+++ /dev/null
-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
-
---- 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
---- a/drivers/cpufreq/Makefile
-+++ b/drivers/cpufreq/Makefile
-@@ -63,6 +63,7 @@ obj-$(CONFIG_ARM_HISI_ACPU_CPUFREQ) += h
- obj-$(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
---- /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);
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