nds32/ag102: add ag102 soc support

Add lowlevel ag102 soc support.

Signed-off-by: Macpaul Lin <macpaul@andestech.com>
diff --git a/arch/nds32/cpu/n1213/ag102/timer.c b/arch/nds32/cpu/n1213/ag102/timer.c
new file mode 100644
index 0000000..caa36b8
--- /dev/null
+++ b/arch/nds32/cpu/n1213/ag102/timer.c
@@ -0,0 +1,205 @@
+/*
+ * (C) Copyright 2009 Faraday Technology
+ * Po-Yu Chuang <ratbert@faraday-tech.com>
+ *
+ * Copyright (C) 2011 Andes Technology Corporation
+ * Shawn Lin, Andes Technology Corporation <nobuhiro@andestech.com>
+ * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com>
+ *
+ * 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 <faraday/fttmr010.h>
+
+static ulong timestamp;
+static ulong lastdec;
+
+int timer_init(void)
+{
+	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+	unsigned int cr;
+
+	debug("%s()\n", __func__);
+
+	/* disable timers */
+	writel(0, &tmr->cr);
+
+#ifdef CONFIG_FTTMR010_EXT_CLK
+	/* use 32768Hz oscillator for RTC, WDT, TIMER */
+	ftpmu010_32768osc_enable();
+#endif
+
+	/* setup timer */
+	writel(TIMER_LOAD_VAL, &tmr->timer3_load);
+	writel(TIMER_LOAD_VAL, &tmr->timer3_counter);
+	writel(0, &tmr->timer3_match1);
+	writel(0, &tmr->timer3_match2);
+
+	/* we don't want timer to issue interrupts */
+	writel(FTTMR010_TM3_MATCH1 |
+	       FTTMR010_TM3_MATCH2 |
+	       FTTMR010_TM3_OVERFLOW,
+	       &tmr->interrupt_mask);
+
+	cr = readl(&tmr->cr);
+#ifdef CONFIG_FTTMR010_EXT_CLK
+	cr |= FTTMR010_TM3_CLOCK;	/* use external clock */
+#endif
+	cr |= FTTMR010_TM3_ENABLE;
+	writel(cr, &tmr->cr);
+
+	/* init the timestamp and lastdec value */
+	reset_timer_masked();
+
+	return 0;
+}
+
+/*
+ * timer without interrupts
+ */
+
+/*
+ * reset time
+ */
+void reset_timer_masked(void)
+{
+	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+
+	/* capure current decrementer value time */
+#ifdef CONFIG_FTTMR010_EXT_CLK
+	lastdec = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
+#else
+	lastdec = readl(&tmr->timer3_counter) / (CONFIG_SYS_CLK_FREQ / 2);
+#endif
+	timestamp = 0;		/* start "advancing" time stamp from 0 */
+
+	debug("%s(): lastdec = %lx\n", __func__, lastdec);
+}
+
+void reset_timer(void)
+{
+	debug("%s()\n", __func__);
+	reset_timer_masked();
+}
+
+/*
+ * return timer ticks
+ */
+ulong get_timer_masked(void)
+{
+	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+
+	/* current tick value */
+#ifdef CONFIG_FTTMR010_EXT_CLK
+	ulong now = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
+#else
+	ulong now = readl(&tmr->timer3_counter) / \
+			(CONFIG_SYS_CLK_FREQ / 2 / 1024);
+#endif
+
+	debug("%s(): now = %lx, lastdec = %lx\n", __func__, now, lastdec);
+
+	if (lastdec >= now) {
+		/*
+		 * normal mode (non roll)
+		 * move stamp fordward with absoulte diff ticks
+		 */
+		timestamp += lastdec - now;
+	} else {
+		/*
+		 * we have overflow of the count down timer
+		 *
+		 * nts = ts + ld + (TLV - now)
+		 * ts=old stamp, ld=time that passed before passing through -1
+		 * (TLV-now) amount of time after passing though -1
+		 * nts = new "advancing time stamp"...it could also roll and
+		 * cause problems.
+		 */
+		timestamp += lastdec + TIMER_LOAD_VAL - now;
+	}
+
+	lastdec = now;
+
+	debug("%s() returns %lx\n", __func__, timestamp);
+
+	return timestamp;
+}
+
+/*
+ * return difference between timer ticks and base
+ */
+ulong get_timer(ulong base)
+{
+	debug("%s(%lx)\n", __func__, base);
+	return get_timer_masked() - base;
+}
+
+void set_timer(ulong t)
+{
+	debug("%s(%lx)\n", __func__, t);
+	timestamp = t;
+}
+
+/* delay x useconds AND preserve advance timestamp value */
+void __udelay(unsigned long usec)
+{
+	struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+
+#ifdef CONFIG_FTTMR010_EXT_CLK
+	long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
+#else
+	long tmo = usec * ((CONFIG_SYS_CLK_FREQ / 2) / 1000) / 1000;
+#endif
+	unsigned long now, last = readl(&tmr->timer3_counter);
+
+	debug("%s(%lu)\n", __func__, usec);
+	while (tmo > 0) {
+		now = readl(&tmr->timer3_counter);
+		if (now > last) /* count down timer overflow */
+			tmo -= TIMER_LOAD_VAL + last - now;
+		else
+			tmo -= last - now;
+		last = now;
+	}
+}
+
+/*
+ * This function is derived from PowerPC code (read timebase as long long).
+ * On ARM it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+	debug("%s()\n", __func__);
+	return get_timer(0);
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+ulong get_tbclk(void)
+{
+	debug("%s()\n", __func__);
+#ifdef CONFIG_FTTMR010_EXT_CLK
+	return CONFIG_SYS_HZ;
+#else
+	return CONFIG_SYS_CLK_FREQ;
+#endif
+}