--- /dev/null
+/*
+ * arch/arm/plat-orion/time.c
+ *
+ * Marvell Orion SoC timer handling.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * Timer 0 is used as free-running clocksource, while timer 1 is
+ * used as clock_event_device.
+ */
+
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/sched_clock.h>
+#include <plat/time.h>
+
+/*
+ * MBus bridge block registers.
+ */
+#define BRIDGE_CAUSE_OFF 0x0110
+#define BRIDGE_MASK_OFF 0x0114
+#define BRIDGE_INT_TIMER0 0x0002
+#define BRIDGE_INT_TIMER1 0x0004
+
+
+/*
+ * Timer block registers.
+ */
+#define TIMER_CTRL_OFF 0x0000
+#define TIMER0_EN 0x0001
+#define TIMER0_RELOAD_EN 0x0002
+#define TIMER1_EN 0x0004
+#define TIMER1_RELOAD_EN 0x0008
+#define TIMER0_RELOAD_OFF 0x0010
+#define TIMER0_VAL_OFF 0x0014
+#define TIMER1_RELOAD_OFF 0x0018
+#define TIMER1_VAL_OFF 0x001c
+
+
+/*
+ * SoC-specific data.
+ */
+static void __iomem *bridge_base;
+static u32 bridge_timer1_clr_mask;
+static void __iomem *timer_base;
+
+
+/*
+ * Number of timer ticks per jiffy.
+ */
+static u32 ticks_per_jiffy;
+
+
+/*
+ * Orion's sched_clock implementation. It has a resolution of
+ * at least 7.5ns (133MHz TCLK).
+ */
+
+static u64 notrace orion_read_sched_clock(void)
+{
+ return ~readl(timer_base + TIMER0_VAL_OFF);
+}
+
+/*
+ * Clockevent handling.
+ */
+static int
+orion_clkevt_next_event(unsigned long delta, struct clock_event_device *dev)
+{
+ unsigned long flags;
+ u32 u;
+
+ if (delta == 0)
+ return -ETIME;
+
+ local_irq_save(flags);
+
+ /*
+ * Clear and enable clockevent timer interrupt.
+ */
+ writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
+
+ u = readl(bridge_base + BRIDGE_MASK_OFF);
+ u |= BRIDGE_INT_TIMER1;
+ writel(u, bridge_base + BRIDGE_MASK_OFF);
+
+ /*
+ * Setup new clockevent timer value.
+ */
+ writel(delta, timer_base + TIMER1_VAL_OFF);
+
+ /*
+ * Enable the timer.
+ */
+ u = readl(timer_base + TIMER_CTRL_OFF);
+ u = (u & ~TIMER1_RELOAD_EN) | TIMER1_EN;
+ writel(u, timer_base + TIMER_CTRL_OFF);
+
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+static void
+orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
+{
+ unsigned long flags;
+ u32 u;
+
+ local_irq_save(flags);
+ if (mode == CLOCK_EVT_MODE_PERIODIC) {
+ /*
+ * Setup timer to fire at 1/HZ intervals.
+ */
+ writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD_OFF);
+ writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL_OFF);
+
+ /*
+ * Enable timer interrupt.
+ */
+ u = readl(bridge_base + BRIDGE_MASK_OFF);
+ writel(u | BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
+
+ /*
+ * Enable timer.
+ */
+ u = readl(timer_base + TIMER_CTRL_OFF);
+ writel(u | TIMER1_EN | TIMER1_RELOAD_EN,
+ timer_base + TIMER_CTRL_OFF);
+ } else {
+ /*
+ * Disable timer.
+ */
+ u = readl(timer_base + TIMER_CTRL_OFF);
+ writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF);
+
+ /*
+ * Disable timer interrupt.
+ */
+ u = readl(bridge_base + BRIDGE_MASK_OFF);
+ writel(u & ~BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
+
+ /*
+ * ACK pending timer interrupt.
+ */
+ writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
+
+ }
+ local_irq_restore(flags);
+}
+
+static struct clock_event_device orion_clkevt = {
+ .name = "orion_tick",
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .rating = 300,
+ .set_next_event = orion_clkevt_next_event,
+ .set_mode = orion_clkevt_mode,
+};
+
+static irqreturn_t orion_timer_interrupt(int irq, void *dev_id)
+{
+ /*
+ * ACK timer interrupt and call event handler.
+ */
+ writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
+ orion_clkevt.event_handler(&orion_clkevt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction orion_timer_irq = {
+ .name = "orion_tick",
+ .flags = IRQF_TIMER,
+ .handler = orion_timer_interrupt
+};
+
+void __init
+orion_time_set_base(void __iomem *_timer_base)
+{
+ timer_base = _timer_base;
+}
+
+void __init
+orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
+ unsigned int irq, unsigned int tclk)
+{
+ u32 u;
+
+ /*
+ * Set SoC-specific data.
+ */
+ bridge_base = _bridge_base;
+ bridge_timer1_clr_mask = _bridge_timer1_clr_mask;
+
+ ticks_per_jiffy = (tclk + HZ/2) / HZ;
+
+ /*
+ * Set scale and timer for sched_clock.
+ */
+ sched_clock_register(orion_read_sched_clock, 32, tclk);
+
+ /*
+ * Setup free-running clocksource timer (interrupts
+ * disabled).
+ */
+ writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
+ writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
+ u = readl(bridge_base + BRIDGE_MASK_OFF);
+ writel(u & ~BRIDGE_INT_TIMER0, bridge_base + BRIDGE_MASK_OFF);
+ u = readl(timer_base + TIMER_CTRL_OFF);
+ writel(u | TIMER0_EN | TIMER0_RELOAD_EN, timer_base + TIMER_CTRL_OFF);
+ clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "orion_clocksource",
+ tclk, 300, 32, clocksource_mmio_readl_down);
+
+ /*
+ * Setup clockevent timer (interrupt-driven).
+ */
+ setup_irq(irq, &orion_timer_irq);
+ orion_clkevt.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&orion_clkevt, tclk, 1, 0xfffffffe);
+}
Code Review / kvmfornfv.git / blobdiff