mediatek: add support for the new MT7623 Arm SoC

the support is still WIP. next steps are to make the pmic and ethernet work.
this is the first commit to make sure nothing gets lost.

Signed-off-by: John Crispin <blogic@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@47354 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 604 insertions, 0 deletions

diff --git a/target/linux/mediatek/patches/0033-cpufreq-mediatek-Add-MT8173-cpufreq-driver.patch b/target/linux/mediatek/patches/0033-cpufreq-mediatek-Add-MT8173-cpufreq-driver.patch
new file mode 100644
index 0000000000..81ae4f8275
--- /dev/null
+++ b/target/linux/mediatek/patches/0033-cpufreq-mediatek-Add-MT8173-cpufreq-driver.patch
@@ -0,0 +1,604 @@
+From 2028cb37c941014f6a817d27a867ee1d37ccf2b6 Mon Sep 17 00:00:00 2001
+From: "pi-cheng.chen" <pi-cheng.chen@linaro.org>
+Date: Mon, 8 Jun 2015 20:29:21 +0800
+Subject: [PATCH 33/76] cpufreq: mediatek: Add MT8173 cpufreq driver
+
+This patch implements MT8173 cpufreq driver.
+
+Signed-off-by: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
+---
+ drivers/cpufreq/Kconfig.arm      |    7 +
+ drivers/cpufreq/Makefile         |    1 +
+ drivers/cpufreq/mt8173-cpufreq.c |  550 ++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 558 insertions(+)
+ create mode 100644 drivers/cpufreq/mt8173-cpufreq.c
+
+diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
+index 4f3dbc8..350752b 100644
+--- a/drivers/cpufreq/Kconfig.arm
++++ b/drivers/cpufreq/Kconfig.arm
+@@ -141,6 +141,13 @@ config ARM_KIRKWOOD_CPUFREQ
+ 	  This adds the CPUFreq driver for Marvell Kirkwood
+ 	  SoCs.
+ 
++config ARM_MT8173_CPUFREQ
++	bool "Mediatek MT8173 CPUFreq support"
++	depends on ARCH_MEDIATEK && REGULATOR
++	select PM_OPP
++	help
++	  This adds the CPUFreq driver support for Mediatek MT8173 SoC.
++
+ config ARM_OMAP2PLUS_CPUFREQ
+ 	bool "TI OMAP2+"
+ 	depends on ARCH_OMAP2PLUS
+diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
+index cdce92a..97f9a9b 100644
+--- a/drivers/cpufreq/Makefile
++++ b/drivers/cpufreq/Makefile
+@@ -63,6 +63,7 @@ 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-$(CONFIG_ARM_MT8173_CPUFREQ)	+= mt8173-cpufreq.o
+ obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ)	+= omap-cpufreq.o
+ obj-$(CONFIG_ARM_PXA2xx_CPUFREQ)	+= pxa2xx-cpufreq.o
+ obj-$(CONFIG_PXA3xx)			+= pxa3xx-cpufreq.o
+diff --git a/drivers/cpufreq/mt8173-cpufreq.c b/drivers/cpufreq/mt8173-cpufreq.c
+new file mode 100644
+index 0000000..d539e7b
+--- /dev/null
++++ b/drivers/cpufreq/mt8173-cpufreq.c
+@@ -0,0 +1,550 @@
++/*
++ * 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/cpufreq.h>
++#include <linux/cpumask.h>
++#include <linux/module.h>
++#include <linux/of.h>
++#include <linux/platform_device.h>
++#include <linux/pm_opp.h>
++#include <linux/regulator/consumer.h>
++#include <linux/slab.h>
++
++#define MIN_VOLT_SHIFT		(100000)
++#define MAX_VOLT_SHIFT		(200000)
++#define MAX_VOLT_LIMIT		(1150000)
++#define VOLT_TOL		(10000)
++
++/*
++ * The struct mtk_cpu_dvfs_info holds necessary information for doing CPU DVFS
++ * on each CPU power/clock domain of Mediatek SoCs. Each CPU cluster in
++ * Mediatek SoCs has two voltage inputs, Vproc and Vsram. In some cases the two
++ * voltage inputs need to be controlled under a hardware limitation:
++ * 100mV < Vsram - Vproc < 200mV
++ *
++ * 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 list_head node;
++	cpumask_var_t cpus;
++	struct cpufreq_frequency_table *freq_table;
++	struct device *cpu_dev;
++	struct regulator *proc_reg;
++	struct regulator *sram_reg;
++	struct clk *cpu_clk;
++	struct clk *inter_clk;
++	int intermediate_voltage;
++	bool need_voltage_trace;
++};
++
++static LIST_HEAD(cpu_dvfs_info_list);
++
++static inline struct mtk_cpu_dvfs_info *to_mtk_cpu_dvfs_info(
++			struct list_head *list)
++{
++	return list_entry(list, struct mtk_cpu_dvfs_info, node);
++}
++
++static inline void mtk_cpu_dvfs_info_add(struct mtk_cpu_dvfs_info *info)
++{
++	list_add(&info->node, &cpu_dvfs_info_list);
++}
++
++static struct mtk_cpu_dvfs_info *mtk_cpu_dvfs_info_get(int cpu)
++{
++	struct mtk_cpu_dvfs_info *info;
++	struct list_head *list;
++
++	list_for_each(list, &cpu_dvfs_info_list) {
++		info = to_mtk_cpu_dvfs_info(list);
++
++		if (cpumask_test_cpu(cpu, info->cpus))
++			return info;
++	}
++
++	return NULL;
++}
++
++static void mtk_cpu_dvfs_info_release(void)
++{
++	struct list_head *list, *tmp;
++	struct mtk_cpu_dvfs_info *info;
++
++	list_for_each_safe(list, tmp, &cpu_dvfs_info_list) {
++		info = to_mtk_cpu_dvfs_info(list);
++
++		dev_pm_opp_free_cpufreq_table(info->cpu_dev,
++					      &info->freq_table);
++
++		if (!IS_ERR(info->proc_reg))
++			regulator_put(info->proc_reg);
++		if (!IS_ERR(info->sram_reg))
++			regulator_put(info->sram_reg);
++		if (!IS_ERR(info->cpu_clk))
++			clk_put(info->cpu_clk);
++		if (!IS_ERR(info->inter_clk))
++			clk_put(info->inter_clk);
++
++		of_free_opp_table(info->cpu_dev);
++
++		list_del(list);
++		kfree(info);
++	}
++}
++
++#define MIN(a, b) ((a) < (b) ? (a) : (b))
++#define MAX(a, b) ((a) > (b) ? (a) : (b))
++
++static int mtk_cpufreq_voltage_trace(struct mtk_cpu_dvfs_info *info,
++				     int new_vproc)
++{
++	struct regulator *proc_reg = info->proc_reg;
++	struct regulator *sram_reg = info->sram_reg;
++	int old_vproc, old_vsram, new_vsram, vsram, vproc, ret;
++
++	old_vproc = regulator_get_voltage(proc_reg);
++	old_vsram = regulator_get_voltage(sram_reg);
++	/* Vsram should not exceed the maximum allowed voltage of SoC. */
++	new_vsram = min(new_vproc + MIN_VOLT_SHIFT, MAX_VOLT_LIMIT);
++
++	if (old_vproc < new_vproc) {
++		/*
++		 * When scaling up voltages, Vsram and Vproc scale up step
++		 * by step. At each step, set Vsram to (Vproc + 200mV) first,
++		 * then set Vproc to (Vsram - 100mV).
++		 * Keep doing it until Vsram and Vproc hit target voltages.
++		 */
++		do {
++			old_vsram = regulator_get_voltage(sram_reg);
++			old_vproc = regulator_get_voltage(proc_reg);
++
++			vsram = MIN(new_vsram, old_vproc + MAX_VOLT_SHIFT);
++
++			if (vsram + VOLT_TOL >= MAX_VOLT_LIMIT) {
++				vsram = MAX_VOLT_LIMIT;
++
++				/*
++				 * If the target Vsram hits the maximum voltage,
++				 * try to set the exact voltage value first.
++				 */
++				ret = regulator_set_voltage(sram_reg, vsram,
++							    vsram);
++				if (ret)
++					ret = regulator_set_voltage(sram_reg,
++							vsram - VOLT_TOL,
++							vsram);
++
++				vproc = new_vproc;
++			} else {
++				ret = regulator_set_voltage(sram_reg, vsram,
++							    vsram + VOLT_TOL);
++
++				vproc = vsram - MIN_VOLT_SHIFT;
++			}
++			if (ret)
++				return ret;
++
++			ret = regulator_set_voltage(proc_reg, vproc,
++						    vproc + VOLT_TOL);
++			if (ret) {
++				regulator_set_voltage(sram_reg, old_vsram,
++						      old_vsram);
++				return ret;
++			}
++		} while (vproc < new_vproc || vsram < new_vsram);
++	} else if (old_vproc > new_vproc) {
++		/*
++		 * When scaling down voltages, Vsram and Vproc scale down step
++		 * by step. At each step, set Vproc to (Vsram - 200mV) first,
++		 * then set Vproc to (Vproc + 100mV).
++		 * Keep doing it until Vsram and Vproc hit target voltages.
++		 */
++		do {
++			old_vproc = regulator_get_voltage(proc_reg);
++			old_vsram = regulator_get_voltage(sram_reg);
++
++			vproc = MAX(new_vproc, old_vsram - MAX_VOLT_SHIFT);
++			ret = regulator_set_voltage(proc_reg, vproc,
++						    vproc + VOLT_TOL);
++			if (ret)
++				return ret;
++
++			if (vproc == new_vproc)
++				vsram = new_vsram;
++			else
++				vsram = MAX(new_vsram, vproc + MIN_VOLT_SHIFT);
++
++			if (vsram + VOLT_TOL >= MAX_VOLT_LIMIT) {
++				vsram = MAX_VOLT_LIMIT;
++
++				/*
++				 * If the target Vsram hits the maximum voltage,
++				 * try to set the exact voltage value first.
++				 */
++				ret = regulator_set_voltage(sram_reg, vsram,
++							    vsram);
++				if (ret)
++					ret = regulator_set_voltage(sram_reg,
++							vsram - VOLT_TOL,
++							vsram);
++			} else {
++				ret = regulator_set_voltage(sram_reg, vsram,
++							    vsram + VOLT_TOL);
++			}
++
++			if (ret) {
++				regulator_set_voltage(proc_reg, old_vproc,
++						      old_vproc);
++				return ret;
++			}
++		} while (vproc > new_vproc + VOLT_TOL ||
++			 vsram > new_vsram + VOLT_TOL);
++	}
++
++	return 0;
++}
++
++static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
++{
++	if (info->need_voltage_trace)
++		return mtk_cpufreq_voltage_trace(info, vproc);
++	else
++		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 int mtk_cpufreq_init(struct cpufreq_policy *policy)
++{
++	struct mtk_cpu_dvfs_info *info;
++	int ret;
++
++	info = mtk_cpu_dvfs_info_get(policy->cpu);
++	if (!info) {
++		pr_err("%s: mtk cpu dvfs info for cpu%d is not initialized\n",
++		       __func__, policy->cpu);
++		return -ENODEV;
++	}
++
++	ret = cpufreq_table_validate_and_show(policy, info->freq_table);
++	if (ret) {
++		pr_err("%s: invalid frequency table: %d\n", __func__, ret);
++		return ret;
++	}
++
++	cpumask_copy(policy->cpus, info->cpus);
++	policy->driver_data = info;
++	policy->clk = info->cpu_clk;
++
++	return 0;
++}
++
++static struct cpufreq_driver mt8173_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,
++	.name = "mtk-cpufreq",
++	.attr = cpufreq_generic_attr,
++};
++
++static int mtk_cpu_dvfs_info_init(int cpu)
++{
++	struct device *cpu_dev;
++	struct regulator *proc_reg = ERR_PTR(-ENODEV);
++	struct regulator *sram_reg = ERR_PTR(-ENODEV);
++	struct clk *cpu_clk = ERR_PTR(-ENODEV);
++	struct clk *inter_clk = ERR_PTR(-ENODEV);
++	struct mtk_cpu_dvfs_info *info;
++	struct cpufreq_frequency_table *freq_table;
++	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;
++	}
++
++	ret = of_init_opp_table(cpu_dev);
++	if (ret) {
++		pr_warn("no OPP table for cpu%d\n", cpu);
++		return ret;
++	}
++
++	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);
++		goto out_free_opp_table;
++	}
++
++	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(cpu_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;
++	}
++
++	/* Both presence and absence of sram regulator are valid cases. */
++	sram_reg = regulator_get_exclusive(cpu_dev, "sram");
++
++	info = kzalloc(sizeof(*info), GFP_KERNEL);
++	if (!info) {
++		ret = -ENOMEM;
++		goto out_free_resources;
++	}
++
++	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
++	if (ret) {
++		pr_err("failed to init cpufreq table for cpu%d: %d\n",
++		       cpu, ret);
++		goto out_free_mtk_cpu_dvfs_info;
++	}
++
++	if (!alloc_cpumask_var(&info->cpus, GFP_KERNEL))
++		goto out_free_cpufreq_table;
++
++	/* 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)) {
++		pr_err("failed to get intermediate opp for cpu%d\n", cpu);
++		ret = PTR_ERR(opp);
++		goto out_free_cpumask;
++	}
++	info->intermediate_voltage = dev_pm_opp_get_voltage(opp);
++	rcu_read_unlock();
++
++	/* CPUs in the same cluster share a clock and power domain. */
++	cpumask_copy(info->cpus, &cpu_topology[cpu].core_sibling);
++
++	info->cpu_dev = cpu_dev;
++	info->proc_reg = proc_reg;
++	info->sram_reg = IS_ERR(sram_reg) ? NULL : sram_reg;
++	info->cpu_clk = cpu_clk;
++	info->inter_clk = inter_clk;
++	info->freq_table = freq_table;
++
++	/*
++	 * If SRAM regulator is present, software "voltage trace" is needed
++	 * for this CPU power domain.
++	 */
++	info->need_voltage_trace = !IS_ERR(sram_reg);
++
++	mtk_cpu_dvfs_info_add(info);
++
++	return 0;
++
++out_free_cpumask:
++	free_cpumask_var(info->cpus);
++
++out_free_cpufreq_table:
++	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
++
++out_free_mtk_cpu_dvfs_info:
++	kfree(info);
++
++out_free_resources:
++	if (!IS_ERR(proc_reg))
++		regulator_put(proc_reg);
++	if (!IS_ERR(sram_reg))
++		regulator_put(sram_reg);
++	if (!IS_ERR(cpu_clk))
++		clk_put(cpu_clk);
++	if (!IS_ERR(inter_clk))
++		clk_put(inter_clk);
++
++out_free_opp_table:
++	of_free_opp_table(cpu_dev);
++
++	return ret;
++}
++
++static int mt8173_cpufreq_probe(struct platform_device *pdev)
++{
++	int cpu, ret;
++
++	for_each_possible_cpu(cpu) {
++		/*
++		 * If the struct mtk_cpu_dvfs_info for the cpu power domain
++		 * is already initialized, skip this CPU.
++		 */
++		if (!mtk_cpu_dvfs_info_get(cpu)) {
++			ret = mtk_cpu_dvfs_info_init(cpu);
++			if (ret) {
++				if (ret != -EPROBE_DEFER)
++					pr_err("%s probe fail\n", __func__);
++
++				mtk_cpu_dvfs_info_release();
++				return ret;
++			}
++		}
++	}
++
++	ret = cpufreq_register_driver(&mt8173_cpufreq_driver);
++	if (ret) {
++		pr_err("failed to register mtk cpufreq driver\n");
++		mtk_cpu_dvfs_info_release();
++	}
++
++	return ret;
++}
++
++static struct platform_driver mt8173_cpufreq_platdrv = {
++	.driver = {
++		.name	= "mt8173-cpufreq",
++	},
++	.probe		= mt8173_cpufreq_probe,
++};
++module_platform_driver(mt8173_cpufreq_platdrv);
++
++static int mt8173_cpufreq_driver_init(void)
++{
++	struct platform_device *pdev;
++
++	if (!of_machine_is_compatible("mediatek,mt8173"))
++		return -ENODEV;
++
++	pdev = platform_device_register_simple("mt8173-cpufreq", -1, NULL, 0);
++	if (IS_ERR(pdev)) {
++		pr_err("failed to register mtk-cpufreq platform device\n");
++		return PTR_ERR(pdev);
++	}
++
++	return 0;
++}
++module_init(mt8173_cpufreq_driver_init);
+-- 
+1.7.10.4
+