From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kQtEE-000123-1L for barebox@lists.infradead.org; Fri, 09 Oct 2020 14:18:39 +0000 References: <61631575-54f8-4fe1-4a25-a806b39f2a63@pengutronix.de> From: Ahmad Fatoum Message-ID: <0fae6213-91b3-a3ae-e1b8-2c7752866b2a@pengutronix.de> Date: Fri, 9 Oct 2020 16:18:33 +0200 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: Mini UART on RaspberryPi CM3/CM3+ To: "Robert Carnecky (Neopsis)" , barebox@lists.infradead.org Hello Robert, On 10/9/20 2:30 PM, Robert Carnecky (Neopsis) wrote: >> Try adding to arch/arm/dts/bcm2837-rpi-cm3.dts: >> >> &uart1 { >> pinctrl-names = "default"; >> pinctrl-0 = <&uart1_gpio14>; >> status = "okay"; >> }; > > I extended arch/arm/dts/bcm2837-rpi-cm3.dts as advised + > additionally I set UART0 to pins 32/33. > > &uart0 { > pinctrl-names = "default"; > pinctrl-0 = <&uart0_gpio32>; > status = "okay"; > }; > > I still cannot see Barebox console on boot, however, the Barebox loader > starts in 3 seconds my kernel and I get the Linux console output on > UART1/ttyS0. Strange that this made the kernel boot now. Maybe somewhere an unclocked peripheral was being accessed before? > Now my Linux boots as expected, unfortunately without > visible Barebox console. I tried all Barebox console setting > (NONE/ALL/FIRST), same result, no Barebox console output on UART0 > or UART1. Huh, you did listen at the UART0 _before_ the RS-485 transceiver? UART0 should work, at least it apparently did when the CM3 support was added. >> If that doesn't help, use CONSOLE_ACTIVATE_ALL and listen >> on UART0 before the RS-485 transceiver and paste the >> dmesg and devinfo input you get. > > # dmesg | grep tty > [ 0.000000] Kernel command line: console=ttyS0,115200 > coherent_pool=1M snd_bcm2835.enable_compat_alsa=0 > snd_bcm2835.enable_hdmi=1 snd_bcm2835.enable_headphones=1 > 8250.nr_uarts=1 bcm2708_fb.fbwidth=656 > bcm2708_fb.fbheight=416 bcm2708_fb.fbswap=1 > smsc95xx.macaddr=B8:27:EB:C5:7D:E3 vc_mem.mem_base=0x3ec00000 > vc_mem.mem_size=0x40000000 root=/dev/mmcblk0p2 console=ttyS0,115200 > rootfstype=ext4 elevator=deadline rootwait > [ 1.289058] printk: console [ttyS0] disabled > [ 1.289175] 3f215040.serial: ttyS0 at MMIO 0x0 (irq = 53, base_baud > = 50000000) is a 16550 > [ 1.945483] printk: console [ttyS0] enabled > [ 2.432604] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 81, > base_baud = 0) is a PL011 rev2 > > # stty -F /dev/ttyAMA0 115200 > # cat /etc/inittab > /dev/ttyAMA0 <- OK I meant dmesg under barebox, if UART1 fails to output, but UART0 can be read before the transceiver. On 10/6/20 1:32 AM, Robert Carnecky (Neopsis) wrote: > I played a bit more with the config.txt settings and when I activated the flag > > uart_2ndstage=1 > > I got the barebox console! Here a snippet from the 2stage while > logging the UART lading. Oh. That would indicate that there is some sort of initialization missing. uart_2ndstage=1 initializes the UART for VideoCore use apparently and from there on, it works. > What I do not understand: how the loaded /mfs/sd/bcm2710-rpi-cm3.dtb > and the overlays > cooperate with the Barebox device tree? Does it mean we have two sets > of device tree > files? Yes. The VideoCore device tree is available in barebox as /vc.dtb, see e390c8799d91 ("ARM: rpi: save fdt that was passed from VideoCore") Hope this helps, Ahmad -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox