ipq806x: add & enable cpufreq support

This change set enables frequency scaling on ipq806x, which speeds-up
the CPU and allows it to achieve its max frequency.

These patches are cherry-picked & backported from the following location:
*130-132: linux-next
*133-143: LKML - https://lkml.org/lkml/2015/3/21/15
*144: derived from other qcom similar dts
*145: derived from https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.14/drivers/cpufreq/cpufreq-krait.c

Signed-off-by: Mathieu Olivari <mathieu@codeaurora.org>

SVN-Revision: 45730

1 files changed, 461 insertions, 0 deletions

diff --git a/target/linux/ipq806x/patches-4.0/145-cpufreq-Add-a-cpufreq-krait-based-on-cpufre.patch b/target/linux/ipq806x/patches-4.0/145-cpufreq-Add-a-cpufreq-krait-based-on-cpufre.patch
new file mode 100644
index 0000000000..521adc5c1e
--- /dev/null
+++ b/target/linux/ipq806x/patches-4.0/145-cpufreq-Add-a-cpufreq-krait-based-on-cpufre.patch
@@ -0,0 +1,461 @@
+From dd77db4143290689d3a5e1ec61627233d0711b66 Mon Sep 17 00:00:00 2001
+From: Stephen Boyd <sboyd@codeaurora.org>
+Date: Fri, 30 May 2014 16:36:11 -0700
+Subject: [PATCH] FROMLIST: 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
+
+--- a/drivers/cpufreq/Kconfig
++++ b/drivers/cpufreq/Kconfig
+@@ -198,6 +198,19 @@ config CPUFREQ_DT
+ 
+ 	  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.
++
+ if X86
+ source "drivers/cpufreq/Kconfig.x86"
+ endif
+--- a/drivers/cpufreq/Makefile
++++ b/drivers/cpufreq/Makefile
+@@ -14,6 +14,7 @@ obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE)
+ obj-$(CONFIG_CPU_FREQ_GOV_COMMON)		+= cpufreq_governor.o
+ 
+ obj-$(CONFIG_CPUFREQ_DT)		+= cpufreq-dt.o
++obj-$(CONFIG_GENERIC_CPUFREQ_KRAIT)	+= cpufreq-krait.o
+ 
+ ##################################################################################
+ # x86 drivers.
+--- /dev/null
++++ b/drivers/cpufreq/cpufreq-krait.c
+@@ -0,0 +1,390 @@
++/*
++ * 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/regulator/consumer.h>
++#include <linux/slab.h>
++#include <linux/thermal.h>
++
++static unsigned int transition_latency;
++static unsigned int voltage_tolerance; /* in percentage */
++
++static struct device *cpu_dev;
++static DEFINE_PER_CPU(struct clk *, krait_cpu_clks);
++static DEFINE_PER_CPU(struct regulator *, krait_supply_core);
++static struct cpufreq_frequency_table *freq_table;
++static struct thermal_cooling_device *cdev;
++
++struct cache_points {
++	unsigned long cache_freq;
++	unsigned int cache_volt;
++	unsigned long cpu_freq;
++};
++
++static struct regulator *krait_l2_reg;
++static struct clk *krait_l2_clk;
++static struct cache_points *krait_l2_points;
++static int nr_krait_l2_points;
++
++static int krait_parse_cache_points(struct device *dev,
++		struct device_node *of_node)
++{
++	const struct property *prop;
++	const __be32 *val;
++	int nr, i;
++
++	prop = of_find_property(of_node, "cache-points-kHz", NULL);
++	if (!prop)
++		return -ENODEV;
++	if (!prop->value)
++		return -ENODATA;
++
++	/*
++	 * Each OPP is a set of tuples consisting of frequency and
++	 * cpu-frequency like <freq-kHz volt-uV freq-kHz>.
++	 */
++	nr = prop->length / sizeof(u32);
++	if (nr % 3) {
++		dev_err(dev, "%s: Invalid cache points\n", __func__);
++		return -EINVAL;
++	}
++	nr /= 3;
++
++	krait_l2_points = devm_kcalloc(dev, nr, sizeof(*krait_l2_points),
++				       GFP_KERNEL);
++	if (!krait_l2_points)
++		return -ENOMEM;
++	nr_krait_l2_points = nr;
++
++	for (i = 0, val = prop->value; i < nr; i++) {
++		unsigned long cache_freq = be32_to_cpup(val++) * 1000;
++		unsigned int cache_volt = be32_to_cpup(val++);
++		unsigned long cpu_freq = be32_to_cpup(val++) * 1000;
++
++		krait_l2_points[i].cache_freq = cache_freq;
++		krait_l2_points[i].cache_volt = cache_volt;
++		krait_l2_points[i].cpu_freq = cpu_freq;
++	}
++
++	return 0;
++}
++
++static int krait_set_target(struct cpufreq_policy *policy, unsigned int index)
++{
++	struct dev_pm_opp *opp;
++	unsigned long volt = 0, volt_old = 0, tol = 0;
++	unsigned long freq, max_cpu_freq = 0;
++	unsigned int old_freq, new_freq;
++	long freq_Hz, freq_exact;
++	int ret, i;
++	struct clk *cpu_clk;
++	struct regulator *core;
++	unsigned int cpu;
++
++	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;
++
++	core = per_cpu(krait_supply_core, policy->cpu);
++
++	rcu_read_lock();
++	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
++	if (IS_ERR(opp)) {
++		rcu_read_unlock();
++		pr_err("failed to find OPP for %ld\n", freq_Hz);
++		return PTR_ERR(opp);
++	}
++	volt = dev_pm_opp_get_voltage(opp);
++	rcu_read_unlock();
++	tol = volt * voltage_tolerance / 100;
++	volt_old = regulator_get_voltage(core);
++
++	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);
++
++	/* scaling up?  scale voltage before frequency */
++	if (new_freq > old_freq) {
++		ret = regulator_set_voltage_tol(core, volt, tol);
++		if (ret) {
++			pr_err("failed to scale voltage up: %d\n", ret);
++			return ret;
++		}
++	}
++
++	ret = clk_set_rate(cpu_clk, freq_exact);
++	if (ret) {
++		pr_err("failed to set clock rate: %d\n", ret);
++		return ret;
++	}
++
++	/* scaling down?  scale voltage after frequency */
++	if (new_freq < old_freq) {
++		ret = regulator_set_voltage_tol(core, volt, tol);
++		if (ret) {
++			pr_err("failed to scale voltage down: %d\n", ret);
++			clk_set_rate(cpu_clk, old_freq * 1000);
++		}
++	}
++
++	for_each_possible_cpu(cpu) {
++		freq = clk_get_rate(per_cpu(krait_cpu_clks, cpu));
++		max_cpu_freq = max(max_cpu_freq, freq);
++	}
++
++	for (i = 0; i < nr_krait_l2_points; i++) {
++		if (max_cpu_freq >= krait_l2_points[i].cpu_freq) {
++			if (krait_l2_reg) {
++				ret = regulator_set_voltage_tol(krait_l2_reg,
++						krait_l2_points[i].cache_volt,
++						tol);
++				if (ret) {
++					pr_err("failed to scale l2 voltage: %d\n",
++						ret);
++				}
++			}
++			ret = clk_set_rate(krait_l2_clk,
++					krait_l2_points[i].cache_freq);
++			if (ret)
++				pr_err("failed to scale l2 clk: %d\n", ret);
++			break;
++		}
++
++	}
++
++	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, *cache;
++	int ret, i;
++	unsigned int cpu;
++	struct device *dev;
++	struct clk *clk;
++	struct regulator *core;
++	unsigned long freq_Hz, freq, max_cpu_freq;
++	struct dev_pm_opp *opp;
++	unsigned long volt, tol;
++
++	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;
++	}
++
++	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;
++	}
++
++	of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance);
++
++	if (of_property_read_u32(np, "clock-latency", &transition_latency))
++		transition_latency = CPUFREQ_ETERNAL;
++
++	cache = of_find_next_cache_node(np);
++	if (cache) {
++		struct device_node *vdd;
++
++		vdd = of_parse_phandle(cache, "vdd_dig-supply", 0);
++		if (vdd) {
++			krait_l2_reg = regulator_get(NULL, vdd->name);
++			if (IS_ERR(krait_l2_reg)) {
++				pr_warn("failed to get l2 vdd_dig supply\n");
++				krait_l2_reg = NULL;
++			}
++			of_node_put(vdd);
++		}
++
++		krait_l2_clk = of_clk_get(cache, 0);
++		if (!IS_ERR(krait_l2_clk)) {
++			ret = krait_parse_cache_points(&pdev->dev, cache);
++			if (ret)
++				clk_put(krait_l2_clk);
++		}
++		if (IS_ERR(krait_l2_clk) || ret)
++			krait_l2_clk = NULL;
++	}
++
++	for_each_possible_cpu(cpu) {
++		dev = get_cpu_device(cpu);
++		if (!dev) {
++			pr_err("failed to get krait device\n");
++			ret = -ENOENT;
++			goto out_free_table;
++		}
++		per_cpu(krait_cpu_clks, cpu) = clk = devm_clk_get(dev, NULL);
++		if (IS_ERR(clk)) {
++			ret = PTR_ERR(clk);
++			goto out_free_table;
++		}
++		core = devm_regulator_get(dev, "core");
++		if (IS_ERR(core)) {
++			pr_debug("failed to get core regulator\n");
++			ret = PTR_ERR(core);
++			goto out_free_table;
++		}
++		per_cpu(krait_supply_core, cpu) = core;
++
++		freq_Hz = clk_get_rate(clk);
++
++		rcu_read_lock();
++		opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
++		if (IS_ERR(opp)) {
++			rcu_read_unlock();
++			pr_err("failed to find OPP for %ld\n", freq_Hz);
++			ret = PTR_ERR(opp);
++			goto out_free_table;
++		}
++		volt = dev_pm_opp_get_voltage(opp);
++		rcu_read_unlock();
++
++		tol = volt * voltage_tolerance / 100;
++		ret = regulator_set_voltage_tol(core, volt, tol);
++		if (ret) {
++			pr_err("failed to scale voltage up: %d\n", ret);
++			goto out_free_table;
++		}
++		ret = regulator_enable(core);
++		if (ret) {
++			pr_err("failed to enable regulator: %d\n", ret);
++			goto out_free_table;
++		}
++		max_cpu_freq = max(max_cpu_freq, freq);
++	}
++
++	for (i = 0; i < nr_krait_l2_points; i++) {
++		if (max_cpu_freq >= krait_l2_points[i].cpu_freq) {
++			if (krait_l2_reg) {
++				ret = regulator_set_voltage_tol(krait_l2_reg,
++						krait_l2_points[i].cache_volt,
++						tol);
++				if (ret)
++					pr_err("failed to scale l2 voltage: %d\n",
++							ret);
++				ret = regulator_enable(krait_l2_reg);
++				if (ret)
++					pr_err("failed to enable l2 voltage: %d\n",
++							ret);
++			}
++			break;
++		}
++
++	}
++
++	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:
++	regulator_put(krait_l2_reg);
++	clk_put(krait_l2_clk);
++	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);
++	clk_put(krait_l2_clk);
++	regulator_put(krait_l2_reg);
++
++	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");
+--- a/drivers/cpufreq/qcom-cpufreq.c
++++ b/drivers/cpufreq/qcom-cpufreq.c
+@@ -168,11 +168,8 @@ static int __init qcom_cpufreq_populate_
+ 
+ static int __init qcom_cpufreq_driver_init(void)
+ {
+-	struct cpufreq_dt_platform_data pdata = { .independent_clocks = true };
+ 	struct platform_device_info devinfo = {
+-		.name = "cpufreq-dt",
+-		.data = &pdata,
+-		.size_data = sizeof(pdata),
++		.name = "cpufreq-krait",
+ 	};
+ 	struct device *cpu_dev;
+ 	struct device_node *np;