From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philip Elcan Subject: Re: [PATCH 10/10] drivers: PL011: add support for the ARM SBSA generic UART Date: Tue, 17 Feb 2015 10:55:35 -0500 Message-ID: <54E36477.3050406@codeaurora.org> References: <1421428986-11300-1-git-send-email-andre.przywara@arm.com> <1421428986-11300-11-git-send-email-andre.przywara@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1421428986-11300-11-git-send-email-andre.przywara@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Andre Przywara , linux@arm.linux.org.uk, gregkh@linuxfoundation.org, jslaby@suse.cz Cc: Mark Rutland , rob.herring@linaro.org, arnd@arndb.de, linux-serial@vger.kernel.org, Dave Martin , linux-arm-kernel@lists.infradead.org List-Id: linux-serial@vger.kernel.org On 01/16/2015 12:23 PM, Andre Przywara wrote: > The ARM Server Base System Architecture[1] document describes a > generic UART which is a subset of the PL011 UART. > It lacks DMA support, baud rate control and modem status line > control, among other things. > The idea is to move the UART initialization and setup into the > firmware (which does this job today already) and let the kernel just > use the UART for sending and receiving characters. > We use the recent refactoring the build a new struct uart_ops > variable which points to some new functions avoiding access to the > missing registers. We reuse as much existing PL011 code as possible. > > In contrast to the PL011 the SBSA UART does not define any AMBA or > PrimeCell relations, so we go a pretty generic probe function > which only uses platform device functions. > A DT binding is provided, but other systems can easily attach to it, > too (hint, hint!). > > Signed-off-by: Andre Przywara > --- Andre, I'm a little late to address this patchset, but the SBSA defines all the Generic UART registers 32-bit wide. However, the amba-pl011 driver uses 16-bit accessors. How will you be handling that? Can the ARM PL011 hardware handle 32-bit access? Philip -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project