Add PMU-based CPU frequency scaling. This method is used on most Titanium

PowerBooks.

MFC after:	1 month

1 files changed, 222 insertions, 0 deletions

diff --git a/sys/powerpc/cpufreq/pmufreq.c b/sys/powerpc/cpufreq/pmufreq.c
new file mode 100644
index 0000000..d22ff0b
--- /dev/null
+++ b/sys/powerpc/cpufreq/pmufreq.c
@@ -0,0 +1,222 @@
+/*-
+ * Copyright (c) 2011 Justin Hibbits
+ * Copyright (c) 2009 Nathan Whitehorn
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/cpu.h>
+#include <sys/kernel.h>
+#include <sys/limits.h>
+#include <sys/module.h>
+
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/openfirm.h>
+
+#include "cpufreq_if.h"
+#include "powerpc/powermac/pmuvar.h"
+
+struct pmufreq_softc {
+	device_t dev;
+	uint32_t minfreq;
+	uint32_t maxfreq;
+	uint32_t curfreq;
+};
+
+static void	pmufreq_identify(driver_t *driver, device_t parent);
+static int	pmufreq_probe(device_t dev);
+static int	pmufreq_attach(device_t dev);
+static int	pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
+static int	pmufreq_set(device_t dev, const struct cf_setting *set);
+static int	pmufreq_get(device_t dev, struct cf_setting *set);
+static int	pmufreq_type(device_t dev, int *type);
+
+static device_method_t pmufreq_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_identify,	pmufreq_identify),
+	DEVMETHOD(device_probe,		pmufreq_probe),
+	DEVMETHOD(device_attach,	pmufreq_attach),
+
+	/* cpufreq interface */
+	DEVMETHOD(cpufreq_drv_set,	pmufreq_set),
+	DEVMETHOD(cpufreq_drv_get,	pmufreq_get),
+	DEVMETHOD(cpufreq_drv_type,	pmufreq_type),
+	DEVMETHOD(cpufreq_drv_settings,	pmufreq_settings),
+
+	{0, 0}
+};
+
+static driver_t pmufreq_driver = {
+	"pmufreq",
+	pmufreq_methods,
+	sizeof(struct pmufreq_softc)
+};
+
+static devclass_t pmufreq_devclass;
+DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, pmufreq_devclass, 0, 0);
+
+static void
+pmufreq_identify(driver_t *driver, device_t parent)
+{
+	phandle_t node;
+	uint32_t min_freq;
+
+	node = ofw_bus_get_node(parent);
+	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
+		return;
+
+	/* Make sure we're not being doubly invoked. */
+	if (device_find_child(parent, "pmufreq", -1) != NULL)
+		return;
+
+	/*
+	 * We attach a child for every CPU since settings need to
+	 * be performed on every CPU in the SMP case.
+	 */
+	if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
+		device_printf(parent, "add pmufreq child failed\n");
+}
+
+static int
+pmufreq_probe(device_t dev)
+{
+	uint32_t min_freq;
+	struct pmufreq_softc *sc;
+	phandle_t node;
+
+	if (resource_disabled("pmufreq", 0))
+		return (ENXIO);
+
+	sc = device_get_softc(dev);
+	node = ofw_bus_get_node(device_get_parent(dev));
+	/*
+	 * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
+	 * properties of the 'cpu' node.
+	 */
+	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
+		return (ENXIO);
+	device_set_desc(dev, "PMU-based frequency scaling");
+	return (0);
+}
+
+static int
+pmufreq_attach(device_t dev)
+{
+	struct pmufreq_softc *sc;
+	phandle_t node;
+
+	sc = device_get_softc(dev);
+	sc->dev = dev;
+
+	node = ofw_bus_get_node(device_get_parent(dev));
+	OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
+	OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
+	OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
+	sc->minfreq /= 1000000;
+	sc->maxfreq /= 1000000;
+	sc->curfreq /= 1000000;
+
+	cpufreq_register(dev);
+	return (0);
+}
+
+static int
+pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
+{
+	struct pmufreq_softc *sc;
+
+	sc = device_get_softc(dev);
+	if (sets == NULL || count == NULL)
+		return (EINVAL);
+	if (*count < 2)
+		return (E2BIG);
+
+	/* Return a list of valid settings for this driver. */
+	memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
+
+	sets[0].freq = sc->maxfreq; sets[0].dev = dev;
+	sets[1].freq = sc->minfreq; sets[1].dev = dev;
+	/* Set high latency for CPU frequency changes, it's a tedious process. */
+	sets[0].lat = INT_MAX;
+	sets[1].lat = INT_MAX;
+	*count = 2;
+
+	return (0);
+}
+
+static int
+pmufreq_set(device_t dev, const struct cf_setting *set)
+{
+	struct pmufreq_softc *sc;
+	int speed_sel;
+	int error;
+
+	if (set == NULL)
+		return (EINVAL);
+
+	sc = device_get_softc(dev);
+
+	if (set->freq == sc->maxfreq)
+		speed_sel = 0;
+	else
+		speed_sel = 1;
+
+	error = pmu_set_speed(speed_sel);
+	if (error == 0)
+		sc->curfreq = set->freq;
+
+	return error;
+}
+
+static int
+pmufreq_get(device_t dev, struct cf_setting *set)
+{
+	struct pmufreq_softc *sc;
+
+	if (set == NULL)
+		return (EINVAL);
+	sc = device_get_softc(dev);
+
+	set->freq = sc->curfreq;
+	set->dev = dev;
+
+	return (0);
+}
+
+static int
+pmufreq_type(device_t dev, int *type)
+{
+
+	if (type == NULL)
+		return (EINVAL);
+
+	*type = CPUFREQ_TYPE_ABSOLUTE;
+	return (0);
+}
+