ds2760_battery: handle full_active_uAh == 0 case correctly

In systems where the battery monitor is not part of the battery pack and
is hence not bootstrapped with sane values, the full_active_uAh is
likely to be zero.

Handle that case by defaulting to the rated_capacity information which
can be passed to the driver using the new module parameter.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
Acked-by: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c
index ed0ea5e275c5414e73a60f7ab5a0e1cec2c9edb9..2d0e5edb47425dcc1bea8c368373cea03b518aa8 100644 (file)
--- a/drivers/power/ds2760_battery.c
+++ b/drivers/power/ds2760_battery.c
@@ -172,8 +172,13 @@ static int ds2760_battery_read_status(struct ds2760_device_info *di)
        di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
                              di->raw[DS2760_ACTIVE_FULL + 1];
 
-       scale[0] = di->raw[DS2760_ACTIVE_FULL] << 8 |
-                  di->raw[DS2760_ACTIVE_FULL + 1];
+       /* If the full_active_uAh value is not given, fall back to the rated
+        * capacity. This is likely to happen when chips are not part of the
+        * battery pack and is therefore not bootstrapped. */
+       if (di->full_active_uAh == 0)
+               di->full_active_uAh = di->rated_capacity / 1000L;
+
+       scale[0] = di->full_active_uAh;
        for (i = 1; i < 5; i++)
                scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 2 + i];