Initial import

1 files changed, 180 insertions, 0 deletions

diff --git a/drivers/clocksource/rockchip_timer.c b/drivers/clocksource/rockchip_timer.c
new file mode 100644
index 000000000..a35993baf
--- /dev/null
+++ b/drivers/clocksource/rockchip_timer.c
@@ -0,0 +1,180 @@
+/*
+ * Rockchip timer support
+ *
+ * Copyright (C) Daniel Lezcano <daniel.lezcano@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define TIMER_NAME "rk_timer"
+
+#define TIMER_LOAD_COUNT0 0x00
+#define TIMER_LOAD_COUNT1 0x04
+#define TIMER_CONTROL_REG 0x10
+#define TIMER_INT_STATUS 0x18
+
+#define TIMER_DISABLE 0x0
+#define TIMER_ENABLE 0x1
+#define TIMER_MODE_FREE_RUNNING (0 << 1)
+#define TIMER_MODE_USER_DEFINED_COUNT (1 << 1)
+#define TIMER_INT_UNMASK (1 << 2)
+
+struct bc_timer {
+	struct clock_event_device ce;
+	void __iomem *base;
+	u32 freq;
+};
+
+static struct bc_timer bc_timer;
+
+static inline struct bc_timer *rk_timer(struct clock_event_device *ce)
+{
+	return container_of(ce, struct bc_timer, ce);
+}
+
+static inline void __iomem *rk_base(struct clock_event_device *ce)
+{
+	return rk_timer(ce)->base;
+}
+
+static inline void rk_timer_disable(struct clock_event_device *ce)
+{
+	writel_relaxed(TIMER_DISABLE, rk_base(ce) + TIMER_CONTROL_REG);
+	dsb();
+}
+
+static inline void rk_timer_enable(struct clock_event_device *ce, u32 flags)
+{
+	writel_relaxed(TIMER_ENABLE | TIMER_INT_UNMASK | flags,
+		       rk_base(ce) + TIMER_CONTROL_REG);
+	dsb();
+}
+
+static void rk_timer_update_counter(unsigned long cycles,
+				    struct clock_event_device *ce)
+{
+	writel_relaxed(cycles, rk_base(ce) + TIMER_LOAD_COUNT0);
+	writel_relaxed(0, rk_base(ce) + TIMER_LOAD_COUNT1);
+	dsb();
+}
+
+static void rk_timer_interrupt_clear(struct clock_event_device *ce)
+{
+	writel_relaxed(1, rk_base(ce) + TIMER_INT_STATUS);
+	dsb();
+}
+
+static inline int rk_timer_set_next_event(unsigned long cycles,
+					  struct clock_event_device *ce)
+{
+	rk_timer_disable(ce);
+	rk_timer_update_counter(cycles, ce);
+	rk_timer_enable(ce, TIMER_MODE_USER_DEFINED_COUNT);
+	return 0;
+}
+
+static inline void rk_timer_set_mode(enum clock_event_mode mode,
+				     struct clock_event_device *ce)
+{
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		rk_timer_disable(ce);
+		rk_timer_update_counter(rk_timer(ce)->freq / HZ - 1, ce);
+		rk_timer_enable(ce, TIMER_MODE_FREE_RUNNING);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_RESUME:
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		rk_timer_disable(ce);
+		break;
+	}
+}
+
+static irqreturn_t rk_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *ce = dev_id;
+
+	rk_timer_interrupt_clear(ce);
+
+	if (ce->mode == CLOCK_EVT_MODE_ONESHOT)
+		rk_timer_disable(ce);
+
+	ce->event_handler(ce);
+
+	return IRQ_HANDLED;
+}
+
+static void __init rk_timer_init(struct device_node *np)
+{
+	struct clock_event_device *ce = &bc_timer.ce;
+	struct clk *timer_clk;
+	struct clk *pclk;
+	int ret, irq;
+
+	bc_timer.base = of_iomap(np, 0);
+	if (!bc_timer.base) {
+		pr_err("Failed to get base address for '%s'\n", TIMER_NAME);
+		return;
+	}
+
+	pclk = of_clk_get_by_name(np, "pclk");
+	if (IS_ERR(pclk)) {
+		pr_err("Failed to get pclk for '%s'\n", TIMER_NAME);
+		return;
+	}
+
+	if (clk_prepare_enable(pclk)) {
+		pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME);
+		return;
+	}
+
+	timer_clk = of_clk_get_by_name(np, "timer");
+	if (IS_ERR(timer_clk)) {
+		pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME);
+		return;
+	}
+
+	if (clk_prepare_enable(timer_clk)) {
+		pr_err("Failed to enable timer clock\n");
+		return;
+	}
+
+	bc_timer.freq = clk_get_rate(timer_clk);
+
+	irq = irq_of_parse_and_map(np, 0);
+	if (irq == NO_IRQ) {
+		pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME);
+		return;
+	}
+
+	ce->name = TIMER_NAME;
+	ce->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+	ce->set_next_event = rk_timer_set_next_event;
+	ce->set_mode = rk_timer_set_mode;
+	ce->irq = irq;
+	ce->cpumask = cpumask_of(0);
+	ce->rating = 250;
+
+	rk_timer_interrupt_clear(ce);
+	rk_timer_disable(ce);
+
+	ret = request_irq(irq, rk_timer_interrupt, IRQF_TIMER, TIMER_NAME, ce);
+	if (ret) {
+		pr_err("Failed to initialize '%s': %d\n", TIMER_NAME, ret);
+		return;
+	}
+
+	clockevents_config_and_register(ce, bc_timer.freq, 1, UINT_MAX);
+}
+CLOCKSOURCE_OF_DECLARE(rk_timer, "rockchip,rk3288-timer", rk_timer_init);