From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory CLEMENT Subject: Re: [PATCH 01/10] serial: mvebu-uart: initial support for Armada-3700 serial port Date: Wed, 03 Feb 2016 17:32:41 +0100 Message-ID: <87r3gt4uvq.fsf@free-electrons.com> References: <1454436468-4241-1-git-send-email-gregory.clement@free-electrons.com> <1454436468-4241-2-git-send-email-gregory.clement@free-electrons.com> <20160202182842.GD29778@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20160202182842.GD29778@leverpostej> (Mark Rutland's message of "Tue, 2 Feb 2016 18:28:42 +0000") Sender: linux-kernel-owner@vger.kernel.org To: Mark Rutland Cc: Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , arm@kernel.org, Catalin Marinas , Will Deacon , Jonathan Corbet , Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org, Tejun Heo , Hans de Goede , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Thomas Petazzoni , linux-arm-kernel@lists.infradead.org, Wilson Ding , Nadav Haklai List-Id: devicetree@vger.kernel.org Hi Mark, =20 On mar., f=C3=A9vr. 02 2016, Mark Rutland wrote= : > On Tue, Feb 02, 2016 at 07:07:39PM +0100, Gregory CLEMENT wrote: >> From: Wilson Ding >>=20 >> Armada-3700's uart is a simple serial port, which doesn't >> support. Configuring the modem control lines. The uart port has a 32 >> bytes Tx FIFO and a 64 bytes Rx FIFO >>=20 >> The uart driver implements the uart core operations. It also support= the >> system (early) console based on Armada-3700's serial port. >>=20 >> Known Issue: >>=20 >> The uart driver currently doesn't support clock programming, which m= eans >> the baud-rate stays with the default value configured by the bootloa= der >> at boot time > > To ensure that the bootloader and kernel match, it's best to place th= e > rate in the stdout-path property (as in > Documentation/devicetree/bindings/chosen.txt). > > Presumably that is what you want? It is done in patch 7. > > Is it difficutl to add clock programming? Currently there is no clock tree support before adding it I would like to be able to test it. Thanks, Gregory > >>=20 >> [gregory.clement@free-electrons.com: Rewrite many part which are too= long >> to enumerate] >>=20 >> Signed-off-by: Wilson Ding >> Signed-off-by: Nadav Haklai >> Signed-off-by: Gregory CLEMENT >> --- >> .../devicetree/bindings/tty/serial/mvebu-uart.txt | 13 + >> Documentation/kernel-parameters.txt | 6 + >> drivers/tty/serial/Kconfig | 22 + >> drivers/tty/serial/Makefile | 1 + >> drivers/tty/serial/mvebu-uart.c | 649 ++++++++++= +++++++++++ >> include/uapi/linux/serial_core.h | 3 + >> 6 files changed, 694 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/tty/serial/mve= bu-uart.txt >> create mode 100644 drivers/tty/serial/mvebu-uart.c >>=20 >> diff --git a/Documentation/devicetree/bindings/tty/serial/mvebu-uart= =2Etxt b/Documentation/devicetree/bindings/tty/serial/mvebu-uart.txt >> new file mode 100644 >> index 000000000000..6087defd9f93 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/tty/serial/mvebu-uart.txt >> @@ -0,0 +1,13 @@ >> +* Marvell UART : Non standard UART used in some of Marvell EBU SoCs= (e.g., Armada-3700) >> + >> +Required properties: >> +- compatible: "marvell,armada-3700-uart" >> +- reg: offset and length of the register set for the device. >> +- interrupts: device interrupt >> + >> +Example: >> + serial@12000 { >> + compatible =3D "marvell,armada-3700-uart"; >> + reg =3D <0x12000 0x400>; >> + interrupts =3D <43>; >> + }; > > There are no external clock inputs? > >> diff --git a/Documentation/kernel-parameters.txt b/Documentation/ker= nel-parameters.txt >> index 87d40a72f6a1..198f6bd56e84 100644 >> --- a/Documentation/kernel-parameters.txt >> +++ b/Documentation/kernel-parameters.txt >> @@ -1058,6 +1058,12 @@ bytes respectively. Such letter suffixes can = also be entirely omitted. >> A valid base address must be provided, and the serial >> port must already be setup and configured. >> =20 >> + mvebu_uart, >> + Start an early, polled-mode console on an some mvebu >> + SoC (as the Armada-3700) serial port at the specified >> + address. The serial port must already be setup and >> + configured. Options are not yet supported. >> + > > Does the the mvebu UART vary between platforms at all? > > Thanks, > Mark. --=20 Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com