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104 lines
2.6 KiB
104 lines
2.6 KiB
/* |
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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 <[email protected]> |
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* Gregory Clement <[email protected]> |
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* Thomas Petazzoni <[email protected]> |
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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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#define pr_fmt(fmt) "mvebu-pmsu: " fmt |
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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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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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if (!of_machine_is_compatible("marvell,armadaxp")) |
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return 0; |
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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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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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of_node_put(np); |
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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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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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clk = clk_get(cpu_dev, NULL); |
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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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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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ret = dev_pm_opp_add(cpu_dev, clk_get_rate(clk) / 2, 0); |
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if (ret) { |
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dev_pm_opp_remove(cpu_dev, clk_get_rate(clk)); |
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clk_put(clk); |
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dev_err(cpu_dev, "Failed to register OPPs\n"); |
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return ret; |
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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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clk_put(clk); |
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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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