--- /dev/null
+From 5cf343c60d7557aefb468603065cac5062f11b8d Mon Sep 17 00:00:00 2001
+From: Stephen Boyd <sboyd@codeaurora.org>
+Date: Fri, 30 May 2014 16:36:11 -0700
+Subject: [PATCH 172/182] cpufreq: Add a cpufreq-krait based on cpufreq-cpu0
+
+Krait processors have individual clocks for each CPU that can
+scale independently from one another. cpufreq-cpu0 is fairly
+close to this, but assumes that there is only one clock for all
+CPUs. Add a driver to support the Krait configuration.
+
+TODO: Merge into cpufreq-cpu0? Or make generic?
+
+Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
+---
+ drivers/cpufreq/Kconfig | 13 +++
+ drivers/cpufreq/Makefile | 1 +
+ drivers/cpufreq/cpufreq-krait.c | 190 +++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 204 insertions(+)
+ create mode 100644 drivers/cpufreq/cpufreq-krait.c
+
+diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
+index 4b029c0..4051528 100644
+--- a/drivers/cpufreq/Kconfig
++++ b/drivers/cpufreq/Kconfig
+@@ -194,6 +194,19 @@ config GENERIC_CPUFREQ_CPU0
+
+ If in doubt, say N.
+
++config GENERIC_CPUFREQ_KRAIT
++ tristate "Krait cpufreq driver"
++ depends on HAVE_CLK && OF
++ # if CPU_THERMAL is on and THERMAL=m, CPU0 cannot be =y:
++ depends on !CPU_THERMAL || THERMAL
++ select PM_OPP
++ help
++ This adds a generic cpufreq driver for CPU0 frequency management.
++ It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
++ systems which share clock and voltage across all CPUs.
++
++ If in doubt, say N.
++
+ menu "x86 CPU frequency scaling drivers"
+ depends on X86
+ source "drivers/cpufreq/Kconfig.x86"
+diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
+index 7494565..f6f4485 100644
+--- a/drivers/cpufreq/Makefile
++++ b/drivers/cpufreq/Makefile
+@@ -12,6 +12,7 @@ obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE) += cpufreq_conservative.o
+ obj-$(CONFIG_CPU_FREQ_GOV_COMMON) += cpufreq_governor.o
+
+ obj-$(CONFIG_GENERIC_CPUFREQ_CPU0) += cpufreq-cpu0.o
++obj-$(CONFIG_GENERIC_CPUFREQ_KRAIT) += cpufreq-krait.o
+
+ ##################################################################################
+ # x86 drivers.
+diff --git a/drivers/cpufreq/cpufreq-krait.c b/drivers/cpufreq/cpufreq-krait.c
+new file mode 100644
+index 0000000..7b38b9c
+--- /dev/null
++++ b/drivers/cpufreq/cpufreq-krait.c
+@@ -0,0 +1,190 @@
++/*
++ * Copyright (C) 2012 Freescale Semiconductor, Inc.
++ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
++ *
++ * The OPP code in function krait_set_target() is reused from
++ * drivers/cpufreq/omap-cpufreq.c
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ */
++
++#include <linux/clk.h>
++#include <linux/cpu.h>
++#include <linux/cpu_cooling.h>
++#include <linux/cpufreq.h>
++#include <linux/cpumask.h>
++#include <linux/err.h>
++#include <linux/module.h>
++#include <linux/of.h>
++#include <linux/pm_opp.h>
++#include <linux/platform_device.h>
++#include <linux/slab.h>
++#include <linux/thermal.h>
++
++static unsigned int transition_latency;
++
++static struct device *cpu_dev;
++static DEFINE_PER_CPU(struct clk *, krait_cpu_clks);
++static struct cpufreq_frequency_table *freq_table;
++static struct thermal_cooling_device *cdev;
++
++static int krait_set_target(struct cpufreq_policy *policy, unsigned int index)
++{
++ unsigned long volt = 0, volt_old = 0;
++ unsigned int old_freq, new_freq;
++ long freq_Hz, freq_exact;
++ int ret;
++ struct clk *cpu_clk;
++
++ cpu_clk = per_cpu(krait_cpu_clks, policy->cpu);
++
++ freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
++ if (freq_Hz <= 0)
++ freq_Hz = freq_table[index].frequency * 1000;
++
++ freq_exact = freq_Hz;
++ new_freq = freq_Hz / 1000;
++ old_freq = clk_get_rate(cpu_clk) / 1000;
++
++ pr_debug("%u MHz, %ld mV --> %u MHz, %ld mV\n",
++ old_freq / 1000, volt_old ? volt_old / 1000 : -1,
++ new_freq / 1000, volt ? volt / 1000 : -1);
++
++ ret = clk_set_rate(cpu_clk, freq_exact);
++ if (ret)
++ pr_err("failed to set clock rate: %d\n", ret);
++
++ return ret;
++}
++
++static int krait_cpufreq_init(struct cpufreq_policy *policy)
++{
++ int ret;
++
++ policy->clk = per_cpu(krait_cpu_clks, policy->cpu);
++
++ ret = cpufreq_table_validate_and_show(policy, freq_table);
++ if (ret) {
++ pr_err("%s: invalid frequency table: %d\n", __func__, ret);
++ return ret;
++ }
++
++ policy->cpuinfo.transition_latency = transition_latency;
++
++ return 0;
++}
++
++static struct cpufreq_driver krait_cpufreq_driver = {
++ .flags = CPUFREQ_STICKY,
++ .verify = cpufreq_generic_frequency_table_verify,
++ .target_index = krait_set_target,
++ .get = cpufreq_generic_get,
++ .init = krait_cpufreq_init,
++ .name = "generic_krait",
++ .attr = cpufreq_generic_attr,
++};
++
++static int krait_cpufreq_probe(struct platform_device *pdev)
++{
++ struct device_node *np;
++ int ret;
++ unsigned int cpu;
++ struct device *dev;
++ struct clk *clk;
++
++ cpu_dev = get_cpu_device(0);
++ if (!cpu_dev) {
++ pr_err("failed to get krait device\n");
++ return -ENODEV;
++ }
++
++ np = of_node_get(cpu_dev->of_node);
++ if (!np) {
++ pr_err("failed to find krait node\n");
++ return -ENOENT;
++ }
++
++ for_each_possible_cpu(cpu) {
++ dev = get_cpu_device(cpu);
++ if (!dev) {
++ pr_err("failed to get krait device\n");
++ ret = -ENOENT;
++ goto out_put_node;
++ }
++ per_cpu(krait_cpu_clks, cpu) = clk = devm_clk_get(dev, NULL);
++ if (IS_ERR(clk)) {
++ ret = PTR_ERR(clk);
++ goto out_put_node;
++ }
++ }
++
++ ret = of_init_opp_table(cpu_dev);
++ if (ret) {
++ pr_err("failed to init OPP table: %d\n", ret);
++ goto out_put_node;
++ }
++
++ ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
++ if (ret) {
++ pr_err("failed to init cpufreq table: %d\n", ret);
++ goto out_put_node;
++ }
++
++ if (of_property_read_u32(np, "clock-latency", &transition_latency))
++ transition_latency = CPUFREQ_ETERNAL;
++
++ ret = cpufreq_register_driver(&krait_cpufreq_driver);
++ if (ret) {
++ pr_err("failed register driver: %d\n", ret);
++ goto out_free_table;
++ }
++ of_node_put(np);
++
++ /*
++ * For now, just loading the cooling device;
++ * thermal DT code takes care of matching them.
++ */
++ for_each_possible_cpu(cpu) {
++ dev = get_cpu_device(cpu);
++ np = of_node_get(dev->of_node);
++ if (of_find_property(np, "#cooling-cells", NULL)) {
++ cdev = of_cpufreq_cooling_register(np, cpumask_of(cpu));
++ if (IS_ERR(cdev))
++ pr_err("running cpufreq without cooling device: %ld\n",
++ PTR_ERR(cdev));
++ }
++ of_node_put(np);
++ }
++
++ return 0;
++
++out_free_table:
++ dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
++out_put_node:
++ of_node_put(np);
++ return ret;
++}
++
++static int krait_cpufreq_remove(struct platform_device *pdev)
++{
++ cpufreq_cooling_unregister(cdev);
++ cpufreq_unregister_driver(&krait_cpufreq_driver);
++ dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
++
++ return 0;
++}
++
++static struct platform_driver krait_cpufreq_platdrv = {
++ .driver = {
++ .name = "cpufreq-krait",
++ .owner = THIS_MODULE,
++ },
++ .probe = krait_cpufreq_probe,
++ .remove = krait_cpufreq_remove,
++};
++module_platform_driver(krait_cpufreq_platdrv);
++
++MODULE_DESCRIPTION("Krait CPUfreq driver");
++MODULE_LICENSE("GPL v2");
+--
+1.7.10.4
+
projects / openwrt / svn-archive / archive.git / blobdiff