diff options
Diffstat (limited to 'drivers/devfreq/mtk-cci-devfreq.c')
| -rw-r--r-- | drivers/devfreq/mtk-cci-devfreq.c | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/drivers/devfreq/mtk-cci-devfreq.c b/drivers/devfreq/mtk-cci-devfreq.c new file mode 100644 index 000000000..e5458ada5 --- /dev/null +++ b/drivers/devfreq/mtk-cci-devfreq.c @@ -0,0 +1,444 @@ +// 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\n"); + } + + 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\n"); + } + + 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\n"); + } + + 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)) { + ret = PTR_ERR(drv->sram_reg); + if (ret == -EPROBE_DEFER) + goto out_free_resources; + + 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"); |