1 files changed, 330 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/timer.c b/arch/microblaze/kernel/timer.c
new file mode 100644
index 000000000..26c385582
--- /dev/null
+++ b/arch/microblaze/kernel/timer.c
@@ -0,0 +1,330 @@
+/*
+ * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2012-2013 Xilinx, Inc.
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/sched/clock.h>
+#include <linux/sched_clock.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/timecounter.h>
+#include <asm/cpuinfo.h>
+
+static void __iomem *timer_baseaddr;
+
+static unsigned int freq_div_hz;
+static unsigned int timer_clock_freq;
+
+#define TCSR0	(0x00)
+#define TLR0	(0x04)
+#define TCR0	(0x08)
+#define TCSR1	(0x10)
+#define TLR1	(0x14)
+#define TCR1	(0x18)
+
+#define TCSR_MDT	(1<<0)
+#define TCSR_UDT	(1<<1)
+#define TCSR_GENT	(1<<2)
+#define TCSR_CAPT	(1<<3)
+#define TCSR_ARHT	(1<<4)
+#define TCSR_LOAD	(1<<5)
+#define TCSR_ENIT	(1<<6)
+#define TCSR_ENT	(1<<7)
+#define TCSR_TINT	(1<<8)
+#define TCSR_PWMA	(1<<9)
+#define TCSR_ENALL	(1<<10)
+
+static unsigned int (*read_fn)(void __iomem *);
+static void (*write_fn)(u32, void __iomem *);
+
+static void timer_write32(u32 val, void __iomem *addr)
+{
+	iowrite32(val, addr);
+}
+
+static unsigned int timer_read32(void __iomem *addr)
+{
+	return ioread32(addr);
+}
+
+static void timer_write32_be(u32 val, void __iomem *addr)
+{
+	iowrite32be(val, addr);
+}
+
+static unsigned int timer_read32_be(void __iomem *addr)
+{
+	return ioread32be(addr);
+}
+
+static inline void xilinx_timer0_stop(void)
+{
+	write_fn(read_fn(timer_baseaddr + TCSR0) & ~TCSR_ENT,
+		 timer_baseaddr + TCSR0);
+}
+
+static inline void xilinx_timer0_start_periodic(unsigned long load_val)
+{
+	if (!load_val)
+		load_val = 1;
+	/* loading value to timer reg */
+	write_fn(load_val, timer_baseaddr + TLR0);
+
+	/* load the initial value */
+	write_fn(TCSR_LOAD, timer_baseaddr + TCSR0);
+
+	/* see timer data sheet for detail
+	 * !ENALL - don't enable 'em all
+	 * !PWMA - disable pwm
+	 * TINT - clear interrupt status
+	 * ENT- enable timer itself
+	 * ENIT - enable interrupt
+	 * !LOAD - clear the bit to let go
+	 * ARHT - auto reload
+	 * !CAPT - no external trigger
+	 * !GENT - no external signal
+	 * UDT - set the timer as down counter
+	 * !MDT0 - generate mode
+	 */
+	write_fn(TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT,
+		 timer_baseaddr + TCSR0);
+}
+
+static inline void xilinx_timer0_start_oneshot(unsigned long load_val)
+{
+	if (!load_val)
+		load_val = 1;
+	/* loading value to timer reg */
+	write_fn(load_val, timer_baseaddr + TLR0);
+
+	/* load the initial value */
+	write_fn(TCSR_LOAD, timer_baseaddr + TCSR0);
+
+	write_fn(TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT,
+		 timer_baseaddr + TCSR0);
+}
+
+static int xilinx_timer_set_next_event(unsigned long delta,
+					struct clock_event_device *dev)
+{
+	pr_debug("%s: next event, delta %x\n", __func__, (u32)delta);
+	xilinx_timer0_start_oneshot(delta);
+	return 0;
+}
+
+static int xilinx_timer_shutdown(struct clock_event_device *evt)
+{
+	pr_info("%s\n", __func__);
+	xilinx_timer0_stop();
+	return 0;
+}
+
+static int xilinx_timer_set_periodic(struct clock_event_device *evt)
+{
+	pr_info("%s\n", __func__);
+	xilinx_timer0_start_periodic(freq_div_hz);
+	return 0;
+}
+
+static struct clock_event_device clockevent_xilinx_timer = {
+	.name			= "xilinx_clockevent",
+	.features		= CLOCK_EVT_FEAT_ONESHOT |
+				  CLOCK_EVT_FEAT_PERIODIC,
+	.shift			= 8,
+	.rating			= 300,
+	.set_next_event		= xilinx_timer_set_next_event,
+	.set_state_shutdown	= xilinx_timer_shutdown,
+	.set_state_periodic	= xilinx_timer_set_periodic,
+};
+
+static inline void timer_ack(void)
+{
+	write_fn(read_fn(timer_baseaddr + TCSR0), timer_baseaddr + TCSR0);
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &clockevent_xilinx_timer;
+	timer_ack();
+	evt->event_handler(evt);
+	return IRQ_HANDLED;
+}
+
+static __init int xilinx_clockevent_init(void)
+{
+	clockevent_xilinx_timer.mult =
+		div_sc(timer_clock_freq, NSEC_PER_SEC,
+				clockevent_xilinx_timer.shift);
+	clockevent_xilinx_timer.max_delta_ns =
+		clockevent_delta2ns((u32)~0, &clockevent_xilinx_timer);
+	clockevent_xilinx_timer.max_delta_ticks = (u32)~0;
+	clockevent_xilinx_timer.min_delta_ns =
+		clockevent_delta2ns(1, &clockevent_xilinx_timer);
+	clockevent_xilinx_timer.min_delta_ticks = 1;
+	clockevent_xilinx_timer.cpumask = cpumask_of(0);
+	clockevents_register_device(&clockevent_xilinx_timer);
+
+	return 0;
+}
+
+static u64 xilinx_clock_read(void)
+{
+	return read_fn(timer_baseaddr + TCR1);
+}
+
+static u64 xilinx_read(struct clocksource *cs)
+{
+	/* reading actual value of timer 1 */
+	return (u64)xilinx_clock_read();
+}
+
+static struct timecounter xilinx_tc = {
+	.cc = NULL,
+};
+
+static u64 xilinx_cc_read(const struct cyclecounter *cc)
+{
+	return xilinx_read(NULL);
+}
+
+static struct cyclecounter xilinx_cc = {
+	.read = xilinx_cc_read,
+	.mask = CLOCKSOURCE_MASK(32),
+	.shift = 8,
+};
+
+static int __init init_xilinx_timecounter(void)
+{
+	xilinx_cc.mult = div_sc(timer_clock_freq, NSEC_PER_SEC,
+				xilinx_cc.shift);
+
+	timecounter_init(&xilinx_tc, &xilinx_cc, sched_clock());
+
+	return 0;
+}
+
+static struct clocksource clocksource_microblaze = {
+	.name		= "xilinx_clocksource",
+	.rating		= 300,
+	.read		= xilinx_read,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init xilinx_clocksource_init(void)
+{
+	int ret;
+
+	ret = clocksource_register_hz(&clocksource_microblaze,
+				      timer_clock_freq);
+	if (ret) {
+		pr_err("failed to register clocksource");
+		return ret;
+	}
+
+	/* stop timer1 */
+	write_fn(read_fn(timer_baseaddr + TCSR1) & ~TCSR_ENT,
+		 timer_baseaddr + TCSR1);
+	/* start timer1 - up counting without interrupt */
+	write_fn(TCSR_TINT|TCSR_ENT|TCSR_ARHT, timer_baseaddr + TCSR1);
+
+	/* register timecounter - for ftrace support */
+	return init_xilinx_timecounter();
+}
+
+static int __init xilinx_timer_init(struct device_node *timer)
+{
+	struct clk *clk;
+	static int initialized;
+	u32 irq;
+	u32 timer_num = 1;
+	int ret;
+
+	/* If this property is present, the device is a PWM and not a timer */
+	if (of_property_read_bool(timer, "#pwm-cells"))
+		return 0;
+
+	if (initialized)
+		return -EINVAL;
+
+	initialized = 1;
+
+	timer_baseaddr = of_iomap(timer, 0);
+	if (!timer_baseaddr) {
+		pr_err("ERROR: invalid timer base address\n");
+		return -ENXIO;
+	}
+
+	write_fn = timer_write32;
+	read_fn = timer_read32;
+
+	write_fn(TCSR_MDT, timer_baseaddr + TCSR0);
+	if (!(read_fn(timer_baseaddr + TCSR0) & TCSR_MDT)) {
+		write_fn = timer_write32_be;
+		read_fn = timer_read32_be;
+	}
+
+	irq = irq_of_parse_and_map(timer, 0);
+	if (irq <= 0) {
+		pr_err("Failed to parse and map irq");
+		return -EINVAL;
+	}
+
+	of_property_read_u32(timer, "xlnx,one-timer-only", &timer_num);
+	if (timer_num) {
+		pr_err("Please enable two timers in HW\n");
+		return -EINVAL;
+	}
+
+	pr_info("%pOF: irq=%d\n", timer, irq);
+
+	clk = of_clk_get(timer, 0);
+	if (IS_ERR(clk)) {
+		pr_err("ERROR: timer CCF input clock not found\n");
+		/* If there is clock-frequency property than use it */
+		of_property_read_u32(timer, "clock-frequency",
+				    &timer_clock_freq);
+	} else {
+		timer_clock_freq = clk_get_rate(clk);
+	}
+
+	if (!timer_clock_freq) {
+		pr_err("ERROR: Using CPU clock frequency\n");
+		timer_clock_freq = cpuinfo.cpu_clock_freq;
+	}
+
+	freq_div_hz = timer_clock_freq / HZ;
+
+	ret = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer",
+			  &clockevent_xilinx_timer);
+	if (ret) {
+		pr_err("Failed to setup IRQ");
+		return ret;
+	}
+
+	ret = xilinx_clocksource_init();
+	if (ret)
+		return ret;
+
+	ret = xilinx_clockevent_init();
+	if (ret)
+		return ret;
+
+	sched_clock_register(xilinx_clock_read, 32, timer_clock_freq);
+
+	return 0;
+}
+
+TIMER_OF_DECLARE(xilinx_timer, "xlnx,xps-timer-1.00.a",
+		       xilinx_timer_init);