#include "iicbus_if.h"
59
60#define	MAX6657_EXT_TEMP	1
61
62struct max6657_softc {
63	uint32_t	sc_addr;
64	device_t	sc_dev;
65	struct mtx	sc_mtx;
66	int		sc_curtemp;
67	int		sc_lastupdate;	/* in ticks */
68};
69
70static void max6657_update(struct max6657_softc *);
71static int max6657_read(device_t dev, uint32_t addr, int reg) ;
72
73static int
74max6657_probe(device_t dev)
75{
76	device_set_desc(dev, "MAX6657MSA Temperature Sensor");
77	return (0);
78}
79
80static int
81max6657_sysctl_temp(SYSCTL_HANDLER_ARGS)
82{
83	struct max6657_softc *sc = arg1;
84	int temp;
85
86	max6657_update(sc);
87	temp = sc->sc_curtemp ;
88	return sysctl_handle_int(oidp, &temp, 0, req);
89}
90
91static int
92max6657_attach(device_t dev)
93{
94	struct max6657_softc *sc = device_get_softc(dev);
95	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev);
96	struct sysctl_oid *tree = device_get_sysctl_tree(dev);
97
98	if(sc==NULL) {
99		printf("max6657_attach device_get_softc failed\n");
100		return (0);
101	}
102	sc->sc_dev = dev;
103	sc->sc_addr = iicbus_get_addr(dev);
104	mtx_init(&sc->sc_mtx, "max6657", "max6657", MTX_DEF);
105
106	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
107		"temp", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
108		max6657_sysctl_temp, "I", "operating temperature");
109
110	device_printf(dev, "Chip temperature {%d} Degree Celsius\n",
111		max6657_read(sc->sc_dev, sc->sc_addr, MAX6657_EXT_TEMP));
112
113	return (0);
114}
115
116static int
117max6657_read(device_t dev, uint32_t slave_addr, int reg)
118{
119	uint8_t addr = reg;
120	uint8_t data[1];
121	struct iic_msg msgs[2] = {
122	     { slave_addr, IIC_M_WR, 1, &addr },
123	     { slave_addr, IIC_M_RD, 1, data },
124	};
125
126	return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0];
127}
128
129
130static void
131max6657_update(struct max6657_softc *sc)
132{
133	int v;
134
135	mtx_lock(&sc->sc_mtx);
136	/* NB: no point in updating any faster than the chip */
137	if (ticks - sc->sc_lastupdate > hz) {
138		v = max6657_read(sc->sc_dev, sc->sc_addr, MAX6657_EXT_TEMP);
139		if (v >= 0)
140			sc->sc_curtemp = v;
141		sc->sc_lastupdate = ticks;
142	}
143	mtx_unlock(&sc->sc_mtx);
144}
145
146static device_method_t max6657_methods[] = {
147	DEVMETHOD(device_probe,		max6657_probe),
148	DEVMETHOD(device_attach,	max6657_attach),
149
150	{0, 0},
151};
152
153static driver_t max6657_driver = {
154	"max6657",
155	max6657_methods,
156	sizeof(struct max6657_softc),
157};
158static devclass_t max6657_devclass;
159
160DRIVER_MODULE(max6657, iicbus, max6657_driver, max6657_devclass, 0, 0);
161MODULE_VERSION(max6657, 1);
162MODULE_DEPEND(max6657, iicbus, 1, 1, 1);
163