@@ -120,6 +120,16 @@ config ARM_TEGRA_DEVFREQ
It reads ACTMON counters of memory controllers and adjusts the
operating frequencies and voltages with OPP support.
+config ARM_MEDIATEK_CCI_DEVFREQ
+ tristate "MEDIATEK CCI DEVFREQ Driver"
+ depends on ARM_MEDIATEK_CPUFREQ || COMPILE_TEST
+ select DEVFREQ_GOV_PASSIVE
+ help
+ This adds a devfreq driver for MediaTek Cache Coherent Interconnect
+ which is shared the same regulators with the cpu cluster. It can track
+ buck voltages and update a proper CCI frequency. Use the notification
+ to get the regulator status.
+
config ARM_RK3399_DMC_DEVFREQ
tristate "ARM RK3399 DMC DEVFREQ Driver"
depends on (ARCH_ROCKCHIP && HAVE_ARM_SMCCC) || \
@@ -11,6 +11,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o
obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o
obj-$(CONFIG_ARM_IMX_BUS_DEVFREQ) += imx-bus.o
obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ) += imx8m-ddrc.o
+obj-$(CONFIG_ARM_MEDIATEK_CCI_DEVFREQ) += mtk-cci-devfreq.o
obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
obj-$(CONFIG_ARM_SUN8I_A33_MBUS_DEVFREQ) += sun8i-a33-mbus.o
obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra30-devfreq.o
new file mode 100644
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 MediaTek Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/devfreq.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regulator/consumer.h>
+
+struct mtk_ccifreq_platform_data {
+ int min_volt_shift;
+ int max_volt_shift;
+ int proc_max_volt;
+ int sram_min_volt;
+ int sram_max_volt;
+};
+
+struct mtk_ccifreq_drv {
+ struct device *dev;
+ struct devfreq *devfreq;
+ struct regulator *proc_reg;
+ struct regulator *sram_reg;
+ struct clk *cci_clk;
+ struct clk *inter_clk;
+ int inter_voltage;
+ unsigned long pre_freq;
+ /* Avoid race condition for regulators between notify and policy */
+ struct mutex reg_lock;
+ struct notifier_block opp_nb;
+ const struct mtk_ccifreq_platform_data *soc_data;
+ int vtrack_max;
+};
+
+static int mtk_ccifreq_set_voltage(struct mtk_ccifreq_drv *drv, int new_voltage)
+{
+ const struct mtk_ccifreq_platform_data *soc_data = drv->soc_data;
+ struct device *dev = drv->dev;
+ int pre_voltage, pre_vsram, new_vsram, vsram, voltage, ret;
+ int retry_max = drv->vtrack_max;
+
+ if (!drv->sram_reg) {
+ ret = regulator_set_voltage(drv->proc_reg, new_voltage,
+ drv->soc_data->proc_max_volt);
+ return ret;
+ }
+
+ pre_voltage = regulator_get_voltage(drv->proc_reg);
+ if (pre_voltage < 0) {
+ dev_err(dev, "invalid vproc value: %d\n", pre_voltage);
+ return pre_voltage;
+ }
+
+ pre_vsram = regulator_get_voltage(drv->sram_reg);
+ if (pre_vsram < 0) {
+ dev_err(dev, "invalid vsram value: %d\n", pre_vsram);
+ return pre_vsram;
+ }
+
+ new_vsram = clamp(new_voltage + soc_data->min_volt_shift,
+ soc_data->sram_min_volt, soc_data->sram_max_volt);
+
+ do {
+ if (pre_voltage <= new_voltage) {
+ vsram = clamp(pre_voltage + soc_data->max_volt_shift,
+ soc_data->sram_min_volt, new_vsram);
+ ret = regulator_set_voltage(drv->sram_reg, vsram,
+ soc_data->sram_max_volt);
+ if (ret)
+ return ret;
+
+ if (vsram == soc_data->sram_max_volt ||
+ new_vsram == soc_data->sram_min_volt)
+ voltage = new_voltage;
+ else
+ voltage = vsram - soc_data->min_volt_shift;
+
+ ret = regulator_set_voltage(drv->proc_reg, voltage,
+ soc_data->proc_max_volt);
+ if (ret) {
+ regulator_set_voltage(drv->sram_reg, pre_vsram,
+ soc_data->sram_max_volt);
+ return ret;
+ }
+ } else if (pre_voltage > new_voltage) {
+ voltage = max(new_voltage,
+ pre_vsram - soc_data->max_volt_shift);
+ ret = regulator_set_voltage(drv->proc_reg, voltage,
+ soc_data->proc_max_volt);
+ if (ret)
+ return ret;
+
+ if (voltage == new_voltage)
+ vsram = new_vsram;
+ else
+ vsram = max(new_vsram,
+ voltage + soc_data->min_volt_shift);
+
+ ret = regulator_set_voltage(drv->sram_reg, vsram,
+ soc_data->sram_max_volt);
+ if (ret) {
+ regulator_set_voltage(drv->proc_reg, pre_voltage,
+ soc_data->proc_max_volt);
+ return ret;
+ }
+ }
+
+ pre_voltage = voltage;
+ pre_vsram = vsram;
+
+ if (--retry_max < 0) {
+ dev_err(dev,
+ "over loop count, failed to set voltage\n");
+ return -EINVAL;
+ }
+ } while (voltage != new_voltage || vsram != new_vsram);
+
+ return 0;
+}
+
+static int mtk_ccifreq_target(struct device *dev, unsigned long *freq,
+ u32 flags)
+{
+ struct mtk_ccifreq_drv *drv = dev_get_drvdata(dev);
+ struct clk *cci_pll = clk_get_parent(drv->cci_clk);
+ struct dev_pm_opp *opp;
+ unsigned long opp_rate;
+ int voltage, pre_voltage, inter_voltage, target_voltage, ret;
+
+ if (!drv)
+ return -EINVAL;
+
+ if (drv->pre_freq == *freq)
+ return 0;
+
+ inter_voltage = drv->inter_voltage;
+
+ opp_rate = *freq;
+ opp = devfreq_recommended_opp(dev, &opp_rate, 1);
+ if (IS_ERR(opp)) {
+ dev_err(dev, "failed to find opp for freq: %ld\n", opp_rate);
+ return PTR_ERR(opp);
+ }
+
+ mutex_lock(&drv->reg_lock);
+
+ voltage = dev_pm_opp_get_voltage(opp);
+ dev_pm_opp_put(opp);
+
+ pre_voltage = regulator_get_voltage(drv->proc_reg);
+ if (pre_voltage < 0) {
+ dev_err(dev, "invalid vproc value: %d\n", pre_voltage);
+ ret = pre_voltage;
+ goto out_unlock;
+ }
+
+ /* scale up: set voltage first then freq. */
+ target_voltage = max(inter_voltage, voltage);
+ if (pre_voltage <= target_voltage) {
+ ret = mtk_ccifreq_set_voltage(drv, target_voltage);
+ if (ret) {
+ dev_err(dev, "failed to scale up voltage\n");
+ goto out_restore_voltage;
+ }
+ }
+
+ /* switch the cci clock to intermediate clock source. */
+ ret = clk_set_parent(drv->cci_clk, drv->inter_clk);
+ if (ret) {
+ dev_err(dev, "failed to re-parent cci clock\n");
+ goto out_restore_voltage;
+ }
+
+ /* set the original clock to target rate. */
+ ret = clk_set_rate(cci_pll, *freq);
+ if (ret) {
+ dev_err(dev, "failed to set cci pll rate: %d\n", ret);
+ clk_set_parent(drv->cci_clk, cci_pll);
+ goto out_restore_voltage;
+ }
+
+ /* switch the cci clock back to the original clock source. */
+ ret = clk_set_parent(drv->cci_clk, cci_pll);
+ if (ret) {
+ dev_err(dev, "failed to re-parent cci clock\n");
+ mtk_ccifreq_set_voltage(drv, inter_voltage);
+ goto out_unlock;
+ }
+
+ /*
+ * If the new voltage is lower than the intermediate voltage or the
+ * original voltage, scale down to the new voltage.
+ */
+ if (voltage < inter_voltage || voltage < pre_voltage) {
+ ret = mtk_ccifreq_set_voltage(drv, voltage);
+ if (ret) {
+ dev_err(dev, "failed to scale down voltage\n");
+ goto out_unlock;
+ }
+ }
+
+ drv->pre_freq = *freq;
+ mutex_unlock(&drv->reg_lock);
+
+ return 0;
+
+out_restore_voltage:
+ mtk_ccifreq_set_voltage(drv, pre_voltage);
+
+out_unlock:
+ mutex_unlock(&drv->reg_lock);
+ return ret;
+}
+
+static int mtk_ccifreq_opp_notifier(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct dev_pm_opp *opp = data;
+ struct mtk_ccifreq_drv *drv;
+ unsigned long freq, volt;
+
+ drv = container_of(nb, struct mtk_ccifreq_drv, opp_nb);
+
+ if (event == OPP_EVENT_ADJUST_VOLTAGE) {
+ freq = dev_pm_opp_get_freq(opp);
+
+ mutex_lock(&drv->reg_lock);
+ /* current opp item is changed */
+ if (freq == drv->pre_freq) {
+ volt = dev_pm_opp_get_voltage(opp);
+ mtk_ccifreq_set_voltage(drv, volt);
+ }
+ mutex_unlock(&drv->reg_lock);
+ }
+
+ return 0;
+}
+
+static struct devfreq_dev_profile mtk_ccifreq_profile = {
+ .target = mtk_ccifreq_target,
+};
+
+static int mtk_ccifreq_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mtk_ccifreq_drv *drv;
+ struct devfreq_passive_data *passive_data;
+ struct dev_pm_opp *opp;
+ unsigned long rate, opp_volt;
+ int ret;
+
+ drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->dev = dev;
+ drv->soc_data = (const struct mtk_ccifreq_platform_data *)
+ of_device_get_match_data(&pdev->dev);
+ mutex_init(&drv->reg_lock);
+ platform_set_drvdata(pdev, drv);
+
+ drv->cci_clk = devm_clk_get(dev, "cci");
+ if (IS_ERR(drv->cci_clk)) {
+ ret = PTR_ERR(drv->cci_clk);
+ return dev_err_probe(dev, ret,
+ "failed to get cci clk: %d\n", ret);
+ }
+
+ drv->inter_clk = devm_clk_get(dev, "intermediate");
+ if (IS_ERR(drv->inter_clk)) {
+ ret = PTR_ERR(drv->inter_clk);
+ return dev_err_probe(dev, ret,
+ "failed to get intermediate clk: %d\n", ret);
+ }
+
+ drv->proc_reg = devm_regulator_get_optional(dev, "proc");
+ if (IS_ERR(drv->proc_reg)) {
+ ret = PTR_ERR(drv->proc_reg);
+ return dev_err_probe(dev, ret,
+ "failed to get proc regulator: %d\n", ret);
+ }
+
+ ret = regulator_enable(drv->proc_reg);
+ if (ret) {
+ dev_err(dev, "failed to enable proc regulator\n");
+ return ret;
+ }
+
+ drv->sram_reg = devm_regulator_get_optional(dev, "sram");
+ if (IS_ERR(drv->sram_reg))
+ drv->sram_reg = NULL;
+ else {
+ ret = regulator_enable(drv->sram_reg);
+ if (ret) {
+ dev_err(dev, "failed to enable sram regulator\n");
+ goto out_free_resources;
+ }
+ }
+
+ /*
+ * We assume min voltage is 0 and tracking target voltage using
+ * min_volt_shift for each iteration.
+ * The retry_max is 3 times of expected iteration count.
+ */
+ drv->vtrack_max = 3 * DIV_ROUND_UP(max(drv->soc_data->sram_max_volt,
+ drv->soc_data->proc_max_volt),
+ drv->soc_data->min_volt_shift);
+
+ ret = clk_prepare_enable(drv->cci_clk);
+ if (ret)
+ goto out_free_resources;
+
+ ret = dev_pm_opp_of_add_table(dev);
+ if (ret) {
+ dev_err(dev, "failed to add opp table: %d\n", ret);
+ goto out_disable_cci_clk;
+ }
+
+ rate = clk_get_rate(drv->inter_clk);
+ opp = dev_pm_opp_find_freq_ceil(dev, &rate);
+ if (IS_ERR(opp)) {
+ ret = PTR_ERR(opp);
+ dev_err(dev, "failed to get intermediate opp: %d\n", ret);
+ goto out_remove_opp_table;
+ }
+ drv->inter_voltage = dev_pm_opp_get_voltage(opp);
+ dev_pm_opp_put(opp);
+
+ rate = U32_MAX;
+ opp = dev_pm_opp_find_freq_floor(drv->dev, &rate);
+ if (IS_ERR(opp)) {
+ dev_err(dev, "failed to get opp\n");
+ ret = PTR_ERR(opp);
+ goto out_remove_opp_table;
+ }
+
+ opp_volt = dev_pm_opp_get_voltage(opp);
+ dev_pm_opp_put(opp);
+ ret = mtk_ccifreq_set_voltage(drv, opp_volt);
+ if (ret) {
+ dev_err(dev, "failed to scale to highest voltage %lu in proc_reg\n",
+ opp_volt);
+ goto out_remove_opp_table;
+ }
+
+ passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
+ if (!passive_data) {
+ ret = -ENOMEM;
+ goto out_remove_opp_table;
+ }
+
+ passive_data->parent_type = CPUFREQ_PARENT_DEV;
+ drv->devfreq = devm_devfreq_add_device(dev, &mtk_ccifreq_profile,
+ DEVFREQ_GOV_PASSIVE,
+ passive_data);
+ if (IS_ERR(drv->devfreq)) {
+ ret = -EPROBE_DEFER;
+ dev_err(dev, "failed to add devfreq device: %ld\n",
+ PTR_ERR(drv->devfreq));
+ goto out_remove_opp_table;
+ }
+
+ drv->opp_nb.notifier_call = mtk_ccifreq_opp_notifier;
+ ret = dev_pm_opp_register_notifier(dev, &drv->opp_nb);
+ if (ret) {
+ dev_err(dev, "failed to register opp notifier: %d\n", ret);
+ goto out_remove_opp_table;
+ }
+ return 0;
+
+out_remove_opp_table:
+ dev_pm_opp_of_remove_table(dev);
+
+out_disable_cci_clk:
+ clk_disable_unprepare(drv->cci_clk);
+
+out_free_resources:
+ if (regulator_is_enabled(drv->proc_reg))
+ regulator_disable(drv->proc_reg);
+ if (drv->sram_reg && regulator_is_enabled(drv->sram_reg))
+ regulator_disable(drv->sram_reg);
+
+ return ret;
+}
+
+static int mtk_ccifreq_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mtk_ccifreq_drv *drv;
+
+ drv = platform_get_drvdata(pdev);
+
+ dev_pm_opp_unregister_notifier(dev, &drv->opp_nb);
+ dev_pm_opp_of_remove_table(dev);
+ clk_disable_unprepare(drv->cci_clk);
+ regulator_disable(drv->proc_reg);
+ if (drv->sram_reg)
+ regulator_disable(drv->sram_reg);
+
+ return 0;
+}
+
+static const struct mtk_ccifreq_platform_data mt8183_platform_data = {
+ .min_volt_shift = 100000,
+ .max_volt_shift = 200000,
+ .proc_max_volt = 1150000,
+};
+
+static const struct mtk_ccifreq_platform_data mt8186_platform_data = {
+ .min_volt_shift = 100000,
+ .max_volt_shift = 250000,
+ .proc_max_volt = 1118750,
+ .sram_min_volt = 850000,
+ .sram_max_volt = 1118750,
+};
+
+static const struct of_device_id mtk_ccifreq_machines[] = {
+ { .compatible = "mediatek,mt8183-cci", .data = &mt8183_platform_data },
+ { .compatible = "mediatek,mt8186-cci", .data = &mt8186_platform_data },
+ { },
+};
+MODULE_DEVICE_TABLE(of, mtk_ccifreq_machines);
+
+static struct platform_driver mtk_ccifreq_platdrv = {
+ .probe = mtk_ccifreq_probe,
+ .remove = mtk_ccifreq_remove,
+ .driver = {
+ .name = "mtk-ccifreq",
+ .of_match_table = mtk_ccifreq_machines,
+ },
+};
+module_platform_driver(mtk_ccifreq_platdrv);
+
+MODULE_DESCRIPTION("MediaTek CCI devfreq driver");
+MODULE_AUTHOR("Jia-Wei Chang <jia-wei.chang@mediatek.com>");
+MODULE_LICENSE("GPL v2");