--- Ursprüngliche Nachricht --- Von: " " <Cedric.dewijs@xxxxxxxxxx> Datum: 05.07.2021 06:32:30 An: <cedric.dewijs@xxxxxxxxxx> Betreff: Fwd: Re: rtc_rv8803.ko does not create a /dev/rtc? --- Ursprüngliche Nachricht --- Von: Nobuhiro Iwamatsu <iwamatsu@xxxxxxxxxxx> Datum: 02.07.2021 15:08:38 An: Cedric.dewijs@xxxxxxxxxx Betreff: Re: rtc_rv8803.ko does not create a /dev/rtc? Hi, 2021年7月1日(木) 21:50 <Cedric.dewijs@xxxxxxxxxx>: > > Hi all, > > I have a raspberry pi 3B, running kernel 5.10.17. On the i2c bus, I've added a rx8900 rtc chip. I would like to use this chip, but I fail to create a /dev/rtc for it. > > I have checked the kernel version: > # uname -a > Linux raspberrypi 5.10.17-v7+ #1421 SMP Thu May 27 13:59:01 BST 2021 armv7l GNU/Linux > > I've downloaded the rtc driver for this version of the kernel from here: > https://github.com/raspberrypi/linux/blob/rpi-5.10.y/drivers/rtc/rtc-rv8803.c > > And compiled the driver with this makefile [1, see below] and installed the resulting rtc-rv8803.ko here: > > $ modinfo /usr/lib/modules/5.10.17-v7+/kernel/drivers/rtc/rtc-rv8803.ko > filename: /usr/lib/modules/5.10.17-v7+/kernel/drivers/rtc/rtc-rv8803.ko > license: GPL v2 > description: Micro Crystal RV8803 RTC driver > author: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> > srcversion: 0067552CB786360DEA9CADB > alias: i2c:rx8900 > alias: i2c:rx8803 > alias: i2c:rv8803 > alias: of:N*T*Cepson,rx8900C* > alias: of:N*T*Cepson,rx8900 > alias: of:N*T*Cepson,rx8803C* > alias: of:N*T*Cepson,rx8803 > alias: of:N*T*Cmicrocrystal,rv8803C* > alias: of:N*T*Cmicrocrystal,rv8803 > depends: > name: rtc_rv8803 > vermagic: 5.10.17-v7+ SMP mod_unload modversions ARMv7 p2v8 > > Next I do the following steps to load the module: > # modprobe i2c:rx8900 > [ 130.591843] rtc_rv8803: loading out-of-tree module taints kernel. This is not necessary if the module is installed correctly. The module will be loaded when you write to '/sys/class/ i2c-adapter/i2c-1/new_device' below. > > The module is loaded: > # lsmod > Module Size Used by > rtc_rv8803 16384 0 > > Next I bind the driver to the i2c address 0x32: > # echo i2c:rx8900 0x32 > /sys/class/i2c-adapter/i2c-1/new_device I think ' i2c' is unnecessary. Please check with following: echo rx8900 0x32 > /sys/class/i2c-adapter/i2c-1/new_device > [ 176.871589] i2c i2c-1: new_device: Instantiated device i2c:rx8900 at 0x32 > > This does not give me a /dev/rtc device: > # ls /dev/rtc* > ls: cannot access '/dev/rtc*': No such file or directory > > The rtc is detected at address 0x32, but it's not claimed by any driver (that would have been indicated by UU instead of 32). > # i2cdetect -y 1 > 0 1 2 3 4 5 6 7 8 9 a b c d e f > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 20: -- -- -- -- -- -- -- -- -- 29 -- -- -- -- -- -- > 30: -- -- 32 -- -- -- -- -- -- -- -- -- -- -- -- -- > 40: -- -- -- -- -- -- -- -- -- 49 4a -- -- -- -- -- > 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- -- > 70: -- -- -- -- -- -- -- -- > > What did I miss? > > Kind regards, > Cedric Best regards, Nobuhiro Hi, it worked: pi@raspberrypi:~ $ sudo -i root@raspberrypi:~# echo rx8900 0x32 > /sys/class/i2c-adapter/i2c-1/new_device Jul 1 17:17:32 raspberrypi kernel: i2c i2c-1: new_device: Instantiated device rx8900 at 0x32 Jul 1 17:17:32 raspberrypi kernel: rtc_rv8803: loading out-of-tree module taints kernel. Jul 1 17:17:32 raspberrypi kernel: rtc-rv8803 1-0032: Voltage low, temperature compensation stopped. Jul 1 17:17:32 raspberrypi kernel: rtc-rv8803 1-0032: Voltage low, data loss detected. Jul 1 17:17:32 raspberrypi kernel: rtc-rv8803 1-0032: An alarm maybe have been missed. Jul 1 17:17:32 raspberrypi kernel: rtc-rv8803 1-0032: Voltage low, data is invalid. Jul 1 17:17:32 raspberrypi kernel: rtc-rv8803 1-0032: registered as rtc0 Jul 1 17:21:02 raspberrypi dhcpcd[430]: wlan0: hardware address 00:00:00:00:00:00 claims 10.93.128.58 root@raspberrypi:~# ls -l /dev/rtc0 crw------- 1 root root 252, 0 Jul 1 17:17 /dev/rtc0 root@raspberrypi:~# i2cdetect -y 1 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- 29 -- -- -- -- -- -- 30: -- -- UU -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- 49 4a -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- root@raspberrypi:~# hwclock -w root@raspberrypi:~# hwclock -r 2021-07-01 17:29:37.223549+02:00 root@raspberrypi:~# hwclock -r 2021-07-01 17:29:49.788067+02:00 Thank you, Cedric ________________________________________________________ Ihr Recht auf Privatsphäre. Schützen Sie Ihre Daten und wechseln jetzt zu eclipso Mail & Cloud - https://www.eclipso.de
