Subject: [PATCH v3 6/7] PM / devfreq: rockchip: add devfreq driver for rk3399 dmc

From: [email-masked] (hl)
Date: Mon, 25 Jul 2016 16:47:18 +0800

Hi Chanwoo Choi,

On 2016?07?25? 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 2016? 07? 22? 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 <[email-masked]>
>> ---
>> 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 <[email-masked]>
>> + *
>> + * 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 <[email-masked]>
>> + * 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
>
>
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip

-- 
Lin Huang