mv_ts.c revision 239371 
1/*-
2 * Copyright (c) 2012 Hiroki Sato <hrs@FreeBSD.org>
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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * Driver for on-die thermal sensor in 88F6282 and 88F6283.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: head/sys/arm/mv/mv_ts.c 239371 2012-08-18 12:37:07Z hrs $");
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/kernel.h>
35#include <sys/module.h>
36#include <sys/bus.h>
37#include <sys/sysctl.h>
38#include <machine/fdt.h>
39
40#include <dev/fdt/fdt_common.h>
41#include <dev/ofw/ofw_bus.h>
42#include <dev/ofw/ofw_bus_subr.h>
43
44#include <arm/mv/mvreg.h>
45#include <arm/mv/mvvar.h>
46
47static struct resource_spec mvts_res[] = {
48	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
49	{ -1, 0 }
50};
51
52struct mvts_softc {
53	device_t		sc_dev;
54	struct resource		*sc_res[sizeof(mvts_res)];
55};
56
57static int
58ts_probe(device_t dev)
59{
60	uint32_t d, r;
61
62	if (!ofw_bus_is_compatible(dev, "mrvl,ts"))
63		return (ENXIO);
64	soc_id(&d, &r);
65	switch (d) {
66	case MV_DEV_88F6282:
67		break;
68	default:
69		device_printf(dev, "unsupported SoC (ID: 0x%08X)!\n", d);
70		return (ENXIO);
71	}
72	device_set_desc(dev, "Marvell Thermal Sensor");
73
74	return (0);
75}
76
77#define	MV_TEMP_VALID_BIT	(1 << 9)
78#define	MV_TEMP_SENS_OFFS	10
79#define	MV_TEMP_SENS_MASK	0x1ff
80#define	MV_TEMP_SENS_READ_MAX	16
81#define	TZ_ZEROC		2732
82#define	MV_TEMP_CONVERT(x)	((((322 - x) * 100000) / 13625) + TZ_ZEROC)
83
84/*
85 * MSB                                 LSB
86 * 0000 0000 0000 0000 0000 0000 0000 0000
87 *                             ^- valid bit
88 *                  |---------|
89 *                         ^--- temperature (9 bits)
90 */
91
92static int
93ts_sysctl_handler(SYSCTL_HANDLER_ARGS)
94{
95	struct mvts_softc *sc;
96	device_t dev;
97	uint32_t ret, ret0;
98	u_int val;
99	int i;
100
101	dev = (device_t)arg1;
102	sc = device_get_softc(dev);
103	val = TZ_ZEROC;
104
105	ret = bus_read_4(sc->sc_res[0], 0);
106	if ((ret & MV_TEMP_VALID_BIT) == 0) {
107		device_printf(dev, "temperature sensor is broken.\n");
108		goto ts_sysctl_handle_int;
109	}
110	ret0 = 0;
111	for (i = 0; i < MV_TEMP_SENS_READ_MAX; i++) {
112		ret = bus_read_4(sc->sc_res[0], 0);
113		ret = (ret >> MV_TEMP_SENS_OFFS) & MV_TEMP_SENS_MASK;
114
115		/*
116		 * Successive reads should returns the same value except
117		 * for the LSB when the sensor is normal.
118		 */
119		if (((ret0 ^ ret) & 0x1fe) == 0)
120			break;
121		else
122			ret0 = ret;
123	}
124	if (i == MV_TEMP_SENS_READ_MAX) {
125		device_printf(dev, "temperature sensor is unstable.\n");
126		goto ts_sysctl_handle_int;
127	}
128	val = (u_int)MV_TEMP_CONVERT(ret);
129
130ts_sysctl_handle_int:
131	return (sysctl_handle_int(oidp, &val, 0, req));
132}
133
134static int
135ts_attach(device_t dev)
136{
137	struct mvts_softc *sc;
138	struct sysctl_ctx_list *ctx;
139	int error;
140
141	sc = device_get_softc(dev);
142	sc->sc_dev = dev;
143	error = bus_alloc_resources(dev, mvts_res, sc->sc_res);
144	if (error) {
145		device_printf(dev, "could not allocate resources\n");
146		return (ENXIO);
147	}
148	ctx = device_get_sysctl_ctx(dev);
149	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
150	    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD, dev,
151	    0, ts_sysctl_handler, "IK", "Current Temperature");
152
153	return (0);
154}
155
156static int
157ts_detach(device_t dev)
158{
159
160	return (0);
161}
162
163static device_method_t ts_methods[] = {
164	DEVMETHOD(device_probe,		ts_probe),
165	DEVMETHOD(device_attach,	ts_attach),
166	DEVMETHOD(device_detach,	ts_detach),
167	{0, 0},
168};
169
170static driver_t ts_driver = {
171	"mvts",
172	ts_methods,
173	sizeof(struct mvts_softc),
174};
175
176static devclass_t ts_devclass;
177DRIVER_MODULE(mvts, simplebus, ts_driver, ts_devclass, 0, 0);
178MODULE_VERSION(mvts, 1);
179