From: David Lechner <david@lechnology.com>
To: Sebastian Reichel <sre@kernel.org>
Cc: David Lechner <david@lechnology.com>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] power: supply: lego_ev3_battery: fix Vce offset
Date: Fri, 20 Jul 2018 15:19:44 -0500 [thread overview]
Message-ID: <20180720201944.20503-3-david@lechnology.com> (raw)
In-Reply-To: <20180720201944.20503-1-david@lechnology.com>
This fixes the value that accounts for the Vce of a transistor in the
LEGO MINDSTORMS EV3 power supply driver. The old value (200mV) was the
max value from the data sheet. After testing, the actual value has been
found to be 50mV. By using 50mV we get a more accurate voltage
indication.
Signed-off-by: David Lechner <david@lechnology.com>
---
drivers/power/supply/lego_ev3_battery.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/power/supply/lego_ev3_battery.c b/drivers/power/supply/lego_ev3_battery.c
index 6e3b3e384172..1ae3710909b7 100644
--- a/drivers/power/supply/lego_ev3_battery.c
+++ b/drivers/power/supply/lego_ev3_battery.c
@@ -52,7 +52,7 @@ static int lego_ev3_battery_get_property(struct power_supply *psy,
return ret;
val->intval *= 2000;
- val->intval += 200000;
+ val->intval += 50000;
/* plus adjust for shunt resistor drop */
ret = iio_read_channel_processed(batt->iio_i, &val2);
--
2.17.1
next prev parent reply other threads:[~2018-07-20 20:20 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-20 20:19 [PATCH 0/2] power: supply: lego_ev3_battery improvements David Lechner
2018-07-20 20:19 ` [PATCH 1/2] power: supply: lego_ev3_battery: Don't ignore iio_read_channel_processed() return value David Lechner
2018-07-22 22:02 ` Sebastian Reichel
2018-07-20 20:19 ` David Lechner [this message]
2018-07-22 22:02 ` [PATCH 2/2] power: supply: lego_ev3_battery: fix Vce offset Sebastian Reichel
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