--- /dev/null
+/*
+ * Marvell Armada 370/XP SoC timer handling.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Lior Amsalem <alior@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * 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/init.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <asm/sched_clock.h>
+
+/*
+ * Timer block registers.
+ */
+#define TIMER_CTRL_OFF 0x0000
+#define TIMER0_EN 0x0001
+#define TIMER0_RELOAD_EN 0x0002
+#define TIMER0_25MHZ 0x0800
+#define TIMER0_DIV(div) ((div) << 19)
+#define TIMER1_EN 0x0004
+#define TIMER1_RELOAD_EN 0x0008
+#define TIMER1_25MHZ 0x1000
+#define TIMER1_DIV(div) ((div) << 22)
+#define TIMER_EVENTS_STATUS 0x0004
+#define TIMER0_CLR_MASK (~0x1)
+#define TIMER1_CLR_MASK (~0x100)
+#define TIMER0_RELOAD_OFF 0x0010
+#define TIMER0_VAL_OFF 0x0014
+#define TIMER1_RELOAD_OFF 0x0018
+#define TIMER1_VAL_OFF 0x001c
+
+/* Global timers are connected to the coherency fabric clock, and the
+ below divider reduces their incrementing frequency. */
+#define TIMER_DIVIDER_SHIFT 5
+#define TIMER_DIVIDER (1 << TIMER_DIVIDER_SHIFT)
+
+/*
+ * SoC-specific data.
+ */
+static void __iomem *timer_base;
+static int timer_irq;
+
+/*
+ * Number of timer ticks per jiffy.
+ */
+static u32 ticks_per_jiffy;
+
+static u32 notrace armada_370_xp_read_sched_clock(void)
+{
+ return ~readl(timer_base + TIMER0_VAL_OFF);
+}
+
+/*
+ * Clockevent handling.
+ */
+static int
+armada_370_xp_clkevt_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ u32 u;
+
+ /*
+ * Clear clockevent timer interrupt.
+ */
+ writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
+
+ /*
+ * 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 |
+ TIMER1_DIV(TIMER_DIVIDER_SHIFT));
+ writel(u, timer_base + TIMER_CTRL_OFF);
+
+ return 0;
+}
+
+static void
+armada_370_xp_clkevt_mode(enum clock_event_mode mode,
+ struct clock_event_device *dev)
+{
+ u32 u;
+
+ 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.
+ */
+ u = readl(timer_base + TIMER_CTRL_OFF);
+
+ writel((u | TIMER1_EN | TIMER1_RELOAD_EN |
+ TIMER1_DIV(TIMER_DIVIDER_SHIFT)),
+ timer_base + TIMER_CTRL_OFF);
+ } else {
+ /*
+ * Disable timer.
+ */
+ u = readl(timer_base + TIMER_CTRL_OFF);
+ writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF);
+
+ /*
+ * ACK pending timer interrupt.
+ */
+ writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
+
+ }
+}
+
+static struct clock_event_device armada_370_xp_clkevt = {
+ .name = "armada_370_xp_tick",
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .shift = 32,
+ .rating = 300,
+ .set_next_event = armada_370_xp_clkevt_next_event,
+ .set_mode = armada_370_xp_clkevt_mode,
+};
+
+static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
+{
+ /*
+ * ACK timer interrupt and call event handler.
+ */
+
+ writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
+ armada_370_xp_clkevt.event_handler(&armada_370_xp_clkevt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction armada_370_xp_timer_irq = {
+ .name = "armada_370_xp_tick",
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .handler = armada_370_xp_timer_interrupt
+};
+
+void __init armada_370_xp_timer_init(void)
+{
+ u32 u;
+ struct device_node *np;
+ unsigned int timer_clk;
+ int ret;
+ np = of_find_compatible_node(NULL, NULL, "marvell,armada-370-xp-timer");
+ timer_base = of_iomap(np, 0);
+ WARN_ON(!timer_base);
+
+ if (of_find_property(np, "marvell,timer-25Mhz", NULL)) {
+ /* The fixed 25MHz timer is available so let's use it */
+ u = readl(timer_base + TIMER_CTRL_OFF);
+ writel(u | TIMER0_25MHZ | TIMER1_25MHZ,
+ timer_base + TIMER_CTRL_OFF);
+ timer_clk = 25000000;
+ } else {
+ u32 clk = 0;
+ ret = of_property_read_u32(np, "clock-frequency", &clk);
+ WARN_ON(!clk || ret < 0);
+ u = readl(timer_base + TIMER_CTRL_OFF);
+ writel(u & ~(TIMER0_25MHZ | TIMER1_25MHZ),
+ timer_base + TIMER_CTRL_OFF);
+ timer_clk = clk / TIMER_DIVIDER;
+ }
+
+ /* We use timer 0 as clocksource, and timer 1 for
+ clockevents */
+ timer_irq = irq_of_parse_and_map(np, 1);
+
+ ticks_per_jiffy = (timer_clk + HZ / 2) / HZ;
+
+ /*
+ * Set scale and timer for sched_clock.
+ */
+ setup_sched_clock(armada_370_xp_read_sched_clock, 32, timer_clk);
+
+ /*
+ * Setup free-running clocksource timer (interrupts
+ * disabled).
+ */
+ writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
+ writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
+
+ u = readl(timer_base + TIMER_CTRL_OFF);
+
+ writel((u | TIMER0_EN | TIMER0_RELOAD_EN |
+ TIMER0_DIV(TIMER_DIVIDER_SHIFT)), timer_base + TIMER_CTRL_OFF);
+
+ clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
+ "armada_370_xp_clocksource",
+ timer_clk, 300, 32, clocksource_mmio_readl_down);
+
+ /*
+ * Setup clockevent timer (interrupt-driven).
+ */
+ setup_irq(timer_irq, &armada_370_xp_timer_irq);
+ armada_370_xp_clkevt.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&armada_370_xp_clkevt,
+ timer_clk, 1, 0xfffffffe);
+}
+
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / commitdiff