From nobody Mon Mar 07 14:48:15 2022 X-Original-To: freebsd-arm@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 771781A0BEA7 for ; Mon, 7 Mar 2022 14:48:17 +0000 (UTC) (envelope-from mail@crcomp.net) Received: from www18.qth.com (www18.qth.com [69.16.238.59]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4KC1Xw5Byfz3Qgk for ; Mon, 7 Mar 2022 14:48:16 +0000 (UTC) (envelope-from mail@crcomp.net) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crcomp.net; s=default; h=References:Subject:From:To:Date:Sender:Reply-To:Message-ID:Cc: MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=VQOghm7P/Bl4vu5i/evWTia1x4V+YDLeZp6LDolWdzM=; b=R/AFbcsS3WV2WqA4c077QmQYzF yltWhCfc3jcRcU25dqyRxe0p0rOFlOq/ay0vunBRBLNzk18m8jvDshucEqabzE7BC5lJv8SEqPaVe NdgoHmTAgtFYDu4/tk0j+Lx7g1M6EIXv92WNqvt3JgNBUGSN5LbJGy5O0Rr6codXlwJpMREQ77pUp WcGdGmls/mRX4F5geDoJkoDit698mMgUHYFF0MtnSAHPfC1Y01WNflJ0o0NQv/J+y3k1Bm0NayUw0 3A2AvtQd75h5Suii6FubgbYLXUO/GH/iZNyZSDJwbl3UVTs3upKnmfEXqzoYatb2KpYmmauE4sFLB OSBfgNJg==; Received: from [69.146.199.132] (port=31732 helo=michael2) by www18.qth.com with esmtpa (Exim 4.94.2) (envelope-from ) id 1nREel-0000sA-V5 for freebsd-arm@freebsd.org; Mon, 07 Mar 2022 08:48:16 -0600 Date: 07 Mar 2022 14:48:15 UTC To: From: Don Kuenz Subject: Re: PCF8574 I2C configuration for 14.0-CURRENT on a RPi2B References: <47C61079-AB2E-4E81-AD95-F6042477D4E8@yahoo.com> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - www18.qth.com X-AntiAbuse: Original Domain - freebsd.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - crcomp.net X-Get-Message-Sender-Via: www18.qth.com: authenticated_id: mail@crcomp.net X-Authenticated-Sender: www18.qth.com: mail@crcomp.net X-Source: X-Source-Args: X-Source-Dir: X-Rspamd-Queue-Id: 4KC1Xw5Byfz3Qgk X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dkim=pass header.d=crcomp.net header.s=default header.b="R/AFbcsS"; dmarc=none; spf=pass (mx1.freebsd.org: domain of mail@crcomp.net designates 69.16.238.59 as permitted sender) smtp.mailfrom=mail@crcomp.net X-Spamd-Result: default: False [0.40 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; R_SPF_ALLOW(-0.20)[+a]; HAS_X_SOURCE(0.00)[]; TO_DN_NONE(0.00)[]; DKIM_TRACE(0.00)[crcomp.net:+]; NEURAL_HAM_SHORT(-1.00)[-0.999]; INVALID_DATE(1.50)[]; HAS_X_ANTIABUSE(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:32244, ipnet:69.16.192.0/18, country:US]; HAS_X_AS(0.00)[mail@crcomp.net]; RCVD_IN_DNSWL_LOW(-0.10)[69.16.238.59:from]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.998]; R_DKIM_ALLOW(-0.20)[crcomp.net:s=default]; RECEIVED_SPAMHAUS_PBL(0.00)[69.146.199.132:received]; FROM_HAS_DN(0.00)[]; SH_EMAIL_DBL_DONT_QUERY_IPS(0.00)[0.0.0.51:email]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[crcomp.net]; RCPT_COUNT_ONE(0.00)[1]; MISSING_MID(2.50)[]; DBL_PROHIBIT(0.00)[0.0.0.51:email]; HAS_X_GMSV(0.00)[mail@crcomp.net]; MLMMJ_DEST(0.00)[freebsd-arm]; RCVD_COUNT_TWO(0.00)[2] X-ThisMailContainsUnwantedMimeParts: N List-Id: Porting FreeBSD to ARM processors List-Archive: https://lists.freebsd.org/archives/freebsd-arm List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-arm@freebsd.org Attempt number four to answer Mark's question in regards to the origin of config.txt content. (The em control character spewed out by "man" mangled my mail earlier.) Mark wrote: > Don wrote: >> >> and /boot/msdos/config.txt looks like this: >> >> root@generic:/boot # cat /boot/msdos/config.txt >> init_uart_clock=3000000 >> enable_uart=1 >> kernel=u-boot.bin >> kernel7=u-boot.bin >> dtoverlay=mmc > > config.txt seems fine up to here. But I've never seen > anything indicating that the following notation is > valid for config.txt files: > >> / { >> gpioiic0 { >> compatible = "i2c-gpio"; >> pinctrl-names = "default"; >> pinctrl-0 = <&pinctrl_gpioiic0>; >> scl-gpios = <&gpio2 3 GPIO_ACTIVE_HIGH>; >> sda-gpios = <&gpio3 5 GPIO_ACTIVE_HIGH>; >> status = "okay"; >> }; >> }; > > If you have a reference indicating otherwise, I'd > be interested to know what it is. # man gpioicc ------------------------------------------------------------------------ GPIOIIC(4) FreeBSD Kernel Interfaces Manual GPIOIIC(4) NAME gpioiic - GPIO I2C bit-banging device driver SYNOPSIS To compile this driver into the kernel, place the following lines in your kernel configuration file: device gpio device gpioiic device iicbb device iicbus Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5): gpioiic_load="YES" DESCRIPTION The gpioiic driver provides an IIC bit-banging interface using two GPIO pins for the SCL and SDA lines on the bus. gpioiic simulates an open collector kind of output when managing the pins on the bus, even on systems which don't directly support configuring gpio pins in that mode. The pins are never driven to the logical value of '1'. They are driven to '0' or switched to input mode (Hi-Z/tri-state), and an external pullup resistor pulls the line to the 1 state unless some other device on the bus is driving it to 0. HINTS CONFIGURATION FDT CONFIGURATION On an FDT(4) based system, such as ARM, the DTS node for gpioiic conforms to the standard bindings document i2c/i2c-gpio.yaml. The device node typically appears at the root of the device tree. The following is an example of a gpioiic node with one slave device on the IIC bus: / { gpioiic0 { compatible = "i2c-gpio"; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpioiic0>; scl-gpios = <&gpio1 5 GPIO_ACTIVE_HIGH>; sda-gpios = <&gpio7 11 GPIO_ACTIVE_HIGH>; status = "okay"; /* One slave device on the i2c bus. */ rtc@51 { compatible="nxp,pcf2127"; reg = <0x51>; status = "okay"; }; }; }; Where: compatible Should be set to "i2c-gpio". The deprecated string "gpioiic" is also accepted for backwards compatibility. scl-gpios sda-gpios These properties indicate which GPIO pins should be used for clock and data on the GPIO IIC bit-banging bus. There is no requirement that the two pins belong to the same gpio controller. pinctrl-names pinctrl-0 These properties may be required to configure the chosen pins as gpio pins, unless the pins default to that state on your system. SEE ALSO fdt(4), gpio(4), iic(4), iicbb(4), iicbus(4) ------------------------------------------------------------------------ I'll take a closer look at "man dtc" and "i2c/i2c-gpio.yaml" https://mjmwired.net/kernel/Documentation/devicetree/bindings/i2c/i2c-gpio.yaml Other replies in the thread provide me with additional food for thought for the time being. Danke, -- Don, KB7RPU, https://www.qsl.net/kb7rpu There was a young lady named Bright Whose speed was far faster than light; She set out one day In a relative way And returned on the previous night.