Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 106 insertions, 0 deletions

diff --git a/kernel/arch/arm/mach-davinci/serial.c b/kernel/arch/arm/mach-davinci/serial.c
new file mode 100644
index 000000000..951b620bf
--- /dev/null
+++ b/kernel/arch/arm/mach-davinci/serial.c
@@ -0,0 +1,106 @@
+/*
+ * TI DaVinci serial driver
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <mach/serial.h>
+#include <mach/cputype.h>
+
+static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
+				    int value)
+{
+	offset <<= p->regshift;
+
+	WARN_ONCE(!p->membase, "unmapped write: uart[%d]\n", offset);
+
+	__raw_writel(value, p->membase + offset);
+}
+
+static void __init davinci_serial_reset(struct plat_serial8250_port *p)
+{
+	unsigned int pwremu = 0;
+
+	serial_write_reg(p, UART_IER, 0);  /* disable all interrupts */
+
+	/* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */
+	serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);
+	mdelay(10);
+
+	pwremu |= (0x3 << 13);
+	pwremu |= 0x1;
+	serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu);
+
+	if (cpu_is_davinci_dm646x())
+		serial_write_reg(p, UART_DM646X_SCR,
+				 UART_DM646X_SCR_TX_WATERMARK);
+}
+
+int __init davinci_serial_init(struct platform_device *serial_dev)
+{
+	int i, ret = 0;
+	struct device *dev;
+	struct plat_serial8250_port *p;
+	struct clk *clk;
+
+	/*
+	 * Make sure the serial ports are muxed on at this point.
+	 * You have to mux them off in device drivers later on if not needed.
+	 */
+	for (i = 0; serial_dev[i].dev.platform_data != NULL; i++) {
+		dev = &serial_dev[i].dev;
+		p = dev->platform_data;
+
+		ret = platform_device_register(&serial_dev[i]);
+		if (ret)
+			continue;
+
+		clk = clk_get(dev, NULL);
+		if (IS_ERR(clk)) {
+			pr_err("%s:%d: failed to get UART%d clock\n",
+			       __func__, __LINE__, i);
+			continue;
+		}
+
+		clk_prepare_enable(clk);
+
+		p->uartclk = clk_get_rate(clk);
+
+		if (!p->membase && p->mapbase) {
+			p->membase = ioremap(p->mapbase, SZ_4K);
+
+			if (p->membase)
+				p->flags &= ~UPF_IOREMAP;
+			else
+				pr_err("uart regs ioremap failed\n");
+		}
+
+		if (p->membase && p->type != PORT_AR7)
+			davinci_serial_reset(p);
+	}
+	return ret;
+}