From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-lb0-x234.google.com ([2a00:1450:4010:c04::234]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WzBgc-00078e-9u for barebox@lists.infradead.org; Mon, 23 Jun 2014 21:21:58 +0000 Received: by mail-lb0-f180.google.com with SMTP id w7so5241071lbi.25 for ; Mon, 23 Jun 2014 14:21:41 -0700 (PDT) From: Antony Pavlov Date: Tue, 24 Jun 2014 01:21:12 +0400 Message-Id: <1403558473-26199-7-git-send-email-antonynpavlov@gmail.com> In-Reply-To: <1403558473-26199-1-git-send-email-antonynpavlov@gmail.com> References: <1403558473-26199-1-git-send-email-antonynpavlov@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 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: [PATCH 6/7] MIPS: dts: qemu-malta.dts: use i2c-gpio for accessing CBUS FPGA I2C bus To: barebox@lists.infradead.org Also we can enable m24c02 eeprom chip in dts-file e.g. &i2c0 { status = "okay"; eeprom: m24c02@50 { compatible = "spd"; reg = <0x50>; }; }; Alas! qemu mips malta spd m24c02 eeprom chip emulation is not perfect: the block read operation does not work properly. Here is an example. If we read eeprom content byte-by-byte then there is no problem: barebox:/ for i in 0x08 0x09 0x0a 0x0b 0x0c 0x0d 0x0e 0x0f ; > do i2c_read -b 0 -a 0x50 -r $i -c 1 ; done 0x01 0x75 0x54 0x00 0x82 0x08 0x00 0x01 Compare this output with content of qemu.git/hw/mips/mips_malta.c: static eeprom24c0x_t spd_eeprom = { .contents = { ... /* 00000008: */ 0x01,0x75,0x54,0x00,0x82,0x08,0x00,0x01, But if we read several bytes at once the we have data corruption: barebox:/ i2c_read -b 0 -a 0x50 -r 0x8 -c 8 0x01 0xff 0xff 0xff 0xff 0xff 0xff 0xff Signed-off-by: Antony Pavlov --- arch/mips/dts/qemu-malta.dts | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/mips/dts/qemu-malta.dts b/arch/mips/dts/qemu-malta.dts index 204007d..cc1c960 100644 --- a/arch/mips/dts/qemu-malta.dts +++ b/arch/mips/dts/qemu-malta.dts @@ -32,6 +32,18 @@ #gpio-cells = <2>; }; + i2c0: i2c0 { + compatible = "i2c-gpio"; + gpios = <&gpio 0 0 /* sda */ + &gpio 1 0 /* scl */ + >; + i2c-gpio,sda-open-drain; + i2c-gpio,scl-open-drain; + #address-cells = <1>; + #size-cells = <0>; + status = "disabled"; + }; + uart2: serial@bf000900 { compatible = "ns16550a"; reg = <0xbf000900 0x40>; @@ -58,3 +70,7 @@ }; }; }; + +&i2c0 { + status = "okay"; +}; -- 1.9.2 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox