armv7: Add ST-Ericsson u8500 arch

Based on ST-Ericsson internal git repo.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: John Rigby <john.rigby@linaro.org>
CC: Albert Aribaud <albert.aribaud@free.fr>

1 files changed, 154 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/u8500/timer.c b/arch/arm/cpu/armv7/u8500/timer.c
new file mode 100644
index 0000000000..8e96eaa771
--- /dev/null
+++ b/arch/arm/cpu/armv7/u8500/timer.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2010 Linaro Limited
+ * John Rigby <john.rigby@linaro.org>
+ *
+ * Based on original from Linux kernel source and
+ * internal ST-Ericsson U-Boot source.
+ * (C) Copyright 2009 Alessandro Rubini
+ * (C) Copyright 2010 ST-Ericsson
+ *
+ * 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/io.h>
+#include <asm/arch/hardware.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * The MTU device has some interrupt control registers
+ * followed by 4 timers.
+ */
+
+/* The timers */
+struct u8500_mtu_timer {
+	u32 lr;			/* Load value */
+	u32 cv;			/* Current value */
+	u32 cr;			/* Control reg */
+	u32 bglr;		/* ??? */
+};
+
+/* The MTU that contains the timers */
+struct u8500_mtu {
+	u32 imsc;		/* Interrupt mask set/clear */
+	u32 ris;		/* Raw interrupt status */
+	u32 mis;		/* Masked interrupt status */
+	u32 icr;		/* Interrupt clear register */
+	struct u8500_mtu_timer pt[4];
+};
+
+/* bits for the control register */
+#define MTU_CR_ONESHOT		0x01	/* if 0 = wraps reloading from BGLR */
+#define MTU_CR_32BITS		0x02
+
+#define MTU_CR_PRESCALE_1	0x00
+#define MTU_CR_PRESCALE_16	0x04
+#define MTU_CR_PRESCALE_256	0x08
+#define MTU_CR_PRESCALE_MASK	0x0c
+
+#define MTU_CR_PERIODIC		0x40	/* if 0 = free-running */
+#define MTU_CR_ENA		0x80
+
+/*
+ * The MTU is clocked at 133 MHz by default. (V1 and later)
+ */
+#define TIMER_CLOCK		(133 * 1000 * 1000 / 16)
+#define COUNT_TO_USEC(x)	((x) * 16 / 133)
+#define USEC_TO_COUNT(x)	((x) * 133 / 16)
+#define TICKS_PER_HZ		(TIMER_CLOCK / CONFIG_SYS_HZ)
+#define TICKS_TO_HZ(x)		((x) / TICKS_PER_HZ)
+#define TIMER_LOAD_VAL		0xffffffff
+
+/*
+ * MTU timer to use (from 0 to 3).
+ */
+#define MTU_TIMER 2
+
+static struct u8500_mtu_timer *timer_base =
+	&((struct u8500_mtu *)U8500_MTU0_BASE_V1)->pt[MTU_TIMER];
+
+/* macro to read the 32 bit timer: since it decrements, we invert read value */
+#define READ_TIMER() (~readl(&timer_base->cv))
+
+/* Configure a free-running, auto-wrap counter with /16 prescaler */
+int timer_init(void)
+{
+	writel(MTU_CR_ENA | MTU_CR_PRESCALE_16 | MTU_CR_32BITS,
+	       &timer_base->cr);
+	return 0;
+}
+
+ulong get_timer_masked(void)
+{
+	/* current tick value */
+	ulong now = TICKS_TO_HZ(READ_TIMER());
+
+	if (now >= gd->lastinc)	/* normal (non rollover) */
+		gd->tbl += (now - gd->lastinc);
+	else			/* rollover */
+		gd->tbl += (TICKS_TO_HZ(TIMER_LOAD_VAL) - gd->lastinc) + now;
+	gd->lastinc = now;
+	return gd->tbl;
+}
+
+/* Delay x useconds */
+void __udelay(ulong usec)
+{
+	long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
+	ulong now, last = READ_TIMER();
+
+	while (tmo > 0) {
+		now = READ_TIMER();
+		if (now > last)	/* normal (non rollover) */
+			tmo -= now - last;
+		else		/* rollover */
+			tmo -= TIMER_LOAD_VAL - last + now;
+		last = now;
+	}
+}
+
+ulong get_timer(ulong base)
+{
+	return get_timer_masked() - base;
+}
+
+void set_timer(ulong t)
+{
+	gd->tbl = t;
+}
+
+/*
+ * Emulation of Power architecture long long timebase.
+ *
+ * TODO: Support gd->tbu for real long long timebase.
+ */
+unsigned long long get_ticks(void)
+{
+	return get_timer(0);
+}
+
+/*
+ * Emulation of Power architecture timebase.
+ * NB: Low resolution compared to Power tbclk.
+ */
+ulong get_tbclk(void)
+{
+	return CONFIG_SYS_HZ;
+}