svn commit: r350591 - in head: share/man/man4 sys/conf sys/dev/iicbus sys/modules/i2c sys/modules/i2c/ads111x

Ian Lepore ian at FreeBSD.org
Mon Aug 5 15:56:45 UTC 2019


Author: ian
Date: Mon Aug  5 15:56:44 2019
New Revision: 350591
URL: https://svnweb.freebsd.org/changeset/base/350591

Log:
  Add a driver for Texas Instruments ADS101x/ADS111x i2c ADC chips.
  
  Instances of the device can be configured using hints or FDT data.
  
  Interfaces to reconfigure the chip and extract voltage measurements from
  it are available via sysctl(8).

Added:
  head/share/man/man4/ads111x.4   (contents, props changed)
  head/sys/dev/iicbus/ads111x.c   (contents, props changed)
  head/sys/modules/i2c/ads111x/
  head/sys/modules/i2c/ads111x/Makefile   (contents, props changed)
Modified:
  head/sys/conf/NOTES
  head/sys/conf/files
  head/sys/modules/i2c/Makefile

Added: head/share/man/man4/ads111x.4
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/share/man/man4/ads111x.4	Mon Aug  5 15:56:44 2019	(r350591)
@@ -0,0 +1,240 @@
+.\"
+.\" Copyright (c) 2019 Ian Lepore <ian at freebsd.org>
+.\"
+.\" 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.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd August 5, 2019
+.Dt ADS1115 4
+.Os
+.Sh NAME
+.Nm ads1115
+.Nd driver for ADS101x and ADS111x i2c analog to digital converters
+.Sh SYNOPSIS
+To compile this driver into the kernel,
+place the following line in your
+kernel configuration file:
+.Bd -ragged -offset indent
+.Cd "device ads1115"
+.Ed
+.Pp
+Alternatively, to load the driver as a
+module at boot time, place the following line in
+.Xr loader.conf 5 :
+.Bd -literal -offset indent
+ads1115_load="YES"
+.Ed
+.Sh DESCRIPTION
+The
+.Nm
+driver provides support for the ADS101x/ADS111x family of analog
+to digital converter (ADC) devices.
+The supported devices are all similar to each other, varying in
+features such as resolution and number of input channels.
+The devices offer a number of configuration options which can be
+set via hints, FDT data, and
+.Xr sysctl 8 .
+.Pp
+.Xr Sysctl 8
+provides access to the voltage measurements made by the device.
+Each time the
+.Va dev.ads1115.<unit>.<channel>.voltage
+variable is accessed for a given channel, the driver switches the
+chip's internal mux to choose the right input pins for that channel,
+directs it to make a single measurement, and returns the measured value
+in microvolts.
+The amount of time required to make the measurement is a function
+of the sampling rate configured for the device.
+While device is directed to make a single measurement, it still averages
+the input values for the same amount of time as it would to emit one
+sample if it were in continuous mode.
+For example, if the sample rate were configured as 125 samples per
+second, a single measurement would require 8 milliseconds.
+.Pp
+For devices that support multiple input pins, the device datasheet
+describes mux settings to control how those pins are interpeted when
+making either single-ended or differential measurements.
+There are eight possible ways to combine the inputs from the four pins.
+The
+.Nm
+driver models that by creating a separate output channel for each of
+the eight combinations.
+To make a measurement on a given pin or pair of pins, you simply access
+the voltage variable for the channel number that corresponds the mux
+setting number (0 through 7) shown in the datasheet.
+When the driver is configured with hints or FDT data, it creates
+sysctl variables for just the channels specified in the config data.
+When there is no channel config data, it creates all eight possible
+channels so that you can access whichever one(s) you need.
+.Pp
+For devices that include an
+.Va alert
+output pin, the
+.Nm
+driver does not directly support the pin in terms of sensing or
+acting on changes in the pin state.
+However, you may connect the pin to a gpio input or fan controller
+or other external device, and use the driver's sysctl variables to
+configure behavior and threshold values for the pin.
+The driver avoids perturbing your settings as it does other
+manipulations to the config register.
+.Sh SYSCTL VARIABLES
+Sysctl variables are used to access the voltage measurements, and to
+change the configuration of the channels.
+All writeable variables may also be set as
+.Xr loader 8
+tunables.
+Channel numbers in these sysctl variables range from 0 through 7.
+.Bl -tag -width indent
+.It Va dev.ads1115.<unit>.config
+Provides access to the configuration register bits that control the
+alert pin configuration.
+Other bits which are controlled by the driver are masked out, and
+cannot be viewed or changed using this variable.
+.It Va dev.ads1115.<unit>.lo_thresh
+Sets the low threshold for activating the alert pin.
+.It Va dev.ads1115.<unit>.hi_thresh
+Sets the high threshold for activating the alert pin.
+.It Va dev.ads1115.<unit>.<channel>.rate_index
+Sets the sample rate for the channel.
+The device datasheet documents eight available sample rates, chosen
+by setting a value of 0 through 7 into the corresponding control
+register bits.
+This variable sets the value used for those bits when making a
+measurement on the given channel.
+.Pp
+Because measurements are always made in single-shot mode, think of
+this variable as controlling the averaging time for a single sample;
+the time to make a measurement is 1 / samplerate.
+.It Va dev.ads1115.<unit>.<channel>.gain_index
+Sets the programmable gain amplifier for the channel on devices
+which have an internal amplifier.
+The device datasheet documents eight available gain values, chosen
+by setting a value of 0 through 7 into the corresponding control
+register bits.
+This variable sets the value used for those bits when making a
+measurement on the given channel.
+.It Va dev.ads1115.<unit>.<channel>.voltage
+Reading this variable causes the device to make a measurement on
+the corresponding input pin(s) and return the voltage in microvolts.
+.Pp
+Note that this variable does not appear when you list multiple
+sysctl variables -- you must access it specifically by name, because
+accessing it triggers device I/O.
+.El
+.Sh HARDWARE
+The
+.Nm
+driver provides support for the following devices:
+.Pp
+.Bl -column -compact -offset indent "XXXXXXXX" "XXXXXXXX"
+.It ADS1013 Ta ADS1113
+.It ADS1014 Ta ADS1114
+.It ADS1015 Ta ADS1115
+.El
+.Sh FDT CONFIGURATION
+On an
+.Xr fdt 4
+based system, the
+.Nm
+device is defined as a slave device subnode
+of the i2c bus controller node.
+All properties documented in the
+.Va ads1115.txt
+bindings document can be used with the
+.Nm
+device.
+.Pp
+The following properties are required in the
+.Nm
+device subnode:
+.Bl -tag -width indent
+.It Va compatible
+One of the following:
+.Bl -column -compact -offset indent ".Dq ti,ads1013" ".Dq ti,ads1113"
+.It Dq ti,ads1013 Ta Dq ti,ads1113
+.It Dq ti,ads1014 Ta Dq ti,ads1114
+.It Dq ti,ads1015 Ta Dq ti,ads1115
+.El
+.It Va reg
+I2c slave address of device.
+.El
+.Pp
+Specific channels can be configured by adding child nodes to the
+.Nm
+node, as described in the standard ads1115.txt bindings document.
+If no channels are configured, sysctl variables will be created
+for all possible channels supported by the device type, otherwise
+only the specified channels are created.
+.Ss Example including channel configuration
+.Bd -unfilled -offset indent
+adc at 48 {
+    compatible = "ti,ads1115";
+    reg = <0x48>;
+    status = "okay";
+    #address-cells = <1>;
+    #size-cells = <0>;
+
+    channel at 6 {
+        reg = <6>;
+        ti,gain = <3>;
+        ti,datarate = <4>;
+    };
+    channel at 7 {
+        reg = <7>;
+        ti,gain = <1>;
+        ti,datarate = <7>;
+    };
+};
+.Ed
+.Sh HINTS CONFIGURATION
+On a
+.Xr device.hints 5
+based system, such as
+.Li MIPS ,
+these values are configurable for
+.Nm :
+.Bl -tag -width indent
+.It Va hint.ads1115.<unit>.at
+The iicbus instance the
+.Nm
+instance is attached to.
+.It Va hint.ads1115.<unit>.<channel>.gain_index
+The amplifier gain, as described above for the sysctl variable
+.Va dev.ads1115.<unit>.<channel>.gain_index .
+.It Va hint.ads1115.<unit>.<channel>.rate_index
+The sample rate, as described above for the sysctl variable
+.Va dev.ads1115.<unit>.<channel>.rate_index .
+.El
+.Pp
+If no channels are configured, sysctl variables will be created
+for all possible channels supported by the device type, otherwise
+only the specified channels are created.
+.Sh SEE ALSO
+.Xr fdt 4 ,
+.Xr sysctl 4
+.Sh HISTORY
+The
+.Nm
+driver first appeared in
+.Fx 13.0 .

Modified: head/sys/conf/NOTES
==============================================================================
--- head/sys/conf/NOTES	Mon Aug  5 15:24:05 2019	(r350590)
+++ head/sys/conf/NOTES	Mon Aug  5 15:56:44 2019	(r350591)
@@ -2422,6 +2422,7 @@ device		iicoc		# OpenCores I2C controller support
 # I2C peripheral devices
 #
 device		ad7418		# Analog Devices temp and voltage sensor
+device		ads111x		# Texas Instruments ADS101x and ADS111x ADCs
 device		ds1307		# Dallas DS1307 RTC and compatible
 device		ds13rtc		# All Dallas/Maxim ds13xx chips
 device		ds1672		# Dallas DS1672 RTC

Modified: head/sys/conf/files
==============================================================================
--- head/sys/conf/files	Mon Aug  5 15:24:05 2019	(r350590)
+++ head/sys/conf/files	Mon Aug  5 15:56:44 2019	(r350591)
@@ -1761,6 +1761,7 @@ dev/ida/ida.c			optional ida
 dev/ida/ida_disk.c		optional ida
 dev/ida/ida_pci.c		optional ida pci
 dev/iicbus/ad7418.c		optional ad7418
+dev/iicbus/ads111x.c		optional ads111x
 dev/iicbus/ds1307.c		optional ds1307
 dev/iicbus/ds13rtc.c		optional ds13rtc | ds133x | ds1374
 dev/iicbus/ds1672.c		optional ds1672

Added: head/sys/dev/iicbus/ads111x.c
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/dev/iicbus/ads111x.c	Mon Aug  5 15:56:44 2019	(r350591)
@@ -0,0 +1,582 @@
+/*-
+ * 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_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)
+#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},
+};
+IICBUS_FDT_PNP_INFO(compat_data);
+#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[2];
+
+	be16enc(data, val);
+
+	return (iic2errno(iicdev_writeto(sc->dev, reg, data, 2, 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, 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), and sleep at least that long.
+	 */
+	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);
+
+#if 0
+	/*
+	 * Sanity-check that the measurement is complete.  Not enabled by
+	 * default because checking wastes 200-800us just in moving the status
+	 * command and result across the i2c bus, which could double the time it
+	 * takes to get one measurement.  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.
+	 */
+	if ((err = ads111x_read_2(sc, ADS111x_CONF, &cfgword)) != 0)
+		return (err);
+	if (!(cfgword & ADS111x_CONF_IDLE))
+		return (EIO);
+#endif
+
+	/* 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, NULL, "channel data");
+	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(chantree), OID_AUTO,
+	    "gain_index", CTLTYPE_INT | CTLFLAG_RWTUN, 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, 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, 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) {
+		found = false;
+		gainidx = DEFAULT_GAINIDX;
+		rateidx = DEFAULT_RATEIDX;
+		if (resource_int_value(name, unit, "gain_index", &gainidx) == 0)
+			found = true;
+		if (resource_int_value(name, unit, "rate_index", &gainidx) == 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);
+		return (BUS_PROBE_DEFAULT);
+	}
+
+	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, sc, 0,
+	    ads111x_sysctl_config, "I", "configuration register word");
+	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
+	    "lo_thresh", CTLTYPE_INT | CTLFLAG_RWTUN, sc, 0,
+	    ads111x_sysctl_lothresh, "I", "comparator low threshold");
+	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
+	    "hi_thresh", CTLTYPE_INT | CTLFLAG_RWTUN, 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);
+MODULE_VERSION(ads111x, 1);
+MODULE_DEPEND(ads111x, iicbus, 1, 1, 1);

Modified: head/sys/modules/i2c/Makefile
==============================================================================
--- head/sys/modules/i2c/Makefile	Mon Aug  5 15:24:05 2019	(r350590)
+++ head/sys/modules/i2c/Makefile	Mon Aug  5 15:56:44 2019	(r350591)
@@ -1,6 +1,7 @@
 # $FreeBSD$
 
 SUBDIR = \
+	ads111x \
 	controllers \
 	cyapa \
 	ds1307 \

Added: head/sys/modules/i2c/ads111x/Makefile
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/modules/i2c/ads111x/Makefile	Mon Aug  5 15:56:44 2019	(r350591)
@@ -0,0 +1,15 @@
+# $FreeBSD$
+
+.PATH:		${SRCTOP}/sys/dev/iicbus
+
+KMOD=	ads111x
+SRCS=	ads111x.c
+
+SRCS+=	\
+	bus_if.h \
+	device_if.h \
+	iicbus_if.h \
+	ofw_bus_if.h \
+	opt_platform.h \
+
+.include <bsd.kmod.mk>


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