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authorPeter Tyser <ptyser@xes-inc.com>2010-09-29 13:46:17 -0500
committerWolfgang Denk <wd@denx.de>2010-10-06 23:01:19 +0200
commitc3e5fa0b53c0a83c87298e486ae7ec663d44566f (patch)
tree0350100f710d73547119a3ccc14800387a73eb63 /drivers/hwmon
parentfc5fc76bdad14425e3743e1494c9e444570df1be (diff)
downloadu-boot-linaro-stable-c3e5fa0b53c0a83c87298e486ae7ec663d44566f.tar.gz
ds1621: Poll for register write completion
Poll the ds1621 NV Memory Busy bit instead of waiting a static amount of time for register writes. Also add config retister bit defines. Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/ds1621.c26
1 files changed, 21 insertions, 5 deletions
diff --git a/drivers/hwmon/ds1621.c b/drivers/hwmon/ds1621.c
index d15a082df..ec1893e1d 100644
--- a/drivers/hwmon/ds1621.c
+++ b/drivers/hwmon/ds1621.c
@@ -22,7 +22,7 @@
*/
/*
- * Dallas Semiconductor's DS1621 Digital Thermometer and Thermostat.
+ * Dallas Semiconductor's DS1621/1631 Digital Thermometer and Thermostat.
*/
#include <common.h>
@@ -42,6 +42,19 @@
#define DTT_TEMP_LOW 0xA2
#define DTT_CONFIG 0xAC
+/*
+ * Config register bits
+ */
+#define DTT_CONFIG_1SHOT 0x01
+#define DTT_CONFIG_POLARITY 0x02
+#define DTT_CONFIG_R0 0x04 /* ds1631 only */
+#define DTT_CONFIG_R1 0x08 /* ds1631 only */
+#define DTT_CONFIG_NVB 0x10
+#define DTT_CONFIG_TLF 0x20
+#define DTT_CONFIG_THF 0x40
+#define DTT_CONFIG_DONE 0x80
+
+
int dtt_read(int sensor, int reg)
{
int dlen;
@@ -114,6 +127,12 @@ int dtt_write(int sensor, int reg, int val)
if (i2c_write(sensor, reg, 1, data, dlen) != 0)
return 1;
+ /*
+ * Poll NV memory busy bit in case write was to register stored in EEPROM
+ */
+ while(i2c_reg_read(sensor, DTT_CONFIG) & DTT_CONFIG_NVB)
+ ;
+
return 0;
} /* dtt_write() */
@@ -128,7 +147,6 @@ static int _dtt_init(int sensor)
val = ((CONFIG_SYS_DTT_MAX_TEMP * 2) << 7) & 0xff80;
if (dtt_write(sensor, DTT_TEMP_HIGH, val) != 0)
return 1;
- udelay(50000); /* Max 50ms */
/*
* Setup Low Temp - hysteresis.
@@ -136,7 +154,6 @@ static int _dtt_init(int sensor)
val = (((CONFIG_SYS_DTT_MAX_TEMP - CONFIG_SYS_DTT_HYSTERESIS) * 2) << 7) & 0xff80;
if (dtt_write(sensor, DTT_TEMP_LOW, val) != 0)
return 1;
- udelay(50000); /* Max 50ms */
/*
* Setup configuraton register
@@ -149,7 +166,6 @@ static int _dtt_init(int sensor)
val = 0x9;
if (dtt_write(sensor, DTT_CONFIG, val) != 0)
return 1;
- udelay(50000); /* Max 50ms */
return 0;
} /* _dtt_init() */
@@ -181,7 +197,7 @@ int dtt_get_temp(int sensor)
dtt_write(sensor, DTT_WRITE_START_CONV, 0);
for (i = 0; i <= 10; i++) {
udelay(100000);
- if (dtt_read(sensor, DTT_CONFIG) & 0x80)
+ if (dtt_read(sensor, DTT_CONFIG) & DTT_CONFIG_DONE)
break;
}