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+/*
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+ * CPUFreq support for Armada 370/XP platforms.
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+ *
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+ * Copyright (C) 2012-2016 Marvell
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+ *
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+ * Yehuda Yitschak <yehuday@marvell.com>
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+ * Gregory Clement <gregory.clement@free-electrons.com>
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+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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+ *
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+ * This file is licensed under the terms of the GNU General Public
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+ * License version 2. This program is licensed "as is" without any
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+ * warranty of any kind, whether express or implied.
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+ */
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+
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+#define pr_fmt(fmt) "mvebu-pmsu: " fmt
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+
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+#include <linux/clk.h>
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+#include <linux/cpu.h>
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+#include <linux/init.h>
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+#include <linux/kernel.h>
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+#include <linux/of_address.h>
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+#include <linux/platform_device.h>
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+#include <linux/pm_opp.h>
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+#include <linux/resource.h>
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+
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+static int __init armada_xp_pmsu_cpufreq_init(void)
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+{
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+ struct device_node *np;
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+ struct resource res;
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+ int ret, cpu;
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+
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+ if (!of_machine_is_compatible("marvell,armadaxp"))
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+ return 0;
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+
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+ /*
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+ * In order to have proper cpufreq handling, we need to ensure
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+ * that the Device Tree description of the CPU clock includes
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+ * the definition of the PMU DFS registers. If not, we do not
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+ * register the clock notifier and the cpufreq driver. This
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+ * piece of code is only for compatibility with old Device
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+ * Trees.
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+ */
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+ np = of_find_compatible_node(NULL, NULL, "marvell,armada-xp-cpu-clock");
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+ if (!np)
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+ return 0;
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+
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+ ret = of_address_to_resource(np, 1, &res);
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+ if (ret) {
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+ pr_warn(FW_WARN "not enabling cpufreq, deprecated armada-xp-cpu-clock binding\n");
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+ of_node_put(np);
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+ return 0;
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+ }
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+
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+ of_node_put(np);
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+
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+ /*
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+ * For each CPU, this loop registers the operating points
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+ * supported (which are the nominal CPU frequency and half of
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+ * it), and registers the clock notifier that will take care
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+ * of doing the PMSU part of a frequency transition.
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+ */
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+ for_each_possible_cpu(cpu) {
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+ struct device *cpu_dev;
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+ struct clk *clk;
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+ int ret;
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+
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+ cpu_dev = get_cpu_device(cpu);
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+ if (!cpu_dev) {
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+ pr_err("Cannot get CPU %d\n", cpu);
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+ continue;
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+ }
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+
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+ clk = clk_get(cpu_dev, 0);
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+ if (IS_ERR(clk)) {
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+ pr_err("Cannot get clock for CPU %d\n", cpu);
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+ return PTR_ERR(clk);
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+ }
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+
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+ /*
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+ * In case of a failure of dev_pm_opp_add(), we don't
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+ * bother with cleaning up the registered OPP (there's
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+ * no function to do so), and simply cancel the
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+ * registration of the cpufreq device.
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+ */
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+ ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk), 0);
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+ if (ret) {
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+ clk_put(clk);
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+ return ret;
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+ }
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+
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+ ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk) / 2, 0);
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+ if (ret) {
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+ clk_put(clk);
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+ return ret;
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+ }
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+
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+ ret = dev_pm_opp_set_sharing_cpus(cpu_dev,
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+ cpumask_of(cpu_dev->id));
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+ if (ret)
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+ dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
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+ __func__, ret);
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+ }
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+
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+ platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
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+ return 0;
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+}
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+device_initcall(armada_xp_pmsu_cpufreq_init);
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