Thread (25 messages) 25 messages, 6 authors, 2016-03-05

Re: [PATCH v10] serial: support for 16550A serial ports on LP-8x4x

From: Rob Herring <robh@kernel.org>
Date: 2016-03-05 04:26:48
Also in: linux-serial, lkml

On Wed, Mar 02, 2016 at 12:25:35AM +0300, Sergei Ianovich wrote:
The patch adds support for 3 additional LP-8x4x built-in serial
ports.

The device can also host up to 8 extension cards with 4 serial ports
on each card for a total of 35 ports. However, I don't have
the hardware to test extension cards, so they are not supported, yet.
That's a lot of serial ports...

[...]
quoted hunk ↗ jump to hunk
diff --git a/Documentation/devicetree/bindings/serial/icpdas-lp8841-uart.txt b/Documentation/devicetree/bindings/serial/icpdas-lp8841-uart.txt
new file mode 100644
index 0000000..d6acd22
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/icpdas-lp8841-uart.txt
@@ -0,0 +1,41 @@
+* UART ports on ICP DAS LP-8841
+
+LP-8441, LP-8141 and LP-8041 are fully compatible.
+
+ICP DAS LP-8841 contains three additional serial ports interfaced via
+Analog Devices ADM213EA chips in addition to 3 serial ports on PXA CPU.
+
+The chips themselves are standard, they would work with 8250_core if
Describe in h/w terms how they are different, not what Linux driver 
won't work.
+properly connected. However, they are not connected normally. Al least
s/Al/At/
+some of their config pins are wired to a different address region. So
+the driver is board-specific.
+
+Required properties:
+- compatible : should be "icpdas,uart-lp8841"
+
+- reg : should provide 16 byte man IO memory region and 1 byte region for
What is "man IO"?
+	termios
termios is a Linux term.
+
+- interrupts : should provide interrupt
Perhaps you should include other properties standard for 8250 such as 
access size or shift. Possibly if the non-standard bits are already 
configured, the UART could be used for earlycon?
+
+Optional property:
+- interrupt-parent : should provide a link to interrupt controller either
+		     explicitly or implicitly from a parent node
+
+Examples (from pxa27x-lp8x4x.dts):
+
+		serial@9050 {
+			compatible = "icpdas,uart-lp8841";
+			reg = <0x9050 0x10
+			       0x9030 0x02>;
+			interrupts = <13>;
+			status = "okay";
+		};
+
+		serial@9060 {
+			compatible = "icpdas,uart-lp8841";
+			reg = <0x9060 0x10
+			       0x9032 0x02>;
+			interrupts = <14>;
+			status = "okay";
+		};
[...]
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diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 3b5cf9c..68640c1 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -394,3 +394,17 @@ config SERIAL_8250_PXA
 	help
 	  If you have a machine based on an Intel XScale PXA2xx CPU you
 	  can enable its onboard serial ports by enabling this option.
+
+	  If you choose M here, the module name will be 8250_pxa.
+
+config SERIAL_8250_LP8841
+	tristate "Support 16550A ports on ICP DAS LP-8841"
+	depends on SERIAL_8250 && MACH_PXA27X_DT
+	select LP8841_IRQ
Generally, drivers don't select their interrupt controller.
+	help
+	  In addition to serial ports on PXA270 SoC, LP-8841 has 1 dual
+	  RS232/RS485 port, 1 RS485 port and 1 RS232 port.
+
+	  Say N here, unless you plan to run this kernel on a LP-8841 system.
+
+	  If you choose M here, the module name will be 8250_lp8841.
quoted hunk ↗ jump to hunk
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index d1e2f2d..10b4bf0 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_SERIAL_8250_ACCENT)	+= 8250_accent.o
 obj-$(CONFIG_SERIAL_8250_BOCA)		+= 8250_boca.o
 obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554)	+= 8250_exar_st16c554.o
 obj-$(CONFIG_SERIAL_8250_HUB6)		+= 8250_hub6.o
+obj-$(CONFIG_SERIAL_8250_LP8X4X)	+= 8250_lp8x4x.o
This should be dropped.
quoted hunk ↗ jump to hunk
 obj-$(CONFIG_SERIAL_8250_FSL)		+= 8250_fsl.o
 obj-$(CONFIG_SERIAL_8250_DW)		+= 8250_dw.o
 obj-$(CONFIG_SERIAL_8250_EM)		+= 8250_em.o
@@ -30,5 +31,6 @@ obj-$(CONFIG_SERIAL_8250_INGENIC)	+= 8250_ingenic.o
 obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
 obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o
+obj-$(CONFIG_SERIAL_8250_LP8841)	+= 8250_lp8841.o
This should be in alphabetical order. OF_PLATFORM is not for legacy 
reasons I think.
 
 CFLAGS_8250_ingenic.o += -I$(srctree)/scripts/dtc/libfdt
-- 
2.7.0
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