@@ -91,6 +91,16 @@ config ARM_EXYNOS_BUS_DEVFREQ
and adjusts the operating frequencies and voltages with OPP support.
This does not yet operate with optimal voltages.
+config ARM_MT8183_CCI_DEVFREQ
+ tristate "MT8183 CCI DEVFREQ Driver"
+ depends on ARM_MEDIATEK_CPUFREQ
+ help
+ This adds a devfreq driver for Cache Coherent Interconnect
+ of Mediatek MT8183, which is shared the same regulator
+ with cpu cluster.
+ It can track buck voltage and update a proper cci frequency.
+ Use notification to get regulator status.
+
config ARM_TEGRA_DEVFREQ
tristate "Tegra DEVFREQ Driver"
depends on ARCH_TEGRA_124_SOC
@@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o
# DEVFREQ Drivers
obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o
+obj-$(CONFIG_ARM_MT8183_CCI_DEVFREQ) += mt8183-cci-devfreq.o
obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o
new file mode 100644
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 MediaTek Inc.
+
+ * Author: Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/devfreq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+#include "governor.h"
+
+struct cci_devfreq {
+ struct devfreq *devfreq;
+ struct regulator *proc_reg;
+ unsigned long proc_reg_uV;
+ struct clk *cci_clk;
+ struct notifier_block nb;
+};
+
+static int cci_devfreq_regulator_notifier(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ int ret;
+ struct cci_devfreq *cci_df =
+ container_of(nb, struct cci_devfreq, nb);
+
+ /* deal with reduce frequency */
+ if (val & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) {
+ struct pre_voltage_change_data *pvc_data = data;
+
+ if (pvc_data->min_uV < pvc_data->old_uV) {
+ cci_df->proc_reg_uV =
+ (unsigned long)(pvc_data->min_uV);
+ mutex_lock(&cci_df->devfreq->lock);
+ ret = update_devfreq(cci_df->devfreq);
+ if (ret)
+ pr_err("Fail to reduce cci frequency: %d\n",
+ ret);
+ mutex_unlock(&cci_df->devfreq->lock);
+ }
+ } else if ((val & REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE) &&
+ ((unsigned long)data > cci_df->proc_reg_uV)) {
+ cci_df->proc_reg_uV = (unsigned long)data;
+ mutex_lock(&cci_df->devfreq->lock);
+ ret = update_devfreq(cci_df->devfreq);
+ if (ret)
+ pr_err("Fail to raise cci frequency back: %d\n", ret);
+ mutex_unlock(&cci_df->devfreq->lock);
+ } else if ((val & REGULATOR_EVENT_VOLTAGE_CHANGE) &&
+ (cci_df->proc_reg_uV < (unsigned long)data)) {
+ /* deal with increase frequency */
+ cci_df->proc_reg_uV = (unsigned long)data;
+ mutex_lock(&cci_df->devfreq->lock);
+ ret = update_devfreq(cci_df->devfreq);
+ if (ret)
+ pr_err("Fail to raise cci frequency: %d\n", ret);
+ mutex_unlock(&cci_df->devfreq->lock);
+ }
+
+ return 0;
+}
+
+static int mtk_cci_governor_get_target(struct devfreq *devfreq,
+ unsigned long *freq)
+{
+ struct cci_devfreq *cci_df;
+ struct dev_pm_opp *opp;
+
+ cci_df = dev_get_drvdata(devfreq->dev.parent);
+
+ /* find available frequency */
+ opp = dev_pm_opp_find_freq_ceil_by_volt(devfreq->dev.parent,
+ cci_df->proc_reg_uV);
+ *freq = dev_pm_opp_get_freq(opp);
+
+ return 0;
+}
+
+static int mtk_cci_governor_event_handler(struct devfreq *devfreq,
+ unsigned int event, void *data)
+{
+ int ret;
+ struct cci_devfreq *cci_df;
+ struct notifier_block *nb;
+
+ cci_df = dev_get_drvdata(devfreq->dev.parent);
+ nb = &cci_df->nb;
+
+ switch (event) {
+ case DEVFREQ_GOV_START:
+ case DEVFREQ_GOV_RESUME:
+ nb->notifier_call = cci_devfreq_regulator_notifier;
+ ret = regulator_register_notifier(cci_df->proc_reg,
+ nb);
+ if (ret)
+ pr_err("%s: failed to add governor: %d\n", __func__,
+ ret);
+ break;
+
+ case DEVFREQ_GOV_STOP:
+ case DEVFREQ_GOV_SUSPEND:
+ ret = regulator_unregister_notifier(cci_df->proc_reg,
+ nb);
+ if (ret)
+ pr_err("%s: failed to add governor: %d\n", __func__,
+ ret);
+ break;
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static struct devfreq_governor mtk_cci_devfreq_governor = {
+ .name = "mtk_cci_vmon",
+ .get_target_freq = mtk_cci_governor_get_target,
+ .event_handler = mtk_cci_governor_event_handler,
+ .immutable = true
+};
+
+static int mtk_cci_devfreq_target(struct device *dev, unsigned long *freq,
+ u32 flags)
+{
+ int ret;
+ struct cci_devfreq *cci_df = dev_get_drvdata(dev);
+
+ if (!cci_df)
+ return -EINVAL;
+
+ ret = clk_set_rate(cci_df->cci_clk, *freq);
+ if (ret) {
+ pr_err("%s: failed cci to set rate: %d\n", __func__,
+ ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static struct devfreq_dev_profile cci_devfreq_profile = {
+ .target = mtk_cci_devfreq_target,
+};
+
+static int mtk_cci_devfreq_probe(struct platform_device *pdev)
+{
+ struct device *cci_dev = &pdev->dev;
+ struct cci_devfreq *cci_df;
+ int ret;
+
+ cci_df = devm_kzalloc(cci_dev, sizeof(*cci_df), GFP_KERNEL);
+ if (!cci_df)
+ return -ENOMEM;
+
+ cci_df->cci_clk = devm_clk_get(cci_dev, "cci_clock");
+ ret = PTR_ERR_OR_ZERO(cci_df->cci_clk);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(cci_dev, "failed to get clock for CCI: %d\n",
+ ret);
+ return ret;
+ }
+ cci_df->proc_reg = devm_regulator_get_optional(cci_dev, "proc");
+ ret = PTR_ERR_OR_ZERO(cci_df->proc_reg);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(cci_dev, "failed to get regulator for CCI: %d\n",
+ ret);
+ return ret;
+ }
+
+ ret = dev_pm_opp_of_add_table(cci_dev);
+ if (ret) {
+ dev_err(cci_dev, "Fail to init CCI OPP table: %d\n", ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, cci_df);
+
+ cci_df->devfreq = devm_devfreq_add_device(cci_dev,
+ &cci_devfreq_profile,
+ "mtk_cci_vmon",
+ NULL);
+ if (IS_ERR(cci_df->devfreq)) {
+ ret = PTR_ERR(cci_df->devfreq);
+ dev_err(cci_dev, "cannot create cci devfreq device:%d\n", ret);
+ dev_pm_opp_of_remove_table(cci_dev);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const __maybe_unused struct of_device_id
+ mediatek_cci_devfreq_of_match[] = {
+ { .compatible = "mediatek,mt8183-cci" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, mediatek_cci_devfreq_of_match);
+
+static struct platform_driver cci_devfreq_driver = {
+ .probe = mtk_cci_devfreq_probe,
+ .driver = {
+ .name = "mediatek-cci-devfreq",
+ .of_match_table = of_match_ptr(mediatek_cci_devfreq_of_match),
+ },
+};
+
+static int __init mtk_cci_devfreq_init(void)
+{
+ int ret;
+
+ ret = devfreq_add_governor(&mtk_cci_devfreq_governor);
+ if (ret) {
+ pr_err("%s: failed to add governor: %d\n", __func__, ret);
+ return ret;
+ }
+
+ ret = platform_driver_register(&cci_devfreq_driver);
+ if (ret)
+ devfreq_remove_governor(&mtk_cci_devfreq_governor);
+
+ return ret;
+}
+module_init(mtk_cci_devfreq_init)
+
+static void __exit mtk_cci_devfreq_exit(void)
+{
+ int ret;
+
+ ret = devfreq_remove_governor(&mtk_cci_devfreq_governor);
+ if (ret)
+ pr_err("%s: failed to remove governor: %d\n", __func__, ret);
+
+ platform_driver_unregister(&cci_devfreq_driver);
+}
+module_exit(mtk_cci_devfreq_exit)
+
+MODULE_DESCRIPTION("Mediatek CCI devfreq driver");
+MODULE_AUTHOR("Andrew-sh.Cheng <andrew-sh.cheng@mediatek.com>");
+MODULE_LICENSE("GPL v2");