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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/m68k/coldfire/dma_timer.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/m68k/coldfire/dma_timer.c')
-rw-r--r--kernel/arch/m68k/coldfire/dma_timer.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/kernel/arch/m68k/coldfire/dma_timer.c b/kernel/arch/m68k/coldfire/dma_timer.c
new file mode 100644
index 000000000..235ad57c4
--- /dev/null
+++ b/kernel/arch/m68k/coldfire/dma_timer.c
@@ -0,0 +1,81 @@
+/*
+ * dma_timer.c -- Freescale ColdFire DMA Timer.
+ *
+ * Copyright (C) 2007, Benedikt Spranger <b.spranger@linutronix.de>
+ * Copyright (C) 2008. Sebastian Siewior, Linutronix
+ *
+ */
+
+#include <linux/clocksource.h>
+#include <linux/io.h>
+
+#include <asm/machdep.h>
+#include <asm/coldfire.h>
+#include <asm/mcfpit.h>
+#include <asm/mcfsim.h>
+
+#define DMA_TIMER_0 (0x00)
+#define DMA_TIMER_1 (0x40)
+#define DMA_TIMER_2 (0x80)
+#define DMA_TIMER_3 (0xc0)
+
+#define DTMR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x400)
+#define DTXMR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x402)
+#define DTER0 (MCF_IPSBAR + DMA_TIMER_0 + 0x403)
+#define DTRR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x404)
+#define DTCR0 (MCF_IPSBAR + DMA_TIMER_0 + 0x408)
+#define DTCN0 (MCF_IPSBAR + DMA_TIMER_0 + 0x40c)
+
+#define DMA_FREQ ((MCF_CLK / 2) / 16)
+
+/* DTMR */
+#define DMA_DTMR_RESTART (1 << 3)
+#define DMA_DTMR_CLK_DIV_1 (1 << 1)
+#define DMA_DTMR_CLK_DIV_16 (2 << 1)
+#define DMA_DTMR_ENABLE (1 << 0)
+
+static cycle_t cf_dt_get_cycles(struct clocksource *cs)
+{
+ return __raw_readl(DTCN0);
+}
+
+static struct clocksource clocksource_cf_dt = {
+ .name = "coldfire_dma_timer",
+ .rating = 200,
+ .read = cf_dt_get_cycles,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init init_cf_dt_clocksource(void)
+{
+ /*
+ * We setup DMA timer 0 in free run mode. This incrementing counter is
+ * used as a highly precious clock source. With MCF_CLOCK = 150 MHz we
+ * get a ~213 ns resolution and the 32bit register will overflow almost
+ * every 15 minutes.
+ */
+ __raw_writeb(0x00, DTXMR0);
+ __raw_writeb(0x00, DTER0);
+ __raw_writel(0x00000000, DTRR0);
+ __raw_writew(DMA_DTMR_CLK_DIV_16 | DMA_DTMR_ENABLE, DTMR0);
+ return clocksource_register_hz(&clocksource_cf_dt, DMA_FREQ);
+}
+
+arch_initcall(init_cf_dt_clocksource);
+
+#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
+#define CYC2NS_SCALE ((1000000 << CYC2NS_SCALE_FACTOR) / (DMA_FREQ / 1000))
+
+static unsigned long long cycles2ns(unsigned long cycl)
+{
+ return (unsigned long long) ((unsigned long long)cycl *
+ CYC2NS_SCALE) >> CYC2NS_SCALE_FACTOR;
+}
+
+unsigned long long sched_clock(void)
+{
+ unsigned long cycl = __raw_readl(DTCN0);
+
+ return cycles2ns(cycl);
+}