/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Ian Lepore.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
*/
/*
* Driver for Texas Instruments ADS101x and ADS111x family i2c ADC chips.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_platform.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#ifdef FDT
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbus_if.h"
/*
* Chip registers, bit definitions, shifting and masking values.
*/
#define ADS111x_CONV 0 /* Reg 0: Latest sample (ro) */
#define ADS111x_CONF 1 /* Reg 1: Config (rw) */
#define ADS111x_CONF_OS_SHIFT 15 /* Operational state */
#define ADS111x_CONF_MUX_SHIFT 12 /* Input mux setting */
#define ADS111x_CONF_GAIN_SHIFT 9 /* Programmable gain amp */
#define ADS111x_CONF_MODE_SHIFT 8 /* Operational mode */
#define ADS111x_CONF_RATE_SHIFT 5 /* Sample rate */
#define ADS111x_CONF_COMP_DISABLE 3 /* Comparator disable */
#define ADS111x_LOTHRESH 2 /* Compare lo threshold (rw) */
#define ADS111x_HITHRESH 3 /* Compare hi threshold (rw) */
/*
* On config write, the operational-state bit starts a measurement, on read it
* indicates when the measurement process is complete/idle.
*/
#define ADS111x_CONF_MEASURE (1u << ADS111x_CONF_OS_SHIFT)
#define ADS111x_CONF_IDLE (1u << ADS111x_CONF_OS_SHIFT)
/*
* The default values for config items that are not per-channel. Mostly, this
* turns off the comparator on chips that have that feature, because this driver
* doesn't support it directly. However, the user is allowed to enable the
* comparator and we'll leave it alone if they do. That allows them connect the
* alert pin to something and use the feature without any help from this driver.
*/
#define ADS111x_CONF_DEFAULT \
((1 << ADS111x_CONF_MODE_SHIFT) | ADS111x_CONF_COMP_DISABLE)
#define ADS111x_CONF_USERMASK 0x001f
/*
* Per-channel defaults. The chip only has one control register, and we load
* per-channel values into it every time we make a measurement on that channel.
* These are the default values for the control register from the datasheet, for
* values we maintain on a per-channel basis.
*/
#define DEFAULT_GAINIDX 2
#define DEFAULT_RATEIDX 4
/*
* Full-scale ranges for each available amplifier setting, in microvolts. The
* ADS1x13 chips are fixed-range, the other chips contain a programmable gain
* amplifier, and the full scale range is based on the amplifier setting.
*/
static const u_int fixedranges[8] = {
2048000, 2048000, 2048000, 2048000, 2048000, 2048000, 2048000, 2048000,
};
static const u_int gainranges[8] = {
6144000, 4096000, 2048000, 1024000, 512000, 256000, 256000, 256000,
};
/* The highest value for the ADS101x chip is 0x7ff0, for ADS111x it's 0x7fff. */
#define ADS101x_RANGEDIV ((1 << 15) - 15)
#define ADS111x_RANGEDIV ((1 << 15) - 1)
/* Samples per second; varies based on chip type. */
static const u_int rates101x[8] = {128, 250, 490, 920, 1600, 2400, 3300, 3300};
static const u_int rates111x[8] = { 8, 16, 32, 64, 128, 250, 475, 860};
struct ads111x_channel {
u_int gainidx; /* Amplifier (full-scale range) config index */
u_int rateidx; /* Samples per second config index */
bool configured; /* Channel has been configured */
};
#define ADS111x_MAX_CHANNELS 8
struct ads111x_chipinfo {
const char *name;
const u_int *rangetab;
const u_int *ratetab;
u_int numchan;
int rangediv;
};
static struct ads111x_chipinfo ads111x_chip_infos[] = {
{ "ADS1013", fixedranges, rates101x, 1, ADS101x_RANGEDIV },
{ "ADS1014", gainranges, rates101x, 1, ADS101x_RANGEDIV },
{ "ADS1015", gainranges, rates101x, 8, ADS101x_RANGEDIV },
{ "ADS1113", fixedranges, rates111x, 1, ADS111x_RANGEDIV },
{ "ADS1114", gainranges, rates111x, 1, ADS111x_RANGEDIV },
{ "ADS1115", gainranges, rates111x, 8, ADS111x_RANGEDIV },
};
#ifdef FDT
static struct ofw_compat_data compat_data[] = {
{"ti,ads1013", (uintptr_t)&ads111x_chip_infos[0]},
{"ti,ads1014", (uintptr_t)&ads111x_chip_infos[1]},
{"ti,ads1015", (uintptr_t)&ads111x_chip_infos[2]},
{"ti,ads1113", (uintptr_t)&ads111x_chip_infos[3]},
{"ti,ads1114", (uintptr_t)&ads111x_chip_infos[4]},
{"ti,ads1115", (uintptr_t)&ads111x_chip_infos[5]},
{NULL, (uintptr_t)NULL},
};
#endif
struct ads111x_softc {
device_t dev;
struct sx lock;
int addr;
int cfgword;
const struct ads111x_chipinfo
*chipinfo;
struct ads111x_channel
channels[ADS111x_MAX_CHANNELS];
};
static int
ads111x_write_2(struct ads111x_softc *sc, int reg, int val)
{
uint8_t data[3];
struct iic_msg msgs[1];
uint8_t slaveaddr;
slaveaddr = iicbus_get_addr(sc->dev);
data[0] = reg;
be16enc(&data[1], val);
msgs[0].slave = slaveaddr;
msgs[0].flags = IIC_M_WR;
msgs[0].len = sizeof(data);
msgs[0].buf = data;
return (iicbus_transfer_excl(sc->dev, msgs, nitems(msgs), IIC_WAIT));
}
static int
ads111x_read_2(struct ads111x_softc *sc, int reg, int *val)
{
int err;
uint8_t data[2];
err = iic2errno(iicdev_readfrom(sc->dev, reg, data, 2, IIC_WAIT));
if (err == 0)
*val = (int16_t)be16dec(data);
return (err);
}
static int
ads111x_sample_voltage(struct ads111x_softc *sc, int channum, int *voltage)
{
struct ads111x_channel *chan;
int err, cfgword, convword, rate, retries, waitns;
int64_t fsrange;
chan = &sc->channels[channum];
/* Ask the chip to do a one-shot measurement of the given channel. */
cfgword = sc->cfgword |
(1 << ADS111x_CONF_OS_SHIFT) |
(channum << ADS111x_CONF_MUX_SHIFT) |
(chan->gainidx << ADS111x_CONF_GAIN_SHIFT) |
(chan->rateidx << ADS111x_CONF_RATE_SHIFT);
if ((err = ads111x_write_2(sc, ADS111x_CONF, cfgword)) != 0)
return (err);
/*
* Calculate how long it will take to make the measurement at the
* current sampling rate (round up). The measurement averaging time
* ranges from 300us to 125ms, so we yield the cpu while waiting.
*/
rate = sc->chipinfo->ratetab[chan->rateidx];
waitns = (1000000000 + rate - 1) / rate;
err = pause_sbt("ads111x", nstosbt(waitns), 0, C_PREL(2));
if (err != 0 && err != EWOULDBLOCK)
return (err);
/*
* In theory the measurement should be available now; we waited long
* enough. However, the chip times its averaging intervals using an
* internal 1 MHz oscillator which likely isn't running at the same rate
* as the system clock, so we have to double-check that the measurement
* is complete before reading the result. If it's not ready yet, yield
* the cpu again for 5% of the time we originally calculated.
*
* Unlike most i2c slaves, this device does not auto-increment the
* register number on reads, so we can't read both status and
* measurement in one operation.
*/
for (retries = 5; ; --retries) {
if (retries == 0)
return (EWOULDBLOCK);
if ((err = ads111x_read_2(sc, ADS111x_CONF, &cfgword)) != 0)
return (err);
if (cfgword & ADS111x_CONF_IDLE)
break;
pause_sbt("ads111x", nstosbt(waitns / 20), 0, C_PREL(2));
}
/* Retrieve the sample and convert it to microvolts. */
if ((err = ads111x_read_2(sc, ADS111x_CONV, &convword)) != 0)
return (err);
fsrange = sc->chipinfo->rangetab[chan->gainidx];
*voltage = (int)((convword * fsrange ) / sc->chipinfo->rangediv);
return (err);
}
static int
ads111x_sysctl_gainidx(SYSCTL_HANDLER_ARGS)
{
struct ads111x_softc *sc;
int chan, err, gainidx;
sc = arg1;
chan = arg2;
gainidx = sc->channels[chan].gainidx;
err = sysctl_handle_int(oidp, &gainidx, 0, req);
if (err != 0 || req->newptr == NULL)
return (err);
if (gainidx < 0 || gainidx > 7)
return (EINVAL);
sx_xlock(&sc->lock);
sc->channels[chan].gainidx = gainidx;
sx_xunlock(&sc->lock);
return (err);
}
static int
ads111x_sysctl_rateidx(SYSCTL_HANDLER_ARGS)
{
struct ads111x_softc *sc;
int chan, err, rateidx;
sc = arg1;
chan = arg2;
rateidx = sc->channels[chan].rateidx;
err = sysctl_handle_int(oidp, &rateidx, 0, req);
if (err != 0 || req->newptr == NULL)
return (err);
if (rateidx < 0 || rateidx > 7)
return (EINVAL);
sx_xlock(&sc->lock);
sc->channels[chan].rateidx = rateidx;
sx_xunlock(&sc->lock);
return (err);
}
static int
ads111x_sysctl_voltage(SYSCTL_HANDLER_ARGS)
{
struct ads111x_softc *sc;
int chan, err, voltage;
sc = arg1;
chan = arg2;
if (req->oldptr != NULL) {
sx_xlock(&sc->lock);
err = ads111x_sample_voltage(sc, chan, &voltage);
sx_xunlock(&sc->lock);
if (err != 0) {
device_printf(sc->dev,
"conversion read failed, error %d\n", err);
return (err);
}
}
err = sysctl_handle_int(oidp, &voltage, 0, req);
return (err);
}
static int
ads111x_sysctl_config(SYSCTL_HANDLER_ARGS)
{
struct ads111x_softc *sc;
int config, err;
sc = arg1;
config = sc->cfgword & ADS111x_CONF_USERMASK;
err = sysctl_handle_int(oidp, &config, 0, req);
if (err != 0 || req->newptr == NULL)
return (err);
sx_xlock(&sc->lock);
sc->cfgword = config & ADS111x_CONF_USERMASK;
err = ads111x_write_2(sc, ADS111x_CONF, sc->cfgword);
sx_xunlock(&sc->lock);
return (err);
}
static int
ads111x_sysctl_lothresh(SYSCTL_HANDLER_ARGS)
{
struct ads111x_softc *sc;
int thresh, err;
sc = arg1;
if ((err = ads111x_read_2(sc, ADS111x_LOTHRESH, &thresh)) != 0)
return (err);
err = sysctl_handle_int(oidp, &thresh, 0, req);
if (err != 0 || req->newptr == NULL)
return (err);
sx_xlock(&sc->lock);
err = ads111x_write_2(sc, ADS111x_CONF, thresh);
sx_xunlock(&sc->lock);
return (err);
}
static int
ads111x_sysctl_hithresh(SYSCTL_HANDLER_ARGS)
{
struct ads111x_softc *sc;
int thresh, err;
sc = arg1;
if ((err = ads111x_read_2(sc, ADS111x_HITHRESH, &thresh)) != 0)
return (err);
err = sysctl_handle_int(oidp, &thresh, 0, req);
if (err != 0 || req->newptr == NULL)
return (err);
sx_xlock(&sc->lock);
err = ads111x_write_2(sc, ADS111x_CONF, thresh);
sx_xunlock(&sc->lock);
return (err);
}
static void
ads111x_setup_channel(struct ads111x_softc *sc, int chan, int gainidx, int rateidx)
{
struct ads111x_channel *c;
struct sysctl_ctx_list *ctx;
struct sysctl_oid *chantree, *devtree;
char chanstr[4];
c = &sc->channels[chan];
c->gainidx = gainidx;
c->rateidx = rateidx;
/*
* If setting up the channel for the first time, create channel's
* sysctl entries. We might have already configured the channel if
* config data for it exists in both FDT and hints.
*/
if (c->configured)
return;
ctx = device_get_sysctl_ctx(sc->dev);
devtree = device_get_sysctl_tree(sc->dev);
snprintf(chanstr, sizeof(chanstr), "%d", chan);
chantree = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(devtree), OID_AUTO,
chanstr, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "channel data");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(chantree), OID_AUTO,
"gain_index", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT,
sc, chan, ads111x_sysctl_gainidx, "I",
"programmable gain amp setting, 0-7");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(chantree), OID_AUTO,
"rate_index", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT,
sc, chan, ads111x_sysctl_rateidx, "I", "sample rate setting, 0-7");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(chantree), OID_AUTO,
"voltage",
CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_NEEDGIANT, sc,
chan, ads111x_sysctl_voltage, "I", "sampled voltage in microvolts");
c->configured = true;
}
static void
ads111x_add_channels(struct ads111x_softc *sc)
{
const char *name;
uint32_t chan, gainidx, num_added, rateidx, unit;
bool found;
#ifdef FDT
phandle_t child, node;
/* Configure any channels that have FDT data. */
num_added = 0;
node = ofw_bus_get_node(sc->dev);
for (child = OF_child(node); child != 0; child = OF_peer(child)) {
if (OF_getencprop(child, "reg", &chan, sizeof(chan)) == -1)
continue;
if (chan >= ADS111x_MAX_CHANNELS)
continue;
gainidx = DEFAULT_GAINIDX;
rateidx = DEFAULT_RATEIDX;
OF_getencprop(child, "ti,gain", &gainidx, sizeof(gainidx));
OF_getencprop(child, "ti,datarate", &rateidx, sizeof(rateidx));
ads111x_setup_channel(sc, chan, gainidx, rateidx);
++num_added;
}
#else
num_added = 0;
#endif
/* Configure any channels that have hint data. */
name = device_get_name(sc->dev);
unit = device_get_unit(sc->dev);
for (chan = 0; chan < sc->chipinfo->numchan; ++chan) {
char resname[16];
found = false;
gainidx = DEFAULT_GAINIDX;
rateidx = DEFAULT_RATEIDX;
snprintf(resname, sizeof(resname), "%d.gain_index", chan);
if (resource_int_value(name, unit, resname, &gainidx) == 0)
found = true;
snprintf(resname, sizeof(resname), "%d.rate_index", chan);
if (resource_int_value(name, unit, resname, &rateidx) == 0)
found = true;
if (found) {
ads111x_setup_channel(sc, chan, gainidx, rateidx);
++num_added;
}
}
/* If any channels were configured via FDT or hints, we're done. */
if (num_added > 0)
return;
/*
* No channel config; add all possible channels using default values,
* and let the user configure the ones they want on the fly via sysctl.
*/
for (chan = 0; chan < sc->chipinfo->numchan; ++chan) {
gainidx = DEFAULT_GAINIDX;
rateidx = DEFAULT_RATEIDX;
ads111x_setup_channel(sc, chan, gainidx, rateidx);
}
}
static const struct ads111x_chipinfo *
ads111x_find_chipinfo(device_t dev)
{
const struct ads111x_chipinfo *info;
const char *chiptype;
int i;
#ifdef FDT
if (ofw_bus_status_okay(dev)) {
info = (struct ads111x_chipinfo*)
ofw_bus_search_compatible(dev, compat_data)->ocd_data;
if (info != NULL)
return (info);
}
#endif
/* For hinted devices, we must be told the chip type. */
chiptype = NULL;
resource_string_value(device_get_name(dev), device_get_unit(dev),
"type", &chiptype);
if (chiptype != NULL) {
for (i = 0; i < nitems(ads111x_chip_infos); ++i) {
info = &ads111x_chip_infos[i];
if (strcasecmp(chiptype, info->name) == 0)
return (info);
}
}
return (NULL);
}
static int
ads111x_probe(device_t dev)
{
const struct ads111x_chipinfo *info;
info = ads111x_find_chipinfo(dev);
if (info != NULL) {
device_set_desc(dev, info->name);
#ifdef FDT
return (BUS_PROBE_DEFAULT);
#else
return (BUS_PROBE_NOWILDCARD);
#endif
}
return (ENXIO);
}
static int
ads111x_attach(device_t dev)
{
struct ads111x_softc *sc;
struct sysctl_ctx_list *ctx;
struct sysctl_oid *tree;
int err;
sc = device_get_softc(dev);
sc->dev = dev;
sc->addr = iicbus_get_addr(dev);
sc->cfgword = ADS111x_CONF_DEFAULT;
sc->chipinfo = ads111x_find_chipinfo(sc->dev);
if (sc->chipinfo == NULL) {
device_printf(dev,
"cannot get chipinfo (but it worked during probe)");
return (ENXIO);
}
/* Set the default chip config. */
if ((err = ads111x_write_2(sc, ADS111x_CONF, sc->cfgword)) != 0) {
device_printf(dev, "cannot write chip config register\n");
return (err);
}
/* Add the sysctl handler to set the chip configuration register. */
ctx = device_get_sysctl_ctx(dev);
tree = device_get_sysctl_tree(dev);
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"config", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, sc, 0,
ads111x_sysctl_config, "I", "configuration register word");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"lo_thresh", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, sc, 0,
ads111x_sysctl_lothresh, "I", "comparator low threshold");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"hi_thresh", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, sc, 0,
ads111x_sysctl_hithresh, "I", "comparator high threshold");
/* Set up channels based on metadata or default config. */
ads111x_add_channels(sc);
sx_init(&sc->lock, "ads111x");
return (0);
}
static int
ads111x_detach(device_t dev)
{
struct ads111x_softc *sc;
sc = device_get_softc(dev);
sx_destroy(&sc->lock);
return (0);
}
static device_method_t ads111x_methods[] = {
DEVMETHOD(device_probe, ads111x_probe),
DEVMETHOD(device_attach, ads111x_attach),
DEVMETHOD(device_detach, ads111x_detach),
DEVMETHOD_END,
};
static driver_t ads111x_driver = {
"ads111x",
ads111x_methods,
sizeof(struct ads111x_softc),
};
static devclass_t ads111x_devclass;
DRIVER_MODULE(ads111x, iicbus, ads111x_driver, ads111x_devclass, NULL, NULL);
#ifdef FDT
IICBUS_FDT_PNP_INFO(compat_data);
#endif
MODULE_VERSION(ads111x, 1);
MODULE_DEPEND(ads111x, iicbus, 1, 1, 1);
