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/* $OpenBSD: pcf8591_ofw.c,v 1.5 2007/10/22 20:53:10 cnst Exp $ */
/*
* Copyright (c) 2006 Damien Miller <djm@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/sensors.h>
#include <dev/ofw/openfirm.h>
#include <dev/i2c/i2cvar.h>
#define PCF8591_CHANNELS 4
struct pcfadc_channel {
u_int chan_num;
struct ksensor chan_sensor;
};
struct pcfadc_softc {
struct device sc_dev;
i2c_tag_t sc_tag;
i2c_addr_t sc_addr;
u_char sc_xlate[256];
u_int sc_nchan;
struct pcfadc_channel sc_channels[PCF8591_CHANNELS];
struct ksensordev sc_sensordev;
};
int pcfadc_match(struct device *, void *, void *);
void pcfadc_attach(struct device *, struct device *, void *);
void pcfadc_refresh(void *);
struct cfattach pcfadc_ca = {
sizeof(struct pcfadc_softc), pcfadc_match, pcfadc_attach
};
struct cfdriver pcfadc_cd = {
NULL, "pcfadc", DV_DULL
};
int
pcfadc_match(struct device *parent, void *match, void *aux)
{
struct i2c_attach_args *ia = aux;
if (strcmp(ia->ia_name, "i2cpcf,8591") != 0)
return (0);
return (1);
}
void
pcfadc_attach(struct device *parent, struct device *self, void *aux)
{
struct pcfadc_softc *sc = (struct pcfadc_softc *)self;
u_char chanuse[PCF8591_CHANNELS * 4], desc[PCF8591_CHANNELS * 32];
u_char *cp;
u_int8_t junk[PCF8591_CHANNELS + 1];
u_int32_t transinfo[PCF8591_CHANNELS * 4];
struct i2c_attach_args *ia = aux;
int dlen, clen, tlen, node = *(int *)ia->ia_cookie;
u_int i;
if ((dlen = OF_getprop(node, "channels-description", desc,
sizeof(desc))) < 0) {
printf(": couldn't find \"channels-description\" property\n");
return;
}
if (dlen > sizeof(desc) || desc[dlen - 1] != '\0') {
printf(": bad \"channels-description\" property\n");
return;
}
if ((clen = OF_getprop(node, "channels-in-use", chanuse,
sizeof(chanuse))) < 0) {
printf(": couldn't find \"channels-in-use\" property\n");
return;
}
if ((clen % 4) != 0) {
printf(": invalid \"channels-in-use\" length %d\n", clen);
return;
}
sc->sc_nchan = clen / 4;
if (sc->sc_nchan > PCF8591_CHANNELS) {
printf(": invalid number of channels (%d)\n", sc->sc_nchan);
return;
}
if ((tlen = OF_getprop(node, "tables", sc->sc_xlate,
sizeof(sc->sc_xlate))) < 0) {
printf(": couldn't find \"tables\" property\n");
return;
}
/* We only support complete, single width tables */
if (tlen != 256) {
printf(": invalid \"tables\" length %d\n", tlen);
return;
}
if ((tlen = OF_getprop(node, "translation", transinfo,
sizeof(transinfo))) < 0) {
printf(": couldn't find \"translation\" property\n");
return;
}
if (tlen != (sc->sc_nchan * 4 * 4)) {
printf(": invalid \"translation\" length %d\n", tlen);
return;
}
cp = desc;
for (i = 0; i < sc->sc_nchan; i++) {
struct pcfadc_channel *chp = &sc->sc_channels[i];
chp->chan_sensor.type = SENSOR_TEMP;
if (cp >= desc + dlen) {
printf(": invalid \"channels-description\"\n");
return;
}
strlcpy(chp->chan_sensor.desc, cp,
sizeof(chp->chan_sensor.desc));
cp += strlen(cp) + 1;
/*
* We only support input temperature channels, with
* valid channel numbers, and basic (unscaled) translation
*
* XXX TODO: support voltage (type 2) channels and type 4
* (scaled) translation tables
*/
if (chanuse[(i * 4)] > PCF8591_CHANNELS || /* channel # */
chanuse[(i * 4) + 1] != 0 || /* dir == input */
chanuse[(i * 4) + 2] != 1 || /* type == temp */
transinfo[(i * 4)] != 3 || /* xlate == table */
transinfo[(i * 4) + 2] != 0 || /* no xlate offset */
transinfo[(i * 4) + 3] != 0x100) { /* xlate tbl length */
printf(": unsupported sensor %d\n", i);
return;
}
chp->chan_num = chanuse[(i * 4)];
}
sc->sc_tag = ia->ia_tag;
sc->sc_addr = ia->ia_addr;
iic_acquire_bus(sc->sc_tag, 0);
/* Try a read now, so we can fail if it doesn't work */
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
NULL, 0, junk, sc->sc_nchan + 1, 0)) {
printf(": read failed\n");
iic_release_bus(sc->sc_tag, 0);
return;
}
iic_release_bus(sc->sc_tag, 0);
/* Initialize sensor data. */
strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
sizeof(sc->sc_sensordev.xname));
for (i = 0; i < sc->sc_nchan; i++)
sensor_attach(&sc->sc_sensordev,
&sc->sc_channels[i].chan_sensor);
if (sensor_task_register(sc, pcfadc_refresh, 5) == NULL) {
printf(": unable to register update task\n");
return;
}
sensordev_install(&sc->sc_sensordev);
printf("\n");
}
void
pcfadc_refresh(void *arg)
{
struct pcfadc_softc *sc = arg;
u_int i;
u_int8_t data[PCF8591_CHANNELS + 1];
iic_acquire_bus(sc->sc_tag, 0);
/* NB: first byte out is stale, so read num_channels + 1 */
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
NULL, 0, data, PCF8591_CHANNELS + 1, 0)) {
iic_release_bus(sc->sc_tag, 0);
return;
}
iic_release_bus(sc->sc_tag, 0);
/* XXX: so far this only supports temperature channels */
for (i = 0; i < sc->sc_nchan; i++) {
struct pcfadc_channel *chp = &sc->sc_channels[i];
chp->chan_sensor.value = 273150000 + 1000000 *
sc->sc_xlate[data[1 + chp->chan_num]];
}
}
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