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-rw-r--r--cpu/arm1136/mx35/timer.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/cpu/arm1136/mx35/timer.c b/cpu/arm1136/mx35/timer.c
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+++ b/cpu/arm1136/mx35/timer.c
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+/*
+ * (C) Copyright 2007
+ * Sascha Hauer, Pengutronix
+ *
+ * (C) Copyright 2008-2009 Freescale Semiconductor, Inc.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/arch/mx35.h>
+
+/* General purpose timers registers */
+#define GPTCR __REG(GPT1_BASE_ADDR) /* Control register */
+#define GPTPR __REG(GPT1_BASE_ADDR + 0x4) /* Prescaler register */
+#define GPTSR __REG(GPT1_BASE_ADDR + 0x8) /* Status register */
+#define GPTCNT __REG(GPT1_BASE_ADDR + 0x24) /* Counter register */
+
+/* General purpose timers bitfields */
+#define GPTCR_SWR (1<<15) /* Software reset */
+#define GPTCR_FRR (1<<9) /* Freerun / restart */
+#define GPTCR_CLKSOURCE_32 (4<<6) /* Clock source */
+#define GPTCR_TEN (1) /* Timer enable */
+
+static inline void setup_gpt()
+{
+ int i;
+ static int init_done;
+
+ if (init_done)
+ return;
+
+ init_done = 1;
+
+ /* setup GP Timer 1 */
+ GPTCR = GPTCR_SWR;
+ for (i = 0; i < 100; i++)
+ GPTCR = 0; /* We have no udelay by now */
+ GPTPR = 0; /* 32Khz */
+ /* Freerun Mode, PERCLK1 input */
+ GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN;
+}
+
+int timer_init(void)
+{
+ setup_gpt();
+
+ return 0;
+}
+
+void reset_timer(void)
+{
+ reset_timer_masked();
+}
+
+void reset_timer_masked(void)
+{
+ GPTCR = 0;
+ /* Freerun Mode, PERCLK1 input */
+ GPTCR = GPTCR_CLKSOURCE_32 | GPTCR_TEN;
+}
+
+ulong get_timer_masked(void)
+{
+ ulong val = GPTCNT;
+ return val;
+}
+
+ulong get_timer(ulong base)
+{
+ return get_timer_masked() - base;
+}
+
+void set_timer(ulong t)
+{
+}
+
+/* delay x useconds AND perserve advance timstamp value */
+void udelay(unsigned long usec)
+{
+ ulong tmo, tmp;
+
+ setup_gpt();
+
+ /* if "big" number, spread normalization to seconds */
+ if (usec >= 1000) {
+ /* start to normalize for usec to ticks per sec */
+ tmo = usec / 1000;
+ /* find number of "ticks" to wait to achieve target */
+ tmo *= CONFIG_SYS_HZ;
+ tmo /= 1000; /* finish normalize. */
+ } else {/* else small number, don't kill it prior to HZ multiply */
+ tmo = usec * CONFIG_SYS_HZ;
+ tmo /= (1000 * 1000);
+ }
+
+ tmp = get_timer(0); /* get current timestamp */
+ /* if setting this forward will roll time stamp */
+ if ((tmo + tmp + 1) < tmp)
+ /* reset "advancing" timestamp to 0, set lastinc value */
+ reset_timer_masked();
+ else /* else, set advancing stamp wake up time */
+ tmo += tmp;
+ while (get_timer_masked() < tmo) /* loop till event */
+ /*NOP*/;
+}
+
+void reset_cpu(ulong addr)
+{
+ __REG16(WDOG_BASE_ADDR) = 4;
+}