ad7418.c revision 164419
1/*- 2 * Copyright (c) 2006 Sam Leffler. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25#include <sys/cdefs.h> 26__FBSDID("$FreeBSD: head/sys/dev/iicbus/ad7418.c 164419 2006-11-19 23:39:54Z sam $"); 27/* 28 * Analog Devices AD7418 chip sitting on the I2C bus. 29 */ 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/kernel.h> 33#include <sys/lock.h> 34#include <sys/module.h> 35#include <sys/mutex.h> 36#include <sys/bus.h> 37#include <sys/resource.h> 38#include <sys/rman.h> 39#include <sys/sysctl.h> 40 41#include <machine/bus.h> 42#include <machine/cpu.h> 43#include <machine/cpufunc.h> 44#include <machine/frame.h> 45#include <machine/resource.h> 46#include <machine/intr.h> 47 48#include <dev/iicbus/iiconf.h> 49 50#include "iicbus_if.h" 51 52#define IIC_M_WR 0 /* write operation */ 53 54#define AD7418_ADDR 0x50 /* slave address */ 55 56#define AD7418_TEMP 0 /* Temperature Value (r/o) */ 57#define AD7418_CONF 1 /* Config Register (r/w) */ 58#define AD7418_CONF_SHUTDOWN 0x01 59#define AD7418_CONF_CHAN 0xe0 /* channel select mask */ 60#define AD7418_CHAN_TEMP 0x00 /* temperature channel */ 61#define AD7418_CHAN_VOLT 0x80 /* voltage channel */ 62#define AD7418_THYST 2 /* Thyst Setpoint (r/o) */ 63#define AD7418_TOTI 3 /* Toti Setpoint */ 64#define AD7418_VOLT 4 /* ADC aka Voltage (r/o) */ 65#define AD7418_CONF2 5 /* Config2 Register (r/w) */ 66 67struct ad7418_softc { 68 device_t sc_dev; 69 struct mtx sc_mtx; 70 int sc_curchan; /* current channel */ 71 int sc_curtemp; 72 int sc_curvolt; 73 int sc_lastupdate; /* in ticks */ 74}; 75 76static void ad7418_update(struct ad7418_softc *); 77static int ad7418_read_1(device_t dev, int reg); 78static int ad7418_write_1(device_t dev, int reg, int v); 79 80static int 81ad7418_probe(device_t dev) 82{ 83 /* XXX really probe? */ 84 device_set_desc(dev, "Analog Devices AD7418 ADC"); 85 return (0); 86} 87 88static int 89ad7418_sysctl_temp(SYSCTL_HANDLER_ARGS) 90{ 91 struct ad7418_softc *sc = arg1; 92 int temp; 93 94 ad7418_update(sc); 95 temp = (sc->sc_curtemp / 64) * 25; 96 return sysctl_handle_int(oidp, &temp, 0, req); 97} 98 99static int 100ad7418_sysctl_voltage(SYSCTL_HANDLER_ARGS) 101{ 102 struct ad7418_softc *sc = arg1; 103 int volt; 104 105 ad7418_update(sc); 106 volt = (sc->sc_curvolt >> 6) * 564 / 10; 107 return sysctl_handle_int(oidp, &volt, 0, req); 108} 109 110static int 111ad7418_attach(device_t dev) 112{ 113 struct ad7418_softc *sc = device_get_softc(dev); 114 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(dev); 115 struct sysctl_oid *tree = device_get_sysctl_tree(dev); 116 int conf; 117 118 sc->sc_dev = dev; 119 mtx_init(&sc->sc_mtx, "ad7418", "ad7418", MTX_DEF); 120 121 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 122 "temp", CTLTYPE_INT | CTLFLAG_RD, sc, 0, 123 ad7418_sysctl_temp, "I", "operating temperature"); 124 SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, 125 "volt", CTLTYPE_INT | CTLFLAG_RD, sc, 0, 126 ad7418_sysctl_voltage, "I", "input voltage"); 127 128 /* enable chip if configured in shutdown mode */ 129 conf = ad7418_read_1(dev, AD7418_CONF); 130 if (conf >= 0 && (conf & AD7418_CONF_SHUTDOWN)) 131 ad7418_write_1(dev, AD7418_CONF, conf &~ AD7418_CONF_SHUTDOWN); 132 133 return (0); 134} 135 136static int 137ad7418_read_1(device_t dev, int reg) 138{ 139 uint8_t addr = reg; 140 uint8_t data[1]; 141 struct iic_msg msgs[2] = { 142 { AD7418_ADDR, IIC_M_WR, 1, &addr }, 143 { AD7418_ADDR, IIC_M_RD, 1, data }, 144 }; 145 return iicbus_transfer(dev, msgs, 2) != 0 ? -1 : data[0]; 146} 147 148static int 149ad7418_write_1(device_t dev, int reg, int v) 150{ 151 /* NB: register pointer precedes actual data */ 152 uint8_t data[2]; 153 struct iic_msg msgs[1] = { 154 { AD7418_ADDR, IIC_M_WR, 2, data }, 155 }; 156 data[0] = reg; 157 data[1] = v & 0xff; 158 return iicbus_transfer(dev, msgs, 1); 159} 160 161static void 162ad7418_set_channel(struct ad7418_softc *sc, int chan) 163{ 164 if (sc->sc_curchan == chan) 165 return; 166 ad7418_write_1(sc->sc_dev, AD7418_CONF, 167 (ad7418_read_1(sc->sc_dev, AD7418_CONF) &~ AD7418_CONF_CHAN)|chan); 168 sc->sc_curchan = chan; 169#if 0 170 /* 171 * NB: Linux driver delays here but chip data sheet 172 * says nothing and things appear to work fine w/o 173 * a delay on channel change. If this is enabled 174 * be sure to account for losing the mutex below 175 * in ad7418_update. 176 */ 177 mtx_assert(&sc->sc_mtx, MA_OWNED); 178 /* let channel change settle, 1 tick should be 'nuf (need ~1ms) */ 179 msleep(sc, &sc->sc_mtx, 0, "ad7418", 1); 180#endif 181} 182 183static int 184ad7418_read_2(device_t dev, int reg) 185{ 186 uint8_t addr = reg; 187 uint8_t data[2]; 188 struct iic_msg msgs[2] = { 189 { AD7418_ADDR, IIC_M_WR, 1, &addr }, 190 { AD7418_ADDR, IIC_M_RD, 2, data }, 191 }; 192 /* NB: D15..D8 precede D7..D0 per data sheet (Fig 12) */ 193 return iicbus_transfer(dev, msgs, 2) != 0 ? 194 -1 : ((data[0] << 8) | data[1]); 195} 196 197static void 198ad7418_update(struct ad7418_softc *sc) 199{ 200 int v; 201 202 mtx_lock(&sc->sc_mtx); 203 /* NB: no point in updating any faster than the chip */ 204 if (ticks - sc->sc_lastupdate > hz) { 205 ad7418_set_channel(sc, AD7418_CHAN_TEMP); 206 v = ad7418_read_2(sc->sc_dev, AD7418_TEMP); 207 if (v >= 0) 208 sc->sc_curtemp = v; 209 ad7418_set_channel(sc, AD7418_CHAN_VOLT); 210 v = ad7418_read_2(sc->sc_dev, AD7418_VOLT); 211 if (v >= 0) 212 sc->sc_curvolt = v; 213 sc->sc_lastupdate = ticks; 214 } 215 mtx_unlock(&sc->sc_mtx); 216} 217 218static device_method_t ad7418_methods[] = { 219 DEVMETHOD(device_probe, ad7418_probe), 220 DEVMETHOD(device_attach, ad7418_attach), 221 222 {0, 0}, 223}; 224 225static driver_t ad7418_driver = { 226 "ad7418", 227 ad7418_methods, 228 sizeof(struct ad7418_softc), 229}; 230static devclass_t ad7418_devclass; 231 232DRIVER_MODULE(ad7418, iicbus, ad7418_driver, ad7418_devclass, 0, 0); 233MODULE_VERSION(ad7418, 1); 234MODULE_DEPEND(ad7418, iicbus, 1, 1, 1); 235