summaryrefslogtreecommitdiffstats
path: root/drivers/clocksource/timer-nps.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/clocksource/timer-nps.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/clocksource/timer-nps.c')
-rw-r--r--drivers/clocksource/timer-nps.c284
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 */