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

From: [email-masked] (hl)
Date: Tue, 26 Jul 2016 09:15:10 +0800

Hi Chanwoo Choi,

On 2016?07?25? 17:45, Chanwoo Choi wrote:
> Hi Lin,
>
> On 2016? 07? 25? 17:47, hl wrote:
>> 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?
> Firstly,
> The devfreq has the devfreq_get_devfreq_by_phandle() function
> to get the devfreq pointer in device tree. The vop_bind()
> get the IORESOURCE_MEM and interrupt. So, I think that you
> would get the devfreq pointer in the vop_bind() function.
> So, DEVFREQ_TRANSITION_NOTIFIER can alter the following two notifications:
> - dmc_event(DMCFREQ_ADJUST);
> - dmc_event(DMCFREQ_FINISH);
>
>
> Also,
> devfreq-event fwk provide the devfreq_event_get_edev_by_phandle() funtcion
> to get the devfreq-event pointer in the device tree.
>
> You could call the devfreq_event_[enable/disable[_edev()
> and devfreq_[resume/suspend]_device in the drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> instead of dmc_event(DMC_ENABLE) / dmc_event(DMC_DISABLE).
>
> dmc_event(DMC_ENABLE);
> 	devfreq_event_enable_edev(dmcfreq->edev);
> 	devfreq_resume_device(dmcfreq->devfreq);
>
> dmc_event(DMC_DISABLE);
> 	devfreq_event_disable_edev(dmcfreq->edev);
> 	devfreq_suspend_device(dmcfreq->devfreq);
>
> I think that we have to use the standard interfaces and
> functions providing by framework. It is not appropriate way
> to define the specific functions for only one device driver
> between other framework.

Thanks for you suggestion, this may be a huge update, i will try to 
implement it.
>
> Regards,
> Chanwoo Choi
>
>>>> +    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