NetBSD-5.0.2/sys/dev/i2c/lm75.c
/* $NetBSD: lm75.c,v 1.19 2008/04/06 20:25:59 cegger Exp $ */
/*
* Copyright (c) 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Jason R. Thorpe for Wasabi Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: lm75.c,v 1.19 2008/04/06 20:25:59 cegger Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <dev/sysmon/sysmonvar.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/lm75reg.h>
struct lmtemp_softc {
i2c_tag_t sc_tag;
int sc_address;
struct sysmon_envsys *sc_sme;
envsys_data_t sc_sensor;
uint32_t (*sc_lmtemp_decode)(const uint8_t *);
};
static int lmtemp_match(device_t, cfdata_t, void *);
static void lmtemp_attach(device_t, device_t, void *);
CFATTACH_DECL_NEW(lmtemp, sizeof(struct lmtemp_softc),
lmtemp_match, lmtemp_attach, NULL, NULL);
static void lmtemp_refresh(struct sysmon_envsys *, envsys_data_t *);
static int lmtemp_config_write(struct lmtemp_softc *, uint8_t);
static uint32_t lmtemp_decode_lm75(const uint8_t *);
static uint32_t lmtemp_decode_ds75(const uint8_t *);
static uint32_t lmtemp_decode_lm77(const uint8_t *);
enum {
lmtemp_lm75 = 0,
lmtemp_ds75,
lmtemp_lm77,
};
static const struct {
int lmtemp_type;
const char *lmtemp_name;
int lmtemp_addrmask;
int lmtemp_addr;
uint32_t (*lmtemp_decode)(const uint8_t *);
} lmtemptbl[] = {
{ lmtemp_lm75, "LM75",
LM75_ADDRMASK, LM75_ADDR, lmtemp_decode_lm75 },
{ lmtemp_ds75, "DS75",
LM75_ADDRMASK, LM75_ADDR, lmtemp_decode_ds75 },
{ lmtemp_lm77, "LM77",
LM77_ADDRMASK, LM77_ADDR, lmtemp_decode_lm77 },
{ -1, NULL,
0, 0, NULL }
};
static int
lmtemp_match(device_t parent, cfdata_t cf, void *aux)
{
struct i2c_attach_args *ia = aux;
int i;
for (i = 0; lmtemptbl[i].lmtemp_type != -1 ; i++)
if (lmtemptbl[i].lmtemp_type == cf->cf_flags)
break;
if (lmtemptbl[i].lmtemp_type == -1)
return 0;
if ((ia->ia_addr & lmtemptbl[i].lmtemp_addrmask) ==
lmtemptbl[i].lmtemp_addr)
return 1;
return 0;
}
static void
lmtemp_attach(device_t parent, device_t self, void *aux)
{
struct lmtemp_softc *sc = device_private(self);
struct i2c_attach_args *ia = aux;
int i;
for (i = 0; lmtemptbl[i].lmtemp_type != -1 ; i++)
if (lmtemptbl[i].lmtemp_type ==
device_cfdata(self)->cf_flags)
break;
sc->sc_tag = ia->ia_tag;
sc->sc_address = ia->ia_addr;
aprint_naive(": Temperature Sensor\n");
aprint_normal(": %s Temperature Sensor\n", lmtemptbl[i].lmtemp_name);
/* Set the configuration of the LM75 to defaults. */
iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
if (lmtemp_config_write(sc, 0) != 0) {
aprint_error_dev(self, "unable to write config register\n");
iic_release_bus(sc->sc_tag, I2C_F_POLL);
return;
}
iic_release_bus(sc->sc_tag, I2C_F_POLL);
sc->sc_sme = sysmon_envsys_create();
/* Initialize sensor data. */
sc->sc_sensor.units = ENVSYS_STEMP;
(void)strlcpy(sc->sc_sensor.desc, device_xname(self),
sizeof(sc->sc_sensor.desc));
if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
sysmon_envsys_destroy(sc->sc_sme);
return;
}
sc->sc_lmtemp_decode = lmtemptbl[i].lmtemp_decode;
/* Hook into system monitor. */
sc->sc_sme->sme_name = device_xname(self);
sc->sc_sme->sme_cookie = sc;
sc->sc_sme->sme_refresh = lmtemp_refresh;
if (sysmon_envsys_register(sc->sc_sme)) {
aprint_error_dev(self, "unable to register with sysmon\n");
sysmon_envsys_destroy(sc->sc_sme);
}
}
static int
lmtemp_config_write(struct lmtemp_softc *sc, uint8_t val)
{
uint8_t cmdbuf[2];
cmdbuf[0] = LM75_REG_CONFIG;
cmdbuf[1] = val;
return iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, I2C_F_POLL);
}
static int
lmtemp_temp_read(struct lmtemp_softc *sc, uint8_t which, uint32_t *valp)
{
int error;
uint8_t cmdbuf[1];
uint8_t buf[LM75_TEMP_LEN];
cmdbuf[0] = which;
error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1, buf, LM75_TEMP_LEN, 0);
if (error)
return error;
*valp = sc->sc_lmtemp_decode(buf);
return 0;
}
static void
lmtemp_refresh_sensor_data(struct lmtemp_softc *sc)
{
uint32_t val;
int error;
error = lmtemp_temp_read(sc, LM75_REG_TEMP, &val);
if (error) {
#if 0
aprint_error_dev(&sc->sc_dev, "unable to read temperature, error = %d\n",
error);
#endif
sc->sc_sensor.state = ENVSYS_SINVALID;
return;
}
sc->sc_sensor.value_cur = val;
sc->sc_sensor.state = ENVSYS_SVALID;
}
static void
lmtemp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
struct lmtemp_softc *sc = sme->sme_cookie;
iic_acquire_bus(sc->sc_tag, 0); /* also locks our instance */
lmtemp_refresh_sensor_data(sc);
iic_release_bus(sc->sc_tag, 0); /* also unlocks our instance */
}
static uint32_t
lmtemp_decode_lm75(const uint8_t *buf)
{
int neg, temp;
uint32_t val;
if (buf[0] & 1) {
/* Below 0C */
temp = ~buf[1] + 1;
neg = 1;
} else {
temp = buf[1];
neg = 0;
}
/* Temp is given in 1/2 deg. C, we convert to uK. */
val = ((neg ? -temp : temp) / 2) * 1000000 + 273150000;
if (temp & 1) {
if (neg)
val -= 500000;
else
val += 500000;
}
return val;
}
static uint32_t
lmtemp_decode_ds75(const uint8_t *buf)
{
int temp;
/*
* Sign-extend the MSB byte, and add in the fractions of a
* degree contained in the LSB (precision 1/16th DegC).
*/
temp = (int8_t)buf[0];
temp = (temp << 4) | ((buf[1] >> 4) & 0xf);
/*
* Conversion to uK is simple.
*/
return (temp * 62500 + 273150000);
}
static uint32_t
lmtemp_decode_lm77(const uint8_t *buf)
{
int temp;
uint32_t val;
/*
* Describe each bits of temperature registers on LM77.
* D15 - D12: Sign
* D11 - D3 : Bit8(MSB) - Bit0
*/
temp = (int8_t)buf[0];
temp = (temp << 5) | ((buf[1] >> 3) & 0x1f);
/* Temp is given in 1/2 deg. C, we convert to uK. */
val = temp * 500000 + 273150000;
return val;
}