Re: [PATCH v2] hwmon: Add LTC2990 sensor driver

From: Mike Looijmans
Date: Wed Jan 13 2016 - 09:05:47 EST


ïOn 13-01-16 14:57, Guenter Roeck wrote:
On 01/13/2016 05:51 AM, Mike Looijmans wrote:
On 13-01-16 14:24, Guenter Roeck wrote:
On 01/13/2016 03:05 AM, Mike Looijmans wrote:
This adds support for the Linear Technology LTC2990 I2C System Monitor.
The LTC2990 supports a combination of voltage, current and temperature
monitoring. This driver currently only supports reading two currents
by measuring two differential voltages across series resistors, in
addition to the Vcc supply voltage and internal temperature.

This is sufficient to support the Topic Miami SOM which uses this chip
to monitor the currents flowing into the FPGA and the CPU parts.

Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>

Mike,

That looks much better. Can you send me the output of i2cdump for the chip ?
That would help me writing module test code for it.

I'm kinda interested into how that would work.

https://github.com/groeck/module-tests

I'll have to remove the driver first to get i2cdump to work on the chip. I
cannot force a device removal from user space while running, can I?
And i suppose you want a dump of a chip in running status? (On boot, all are
registers are simply set to zero)


Just use i2cdump -f while the driver is active.

Here's the dump (twice so you can see the A/D converter is actually running):

root@topic-miami-florida-pci-xc7z015:~# i2cdump -y -f -r 0-0xf 1 0x4c b
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 7f 1e 7f 7f 82 5f 80 44 80 44 80 3f 80 3f 89 b5 ?????_?D?D??????
root@topic-miami-florida-pci-xc7z015:~# i2cdump -y -f -r 0-0xf 1 0x4c b
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 7f 1e 7f 7f 82 65 80 42 80 42 80 3d 80 3d 89 b4 ?????e?B?B?=?=??




Kind regards,

Mike Looijmans
System Expert

TOPIC Embedded Products
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: +31 (0) 499 33 69 79
E-mail: mike.looijmans@xxxxxxxxxxxxxxxxx
Website: www.topicproducts.com

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