Re: [PATCH v3 6/7] PM / devfreq: rockchip: add devfreq driver for rk3399 dmc
From: hl
Date: Mon Jul 25 2016 - 04:47:53 EST
Hi Chanwoo Choi,
On 2016å07æ25æ 14:01, Chanwoo Choi wrote:
Hi Lin,
I'm glad to support the for dmc ddr clock scaling with devfreq/devfreq-event.
But, I think that you have to use the standard interface.
As I already mentioned[1] on previous mail, devfreq fwk support
the standard DEVFREQ_TRANSITION_NOTIFIER notifier which has the two notifications.
- DEVFREQ_PRECHANGE
- DEVFREQ_POSTCHANGE
[1] https://patchwork.kernel.org/patch/9194305/
You can use the DEVFREQ_PRECHANGE instead of DMCFREQ_ADJUST
and use the DEVFREQ_POSTCHANGE instead of DMCFREQ_FINISH.
On 2016ë 07ì 22ì 18:07, Lin Huang wrote:
base on dfi result, we do ddr frequency scaling, register
dmc driver to devfreq framework, and use simple-ondemand
policy.
Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx>
---
Changes in v3:
- operate dram setting through sip call
- imporve set rate flow
Changes in v2:
- None
Changes in v1:
- move dfi controller to event
- fix set voltage sequence when set rate fail
- change Kconfig type from tristate to bool
- move unuse EXPORT_SYMBOL_GPL()
drivers/devfreq/Kconfig | 1 +
drivers/devfreq/Makefile | 1 +
drivers/devfreq/rockchip/Kconfig | 15 +
drivers/devfreq/rockchip/Makefile | 2 +
drivers/devfreq/rockchip/rk3399_dmc.c | 482 ++++++++++++++++++++++++++++++++
drivers/devfreq/rockchip/rockchip_dmc.c | 143 ++++++++++
include/soc/rockchip/rockchip_dmc.h | 45 +++
7 files changed, 689 insertions(+)
create mode 100644 drivers/devfreq/rockchip/Kconfig
create mode 100644 drivers/devfreq/rockchip/Makefile
create mode 100644 drivers/devfreq/rockchip/rk3399_dmc.c
create mode 100644 drivers/devfreq/rockchip/rockchip_dmc.c
create mode 100644 include/soc/rockchip/rockchip_dmc.h
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index a5be56e..cb67246 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -101,5 +101,6 @@ config ARM_TEGRA_DEVFREQ
operating frequencies and voltages with OPP support.
source "drivers/devfreq/event/Kconfig"
+source "drivers/devfreq/rockchip/Kconfig"
endif # PM_DEVFREQ
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
index 09f11d9..48e2ae6 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o
# DEVFREQ Drivers
obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o
obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o
+obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
# DEVFREQ Event Drivers
obj-$(CONFIG_PM_DEVFREQ_EVENT) += event/
diff --git a/drivers/devfreq/rockchip/Kconfig b/drivers/devfreq/rockchip/Kconfig
new file mode 100644
index 0000000..7fb1cff
--- /dev/null
+++ b/drivers/devfreq/rockchip/Kconfig
@@ -0,0 +1,15 @@
+config ARM_ROCKCHIP_DMC_DEVFREQ
+ bool "ARM ROCKCHIP DMC DEVFREQ Driver"
+ depends on ARCH_ROCKCHIP
+ help
+ This adds the DEVFREQ driver framework for the rockchip dmc.
+
+config ARM_RK3399_DMC_DEVFREQ
+ bool "ARM RK3399 DMC DEVFREQ Driver"
+ depends on ARM_ROCKCHIP_DMC_DEVFREQ
+ select PM_OPP
+ select DEVFREQ_GOV_SIMPLE_ONDEMAND
+ help
+ This adds the DEVFREQ driver for the RK3399 dmc. It sets the frequency
+ for the memory controller and reads the usage counts from hardware.
+
diff --git a/drivers/devfreq/rockchip/Makefile b/drivers/devfreq/rockchip/Makefile
new file mode 100644
index 0000000..caca525
--- /dev/null
+++ b/drivers/devfreq/rockchip/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_ARM_ROCKCHIP_DMC_DEVFREQ) += rockchip_dmc.o
+obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
diff --git a/drivers/devfreq/rockchip/rk3399_dmc.c b/drivers/devfreq/rockchip/rk3399_dmc.c
new file mode 100644
index 0000000..f1d6120
--- /dev/null
+++ b/drivers/devfreq/rockchip/rk3399_dmc.c
@@ -0,0 +1,482 @@
+/*
+ * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
+ * Author: Lin Huang <hl@xxxxxxxxxxxxxx>
+ *
+ * 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>
+#include "../../firmware/rockchip_sip.h"
+
+struct dram_timing {
+ unsigned int ddr3_speed_bin;
+ unsigned int pd_idle;
+ unsigned int sr_idle;
+ unsigned int sr_mc_gate_idle;
+ unsigned int srpd_lite_idle;
+ unsigned int standby_idle;
+ unsigned int dram_dll_dis_freq;
+ unsigned int phy_dll_dis_freq;
+ unsigned int ddr3_odt_dis_freq;
+ unsigned int ddr3_drv;
+ unsigned int ddr3_odt;
+ unsigned int phy_ddr3_ca_drv;
+ unsigned int phy_ddr3_dq_drv;
+ unsigned int phy_ddr3_odt;
+ unsigned int lpddr3_odt_dis_freq;
+ unsigned int lpddr3_drv;
+ unsigned int lpddr3_odt;
+ unsigned int phy_lpddr3_ca_drv;
+ unsigned int phy_lpddr3_dq_drv;
+ unsigned int phy_lpddr3_odt;
+ unsigned int lpddr4_odt_dis_freq;
+ unsigned int lpddr4_drv;
+ unsigned int lpddr4_dq_odt;
+ unsigned int lpddr4_ca_odt;
+ unsigned int phy_lpddr4_ca_drv;
+ unsigned int phy_lpddr4_ck_cs_drv;
+ unsigned int phy_lpddr4_dq_drv;
+ unsigned int phy_lpddr4_odt;
+};
+
+struct rk3399_dmcfreq {
+ struct device *dev;
+ struct devfreq *devfreq;
+ struct devfreq_simple_ondemand_data ondemand_data;
+ struct clk *dmc_clk;
+ struct devfreq_event_dev *edev;
+ struct mutex lock;
+ struct notifier_block dmc_nb;
+ struct dram_timing *timing;
+ wait_queue_head_t wait_dcf_queue;
+ int irq;
+ int wait_dcf_flag;
+ 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);
You don't need to send the notification in target function.
When you use the DEVFREQ_TRANSITION_NOTIFIER notifier,
devfreq send the notification before calling the target() and after calling the target().
I checked DEVFREQ_TRANSISTION_NOTIFIER notifier before, but i have some
question:
Now i want to use
DEVFREQ_PRECHANGE and DEVFREQ_POSTCHANGE in vop driver, but it hard
to get the *devfreq
in vop driver, or i can register a DEVFREQ_TRANSITION_NOTIFIER notifier
in rk3399_dmc.c and
when get message, post DEVFREQ_PRECHANGE or DEVFREQ_POSTCHANGE to vop
driver through dmc_event(),
do you have a better way to do it?
+ dmcfreq->wait_dcf_flag = 1;
+
+ 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);
ditto.
+ goto out;
+ }
+
+ /*
+ * wait until bcf irq happen, it means freq scaling finish in bl31,
+ * use 100ms as timeout time
+ */
+ wait_event_timeout(dmcfreq->wait_dcf_queue,
+ !dmcfreq->wait_dcf_flag, HZ / 10);
+
+ dmc_event(DMCFREQ_FINISH);
ditto.
+
+ /*
+ * check the dpll rate
+ * 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);
+
+ /* if get the incorrect 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;
+
+ dmcfreq->wait_dcf_flag = 0;
+ wake_up(&dmcfreq->wait_dcf_queue);
+
+ /* clr dcf irq */
+ sip_smc_clr_ddr_irq();
+
+ return IRQ_HANDLED;
+}
+
+static int of_do_get_timing(struct device_node *np,
+ struct dram_timing *timing)
+{
+ int ret;
+
+ ret = of_property_read_u32(np, "ddr3_speed_bin",
+ &timing->ddr3_speed_bin);
+ ret |= of_property_read_u32(np, "pd_idle", &timing->pd_idle);
+ ret |= of_property_read_u32(np, "sr_idle", &timing->sr_idle);
+ ret |= of_property_read_u32(np, "sr_mc_gate_idle",
+ &timing->sr_mc_gate_idle);
+ ret |= of_property_read_u32(np, "srpd_lite_idle",
+ &timing->srpd_lite_idle);
+ ret |= of_property_read_u32(np, "standby_idle", &timing->standby_idle);
+ ret |= of_property_read_u32(np, "dram_dll_dis_freq",
+ &timing->dram_dll_dis_freq);
+ ret |= of_property_read_u32(np, "phy_dll_dis_freq",
+ &timing->phy_dll_dis_freq);
+ ret |= of_property_read_u32(np, "ddr3_odt_dis_freq",
+ &timing->ddr3_odt_dis_freq);
+ ret |= of_property_read_u32(np, "ddr3_drv", &timing->ddr3_drv);
+ ret |= of_property_read_u32(np, "ddr3_odt", &timing->ddr3_odt);
+ ret |= of_property_read_u32(np, "phy_ddr3_ca_drv",
+ &timing->phy_ddr3_ca_drv);
+ ret |= of_property_read_u32(np, "phy_ddr3_dq_drv",
+ &timing->phy_ddr3_dq_drv);
+ ret |= of_property_read_u32(np, "phy_ddr3_odt", &timing->phy_ddr3_odt);
+ ret |= of_property_read_u32(np, "lpddr3_odt_dis_freq",
+ &timing->lpddr3_odt_dis_freq);
+ ret |= of_property_read_u32(np, "lpddr3_drv", &timing->lpddr3_drv);
+ ret |= of_property_read_u32(np, "lpddr3_odt", &timing->lpddr3_odt);
+ ret |= of_property_read_u32(np, "phy_lpddr3_ca_drv",
+ &timing->phy_lpddr3_ca_drv);
+ ret |= of_property_read_u32(np, "phy_lpddr3_dq_drv",
+ &timing->phy_lpddr3_dq_drv);
+ ret |= of_property_read_u32(np, "phy_lpddr3_odt",
+ &timing->phy_lpddr3_odt);
+ ret |= of_property_read_u32(np, "lpddr4_odt_dis_freq",
+ &timing->lpddr4_odt_dis_freq);
+ ret |= of_property_read_u32(np, "lpddr4_drv",
+ &timing->lpddr4_drv);
+ ret |= of_property_read_u32(np, "lpddr4_dq_odt",
+ &timing->lpddr4_dq_odt);
+ ret |= of_property_read_u32(np, "lpddr4_ca_odt",
+ &timing->lpddr4_ca_odt);
+ ret |= of_property_read_u32(np, "phy_lpddr4_ca_drv",
+ &timing->phy_lpddr4_ca_drv);
+ ret |= of_property_read_u32(np, "phy_lpddr4_ck_cs_drv",
+ &timing->phy_lpddr4_ck_cs_drv);
+ ret |= of_property_read_u32(np, "phy_lpddr4_dq_drv",
+ &timing->phy_lpddr4_dq_drv);
+ ret |= of_property_read_u32(np, "phy_lpddr4_odt",
+ &timing->phy_lpddr4_odt);
+
+ return ret;
+}
+
+static struct dram_timing *of_get_ddr_timings(struct device *dev,
+ struct device_node *np)
+{
+ struct dram_timing *timing = NULL;
+ struct device_node *np_tim;
+
+ np_tim = of_parse_phandle(np, "ddr_timing", 0);
+ if (np_tim) {
+ timing = devm_kzalloc(dev, sizeof(*timing), GFP_KERNEL);
+ if (!timing)
+ goto err;
+ if (of_do_get_timing(np_tim, timing)) {
+ devm_kfree(dev, timing);
+ goto err;
+ }
+ return timing;
+ }
+
+err:
+ if (timing) {
+ devm_kfree(dev, timing);
+ timing = NULL;
+ }
+
+ return timing;
+}
+
+static int rk3399_dmcfreq_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rk3399_dmcfreq *data;
+ int ret, irq, index;
+ uint64_t param = 0;
+ uint32_t *timing;
+ 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->rate = clk_get_rate(data->dmc_clk);
+ rk3399_devfreq_dmc_profile.initial_freq = data->rate;
+ 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);
+ 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;
+ }
+
+ /* get dram timing and pass it to bl31 */
+ data->timing = of_get_ddr_timings(dev, np);
+ if (data->timing) {
+ timing = (uint32_t *)data->timing;
+ for (index = 0; index < (sizeof(struct dram_timing) / 4);
+ index++) {
+ param = index;
+ param = param << 32 | *timing++;
+ sip_smc_set_ddr_param(param);
+ param = 0;
+ }
+ }
+ sip_smc_ddr_init();
+
+ init_waitqueue_head(&data->wait_dcf_queue);
+ data->wait_dcf_flag = 0;
+
+ 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");
diff --git a/drivers/devfreq/rockchip/rockchip_dmc.c b/drivers/devfreq/rockchip/rockchip_dmc.c
new file mode 100644
index 0000000..78baee5
--- /dev/null
+++ b/drivers/devfreq/rockchip/rockchip_dmc.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
+ * Author: Lin Huang <hl@xxxxxxxxxxxxxx>
+ * Base on: https://chromium-review.googlesource.com/#/c/231477/
+ *
+ * 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/mutex.h>
+#include <soc/rockchip/rockchip_dmc.h>
+
+static int num_wait;
+static int num_disable;
+static BLOCKING_NOTIFIER_HEAD(dmc_notifier_list);
+static DEFINE_MUTEX(dmc_en_lock);
+static DEFINE_MUTEX(dmc_sync_lock);
+
+/**
+ * rockchip_dmc_enabled - Returns true if dmc freq is enabled, false otherwise.
+ */
+bool rockchip_dmc_enabled(void)
+{
+ return num_disable <= 0 && num_wait <= 1;
+}
+
+/**
+ * rockchip_dmc_enable - Enable dmc frequency scaling. Will only enable
+ * frequency scaling if there are 1 or fewer notifiers. Call to undo
+ * rockchip_dmc_disable.
+ */
+void rockchip_dmc_enable(void)
+{
+ mutex_lock(&dmc_en_lock);
+ num_disable--;
+ WARN_ON(num_disable < 0);
+ if (rockchip_dmc_enabled())
+ dmc_event(DMC_ENABLE);
+ mutex_unlock(&dmc_en_lock);
+}
+
+/**
+ * rockchip_dmc_disable - Disable dmc frequency scaling. Call when something
+ * cannot coincide with dmc frequency scaling.
+ */
+void rockchip_dmc_disable(void)
+{
+ mutex_lock(&dmc_en_lock);
+ if (rockchip_dmc_enabled())
+ dmc_event(DMC_DISABLE);
+ num_disable++;
+ mutex_unlock(&dmc_en_lock);
+}
+
+void dmc_event(int event)
+{
+ mutex_lock(&dmc_sync_lock);
+ blocking_notifier_call_chain(&dmc_notifier_list, event, NULL);
+ mutex_unlock(&dmc_sync_lock);
+}
+
+/**
+ * dmc_register_notifier - register a driver to dmc chain
+ * @nb: notifier function to register
+ */
+int dmc_register_notifier(struct notifier_block *nb)
+{
+ int ret;
+
+ if (!nb)
+ return -EINVAL;
+
+ ret = blocking_notifier_chain_register(&dmc_notifier_list, nb);
+
+ return ret;
+}
+
+/**
+ * dmc_unregister_notifier - unregister a driver from dmc chain
+ * @nb: remove notifier function
+ */
+int dmc_unregister_notifier(struct notifier_block *nb)
+{
+ int ret;
+
+ if (!nb)
+ return -EINVAL;
+
+ ret = blocking_notifier_chain_unregister(&dmc_notifier_list, nb);
+
+ return ret;
+}
+
+/**
+ * rockchip_dmc_get - Register the notifier block for the dmc chain.
+ * @nb The dmc notifier block to register
+ */
+int rockchip_dmc_get(struct notifier_block *nb)
+{
+ if (!nb)
+ return -EINVAL;
+
+ mutex_lock(&dmc_en_lock);
+
+ /*
+ * if have two notifier(enable two vop etc),
+ * need to disable dmc
+ */
+ if (num_wait == 1 && num_disable <= 0)
+ dmc_event(DMC_DISABLE);
+ num_wait++;
+ dmc_register_notifier(nb);
+ mutex_unlock(&dmc_en_lock);
+
+ return 0;
+}
+
+/**
+ * rockchip_dmc_put - Remove the notifier block from the dmc chain.
+ * @nb The dmc notifier block to unregister
+ */
+int rockchip_dmc_put(struct notifier_block *nb)
+{
+ if (!nb)
+ return -EINVAL;
+
+ mutex_lock(&dmc_en_lock);
+ num_wait--;
+
+ /* if notifier from 2 back to 1, enable dmc again */
+ if (num_wait == 1 && num_disable <= 0)
+ dmc_event(DMC_ENABLE);
+ dmc_unregister_notifier(nb);
+ mutex_unlock(&dmc_en_lock);
+
+ return 0;
+}
diff --git a/include/soc/rockchip/rockchip_dmc.h b/include/soc/rockchip/rockchip_dmc.h
new file mode 100644
index 0000000..3f69cbf
--- /dev/null
+++ b/include/soc/rockchip/rockchip_dmc.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * 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.
+ */
+
+#ifndef __SOC_ROCKCHIP_DMC_H
+#define __SOC_ROCKCHIP_DMC_H
+
+#include <linux/notifier.h>
+
+#define DMC_ENABLE 0
+#define DMC_DISABLE 1
+#define DMCFREQ_ADJUST 2
+#define DMCFREQ_FINISH 3
+
+#if IS_ENABLED(CONFIG_ARM_ROCKCHIP_DMC_DEVFREQ)
+int rockchip_dmc_get(struct notifier_block *nb);
+int rockchip_dmc_put(struct notifier_block *nb);
+#else
+static inline int rockchip_dmc_get(struct notifier_block *nb)
+{
+ return 0;
+}
+
+static inline int rockchip_dmc_put(struct notifier_block *nb)
+{
+ return 0;
+}
+#endif
+
+void dmc_event(int event);
+int dmc_register_notifier(struct notifier_block *nb);
+int dmc_unregister_notifier(struct notifier_block *nb);
+void rockchip_dmc_enable(void);
+void rockchip_dmc_disable(void);
+bool rockchip_dmc_enabled(void);
+#endif
Regards,
Chanwoo Choi
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--
Lin Huang