xlla
commented
4 years ago Closed xlla closed 4 years ago
xlla
commented
4 years ago 
htot
commented
4 years ago Again seems specific to your build. I have:
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage0_raw
61
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage1_raw
7
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage2_raw
5
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage3_raw
4
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage4_raw
2816
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage5_raw
2261
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage6_raw
2063
root@edison:~# cat /sys/bus/iio/devices/iio\:device1/in_voltage7_raw
58I don't know what cause that. I found iio could not read channel except ch0 too.
root@edison:~# iio_info
Library version: 0.15 (git tag: v0.15)
Compiled with backends: local xml ip usb
IIO context created with local backend.
Backend version: 0.15 (git tag: v0.15)
Backend description string: Linux edison 5.5.0-edison-acpi-standard #1 SMP Tue Apr 7 08:01:25 UTC 2020 i686
IIO context has 1 attributes:
local,kernel: 5.5.0-edison-acpi-standard
IIO context has 3 devices:
iio:device1: ads7951 (buffer capable)
9 channels found:
voltage0: (input, index: 0, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 21
attr 1: scale value: 2.442002442
voltage1: (input, index: 1, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage2: (input, index: 2, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage3: (input, index: 3, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage4: (input, index: 4, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage5: (input, index: 5, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage6: (input, index: 6, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage7: (input, index: 7, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
timestamp: (input, index: 8, format: le:S64/64>>0)
1 device-specific attributes found:
attr 0: current_timestamp_clock value: realtime
2 buffer-specific attributes found:
attr 0: watermark value: 1
attr 1: data_available value: 0
iio:device0: mrfld_bcove_adc
9 channels found:
temp6: (input)
1 channel-specific attributes found:
attr 0: raw value: 304
voltage0: (input)
1 channel-specific attributes found:
attr 0: raw value: 987
temp3: (input)
1 channel-specific attributes found:
attr 0: raw value: 478
temp7: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
temp4: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
temp8: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
resistance1: (input)
1 channel-specific attributes found:
attr 0: raw value: 1020
temp5: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
current2: (input)
1 channel-specific attributes found:
attr 0: raw value: 513
iio_sysfs_trigger:
0 channels found:
2 device-specific attributes found:
attr 0: add_trigger ERROR: Permission denied (-13)
attr 1: remove_trigger ERROR: Permission denied (-13)
and I found same error in your post here, only raw value in voltage0 was read (8)
htot
commented
4 years ago and I found same error in your post here,
Good point, I forgot about that, I don't know how that got fixed.
htot
commented
4 years ago So I have:
root@edison:~# iio_info
Library version: 0.15 (git tag: v0.15)
Compiled with backends: local xml ip usb
IIO context created with local backend.
Backend version: 0.15 (git tag: v0.15)
Backend description string: Linux edison 5.5.0-edison-acpi-standard #1 SMP Thu Apr 2 20:06:36 UTC 2020 x86_64
IIO context has 1 attributes:
local,kernel: 5.5.0-edison-acpi-standard
IIO context has 3 devices:
iio_sysfs_trigger:
0 channels found:
2 device-specific attributes found:
attr 0: remove_trigger ERROR: Permission denied (-13)
attr 1: add_trigger ERROR: Permission denied (-13)
iio:device1: ads7951 (buffer capable)
9 channels found:
voltage0: (input, index: 0, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 17
attr 1: scale value: 2.442002442
voltage1: (input, index: 1, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 6
attr 1: scale value: 2.442002442
voltage2: (input, index: 2, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 6
attr 1: scale value: 2.442002442
voltage3: (input, index: 3, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 4
attr 1: scale value: 2.442002442
voltage4: (input, index: 4, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 3034
attr 1: scale value: 2.442002442
voltage5: (input, index: 5, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 2465
attr 1: scale value: 2.442002442
voltage6: (input, index: 6, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 1179
attr 1: scale value: 2.442002442
voltage7: (input, index: 7, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 192
attr 1: scale value: 2.442002442
timestamp: (input, index: 8, format: le:S64/64>>0)
1 device-specific attributes found:
attr 0: current_timestamp_clock value: realtime
2 buffer-specific attributes found:
attr 0: watermark value: 1
attr 1: data_available value: 0
iio:device0: mrfld_bcove_adc
9 channels found:
temp3: (input)
1 channel-specific attributes found:
attr 0: raw value: 0
temp7: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
current2: (input)
1 channel-specific attributes found:
attr 0: raw value: 510
temp4: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
temp8: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
temp5: (input)
1 channel-specific attributes found:
attr 0: raw value: 1
resistance1: (input)
1 channel-specific attributes found:
attr 0: raw value: 0
temp6: (input)
1 channel-specific attributes found:
attr 0: raw value: 334
voltage0: (input)
1 channel-specific attributes found:
attr 0: raw value: 981
Note: the order of devices is not the same. I am using x86_64, you i686.
My meta-acpi is at a4692530. And you?
xlla
commented
4 years ago I have tested same firmware in another Edison, same result. I guess it maybe caused by manual acpi-table-load, can you disable kernel and service acpi load, do acpi-table-load in shell, then check the result?
xlla
commented
4 years ago and I have combine all asl files into one.
root@edison:~# ls -al /sys/kernel/config/acpi/table total 0 drwxr-xr-x 3 root root 0 Apr 10 15:37 . drwxr-xr-x 3 root root 0 Jan 1 2000 .. drwxr-xr-x 2 root root 0 Apr 10 15:37 oled-spi-leds
when I do acpi-table-load, it will complain
gpioset: at least one GPIO line offset to value mapping must be specified gpioset: at least one GPIO line offset to value mapping must be specified
if I change sleep .2 to .5, it will find tristate line, but the characters on spi oled screen become big and mistiness.
if I comment statement to skip pull down tristate line, and do acpi-table-load again, the spi oled screen works fine.
xlla
commented
4 years ago I thought the logic of acpi-table-load is not obey the edison arduino hardware guide,
Assert the tri_state_all signal to disconnect the shield pins set mux/bias/soc mode De-assert the tri_state_all signal to reconnect the shield pins
current flow is, set mux/bias/soc mode Assert the tri_state_all De-assert the tri_state_all
is it safety? I found that quickly pull down/up tri_state_all after ssdt load will muss spi fb. @andy-shev
xlla
commented
4 years ago I look into the ti-ads7950, ret = ti_ads7950_scan_direct(indio_dev, chan->address)
Note: the order of devices is not the same. I am using
x86_64, youi686
it seems the cause, I have add a lot of trace statements into ads7950, found it will check data address when got a data in function ti_ads7950_read_raw, only ch0 has a match address, if I force it omit address check, then iio will read some wrong data but successful.
iio:device1: ads7951 (buffer capable)
9 channels found:
voltage0: (input, index: 0, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 24
attr 1: scale value: 2.442002442
voltage1: (input, index: 1, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 2054
attr 1: scale value: 2.442002442
voltage2: (input, index: 2, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 5
attr 1: scale value: 2.442002442
voltage3: (input, index: 3, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 2052
attr 1: scale value: 2.442002442
voltage4: (input, index: 4, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 15
attr 1: scale value: 2.442002442
voltage5: (input, index: 5, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 2062
attr 1: scale value: 2.442002442
voltage6: (input, index: 6, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 0
attr 1: scale value: 2.442002442
voltage7: (input, index: 7, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 2085
attr 1: scale value: 2.442002442
timestamp: (input, index: 8, format: le:S64/64>>0)
1 device-specific attributes found:
attr 0: current_timestamp_clock value: realtime
2 buffer-specific attributes found:
attr 0: watermark value: 1
attr 1: data_available value: 0
and here is the log, for each channel, address[x] is actual address, expect addr[y] is expect address. the pattern like, ch0,ch1 want y 0 ch2,ch3 want y 1 ch4,ch5 want y 2 ch6, ch7 want y 3
like a 64bit address be treated as 2 32 bit address in somewhere.
[ 107.762281] ads7950 read raw: ch[0]. [ 107.762290] ads7950 read raw, scan direct, address [0]. [ 107.762295] ads7950 scan dir, ch [0]. [ 107.762301] ads7950 scan dir, cmd [1000] [ 107.762600] ads7950 scan dir, ret [0]. [ 107.762607] ads7950 scan dir, rx [24]. [ 107.762612] ads7950 read raw, expect addr[0]. [ 107.762617] ads7950 read raw, val [24]. [ 107.762839] ads7950 read raw: ch[0]. [ 107.762846] ads7950 read raw, scale. [ 107.763236] ads7950 read raw: ch[1]. [ 107.763244] ads7950 read raw, scan direct, address [1]. [ 107.763248] ads7950 scan dir, ch [1]. [ 107.763254] ads7950 scan dir, cmd [1080] [ 107.763522] ads7950 scan dir, ret [0]. [ 107.763529] ads7950 scan dir, rx [2054]. [ 107.763534] ads7950 read raw, expect addr[0]. [ 107.763539] ads7950 read raw, val [2054]. [ 107.763753] ads7950 read raw: ch[0]. [ 107.763759] ads7950 read raw, scale. [ 107.764094] ads7950 read raw: ch[2]. [ 107.764102] ads7950 read raw, scan direct, address [2]. [ 107.764106] ads7950 scan dir, ch [2]. [ 107.764112] ads7950 scan dir, cmd [1100] [ 107.764354] ads7950 scan dir, ret [0]. [ 107.764361] ads7950 scan dir, rx [4101]. [ 107.764366] ads7950 read raw, expect addr[1]. [ 107.764370] ads7950 read raw, val [5]. [ 107.764582] ads7950 read raw: ch[0]. [ 107.764588] ads7950 read raw, scale. [ 107.764863] ads7950 read raw: ch[3]. [ 107.764884] ads7950 read raw, scan direct, address [3]. [ 107.764903] ads7950 scan dir, ch [3]. [ 107.764960] ads7950 scan dir, cmd [1180] [ 107.765200] ads7950 scan dir, ret [0]. [ 107.765207] ads7950 scan dir, rx [6148]. [ 107.765212] ads7950 read raw, expect addr[1]. [ 107.765217] ads7950 read raw, val [2052]. [ 107.765429] ads7950 read raw: ch[0]. [ 107.765435] ads7950 read raw, scale. [ 107.765708] ads7950 read raw: ch[4]. [ 107.765715] ads7950 read raw, scan direct, address [4]. [ 107.765720] ads7950 scan dir, ch [4]. [ 107.765725] ads7950 scan dir, cmd [1200] [ 107.766030] ads7950 scan dir, ret [0]. [ 107.766037] ads7950 scan dir, rx [8207]. [ 107.766042] ads7950 read raw, expect addr[2]. [ 107.766047] ads7950 read raw, val [15]. [ 107.766266] ads7950 read raw: ch[0]. [ 107.766285] ads7950 read raw, scale. [ 107.766569] ads7950 read raw: ch[5]. [ 107.766576] ads7950 read raw, scan direct, address [5]. [ 107.766581] ads7950 scan dir, ch [5]. [ 107.766587] ads7950 scan dir, cmd [1280] [ 107.768279] ads7950 scan dir, ret [0]. [ 107.768288] ads7950 scan dir, rx [10254]. [ 107.768293] ads7950 read raw, expect addr[2]. [ 107.768299] ads7950 read raw, val [2062]. [ 107.768544] ads7950 read raw: ch[0]. [ 107.768550] ads7950 read raw, scale. [ 107.768837] ads7950 read raw: ch[6]. [ 107.768845] ads7950 read raw, scan direct, address [6]. [ 107.768849] ads7950 scan dir, ch [6]. [ 107.768855] ads7950 scan dir, cmd [1300] [ 107.770064] ads7950 scan dir, ret [0]. [ 107.770073] ads7950 scan dir, rx [12288]. [ 107.770078] ads7950 read raw, expect addr[3]. [ 107.770083] ads7950 read raw, val [0]. [ 107.770307] ads7950 read raw: ch[0]. [ 107.770313] ads7950 read raw, scale. [ 107.770591] ads7950 read raw: ch[7]. [ 107.770599] ads7950 read raw, scan direct, address [7]. [ 107.770604] ads7950 scan dir, ch [7]. [ 107.770620] ads7950 scan dir, cmd [1380] [ 107.770905] ads7950 scan dir, ret [0]. [ 107.770962] ads7950 scan dir, rx [14373]. [ 107.770968] ads7950 read raw, expect addr[3]. [ 107.770973] ads7950 read raw, val [2085]. [ 107.771187] ads7950 read raw: ch[0]. [ 107.771193] ads7950 read raw, scale.
xlla
commented
4 years ago ads7951 use 20Mhz clock, my spi screen use 1Mhz clock, are they interfere each other?
xlla
commented
4 years ago @andy-shev , please help me to check this. I have read the code of ti-ads7950 and add some trace log to observe what happened to other channels, see above log.
it seems read from spi bus is ok, but address check failure, I printed the return value of ti_ads7950_scan_direct in "ads7950 scan dir, rx [xxx]" in dec.
when I convert them to hex, I found some bits looks very like actual address.
24 | 18 2054 | 806 4101 | 1005 6148 | 1804 8207 | 200F 10254 | 280E 12288 | 3000 14373 | 3825
if shift them right 11bit, then remain address seems matches channel.
24 | 18 | 0 | 0 2054 | 806 | 1 | 1 4101 | 1005 | 10 | 2 6148 | 1804 | 11 | 3 8207 | 200F | 100 | 4 10254 | 280E | 101 | 5 12288 | 3000 | 110 | 6 14373 | 3825 | 111 | 7
then I change hardcode 12 to 11 in macro TI_ADS7950_EXTRACT call, it is work. each channel data look normal.
root@edison:~# iio_info
Library version: 0.15 (git tag: v0.15)
Compiled with backends: local xml ip usb
IIO context created with local backend.
Backend version: 0.15 (git tag: v0.15)
Backend description string: Linux edison 5.5.0-edison-acpi-standard #1 SMP Wed Apr 8 08:29:05 UTC 2020 i686
IIO context has 1 attributes:
local,kernel: 5.5.0-edison-acpi-standard
IIO context has 3 devices:
iio:device1: ads7951 (buffer capable)
9 channels found:
voltage0: (input, index: 0, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 24
attr 1: scale value: 2.442002442
voltage1: (input, index: 1, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 9
attr 1: scale value: 2.442002442
voltage2: (input, index: 2, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 6
attr 1: scale value: 2.442002442
voltage3: (input, index: 3, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 4
attr 1: scale value: 2.442002442
voltage4: (input, index: 4, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 16
attr 1: scale value: 2.442002442
voltage5: (input, index: 5, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 14
attr 1: scale value: 2.442002442
voltage6: (input, index: 6, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 0
attr 1: scale value: 2.442002442
voltage7: (input, index: 7, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 36
attr 1: scale value: 2.442002442
timestamp: (input, index: 8, format: le:S64/64>>0)
1 device-specific attributes found:
attr 0: current_timestamp_clock value: realtime
2 buffer-specific attributes found:
attr 0: watermark value: 1
attr 1: data_available value: 0
xlla
commented
4 years ago since @htot has report work fine on x86_64 for hardcode 12, is there any method to determine this hardcode dynamically?
the usage of ti-ads795x chip using kernel driver is merely in google search result, I can't find more information about this. In kernel repo, I can't create any issue, so I have to ask question here.
andy-shev
commented
4 years ago @xlla Unfortunately I have no access to the hardware till the Tuesday next week. Can you do the same dump in x86_64 environment (please use hex numbers where it makes sense)?
andy-shev
commented
4 years ago @xlla and can you share all your patches to debug? (Perhaps as a branch in you kernel repository)
Honestly, I don't see a problem in this driver, it might be somewhere else.
andy-shev
commented
4 years ago This actually is interesting part...
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
u16 rx_buf[TI_ADS7950_MAX_CHAN + 2 + TI_ADS7950_TIMESTAMP_SIZE]
____cacheline_aligned;
u16 tx_buf[TI_ADS7950_MAX_CHAN + 2];
u16 single_tx;
u16 single_rx;Recently driver gained single short support and these single_* had been added, though in case of Edison the small transfers (less than DMA burst, which is 8 bytes) should go via PIO mode. So, still no explanation for the bit shift.
andy-shev
commented
4 years ago @xlla
Another possible explanation is the CS signal phase (need oscilloscope to check) is deviating and thus the first (least significant) bit of measurement gone.
Ah, also you may drop the frequency to 10MHz and see if it helps. The chip is 20MHz compatible and SPI driver should put a divisor to guarantee that clock is not bigger than asked (in Edison case I think it's 16.667MHz), but still PCB can interfere with this frequency somehow.
In any case 12 in the driver seems in accordance with data sheet. So, can't be changed.
xlla
commented
4 years ago my branch is here.
for @htot 's iio_info log, if there is nothing connected to A4/A5, then the raw values of A4/A5 is abnormal. for my fixed version, A0-A5 is all close to zero.
I have connected a ML8511 sensor to edison, measured voltage on A0/A1 is correct compare to multimeter.
I am afraid I couldn't switch to x86_64 now, there is no enough hd space to build another huge set of firmware/recipes, and I can image there must be a lot things to do to adapt x86_64 for my in progress kernel.
xlla
commented
4 years ago Another possible explanation is the CS signal phase (need oscilloscope to check) is deviating and thus the first (least significant) bit of measurement gone.
as I questioned, ads use 20Mhz clock, oled use 1Mhz clock, how do they coordinate in same clk line.
andy-shev
commented
4 years ago Another possible explanation is the CS signal phase (need oscilloscope to check) is deviating and thus the first (least significant) bit of measurement gone.
as I questioned, ads use 20Mhz clock, oled use 1Mhz clock, how do they coordinate in same clk line.
@xlla
Based on so called SPI messages. The clock is getting setup per each message.
On top of that chip select defines a target on hardware (signal) level.
andy-shev
commented
4 years ago @xlla Can you update the debug log based on your latest patches?
xlla
commented
4 years ago @andy-shev trigger here A0 - ML8511 out, A1 - 3.3v, used for vref
root@edison:/mnt/study/test# iio_info
Library version: 0.15 (git tag: v0.15)
Compiled with backends: local xml ip usb
IIO context created with local backend.
Backend version: 0.15 (git tag: v0.15)
Backend description string: Linux edison 5.5.0-edison-acpi-standard #1 SMP Wed Apr 8 08:29:05 UTC 2020 i686
IIO context has 1 attributes:
local,kernel: 5.5.0-edison-acpi-standard
IIO context has 3 devices:
iio:device1: ads7951 (buffer capable)
9 channels found:
voltage0: (input, index: 0, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 606
attr 1: scale value: 2.442002442
voltage1: (input, index: 1, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 1967
attr 1: scale value: 2.442002442
voltage2: (input, index: 2, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 83
attr 1: scale value: 2.442002442
voltage3: (input, index: 3, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 11
attr 1: scale value: 2.442002442
voltage4: (input, index: 4, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 19
attr 1: scale value: 2.442002442
voltage5: (input, index: 5, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 17
attr 1: scale value: 2.442002442
voltage6: (input, index: 6, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 0
attr 1: scale value: 2.442002442
voltage7: (input, index: 7, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 37
attr 1: scale value: 2.442002442
timestamp: (input, index: 8, format: le:S64/64>>0)
1 device-specific attributes found:
attr 0: current_timestamp_clock value: realtime
[16431.983482] ads7950 read raw: ch[0]. [16431.983491] ads7950 read raw, scale. [16431.983699] ads7950 read raw: ch[0]. [16431.983705] ads7950 read raw, scale. [16431.984526] ads7950 read raw: ch[0]. [16431.984533] ads7950 read raw, scale. [16431.984723] ads7950 read raw: ch[0]. [16431.984729] ads7950 read raw, scale. [16431.984981] ads7950 read raw: ch[0]. [16431.984987] ads7950 read raw, scale. [16431.985162] ads7950 read raw: ch[0]. [16431.985168] ads7950 read raw, scale. [16431.985341] ads7950 read raw: ch[0]. [16431.985347] ads7950 read raw, scale. [16431.985520] ads7950 read raw: ch[0]. [16431.985526] ads7950 read raw, scale. [16431.987509] ads7950 read raw: ch[0]. [16431.987518] ads7950 read raw, scan direct, address [0]. [16431.987524] ads7950 scan dir, ch [0]. [16431.987530] ads7950 scan dir, cmd [1000] [16431.987824] ads7950 scan dir, ret [0]. [16431.987903] ads7950 scan dir, rx [606]. [16431.987911] ads7950 read raw, ret[606] expect addr[0]. [16431.987916] ads7950 read raw, (8,4) addr[25e]. [16431.987923] ads7950 read raw, shift[0], realbits[12], val [606]. [16431.988149] ads7950 read raw: ch[0]. [16431.988155] ads7950 read raw, scale. [16431.988471] ads7950 read raw: ch[1]. [16431.988479] ads7950 read raw, scan direct, address [1]. [16431.988483] ads7950 scan dir, ch [1]. [16431.988489] ads7950 scan dir, cmd [1080] [16431.991674] ads7950 scan dir, ret [0]. [16431.991683] ads7950 scan dir, rx [4015]. [16431.991690] ads7950 read raw, ret[4015] expect addr[0]. [16431.991695] ads7950 read raw, (8,4) addr[faf]. [16431.991702] ads7950 read raw, shift[0], realbits[12], val [1967]. [16431.992965] ads7950 read raw: ch[0]. [16431.992972] ads7950 read raw, scale. [16431.993262] ads7950 read raw: ch[2]. [16431.993269] ads7950 read raw, scan direct, address [2]. [16431.993274] ads7950 scan dir, ch [2]. [16431.993280] ads7950 scan dir, cmd [1100] [16431.993548] ads7950 scan dir, ret [0]. [16431.993555] ads7950 scan dir, rx [4179]. [16431.993562] ads7950 read raw, ret[4179] expect addr[1]. [16431.993567] ads7950 read raw, (8,4) addr[1053]. [16431.993574] ads7950 read raw, shift[0], realbits[12], val [83]. [16431.993792] ads7950 read raw: ch[0]. [16431.993798] ads7950 read raw, scale. [16431.996355] ads7950 read raw: ch[3]. [16431.996364] ads7950 read raw, scan direct, address [3]. [16431.996369] ads7950 scan dir, ch [3]. [16431.996375] ads7950 scan dir, cmd [1180] [16431.996640] ads7950 scan dir, ret [0]. [16431.996647] ads7950 scan dir, rx [6155]. [16431.996654] ads7950 read raw, ret[6155] expect addr[1]. [16431.996659] ads7950 read raw, (8,4) addr[180b]. [16431.996666] ads7950 read raw, shift[0], realbits[12], val [11]. [16431.998449] ads7950 read raw: ch[0]. [16431.998456] ads7950 read raw, scale. [16431.998744] ads7950 read raw: ch[4]. [16431.998752] ads7950 read raw, scan direct, address [4]. [16431.998757] ads7950 scan dir, ch [4]. [16431.998764] ads7950 scan dir, cmd [1200] [16432.000091] ads7950 scan dir, ret [0]. [16432.000099] ads7950 scan dir, rx [8211]. [16432.000105] ads7950 read raw, ret[8211] expect addr[2]. [16432.000111] ads7950 read raw, (8,4) addr[2013]. [16432.000117] ads7950 read raw, shift[0], realbits[12], val [19]. [16432.000348] ads7950 read raw: ch[0]. [16432.000354] ads7950 read raw, scale. [16432.000633] ads7950 read raw: ch[5]. [16432.000641] ads7950 read raw, scan direct, address [5]. [16432.000646] ads7950 scan dir, ch [5]. [16432.000651] ads7950 scan dir, cmd [1280] [16432.002658] ads7950 scan dir, ret [0]. [16432.002666] ads7950 scan dir, rx [10257]. [16432.002673] ads7950 read raw, ret[10257] expect addr[2]. [16432.002678] ads7950 read raw, (8,4) addr[2811]. [16432.002685] ads7950 read raw, shift[0], realbits[12], val [17]. [16432.003862] ads7950 read raw: ch[0]. [16432.003870] ads7950 read raw, scale. [16432.004156] ads7950 read raw: ch[6]. [16432.004164] ads7950 read raw, scan direct, address [6]. [16432.004168] ads7950 scan dir, ch [6]. [16432.004174] ads7950 scan dir, cmd [1300] [16432.004445] ads7950 scan dir, ret [0]. [16432.004452] ads7950 scan dir, rx [12288]. [16432.004459] ads7950 read raw, ret[12288] expect addr[3]. [16432.004464] ads7950 read raw, (8,4) addr[3000]. [16432.004470] ads7950 read raw, shift[0], realbits[12], val [0]. [16432.004692] ads7950 read raw: ch[0]. [16432.004698] ads7950 read raw, scale. [16432.007214] ads7950 read raw: ch[7]. [16432.007223] ads7950 read raw, scan direct, address [7]. [16432.007228] ads7950 scan dir, ch [7]. [16432.007234] ads7950 scan dir, cmd [1380] [16432.007494] ads7950 scan dir, ret [0]. [16432.007501] ads7950 scan dir, rx [14373]. [16432.007508] ads7950 read raw, ret[14373] expect addr[3]. [16432.007513] ads7950 read raw, (8,4) addr[3825]. [16432.007520] ads7950 read raw, shift[0], realbits[12], val [37]. [16432.007749] ads7950 read raw: ch[0]. [16432.007755] ads7950 read raw, scale.
"ads7950 read raw, (8,4)" should be "ads7950 read raw, (11,4)", is a typo.
andy-shev
commented
4 years ago @xlla
Can you try to apply this patch (https://github.com/andy-shev/linux/commit/e436e0f9274ae0fe28faf0c9af720b8ffc0fc98b) against kernel and this one (https://github.com/westeri/meta-acpi/commit/2709b5021bb23502c95c7c44e606e598cc43bb87) against ASL code and test if it helps?
xlla
commented
4 years ago Hi @andy-shev , I'v apply those patches and deploy to edison, here is the log.
root@edison:~# iio_info
Library version: 0.15 (git tag: v0.15)
Compiled with backends: local xml ip usb
IIO context created with local backend.
Backend version: 0.15 (git tag: v0.15)
Backend description string: Linux edison 5.5.0-edison-acpi-standard #1 SMP Wed Apr 8 08:29:05 UTC 2020 i686
IIO context has 1 attributes:
local,kernel: 5.5.0-edison-acpi-standard
IIO context has 3 devices:
iio:device1: ads7951 (buffer capable)
9 channels found:
voltage0: (input, index: 0, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 605
attr 1: scale value: 2.442002442
voltage1: (input, index: 1, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 1969
attr 1: scale value: 2.442002442
voltage2: (input, index: 2, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 83
attr 1: scale value: 2.442002442
voltage3: (input, index: 3, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 11
attr 1: scale value: 2.442002442
voltage4: (input, index: 4, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 11
attr 1: scale value: 2.442002442
voltage5: (input, index: 5, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 10
attr 1: scale value: 2.442002442
voltage6: (input, index: 6, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 0
attr 1: scale value: 2.442002442
voltage7: (input, index: 7, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 35
attr 1: scale value: 2.442002442
timestamp: (input, index: 8, format: le:S64/64>>0)
1 device-specific attributes found:
attr 0: current_timestamp_clock value: realtime
2 buffer-specific attributes found:
attr 0: watermark value: 1
attr 1: data_available value: 0
iio:device0: mrfld_bcove_adc
root@edison:~# dmesg|grep ads [ 0.090550] process: using mwait in idle threads [ 46.892913] ads7950 init... [ 46.892967] ads7950 [ads7951], channels [9]. [ 46.892974] ads7950 vref_mv [5000]. [ 46.892999] ads7950 spi-PRP0001:00: spi-PRP0001:00 supply vref not found, using dummy regulator [ 46.893109] ads7950 vref ok. [ 46.893130] ads7950 triggered buffer ok. [ 46.897813] ads7950 adc chip ok. [ 46.902345] ads7950 add gpio chip[spi-PRP0001:00]. [ 46.903858] ads7950 ready. [ 51.254389] ads7950 read raw: ch[0]. [ 51.254398] ads7950 read raw, scale. [ 51.254701] ads7950 read raw: ch[0]. [ 51.254708] ads7950 read raw, scale. [ 51.254883] ads7950 read raw: ch[0]. [ 51.254889] ads7950 read raw, scale. [ 51.255060] ads7950 read raw: ch[0]. [ 51.255066] ads7950 read raw, scale. [ 51.255239] ads7950 read raw: ch[0]. [ 51.255245] ads7950 read raw, scale. [ 51.255473] ads7950 read raw: ch[0]. [ 51.255479] ads7950 read raw, scale. [ 51.255658] ads7950 read raw: ch[0]. [ 51.255664] ads7950 read raw, scale. [ 51.255838] ads7950 read raw: ch[0]. [ 51.255844] ads7950 read raw, scale. [ 51.257837] ads7950 read raw: ch[0]. [ 51.257846] ads7950 read raw, scan direct, address [0]. [ 51.257851] ads7950 scan dir, ch [0]. [ 51.257858] ads7950 scan dir, cmd [1000] [ 51.260654] ads7950 scan dir, ret [0]. [ 51.260664] ads7950 scan dir, rx [605]. [ 51.260671] ads7950 read raw, ret[605] expect addr[0]. [ 51.260677] ads7950 read raw, (8,4) addr[25d]. [ 51.260684] ads7950 read raw, shift[0], realbits[12], val [605]. [ 51.260940] ads7950 read raw: ch[0]. [ 51.260946] ads7950 read raw, scale. [ 51.261231] ads7950 read raw: ch[1]. [ 51.261239] ads7950 read raw, scan direct, address [1]. [ 51.261243] ads7950 scan dir, ch [1]. [ 51.261249] ads7950 scan dir, cmd [1080] [ 51.263374] ads7950 scan dir, ret [0]. [ 51.263382] ads7950 scan dir, rx [4017]. [ 51.263389] ads7950 read raw, ret[4017] expect addr[0]. [ 51.263394] ads7950 read raw, (8,4) addr[fb1]. [ 51.263401] ads7950 read raw, shift[0], realbits[12], val [1969]. [ 51.264643] ads7950 read raw: ch[0]. [ 51.264650] ads7950 read raw, scale. [ 51.264932] ads7950 read raw: ch[2]. [ 51.264940] ads7950 read raw, scan direct, address [2]. [ 51.264945] ads7950 scan dir, ch [2]. [ 51.264951] ads7950 scan dir, cmd [1100] [ 51.265244] ads7950 scan dir, ret [0]. [ 51.265251] ads7950 scan dir, rx [4179]. [ 51.265258] ads7950 read raw, ret[4179] expect addr[1]. [ 51.265263] ads7950 read raw, (8,4) addr[1053]. [ 51.265270] ads7950 read raw, shift[0], realbits[12], val [83]. [ 51.267301] ads7950 read raw: ch[0]. [ 51.267308] ads7950 read raw, scale. [ 51.268073] ads7950 read raw: ch[3]. [ 51.268082] ads7950 read raw, scan direct, address [3]. [ 51.268087] ads7950 scan dir, ch [3]. [ 51.268093] ads7950 scan dir, cmd [1180] [ 51.268390] ads7950 scan dir, ret [0]. [ 51.268397] ads7950 scan dir, rx [6155]. [ 51.268403] ads7950 read raw, ret[6155] expect addr[1]. [ 51.268408] ads7950 read raw, (8,4) addr[180b]. [ 51.268478] ads7950 read raw, shift[0], realbits[12], val [11]. [ 51.270200] ads7950 read raw: ch[0]. [ 51.270207] ads7950 read raw, scale. [ 51.270980] ads7950 read raw: ch[4]. [ 51.270988] ads7950 read raw, scan direct, address [4]. [ 51.270993] ads7950 scan dir, ch [4]. [ 51.270999] ads7950 scan dir, cmd [1200] [ 51.271287] ads7950 scan dir, ret [0]. [ 51.271295] ads7950 scan dir, rx [8203]. [ 51.271301] ads7950 read raw, ret[8203] expect addr[2]. [ 51.271306] ads7950 read raw, (8,4) addr[200b]. [ 51.271314] ads7950 read raw, shift[0], realbits[12], val [11]. [ 51.273041] ads7950 read raw: ch[0]. [ 51.273047] ads7950 read raw, scale. [ 51.273333] ads7950 read raw: ch[5]. [ 51.273340] ads7950 read raw, scan direct, address [5]. [ 51.273345] ads7950 scan dir, ch [5]. [ 51.273351] ads7950 scan dir, cmd [1280] [ 51.274724] ads7950 scan dir, ret [0]. [ 51.274733] ads7950 scan dir, rx [10250]. [ 51.274740] ads7950 read raw, ret[10250] expect addr[2]. [ 51.274745] ads7950 read raw, (8,4) addr[280a]. [ 51.274752] ads7950 read raw, shift[0], realbits[12], val [10]. [ 51.274976] ads7950 read raw: ch[0]. [ 51.274982] ads7950 read raw, scale. [ 51.275262] ads7950 read raw: ch[6]. [ 51.275269] ads7950 read raw, scan direct, address [6]. [ 51.275274] ads7950 scan dir, ch [6]. [ 51.275279] ads7950 scan dir, cmd [1300] [ 51.277375] ads7950 scan dir, ret [0]. [ 51.277384] ads7950 scan dir, rx [12288]. [ 51.277391] ads7950 read raw, ret[12288] expect addr[3]. [ 51.277396] ads7950 read raw, (8,4) addr[3000]. [ 51.277413] ads7950 read raw, shift[0], realbits[12], val [0]. [ 51.278633] ads7950 read raw: ch[0]. [ 51.278640] ads7950 read raw, scale. [ 51.278929] ads7950 read raw: ch[7]. [ 51.278936] ads7950 read raw, scan direct, address [7]. [ 51.278941] ads7950 scan dir, ch [7]. [ 51.278947] ads7950 scan dir, cmd [1380] [ 51.279223] ads7950 scan dir, ret [0]. [ 51.279231] ads7950 scan dir, rx [14371]. [ 51.279237] ads7950 read raw, ret[14371] expect addr[3]. [ 51.279243] ads7950 read raw, (8,4) addr[3823]. [ 51.279249] ads7950 read raw, shift[0], realbits[12], val [35]. [ 51.281513] ads7950 read raw: ch[0]. [ 51.281520] ads7950 read raw, scale.
xlla
commented
4 years ago Ah, also you may drop the frequency to 10MHz and see if it helps. The chip is 20MHz compatible and SPI driver should put a divisor to guarantee that clock is not bigger than asked (in Edison case I think it's 16.667MHz), but still PCB can interfere with this frequency somehow.
I tried this, it seems work. look my log, "all expect addr[x]", x is extracted by shift 12, it is matches the ch, since my actual check statement is still using 11 bit, so all values of ch which above 0 is error in iio_info.
root@edison:~# iio_info
Library version: 0.15 (git tag: v0.15)
Compiled with backends: local xml ip usb
IIO context created with local backend.
Backend version: 0.15 (git tag: v0.15)
Backend description string: Linux edison 5.5.0-edison-acpi-standard #1 SMP Wed Apr 8 08:29:05 UTC 2020 i686
IIO context has 1 attributes:
local,kernel: 5.5.0-edison-acpi-standard
IIO context has 3 devices:
iio:device1: ads7951 (buffer capable)
9 channels found:
voltage0: (input, index: 0, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw value: 1184
attr 1: scale value: 2.442002442
voltage1: (input, index: 1, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage2: (input, index: 2, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage3: (input, index: 3, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage4: (input, index: 4, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage5: (input, index: 5, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage6: (input, index: 6, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
voltage7: (input, index: 7, format: le:u12/16>>0)
2 channel-specific attributes found:
attr 0: raw ERROR: Input/output error (-5)
attr 1: scale value: 2.442002442
timestamp: (input, index: 8, format: le:S64/64>>0)
1 device-specific attributes found:
attr 0: current_timestamp_clock value: realtime
2 buffer-specific attributes found:
attr 0: watermark value: 1
[ 811.212409] ads7950 spi-PRP0001:00: Failed to retrieve ACPI GPIO chip [ 811.314914] ads7950 init... [ 811.314963] ads7950 [ads7951], channels [9]. [ 811.314970] ads7950 vref_mv [5000]. [ 811.314994] ads7950 spi-PRP0001:00: spi-PRP0001:00 supply vref not found, using dummy regulator [ 811.315088] ads7950 vref ok. [ 811.315109] ads7950 triggered buffer ok. [ 811.320423] ads7950 adc chip ok. [ 811.321761] ads7950 add gpio chip[spi-PRP0001:00]. [ 811.327584] ads7950 ready. [ 824.137621] ads7950 read raw: ch[0]. [ 824.137630] ads7950 read raw, scale. [ 824.138571] ads7950 read raw: ch[0]. [ 824.138579] ads7950 read raw, scale. [ 824.139247] ads7950 read raw: ch[0]. [ 824.139253] ads7950 read raw, scale. [ 824.139444] ads7950 read raw: ch[0]. [ 824.139451] ads7950 read raw, scale. [ 824.139625] ads7950 read raw: ch[0]. [ 824.139631] ads7950 read raw, scale. [ 824.139923] ads7950 read raw: ch[0]. [ 824.139930] ads7950 read raw, scale. [ 824.140734] ads7950 read raw: ch[0]. [ 824.140740] ads7950 read raw, scale. [ 824.140973] ads7950 read raw: ch[0]. [ 824.140980] ads7950 read raw, scale. [ 824.142863] ads7950 read raw: ch[0]. [ 824.142885] ads7950 read raw, scan direct, address [0]. [ 824.142900] ads7950 scan dir, ch [0]. [ 824.142907] ads7950 scan dir, cmd [1000] [ 824.143921] ads7950 scan dir, ret [0]. [ 824.143929] ads7950 scan dir, rx [1184]. [ 824.143936] ads7950 read raw, ret[1184] expect addr[0]. [ 824.143941] ads7950 read raw, (8,4) addr[4a0]. [ 824.143948] ads7950 read raw, shift[0], realbits[12], val [1184]. [ 824.144182] ads7950 read raw: ch[0]. [ 824.144190] ads7950 read raw, scale. [ 824.144469] ads7950 read raw: ch[1]. [ 824.144477] ads7950 read raw, scan direct, address [1]. [ 824.144481] ads7950 scan dir, ch [1]. [ 824.144487] ads7950 scan dir, cmd [1080] [ 824.144814] ads7950 scan dir, ret [0]. [ 824.144822] ads7950 scan dir, rx [8033]. [ 824.144828] ads7950 read raw, ret[8033] expect addr[1]. [ 824.144833] ads7950 read raw, (8,4) addr[1f61]. [ 824.146228] ads7950 read raw: ch[0]. [ 824.146245] ads7950 read raw, scale. [ 824.146530] ads7950 read raw: ch[2]. [ 824.146538] ads7950 read raw, scan direct, address [2]. [ 824.146542] ads7950 scan dir, ch [2]. [ 824.146548] ads7950 scan dir, cmd [1100] [ 824.148299] ads7950 scan dir, ret [0]. [ 824.148308] ads7950 scan dir, rx [8356]. [ 824.148314] ads7950 read raw, ret[8356] expect addr[2]. [ 824.148320] ads7950 read raw, (8,4) addr[20a4]. [ 824.148550] ads7950 read raw: ch[0]. [ 824.148556] ads7950 read raw, scale. [ 824.150267] ads7950 read raw: ch[3]. [ 824.150285] ads7950 read raw, scan direct, address [3]. [ 824.150290] ads7950 scan dir, ch [3]. [ 824.150296] ads7950 scan dir, cmd [1180] [ 824.150561] ads7950 scan dir, ret [0]. [ 824.150569] ads7950 scan dir, rx [12308]. [ 824.150575] ads7950 read raw, ret[12308] expect addr[3]. [ 824.150580] ads7950 read raw, (8,4) addr[3014]. [ 824.152657] ads7950 read raw: ch[0]. [ 824.152664] ads7950 read raw, scale. [ 824.153493] ads7950 read raw: ch[4]. [ 824.153502] ads7950 read raw, scan direct, address [4]. [ 824.153506] ads7950 scan dir, ch [4]. [ 824.153512] ads7950 scan dir, cmd [1200] [ 824.154720] ads7950 scan dir, ret [0]. [ 824.154729] ads7950 scan dir, rx [16406]. [ 824.154736] ads7950 read raw, ret[16406] expect addr[4]. [ 824.154741] ads7950 read raw, (8,4) addr[4016]. [ 824.155022] ads7950 read raw: ch[0]. [ 824.155029] ads7950 read raw, scale. [ 824.155306] ads7950 read raw: ch[5]. [ 824.155314] ads7950 read raw, scan direct, address [5]. [ 824.155319] ads7950 scan dir, ch [5]. [ 824.155324] ads7950 scan dir, cmd [1280] [ 824.157868] ads7950 scan dir, ret [0]. [ 824.157877] ads7950 scan dir, rx [20501]. [ 824.157883] ads7950 read raw, ret[20501] expect addr[5]. [ 824.157888] ads7950 read raw, (8,4) addr[5015]. [ 824.158114] ads7950 read raw: ch[0]. [ 824.158120] ads7950 read raw, scale. [ 824.158399] ads7950 read raw: ch[6]. [ 824.158407] ads7950 read raw, scan direct, address [6]. [ 824.158411] ads7950 scan dir, ch [6]. [ 824.158417] ads7950 scan dir, cmd [1300] [ 824.158681] ads7950 scan dir, ret [0]. [ 824.158688] ads7950 scan dir, rx [24576]. [ 824.158694] ads7950 read raw, ret[24576] expect addr[6]. [ 824.158699] ads7950 read raw, (8,4) addr[6000]. [ 824.162128] ads7950 read raw: ch[0]. [ 824.162135] ads7950 read raw, scale. [ 824.162416] ads7950 read raw: ch[7]. [ 824.162424] ads7950 read raw, scan direct, address [7]. [ 824.162429] ads7950 scan dir, ch [7]. [ 824.162435] ads7950 scan dir, cmd [1380] [ 824.162704] ads7950 scan dir, ret [0]. [ 824.162711] ads7950 scan dir, rx [28734]. [ 824.162718] ads7950 read raw, ret[28734] expect addr[7]. [ 824.162723] ads7950 read raw, (8,4) addr[703e]. [ 824.163005] ads7950 read raw: ch[0]. [ 824.163012] ads7950 read raw, scale.
andy-shev
commented
4 years ago @xlla Can you, please, test with original address extraction code?
xlla
commented
4 years ago @andy-shev from my above log No.2 in backward order, the original address extraction code result is [xxx] in those "ads7950 read raw, ret[6155] expect addr[xxx]."
for channel 3, it is 1 by original address extract code.
[ 51.268082] ads7950 read raw, scan direct, address [3]. [ 51.268087] ads7950 scan dir, ch [3]. [ 51.268093] ads7950 scan dir, cmd [1180] [ 51.268390] ads7950 scan dir, ret [0]. [ 51.268397] ads7950 scan dir, rx [6155]. [ 51.268403] ads7950 read raw, ret[6155] expect addr[1]. [ 51.268408] ads7950 read raw, (8,4) addr[180b]. [ 51.268478] ads7950 read raw, shift[0], realbits[12], val [11]. [ 51.270200] ads7950 read raw: ch[0]. [ 51.270207] ads7950 read raw, scale. [ 51.270980] ads7950 read raw: ch[4].
in this mraa manual , it said Max spi speed is 6.25Mhz, is it right? or for new linux kernel, it's performance improved?
andy-shev
commented
4 years ago @andy-shev from my above log No.2 in backward order, the original address extraction code result is [xxx] in those "ads7950 read raw, ret[6155] expect addr[xxx]."
for channel 3, it is 1 by original address extract code.
[ 51.268082] ads7950 read raw, scan direct, address [3]. [ 51.268087] ads7950 scan dir, ch [3]. [ 51.268093] ads7950 scan dir, cmd [1180] [ 51.268390] ads7950 scan dir, ret [0]. [ 51.268397] ads7950 scan dir, rx [6155]. [ 51.268403] ads7950 read raw, ret[6155] expect addr[1]. [ 51.268408] ads7950 read raw, (8,4) addr[180b]. [ 51.268478] ads7950 read raw, shift[0], realbits[12], val [11]. [ 51.270200] ads7950 read raw: ch[0]. [ 51.270207] ads7950 read raw, scale. [ 51.270980] ads7950 read raw: ch[4].
So, I didn't get. Do patch fix the issue or not?
in this mraa manual , it said Max spi speed is 6.25Mhz, is it right? or for new linux kernel, it's performance improved?
It always was up to 25MHz in hardware, the old BSP simple mistaken by unknown reasons.
htot
commented
4 years ago It always was up to 25MHz in hardware, the old BSP simple mistaken by unknown reasons.
Interesting. I thought SPI and HSU had similar max speeds. But SPI appears significantly faster.
xlla
commented
4 years ago So, I didn't get. Do patch fix the issue or not?
It is not fix the issue.
slow bus speed to 10Mhz eliminate the issue.
andy-shev
commented
4 years ago So, I didn't get. Do patch fix the issue or not?
It is not fix the issue.
In any case it's right thing to do. This ADC, as many others, is 16-bit word size.
slow bus speed to 10Mhz eliminate the issue.
A-ha, it's something. So, we need to have oscilloscope charts to understand what's going on there. JFYI: 20MHz is actually 12.5MHz since base clock is 25MHz, but it may be a bug somewhere and OS thinks wrong about actual bus speed.
So, I can update ASL for now with 10MHz speed until we will understand the issue clearly.
Or may be you prepare a patch with this simple change against meta-acpi?
xlla
commented
4 years ago @andy-shev I am connect edison to a usb-hub due to lack port of my computer, and the usb-hub was powered by a 5V adapter from AC socket, will it interfere with clock signal.
I only have a handheld oscilloscope, 40Mhz baudwidth, 250M samples/s.
I can observe oled's clock in 1Mhz, but can't watch ADC's.
the oled's clock signal is very noise and skipped every 2 seconds.
xlla
commented
4 years ago I realize that I must trigger ADC to do a read so it will transmit clock signal.
I write a simple app to continue read A0/A1, then I can do a measurement.
xlla
commented
4 years ago some article said, edison's main clock, If the SoC is in S0 state, 50Mhz If the SoC is in S0i2 state, 19.2Mhz If the SoC is in S0i3 state, 32Khz
for spi, as master, 25Mhz, as slave, 16.67Mhz
andy-shev
commented
4 years ago I realize that I must trigger ADC to do a read so it will transmit clock signal. I write a simple app to continue read A0/A1, then I can do a measurement.
Is it two channel oscilloscope? Because what we need is phase between SCK (Clock) and MISO (RxD) signals.
Ah, and SCK vs. CS, and MISO vs. CS. Basically we need all three wires (for read transfer) to see.
Because bug looks like one bit at the beginning or at the end of word transmission disappears.
some article said, edison's main clock, If the SoC is in S0 state, 50Mhz If the SoC is in S0i2 state, 19.2Mhz If the SoC is in S0i3 state, 32Khz
It is a system clock, I think it's actually 100MHz.
for spi, as master, 25Mhz,
Yes, that's what we have, 25, 12.5, 8.333, 6.25, ...
as slave, 16.67Mhz
That's I don't know.
xlla
commented
4 years ago sck vs miso
I don't know if it useful, so I just take one photo.
Yes, that's what we have, 25, 12.5, 8.333, 6.25, ...
should we set spi peripheral's clock aligning those clock, or we can set spi clock freely, like 1234.5678khz?
andy-shev
commented
4 years ago sck vs miso I don't know if it useful, so I just take one photo.
Yeah, we need better one. If I have time , I would check in our lab.
Yes, that's what we have, 25, 12.5, 8.333, 6.25, ...
should we set spi peripheral's clock aligning those clock, or we can set spi clock freely, like 1234.5678khz?
Freely. Driver will choose the nearest less than or equal to the requested one.
andy-shev
commented
4 years ago Colleague of mine has been investigating similar issue on another platform with another SPI controller. But he has, for his case, an idea that signal propagation thru level shifters and other discrete components might shift phase enough to get corrupted data. However, ADS7951 is connected directly to the SPI bus without any discrete components in between. My colleague also found that even with simple external loopback another platform fails at higher frequencies. So, it means somebody has to look to the electrical specifications of the GPIO / pin control buffers and muxes used inside SoC. It might be phase delay because of them. In any case, I have updated the frequency in the ASL code to be 10MHz and it seems working realiably.
htot
commented
4 years ago That sounds reasonable, 25MHz is not a low frequency especially if SPI lines are loaded by capacitance from the external wiring.
In other projects I found it is easy to get the clock polarity wrong, and then communication still works until you get a capacitive load on the lines. But in those cases reducing clock frequency usually does not help.
xlla
commented
4 years ago @andy-shev I am glad to heard that so I can stick on 32bit kernel with confidence.