Re: [PATCH v7 7/8] PM / devfreq: rockchip: add devfreq driver for rk3399 dmc

Brian Norris
2016-08-26T21:17:04Z

Hi,

On Mon, Aug 22, 2016 at 11:36:23AM +0800, 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@rock-chips.com>
> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
> ---
> Changes in v7:
> - remove a blank line
>
> Changes in v6:
> - fix some nit suggest by Chanwoo Choi
>
> Changes in v5:
> - improve dmc driver suggest by Chanwoo Choi
>
> Changes in v4:
> - use arm_smccc_smc() function talk to bl31
> - delete rockchip_dmc.c file and config
> - delete dmc_notify
> - adjust probe order
>
> 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 | 11 +
> drivers/devfreq/Makefile | 1 +
> drivers/devfreq/rk3399_dmc.c | 499 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 511 insertions(+)
> create mode 100644 drivers/devfreq/rk3399_dmc.c
>
> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
> index a5be56e..e848121 100644
> --- a/drivers/devfreq/Kconfig
> +++ b/drivers/devfreq/Kconfig
> @@ -100,6 +100,17 @@ config ARM_TEGRA_DEVFREQ
> It reads ACTMON counters of memory controllers and adjusts the
> operating frequencies and voltages with OPP support.
>
> +config ARM_RK3399_DMC_DEVFREQ
> + tristate "ARM RK3399 DMC DEVFREQ Driver"
> + depends on ARCH_ROCKCHIP
> + select DEVFREQ_EVENT_ROCKCHIP_DFI
> + select DEVFREQ_GOV_SIMPLE_ONDEMAND
> + select PM_OPP
> + help
> + This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller).
> + It sets the frequency for the memory controller and reads the usage counts
> + from hardware.
> +
> source "drivers/devfreq/event/Kconfig"
>
> endif # PM_DEVFREQ
> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
> index 09f11d9..fbff40a 100644
> --- a/drivers/devfreq/Makefile
> +++ b/drivers/devfreq/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o
>
> # DEVFREQ Drivers
> obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o
> +obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o
> obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o
>
> # DEVFREQ Event Drivers
> diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c
> new file mode 100644
> index 0000000..b73a73c
> --- /dev/null
> +++ b/drivers/devfreq/rk3399_dmc.c
> @@ -0,0 +1,499 @@
> +/*
> + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd.
> + * Author: Lin Huang <hl@rock-chips.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + */
> +
> +#include <linux/arm-smccc.h>
> +#include <linux/clk.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 <soc/rockchip/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 dram_timing *timing;

Are you actually using this after probe time, or are you just loading
this straight into ATF? If the latter, then you can just use a stack
variable, with no kmalloc() (and you *definitely* don't need
devm_kzalloc()!).

> +
> + /*
> + * DDR Converser of Frequency (DCF) is used to implement DDR frequency
> + * conversion without the participation of CPU, we will implement and
> + * control it in arm trust firmware.
> + */
> + 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;
> + struct dev_pm_opp *curr_opp;
> +};
> +
> +static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq,
> + u32 flags)
> +{
> + struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
> + 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);
> +
> + dmcfreq->rate = dev_pm_opp_get_freq(dmcfreq->curr_opp);
> + dmcfreq->volt = dev_pm_opp_get_voltage(dmcfreq->curr_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, adjust frequency first.
> + */
> + if (old_clk_rate < target_rate) {
> + err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
> + target_volt);
> + if (err) {
> + dev_err(dev, "Cannot to set voltage %lu uV\n",
> + target_volt);
> + goto out;
> + }
> + }
> + dmcfreq->wait_dcf_flag = 1;
> +
> + err = clk_set_rate(dmcfreq->dmc_clk, target_rate);
> + if (err) {
> + dev_err(dev, "Cannot to set frequency %lu (%d)\n",
> + target_rate, err);
> + regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
> + dmcfreq->volt);
> + goto out;
> + }
> +
> + /*
> + * Wait until bcf irq happen, it means freq scaling finish in
> + * arm trust firmware, use 100ms as timeout time.
> + */
> + if (!wait_event_timeout(dmcfreq->wait_dcf_queue,
> + !dmcfreq->wait_dcf_flag, HZ / 10))
> + dev_warn(dev, "Timeout waiting for dcf interrupt\n");
> +
> + /*
> + * 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 frequency %lu,\
> + Current frequency %lu\n", target_rate, dmcfreq->rate);
> + regulator_set_voltage(dmcfreq->vdd_center, dmcfreq->volt,
> + dmcfreq->volt);
> + goto out;
> + } else if (old_clk_rate > target_rate)
> + err = regulator_set_voltage(dmcfreq->vdd_center, target_volt,
> + target_volt);
> + if (err)
> + dev_err(dev, "Cannot to set vol %lu uV\n", target_volt);
> +
> + dmcfreq->curr_opp = opp;
> +out:
> + mutex_unlock(&dmcfreq->lock);
> + return err;
> +}
> +
> +static int rk3399_dmcfreq_get_dev_status(struct device *dev,
> + struct devfreq_dev_status *stat)
> +{
> + struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
> + struct devfreq_event_data edata;
> + int ret = 0;
> +
> + ret = devfreq_event_get_event(dmcfreq->edev, &edata);
> + if (ret < 0)
> + return ret;
> +
> + stat->current_frequency = dmcfreq->rate;
> + stat->busy_time = edata.load_count;
> + stat->total_time = edata.total_count;
> +
> + return ret;
> +}
> +
> +static int rk3399_dmcfreq_get_cur_freq(struct device *dev, unsigned long *freq)
> +{
> + struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
> +
> + *freq = dmcfreq->rate;
> +
> + return 0;
> +}
> +
> +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,
> +};
> +
> +static __maybe_unused int rk3399_dmcfreq_suspend(struct device *dev)
> +{
> + struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
> + int ret = 0;
> +
> + ret = devfreq_event_disable_edev(dmcfreq->edev);
> + if (ret < 0) {
> + dev_err(dev, "failed to disable the devfreq-event devices\n");
> + return ret;
> + }
> +
> + ret = devfreq_suspend_device(dmcfreq->devfreq);
> + if (ret < 0) {
> + dev_err(dev, "failed to suspend the devfreq devices\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static __maybe_unused int rk3399_dmcfreq_resume(struct device *dev)
> +{
> + struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
> + int ret = 0;
> +
> + ret = devfreq_event_enable_edev(dmcfreq->edev);
> + if (ret < 0) {
> + dev_err(dev, "failed to enable the devfreq-event devices\n");
> + return ret;
> + }
> +
> + ret = devfreq_resume_device(dmcfreq->devfreq);
> + if (ret < 0) {
> + dev_err(dev, "failed to resume the devfreq devices\n");
> + return ret;
> + }
> + return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(rk3399_dmcfreq_pm, rk3399_dmcfreq_suspend,
> + rk3399_dmcfreq_resume);
> +
> +static irqreturn_t rk3399_dmc_irq(int irq, void *dev_id)
> +{
> + struct rk3399_dmcfreq *dmcfreq = dev_id;
> + struct arm_smccc_res res;
> +
> + dmcfreq->wait_dcf_flag = 0;
> + wake_up(&dmcfreq->wait_dcf_queue);
> +
> + /* Clear the DCF interrupt */
> + arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
> + ROCKCHIP_SIP_CONFIG_DRAM_CLR_IRQ,
> + 0, 0, 0, 0, &res);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static struct dram_timing *of_get_ddr_timings(struct device *dev,
> + struct device_node *np)

You can make 'struct dram_timing *' into an input parameter, and then
just return an int -- 0 for succes, and negative/non-zero for
not-found/error.

> +{
> + struct dram_timing *timing = NULL;
> + struct device_node *np_tim;
> + int ret;
> +
> + np_tim = of_parse_phandle(np, "ddr_timing", 0);
> + if (np_tim) {
> + timing = devm_kzalloc(dev, sizeof(*timing), GFP_KERNEL);

Why devm_*? If you're going to k[zm]alloc() at all, you should just free
it in probe() after you're done with it. Then you don't need devm_* at
all.

> + if (!timing)
> + goto err;
> +
> + ret = of_property_read_u32(np_tim, "ddr3_speed_bin",
> + &timing->ddr3_speed_bin);
> + ret |= of_property_read_u32(np_tim, "pd_idle",
> + &timing->pd_idle);
> + ret |= of_property_read_u32(np_tim, "sr_idle",
> + &timing->sr_idle);
> + ret |= of_property_read_u32(np_tim, "sr_mc_gate_idle",
> + &timing->sr_mc_gate_idle);
> + ret |= of_property_read_u32(np_tim, "srpd_lite_idle",
> + &timing->srpd_lite_idle);
> + ret |= of_property_read_u32(np_tim, "standby_idle",
> + &timing->standby_idle);
> + ret |= of_property_read_u32(np_tim, "dram_dll_dis_freq",
> + &timing->dram_dll_dis_freq);
> + ret |= of_property_read_u32(np_tim, "phy_dll_dis_freq",
> + &timing->phy_dll_dis_freq);
> + ret |= of_property_read_u32(np_tim, "ddr3_odt_dis_freq",
> + &timing->ddr3_odt_dis_freq);
> + ret |= of_property_read_u32(np_tim, "ddr3_drv",
> + &timing->ddr3_drv);
> + ret |= of_property_read_u32(np_tim, "ddr3_odt",
> + &timing->ddr3_odt);
> + ret |= of_property_read_u32(np_tim, "phy_ddr3_ca_drv",
> + &timing->phy_ddr3_ca_drv);
> + ret |= of_property_read_u32(np_tim, "phy_ddr3_dq_drv",
> + &timing->phy_ddr3_dq_drv);
> + ret |= of_property_read_u32(np_tim, "phy_ddr3_odt",
> + &timing->phy_ddr3_odt);
> + ret |= of_property_read_u32(np_tim, "lpddr3_odt_dis_freq",
> + &timing->lpddr3_odt_dis_freq);
> + ret |= of_property_read_u32(np_tim, "lpddr3_drv",
> + &timing->lpddr3_drv);
> + ret |= of_property_read_u32(np_tim, "lpddr3_odt",
> + &timing->lpddr3_odt);
> + ret |= of_property_read_u32(np_tim, "phy_lpddr3_ca_drv",
> + &timing->phy_lpddr3_ca_drv);
> + ret |= of_property_read_u32(np_tim, "phy_lpddr3_dq_drv",
> + &timing->phy_lpddr3_dq_drv);
> + ret |= of_property_read_u32(np_tim, "phy_lpddr3_odt",
> + &timing->phy_lpddr3_odt);
> + ret |= of_property_read_u32(np_tim, "lpddr4_odt_dis_freq",
> + &timing->lpddr4_odt_dis_freq);
> + ret |= of_property_read_u32(np_tim, "lpddr4_drv",
> + &timing->lpddr4_drv);
> + ret |= of_property_read_u32(np_tim, "lpddr4_dq_odt",
> + &timing->lpddr4_dq_odt);
> + ret |= of_property_read_u32(np_tim, "lpddr4_ca_odt",
> + &timing->lpddr4_ca_odt);
> + ret |= of_property_read_u32(np_tim, "phy_lpddr4_ca_drv",
> + &timing->phy_lpddr4_ca_drv);
> + ret |= of_property_read_u32(np_tim, "phy_lpddr4_ck_cs_drv",
> + &timing->phy_lpddr4_ck_cs_drv);
> + ret |= of_property_read_u32(np_tim, "phy_lpddr4_dq_drv",
> + &timing->phy_lpddr4_dq_drv);
> + ret |= of_property_read_u32(np_tim, "phy_lpddr4_odt",
> + &timing->phy_lpddr4_odt);
> + if (ret) {
> + devm_kfree(dev, timing);

This would be kfree() (not devm_kfree()). Or kill it entirely, if you
have the caller just put this on the stack for us.

Brian

> + goto err;
> + }
> + of_node_put(np_tim);
> + return timing;
> + }
> +
> +err:
> + if (timing) {
> + devm_kfree(dev, timing);
> + timing = NULL;
> + }
> + of_node_put(np_tim);
> + return timing;
> +}
> +
> +static int rk3399_dmcfreq_probe(struct platform_device *pdev)
> +{
> + struct arm_smccc_res res;
> + struct device *dev = &pdev->dev;
> + struct device_node *np = pdev->dev.of_node;
> + struct rk3399_dmcfreq *data;
> + int ret, irq, index, size;
> + uint32_t *timing;
> + struct dev_pm_opp *opp;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "Cannot get the dmc interrupt 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->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;
> + }
> +
> + init_waitqueue_head(&data->wait_dcf_queue);
> + data->wait_dcf_flag = 0;
> +
> + 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;
> + }
> +
> + /*
> + * Get dram timing and pass it to arm trust firmware,
> + * the dram drvier in arm trust firmware will get these
> + * timing and to do dram initial.
> + */
> + data->timing = of_get_ddr_timings(dev, np);
> + if (data->timing) {
> + timing = (uint32_t *)data->timing;
> + size = sizeof(struct dram_timing) / 4;
> + for (index = 0; index < size; index++) {
> + arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, *timing++, index,
> + ROCKCHIP_SIP_CONFIG_DRAM_SET_PARAM,
> + 0, 0, 0, 0, &res);
> + if (res.a0) {
> + dev_err(dev, "Failed to set dram param: %ld\n",
> + res.a0);
> + return -EINVAL;
> + }
> + }
> + }
> +
> + arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
> + ROCKCHIP_SIP_CONFIG_DRAM_INIT,
> + 0, 0, 0, 0, &res);
> +
> + /*
> + * 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");
> + rcu_read_unlock();
> + 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);
> +
> + rcu_read_lock();
> + opp = devfreq_recommended_opp(dev, &data->rate, 0);
> + if (IS_ERR(opp)) {
> + rcu_read_unlock();
> + return PTR_ERR(opp);
> + }
> + rcu_read_unlock();
> + data->curr_opp = opp;
> +
> + 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);
> + devm_devfreq_register_opp_notifier(dev, data->devfreq);
> +
> + 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);
> +
> + 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_AUTHOR("Lin Huang <hl@rock-chips.com>");
> +MODULE_DESCRIPTION("RK3399 dmcfreq driver with devfreq framework");
> --
> 2.6.6
>