Author: jmcneill
Date: Tue Sep 6 20:43:26 2016
New Revision: 305498
URL: https://svnweb.freebsd.org/changeset/base/305498
Log:
Add generic device-tree cpufreq driver.
This driver supports two bindings:
- cpufreq-dt: systems which share clock and voltage across all CPUs
- arm_big_little_dt: systems which share clock and voltage across all
CPUs in a single cluster
Reviewed by: andrew, imp
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D7741
Added:
head/sys/dev/cpufreq/cpufreq_dt.c (contents, props changed)
Added: head/sys/dev/cpufreq/cpufreq_dt.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/dev/cpufreq/cpufreq_dt.c Tue Sep 6 20:43:26 2016
(r305498)
@@ -0,0 +1,360 @@
+/*-
+ * Copyright (c) 2016 Jared McNeill <jmcne...@invisible.ca>
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Generic DT based cpufreq driver
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/bus.h>
+#include <sys/rman.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/cpu.h>
+#include <sys/cpuset.h>
+#include <sys/smp.h>
+
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+
+#include <dev/extres/clk/clk.h>
+#include <dev/extres/regulator/regulator.h>
+
+#include "cpufreq_if.h"
+
+struct cpufreq_dt_opp {
+ uint32_t freq_khz;
+ uint32_t voltage_uv;
+};
+
+struct cpufreq_dt_softc {
+ clk_t clk;
+ regulator_t reg;
+
+ struct cpufreq_dt_opp *opp;
+ ssize_t nopp;
+ int clk_latency;
+
+ cpuset_t cpus;
+};
+
+static void
+cpufreq_dt_notify(device_t dev, uint64_t freq)
+{
+#ifdef __aarch64__
+ struct cpufreq_dt_softc *sc;
+ struct pcpu *pc;
+ int cpu;
+
+ sc = device_get_softc(dev);
+
+ CPU_FOREACH(cpu) {
+ if (CPU_ISSET(cpu, &sc->cpus)) {
+ pc = pcpu_find(cpu);
+ pc->pc_clock = freq;
+ }
+ }
+#endif
+}
+
+static const struct cpufreq_dt_opp *
+cpufreq_dt_find_opp(device_t dev, uint32_t freq_mhz)
+{
+ struct cpufreq_dt_softc *sc;
+ ssize_t n;
+
+ sc = device_get_softc(dev);
+
+ for (n = 0; n < sc->nopp; n++)
+ if (CPUFREQ_CMP(sc->opp[n].freq_khz / 1000, freq_mhz))
+ return (&sc->opp[n]);
+
+ return (NULL);
+}
+
+static void
+cpufreq_dt_opp_to_setting(device_t dev, const struct cpufreq_dt_opp *opp,
+ struct cf_setting *set)
+{
+ struct cpufreq_dt_softc *sc;
+
+ sc = device_get_softc(dev);
+
+ memset(set, 0, sizeof(*set));
+ set->freq = opp->freq_khz / 1000;
+ set->volts = opp->voltage_uv / 1000;
+ set->power = CPUFREQ_VAL_UNKNOWN;
+ set->lat = sc->clk_latency;
+ set->dev = dev;
+}
+
+static int
+cpufreq_dt_get(device_t dev, struct cf_setting *set)
+{
+ struct cpufreq_dt_softc *sc;
+ const struct cpufreq_dt_opp *opp;
+ uint64_t freq;
+
+ sc = device_get_softc(dev);
+
+ if (clk_get_freq(sc->clk, &freq) != 0)
+ return (ENXIO);
+
+ opp = cpufreq_dt_find_opp(dev, freq / 1000000);
+ if (opp == NULL)
+ return (ENOENT);
+
+ cpufreq_dt_opp_to_setting(dev, opp, set);
+
+ return (0);
+}
+
+static int
+cpufreq_dt_set(device_t dev, const struct cf_setting *set)
+{
+ struct cpufreq_dt_softc *sc;
+ const struct cpufreq_dt_opp *opp, *copp;
+ uint64_t freq;
+ int error;
+
+ sc = device_get_softc(dev);
+
+ if (clk_get_freq(sc->clk, &freq) != 0)
+ return (ENXIO);
+
+ copp = cpufreq_dt_find_opp(dev, freq / 1000000);
+ if (copp == NULL)
+ return (ENOENT);
+ opp = cpufreq_dt_find_opp(dev, set->freq);
+ if (opp == NULL)
+ return (EINVAL);
+
+ if (copp->voltage_uv < opp->voltage_uv) {
+ error = regulator_set_voltage(sc->reg, opp->voltage_uv,
+ opp->voltage_uv);
+ if (error != 0)
+ return (ENXIO);
+ }
+
+ error = clk_set_freq(sc->clk, (uint64_t)opp->freq_khz * 1000, 0);
+ if (error != 0) {
+ /* Restore previous voltage (best effort) */
+ (void)regulator_set_voltage(sc->reg, copp->voltage_uv,
+ copp->voltage_uv);
+ return (ENXIO);
+ }
+
+ if (copp->voltage_uv > opp->voltage_uv) {
+ error = regulator_set_voltage(sc->reg, opp->voltage_uv,
+ opp->voltage_uv);
+ if (error != 0) {
+ /* Restore previous CPU frequency (best effort) */
+ (void)clk_set_freq(sc->clk,
+ (uint64_t)copp->freq_khz * 1000, 0);
+ return (ENXIO);
+ }
+ }
+
+ if (clk_get_freq(sc->clk, &freq) == 0)
+ cpufreq_dt_notify(dev, freq);
+
+ return (0);
+}
+
+
+static int
+cpufreq_dt_type(device_t dev, int *type)
+{
+ if (type == NULL)
+ return (EINVAL);
+
+ *type = CPUFREQ_TYPE_ABSOLUTE;
+ return (0);
+}
+
+static int
+cpufreq_dt_settings(device_t dev, struct cf_setting *sets, int *count)
+{
+ struct cpufreq_dt_softc *sc;
+ ssize_t n;
+
+ if (sets == NULL || count == NULL)
+ return (EINVAL);
+
+ sc = device_get_softc(dev);
+
+ if (*count < sc->nopp) {
+ *count = (int)sc->nopp;
+ return (E2BIG);
+ }
+
+ for (n = 0; n < sc->nopp; n++)
+ cpufreq_dt_opp_to_setting(dev, &sc->opp[n], &sets[n]);
+
+ *count = (int)sc->nopp;
+
+ return (0);
+}
+
+static void
+cpufreq_dt_identify(driver_t *driver, device_t parent)
+{
+ phandle_t node;
+
+ /* Properties must be listed under node /cpus/cpu@0 */
+ node = ofw_bus_get_node(parent);
+
+ /* The cpu@0 node must have the following properties */
+ if (!OF_hasprop(node, "operating-points") ||
+ !OF_hasprop(node, "clocks") ||
+ !OF_hasprop(node, "cpu-supply"))
+ return;
+
+ if (device_find_child(parent, "cpufreq_dt", -1) != NULL)
+ return;
+
+ if (BUS_ADD_CHILD(parent, 0, "cpufreq_dt", -1) == NULL)
+ device_printf(parent, "add cpufreq_dt child failed\n");
+}
+
+static int
+cpufreq_dt_probe(device_t dev)
+{
+ phandle_t node;
+
+ node = ofw_bus_get_node(device_get_parent(dev));
+
+ if (!OF_hasprop(node, "operating-points") ||
+ !OF_hasprop(node, "clocks") ||
+ !OF_hasprop(node, "cpu-supply"))
+ return (ENXIO);
+
+ device_set_desc(dev, "Generic cpufreq driver");
+ return (BUS_PROBE_GENERIC);
+}
+
+static int
+cpufreq_dt_attach(device_t dev)
+{
+ struct cpufreq_dt_softc *sc;
+ uint32_t *opp, lat;
+ phandle_t node, cnode;
+ uint64_t freq;
+ ssize_t n;
+ int cpu;
+
+ sc = device_get_softc(dev);
+ node = ofw_bus_get_node(device_get_parent(dev));
+
+ if (regulator_get_by_ofw_property(dev, node,
+ "cpu-supply", &sc->reg) != 0) {
+ device_printf(dev, "no regulator for %s\n",
+ ofw_bus_get_name(device_get_parent(dev)));
+ return (ENXIO);
+ }
+
+ if (clk_get_by_ofw_index(dev, node, 0, &sc->clk) != 0) {
+ device_printf(dev, "no clock for %s\n",
+ ofw_bus_get_name(device_get_parent(dev)));
+ regulator_release(sc->reg);
+ return (ENXIO);
+ }
+
+ sc->nopp = OF_getencprop_alloc(node, "operating-points",
+ sizeof(*sc->opp), (void **)&opp);
+ if (sc->nopp == -1)
+ return (ENXIO);
+ sc->opp = malloc(sizeof(*sc->opp) * sc->nopp, M_DEVBUF, M_WAITOK);
+ for (n = 0; n < sc->nopp; n++) {
+ sc->opp[n].freq_khz = opp[n * 2 + 0];
+ sc->opp[n].voltage_uv = opp[n * 2 + 1];
+
+ if (bootverbose)
+ device_printf(dev, "%u.%03u MHz, %u uV\n",
+ sc->opp[n].freq_khz / 1000,
+ sc->opp[n].freq_khz % 1000,
+ sc->opp[n].voltage_uv);
+ }
+ free(opp, M_OFWPROP);
+
+ if (OF_getencprop(node, "clock-latency", &lat, sizeof(lat)) == -1)
+ sc->clk_latency = CPUFREQ_VAL_UNKNOWN;
+ else
+ sc->clk_latency = (int)lat;
+
+ /*
+ * Find all CPUs that share the same voltage and CPU frequency
+ * controls. Start with the current node and move forward until
+ * the end is reached or a peer has an "operating-points" property.
+ */
+ CPU_ZERO(&sc->cpus);
+ cpu = device_get_unit(device_get_parent(dev));
+ for (cnode = node; cnode > 0; cnode = OF_peer(cnode), cpu++) {
+ if (cnode != node && OF_hasprop(cnode, "operating-points"))
+ break;
+ CPU_SET(cpu, &sc->cpus);
+ }
+
+ if (clk_get_freq(sc->clk, &freq) == 0)
+ cpufreq_dt_notify(dev, freq);
+
+ cpufreq_register(dev);
+
+ return (0);
+}
+
+
+static device_method_t cpufreq_dt_methods[] = {
+ /* Device interface */
+ DEVMETHOD(device_identify, cpufreq_dt_identify),
+ DEVMETHOD(device_probe, cpufreq_dt_probe),
+ DEVMETHOD(device_attach, cpufreq_dt_attach),
+
+ /* cpufreq interface */
+ DEVMETHOD(cpufreq_drv_get, cpufreq_dt_get),
+ DEVMETHOD(cpufreq_drv_set, cpufreq_dt_set),
+ DEVMETHOD(cpufreq_drv_type, cpufreq_dt_type),
+ DEVMETHOD(cpufreq_drv_settings, cpufreq_dt_settings),
+
+ DEVMETHOD_END
+};
+
+static driver_t cpufreq_dt_driver = {
+ "cpufreq_dt",
+ cpufreq_dt_methods,
+ sizeof(struct cpufreq_dt_softc),
+};
+
+static devclass_t cpufreq_dt_devclass;
+
+DRIVER_MODULE(cpufreq_dt, cpu, cpufreq_dt_driver, cpufreq_dt_devclass, 0, 0);
+MODULE_VERSION(cpufreq_dt, 1);
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