Add Spreadtrum Sharkl Platform support

The file of-serial.txt was only for 8250 compatible UART implementations, so renamed it to 8250.txt to avoid confusing other persons.

Signed-off-by Chunyan Zhang <[email protected]>

---
 Documentation/devicetree/bindings/serial/8250.txt  |   50 ++++++++++++++++++++
 .../devicetree/bindings/serial/of-serial.txt       |   50 --------------------
 2 files changed, 50 insertions(+), 50 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/serial/8250.txt
 delete mode 100644 Documentation/devicetree/bindings/serial/of-serial.txt

Documentation/devicetree/bindings/serial/8250.txt new file +50 -0

new file mode 100644
index 0000000..7705477
@@ -0,0 +1,50 @@
+* UART (Universal Asynchronous Receiver/Transmitter)
+
+Required properties:
+- compatible : one of:
+	- "ns8250"
+	- "ns16450"
+	- "ns16550a"
+	- "ns16550"
+	- "ns16750"
+	- "ns16850"
+	- "nvidia,tegra20-uart"
+	- "nxp,lpc3220-uart"
+	- "ibm,qpace-nwp-serial"
+	- "altr,16550-FIFO32"
+	- "altr,16550-FIFO64"
+	- "altr,16550-FIFO128"
+	- "serial" if the port type is unknown.
+- reg : offset and length of the register set for the device.
+- interrupts : should contain uart interrupt.
+- clock-frequency : the input clock frequency for the UART
+	 or
+  clocks phandle to refer to the clk used as per Documentation/devicetree
+  /bindings/clock/clock-bindings.txt
+
+Optional properties:
+- current-speed : the current active speed of the UART.
+- reg-offset : offset to apply to the mapbase from the start of the registers.
+- reg-shift : quantity to shift the register offsets by.
+- reg-io-width : the size (in bytes) of the IO accesses that should be
+  performed on the device.  There are some systems that require 32-bit
+  accesses to the UART (e.g. TI davinci).
+- used-by-rtas : set to indicate that the port is in use by the OpenFirmware
+  RTAS and should not be registered.
+- no-loopback-test: set to indicate that the port does not implements loopback
+  test mode
+- fifo-size: the fifo size of the UART.
+- auto-flow-control: one way to enable automatic flow control support. The
+  driver is allowed to detect support for the capability even without this
+  property.
+- has-hw-flow-control: the hardware has flow control capability.
+
+Example:
+
+	uart at 80230000 {
+		compatible = "ns8250";
+		reg = <0x80230000 0x100>;
+		clock-frequency = <3686400>;
+		interrupts = <10>;
+		reg-shift = <2>;
+	};

Documentation/devicetree/bindings/serial/of-serial.txt deleted +0 -50

deleted file mode 100644
index 7705477..0000000
@@ -1,50 +0,0 @@
-* UART (Universal Asynchronous Receiver/Transmitter)
-
-Required properties:
-- compatible : one of:
-	- "ns8250"
-	- "ns16450"
-	- "ns16550a"
-	- "ns16550"
-	- "ns16750"
-	- "ns16850"
-	- "nvidia,tegra20-uart"
-	- "nxp,lpc3220-uart"
-	- "ibm,qpace-nwp-serial"
-	- "altr,16550-FIFO32"
-	- "altr,16550-FIFO64"
-	- "altr,16550-FIFO128"
-	- "serial" if the port type is unknown.
-- reg : offset and length of the register set for the device.
-- interrupts : should contain uart interrupt.
-- clock-frequency : the input clock frequency for the UART
-	 or
-  clocks phandle to refer to the clk used as per Documentation/devicetree
-  /bindings/clock/clock-bindings.txt
-
-Optional properties:
-- current-speed : the current active speed of the UART.
-- reg-offset : offset to apply to the mapbase from the start of the registers.
-- reg-shift : quantity to shift the register offsets by.
-- reg-io-width : the size (in bytes) of the IO accesses that should be
-  performed on the device.  There are some systems that require 32-bit
-  accesses to the UART (e.g. TI davinci).
-- used-by-rtas : set to indicate that the port is in use by the OpenFirmware
-  RTAS and should not be registered.
-- no-loopback-test: set to indicate that the port does not implements loopback
-  test mode
-- fifo-size: the fifo size of the UART.
-- auto-flow-control: one way to enable automatic flow control support. The
-  driver is allowed to detect support for the capability even without this
-  property.
-- has-hw-flow-control: the hardware has flow control capability.
-
-Example:
-
-	uart at 80230000 {
-		compatible = "ns8250";
-		reg = <0x80230000 0x100>;
-		clock-frequency = <3686400>;
-		interrupts = <10>;
-		reg-shift = <2>;
-	};

Signature · 1 line

1.7.9.5

The file of-serial.txt was only for 8250 compatible UART implementations, so renamed it to 8250.txt to avoid confusing other persons.

Signed-off-by Chunyan Zhang <[email protected]>

---
 Documentation/devicetree/bindings/serial/8250.txt  |   50 ++++++++++++++++++++
 .../devicetree/bindings/serial/of-serial.txt       |   50 --------------------
 2 files changed, 50 insertions(+), 50 deletions(-)

Adds Spreadtrum's prefix "sprd" to vendor-prefixes file. Adds the devicetree binding documentation for Spreadtrum's serial and Sharkl3 SoC based on the Sharkl Platform which is the 64-bit SoC Platform of Spreadtrum.

Signed-off-by Chunyan Zhang <[email protected]>

---
 Documentation/devicetree/bindings/arm/sprd.txt     |   11 +++++++++++
 .../devicetree/bindings/serial/sprd-serial.txt     |    6 ++++++
 .../devicetree/bindings/vendor-prefixes.txt        |    1 +
 3 files changed, 18 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/sprd.txt
 create mode 100644 Documentation/devicetree/bindings/serial/sprd-serial.txt

Documentation/devicetree/bindings/arm/sprd.txt new file +11 -0

new file mode 100644
index 0000000..40b40d6
@@ -0,0 +1,11 @@
+Spreadtrum Sharkl Platforms Device Tree Bindings
+----------------------------------------------------
+
+Sharkl is a Spreadtrum's SoC Platform which is based
+on ARM 64-bit processor.
+
+Sharkl3 FPGA board with Sharkl3 SoC based on the
+Sharkl Platform shall have the following properties.
+
+Required root node properties:
+        - compatible = "sprd,sharkl3-fpga", "sprd,sharkl3";

Documentation/devicetree/bindings/serial/sprd-serial.txt new file +0 -0

new file mode 100644
index 0000000..c97b0a6

Adds Spreadtrum's prefix "sprd" to vendor-prefixes file. Adds the devicetree binding documentation for Spreadtrum's serial and Sharkl3 SoC based on the Sharkl Platform which is the 64-bit SoC Platform of Spreadtrum.

Signed-off-by Chunyan Zhang <[email protected]>

From: Zhizhou Zhang <[email protected]>

Adds the device tree support for Spreadtrum Sharkl3 SoC which is based on Sharkl platform.

Sharkl platform contains the common nodes of Spreadtrum's arm64-based SoCs.

Signed-off-by Zhizhou Zhang <[email protected]>

Signed-off-by Chunyan Zhang <[email protected]>

---
 arch/arm64/boot/dts/Makefile              |    1 +
 arch/arm64/boot/dts/sprd-sharkl.dtsi      |   33 ++++++++++++++
 arch/arm64/boot/dts/sprd-sharkl3-fpga.dts |   41 +++++++++++++++++
 arch/arm64/boot/dts/sprd-sharkl3.dtsi     |   69 +++++++++++++++++++++++++++++
 4 files changed, 144 insertions(+)
 create mode 100644 arch/arm64/boot/dts/sprd-sharkl.dtsi
 create mode 100644 arch/arm64/boot/dts/sprd-sharkl3-fpga.dts
 create mode 100644 arch/arm64/boot/dts/sprd-sharkl3.dtsi

arch/arm64/boot/dts/Makefile +1 -0

index c52bdb0..0030e44 100644
@@ -1,3 +1,4 @@
+dtb-$(CONFIG_ARCH_SHARKL) += sprd-sharkl3-fpga.dtb
 dtb-$(CONFIG_ARCH_VEXPRESS) += rtsm_ve-aemv8a.dtb foundation-v8.dtb
 dtb-$(CONFIG_ARCH_XGENE) += apm-mustang.dtb
 

arch/arm64/boot/dts/sprd-sharkl.dtsi new file +33 -0

new file mode 100644
index 0000000..26a28c3
@@ -0,0 +1,33 @@
+/*
+ * dtsi file for Spreadtrum(sprd) Sharkl Platform based on AArch64.
+ *
+ * Copyright (C) 2014,  Spreadtrum Communications Inc.
+ *
+ * Sharkl Platform is the base of Spreadtrum arm64 SoCs whose common
+ * nodes are listed in this file.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+/ {
+	interrupt-parent = <&gic>;
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	uart0: serial at 70000000 {
+		compatible = "sprd,serial";
+		reg = <0 0x70000000 0 0x100>;
+		interrupts = <0 2 0xf04>;
+		status = "disabled";
+	};
+
+	uart1: serial at 70100000 {
+		compatible = "sprd,serial";
+		reg = <0 0x70100000 0 0x100>;
+		interrupts = <0 3 0xf04>;
+		status = "disabled";
+	};
+};

arch/arm64/boot/dts/sprd-sharkl3-fpga.dts new file +8 -0

new file mode 100644
index 0000000..faa0a2e
@@ -0,0 +1,41 @@
+/*
+ * DTS file for Spreadtrum(sprd) Sharkl3 FPGA board based on
+ * the Sharkl Platform.
+ *
+ * Copyright (C) 2014,  Spreadtrum Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as

arch/arm64/boot/dts/sprd-sharkl3-fpga.dts new file +23 -0

+
+	compatible = "sprd,sharkl3-fpga", "sprd,sharkl3";
+
+	aliases {
+	};
+
+	memory at 80000000 {
+		device_type = "memory";
+		reg = <0 0x80000000 0 0x20000000>;
+	};
+
+	chosen {
+		stdout-path = &uart0;
+	};
+
+	uart0: serial at 70000000 {
+		status = "okay";
+	};
+
+	uart1: serial at 70100000 {
+		status = "okay";
+	};
+};

arch/arm64/boot/dts/sprd-sharkl3.dtsi new file +15 -0

new file mode 100644
index 0000000..0ab4a94
@@ -0,0 +1,69 @@
+/*
+ * dtsi file for Spreadtrum(sprd) Sharkl3 SoC based on the Sharkl Platform.
+ *
+ * Copyright (C) 2014,  Spreadtrum Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include "sprd-sharkl.dtsi"
+
+/ {
+	compatible = "sprd,sharkl3";

arch/arm64/boot/dts/sprd-sharkl3.dtsi new file +17 -0

+			reg = <0x0 0x0>;
+			enable-method = "psci";
+		};
+		cpu at 1 {
+			device_type = "cpu";
+			compatible = "arm,armv8";
+			reg = <0x0 0x1>;
+			enable-method = "psci";
+		};
+		cpu at 2 {
+			device_type = "cpu";
+			compatible = "arm,armv8";
+			reg = <0x0 0x2>;
+			enable-method = "psci";
+		};
+		cpu at 3 {
+			device_type = "cpu";

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

Signed-off-by Chunyan Zhang <[email protected]>

---
 drivers/tty/serial/Kconfig       |   24 ++++++++++++++
 drivers/tty/serial/Makefile      |    1 +
 drivers/tty/serial/sprd-serial.c |   64 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+)
 create mode 100644 drivers/tty/serial/sprd-serial.c

drivers/tty/serial/Kconfig +1 -0

index 26cec64..33b8f90 100644
@@ -113,6 +113,30 @@ config SERIAL_SB1250_DUART_CONSOLE
 
 	  If unsure, say Y.
 
+config SERIAL_SPRD

drivers/tty/serial/Kconfig +2 -0

+
+
 config SERIAL_ATMEL
 	bool "AT91 / AT32 on-chip serial port support"
 	depends on ARCH_AT91 || AVR32

drivers/tty/serial/Makefile +1 -0

index 0080cc3..b16e0d4 100644
@@ -92,6 +92,7 @@ obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o
 obj-$(CONFIG_SERIAL_RP2)	+= rp2.o
 obj-$(CONFIG_SERIAL_FSL_LPUART)	+= fsl_lpuart.o
 obj-$(CONFIG_SERIAL_MEN_Z135)	+= men_z135_uart.o
+obj-$(CONFIG_SERIAL_SPRD) += sprd-serial.o
 
 # GPIOLIB helpers for modem control lines
 obj-$(CONFIG_SERIAL_MCTRL_GPIO)	+= serial_mctrl_gpio.o

drivers/tty/serial/sprd-serial.c new file +64 -0

new file mode 100644
index 0000000..9ae594f
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2012 Spreadtrum Communications Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <linux/of.h>
+
+/*offset*/
+#define UART_TXD	0x0000
+#define UART_RXD	0x0004
+#define UART_STS0	0x0008
+#define UART_STS1	0x000C
+#define UART_IEN	0x0010
+#define UART_ICLR	0x0014
+#define UART_CTL0	0x0018
+#define UART_CTL1	0x001C
+#define UART_CTL2	0x0020
+#define UART_CLKD0	0x0024
+#define UART_CLKD1	0x0028
+#define UART_STS2	0x002C
+
+/*line status */
+#define UART_LSR_TX_OVER	(0x1<<15)
+
+static void serial_sprd_putc(struct uart_port *port, int c)
+{
+	while (!(readl(port->membase + UART_STS0) & UART_LSR_TX_OVER))
+		;
+	writeb(c, port->membase + UART_TXD);
+}
+
+static void serial_sprd_early_write(struct console *con, const char *s,
+				    unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, serial_sprd_putc);
+}
+
+static int __init serial_sprd_early_console_setup(
+				struct earlycon_device *device,
+				const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = serial_sprd_early_write;
+	return 0;
+}
+EARLYCON_DECLARE(serial_sprd, serial_sprd_early_console_setup);
+OF_EARLYCON_DECLARE(serial_sprd, "sprd,serial",
+		    serial_sprd_early_console_setup);

Signature · 1 line

1.7.9.5

Quoted 19 lines

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

Signed-off-by Chunyan Zhang <[email protected]>

---
 drivers/tty/serial/Kconfig       |   24 ++++++++++++++
 drivers/tty/serial/Makefile      |    1 +
 drivers/tty/serial/sprd-serial.c |   64 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+)
 create mode 100644 drivers/tty/serial/sprd-serial.c

drivers/tty/serial/Kconfig +0 -0

index 26cec64..33b8f90 100644
@@ -113,6 +113,30 @@ config SERIAL_SB1250_DUART_CONSOLE
 
        If unsure, say Y.
 

drivers/tty/serial/Kconfig config SERIAL_SB1250_DUART_CONSOLE · line 126

Quoted 11 lines

drivers/tty/serial/Kconfig +11 -0

+config SERIAL_SPRD
+     tristate "Support for SPRD serial"
+     depends on ARM || ARM64
+     select SERIAL_CORE
+     help
+          This enables the driver for the Spreadtrum's serial.
+
+config SERIAL_SPRD_NR
+        int "Maximum number of sprd serial ports"
+        depends on SERIAL_SPRD
+        default "4"

This is not used below.

drivers/tty/serial/Kconfig config SERIAL_SB1250_DUART_CONSOLE · line 137

Quoted 11 lines

drivers/tty/serial/Kconfig +11 -0

+
+config SERIAL_SPRD_CONSOLE
+        bool "SPRD UART console support"
+        depends on SERIAL_SPRD=y
+        select SERIAL_CORE_CONSOLE
+     select SERIAL_EARLYCON
+        help
+       Support for early debug console using Spreadtrum's serial. This enables
+       the console before standard serial driver is probed. This is enabled
+       with "earlycon=serial_sprd" on the kernel command line. The console is
+       enabled when early_param is processed.

There only appears to be an earlycon driver, and not "standard serial driver".

What happens after earlycon?

Surely there should be a real driver to take ownership of the UART?

As far as I can see it won't be possible to boot your platform to a prompt, because earlycon will have gone before that.

Thanks,
Mark.

2014-10-17 21:03 GMT+08:00 Mark Rutland <[email protected]>:

Quoted 20 lines · Chunyan Zhang

Quoted 19 lines

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

Signed-off-by Chunyan Zhang <[email protected]>

---
 drivers/tty/serial/Kconfig       |   24 ++++++++++++++
 drivers/tty/serial/Makefile      |    1 +
 drivers/tty/serial/sprd-serial.c |   64 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+)
 create mode 100644 drivers/tty/serial/sprd-serial.c

drivers/tty/serial/Kconfig +0 -0

index 26cec64..33b8f90 100644
@@ -113,6 +113,30 @@ config SERIAL_SB1250_DUART_CONSOLE
 
        If unsure, say Y.
 

Quoted 14 lines

drivers/tty/serial/Kconfig config SERIAL_SB1250_DUART_CONSOLE · line 126

Quoted 11 lines

drivers/tty/serial/Kconfig +11 -0

+config SERIAL_SPRD
+     tristate "Support for SPRD serial"
+     depends on ARM || ARM64
+     select SERIAL_CORE
+     help
+          This enables the driver for the Spreadtrum's serial.
+
+config SERIAL_SPRD_NR
+        int "Maximum number of sprd serial ports"
+        depends on SERIAL_SPRD
+        default "4"

This is not used below.

Ok, I'll remove it in v3.

Quoted 17 lines

drivers/tty/serial/Kconfig config SERIAL_SB1250_DUART_CONSOLE · line 137

Quoted 11 lines

drivers/tty/serial/Kconfig +11 -0

+
+config SERIAL_SPRD_CONSOLE
+        bool "SPRD UART console support"
+        depends on SERIAL_SPRD=y
+        select SERIAL_CORE_CONSOLE
+     select SERIAL_EARLYCON
+        help
+       Support for early debug console using Spreadtrum's serial. This enables
+       the console before standard serial driver is probed. This is enabled
+       with "earlycon=serial_sprd" on the kernel command line. The console is
+       enabled when early_param is processed.

There only appears to be an earlycon driver, and not "standard serial driver".

What happens after earlycon?

Quoted 8 lines

Surely there should be a real driver to take ownership of the UART?

As far as I can see it won't be possible to boot your platform to a prompt, because earlycon will have gone before that.

Thanks,
Mark.

We are planed to add standard serial driver after this patch-set is approved. In the first patch we contribute to the upstream, I'd like to add architecture related code of
Spreadtrum's Sharkl, and then we will add more functions about Sharkl3 SoC step by step.

Quoted 63 lines

2014-10-17 21:03 GMT+08:00 Mark Rutland <[email protected]>:

Quoted 20 lines · Chunyan Zhang

Quoted 19 lines

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

Signed-off-by Chunyan Zhang <[email protected]>

---
 drivers/tty/serial/Kconfig       |   24 ++++++++++++++
 drivers/tty/serial/Makefile      |    1 +
 drivers/tty/serial/sprd-serial.c |   64 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+)
 create mode 100644 drivers/tty/serial/sprd-serial.c

drivers/tty/serial/Kconfig +0 -0

index 26cec64..33b8f90 100644
@@ -113,6 +113,30 @@ config SERIAL_SB1250_DUART_CONSOLE
 
        If unsure, say Y.
 

Quoted 14 lines

drivers/tty/serial/Kconfig config SERIAL_SB1250_DUART_CONSOLE · line 126

Quoted 11 lines

drivers/tty/serial/Kconfig +11 -0

+config SERIAL_SPRD
+     tristate "Support for SPRD serial"
+     depends on ARM || ARM64
+     select SERIAL_CORE
+     help
+          This enables the driver for the Spreadtrum's serial.
+
+config SERIAL_SPRD_NR
+        int "Maximum number of sprd serial ports"
+        depends on SERIAL_SPRD
+        default "4"

This is not used below.

Ok, I'll remove it in v3.

Quoted 17 lines

drivers/tty/serial/Kconfig config SERIAL_SB1250_DUART_CONSOLE · line 137

Quoted 11 lines

drivers/tty/serial/Kconfig +11 -0

+
+config SERIAL_SPRD_CONSOLE
+        bool "SPRD UART console support"
+        depends on SERIAL_SPRD=y
+        select SERIAL_CORE_CONSOLE
+     select SERIAL_EARLYCON
+        help
+       Support for early debug console using Spreadtrum's serial. This enables
+       the console before standard serial driver is probed. This is enabled
+       with "earlycon=serial_sprd" on the kernel command line. The console is
+       enabled when early_param is processed.

There only appears to be an earlycon driver, and not "standard serial driver".

What happens after earlycon?

Quoted 8 lines

Surely there should be a real driver to take ownership of the UART?

As far as I can see it won't be possible to boot your platform to a prompt, because earlycon will have gone before that.

Thanks,
Mark.

Quoted 5 lines

We are planed to add standard serial driver after this patch-set is approved. In the first patch we contribute to the upstream, I'd like to add architecture related code of
Spreadtrum's Sharkl, and then we will add more functions about Sharkl3 SoC step by step.

The series is simple enough that the only issues I've noticed are minor. I'm happy with that.

However, the absence of a real UART driver means that this series alone is not sufficient to boot your platform to a usable state. Given that the rest of the series is simply plumbing, I think it would make sense for that to accompany a full UART driver (or perhaps some other I/O like ethernet) such that it's possible to interact with the platform.

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

drivers/tty/serial/sprd-serial.c new file +5 -0

+#define UART_TXD	0x0000
+#define UART_RXD	0x0004
+#define UART_STS0	0x0008
+#define UART_STS1	0x000C
+#define UART_IEN	0x0010

drivers/tty/serial/sprd-serial.c new file +15 -0

+static void serial_sprd_putc(struct uart_port *port, int c)
+{
+	while (!(readl(port->membase + UART_STS0) & UART_LSR_TX_OVER))
+		;
+	writeb(c, port->membase + UART_TXD);
+}
+
+static void serial_sprd_early_write(struct console *con, const char *s,
+				    unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, serial_sprd_putc);
+}
+

Quoted 13 lines · On Fri, 17 Oct 2014 17:54:25 +0800 Chunyan Zhang…

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

drivers/tty/serial/sprd-serial.c new file +10 -0

+#define UART_TXD     0x0000
+#define UART_RXD     0x0004
+#define UART_STS0    0x0008
+#define UART_STS1    0x000C
+#define UART_IEN     0x0010
+#define UART_ICLR    0x0014
+#define UART_CTL0    0x0018
+#define UART_CTL1    0x001C
+#define UART_CTL2    0x0020
+#define UART_CLKD0   0x0024

drivers/tty/serial/sprd-serial.c line 35

Quoted 5 lines

drivers/tty/serial/sprd-serial.c new file +5 -0

+#define UART_CLKD1   0x0028
+#define UART_STS2    0x002C
+
+/*line status */
+#define UART_LSR_TX_OVER     (0x1<<15)

Given we use UART_ for all the 8250 defines it might be better to use something else - SHARK_LSR_TX_OVER etc to avoid future confusion

From my point of view, private register macro could be treated as

Quoted 15 lines

drivers/tty/serial/sprd-serial.c new file +15 -0

+static void serial_sprd_putc(struct uart_port *port, int c)
+{
+     while (!(readl(port->membase + UART_STS0) & UART_LSR_TX_OVER))
+             ;
+     writeb(c, port->membase + UART_TXD);
+}
+
+static void serial_sprd_early_write(struct console *con, const char *s,
+                                 unsigned n)
+{
+     struct earlycon_device *dev = con->data;
+
+     uart_console_write(&dev->port, s, n, serial_sprd_putc);
+}
+

drivers/tty/serial/sprd-serial.c line 61

Quoted 10 lines

drivers/tty/serial/sprd-serial.c new file +10 -0

+static int __init serial_sprd_early_console_setup(
+                             struct earlycon_device *device,
+                             const char *opt)
+{
+     if (!device->port.membase)
+             return -ENODEV;
+
+     device->con->write = serial_sprd_early_write;
+     return 0;
+}

This seems fine but it would be useful to see both the earlycon and the main uart/console driver and how they fit together.

Alan

Quoted 16 lines · One Thousand Gnomes

Quoted 13 lines · On Fri, 17 Oct 2014 17:54:25 +0800 Chunyan Zhang…

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

drivers/tty/serial/sprd-serial.c new file +10 -0

+#define UART_TXD     0x0000
+#define UART_RXD     0x0004
+#define UART_STS0    0x0008
+#define UART_STS1    0x000C
+#define UART_IEN     0x0010
+#define UART_ICLR    0x0014
+#define UART_CTL0    0x0018
+#define UART_CTL1    0x001C
+#define UART_CTL2    0x0020
+#define UART_CLKD0   0x0024

Quoted 9 lines

drivers/tty/serial/sprd-serial.c line 35

Quoted 5 lines

drivers/tty/serial/sprd-serial.c new file +5 -0

+#define UART_CLKD1   0x0028
+#define UART_STS2    0x002C
+
+/*line status */
+#define UART_LSR_TX_OVER     (0x1<<15)

Given we use UART_ for all the 8250 defines it might be better to use something else - SHARK_LSR_TX_OVER etc to avoid future confusion

Does it matter if those macro are only used in the specific c file?

Quoted 1 line

From my point of view, private register macro could be treated as

static definitions like static variable or functions in C file. I also noted that many people use a prefix for the other manufacturers' macro definition in source file .
I have no intention to break the habit of kernel but just for discussion.

Quoted 28 lines · On Mon, 20 Oct 2014 18:23:38 +0800 Orson Zhai <[email protected]> wrote:

Quoted 16 lines · One Thousand Gnomes

Quoted 13 lines · On Fri, 17 Oct 2014 17:54:25 +0800 Chunyan Zhang…

Add serial driver for spreadtrum sharkl platform with earlycon support at first.

drivers/tty/serial/sprd-serial.c new file +10 -0

+#define UART_TXD     0x0000
+#define UART_RXD     0x0004
+#define UART_STS0    0x0008
+#define UART_STS1    0x000C
+#define UART_IEN     0x0010
+#define UART_ICLR    0x0014
+#define UART_CTL0    0x0018
+#define UART_CTL1    0x001C
+#define UART_CTL2    0x0020
+#define UART_CLKD0   0x0024

Quoted 9 lines

drivers/tty/serial/sprd-serial.c line 35

Quoted 5 lines

drivers/tty/serial/sprd-serial.c new file +5 -0

+#define UART_CLKD1   0x0028
+#define UART_STS2    0x002C
+
+/*line status */
+#define UART_LSR_TX_OVER     (0x1<<15)

Given we use UART_ for all the 8250 defines it might be better to use something else - SHARK_LSR_TX_OVER etc to avoid future confusion

Quoted 6 lines

Does it matter if those macro are only used in the specific c file?

Quoted 1 line

From my point of view, private register macro could be treated as

static definitions like static variable or functions in C file. I also noted that many people use a prefix for the other manufacturers' macro definition in source file .
I have no intention to break the habit of kernel but just for discussion.

Your problem is this. In the kernel headers are definitions like

include/uapi/linux/serial_reg.h:#define UART_TX 0 /* Out: Transmit
buffer */

you are adding identical (but conflicting in places) defines. If some random change in the include files causes serial_reg.h to be included by a header you include then it will break.

In addition people habitually use tools like LXR to figure out where defines and functions are.

Having these conflicting definitions will
cause confusion. Better they have prefixes.

Alan

Sharkl Platform is nominated as a SoC infrastructure that supports 4G/3G/2G standards based on ARMv8 multiple core architecture.Now we have only one SoC(Sharkl3) based on this Platform in developing.

Documentation: DT: Renamed of-serial.txt to 8250.txt