--- /dev/null
+From a430fa942b3ff0e51f472e53110b7f6b16290295 Mon Sep 17 00:00:00 2001
+From: John Crispin <blogic@openwrt.org>
+Date: Wed, 30 Mar 2016 23:48:53 +0200
+Subject: [PATCH 63/91] cpufreq: mediatek: add driver
+
+Signed-off-by: John Crispin <john@phrozen.org>
+---
+ drivers/cpufreq/Kconfig.arm | 9 +
+ drivers/cpufreq/Makefile | 1 +
+ drivers/cpufreq/mt7623-cpufreq.c | 389 ++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 399 insertions(+)
+ create mode 100644 drivers/cpufreq/mt7623-cpufreq.c
+
+diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
+index b1f8a73..baf945e 100644
+--- a/drivers/cpufreq/Kconfig.arm
++++ b/drivers/cpufreq/Kconfig.arm
+@@ -81,6 +81,15 @@ config ARM_KIRKWOOD_CPUFREQ
+ This adds the CPUFreq driver for Marvell Kirkwood
+ SoCs.
+
++config ARM_MT7623_CPUFREQ
++ bool "Mediatek MT7623 CPUFreq support"
++ depends on ARCH_MEDIATEK && REGULATOR
++ depends on ARM || (ARM_CPU_TOPOLOGY && COMPILE_TEST)
++ depends on !CPU_THERMAL || THERMAL=y
++ select PM_OPP
++ help
++ This adds the CPUFreq driver support for Mediatek MT7623 SoC.
++
+ config ARM_MT8173_CPUFREQ
+ bool "Mediatek MT8173 CPUFreq support"
+ depends on ARCH_MEDIATEK && REGULATOR
+diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
+index c0af1a1..e198752 100644
+--- a/drivers/cpufreq/Makefile
++++ b/drivers/cpufreq/Makefile
+@@ -57,6 +57,7 @@ obj-$(CONFIG_ARM_HISI_ACPU_CPUFREQ) += hisi-acpu-cpufreq.o
+ obj-$(CONFIG_ARM_IMX6Q_CPUFREQ) += imx6q-cpufreq.o
+ obj-$(CONFIG_ARM_INTEGRATOR) += integrator-cpufreq.o
+ obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
++obj-$(CONFIG_ARM_MT7623_CPUFREQ) += mt7623-cpufreq.o
+ obj-$(CONFIG_ARM_MT8173_CPUFREQ) += mt8173-cpufreq.o
+ obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
+ obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o
+diff --git a/drivers/cpufreq/mt7623-cpufreq.c b/drivers/cpufreq/mt7623-cpufreq.c
+new file mode 100644
+index 0000000..8d154ce
+--- /dev/null
++++ b/drivers/cpufreq/mt7623-cpufreq.c
+@@ -0,0 +1,389 @@
++/*
++ * Copyright (c) 2015 Linaro Ltd.
++ * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
++ *
++ * 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.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
++ * GNU General Public License for more details.
++ */
++
++#include <linux/clk.h>
++#include <linux/cpu.h>
++#include <linux/cpu_cooling.h>
++#include <linux/cpufreq.h>
++#include <linux/cpumask.h>
++#include <linux/of.h>
++#include <linux/platform_device.h>
++#include <linux/pm_opp.h>
++#include <linux/regulator/consumer.h>
++#include <linux/slab.h>
++#include <linux/thermal.h>
++
++#define VOLT_TOL (10000)
++
++/*
++ * When scaling the clock frequency of a CPU clock domain, the clock source
++ * needs to be switched to another stable PLL clock temporarily until
++ * the original PLL becomes stable at target frequency.
++ */
++struct mtk_cpu_dvfs_info {
++ struct device *cpu_dev;
++ struct regulator *proc_reg;
++ struct clk *cpu_clk;
++ struct clk *inter_clk;
++ struct thermal_cooling_device *cdev;
++ int intermediate_voltage;
++};
++
++static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
++{
++ return regulator_set_voltage(info->proc_reg, vproc,
++ vproc + VOLT_TOL);
++}
++
++static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
++ unsigned int index)
++{
++ struct cpufreq_frequency_table *freq_table = policy->freq_table;
++ struct clk *cpu_clk = policy->clk;
++ struct clk *armpll = clk_get_parent(cpu_clk);
++ struct mtk_cpu_dvfs_info *info = policy->driver_data;
++ struct device *cpu_dev = info->cpu_dev;
++ struct dev_pm_opp *opp;
++ long freq_hz, old_freq_hz;
++ int vproc, old_vproc, inter_vproc, target_vproc, ret;
++
++ inter_vproc = info->intermediate_voltage;
++
++ old_freq_hz = clk_get_rate(cpu_clk);
++ old_vproc = regulator_get_voltage(info->proc_reg);
++
++ freq_hz = freq_table[index].frequency * 1000;
++
++ rcu_read_lock();
++ opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
++ if (IS_ERR(opp)) {
++ rcu_read_unlock();
++ pr_err("cpu%d: failed to find OPP for %ld\n",
++ policy->cpu, freq_hz);
++ return PTR_ERR(opp);
++ }
++ vproc = dev_pm_opp_get_voltage(opp);
++ rcu_read_unlock();
++
++ /*
++ * If the new voltage or the intermediate voltage is higher than the
++ * current voltage, scale up voltage first.
++ */
++ target_vproc = (inter_vproc > vproc) ? inter_vproc : vproc;
++ if (old_vproc < target_vproc) {
++ ret = mtk_cpufreq_set_voltage(info, target_vproc);
++ if (ret) {
++ pr_err("cpu%d: failed to scale up voltage!\n",
++ policy->cpu);
++ mtk_cpufreq_set_voltage(info, old_vproc);
++ return ret;
++ }
++ }
++
++ /* Reparent the CPU clock to intermediate clock. */
++ ret = clk_set_parent(cpu_clk, info->inter_clk);
++ if (ret) {
++ pr_err("cpu%d: failed to re-parent cpu clock!\n",
++ policy->cpu);
++ mtk_cpufreq_set_voltage(info, old_vproc);
++ WARN_ON(1);
++ return ret;
++ }
++
++ /* Set the original PLL to target rate. */
++ ret = clk_set_rate(armpll, freq_hz);
++ if (ret) {
++ pr_err("cpu%d: failed to scale cpu clock rate!\n",
++ policy->cpu);
++ clk_set_parent(cpu_clk, armpll);
++ mtk_cpufreq_set_voltage(info, old_vproc);
++ return ret;
++ }
++
++ /* Set parent of CPU clock back to the original PLL. */
++ ret = clk_set_parent(cpu_clk, armpll);
++ if (ret) {
++ pr_err("cpu%d: failed to re-parent cpu clock!\n",
++ policy->cpu);
++ mtk_cpufreq_set_voltage(info, inter_vproc);
++ WARN_ON(1);
++ return ret;
++ }
++
++ /*
++ * If the new voltage is lower than the intermediate voltage or the
++ * original voltage, scale down to the new voltage.
++ */
++ if (vproc < inter_vproc || vproc < old_vproc) {
++ ret = mtk_cpufreq_set_voltage(info, vproc);
++ if (ret) {
++ pr_err("cpu%d: failed to scale down voltage!\n",
++ policy->cpu);
++ clk_set_parent(cpu_clk, info->inter_clk);
++ clk_set_rate(armpll, old_freq_hz);
++ clk_set_parent(cpu_clk, armpll);
++ return ret;
++ }
++ }
++
++ return 0;
++}
++
++static void mtk_cpufreq_ready(struct cpufreq_policy *policy)
++{
++ struct mtk_cpu_dvfs_info *info = policy->driver_data;
++ struct device_node *np = of_node_get(info->cpu_dev->of_node);
++
++ if (WARN_ON(!np))
++ return;
++
++ if (of_find_property(np, "#cooling-cells", NULL)) {
++ info->cdev = of_cpufreq_cooling_register(np,
++ policy->related_cpus);
++
++ if (IS_ERR(info->cdev)) {
++ dev_err(info->cpu_dev,
++ "running cpufreq without cooling device: %ld\n",
++ PTR_ERR(info->cdev));
++
++ info->cdev = NULL;
++ }
++ }
++
++ of_node_put(np);
++}
++
++static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu)
++{
++ struct device *cpu_dev;
++ struct regulator *proc_reg = ERR_PTR(-ENODEV);
++ struct clk *cpu_clk = ERR_PTR(-ENODEV);
++ struct clk *inter_clk = ERR_PTR(-ENODEV);
++ struct dev_pm_opp *opp;
++ unsigned long rate;
++ int ret;
++
++ cpu_dev = get_cpu_device(cpu);
++ if (!cpu_dev) {
++ pr_err("failed to get cpu%d device\n", cpu);
++ return -ENODEV;
++ }
++
++ cpu_clk = clk_get(cpu_dev, "cpu");
++ if (IS_ERR(cpu_clk)) {
++ if (PTR_ERR(cpu_clk) == -EPROBE_DEFER)
++ pr_warn("cpu clk for cpu%d not ready, retry.\n", cpu);
++ else
++ pr_err("failed to get cpu clk for cpu%d\n", cpu);
++
++ ret = PTR_ERR(cpu_clk);
++ return ret;
++ }
++
++ inter_clk = clk_get(cpu_dev, "intermediate");
++ if (IS_ERR(inter_clk)) {
++ if (PTR_ERR(inter_clk) == -EPROBE_DEFER)
++ pr_warn("intermediate clk for cpu%d not ready, retry.\n",
++ cpu);
++ else
++ pr_err("failed to get intermediate clk for cpu%d\n",
++ cpu);
++
++ ret = PTR_ERR(inter_clk);
++ goto out_free_resources;
++ }
++
++ proc_reg = regulator_get_exclusive(cpu_dev, "proc");
++ if (IS_ERR(proc_reg)) {
++ if (PTR_ERR(proc_reg) == -EPROBE_DEFER)
++ pr_warn("proc regulator for cpu%d not ready, retry.\n",
++ cpu);
++ else
++ pr_err("failed to get proc regulator for cpu%d\n",
++ cpu);
++
++ ret = PTR_ERR(proc_reg);
++ goto out_free_resources;
++ }
++
++ ret = dev_pm_opp_of_add_table(cpu_dev);
++ if (ret) {
++ pr_warn("no OPP table for cpu%d\n", cpu);
++ goto out_free_resources;
++ }
++
++ /* Search a safe voltage for intermediate frequency. */
++ rate = clk_get_rate(inter_clk);
++ rcu_read_lock();
++ opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
++ if (IS_ERR(opp)) {
++ rcu_read_unlock();
++ pr_err("failed to get intermediate opp for cpu%d\n", cpu);
++ ret = PTR_ERR(opp);
++ goto out_free_opp_table;
++ }
++ info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
++ rcu_read_unlock();
++
++ info->cpu_dev = cpu_dev;
++ info->proc_reg = proc_reg;
++ info->cpu_clk = cpu_clk;
++ info->inter_clk = inter_clk;
++
++ return 0;
++
++out_free_opp_table:
++ dev_pm_opp_of_remove_table(cpu_dev);
++
++out_free_resources:
++ if (!IS_ERR(proc_reg))
++ regulator_put(proc_reg);
++ if (!IS_ERR(cpu_clk))
++ clk_put(cpu_clk);
++ if (!IS_ERR(inter_clk))
++ clk_put(inter_clk);
++
++ return ret;
++}
++
++static void mtk_cpu_dvfs_info_release(struct mtk_cpu_dvfs_info *info)
++{
++ if (!IS_ERR(info->proc_reg))
++ regulator_put(info->proc_reg);
++ if (!IS_ERR(info->cpu_clk))
++ clk_put(info->cpu_clk);
++ if (!IS_ERR(info->inter_clk))
++ clk_put(info->inter_clk);
++
++ dev_pm_opp_of_remove_table(info->cpu_dev);
++}
++
++static int mtk_cpufreq_init(struct cpufreq_policy *policy)
++{
++ struct mtk_cpu_dvfs_info *info;
++ struct cpufreq_frequency_table *freq_table;
++ int ret;
++
++ info = kzalloc(sizeof(*info), GFP_KERNEL);
++ if (!info)
++ return -ENOMEM;
++
++ ret = mtk_cpu_dvfs_info_init(info, policy->cpu);
++ if (ret) {
++ pr_err("%s failed to initialize dvfs info for cpu%d\n",
++ __func__, policy->cpu);
++ goto out_free_dvfs_info;
++ }
++
++ ret = dev_pm_opp_init_cpufreq_table(info->cpu_dev, &freq_table);
++ if (ret) {
++ pr_err("failed to init cpufreq table for cpu%d: %d\n",
++ policy->cpu, ret);
++ goto out_release_dvfs_info;
++ }
++
++ ret = cpufreq_table_validate_and_show(policy, freq_table);
++ if (ret) {
++ pr_err("%s: invalid frequency table: %d\n", __func__, ret);
++ goto out_free_cpufreq_table;
++ }
++
++ /* CPUs in the same cluster share a clock and power domain. */
++ cpumask_setall(policy->cpus);
++ policy->driver_data = info;
++ policy->clk = info->cpu_clk;
++
++ return 0;
++
++out_free_cpufreq_table:
++ dev_pm_opp_free_cpufreq_table(info->cpu_dev, &freq_table);
++
++out_release_dvfs_info:
++ mtk_cpu_dvfs_info_release(info);
++
++out_free_dvfs_info:
++ kfree(info);
++
++ return ret;
++}
++
++static int mtk_cpufreq_exit(struct cpufreq_policy *policy)
++{
++ struct mtk_cpu_dvfs_info *info = policy->driver_data;
++
++ cpufreq_cooling_unregister(info->cdev);
++ dev_pm_opp_free_cpufreq_table(info->cpu_dev, &policy->freq_table);
++ mtk_cpu_dvfs_info_release(info);
++ kfree(info);
++
++ return 0;
++}
++
++static struct cpufreq_driver mt7623_cpufreq_driver = {
++ .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
++ .verify = cpufreq_generic_frequency_table_verify,
++ .target_index = mtk_cpufreq_set_target,
++ .get = cpufreq_generic_get,
++ .init = mtk_cpufreq_init,
++ .exit = mtk_cpufreq_exit,
++ .ready = mtk_cpufreq_ready,
++ .name = "mtk-cpufreq",
++ .attr = cpufreq_generic_attr,
++};
++
++static int mt7623_cpufreq_probe(struct platform_device *pdev)
++{
++ int ret;
++
++ ret = cpufreq_register_driver(&mt7623_cpufreq_driver);
++ if (ret)
++ pr_err("failed to register mtk cpufreq driver\n");
++
++ return ret;
++}
++
++static struct platform_driver mt7623_cpufreq_platdrv = {
++ .driver = {
++ .name = "mt7623-cpufreq",
++ },
++ .probe = mt7623_cpufreq_probe,
++};
++
++static int mt7623_cpufreq_driver_init(void)
++{
++ struct platform_device *pdev;
++ int err;
++
++ if (!of_machine_is_compatible("mediatek,mt7623"))
++ return -ENODEV;
++
++ err = platform_driver_register(&mt7623_cpufreq_platdrv);
++ if (err)
++ return err;
++
++ /*
++ * Since there's no place to hold device registration code and no
++ * device tree based way to match cpufreq driver yet, both the driver
++ * and the device registration codes are put here to handle defer
++ * probing.
++ */
++ pdev = platform_device_register_simple("mt7623-cpufreq", -1, NULL, 0);
++ if (IS_ERR(pdev)) {
++ pr_err("failed to register mtk-cpufreq platform device\n");
++ return PTR_ERR(pdev);
++ }
++
++ return 0;
++}
++device_initcall(mt7623_cpufreq_driver_init);
+--
+1.7.10.4
+
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