handle all 3 types of chips correctly. go into continuous mode, and

start the chips right (two kinds of start sequences).  then get the
temperature readings correctly, including negative temperatures.
done with grange.
pity the poor russian with only the lowest of the low end i2c chips

1 files changed, 41 insertions, 2 deletions

diff --git a/sys/dev/i2c/ds1631.c b/sys/dev/i2c/ds1631.c
index 703e063a8c7..13bcc30d9e8 100644
--- a/sys/dev/i2c/ds1631.c
+++ b/sys/dev/i2c/ds1631.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ds1631.c,v 1.3 2006/01/13 00:13:01 deraadt Exp $	*/
+/*	$OpenBSD: ds1631.c,v 1.4 2006/01/13 21:41:40 deraadt Exp $	*/
 
 /*
  * Copyright (c) 2005 Theo de Raadt
@@ -24,7 +24,12 @@
 #include <dev/i2c/i2cvar.h>
 
 /* Maxim ds 1631 registers */
+#define DS1631_START		0x51
+#define DS1624_START		0xee
 #define DS1631_TEMP		0xaa
+#define DS1631_CONTROL		0xac
+#define  DS1631_CONTROL_DONE	0x80
+#define  DS1631_CONTROL_1SHOT	0x01
 
 /* Sensors */
 #define MAXDS_TEMP		0
@@ -67,11 +72,45 @@ maxds_attach(struct device *parent, struct device *self, void *aux)
 {
 	struct maxds_softc *sc = (struct maxds_softc *)self;
 	struct i2c_attach_args *ia = aux;
+	u_int8_t cmd, data;
 	int i;
 
+	printf(": %s", ia->ia_name);
+
 	sc->sc_tag = ia->ia_tag;
 	sc->sc_addr = ia->ia_addr;
 
+	iic_acquire_bus(sc->sc_tag, 0);
+
+	cmd = DS1631_CONTROL;
+	if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
+	    sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0) == 0) {
+		if (data & DS1631_CONTROL_1SHOT) {
+			/*
+			 * 1-Shot mode would require us to write every refresh
+			 * which is stupid.  Put us into continuous mode.
+			 */
+			data &= ~DS1631_CONTROL_1SHOT;
+
+			(void) iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
+			    sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0);
+			//delay(10 * 1000);
+			printf(", continuous");
+			goto dostart;
+		}
+		if (data & DS1631_CONTROL_DONE) {
+dostart:
+			cmd = DS1631_START;
+			if (strcmp(ia->ia_name, "ds1624") == 0)
+				cmd = DS1624_START;
+			(void) iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
+			    sc->sc_addr, &cmd, sizeof cmd, NULL, 0, 0);
+			printf(", starting");
+		}
+	}
+
+	iic_release_bus(sc->sc_tag, 0);
+
 	/* Initialize sensor data. */
 	for (i = 0; i < MAXDS_NUM_SENSORS; i++)
 		strlcpy(sc->sc_sensor[i].device, sc->sc_dev.dv_xname,
@@ -104,7 +143,7 @@ maxds_refresh(void *arg)
 	if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
 	    sc->sc_addr, &cmd, sizeof cmd, &data, sizeof data, 0) == 0)
 		sc->sc_sensor[MAXDS_TEMP].value = 273150000 +
-		    1000000 * data[1] + 1000000 * data[0] / 256;
+		    ((int)((u_int16_t)data[0] << 8 | data[1])) / 8 * 31250;
 
 	iic_release_bus(sc->sc_tag, 0);
 }