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-rw-r--r--drivers/clocksource/timer-orion.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-orion.c b/drivers/clocksource/timer-orion.c
new file mode 100644
index 000000000..49e86cb70
--- /dev/null
+++ b/drivers/clocksource/timer-orion.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Marvell Orion SoC timer handling.
+ *
+ * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
+ *
+ * Timer 0 is used as free-running clocksource, while timer 1 is
+ * used as clock_event_device.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/spinlock.h>
+#include <linux/sched_clock.h>
+
+#define TIMER_CTRL 0x00
+#define TIMER0_EN BIT(0)
+#define TIMER0_RELOAD_EN BIT(1)
+#define TIMER1_EN BIT(2)
+#define TIMER1_RELOAD_EN BIT(3)
+#define TIMER0_RELOAD 0x10
+#define TIMER0_VAL 0x14
+#define TIMER1_RELOAD 0x18
+#define TIMER1_VAL 0x1c
+
+#define ORION_ONESHOT_MIN 1
+#define ORION_ONESHOT_MAX 0xfffffffe
+
+static void __iomem *timer_base;
+
+static unsigned long notrace orion_read_timer(void)
+{
+ return ~readl(timer_base + TIMER0_VAL);
+}
+
+static struct delay_timer orion_delay_timer = {
+ .read_current_timer = orion_read_timer,
+};
+
+static void orion_delay_timer_init(unsigned long rate)
+{
+ orion_delay_timer.freq = rate;
+ register_current_timer_delay(&orion_delay_timer);
+}
+
+/*
+ * Free-running clocksource handling.
+ */
+static u64 notrace orion_read_sched_clock(void)
+{
+ return ~readl(timer_base + TIMER0_VAL);
+}
+
+/*
+ * Clockevent handling.
+ */
+static u32 ticks_per_jiffy;
+
+static int orion_clkevt_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ /* setup and enable one-shot timer */
+ writel(delta, timer_base + TIMER1_VAL);
+ atomic_io_modify(timer_base + TIMER_CTRL,
+ TIMER1_RELOAD_EN | TIMER1_EN, TIMER1_EN);
+
+ return 0;
+}
+
+static int orion_clkevt_shutdown(struct clock_event_device *dev)
+{
+ /* disable timer */
+ atomic_io_modify(timer_base + TIMER_CTRL,
+ TIMER1_RELOAD_EN | TIMER1_EN, 0);
+ return 0;
+}
+
+static int orion_clkevt_set_periodic(struct clock_event_device *dev)
+{
+ /* setup and enable periodic timer at 1/HZ intervals */
+ writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD);
+ writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL);
+ atomic_io_modify(timer_base + TIMER_CTRL,
+ TIMER1_RELOAD_EN | TIMER1_EN,
+ TIMER1_RELOAD_EN | TIMER1_EN);
+ return 0;
+}
+
+static struct clock_event_device orion_clkevt = {
+ .name = "orion_event",
+ .features = CLOCK_EVT_FEAT_ONESHOT |
+ CLOCK_EVT_FEAT_PERIODIC,
+ .shift = 32,
+ .rating = 300,
+ .set_next_event = orion_clkevt_next_event,
+ .set_state_shutdown = orion_clkevt_shutdown,
+ .set_state_periodic = orion_clkevt_set_periodic,
+ .set_state_oneshot = orion_clkevt_shutdown,
+ .tick_resume = orion_clkevt_shutdown,
+};
+
+static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id)
+{
+ orion_clkevt.event_handler(&orion_clkevt);
+ return IRQ_HANDLED;
+}
+
+static int __init orion_timer_init(struct device_node *np)
+{
+ unsigned long rate;
+ struct clk *clk;
+ int irq, ret;
+
+ /* timer registers are shared with watchdog timer */
+ timer_base = of_iomap(np, 0);
+ if (!timer_base) {
+ pr_err("%pOFn: unable to map resource\n", np);
+ return -ENXIO;
+ }
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk)) {
+ pr_err("%pOFn: unable to get clk\n", np);
+ return PTR_ERR(clk);
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("Failed to prepare clock\n");
+ return ret;
+ }
+
+ /* we are only interested in timer1 irq */
+ irq = irq_of_parse_and_map(np, 1);
+ if (irq <= 0) {
+ pr_err("%pOFn: unable to parse timer1 irq\n", np);
+ ret = -EINVAL;
+ goto out_unprep_clk;
+ }
+
+ rate = clk_get_rate(clk);
+
+ /* setup timer0 as free-running clocksource */
+ writel(~0, timer_base + TIMER0_VAL);
+ writel(~0, timer_base + TIMER0_RELOAD);
+ atomic_io_modify(timer_base + TIMER_CTRL,
+ TIMER0_RELOAD_EN | TIMER0_EN,
+ TIMER0_RELOAD_EN | TIMER0_EN);
+
+ ret = clocksource_mmio_init(timer_base + TIMER0_VAL,
+ "orion_clocksource", rate, 300, 32,
+ clocksource_mmio_readl_down);
+ if (ret) {
+ pr_err("Failed to initialize mmio timer\n");
+ goto out_unprep_clk;
+ }
+
+ sched_clock_register(orion_read_sched_clock, 32, rate);
+
+ /* setup timer1 as clockevent timer */
+ ret = request_irq(irq, orion_clkevt_irq_handler, IRQF_TIMER,
+ "orion_event", NULL);
+ if (ret) {
+ pr_err("%pOFn: unable to setup irq\n", np);
+ goto out_unprep_clk;
+ }
+
+ ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
+ orion_clkevt.cpumask = cpumask_of(0);
+ orion_clkevt.irq = irq;
+ clockevents_config_and_register(&orion_clkevt, rate,
+ ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
+
+
+ orion_delay_timer_init(rate);
+
+ return 0;
+
+out_unprep_clk:
+ clk_disable_unprepare(clk);
+ return ret;
+}
+TIMER_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);