bmp085: driver for the BMP085 temp&pressure sensor
Change-Id: I5c297a7f4f8cea2549e537df30a5c7bf5b9d8b51
This commit is contained in:
Thomas Cort
parent
3bdd1ae659
commit
471dc65ada
8 changed files with 893 additions and 3 deletions
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@ -32,7 +32,8 @@ case $#:$1 in
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eepromb3s50 eepromb3s51 eepromb3s52 eepromb3s53 \
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eepromb3s54 eepromb3s55 eepromb3s56 eepromb3s57 \
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tsl2550b1s39 tsl2550b2s39 tsl2550b3s39 \
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sht21b1s40 sht21b2s40 sht21b3s40
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sht21b1s40 sht21b2s40 sht21b3s40 \
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bmp085b1s77 bmp085b2s77 bmp085b3s77
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;;
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0:|1:-\?)
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cat >&2 <<EOF
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@ -43,6 +44,7 @@ Where key is one of the following:
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i2c-1 i2c-2 i2c-3 # Make /dev/i2c-[1-3]
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tsl2550b{1,3}s39 # TSL2550 Ambient Light Sensors
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sht21b{1,3}s40 # SHT21 Relative Humidity and Temperature Sensors
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bmp085b{1,3}s77 # BMP085 Pressure and Temperature Sensors
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fd0 fd1 ... # Floppy devices for drive 0, 1, ...
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fd0p0 fd1p0 ... # Make floppy partitions fd0p[0-3], fd1p[0-3], ...
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c0d0 c0d1 ... # Make disks c0d0, c0d1, ...
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@ -323,7 +325,12 @@ do
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$e mknod sht21b${b}s40 c ${m} 0
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$e chmod 444 sht21b${b}s40
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;;
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bmp085b[1-3]s77)
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b=`expr $dev : 'bmp085b\\(.*\\)s77'` #bus number
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m=`expr ${b} + 52`
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$e mknod bmp085b${b}s77 c ${m} 0
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$e chmod 444 bmp085b${b}s77
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;;
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*)
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echo "$0: don't know about $dev" >&2
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ex=1
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@ -105,6 +105,7 @@
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./usr/lib/libpadconf_pic.a minix-sys
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./usr/man/man1/eepromread.1 minix-sys
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./usr/mdec minix-sys
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./usr/sbin/bmp085 minix-sys
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./usr/sbin/cat24c256 minix-sys
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./usr/sbin/fb minix-sys
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./usr/sbin/gpio minix-sys
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@ -23,7 +23,7 @@ SUBDIR= ahci amddev atl2 at_wini audio dec21140A dp8390 dpeth \
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.endif
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.if ${MACHINE_ARCH} == "earm"
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SUBDIR= cat24c256 fb gpio i2c mmc lan8710a log readclock \
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SUBDIR= bmp085 cat24c256 fb gpio i2c mmc lan8710a log readclock \
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sht21 tda19988 tps65217 tps65950 tsl2550 tty random
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.endif
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14
drivers/bmp085/Makefile
Normal file
14
drivers/bmp085/Makefile
Normal file
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@ -0,0 +1,14 @@
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# Makefile for the bmp085 pressure and temp sensor found on the Weather Cape.
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PROG= bmp085
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SRCS= bmp085.c
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DPADD+= ${LIBI2CDRIVER} ${LIBCHARDRIVER} ${LIBSYS} ${LIBTIMERS}
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LDADD+= -li2cdriver -lchardriver -lsys -ltimers
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MAN=
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BINDIR?= /usr/sbin
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CPPFLAGS+= -I${NETBSDSRCDIR}
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.include <minix.service.mk>
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63
drivers/bmp085/README.txt
Normal file
63
drivers/bmp085/README.txt
Normal file
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@ -0,0 +1,63 @@
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BMP085 Driver (Pressure and Temperature Sensor)
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===============================================
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Overview
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--------
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This is the driver for the pressure and temperature sensor commonly found on
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the WeatherCape expansion board for the BeagleBone.
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Interface
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---------
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This driver implements the character device interface. It supports reading
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through /dev/bmp085b{1,3}s77. When read from, it returns a string containing
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a data label, a colon, and the sensor value.
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Example output of `cat /dev/bmp085b3s77`:
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TEMPERATURE : 23.1
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PRESSURE : 69964
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Temperature is expressed in Celsius (a.k.a. centigrade). The resolution is
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0.1C.
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Pressure is expressed in Pascals. Valid values are 30000 to 110000.
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The resolution is 3 Pa.
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Limitations
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-----------
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The measurement resolution is configurable in the chip, but this driver just
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uses standard mode. It could probably be implemented with an ioctl() or by
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passing an argument via the service command, but it doesn't seem too useful at
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this time. See the data sheet for the trade-offs between conversion time,
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power consumption, and resolution.
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While only the BMP085 is supported at present, the BMP085's predecessor,
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SMD500, should be easy to support in this driver with some small changes
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to the calculations and coefficients.
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As with the SHT21's temperature sensor, the BMP085's temperature sensor
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appears to be heated a couple of degrees by the BeagleBone. After power-on,
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the readings rise slightly and then level off a few degrees above room
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temperature.
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Testing the Code
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----------------
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The driver should have been started by a script in /etc/rc.capes/ If not,
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this is how you start up an instance:
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cd /dev && MAKEDEV bmp085b3s77
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/bin/service up /usr/sbin/bmp085 -label bmp085.3.77 -dev /dev/bmp085b3s77 \
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-args 'bus=3 address=0x77'
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Getting the sensor value:
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cat /dev/bmp085b3s77
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Killing an instance:
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/bin/service down bmp085.3.77
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After Width: | Height: | Size: 1.9 KiB |
797
drivers/bmp085/bmp085.c
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797
drivers/bmp085/bmp085.c
Normal file
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@ -0,0 +1,797 @@
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/* Driver for the BMP085 Preassure and Temperature Sensor */
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#include <minix/ds.h>
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#include <minix/drivers.h>
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#include <minix/i2c.h>
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#include <minix/i2cdriver.h>
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#include <minix/chardriver.h>
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#include <minix/log.h>
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/* Control Register for triggering a measurement */
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#define CTRL_REG 0xf4
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/* temperature sensor - it only has one 'mode' - conversion time 4.5 ms */
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#define CMD_TRIG_T 0x2e
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#define UDELAY_T (4500)
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/* pressure sensor - ultra low power mode - conversion time 4.5 ms */
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#define CMD_TRIG_P_ULP 0x34
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#define MODE_ULP 0x00
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#define UDELAY_ULP (4500)
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/* pressure sensor - standard mode - conversion time 7.5 ms */
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#define CMD_TRIG_P_STD 0x74
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#define MODE_STD 0x01
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#define UDELAY_STD (7500)
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/* pressure sensor - high resolution mode - conversion time 13.5 ms */
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#define CMD_TRIG_P_HR 0xb4
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#define MODE_HR 0x02
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#define UDELAY_HR (13500)
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/* pressure sensor - ultra high resolution mode - conversion time 25.5 ms */
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#define CMD_TRIG_P_UHR 0xf4
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#define MODE_UHR 0x03
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#define UDELAY_UHR (25500)
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/* Values for the different modes of operation */
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struct pressure_cmd
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{
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uint8_t cmd;
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uint8_t mode;
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uint16_t udelay;
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};
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/* Table of available modes and their parameters. */
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static struct pressure_cmd pressure_cmds[4] = {
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{CMD_TRIG_P_ULP, MODE_ULP, UDELAY_ULP},
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{CMD_TRIG_P_STD, MODE_STD, UDELAY_STD},
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{CMD_TRIG_P_HR, MODE_HR, UDELAY_HR},
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{CMD_TRIG_P_UHR, MODE_UHR, UDELAY_UHR}
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};
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/* Default to standard mode.
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* There isn't code to configure the resolution at runtime, but it should
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* easy to implement by setting p_cmd to the right element of pressure_cmds.
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*/
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static struct pressure_cmd *p_cmd = &pressure_cmds[MODE_STD];
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/* Chip Identification */
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#define CHIPID_REG 0xd0
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#define BMP085_CHIPID 0x55
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/*
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* There is also a version register at 0xd1, but documentation seems to be
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* lacking. The sample code says high 4 bytes are AL version and low 4 are ML.
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*/
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/* Calibration coefficients
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*
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* These are unique to each chip and must be read when starting the driver.
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* Validate them by checking that none are 0x0000 nor 0xffff. Types and
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* names are from the datasheet.
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*/
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struct calibration
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{
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int16_t ac1;
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int16_t ac2;
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int16_t ac3;
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uint16_t ac4;
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uint16_t ac5;
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uint16_t ac6;
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int16_t b1;
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int16_t b2;
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int16_t mb;
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int16_t mc;
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int16_t md;
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} cal;
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/* Register locations for calibration coefficients */
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#define AC1_MSB_REG 0xaa
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#define AC1_LSB_REG 0xab
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#define AC2_MSB_REG 0xac
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#define AC2_LSB_REG 0xad
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#define AC3_MSB_REG 0xae
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#define AC3_LSB_REG 0xaf
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#define AC4_MSB_REG 0xb0
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#define AC4_LSB_REG 0xb1
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#define AC5_MSB_REG 0xb2
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#define AC5_LSB_REG 0xb3
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#define AC6_MSB_REG 0xb4
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#define AC6_LSB_REG 0xb5
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#define B1_MSB_REG 0xb6
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#define B1_LSB_REG 0xb7
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#define B2_MSB_REG 0xb8
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#define B2_LSB_REG 0xb9
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#define MB_MSB_REG 0xba
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#define MB_LSB_REG 0xbb
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#define MC_MSB_REG 0xbc
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#define MC_LSB_REG 0xbd
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#define MD_MSB_REG 0xbe
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#define MD_LSB_REG 0xbf
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#define CAL_COEF_FIRST AC1_MSB_REG
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#define CAL_COEF_LAST MD_LSB_REG
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#define CAL_COEF_IS_VALID(x) (x != 0x0000 && x != 0xffff)
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#define SENSOR_VAL_MSB_REG 0xf6
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#define SENSOR_VAL_LSB_REG 0xf7
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#define SENSOR_VAL_XLSB_REG 0xf8
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/* logging - use with log_warn(), log_info(), log_debug(), log_trace(), etc */
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static struct log log = {
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.name = "bmp085",
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.log_level = LEVEL_INFO,
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.log_func = default_log
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};
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/* Only one valid slave address. It isn't configurable. */
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static i2c_addr_t valid_addrs[5] = {
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0x77, 0x00
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};
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/* Buffer to store output string returned when reading from device file. */
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#define BUFFER_LEN 64
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char buffer[BUFFER_LEN + 1];
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/* the bus that this device is on (counting starting at 1) */
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static uint32_t bus;
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/* slave address of the device */
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static i2c_addr_t address;
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/* endpoint for the driver for the bus itself. */
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static endpoint_t bus_endpoint;
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/* main device functions */
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static int bmp085_init(void);
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static int version_check(void);
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static int read_cal_coef(void);
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static int measure(int32_t * temperature, int32_t * pressure);
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/* libchardriver callbacks */
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static struct device *bmp085_prepare(dev_t UNUSED(dev));
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static int bmp085_transfer(endpoint_t endpt, int opcode, u64_t position,
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iovec_t * iov, unsigned nr_req, endpoint_t UNUSED(user_endpt),
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unsigned int UNUSED(flags));
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static int bmp085_other(message * m);
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/* i2c bus access */
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static int reg_read(uint8_t reg, uint8_t * val);
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static int reg_read16(uint8_t reg, uint16_t * val);
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static int reg_read24(uint8_t reg, uint32_t * val);
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static int reg_write(uint8_t reg, uint8_t val);
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/* SEF Function */
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static int sef_cb_lu_state_save(int);
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static int lu_state_restore(void);
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static int sef_cb_init(int type, sef_init_info_t * info);
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static void sef_local_startup(void);
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/* Entry points to this driver from libchardriver. */
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static struct chardriver bmp085_tab = {
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.cdr_open = do_nop,
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.cdr_close = do_nop,
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.cdr_ioctl = nop_ioctl,
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.cdr_prepare = bmp085_prepare,
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.cdr_transfer = bmp085_transfer,
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.cdr_cleanup = nop_cleanup,
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.cdr_alarm = nop_alarm,
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.cdr_cancel = nop_cancel,
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.cdr_select = nop_select,
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.cdr_other = bmp085_other
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};
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static struct device bmp085_device = {
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.dv_base = 0,
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.dv_size = 0
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};
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static int
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reg_read(uint8_t reg, uint8_t * val)
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{
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int r;
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minix_i2c_ioctl_exec_t ioctl_exec;
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if (val == NULL) {
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log_warn(&log, "reg_read() called with NULL pointer\n");
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return -1;
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}
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memset(&ioctl_exec, '\0', sizeof(minix_i2c_ioctl_exec_t));
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/* Read from chip */
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ioctl_exec.iie_op = I2C_OP_READ_WITH_STOP;
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ioctl_exec.iie_addr = address;
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/* write the register address */
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ioctl_exec.iie_cmd[0] = reg;
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ioctl_exec.iie_cmdlen = 1;
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/* read 1 byte */
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ioctl_exec.iie_buflen = 1;
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r = i2cdriver_exec(bus_endpoint, &ioctl_exec);
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if (r != OK) {
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log_warn(&log, "reg_read() failed (r=%d)\n", r);
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return -1;
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}
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*val = ioctl_exec.iie_buf[0];
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log_trace(&log, "Read 0x%x from reg 0x%x\n", *val, reg);
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return OK;
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}
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static int
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reg_read16(uint8_t reg, uint16_t * val)
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{
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int r;
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uint8_t msb, lsb;
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minix_i2c_ioctl_exec_t ioctl_exec;
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if (val == NULL) {
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log_warn(&log, "reg_read16() called with NULL pointer\n");
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return -1;
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}
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memset(&ioctl_exec, '\0', sizeof(minix_i2c_ioctl_exec_t));
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/* Read from chip */
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ioctl_exec.iie_op = I2C_OP_READ_WITH_STOP;
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ioctl_exec.iie_addr = address;
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/* write the register address */
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ioctl_exec.iie_cmd[0] = reg;
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ioctl_exec.iie_cmdlen = 1;
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/* read 2 bytes */
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ioctl_exec.iie_buflen = 2;
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r = i2cdriver_exec(bus_endpoint, &ioctl_exec);
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if (r != OK) {
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log_warn(&log, "reg_read16() failed (r=%d)\n", r);
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return -1;
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}
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msb = ioctl_exec.iie_buf[0];
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lsb = ioctl_exec.iie_buf[1];
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*val = ((msb << 8) | lsb);
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log_trace(&log, "Read 0x%x from reg 0x%x\n", *val, reg);
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return OK;
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}
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static int
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reg_read24(uint8_t reg, uint32_t * val)
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{
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int r;
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uint8_t msb, lsb, xlsb;
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minix_i2c_ioctl_exec_t ioctl_exec;
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if (val == NULL) {
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log_warn(&log, "reg_read24() called with NULL pointer\n");
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return -1;
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}
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memset(&ioctl_exec, '\0', sizeof(minix_i2c_ioctl_exec_t));
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/* Read from chip */
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ioctl_exec.iie_op = I2C_OP_READ_WITH_STOP;
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ioctl_exec.iie_addr = address;
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/* write the register address */
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ioctl_exec.iie_cmd[0] = reg;
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ioctl_exec.iie_cmdlen = 1;
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/* read 3 bytes */
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ioctl_exec.iie_buflen = 3;
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r = i2cdriver_exec(bus_endpoint, &ioctl_exec);
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if (r != OK) {
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log_warn(&log, "reg_read24() failed (r=%d)\n", r);
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return -1;
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}
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msb = ioctl_exec.iie_buf[0];
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lsb = ioctl_exec.iie_buf[1];
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xlsb = ioctl_exec.iie_buf[2];
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*val = ((msb << 16) | (lsb << 8) | xlsb);
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log_trace(&log, "Read 0x%x from reg 0x%x\n", *val, reg);
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return OK;
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}
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static int
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reg_write(uint8_t reg, uint8_t val)
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||||
{
|
||||
int r;
|
||||
minix_i2c_ioctl_exec_t ioctl_exec;
|
||||
|
||||
memset(&ioctl_exec, '\0', sizeof(minix_i2c_ioctl_exec_t));
|
||||
|
||||
/* Read from chip */
|
||||
ioctl_exec.iie_op = I2C_OP_WRITE_WITH_STOP;
|
||||
ioctl_exec.iie_addr = address;
|
||||
|
||||
/* no commands here */
|
||||
ioctl_exec.iie_cmdlen = 0;
|
||||
|
||||
/* write register and value */
|
||||
ioctl_exec.iie_buf[0] = reg;
|
||||
ioctl_exec.iie_buf[1] = val;
|
||||
ioctl_exec.iie_buflen = 2;
|
||||
|
||||
r = i2cdriver_exec(bus_endpoint, &ioctl_exec);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "reg_write() failed (r=%d)\n", r);
|
||||
return -1;
|
||||
}
|
||||
|
||||
log_trace(&log, "Wrote 0x%x to reg 0x%x\n", val, reg);
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
/*
|
||||
* Initialize the driver. Checks the CHIPID against a known value and
|
||||
* reads the calibration coefficients.
|
||||
*
|
||||
* The chip does have a soft reset register (0xe0), but there
|
||||
* doesn't appear to be any documentation or example usage for it.
|
||||
*/
|
||||
static int
|
||||
bmp085_init(void)
|
||||
{
|
||||
int r;
|
||||
int32_t t, p;
|
||||
|
||||
r = version_check();
|
||||
if (r != OK) {
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
r = read_cal_coef();
|
||||
if (r != OK) {
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
static int
|
||||
version_check(void)
|
||||
{
|
||||
int r;
|
||||
uint8_t chipid;
|
||||
|
||||
r = reg_read(CHIPID_REG, &chipid);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Couldn't read CHIPID\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (chipid != BMP085_CHIPID) {
|
||||
log_warn(&log, "Bad CHIPID\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
log_debug(&log, "CHIPID OK\n");
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
/*
|
||||
* Read the calibration data from the chip. Each individual chip has a unique
|
||||
* set of calibration parameters that get used to compute the true temperature
|
||||
* and pressure.
|
||||
*/
|
||||
static int
|
||||
read_cal_coef(void)
|
||||
{
|
||||
int r;
|
||||
|
||||
/* Populate the calibration struct with values */
|
||||
r = reg_read16(AC1_MSB_REG, &cal.ac1);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.ac1 = %d\n", cal.ac1);
|
||||
|
||||
r = reg_read16(AC2_MSB_REG, &cal.ac2);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.ac2 = %d\n", cal.ac2);
|
||||
|
||||
r = reg_read16(AC3_MSB_REG, &cal.ac3);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.ac3 = %d\n", cal.ac3);
|
||||
|
||||
r = reg_read16(AC4_MSB_REG, &cal.ac4);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.ac4 = %u\n", cal.ac4);
|
||||
|
||||
r = reg_read16(AC5_MSB_REG, &cal.ac5);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.ac5 = %u\n", cal.ac5);
|
||||
|
||||
r = reg_read16(AC6_MSB_REG, &cal.ac6);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.ac6 = %u\n", cal.ac6);
|
||||
|
||||
r = reg_read16(B1_MSB_REG, &cal.b1);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.b1 = %d\n", cal.b1);
|
||||
|
||||
r = reg_read16(B2_MSB_REG, &cal.b2);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.b2 = %d\n", cal.b2);
|
||||
|
||||
r = reg_read16(MB_MSB_REG, &cal.mb);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.mb = %d\n", cal.mb);
|
||||
|
||||
r = reg_read16(MC_MSB_REG, &cal.mc);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.mc = %d\n", cal.mc);
|
||||
|
||||
r = reg_read16(MD_MSB_REG, &cal.md);
|
||||
if (r != OK) {
|
||||
return -1;
|
||||
}
|
||||
log_debug(&log, "cal.md = %d\n", cal.md);
|
||||
|
||||
/* Validate. Data sheet says values should not be 0x0000 nor 0xffff */
|
||||
if (!CAL_COEF_IS_VALID(cal.ac1) ||
|
||||
!CAL_COEF_IS_VALID(cal.ac2) ||
|
||||
!CAL_COEF_IS_VALID(cal.ac3) ||
|
||||
!CAL_COEF_IS_VALID(cal.ac4) ||
|
||||
!CAL_COEF_IS_VALID(cal.ac5) ||
|
||||
!CAL_COEF_IS_VALID(cal.ac6) ||
|
||||
!CAL_COEF_IS_VALID(cal.b1) ||
|
||||
!CAL_COEF_IS_VALID(cal.b2) ||
|
||||
!CAL_COEF_IS_VALID(cal.mb) ||
|
||||
!CAL_COEF_IS_VALID(cal.mc) || !CAL_COEF_IS_VALID(cal.md)) {
|
||||
|
||||
log_warn(&log, "Invalid calibration data found on chip.\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
log_debug(&log, "Read Cal Data OK\n");
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
/*
|
||||
* Measure the uncompensated temperature and uncompensated pressure from the
|
||||
* chip and apply the formulas to determine the true temperature and pressure.
|
||||
* Note, the data sheet is light on the details when it comes to defining the
|
||||
* meaning of each variable, so this function has a lot of cryptic names in it.
|
||||
*/
|
||||
static int
|
||||
measure(int32_t * temperature, int32_t * pressure)
|
||||
{
|
||||
int r;
|
||||
|
||||
/* Types are given in the datasheet. Their long translates to 32-bits */
|
||||
|
||||
int16_t ut; /* uncompensated temperature */
|
||||
int32_t up; /* uncompensated pressure */
|
||||
int32_t x1;
|
||||
int32_t x2;
|
||||
int32_t x3;
|
||||
int32_t b3;
|
||||
uint32_t b4;
|
||||
int32_t b5;
|
||||
int32_t b6;
|
||||
uint32_t b7;
|
||||
int32_t t; /* true temperature (in 0.1C) */
|
||||
int32_t p; /* true pressure (in Pa) */
|
||||
|
||||
log_debug(&log, "Triggering Temp Reading...\n");
|
||||
|
||||
/* trigger temperature reading */
|
||||
r = reg_write(CTRL_REG, CMD_TRIG_T);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Failed to trigger temperature reading.\n");
|
||||
return -1;
|
||||
}
|
||||
micro_delay(UDELAY_T);
|
||||
|
||||
/* trigger temperature reading */
|
||||
r = reg_write(CTRL_REG, CMD_TRIG_T);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Failed to trigger temperature reading.\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* wait for sampling to be completed. */
|
||||
micro_delay(UDELAY_T);
|
||||
|
||||
/* read the uncompensated temperature */
|
||||
r = reg_read16(SENSOR_VAL_MSB_REG, &ut);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Failed to read temperature.\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
log_debug(&log, "ut = %d\n", ut);
|
||||
|
||||
log_debug(&log, "Triggering Pressure Reading...\n");
|
||||
|
||||
/* trigger pressure reading */
|
||||
r = reg_write(CTRL_REG, p_cmd->cmd);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Failed to trigger pressure reading.\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* wait for sampling to be completed. */
|
||||
micro_delay(p_cmd->udelay);
|
||||
|
||||
/* read the uncompensated pressure */
|
||||
r = reg_read24(SENSOR_VAL_MSB_REG, &up);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Failed to read pressure.\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* shift by 8 - oversampling setting */
|
||||
up = (up >> (8 - p_cmd->mode));
|
||||
|
||||
log_debug(&log, "up = %d\n", up);
|
||||
|
||||
/* convert uncompensated temperature to true temperature */
|
||||
x1 = ((ut - cal.ac6) * cal.ac5) / (1 << 15);
|
||||
x2 = (cal.mc * (1 << 11)) / (x1 + cal.md);
|
||||
b5 = x1 + x2;
|
||||
t = (b5 + 8) / (1 << 4);
|
||||
|
||||
/* save the result */
|
||||
*temperature = t;
|
||||
|
||||
log_debug(&log, "t = %d\n", t);
|
||||
|
||||
/* Convert uncompensated pressure to true pressure.
|
||||
* This is really how the data sheet suggests doing it.
|
||||
* There is no alternative approach suggested. Other open
|
||||
* source drivers I've found use this method.
|
||||
*/
|
||||
b6 = b5 - 4000;
|
||||
x1 = ((cal.b2 * ((b6 * b6) >> 12)) >> 11);
|
||||
x2 = ((cal.ac2 * b6) >> 11);
|
||||
x3 = x1 + x2;
|
||||
b3 = (((((cal.ac1 * 4) + x3) << p_cmd->mode) + 2) >> 2);
|
||||
x1 = ((cal.ac3 * b6) >> 13);
|
||||
x2 = ((cal.b1 * ((b6 * b6) >> 12)) >> 16);
|
||||
x3 = (((x1 + x2) + 2) >> 2);
|
||||
b4 = ((cal.ac4 * ((uint32_t) (x3 + 32768))) >> 15);
|
||||
b7 = ((uint32_t) up - b3) * (50000 >> p_cmd->mode);
|
||||
p = (b7 < 0x80000000) ? (b7 * 2) / b4 : (b7 / b4) * 2;
|
||||
x1 = (p >> 8) * (p >> 8);
|
||||
x1 = ((x1 * 3038) >> 16);
|
||||
x2 = ((-7357 * p) >> 16);
|
||||
p = p + ((x1 + x2 + 3791) >> 4);
|
||||
|
||||
*pressure = p;
|
||||
|
||||
log_debug(&log, "p = %d\n", p);
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
static struct device *
|
||||
bmp085_prepare(dev_t UNUSED(dev))
|
||||
{
|
||||
return &bmp085_device;
|
||||
}
|
||||
|
||||
static int
|
||||
bmp085_transfer(endpoint_t endpt, int opcode, u64_t position,
|
||||
iovec_t * iov, unsigned nr_req, endpoint_t UNUSED(user_endpt),
|
||||
unsigned int UNUSED(flags))
|
||||
{
|
||||
int bytes, r;
|
||||
uint32_t temperature, pressure;
|
||||
|
||||
r = measure(&temperature, &pressure);
|
||||
if (r != OK) {
|
||||
return EIO;
|
||||
}
|
||||
|
||||
memset(buffer, '\0', BUFFER_LEN + 1);
|
||||
snprintf(buffer, BUFFER_LEN, "%-16s: %d.%01d\n%-16s: %d\n",
|
||||
"TEMPERATURE", temperature / 10, temperature % 10, "PRESSURE",
|
||||
pressure);
|
||||
|
||||
log_trace(&log, "%s", buffer);
|
||||
|
||||
bytes = strlen(buffer) - position < iov->iov_size ?
|
||||
strlen(buffer) - position : iov->iov_size;
|
||||
|
||||
if (bytes <= 0) {
|
||||
return OK;
|
||||
}
|
||||
|
||||
switch (opcode) {
|
||||
case DEV_GATHER_S:
|
||||
r = sys_safecopyto(endpt, (cp_grant_id_t) iov->iov_addr, 0,
|
||||
(vir_bytes) (buffer + position), bytes);
|
||||
iov->iov_size -= bytes;
|
||||
break;
|
||||
default:
|
||||
return EINVAL;
|
||||
}
|
||||
|
||||
return r;
|
||||
}
|
||||
|
||||
static int
|
||||
bmp085_other(message * m)
|
||||
{
|
||||
int r;
|
||||
|
||||
switch (m->m_type) {
|
||||
case NOTIFY_MESSAGE:
|
||||
if (m->m_source == DS_PROC_NR) {
|
||||
log_debug(&log,
|
||||
"bus driver changed state, update endpoint\n");
|
||||
i2cdriver_handle_bus_update(&bus_endpoint, bus,
|
||||
address);
|
||||
}
|
||||
r = OK;
|
||||
break;
|
||||
default:
|
||||
log_warn(&log, "Invalid message type (0x%x)\n", m->m_type);
|
||||
r = EINVAL;
|
||||
break;
|
||||
}
|
||||
|
||||
return r;
|
||||
}
|
||||
|
||||
static int
|
||||
sef_cb_lu_state_save(int UNUSED(state))
|
||||
{
|
||||
ds_publish_u32("bus", bus, DSF_OVERWRITE);
|
||||
ds_publish_u32("address", address, DSF_OVERWRITE);
|
||||
return OK;
|
||||
}
|
||||
|
||||
static int
|
||||
lu_state_restore(void)
|
||||
{
|
||||
/* Restore the state. */
|
||||
u32_t value;
|
||||
|
||||
ds_retrieve_u32("bus", &value);
|
||||
ds_delete_u32("bus");
|
||||
bus = (int) value;
|
||||
|
||||
ds_retrieve_u32("address", &value);
|
||||
ds_delete_u32("address");
|
||||
address = (int) value;
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
static int
|
||||
sef_cb_init(int type, sef_init_info_t * UNUSED(info))
|
||||
{
|
||||
int r;
|
||||
|
||||
if (type == SEF_INIT_LU) {
|
||||
/* Restore the state. */
|
||||
lu_state_restore();
|
||||
}
|
||||
|
||||
/* look-up the endpoint for the bus driver */
|
||||
bus_endpoint = i2cdriver_bus_endpoint(bus);
|
||||
if (bus_endpoint == 0) {
|
||||
log_warn(&log, "Couldn't find bus driver.\n");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
/* claim the device */
|
||||
r = i2cdriver_reserve_device(bus_endpoint, address);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Couldn't reserve device 0x%x (r=%d)\n",
|
||||
address, r);
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
r = bmp085_init();
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Couldn't initialize device\n");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
if (type != SEF_INIT_LU) {
|
||||
|
||||
/* sign up for updates about the i2c bus going down/up */
|
||||
r = i2cdriver_subscribe_bus_updates(bus);
|
||||
if (r != OK) {
|
||||
log_warn(&log, "Couldn't subscribe to bus updates\n");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
i2cdriver_announce(bus);
|
||||
log_debug(&log, "announced\n");
|
||||
}
|
||||
|
||||
return OK;
|
||||
}
|
||||
|
||||
static void
|
||||
sef_local_startup(void)
|
||||
{
|
||||
/*
|
||||
* Register init callbacks. Use the same function for all event types
|
||||
*/
|
||||
sef_setcb_init_fresh(sef_cb_init);
|
||||
sef_setcb_init_lu(sef_cb_init);
|
||||
sef_setcb_init_restart(sef_cb_init);
|
||||
|
||||
/*
|
||||
* Register live update callbacks.
|
||||
*/
|
||||
/* Agree to update immediately when LU is requested in a valid state. */
|
||||
sef_setcb_lu_prepare(sef_cb_lu_prepare_always_ready);
|
||||
/* Support live update starting from any standard state. */
|
||||
sef_setcb_lu_state_isvalid(sef_cb_lu_state_isvalid_standard);
|
||||
/* Register a custom routine to save the state. */
|
||||
sef_setcb_lu_state_save(sef_cb_lu_state_save);
|
||||
|
||||
/* Let SEF perform startup. */
|
||||
sef_startup();
|
||||
}
|
||||
|
||||
int
|
||||
main(int argc, char *argv[])
|
||||
{
|
||||
int r;
|
||||
|
||||
env_setargs(argc, argv);
|
||||
|
||||
r = i2cdriver_env_parse(&bus, &address, valid_addrs);
|
||||
if (r < 0) {
|
||||
log_warn(&log, "Expecting -args 'bus=X address=0x77'\n");
|
||||
log_warn(&log, "Example -args 'bus=1 address=0x77'\n");
|
||||
return EXIT_FAILURE;
|
||||
} else if (r > 0) {
|
||||
log_warn(&log,
|
||||
"Invalid slave address for device, expecting 0x77\n");
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
sef_local_startup();
|
||||
|
||||
chardriver_task(&bmp085_tab, CHARDRIVER_SYNC);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -646,6 +646,11 @@ service sht21
|
|||
ipc SYSTEM RS DS i2c;
|
||||
};
|
||||
|
||||
service bmp085
|
||||
{
|
||||
ipc SYSTEM RS DS i2c;
|
||||
};
|
||||
|
||||
service vbox
|
||||
{
|
||||
system
|
||||
|
|
|
|||
|
|
@ -72,6 +72,9 @@ enum dev_style { STYLE_NDEV, STYLE_DEV, STYLE_DEVA, STYLE_TTY, STYLE_CTTY,
|
|||
#define SHT21B1S40_MAJOR 50 /* 50 = /dev/sht21b1s40 (sht21) */
|
||||
#define SHT21B2S40_MAJOR 51 /* 51 = /dev/sht21b2s40 (sht21) */
|
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#define SHT21B3S40_MAJOR 52 /* 52 = /dev/sht21b3s40 (sht21) */
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#define BMP085B1S77_MAJOR 53 /* 53 = /dev/bmp085b1s77 (bmp085) */
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#define BMP085B2S77_MAJOR 54 /* 54 = /dev/bmp085b2s77 (bmp085) */
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#define BMP085B3S77_MAJOR 55 /* 55 = /dev/bmp085b3s77 (bmp085) */
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||||
|
||||
|
||||
/* Minor device numbers for memory driver. */
|
||||
|
|
|
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Reference in a new issue