1 files changed, 148 insertions, 0 deletions
diff --git a/drivers/clocksource/sun4i_timer.c b/drivers/clocksource/sun4i_timer.c
new file mode 100644
index 000000000000..d4674e78ef35
--- /dev/null
+++ b/drivers/clocksource/sun4i_timer.c
@@ -0,0 +1,148 @@
+/*
+ * Allwinner A1X SoCs timer handling.
+ *
+ * Copyright (C) 2012 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * Based on code from
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Benn Huang <benn@allwinnertech.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.
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqreturn.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define TIMER_IRQ_EN_REG	0x00
+#define TIMER_IRQ_EN(val)		(1 << val)
+#define TIMER_IRQ_ST_REG	0x04
+#define TIMER_CTL_REG(val)	(0x10 * val + 0x10)
+#define TIMER_CTL_ENABLE		(1 << 0)
+#define TIMER_CTL_AUTORELOAD		(1 << 1)
+#define TIMER_CTL_ONESHOT		(1 << 7)
+#define TIMER_INTVAL_REG(val)	(0x10 * val + 0x14)
+#define TIMER_CNTVAL_REG(val)	(0x10 * val + 0x18)
+
+#define TIMER_SCAL		16
+
+static void __iomem *timer_base;
+
+static void sun4i_clkevt_mode(enum clock_event_mode mode,
+			      struct clock_event_device *clk)
+{
+	u32 u = readl(timer_base + TIMER_CTL_REG(0));
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		u &= ~(TIMER_CTL_ONESHOT);
+		writel(u | TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG(0));
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+		writel(u | TIMER_CTL_ONESHOT, timer_base + TIMER_CTL_REG(0));
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	default:
+		writel(u & ~(TIMER_CTL_ENABLE), timer_base + TIMER_CTL_REG(0));
+		break;
+	}
+}
+
+static int sun4i_clkevt_next_event(unsigned long evt,
+				   struct clock_event_device *unused)
+{
+	u32 u = readl(timer_base + TIMER_CTL_REG(0));
+	writel(evt, timer_base + TIMER_CNTVAL_REG(0));
+	writel(u | TIMER_CTL_ENABLE | TIMER_CTL_AUTORELOAD,
+	       timer_base + TIMER_CTL_REG(0));
+
+	return 0;
+}
+
+static struct clock_event_device sun4i_clockevent = {
+	.name = "sun4i_tick",
+	.rating = 300,
+	.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_mode = sun4i_clkevt_mode,
+	.set_next_event = sun4i_clkevt_next_event,
+};
+
+
+static irqreturn_t sun4i_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = (struct clock_event_device *)dev_id;
+
+	writel(0x1, timer_base + TIMER_IRQ_ST_REG);
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction sun4i_timer_irq = {
+	.name = "sun4i_timer0",
+	.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+	.handler = sun4i_timer_interrupt,
+	.dev_id = &sun4i_clockevent,
+};
+
+static void __init sun4i_timer_init(struct device_node *node)
+{
+	unsigned long rate = 0;
+	struct clk *clk;
+	int ret, irq;
+	u32 val;
+
+	timer_base = of_iomap(node, 0);
+	if (!timer_base)
+		panic("Can't map registers");
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (irq <= 0)
+		panic("Can't parse IRQ");
+
+	clk = of_clk_get(node, 0);
+	if (IS_ERR(clk))
+		panic("Can't get timer clock");
+
+	rate = clk_get_rate(clk);
+
+	writel(rate / (TIMER_SCAL * HZ),
+	       timer_base + TIMER_INTVAL_REG(0));
+
+	/* set clock source to HOSC, 16 pre-division */
+	val = readl(timer_base + TIMER_CTL_REG(0));
+	val &= ~(0x07 << 4);
+	val &= ~(0x03 << 2);
+	val |= (4 << 4) | (1 << 2);
+	writel(val, timer_base + TIMER_CTL_REG(0));
+
+	/* set mode to auto reload */
+	val = readl(timer_base + TIMER_CTL_REG(0));
+	writel(val | TIMER_CTL_AUTORELOAD, timer_base + TIMER_CTL_REG(0));
+
+	ret = setup_irq(irq, &sun4i_timer_irq);
+	if (ret)
+		pr_warn("failed to setup irq %d\n", irq);
+
+	/* Enable timer0 interrupt */
+	val = readl(timer_base + TIMER_IRQ_EN_REG);
+	writel(val | TIMER_IRQ_EN(0), timer_base + TIMER_IRQ_EN_REG);
+
+	sun4i_clockevent.cpumask = cpumask_of(0);
+
+	clockevents_config_and_register(&sun4i_clockevent, rate / TIMER_SCAL,
+					0x1, 0xff);
+}
+CLOCKSOURCE_OF_DECLARE(sun4i, "allwinner,sun4i-timer",
+		       sun4i_timer_init);