Re: [PATCH v1 1/1] iio: adc: tlc4541: add support for TI tlc4541 adc

On 11/01/2017 17:17, Peter Meerwald-Stadler wrote:

On Wed, 11 Jan 2017, Phil Reid wrote:

quoted

Oops, title should be PATCH V2.

On 11/01/2017 14:51, Phil Reid wrote:

quoted

This adds TI's tlc4541 16-bit ADC driver. Which is a single channel
ADC. Supports raw and trigger buffer access.
Also supports the tlc3541 14-bit device, which has not been tested.
Implementation of the tlc3541 is fairly straight forward thou.

comments below

quoted

quoted

Signed-off-by: Phil Reid <preid-qgqNFa1JUf/o2iN0hyhwsIdd74u8MsAO@public.gmane.org>
---

Notes:
    Changes from v1:
    - Add tlc3541 support and chan spec.
    - remove fields that where already 0 from TLC4541_V_CHAN macro
    - Increase rx_buf size in tlc4541_state to avoid copy in
tlc4541_trigger_handle
    - Remove erroneous be16_to_cpu in tlc4541_trigger_handle
    - Docs/binding: spi -> SPI & add ti,tlc3541

    I haven't add Rob's Ack due to adding a new compatible string.

    I tried to ".index = 1" from the spec as suggested by Peter, but that
didn't
    seem to work. Perhaps remove of .channel was the intended target.

the only between index = 0/1 should be that the channel is called
in_voltage0_raw vs in_voltage_raw in sysfs -- maybe there is an issue in
iio_readdev?

Did a little more testing and the problem looks to be in libiio.


Here's the output from iio and list of sysfs files when "indexed = 1"
        iio:device8: tlc4541 (buffer capable)
                2 channels found:
                        voltage0:  (input, index: 0, format: be:U16/16>>0)
                        2 channel-specific attributes found:
                                attr 0: raw value: 174
                                attr 1: scale value: 0.076293945
                        timestamp:  (input, index: 1, format: le:S64/64>>0)
                1 device-specific attributes found:
                                attr 0: current_timestamp_clock value: realtime

root@cyclone5:~# ls /sys/bus/iio/devices/iio\:device8/*
/sys/bus/iio/devices/iio:device8/current_timestamp_clock  /sys/bus/iio/devices/iio:device8/in_voltage_scale
/sys/bus/iio/devices/iio:device8/dev                      /sys/bus/iio/devices/iio:device8/name
/sys/bus/iio/devices/iio:device8/in_voltage0_raw          /sys/bus/iio/devices/iio:device8/uevent

/sys/bus/iio/devices/iio:device8/buffer:
enable     length     watermark

/sys/bus/iio/devices/iio:device8/of_node:
#io-channel-cells  enable-dma         name               reg                spi-max-frequency
compatible         linux,phandle      phandle            spi-cpha           vref-supply

/sys/bus/iio/devices/iio:device8/power:
autosuspend_delay_ms    control                 runtime_active_time     runtime_status          runtime_suspended_time

/sys/bus/iio/devices/iio:device8/scan_elements:
in_timestamp_en     in_timestamp_index  in_timestamp_type   in_voltage0_en      in_voltage0_index   in_voltage0_type

/sys/bus/iio/devices/iio:device8/subsystem:
devices            drivers            drivers_autoprobe  drivers_probe      uevent

/sys/bus/iio/devices/iio:device8/trigger:
current_trigger

And the same when "indexed = 0"

        iio:device8: tlc4541 (buffer capable)
                2 channels found:
                        voltage:  (input)
                        2 channel-specific attributes found:
                                attr 0: raw value: 173
                                attr 1: scale value: 0.076293945
                        timestamp:  (input, index: 1, format: le:S64/64>>0)
                1 device-specific attributes found:
                                attr 0: current_timestamp_clock value: realtime

root@cyclone5:~# ls /sys/bus/iio/devices/iio\:device8/*
/sys/bus/iio/devices/iio:device8/current_timestamp_clock  /sys/bus/iio/devices/iio:device8/in_voltage_scale
/sys/bus/iio/devices/iio:device8/dev                      /sys/bus/iio/devices/iio:device8/name
/sys/bus/iio/devices/iio:device8/in_voltage_raw           /sys/bus/iio/devices/iio:device8/uevent

/sys/bus/iio/devices/iio:device8/buffer:
enable     length     watermark

/sys/bus/iio/devices/iio:device8/of_node:
#io-channel-cells  enable-dma         name               reg                spi-max-frequency
compatible         linux,phandle      phandle            spi-cpha           vref-supply

/sys/bus/iio/devices/iio:device8/power:
autosuspend_delay_ms    control                 runtime_active_time     runtime_status          runtime_suspended_time

/sys/bus/iio/devices/iio:device8/scan_elements:
in_timestamp_en     in_timestamp_index  in_timestamp_type   in_voltage_en       in_voltage_index    in_voltage_type

/sys/bus/iio/devices/iio:device8/subsystem:
devices            drivers            drivers_autoprobe  drivers_probe      uevent

/sys/bus/iio/devices/iio:device8/trigger:
current_trigger

The iio scope application also does not allow the tlc4541 channel to be selected when "indexed = 0".

I've had a bit of play with some test apps but it looks like to me libiio is not parsing the
scan_elements folder correctly when the channels are not indexed.
Haven't located exactly where as yet.

So is the correct path here to fix libiio?

I'm using libiio from git build a few weeks ago, I'll try updating to see if it fixes anything.
Last commit was:
9838779 - Paul Cercueil       , 3 weeks ago  : Local backend: Return scan result even if 0 devices







-- 
Regards
Phil Reid


--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html