summaryrefslogtreecommitdiffstats
path: root/drivers/clocksource/timer-nps.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clocksource/timer-nps.c')
-rw-r--r--drivers/clocksource/timer-nps.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-nps.c b/drivers/clocksource/timer-nps.c
new file mode 100644
index 000000000000..d46108920b2c
--- /dev/null
+++ b/drivers/clocksource/timer-nps.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2016, Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/cpu.h>
+#include <soc/nps/common.h>
+
+#define NPS_MSU_TICK_LOW 0xC8
+#define NPS_CLUSTER_OFFSET 8
+#define NPS_CLUSTER_NUM 16
+
+/* This array is per cluster of CPUs (Each NPS400 cluster got 256 CPUs) */
+static void *nps_msu_reg_low_addr[NPS_CLUSTER_NUM] __read_mostly;
+
+static unsigned long nps_timer_rate;
+
+static cycle_t nps_clksrc_read(struct clocksource *clksrc)
+{
+ int cluster = raw_smp_processor_id() >> NPS_CLUSTER_OFFSET;
+
+ return (cycle_t)ioread32be(nps_msu_reg_low_addr[cluster]);
+}
+
+static void __init nps_setup_clocksource(struct device_node *node,
+ struct clk *clk)
+{
+ int ret, cluster;
+
+ for (cluster = 0; cluster < NPS_CLUSTER_NUM; cluster++)
+ nps_msu_reg_low_addr[cluster] =
+ nps_host_reg((cluster << NPS_CLUSTER_OFFSET),
+ NPS_MSU_BLKID, NPS_MSU_TICK_LOW);
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("Couldn't enable parent clock\n");
+ return;
+ }
+
+ nps_timer_rate = clk_get_rate(clk);
+
+ ret = clocksource_mmio_init(nps_msu_reg_low_addr, "EZnps-tick",
+ nps_timer_rate, 301, 32, nps_clksrc_read);
+ if (ret) {
+ pr_err("Couldn't register clock source.\n");
+ clk_disable_unprepare(clk);
+ }
+}
+
+static void __init nps_timer_init(struct device_node *node)
+{
+ struct clk *clk;
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ pr_err("Can't get timer clock.\n");
+ return;
+ }
+
+ nps_setup_clocksource(node, clk);
+}
+
+CLOCKSOURCE_OF_DECLARE(ezchip_nps400_clksrc, "ezchip,nps400-timer",
+ nps_timer_init);