[PATCH v6 2/3] clocksource: Add NPS400 timers driver
Noam Camus
noamca at mellanox.com
Mon Mar 21 07:24:31 PDT 2016
From: Noam Camus <noamc at ezchip.com>
Add internal tick generator which is shared by all cores.
Each cluster of cores view it through dedicated address.
This is used for SMP system where all CPUs synced by same
clock source.
Signed-off-by: Noam Camus <noamc at ezchip.com>
Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
Cc: Rob Herring <robh+dt at kernel.org>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: John Stultz <john.stultz at linaro.org>
Acked-by: Vineet Gupta <vgupta at synopsys.com>
---
.../bindings/timer/ezchip,nps400-timer.txt | 15 +++
drivers/clocksource/Kconfig | 10 ++
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-nps.c | 98 ++++++++++++++++++++
4 files changed, 124 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/timer/ezchip,nps400-timer.txt
create mode 100644 drivers/clocksource/timer-nps.c
diff --git a/Documentation/devicetree/bindings/timer/ezchip,nps400-timer.txt b/Documentation/devicetree/bindings/timer/ezchip,nps400-timer.txt
new file mode 100644
index 0000000..c8c03d7
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/ezchip,nps400-timer.txt
@@ -0,0 +1,15 @@
+NPS Network Processor
+
+Required properties:
+
+- compatible : should be "ezchip,nps400-timer"
+
+Clocks required for compatible = "ezchip,nps400-timer":
+- clocks : Must contain a single entry describing the clock input
+
+Example:
+
+timer {
+ compatible = "ezchip,nps400-timer";
+ clocks = <&sysclk>;
+};
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 2eb5f0e..fa7be50 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -132,6 +132,16 @@ config CLKSRC_TI_32K
This option enables support for Texas Instruments 32.768 Hz clocksource
available on many OMAP-like platforms.
+config CLKSRC_NPS
+ bool "NPS400 clocksource driver" if COMPILE_TEST
+ depends on !PHYS_ADDR_T_64BIT
+ select CLKSRC_MMIO
+ select CLKSRC_OF if OF
+ help
+ NPS400 clocksource support.
+ Got 64 bit counter with update rate up to 1000MHz.
+ This counter is accessed via couple of 32 bit memory mapped registers.
+
config CLKSRC_STM32
bool "Clocksource for STM32 SoCs" if !ARCH_STM32
depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST)
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 56bd16e..056cffd 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_CLKSRC_QCOM) += qcom-timer.o
obj-$(CONFIG_MTK_TIMER) += mtk_timer.o
obj-$(CONFIG_CLKSRC_PISTACHIO) += time-pistachio.o
obj-$(CONFIG_CLKSRC_TI_32K) += timer-ti-32k.o
+obj-$(CONFIG_CLKSRC_NPS) += timer-nps.o
obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o
obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o
diff --git a/drivers/clocksource/timer-nps.c b/drivers/clocksource/timer-nps.c
new file mode 100644
index 0000000..d461089
--- /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);
--
1.7.1
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