From mboxrd@z Thu Jan 1 00:00:00 1970 From: yuanzhichang@hisilicon.com (zhichang.yuan) Date: Wed, 14 Sep 2016 19:48:49 +0800 Subject: [PATCH V2 3/4] ARM64 LPC: support serial based on low-pin-count In-Reply-To: <2531252.L41vzyMSKX@wuerfel> References: <1473255233-154297-1-git-send-email-yuanzhichang@hisilicon.com> <5345060.9D0B4ujt5e@wuerfel> <57D1349D.8070905@gmail.com> <2531252.L41vzyMSKX@wuerfel> Message-ID: <57D93921.50303@hisilicon.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2016/9/8 17:58, Arnd Bergmann wrote: > On Thursday, September 8, 2016 5:51:25 PM CEST zhichang wrote: >> On 2016?09?07? 22:50, Arnd Bergmann wrote: >>> On Wednesday, September 7, 2016 9:33:52 PM CEST Zhichang Yuan wrote: >>>> From: "zhichang.yuan" >>>> >>>> On Hip06 platform, a 16550 compatible UART is connected to low-pin-count and >>>> controlled through the LPC I/O cycles. This patch drives the UART port with >>>> the specific serial in/out function pair based on the indirect-IO mechanism >>>> introduced by Hip06 LPC driver. >>>> >>>> Signed-off-by: zhichang.yuan >>> >>> Any reason this cannot just use the regular drivers/tty/serial/8250/8250_of.c >>> driver? >> I think two reasons for that: >> 1. 8250_of.c is only for devicetree, but we need to support ACPI device too; > > ACPI has its own way of describing serial ports, use that instead. Could you give me some info about ACPI serial ports? I found there is _CRS specific for serial, but it seems no serial driver use that. Thanks! Zhichang > >> 2. It seems UPIO_PORT is not supported there. > > Should be easy enough to add. > > Arnd > > . >