From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleksandr Tyshchenko Subject: Re: [PATCH v1] xen/serial: Return actual bytes stored in TX FIFO for OMAP Date: Tue, 27 Oct 2015 13:33:26 +0200 Message-ID: References: <1445942183-1512-1-git-send-email-oleksandr.tyshchenko@globallogic.com> <562F652102000078000AF061@prv-mh.provo.novell.com> <562F57F9.1020805@citrix.com> <562F689C02000078000AF089@prv-mh.provo.novell.com> <562F5CCC.6080308@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <562F5CCC.6080308@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: "xen-devel@lists.xen.org" , Tim Deegan , Ian Campbell , Jan Beulich , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org Hi, all. Although OMAP and 8250 compatible UARTs have a lot of common, they differs at least in configuration steps since OMAP UART has such thing as "register access mode", also OMAP UART has additional features and as a result a subset of additional registers. On Tue, Oct 27, 2015 at 1:15 PM, Julien Grall wrote: > On 27/10/15 11:05, Jan Beulich wrote: >>>>> On 27.10.15 at 11:54, wrote: >>> On 27/10/15 10:50, Jan Beulich wrote: >>>>>>> On 27.10.15 at 11:36, wrote: >>>>> --- a/xen/include/xen/8250-uart.h >>>>> +++ b/xen/include/xen/8250-uart.h >>>>> @@ -143,6 +143,15 @@ >>>>> /* Supplementary control register */ >>>>> #define UART_OMAP_SCR 0x10 >>>> >>>> I think this one is already misplaced here (as is the one in the context >>>> below the change). >>> >>> I don't think so, the omap UART is based on the 8250 and share some >>> common registers. >> >> Well, if it's that way then the patch is fine, but I then question why >> we have a separate omap-uart.c. > > I've got no clue, the omap is a superset of the 8250 and actually we > already use the 8250 low-level serial for those platforms. > > Linux is also having a separate driver for the OMAP UART. Oleksandr, is > there any fundamental difference between the OMAP and ns16550 driver? > > Regards, > > -- > Julien Grall -- Oleksandr Tyshchenko | Embedded Dev GlobalLogic www.globallogic.com