From mboxrd@z Thu Jan 1 00:00:00 1970 From: xow@google.com (Xo Wang) Date: Thu, 5 May 2016 23:11:53 +0000 (UTC) Subject: [PATCH v2 09/11] arm/dst: Add Aspeed ast2500 device tree References: <1461225849-28074-1-git-send-email-joel@jms.id.au> <1461225849-28074-10-git-send-email-joel@jms.id.au> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Joel Stanley jms.id.au> writes: > +/ { > + model = "AST2500 EVB"; > + compatible = "aspeed,ast2500"; > + > + chosen { > + stdout-path = &uart5; > + bootargs = "console=ttyS4,115200"; > + }; > + > + memory { > + reg = < 0x80000000 0x10000000 >; The AST2500 EVB has an SK Hynix H5AN4G6NMFR 4Gb part, so this should be 0x20000000 for size. > + uart1: serial 1e783000 { > + compatible = "ns16550a"; > + reg = <0x1e783000 0x1000>; > + reg-shift = <2>; > + interrupts = <9>; > + clock-frequency = <1843200>; The AST2500 datasheet 39.3.1 states the input clock to their 16550 IP is 24 MHz. Their u-boot code also has #define CONFIG_SYS_NS16550_CLK 24000000. I suspect we hit a path in the serial/8250 driver that doesn't change the divisor from what u-boot set, which is why this has worked. Thanks for the porting work! cheers //xo