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

From: [email-masked] (Chanwoo Choi)
Date: Mon, 25 Jul 2016 18:45:52 +0900

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.

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
>