[src/trunk]: src/sys/dev/i2c Support setting the temperature threshold for th...

[macallan <macallan%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7b67118b36e6
branches:  trunk
changeset: 771099:7b67118b36e6
user:      macallan <macallan%NetBSD.org@localhost>
date:      Wed Nov 09 05:47:54 2011 +0000

description:
Support setting the temperature threshold for the LM75's alarm/interrupt
output. Some hardware ( I'm looking at you, Gdium ) abuses it to control
a fan.

diffstat:

 sys/dev/i2c/lm75.c |  102 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 99 insertions(+), 3 deletions(-)

diffs (171 lines):

diff -r 64e71e8b8df3 -r 7b67118b36e6 sys/dev/i2c/lm75.c
--- a/sys/dev/i2c/lm75.c        Wed Nov 09 00:51:00 2011 +0000
+++ b/sys/dev/i2c/lm75.c        Wed Nov 09 05:47:54 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: lm75.c,v 1.22 2011/06/20 20:16:19 pgoyette Exp $       */
+/*     $NetBSD: lm75.c,v 1.23 2011/11/09 05:47:54 macallan Exp $       */
 
 /*
  * Copyright (c) 2003 Wasabi Systems, Inc.
@@ -36,12 +36,13 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: lm75.c,v 1.22 2011/06/20 20:16:19 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: lm75.c,v 1.23 2011/11/09 05:47:54 macallan Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/device.h>
 #include <sys/kernel.h>
+#include <sys/sysctl.h>
 
 #include <dev/sysmon/sysmonvar.h>
 
@@ -49,11 +50,13 @@
 #include <dev/i2c/lm75reg.h>
 
 struct lmtemp_softc {
+       device_t sc_dev;
        i2c_tag_t sc_tag;
        int sc_address;
 
        struct sysmon_envsys *sc_sme;
        envsys_data_t sc_sensor;
+       int sc_tmax;
 
        uint32_t (*sc_lmtemp_decode)(const uint8_t *);
 };
@@ -67,10 +70,13 @@
 static void    lmtemp_refresh(struct sysmon_envsys *, envsys_data_t *);
 
 static int     lmtemp_config_write(struct lmtemp_softc *, uint8_t);
+static int     lmtemp_temp_write(struct lmtemp_softc *, int, uint16_t);
 static uint32_t lmtemp_decode_lm75(const uint8_t *);
 static uint32_t lmtemp_decode_ds75(const uint8_t *);
 static uint32_t lmtemp_decode_lm77(const uint8_t *);
 
+static void    lmtemp_setup_sysctl(struct lmtemp_softc *);
+static int     sysctl_lm75_temp(SYSCTLFN_ARGS);
 
 static const char * lmtemp_compats[] = {
        "i2c-lm75",
@@ -143,6 +149,7 @@
        struct i2c_attach_args *ia = aux;
        int i;
 
+       sc->sc_dev = self;
        if (ia->ia_name == NULL) {
                for (i = 0; lmtemptbl[i].lmtemp_type != -1 ; i++)
                        if (lmtemptbl[i].lmtemp_type ==
@@ -165,9 +172,17 @@
                        lmtemptbl[i].lmtemp_name);
        }
 
+       /*
+        * according to the LM75 data sheet 80C is the default, so leave it
+        * there to avoid unexpected behaviour
+        */
+       sc->sc_tmax = 80;
+       if (i == lmtemp_lm75)
+               lmtemp_setup_sysctl(sc);
+
        /* Set the configuration of the LM75 to defaults. */
        iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
-       if (lmtemp_config_write(sc, 0) != 0) {
+       if (lmtemp_config_write(sc, LM75_CONFIG_FAULT_QUEUE_4) != 0) {
                aprint_error_dev(self, "unable to write config register\n");
                iic_release_bus(sc->sc_tag, I2C_F_POLL);
                return;
@@ -212,6 +227,19 @@
 }
 
 static int
+lmtemp_temp_write(struct lmtemp_softc *sc, int reg, uint16_t val)
+{
+       uint8_t cmdbuf[3];
+
+       cmdbuf[0] = reg;
+       cmdbuf[1] = (val >> 1) & 0xff;
+       cmdbuf[2] = (val & 1) << 7;
+
+       return iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
+           sc->sc_address, cmdbuf, 1, &cmdbuf[1], 2, I2C_F_POLL);
+}
+
+static int
 lmtemp_temp_read(struct lmtemp_softc *sc, uint8_t which, uint32_t *valp)
 {
        int error;
@@ -316,3 +344,71 @@
        return val;
 }
 
+static void
+lmtemp_setup_sysctl(struct lmtemp_softc *sc)
+{
+       const struct sysctlnode *me = NULL, *node = NULL;
+
+       iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+       lmtemp_temp_write(sc, LM75_REG_THYST_SET_POINT, (sc->sc_tmax - 5) * 2);
+       lmtemp_temp_write(sc, LM75_REG_TOS_SET_POINT, sc->sc_tmax * 2);
+       iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+       sysctl_createv(NULL, 0, NULL, &me,
+           CTLFLAG_READWRITE,
+           CTLTYPE_NODE, device_xname(sc->sc_dev), NULL,
+           NULL, 0, NULL, 0,
+           CTL_MACHDEP, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(NULL, 0, NULL, &node,
+           CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
+           CTLTYPE_INT, "temp", "Threshold temperature",
+           sysctl_lm75_temp, 1, sc, 0,
+           CTL_MACHDEP, me->sysctl_num, CTL_CREATE, CTL_EOL);
+}
+
+static int
+sysctl_lm75_temp(SYSCTLFN_ARGS)
+{
+       struct sysctlnode node = *rnode;
+       struct lmtemp_softc *sc = node.sysctl_data;
+       int temp;
+
+       if (newp) {
+
+               /* we're asked to write */      
+               node.sysctl_data = &sc->sc_tmax;
+               if (sysctl_lookup(SYSCTLFN_CALL(&node)) == 0) {
+
+                       temp = *(int *)node.sysctl_data;
+                       sc->sc_tmax = temp;
+                       iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+                       lmtemp_temp_write(sc, LM75_REG_THYST_SET_POINT,
+                           (sc->sc_tmax - 5) * 2);
+                       lmtemp_temp_write(sc, LM75_REG_TOS_SET_POINT,
+                           sc->sc_tmax * 2);
+                       iic_release_bus(sc->sc_tag, I2C_F_POLL);
+                       return 0;
+               }
+               return EINVAL;
+       } else {
+
+               node.sysctl_data = &sc->sc_tmax;
+               node.sysctl_size = 4;
+               return (sysctl_lookup(SYSCTLFN_CALL(&node)));
+       }
+
+       return 0;
+}
+
+SYSCTL_SETUP(sysctl_lmtemp_setup, "sysctl lmtemp subtree setup")
+{
+
+       sysctl_createv(NULL, 0, NULL, NULL,
+                      CTLFLAG_PERMANENT,
+                      CTLTYPE_NODE, "machdep", NULL,
+                      NULL, 0, NULL, 0,
+                      CTL_MACHDEP, CTL_EOL);
+}
+
+