diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-09-11 04:34:46 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-09-11 04:34:46 -0300 |
commit | 863981e96738983919de841ec669e157e6bdaeb0 (patch) | |
tree | d6d89a12e7eb8017837c057935a2271290907f76 /drivers/cpufreq/mvebu-cpufreq.c | |
parent | 8dec7c70575785729a6a9e6719a955e9c545bcab (diff) |
Linux-libre 4.7.1-gnupck-4.7.1-gnu
Diffstat (limited to 'drivers/cpufreq/mvebu-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/mvebu-cpufreq.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/cpufreq/mvebu-cpufreq.c b/drivers/cpufreq/mvebu-cpufreq.c new file mode 100644 index 000000000..e920889b9 --- /dev/null +++ b/drivers/cpufreq/mvebu-cpufreq.c @@ -0,0 +1,107 @@ +/* + * CPUFreq support for Armada 370/XP platforms. + * + * Copyright (C) 2012-2016 Marvell + * + * Yehuda Yitschak <yehuday@marvell.com> + * Gregory Clement <gregory.clement@free-electrons.com> + * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#define pr_fmt(fmt) "mvebu-pmsu: " fmt + +#include <linux/clk.h> +#include <linux/cpu.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/resource.h> + +static int __init armada_xp_pmsu_cpufreq_init(void) +{ + struct device_node *np; + struct resource res; + int ret, cpu; + + if (!of_machine_is_compatible("marvell,armadaxp")) + return 0; + + /* + * In order to have proper cpufreq handling, we need to ensure + * that the Device Tree description of the CPU clock includes + * the definition of the PMU DFS registers. If not, we do not + * register the clock notifier and the cpufreq driver. This + * piece of code is only for compatibility with old Device + * Trees. + */ + np = of_find_compatible_node(NULL, NULL, "marvell,armada-xp-cpu-clock"); + if (!np) + return 0; + + ret = of_address_to_resource(np, 1, &res); + if (ret) { + pr_warn(FW_WARN "not enabling cpufreq, deprecated armada-xp-cpu-clock binding\n"); + of_node_put(np); + return 0; + } + + of_node_put(np); + + /* + * For each CPU, this loop registers the operating points + * supported (which are the nominal CPU frequency and half of + * it), and registers the clock notifier that will take care + * of doing the PMSU part of a frequency transition. + */ + for_each_possible_cpu(cpu) { + struct device *cpu_dev; + struct clk *clk; + int ret; + + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) { + pr_err("Cannot get CPU %d\n", cpu); + continue; + } + + clk = clk_get(cpu_dev, 0); + if (IS_ERR(clk)) { + pr_err("Cannot get clock for CPU %d\n", cpu); + return PTR_ERR(clk); + } + + /* + * In case of a failure of dev_pm_opp_add(), we don't + * bother with cleaning up the registered OPP (there's + * no function to do so), and simply cancel the + * registration of the cpufreq device. + */ + ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk), 0); + if (ret) { + clk_put(clk); + return ret; + } + + ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk) / 2, 0); + if (ret) { + clk_put(clk); + return ret; + } + + ret = dev_pm_opp_set_sharing_cpus(cpu_dev, + cpumask_of(cpu_dev->id)); + if (ret) + dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", + __func__, ret); + } + + platform_device_register_simple("cpufreq-dt", -1, NULL, 0); + return 0; +} +device_initcall(armada_xp_pmsu_cpufreq_init); |