[PATCH 39/40] ab8500-fg: Change current calculation

From: Lee Jones
Date: Fri Feb 15 2013 - 07:47:24 EST


From: lme00437 <benoit.gauthier-nonst@xxxxxxxxxxxxxx>

This patch updates the gas gauge constant for electric current
calculation according to hardware specification.

Signed-off-by: Benoit GAUTHIER <benoit.gauthier-xsig@xxxxxxxxxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
Reviewed-by: Marcus COOPER <marcus.xm.cooper@xxxxxxxxxxxxxx>
Reviewed-by: Philippe LANGLAIS <philippe.langlais@xxxxxxxxxxxxxx>
Tested-by: Benoit GAUTHIER <benoit.gauthier-xsig@xxxxxxxxxxxxxx>
---
drivers/power/ab8500_fg.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/power/ab8500_fg.c b/drivers/power/ab8500_fg.c
index 7de5333..4968061 100644
--- a/drivers/power/ab8500_fg.c
+++ b/drivers/power/ab8500_fg.c
@@ -36,7 +36,7 @@

#define MILLI_TO_MICRO 1000
#define FG_LSB_IN_MA 1627
-#define QLSB_NANO_AMP_HOURS_X10 1129
+#define QLSB_NANO_AMP_HOURS_X10 1071
#define INS_CURR_TIMEOUT (3 * HZ)

#define SEC_TO_SAMPLE(S) (S * 4)
@@ -672,11 +672,11 @@ int ab8500_fg_inst_curr_finalize(struct ab8500_fg *di, int *res)
/*
* Convert to unit value in mA
* Full scale input voltage is
- * 66.660mV => LSB = 66.660mV/(4096*res) = 1.627mA
+ * 63.160mV => LSB = 63.160mV/(4096*res) = 1.542mA
* Given a 250ms conversion cycle time the LSB corresponds
- * to 112.9 nAh. Convert to current by dividing by the conversion
+ * to 107.1 nAh. Convert to current by dividing by the conversion
* time in hours (250ms = 1 / (3600 * 4)h)
- * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm
+ * 107.1nAh assumes 10mOhm, but fg_res is in 0.1mOhm
*/
val = (val * QLSB_NANO_AMP_HOURS_X10 * 36 * 4) /
(1000 * di->bm->fg_res);
--
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/