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author | Paer-Olof Haakansson <par-olof.hakansson@stericsson.com> | 2013-01-11 14:13:05 +0100 |
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committer | Anton Vorontsov <anton@enomsg.org> | 2013-01-16 02:44:44 +0100 |
commit | f902dadc123376b973e5f9cb216a22675a2a9181 (patch) | |
tree | 57120e6d0891005a173dc1b37d53cd19e805ad77 /drivers/power/ab8500_fg.c | |
parent | ab8500_charger: Adds support for legacy USB chargers (diff) | |
download | linux-f902dadc123376b973e5f9cb216a22675a2a9181.tar.xz linux-f902dadc123376b973e5f9cb216a22675a2a9181.zip |
ab8500_fg: Overflow in current calculation
When calculating the average current the nominator will
overflow when the charging current is high.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Henrik Sölver <henrik.solver@stericsson.com>
Reviewed-by: Par-Olof HAKANSSON <par-olof.hakansson@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Tested-by: Par-Olof HAKANSSON <par-olof.hakansson@stericsson.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>
Diffstat (limited to 'drivers/power/ab8500_fg.c')
-rw-r--r-- | drivers/power/ab8500_fg.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/drivers/power/ab8500_fg.c b/drivers/power/ab8500_fg.c index 2917def7621c..570577c32ade 100644 --- a/drivers/power/ab8500_fg.c +++ b/drivers/power/ab8500_fg.c @@ -805,12 +805,9 @@ static void ab8500_fg_acc_cur_work(struct work_struct *work) /* * Convert to unit value in mA - * Full scale input voltage is - * 66.660mV => LSB = 66.660mV/(4096*res) = 1.627mA - * Given a 250ms conversion cycle time the LSB corresponds - * to 112.9 nAh. Convert to current by dividing by the conversion + * by dividing by the conversion * time in hours (= samples / (3600 * 4)h) - * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm + * and multiply with 1000 */ di->avg_curr = (val * QLSB_NANO_AMP_HOURS_X10 * 36) / (1000 * di->bm->fg_res * (di->fg_samples / 4)); @@ -821,6 +818,8 @@ static void ab8500_fg_acc_cur_work(struct work_struct *work) queue_work(di->fg_wq, &di->fg_work); + dev_dbg(di->dev, "fg_res: %d, fg_samples: %d, gasg: %d, accu_charge: %d \n", + di->bm->fg_res, di->fg_samples, val, di->accu_charge); return; exit: dev_err(di->dev, |