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authorMasahiro Yamada <yamada.m@jp.panasonic.com>2015-02-20 17:04:07 +0900
committerTom Rini <trini@ti.com>2015-02-21 08:23:51 -0500
commitef917ddb1d9240b075f3c03ddf6e246c89b86fa6 (patch)
tree52d222ac95f2042c025caa41bc710bc2ff137c33 /arch/arm/mach-nomadik/timer.c
parent56f86e39e80c5cbb17bec42cf6931cd203176830 (diff)
ARM: nomadik: move SoC sources to mach-nomadik
Move arch/arm/cpu/arm926ejs/nomadik/* -> arch/arm/mach-nomadik/* Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: Nomadik Linux Team <STN_WMM_nomadik_linux@list.st.com> Cc: Alessandro Rubini <rubini@unipv.it>
Diffstat (limited to 'arch/arm/mach-nomadik/timer.c')
-rw-r--r--arch/arm/mach-nomadik/timer.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/arm/mach-nomadik/timer.c b/arch/arm/mach-nomadik/timer.c
new file mode 100644
index 0000000000..775d0b7488
--- /dev/null
+++ b/arch/arm/mach-nomadik/timer.c
@@ -0,0 +1,71 @@
+/*
+ * (C) Copyright 2009 Alessandro Rubini
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/mtu.h>
+
+/*
+ * The timer is a decrementer, we'll left it free running at 2.4MHz.
+ * We have 2.4 ticks per microsecond and an overflow in almost 30min
+ */
+#define TIMER_CLOCK (24 * 100 * 1000)
+#define COUNT_TO_USEC(x) ((x) * 5 / 12) /* overflows at 6min */
+#define USEC_TO_COUNT(x) ((x) * 12 / 5) /* overflows at 6min */
+#define TICKS_PER_HZ (TIMER_CLOCK / CONFIG_SYS_HZ)
+#define TICKS_TO_HZ(x) ((x) / TICKS_PER_HZ)
+
+/* macro to read the decrementing 32 bit timer as an increasing count */
+#define READ_TIMER() (0 - readl(CONFIG_SYS_TIMERBASE + MTU_VAL(0)))
+
+/* Configure a free-running, auto-wrap counter with no prescaler */
+int timer_init(void)
+{
+ ulong val;
+
+ writel(MTU_CRn_ENA | MTU_CRn_PRESCALE_1 | MTU_CRn_32BITS,
+ CONFIG_SYS_TIMERBASE + MTU_CR(0));
+
+ /* Reset the timer */
+ writel(0, CONFIG_SYS_TIMERBASE + MTU_LR(0));
+ /*
+ * The load-register isn't really immediate: it changes on clock
+ * edges, so we must wait for our newly-written value to appear.
+ * Since we might miss reading 0, wait for any change in value.
+ */
+ val = READ_TIMER();
+ while (READ_TIMER() == val)
+ ;
+
+ return 0;
+}
+
+/* Return how many HZ passed since "base" */
+ulong get_timer(ulong base)
+{
+ return TICKS_TO_HZ(READ_TIMER()) - base;
+}
+
+/* Delay x useconds */
+void __udelay(unsigned long usec)
+{
+ ulong ini, end;
+
+ ini = READ_TIMER();
+ end = ini + USEC_TO_COUNT(usec);
+ while ((signed)(end - READ_TIMER()) > 0)
+ ;
+}
+
+unsigned long long get_ticks(void)
+{
+ return get_timer(0);
+}
+
+ulong get_tbclk(void)
+{
+ return CONFIG_SYS_HZ;
+}