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author | sam <sam@FreeBSD.org> | 2006-11-19 23:39:54 +0000 |
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committer | sam <sam@FreeBSD.org> | 2006-11-19 23:39:54 +0000 |
commit | 84fa826955b84d85a1f7eea3033ce2c92c9f7257 (patch) | |
tree | 8d4dc5048182e8379c12d7685414dbdc1d2d4089 /sys/dev/iicbus | |
parent | d93a445ea97edb49f965bcfb008df046756e4d69 (diff) | |
download | FreeBSD-src-84fa826955b84d85a1f7eea3033ce2c92c9f7257.zip FreeBSD-src-84fa826955b84d85a1f7eea3033ce2c92c9f7257.tar.gz |
i2c driver for Analog Devices AD7418
MFC after: 1 month
Diffstat (limited to 'sys/dev/iicbus')
-rw-r--r-- | sys/dev/iicbus/ad7418.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/sys/dev/iicbus/ad7418.c b/sys/dev/iicbus/ad7418.c new file mode 100644 index 0000000..ec68fc1 --- /dev/null +++ b/sys/dev/iicbus/ad7418.c @@ -0,0 +1,234 @@ +/*- + * Copyright (c) 2006 Sam Leffler. All rights reserved. + * + * 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); +/* + * Analog Devices AD7418 chip sitting on the I2C bus. + */ +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/module.h> +#include <sys/mutex.h> +#include <sys/bus.h> +#include <sys/resource.h> +#include <sys/rman.h> +#include <sys/sysctl.h> + +#include <machine/bus.h> +#include <machine/cpu.h> +#include <machine/cpufunc.h> +#include <machine/frame.h> +#include <machine/resource.h> +#include <machine/intr.h> + +#include <dev/iicbus/iiconf.h> + +#include "iicbus_if.h" + +#define IIC_M_WR 0 /* write operation */ + +#define AD7418_ADDR 0x50 /* slave address */ + +#define AD7418_TEMP 0 /* Temperature Value (r/o) */ +#define AD7418_CONF 1 /* Config Register (r/w) */ +#define AD7418_CONF_SHUTDOWN 0x01 +#define AD7418_CONF_CHAN 0xe0 /* channel select mask */ +#define AD7418_CHAN_TEMP 0x00 /* temperature channel */ +#define AD7418_CHAN_VOLT 0x80 /* voltage channel */ +#define AD7418_THYST 2 /* Thyst Setpoint (r/o) */ +#define AD7418_TOTI 3 /* Toti Setpoint */ +#define AD7418_VOLT 4 /* ADC aka Voltage (r/o) */ +#define AD7418_CONF2 5 /* Config2 Register (r/w) */ + +struct ad7418_softc { + device_t sc_dev; + struct mtx sc_mtx; + int sc_curchan; /* current channel */ + int sc_curtemp; + int sc_curvolt; + int sc_lastupdate; /* in ticks */ +}; + +static void ad7418_update(struct ad7418_softc *); +static int ad7418_read_1(device_t dev, int reg); +static int ad7418_write_1(device_t dev, int reg, int v); + +static int +ad7418_probe(device_t dev) +{ + /* XXX really probe? */ + device_set_desc(dev, "Analog Devices AD7418 ADC"); + return (0); +} + +static int +ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS) +{ + struct ad7418_softc *sc = arg1; + int temp; + + ad7418_update(sc); + temp = (sc->sc_curtemp / 64) * 25; + return sysctl_handle_int(oidp, &temp, 0, req); +} + +static int +ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS) +{ + struct ad7418_softc *sc = arg1; + int volt; + + ad7418_update(sc); + volt = (sc->sc_curvolt >> 6) * 564 / 10; + return sysctl_handle_int(oidp, &volt, 0, req); +} + +static int +ad7418_attach(device_t dev) +{ + struct ad7418_softc *sc = device_get_softc(dev); + struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev); + struct sysctl_oid *tree = device_get_sysctl_tree(dev); + int conf; + + sc->sc_dev = dev; + mtx_init(&sc->sc_mtx, "ad7418", "ad7418", MTX_DEF); + + SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, + "temp", CTLTYPE_INT | CTLFLAG_RD, sc, 0, + ad7418_sysctl_temp, "I", "operating temperature"); + SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, + "volt", CTLTYPE_INT | CTLFLAG_RD, sc, 0, + ad7418_sysctl_voltage, "I", "input voltage"); + + /* enable chip if configured in shutdown mode */ + conf = ad7418_read_1(dev, AD7418_CONF); + if (conf >= 0 && (conf & AD7418_CONF_SHUTDOWN)) + ad7418_write_1(dev, AD7418_CONF, conf &~ AD7418_CONF_SHUTDOWN); + + return (0); +} + +static int +ad7418_read_1(device_t dev, int reg) +{ + uint8_t addr = reg; + uint8_t data[1]; + struct iic_msg msgs[2] = { + { AD7418_ADDR, IIC_M_WR, 1, &addr }, + { AD7418_ADDR, IIC_M_RD, 1, data }, + }; + return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0]; +} + +static int +ad7418_write_1(device_t dev, int reg, int v) +{ + /* NB: register pointer precedes actual data */ + uint8_t data[2]; + struct iic_msg msgs[1] = { + { AD7418_ADDR, IIC_M_WR, 2, data }, + }; + data[0] = reg; + data[1] = v & 0xff; + return iicbus_transfer(dev, msgs, 1); +} + +static void +ad7418_set_channel(struct ad7418_softc *sc, int chan) +{ + if (sc->sc_curchan == chan) + return; + ad7418_write_1(sc->sc_dev, AD7418_CONF, + (ad7418_read_1(sc->sc_dev, AD7418_CONF) &~ AD7418_CONF_CHAN)|chan); + sc->sc_curchan = chan; +#if 0 + /* + * NB: Linux driver delays here but chip data sheet + * says nothing and things appear to work fine w/o + * a delay on channel change. If this is enabled + * be sure to account for losing the mutex below + * in ad7418_update. + */ + mtx_assert(&sc->sc_mtx, MA_OWNED); + /* let channel change settle, 1 tick should be 'nuf (need ~1ms) */ + msleep(sc, &sc->sc_mtx, 0, "ad7418", 1); +#endif +} + +static int +ad7418_read_2(device_t dev, int reg) +{ + uint8_t addr = reg; + uint8_t data[2]; + struct iic_msg msgs[2] = { + { AD7418_ADDR, IIC_M_WR, 1, &addr }, + { AD7418_ADDR, IIC_M_RD, 2, data }, + }; + /* NB: D15..D8 precede D7..D0 per data sheet (Fig 12) */ + return iicbus_transfer(dev, msgs, 2) != 0 ? + -1 : ((data[0] << 8) | data[1]); +} + +static void +ad7418_update(struct ad7418_softc *sc) +{ + int v; + + mtx_lock(&sc->sc_mtx); + /* NB: no point in updating any faster than the chip */ + if (ticks - sc->sc_lastupdate > hz) { + ad7418_set_channel(sc, AD7418_CHAN_TEMP); + v = ad7418_read_2(sc->sc_dev, AD7418_TEMP); + if (v >= 0) + sc->sc_curtemp = v; + ad7418_set_channel(sc, AD7418_CHAN_VOLT); + v = ad7418_read_2(sc->sc_dev, AD7418_VOLT); + if (v >= 0) + sc->sc_curvolt = v; + sc->sc_lastupdate = ticks; + } + mtx_unlock(&sc->sc_mtx); +} + +static device_method_t ad7418_methods[] = { + DEVMETHOD(device_probe, ad7418_probe), + DEVMETHOD(device_attach, ad7418_attach), + + {0, 0}, +}; + +static driver_t ad7418_driver = { + "ad7418", + ad7418_methods, + sizeof(struct ad7418_softc), +}; +static devclass_t ad7418_devclass; + +DRIVER_MODULE(ad7418, iicbus, ad7418_driver, ad7418_devclass, 0, 0); +MODULE_VERSION(ad7418, 1); +MODULE_DEPEND(ad7418, iicbus, 1, 1, 1); |