ARM1176: TI: TNETV107X soc initial support

TNETV107X is a Texas Instruments SoC based on an ARM1176 core, and with a
bunch on on-chip integrated peripherals.  This is an initial commit with
basic functionality, more commits with drivers, etc. to follow.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/arch/arm/cpu/arm1176/tnetv107x/wdt.c b/arch/arm/cpu/arm1176/tnetv107x/wdt.c
new file mode 100644
index 0000000..18aadb0
--- /dev/null
+++ b/arch/arm/cpu/arm1176/tnetv107x/wdt.c
@@ -0,0 +1,180 @@
+/*
+ * TNETV107X: Watchdog timer implementation (for reset)
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 <common.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+
+#define MAX_DIV		0xFFFE0001
+
+struct wdt_regs {
+	u32 kick_lock;
+#define KICK_LOCK_1	0x5555
+#define KICK_LOCK_2	0xaaaa
+	u32 kick;
+
+	u32 change_lock;
+#define CHANGE_LOCK_1	0x6666
+#define CHANGE_LOCK_2	0xbbbb
+	u32 change;
+
+	u32 disable_lock;
+#define DISABLE_LOCK_1	0x7777
+#define DISABLE_LOCK_2	0xcccc
+#define DISABLE_LOCK_3	0xdddd
+	u32 disable;
+
+	u32 prescale_lock;
+#define PRESCALE_LOCK_1	0x5a5a
+#define PRESCALE_LOCK_2	0xa5a5
+	u32 prescale;
+};
+
+static struct wdt_regs* regs = (struct wdt_regs *)TNETV107X_WDT0_ARM_BASE;
+
+#define wdt_reg_read(reg)	__raw_readl(&regs->reg)
+#define wdt_reg_write(reg, val)	__raw_writel((val), &regs->reg)
+
+static int write_prescale_reg(unsigned long prescale_value)
+{
+	wdt_reg_write(prescale_lock, PRESCALE_LOCK_1);
+	if ((wdt_reg_read(prescale_lock) & 0x3) != 0x1)
+		return -1;
+
+	wdt_reg_write(prescale_lock, PRESCALE_LOCK_2);
+	if ((wdt_reg_read(prescale_lock) & 0x3) != 0x3)
+		return -1;
+
+	wdt_reg_write(prescale, prescale_value);
+
+	return 0;
+}
+
+static int write_change_reg(unsigned long initial_timer_value)
+{
+	wdt_reg_write(change_lock, CHANGE_LOCK_1);
+	if ((wdt_reg_read(change_lock) & 0x3) != 0x1)
+		return -1;
+
+	wdt_reg_write(change_lock, CHANGE_LOCK_2);
+	if ((wdt_reg_read(change_lock) & 0x3) != 0x3)
+		return -1;
+
+	wdt_reg_write(change, initial_timer_value);
+
+	return 0;
+}
+
+static int wdt_control(unsigned long disable_value)
+{
+	wdt_reg_write(disable_lock, DISABLE_LOCK_1);
+	if ((wdt_reg_read(disable_lock) & 0x3) != 0x1)
+		return -1;
+
+	wdt_reg_write(disable_lock, DISABLE_LOCK_2);
+	if ((wdt_reg_read(disable_lock) & 0x3) != 0x2)
+		return -1;
+
+	wdt_reg_write(disable_lock, DISABLE_LOCK_3);
+	if ((wdt_reg_read(disable_lock) & 0x3) != 0x3)
+		return -1;
+
+	wdt_reg_write(disable, disable_value);
+	return 0;
+}
+
+static int wdt_set_period(unsigned long msec)
+{
+	unsigned long change_value, count_value;
+	unsigned long prescale_value = 1;
+	unsigned long refclk_khz, maxdiv;
+	int ret;
+
+	refclk_khz = clk_get_rate(TNETV107X_LPSC_WDT_ARM);
+	maxdiv = (MAX_DIV / refclk_khz);
+
+	if ((!msec) || (msec > maxdiv))
+		return -1;
+
+	count_value = refclk_khz * msec;
+	if (count_value > 0xffff) {
+		change_value = count_value / 0xffff + 1;
+		prescale_value = count_value / change_value;
+	} else {
+		change_value = count_value;
+	}
+
+	ret = write_prescale_reg(prescale_value - 1);
+	if (ret)
+		return ret;
+
+	ret = write_change_reg(change_value);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+unsigned long last_wdt = -1;
+
+int wdt_start(unsigned long msecs)
+{
+	int ret;
+	ret = wdt_control(0);
+	if (ret)
+		return ret;
+	ret = wdt_set_period(msecs);
+	if (ret)
+		return ret;
+	ret = wdt_control(1);
+	if (ret)
+		return ret;
+	ret = wdt_kick();
+	last_wdt = msecs;
+	return ret;
+}
+
+int wdt_stop(void)
+{
+	last_wdt = -1;
+	return wdt_control(0);
+}
+
+int wdt_kick(void)
+{
+	wdt_reg_write(kick_lock, KICK_LOCK_1);
+	if ((wdt_reg_read(kick_lock) & 0x3) != 0x1)
+		return -1;
+
+	wdt_reg_write(kick_lock, KICK_LOCK_2);
+	if ((wdt_reg_read(kick_lock) & 0x3) != 0x3)
+		return -1;
+
+	wdt_reg_write(kick, 1);
+	return 0;
+}
+
+void reset_cpu(ulong addr)
+{
+	clk_enable(TNETV107X_LPSC_WDT_ARM);
+	wdt_start(1);
+	wdt_kick();
+}