How to use RTC3231 (Sorry wrong category see Linux)


#1

Hi, I am trying to use RTC DS3231 but doesn’t work I use BananaPro under -Version- Kernel : Linux 3.4.103 (armv7l) Compiled : #4 SMP PREEMPT Thu Dec 18 12:55:58 CST 2014 C Library : Unknown Default C Compiler : GNU C Compiler version 4.8.4 (Ubuntu/Linaro 4.8.4-2ubuntu1~14.04.3) Distribution : Ubuntu 14.04.1 LTS

I attached RTC and did the following:

bananapi@lemaker:~$ i2cdetect -y 2 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: – -- – -- – -- – -- – -- – -- – 10: – -- – -- – -- – -- – -- – -- – -- – -- 20: – -- – -- – -- – -- – -- – -- – -- – -- 30: – -- – -- – -- – -- – -- – -- – -- – -- 40: – -- – -- – -- – -- – -- – -- – -- – -- 50: – 51 52 53 54 55 56 57 – -- – -- – -- – -- 60: – -- – -- – -- – -- 68 – -- – -- – -- – 70: 70 – 72 73 74 75 76 77

I have several I2C-units attached which are working perfectly. 0x68 is the RTC Adress which is resonding under i2cget

Then I did bananapi@lemaker:~$ echo “ds3231 0x68” | sudo tee /sys/class/i2c-adapter/i2c-2/new_device ds3231 0x68

bananapi@lemaker:~$ ls /sys/class/i2c-adapter/i2c-2 2-0068 device name power uevent delete_device i2c-dev new_device subsystem

2-0068 is the newly ceated file

bananapi@lemaker:~$ cat /sys/class/i2c-adapter/i2c-2/2-0068/name ds3231

bananapi@lemaker:~$ cat /sys/class/i2c-adapter/i2c-2/2-0068/uevent MODALIAS=i2c:ds3231

bananapi@lemaker:~$ ls /sys/class/i2c-adapter/i2c-2/2-0068 modalias name power subsystem uevent

bananapi@lemaker:~$ cat /sys/class/i2c-adapter/i2c-2/2-0068/modalias i2c:ds3231

bananapi@lemaker:~$ dmesg|grep ds3231 [ 262.288400] i2c i2c-2: new_device: Instantiated device ds3231 at 0x68

bananapi@lemaker:~$ hwclock -r hwclock: Cannot access the Hardware Clock via any known method. hwclock: Use the --debug option to see the details of our search for an access method.

bananapi@lemaker:~$ hwclock --debug hwclock von util-linux 2.20.1 hwclock: Konnte /dev/rtc nicht öffnen: Keine Berechtigung Keine brauchbare Uhrschnittstelle gefunden. hwclock: Cannot access the Hardware Clock via any known method.

/dev/rtc1 never appears

What iam missing ?