Add ARM Generic Timer driver.

Submitted by:	Ruslan Bukin <br@bsdpad.com>

1 files changed, 374 insertions, 0 deletions

diff --git a/sys/arm/arm/generic_timer.c b/sys/arm/arm/generic_timer.c
new file mode 100644
index 0000000..02b326d
--- /dev/null
+++ b/sys/arm/arm/generic_timer.c
@@ -0,0 +1,374 @@
+/*-
+ * Copyright (c) 2011 The FreeBSD Foundation
+ * Copyright (c) 2013 Ruslan Bukin <br@bsdpad.com>
+ * All rights reserved.
+ *
+ * Based on mpcore_timer.c developed by Ben Gray <ben.r.gray@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the company nor the name of the author may be used to
+ *    endorse or promote products derived from this software without specific
+ *    prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/**
+ *      Cortex-A15 (and probably A7) Generic Timer
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/malloc.h>
+#include <sys/rman.h>
+#include <sys/timeet.h>
+#include <sys/timetc.h>
+#include <sys/watchdog.h>
+#include <machine/bus.h>
+#include <machine/cpu.h>
+#include <machine/frame.h>
+#include <machine/intr.h>
+
+#include <dev/fdt/fdt_common.h>
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+
+#include <machine/bus.h>
+#include <machine/fdt.h>
+
+#define	GENERIC_TIMER_CTRL_ENABLE	(1 << 0)
+#define	GENERIC_TIMER_CTRL_INT_MASK	(1 << 1)
+#define	GENERIC_TIMER_CTRL_INT_STAT	(1 << 2)
+#define	GENERIC_TIMER_REG_CTRL		0
+#define	GENERIC_TIMER_REG_TVAL		1
+
+#define	CNTPSIRQ	29
+
+struct arm_tmr_softc {
+	struct resource		*irq_res;
+	uint32_t		clkfreq;
+	struct eventtimer	et;
+};
+
+static struct arm_tmr_softc *arm_tmr_sc = NULL;
+
+static timecounter_get_t arm_tmr_get_timecount;
+
+static struct timecounter arm_tmr_timecount = {
+	.tc_name           = "ARM MPCore Timecounter",
+	.tc_get_timecount  = arm_tmr_get_timecount,
+	.tc_poll_pps       = NULL,
+	.tc_counter_mask   = ~0u,
+	.tc_frequency      = 0,
+	.tc_quality        = 1000,
+};
+
+static inline int
+get_freq(void)
+{
+	uint32_t val;
+
+	__asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
+
+	return (val);
+}
+
+static inline int
+set_freq(uint32_t val)
+{
+
+	__asm volatile("mcr p15, 0, %[val], c14, c0, 0" : :
+	    [val] "r" (val));
+	isb();
+
+	return (val);
+}
+
+
+static inline long
+get_cntpct(void)
+{
+	uint64_t val;
+
+	__asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (val));
+
+	return (val);
+}
+
+static inline int
+set_ctrl(uint32_t val)
+{
+
+	__asm volatile("mcr p15, 0, %[val], c14, c2, 1" : :
+	    [val] "r" (val));
+	isb();
+
+	return (0);
+}
+
+static inline int
+set_tval(uint32_t val)
+{
+
+	__asm volatile("mcr p15, 0, %[val], c14, c2, 0" : :
+	    [val] "r" (val));
+	isb();
+
+	return (0);
+}
+
+static inline int
+get_ctrl(void)
+{
+	uint32_t val;
+
+	__asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
+
+	return (val);
+}
+
+static inline int
+get_tval(void)
+{
+	uint32_t val;
+
+	__asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
+
+	return (val);
+}
+
+static inline void
+disable_user_access(void)
+{
+	uint32_t cntkctl;
+
+	__asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));
+	cntkctl &= ~((3 << 8) | (7 << 0));
+	__asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
+	isb();
+}
+
+static unsigned
+arm_tmr_get_timecount(struct timecounter *tc)
+{
+
+	return (get_cntpct());
+}
+
+static int
+arm_tmr_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
+{
+	struct arm_tmr_softc *sc;
+	int counts, ctrl;
+
+	sc = (struct arm_tmr_softc *)et->et_priv;
+
+	if (first != 0) {
+		counts = ((uint32_t)et->et_frequency * first) >> 32;
+		ctrl = get_ctrl();
+		ctrl &= ~GENERIC_TIMER_CTRL_INT_MASK;
+		ctrl |= GENERIC_TIMER_CTRL_ENABLE;
+		set_tval(counts);
+		set_ctrl(ctrl);
+		return (0);
+	}
+
+	return (EINVAL);
+
+}
+
+static int
+arm_tmr_stop(struct eventtimer *et)
+{
+	int ctrl;
+
+	ctrl = get_ctrl();
+	ctrl &= GENERIC_TIMER_CTRL_ENABLE;
+	set_ctrl(ctrl);
+
+	return (0);
+}
+
+static int
+arm_tmr_intr(void *arg)
+{
+	struct arm_tmr_softc *sc;
+	int ctrl;
+
+	sc = (struct arm_tmr_softc *)arg;
+	ctrl = get_ctrl();
+	if (ctrl & GENERIC_TIMER_CTRL_INT_STAT) {
+	        ctrl |= GENERIC_TIMER_CTRL_INT_MASK;
+		set_ctrl(ctrl);
+	}
+
+	if (sc->et.et_active)
+		sc->et.et_event_cb(&sc->et, sc->et.et_arg);
+
+	return (FILTER_HANDLED);
+}
+
+static int
+arm_tmr_probe(device_t dev)
+{
+
+	if (!ofw_bus_is_compatible(dev, "arm,armv7-timer"))
+		return (ENXIO);
+
+	device_set_desc(dev, "ARMv7 Generic Timer");
+	return (BUS_PROBE_DEFAULT);
+}
+
+
+static int
+arm_tmr_attach(device_t dev)
+{
+	struct arm_tmr_softc *sc;
+	phandle_t node;
+	pcell_t clock;
+	void *ihl;
+	int rid;
+	int error;
+
+	sc = device_get_softc(dev);
+	if (arm_tmr_sc)
+		return (ENXIO);
+
+	/* Get the base clock frequency */
+	node = ofw_bus_get_node(dev);
+	error = OF_getprop(node, "clock-frequency", &clock, sizeof(clock));
+	if (error <= 0) {
+		device_printf(dev, "missing clock-frequency "
+		    "attribute in FDT\n");
+		return (ENXIO);
+	}
+	sc->clkfreq = fdt32_to_cpu(clock);
+
+	rid = 0;
+	sc->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &rid,
+	    CNTPSIRQ, CNTPSIRQ, 1, RF_SHAREABLE | RF_ACTIVE);
+
+	arm_tmr_sc = sc;
+
+	/* Setup and enable the timer */
+	if (bus_setup_intr(dev, sc->irq_res, INTR_TYPE_CLK, arm_tmr_intr,
+		NULL, sc, &ihl) != 0) {
+		bus_release_resource(dev, SYS_RES_IRQ, rid, sc->irq_res);
+		device_printf(dev, "Unable to setup the CLK irq handler.\n");
+		return (ENXIO);
+	}
+
+	set_freq(sc->clkfreq);
+	disable_user_access();
+
+        arm_tmr_timecount.tc_frequency = sc->clkfreq;
+	tc_init(&arm_tmr_timecount);
+
+	sc->et.et_name = "ARM MPCore Eventtimer";
+	sc->et.et_flags = ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU;
+	sc->et.et_quality = 1000;
+
+	sc->et.et_frequency = sc->clkfreq;
+	sc->et.et_min_period = (0x00000002LLU << 32) / sc->et.et_frequency;
+	sc->et.et_max_period = (0xfffffffeLLU << 32) / sc->et.et_frequency;
+	sc->et.et_start = arm_tmr_start;
+	sc->et.et_stop = arm_tmr_stop;
+	sc->et.et_priv = sc;
+	et_register(&sc->et);
+
+	return (0);
+}
+
+static device_method_t arm_tmr_methods[] = {
+	DEVMETHOD(device_probe,		arm_tmr_probe),
+	DEVMETHOD(device_attach,	arm_tmr_attach),
+	{ 0, 0 }
+};
+
+static driver_t arm_tmr_driver = {
+	"generic_timer",
+	arm_tmr_methods,
+	sizeof(struct arm_tmr_softc),
+};
+
+static devclass_t arm_tmr_devclass;
+
+DRIVER_MODULE(timer, simplebus, arm_tmr_driver, arm_tmr_devclass, 0, 0);
+
+void
+cpu_initclocks(void)
+{
+
+	if (PCPU_GET(cpuid) == 0)
+		cpu_initclocks_bsp();
+	else
+		cpu_initclocks_ap();
+}
+
+void
+DELAY(int usec)
+{
+	int32_t counts, counts_per_usec;
+	uint32_t first, last;
+
+	/*
+	 * Check the timers are setup, if not just
+	 * use a for loop for the meantime
+         */
+	if (arm_tmr_sc == NULL) {
+		for (; usec > 0; usec--)
+			for (counts = 200; counts > 0; counts--)
+				/*
+				 * Prevent gcc from optimizing
+				 * out the loop
+				 */
+				cpufunc_nullop();
+		return;
+	}
+
+	/* Get the number of times to count */
+        counts_per_usec = ((arm_tmr_timecount.tc_frequency / 1000000) + 1);
+
+	/*
+	 * Clamp the timeout at a maximum value (about 32 seconds with
+	 * a 66MHz clock). *Nobody* should be delay()ing for anywhere
+	 * near that length of time and if they are, they should be hung
+	 * out to dry.
+	 */
+	if (usec >= (0x80000000U / counts_per_usec))
+		counts = (0x80000000U / counts_per_usec) - 1;
+	else
+		counts = usec * counts_per_usec;
+
+	first = get_cntpct();
+
+	while (counts > 0) {
+		last = get_cntpct();
+		counts -= (int32_t)(last - first);
+		first = last;
+	}
+}