1 files changed, 284 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-nps.c b/drivers/clocksource/timer-nps.c
new file mode 100644
index 000000000..7b6bb0df9
--- /dev/null
+++ b/drivers/clocksource/timer-nps.c
@@ -0,0 +1,284 @@
+/*
+ * 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 int __init nps_get_timer_clk(struct device_node *node,
+			     unsigned long *timer_freq,
+			     struct clk **clk)
+{
+	int ret;
+
+	*clk = of_clk_get(node, 0);
+	ret = PTR_ERR_OR_ZERO(*clk);
+	if (ret) {
+		pr_err("timer missing clk\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(*clk);
+	if (ret) {
+		pr_err("Couldn't enable parent clk\n");
+		clk_put(*clk);
+		return ret;
+	}
+
+	*timer_freq = clk_get_rate(*clk);
+	if (!(*timer_freq)) {
+		pr_err("Couldn't get clk rate\n");
+		clk_disable_unprepare(*clk);
+		clk_put(*clk);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static u64 nps_clksrc_read(struct clocksource *clksrc)
+{
+	int cluster = raw_smp_processor_id() >> NPS_CLUSTER_OFFSET;
+
+	return (u64)ioread32be(nps_msu_reg_low_addr[cluster]);
+}
+
+static int __init nps_setup_clocksource(struct device_node *node)
+{
+	int ret, cluster;
+	struct clk *clk;
+	unsigned long nps_timer1_freq;
+
+
+	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 = nps_get_timer_clk(node, &nps_timer1_freq, &clk);
+	if (ret)
+		return ret;
+
+	ret = clocksource_mmio_init(nps_msu_reg_low_addr, "nps-tick",
+				    nps_timer1_freq, 300, 32, nps_clksrc_read);
+	if (ret) {
+		pr_err("Couldn't register clock source.\n");
+		clk_disable_unprepare(clk);
+	}
+
+	return ret;
+}
+
+TIMER_OF_DECLARE(ezchip_nps400_clksrc, "ezchip,nps400-timer",
+		       nps_setup_clocksource);
+TIMER_OF_DECLARE(ezchip_nps400_clk_src, "ezchip,nps400-timer1",
+		       nps_setup_clocksource);
+
+#ifdef CONFIG_EZNPS_MTM_EXT
+#include <soc/nps/mtm.h>
+
+/* Timer related Aux registers */
+#define NPS_REG_TIMER0_TSI	0xFFFFF850
+#define NPS_REG_TIMER0_LIMIT	0x23
+#define NPS_REG_TIMER0_CTRL	0x22
+#define NPS_REG_TIMER0_CNT	0x21
+
+/*
+ * Interrupt Enabled (IE) - re-arm the timer
+ * Not Halted (NH) - is cleared when working with JTAG (for debug)
+ */
+#define TIMER0_CTRL_IE		BIT(0)
+#define TIMER0_CTRL_NH		BIT(1)
+
+static unsigned long nps_timer0_freq;
+static unsigned long nps_timer0_irq;
+
+static void nps_clkevent_rm_thread(void)
+{
+	int thread;
+	unsigned int cflags, enabled_threads;
+
+	hw_schd_save(&cflags);
+
+	enabled_threads = read_aux_reg(NPS_REG_TIMER0_TSI);
+
+	/* remove thread from TSI1 */
+	thread = read_aux_reg(CTOP_AUX_THREAD_ID);
+	enabled_threads &= ~(1 << thread);
+	write_aux_reg(NPS_REG_TIMER0_TSI, enabled_threads);
+
+	/* Acknowledge and if needed re-arm the timer */
+	if (!enabled_threads)
+		write_aux_reg(NPS_REG_TIMER0_CTRL, TIMER0_CTRL_NH);
+	else
+		write_aux_reg(NPS_REG_TIMER0_CTRL,
+			      TIMER0_CTRL_IE | TIMER0_CTRL_NH);
+
+	hw_schd_restore(cflags);
+}
+
+static void nps_clkevent_add_thread(unsigned long delta)
+{
+	int thread;
+	unsigned int cflags, enabled_threads;
+
+	hw_schd_save(&cflags);
+
+	/* add thread to TSI1 */
+	thread = read_aux_reg(CTOP_AUX_THREAD_ID);
+	enabled_threads = read_aux_reg(NPS_REG_TIMER0_TSI);
+	enabled_threads |= (1 << thread);
+	write_aux_reg(NPS_REG_TIMER0_TSI, enabled_threads);
+
+	/* set next timer event */
+	write_aux_reg(NPS_REG_TIMER0_LIMIT, delta);
+	write_aux_reg(NPS_REG_TIMER0_CNT, 0);
+	write_aux_reg(NPS_REG_TIMER0_CTRL,
+		      TIMER0_CTRL_IE | TIMER0_CTRL_NH);
+
+	hw_schd_restore(cflags);
+}
+
+/*
+ * Whenever anyone tries to change modes, we just mask interrupts
+ * and wait for the next event to get set.
+ */
+static int nps_clkevent_set_state(struct clock_event_device *dev)
+{
+	nps_clkevent_rm_thread();
+	disable_percpu_irq(nps_timer0_irq);
+
+	return 0;
+}
+
+static int nps_clkevent_set_next_event(unsigned long delta,
+				       struct clock_event_device *dev)
+{
+	nps_clkevent_add_thread(delta);
+	enable_percpu_irq(nps_timer0_irq, IRQ_TYPE_NONE);
+
+	return 0;
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, nps_clockevent_device) = {
+	.name				=	"NPS Timer0",
+	.features			=	CLOCK_EVT_FEAT_ONESHOT,
+	.rating				=	300,
+	.set_next_event			=	nps_clkevent_set_next_event,
+	.set_state_oneshot		=	nps_clkevent_set_state,
+	.set_state_oneshot_stopped	=	nps_clkevent_set_state,
+	.set_state_shutdown		=	nps_clkevent_set_state,
+	.tick_resume			=	nps_clkevent_set_state,
+};
+
+static irqreturn_t timer_irq_handler(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	nps_clkevent_rm_thread();
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static int nps_timer_starting_cpu(unsigned int cpu)
+{
+	struct clock_event_device *evt = this_cpu_ptr(&nps_clockevent_device);
+
+	evt->cpumask = cpumask_of(smp_processor_id());
+
+	clockevents_config_and_register(evt, nps_timer0_freq, 0, ULONG_MAX);
+	enable_percpu_irq(nps_timer0_irq, IRQ_TYPE_NONE);
+
+	return 0;
+}
+
+static int nps_timer_dying_cpu(unsigned int cpu)
+{
+	disable_percpu_irq(nps_timer0_irq);
+	return 0;
+}
+
+static int __init nps_setup_clockevent(struct device_node *node)
+{
+	struct clk *clk;
+	int ret;
+
+	nps_timer0_irq = irq_of_parse_and_map(node, 0);
+	if (nps_timer0_irq <= 0) {
+		pr_err("clockevent: missing irq\n");
+		return -EINVAL;
+	}
+
+	ret = nps_get_timer_clk(node, &nps_timer0_freq, &clk);
+	if (ret)
+		return ret;
+
+	/* Needs apriori irq_set_percpu_devid() done in intc map function */
+	ret = request_percpu_irq(nps_timer0_irq, timer_irq_handler,
+				 "Timer0 (per-cpu-tick)",
+				 &nps_clockevent_device);
+	if (ret) {
+		pr_err("Couldn't request irq\n");
+		clk_disable_unprepare(clk);
+		return ret;
+	}
+
+	ret = cpuhp_setup_state(CPUHP_AP_ARC_TIMER_STARTING,
+				"clockevents/nps:starting",
+				nps_timer_starting_cpu,
+				nps_timer_dying_cpu);
+	if (ret) {
+		pr_err("Failed to setup hotplug state\n");
+		clk_disable_unprepare(clk);
+		free_percpu_irq(nps_timer0_irq, &nps_clockevent_device);
+		return ret;
+	}
+
+	return 0;
+}
+
+TIMER_OF_DECLARE(ezchip_nps400_clk_evt, "ezchip,nps400-timer0",
+		       nps_setup_clockevent);
+#endif /* CONFIG_EZNPS_MTM_EXT */