summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/clocksource/mmio.c
diff options
context:
space:
mode:
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/drivers/clocksource/mmio.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/drivers/clocksource/mmio.c')
-rw-r--r--kernel/drivers/clocksource/mmio.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/kernel/drivers/clocksource/mmio.c b/kernel/drivers/clocksource/mmio.c
new file mode 100644
index 000000000..1593ade2a
--- /dev/null
+++ b/kernel/drivers/clocksource/mmio.c
@@ -0,0 +1,73 @@
+/*
+ * Generic MMIO clocksource support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/clocksource.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+
+struct clocksource_mmio {
+ void __iomem *reg;
+ struct clocksource clksrc;
+};
+
+static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
+{
+ return container_of(c, struct clocksource_mmio, clksrc);
+}
+
+cycle_t clocksource_mmio_readl_up(struct clocksource *c)
+{
+ return (cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readl_down(struct clocksource *c)
+{
+ return ~(cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
+}
+
+cycle_t clocksource_mmio_readw_up(struct clocksource *c)
+{
+ return (cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg);
+}
+
+cycle_t clocksource_mmio_readw_down(struct clocksource *c)
+{
+ return ~(cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
+}
+
+/**
+ * clocksource_mmio_init - Initialize a simple mmio based clocksource
+ * @base: Virtual address of the clock readout register
+ * @name: Name of the clocksource
+ * @hz: Frequency of the clocksource in Hz
+ * @rating: Rating of the clocksource
+ * @bits: Number of valid bits
+ * @read: One of clocksource_mmio_read*() above
+ */
+int __init clocksource_mmio_init(void __iomem *base, const char *name,
+ unsigned long hz, int rating, unsigned bits,
+ cycle_t (*read)(struct clocksource *))
+{
+ struct clocksource_mmio *cs;
+
+ if (bits > 32 || bits < 16)
+ return -EINVAL;
+
+ cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
+ if (!cs)
+ return -ENOMEM;
+
+ cs->reg = base;
+ cs->clksrc.name = name;
+ cs->clksrc.rating = rating;
+ cs->clksrc.read = read;
+ cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
+ cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+ return clocksource_register_hz(&cs->clksrc, hz);
+}