commit b16918a5fd87983d421a7e2241a1314e877c4ea2
author Martyn Welch <martyn.welch@collabora.co.uk> Thu Oct 19 16:51:44 2017 +0100
committer Guenter Roeck <linux@roeck-us.net> Sat Oct 21 09:03:29 2017 -0700
tree dedd75860f16877654114ed7cf3784b1514ce1bd
parent 8a5776a5f49812d29fe4b2d0a2d71675c3facf3f

hwmon: (da9052) Increase sample rate when using TSI

The TSI channel, which is usually used for touchscreen support, but can
be used as 4 general purpose ADCs. When used as a touchscreen interface
the touchscreen driver switches the device into 1ms sampling mode (rather
than the default 10ms economy mode) as recommended by the manufacturer.
When using the TSI channels as a general purpose ADC we are currently not
doing this and testing suggests that this can result in ADC timeouts:

[ 5827.198289] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5827.728293] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5993.808335] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5994.328441] da9052 spi2.0: timeout waiting for ADC conversion interrupt
[ 5994.848291] da9052 spi2.0: timeout waiting for ADC conversion interrupt

Switching to the 1ms timing resolves this issue.

Fixes: 4f16cab19a3d5 ("hwmon: da9052: Add support for TSI channel")
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>