@@ -0,0 +1,337 @@
+/*
+ * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
+ * Author: Lin Huang <hl@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/completion.h>
+#include <linux/delay.h>
+#include <linux/devfreq.h>
+#include <linux/devfreq-event.h>
+#include <linux/interrupt.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/rwsem.h>
+#include <linux/suspend.h>
+#include <linux/syscore_ops.h>
+
+#include <soc/rockchip/rockchip_dmc.h>
+
+struct rk3399_dmcfreq {
+ struct device *dev;
+ struct devfreq *devfreq;
+ struct devfreq_simple_ondemand_data ondemand_data;
+ struct clk *dmc_clk;
+ struct completion dcf_hold_completion;
+ struct devfreq_event_dev *edev;
+ struct mutex lock;
+ struct notifier_block dmc_nb;
+ int irq;
+ struct regulator *vdd_center;
+ unsigned long rate, target_rate;
+ unsigned long volt, target_volt;
+};
+
+static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq,
+ u32 flags)
+{
+ struct platform_device *pdev = container_of(dev, struct platform_device,
+ dev);
+ struct rk3399_dmcfreq *dmcfreq = platform_get_drvdata(pdev);
+ struct dev_pm_opp *opp;
+ unsigned long old_clk_rate = dmcfreq->rate;
+ unsigned long target_volt, target_rate;
+ int err;
+
+ rcu_read_lock();
+ opp = devfreq_recommended_opp(dev, freq, flags);
+ if (IS_ERR(opp)) {
+ rcu_read_unlock();
+ return PTR_ERR(opp);
+ }
+ target_rate = dev_pm_opp_get_freq(opp);
+ target_volt = dev_pm_opp_get_voltage(opp);
+ opp = devfreq_recommended_opp(dev, &dmcfreq->rate, flags);
+ if (IS_ERR(opp)) {
+ rcu_read_unlock();
+ return PTR_ERR(opp);
+ }
+ dmcfreq->volt = dev_pm_opp_get_voltage(opp);
+ rcu_read_unlock();
+
+ if (dmcfreq->rate == target_rate)
+ return 0;
+
+ mutex_lock(&dmcfreq->lock);
+
+ /*
+ * if frequency scaling from low to high, adjust voltage first;
+ * if frequency scaling from high to low, adjuset frequency first;
+ */
+ if (old_clk_rate < target_rate) {
+ err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
+ target_volt);
+ if (err) {
+ dev_err(dev, "Unable to set vol %lu\n", target_volt);
+ goto out;
+ }
+ }
+
+ dmc_event(DMCFREQ_ADJUST);
+ reinit_completion(&dmcfreq->dcf_hold_completion);
+ err = clk_set_rate(dmcfreq->dmc_clk, target_rate);
+ if (err) {
+ dev_err(dev,
+ "Unable to set freq %lu. Current freq %lu. Error %d\n",
+ target_rate, old_clk_rate, err);
+ regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
+ dmcfreq->volt);
+ dmc_event(DMCFREQ_FINISH);
+ goto out;
+ }
+
+ /* wait until bcf irq happen, it means freq scaling finish in bl31 */
+ wait_for_completion(&dmcfreq->dcf_hold_completion);
+ dmc_event(DMCFREQ_FINISH);
+
+ /*
+ * check the rate we get whether is correct
+ * in bl31 dcf, there only two result we will get,
+ * 1. ddr frequency scaling fail, we still get the old rate
+ * 2, ddr frequency scaling sucessful, we get the rate we set
+ */
+ dmcfreq->rate = clk_get_rate(dmcfreq->dmc_clk);
+
+ /* do not get the right rate, set voltage to old value */
+ if (dmcfreq->rate != target_rate) {
+ dev_err(dev, "get wrong ddr frequency, Request freq %lu,\
+ Current freq %lu\n", target_rate, dmcfreq->rate);
+ regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
+ dmcfreq->volt);
+ } else if (old_clk_rate > target_rate)
+ err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
+ target_volt);
+ if (err)
+ dev_err(dev, "Unable to set vol %lu\n", target_volt);
+
+out:
+ mutex_unlock(&dmcfreq->lock);
+ return err;
+}
+
+static int rk3399_dmcfreq_get_dev_status(struct device *dev,
+ struct devfreq_dev_status *stat)
+{
+ struct platform_device *pdev = container_of(dev, struct platform_device,
+ dev);
+ struct rk3399_dmcfreq *dmcfreq = platform_get_drvdata(pdev);
+ struct devfreq_event_data edata;
+
+ devfreq_event_get_event(dmcfreq->edev, &edata);
+
+ stat->current_frequency = dmcfreq->rate;
+ stat->busy_time = edata.load_count;
+ stat->total_time = edata.total_count;
+
+ return 0;
+}
+
+static int rk3399_dmcfreq_get_cur_freq(struct device *dev, unsigned long *freq)
+{
+ struct platform_device *pdev = container_of(dev, struct platform_device,
+ dev);
+ struct rk3399_dmcfreq *dmcfreq = platform_get_drvdata(pdev);
+
+ *freq = dmcfreq->rate;
+
+ return 0;
+}
+
+static void rk3399_dmcfreq_exit(struct device *dev)
+{
+ struct platform_device *pdev = container_of(dev, struct platform_device,
+ dev);
+ struct rk3399_dmcfreq *dmcfreq = platform_get_drvdata(pdev);
+
+ devfreq_unregister_opp_notifier(dev, dmcfreq->devfreq);
+}
+
+static struct devfreq_dev_profile rk3399_devfreq_dmc_profile = {
+ .polling_ms = 200,
+ .target = rk3399_dmcfreq_target,
+ .get_dev_status = rk3399_dmcfreq_get_dev_status,
+ .get_cur_freq = rk3399_dmcfreq_get_cur_freq,
+ .exit = rk3399_dmcfreq_exit,
+};
+
+static __maybe_unused int rk3399_dmcfreq_suspend(struct device *dev)
+{
+ rockchip_dmc_disable();
+ return 0;
+}
+
+static __maybe_unused int rk3399_dmcfreq_resume(struct device *dev)
+{
+ rockchip_dmc_enable();
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rk3399_dmcfreq_pm, rk3399_dmcfreq_suspend,
+ rk3399_dmcfreq_resume);
+
+static int rk3399_dmc_enable_notify(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct rk3399_dmcfreq *dmcfreq =
+ container_of(nb, struct rk3399_dmcfreq, dmc_nb);
+ unsigned long freq = ULONG_MAX;
+
+ if (event == DMC_ENABLE) {
+ devfreq_event_enable_edev(dmcfreq->edev);
+ devfreq_resume_device(dmcfreq->devfreq);
+ return NOTIFY_OK;
+ } else if (event == DMC_DISABLE) {
+ devfreq_event_disable_edev(dmcfreq->edev);
+ devfreq_suspend_device(dmcfreq->devfreq);
+
+ /* when disable dmc, set sdram to max frequency */
+ rk3399_dmcfreq_target(dmcfreq->dev, &freq, 0);
+ return NOTIFY_OK;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static irqreturn_t rk3399_dmc_irq(int irq, void *dev_id)
+{
+ struct rk3399_dmcfreq *dmcfreq = dev_id;
+
+ complete(&dmcfreq->dcf_hold_completion);
+
+ return IRQ_HANDLED;
+}
+
+static int rk3399_dmcfreq_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rk3399_dmcfreq *data;
+ int ret, irq;
+ struct device_node *np = pdev->dev.of_node;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no dmc irq resource\n");
+ return -EINVAL;
+ }
+
+ data = devm_kzalloc(dev, sizeof(struct rk3399_dmcfreq), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ mutex_init(&data->lock);
+
+ data->vdd_center = devm_regulator_get(dev, "center");
+ if (IS_ERR(data->vdd_center)) {
+ dev_err(dev, "Cannot get the regulator \"center\"\n");
+ return PTR_ERR(data->vdd_center);
+ }
+
+ data->dmc_clk = devm_clk_get(dev, "dmc_clk");
+ if (IS_ERR(data->dmc_clk)) {
+ dev_err(dev, "Cannot get the clk dmc_clk\n");
+ return PTR_ERR(data->dmc_clk);
+ };
+
+ data->edev = devfreq_event_get_edev_by_phandle(dev, 0);
+ if (IS_ERR(data->edev))
+ return -EPROBE_DEFER;
+
+ ret = devfreq_event_enable_edev(data->edev);
+ if (ret < 0) {
+ dev_err(dev, "failed to enable devfreq-event devices\n");
+ return ret;
+ }
+
+ /*
+ * We add a devfreq driver to our parent since it has a device tree node
+ * with operating points.
+ */
+ if (dev_pm_opp_of_add_table(dev)) {
+ dev_err(dev, "Invalid operating-points in device tree.\n");
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "upthreshold",
+ &data->ondemand_data.upthreshold);
+
+ of_property_read_u32(np, "downdifferential",
+ &data->ondemand_data.downdifferential);
+
+ data->devfreq = devfreq_add_device(dev,
+ &rk3399_devfreq_dmc_profile,
+ "simple_ondemand",
+ &data->ondemand_data);
+ if (IS_ERR(data->devfreq))
+ return PTR_ERR(data->devfreq);
+
+ devfreq_register_opp_notifier(dev, data->devfreq);
+
+ data->dmc_nb.notifier_call = rk3399_dmc_enable_notify;
+ dmc_register_notifier(&data->dmc_nb);
+
+ init_completion(&data->dcf_hold_completion);
+
+ data->irq = irq;
+ ret = devm_request_irq(dev, irq, rk3399_dmc_irq, 0,
+ dev_name(dev), data);
+ if (ret) {
+ dev_err(dev, "failed to request dmc irq: %d\n", ret);
+ return ret;
+ }
+
+ data->dev = dev;
+ platform_set_drvdata(pdev, data);
+
+ return 0;
+}
+
+static int rk3399_dmcfreq_remove(struct platform_device *pdev)
+{
+ struct rk3399_dmcfreq *dmcfreq = platform_get_drvdata(pdev);
+
+ devfreq_remove_device(dmcfreq->devfreq);
+ regulator_put(dmcfreq->vdd_center);
+
+ return 0;
+}
+
+static const struct of_device_id rk3399dmc_devfreq_of_match[] = {
+ { .compatible = "rockchip,rk3399-dmc" },
+ { },
+};
+
+static struct platform_driver rk3399_dmcfreq_driver = {
+ .probe = rk3399_dmcfreq_probe,
+ .remove = rk3399_dmcfreq_remove,
+ .driver = {
+ .name = "rk3399-dmc-freq",
+ .pm = &rk3399_dmcfreq_pm,
+ .of_match_table = rk3399dmc_devfreq_of_match,
+ },
+};
+module_platform_driver(rk3399_dmcfreq_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("RK3399 dmcfreq driver with devfreq framework");