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axp20x.c revision 1.1 
      1 /* $NetBSD: axp20x.c,v 1.1 2014/09/09 22:47:33 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2014 Jared D. McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: axp20x.c,v 1.1 2014/09/09 22:47:33 jmcneill Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/systm.h>
     34 #include <sys/device.h>
     35 #include <sys/conf.h>
     36 #include <sys/bus.h>
     37 #include <sys/kmem.h>
     38 
     39 #include <dev/i2c/i2cvar.h>
     40 
     41 #include <dev/sysmon/sysmonvar.h>
     42 
     43 #define AXP_TEMP_MON_REG	0x5e	/* 2 bytes */
     44 
     45 struct axp20x_softc {
     46 	device_t	sc_dev;
     47 	i2c_tag_t	sc_i2c;
     48 	i2c_addr_t	sc_addr;
     49 
     50 	struct sysmon_envsys *sc_sme;
     51 	envsys_data_t	sc_sensor_temp;
     52 };
     53 
     54 static int	axp20x_match(device_t, cfdata_t, void *);
     55 static void	axp20x_attach(device_t, device_t, void *);
     56 
     57 static void	axp20x_sensors_refresh(struct sysmon_envsys *, envsys_data_t *);
     58 static int	axp20x_read(struct axp20x_softc *, uint8_t, uint8_t *, size_t);
     59 
     60 CFATTACH_DECL_NEW(axp20x, sizeof(struct axp20x_softc),
     61     axp20x_match, axp20x_attach, NULL, NULL);
     62 
     63 static int
     64 axp20x_match(device_t parent, cfdata_t match, void *aux)
     65 {
     66 	return 1;
     67 }
     68 
     69 static void
     70 axp20x_attach(device_t parent, device_t self, void *aux)
     71 {
     72 	struct axp20x_softc *sc = device_private(self);
     73 	struct i2c_attach_args *ia = aux;
     74 
     75 	sc->sc_dev = self;
     76 	sc->sc_i2c = ia->ia_tag;
     77 	sc->sc_addr = ia->ia_addr;
     78 
     79 	aprint_naive("\n");
     80 	aprint_normal("\n");
     81 
     82 	sc->sc_sme = sysmon_envsys_create();
     83 	sc->sc_sme->sme_name = device_xname(self);
     84 	sc->sc_sme->sme_cookie = sc;
     85 	sc->sc_sme->sme_refresh = axp20x_sensors_refresh;
     86 
     87 	sc->sc_sensor_temp.units = ENVSYS_STEMP;
     88 	sc->sc_sensor_temp.state = ENVSYS_SINVALID;
     89 	sc->sc_sensor_temp.flags = ENVSYS_FHAS_ENTROPY;
     90 	snprintf(sc->sc_sensor_temp.desc, sizeof(sc->sc_sensor_temp),
     91 	    "internal temperature");
     92 	sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor_temp);
     93 
     94 	sysmon_envsys_register(sc->sc_sme);
     95 }
     96 
     97 static void
     98 axp20x_sensors_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
     99 {
    100 	struct axp20x_softc *sc = sme->sme_cookie;
    101 	uint8_t buf[2];
    102 	int error;
    103 
    104 	iic_acquire_bus(sc->sc_i2c, 0);
    105 	error = axp20x_read(sc, AXP_TEMP_MON_REG, buf, sizeof(buf));
    106 	iic_release_bus(sc->sc_i2c, 0);
    107 
    108 	if (error) {
    109 		edata->state = ENVSYS_SINVALID;
    110 	} else {
    111 		/* between -144.7C and 264.8C, step +0.1C */
    112 		edata->value_cur = (((buf[0] << 4) | (buf[1] & 0xf)) - 1447)
    113 				   * 100000 + 273150000;
    114 		edata->state = ENVSYS_SVALID;
    115 	}
    116 }
    117 
    118 static int
    119 axp20x_read(struct axp20x_softc *sc, uint8_t reg, uint8_t *val, size_t len)
    120 {
    121 	return iic_smbus_block_read(sc->sc_i2c, sc->sc_addr,
    122 	    reg, val, len, 0);
    123 }
    124