Re: [PATCH v4 5/7] PM / devfreq: event: support rockchip dfi controller

[Chanwoo Choi]

Hi Lin,

I add the one minor comment for full name of 'DRI'.

On 2016ë 08ì 01ì 16:41, Chanwoo Choi wrote:
> Hi Lin,
> 
> Because you remove the 'RFC' prefix on patch title,
> I think that you better to make the documentation as following: 
> - Documentation/devicetree/bindings/devfreq/event/rockchip-dfi.txt
> 
> Regards,
> Chanwoo Choi
> 
> On 2016ë 07ì 29ì 16:56, Lin Huang wrote:
>> on rk3399 platform, there is dfi conroller can monitor
>> ddr load, base on this result, we can do ddr freqency
>> scaling.
>>
>> Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx>
>> Acked-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
>> ---
>> Changes in v4:
>> - None
>>
>> Changes in v3:
>> - None
>>
>> Changes in v2:
>> - use clk_disable_unprepare and clk_enable_prepare
>> - remove clk_enable_prepare in probe
>> - remove rockchip_dfi_remove function
>>
>> Changes in v1:
>> - None
>>
>>  drivers/devfreq/event/Kconfig        |   7 +
>>  drivers/devfreq/event/Makefile       |   1 +
>>  drivers/devfreq/event/rockchip-dfi.c | 253 +++++++++++++++++++++++++++++++++++
>>  3 files changed, 261 insertions(+)
>>  create mode 100644 drivers/devfreq/event/rockchip-dfi.c
>>
>> diff --git a/drivers/devfreq/event/Kconfig b/drivers/devfreq/event/Kconfig
>> index a11720a..ff9279f 100644
>> --- a/drivers/devfreq/event/Kconfig
>> +++ b/drivers/devfreq/event/Kconfig
>> @@ -22,4 +22,11 @@ config DEVFREQ_EVENT_EXYNOS_PPMU
>>  	  (Platform Performance Monitoring Unit) counters to estimate the
>>  	  utilization of each module.
>>  
>> +config DEVFREQ_EVENT_ROCKCHIP_DFI
>> +	tristate "ROCKCHIP DFI DEVFREQ event Driver"
>> +	depends on ARCH_ROCKCHIP
>> +	help
>> +	  This add the devfreq-event driver for Rockchip SoC. It provides DFI
>> +	  (DDR Monitor Module) driver to count ddr load.

The DFI is "DDR Monitor Module" full name? I need the correct abbreviation 
and full name.

>> +
>>  endif # PM_DEVFREQ_EVENT
>> diff --git a/drivers/devfreq/event/Makefile b/drivers/devfreq/event/Makefile
>> index be146ea..e3f88fc 100644
>> --- a/drivers/devfreq/event/Makefile
>> +++ b/drivers/devfreq/event/Makefile
>> @@ -1,2 +1,3 @@
>>  # Exynos DEVFREQ Event Drivers
>>  obj-$(CONFIG_DEVFREQ_EVENT_EXYNOS_PPMU) += exynos-ppmu.o
>> +obj-$(CONFIG_DEVFREQ_EVENT_ROCKCHIP_DFI) += rockchip-dfi.o
>> diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c
>> new file mode 100644
>> index 0000000..96a0307
>> --- /dev/null
>> +++ b/drivers/devfreq/event/rockchip-dfi.c
>> @@ -0,0 +1,253 @@
>> +/*
>> + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
>> + * Author: Lin Huang <hl@xxxxxxxxxxxxxx>
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>> + * more details.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/devfreq-event.h>
>> +#include <linux/kernel.h>
>> +#include <linux/err.h>
>> +#include <linux/init.h>
>> +#include <linux/io.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +#include <linux/list.h>
>> +#include <linux/of.h>
>> +
>> +#define RK3399_DMC_NUM_CH	2
>> +
>> +/* DDRMON_CTRL */
>> +#define DDRMON_CTRL	0x04
>> +#define CLR_DDRMON_CTRL	(0x1f0000 << 0)
>> +#define LPDDR4_EN	(0x10001 << 4)
>> +#define HARDWARE_EN	(0x10001 << 3)
>> +#define LPDDR3_EN	(0x10001 << 2)
>> +#define SOFTWARE_EN	(0x10001 << 1)
>> +#define TIME_CNT_EN	(0x10001 << 0)
>> +
>> +#define DDRMON_CH0_COUNT_NUM		0x28
>> +#define DDRMON_CH0_DFI_ACCESS_NUM	0x2c
>> +#define DDRMON_CH1_COUNT_NUM		0x3c
>> +#define DDRMON_CH1_DFI_ACCESS_NUM	0x40
>> +
>> +/* pmu grf */
>> +#define PMUGRF_OS_REG2	0x308
>> +#define DDRTYPE_SHIFT	13
>> +#define DDRTYPE_MASK	7
>> +
>> +enum {
>> +	DDR3 = 3,
>> +	LPDDR3 = 6,
>> +	LPDDR4 = 7,
>> +	UNUSED = 0xFF
>> +};
>> +
>> +struct dmc_usage {
>> +	u32 access;
>> +	u32 total;
>> +};
>> +
>> +struct rockchip_dfi {
>> +	struct devfreq_event_dev *edev;
>> +	struct devfreq_event_desc *desc;
>> +	struct dmc_usage ch_usage[RK3399_DMC_NUM_CH];
>> +	struct device *dev;
>> +	void __iomem *regs;
>> +	struct regmap *regmap_pmu;
>> +	struct clk *clk;
>> +};
>> +
>> +static void rockchip_dfi_start_hardware_counter(struct devfreq_event_dev *edev)
>> +{
>> +	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
>> +	void __iomem *dfi_regs = info->regs;
>> +	u32 val;
>> +	u32 ddr_type;
>> +
>> +	/* get ddr type */
>> +	regmap_read(info->regmap_pmu, PMUGRF_OS_REG2, &val);
>> +	ddr_type = (val >> DDRTYPE_SHIFT) & DDRTYPE_MASK;
>> +
>> +	/* clear DDRMON_CTRL setting */
>> +	writel_relaxed(CLR_DDRMON_CTRL, dfi_regs + DDRMON_CTRL);
>> +
>> +	/* set ddr type to dfi */
>> +	if (ddr_type == LPDDR3)
>> +		writel_relaxed(LPDDR3_EN, dfi_regs + DDRMON_CTRL);
>> +	else if (ddr_type == LPDDR4)
>> +		writel_relaxed(LPDDR4_EN, dfi_regs + DDRMON_CTRL);
>> +
>> +	/* enable count, use software mode */
>> +	writel_relaxed(SOFTWARE_EN, dfi_regs + DDRMON_CTRL);
>> +}
>> +
>> +static void rockchip_dfi_stop_hardware_counter(struct devfreq_event_dev *edev)
>> +{
>> +	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
>> +	void __iomem *dfi_regs = info->regs;
>> +	u32 val;
>> +
>> +	val = readl_relaxed(dfi_regs + DDRMON_CTRL);
>> +	val &= ~SOFTWARE_EN;
>> +	writel_relaxed(val, dfi_regs + DDRMON_CTRL);
>> +}
>> +
>> +static int rockchip_dfi_get_busier_ch(struct devfreq_event_dev *edev)
>> +{
>> +	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
>> +	u32 tmp, max = 0;
>> +	u32 i, busier_ch = 0;
>> +	void __iomem *dfi_regs = info->regs;
>> +
>> +	rockchip_dfi_stop_hardware_counter(edev);
>> +
>> +	/* Find out which channel is busier */
>> +	for (i = 0; i < RK3399_DMC_NUM_CH; i++) {
>> +		info->ch_usage[i].access = readl_relaxed(dfi_regs +
>> +				DDRMON_CH0_DFI_ACCESS_NUM + i * 20);
>> +		info->ch_usage[i].total = readl_relaxed(dfi_regs +
>> +				DDRMON_CH0_COUNT_NUM + i * 20);
>> +		tmp = info->ch_usage[i].access;
>> +		if (tmp > max) {
>> +			busier_ch = i;
>> +			max = tmp;
>> +		}
>> +	}
>> +	rockchip_dfi_start_hardware_counter(edev);
>> +
>> +	return busier_ch;
>> +}
>> +
>> +static int rockchip_dfi_disable(struct devfreq_event_dev *edev)
>> +{
>> +	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
>> +
>> +	rockchip_dfi_stop_hardware_counter(edev);
>> +	clk_disable_unprepare(info->clk);
>> +
>> +	return 0;
>> +}
>> +
>> +static int rockchip_dfi_enable(struct devfreq_event_dev *edev)
>> +{
>> +	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
>> +	int ret;
>> +
>> +	ret = clk_prepare_enable(info->clk);
>> +	if (ret) {
>> +		dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	rockchip_dfi_start_hardware_counter(edev);
>> +	return 0;
>> +}
>> +
>> +static int rockchip_dfi_set_event(struct devfreq_event_dev *edev)
>> +{
>> +	return 0;
>> +}
>> +
>> +static int rockchip_dfi_get_event(struct devfreq_event_dev *edev,
>> +				  struct devfreq_event_data *edata)
>> +{
>> +	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
>> +	int busier_ch;
>> +
>> +	busier_ch = rockchip_dfi_get_busier_ch(edev);
>> +
>> +	edata->load_count = info->ch_usage[busier_ch].access;
>> +	edata->total_count = info->ch_usage[busier_ch].total;
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct devfreq_event_ops rockchip_dfi_ops = {
>> +	.disable = rockchip_dfi_disable,
>> +	.enable = rockchip_dfi_enable,
>> +	.get_event = rockchip_dfi_get_event,
>> +	.set_event = rockchip_dfi_set_event,
>> +};
>> +
>> +static const struct of_device_id rockchip_dfi_id_match[] = {
>> +	{ .compatible = "rockchip,rk3399-dfi" },
>> +	{ },
>> +};
>> +
>> +static int rockchip_dfi_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct rockchip_dfi *data;
>> +	struct resource *res;
>> +	struct devfreq_event_desc *desc;
>> +	struct device_node *np = pdev->dev.of_node, *node;
>> +
>> +	data = devm_kzalloc(dev, sizeof(struct rockchip_dfi), GFP_KERNEL);
>> +	if (!data)
>> +		return -ENOMEM;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	data->regs = devm_ioremap_resource(&pdev->dev, res);
>> +	if (IS_ERR(data->regs))
>> +		return PTR_ERR(data->regs);
>> +
>> +	data->clk = devm_clk_get(dev, "pclk_ddr_mon");
>> +	if (IS_ERR(data->clk)) {
>> +		dev_err(dev, "Cannot get the clk dmc_clk\n");
>> +		return PTR_ERR(data->clk);
>> +	};
>> +
>> +	/* try to find the optional reference to the pmu syscon */
>> +	node = of_parse_phandle(np, "rockchip,pmu", 0);
>> +	if (node) {
>> +		data->regmap_pmu = syscon_node_to_regmap(node);
>> +		if (IS_ERR(data->regmap_pmu))
>> +			return PTR_ERR(data->regmap_pmu);
>> +	}
>> +	data->dev = dev;
>> +
>> +	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
>> +	if (!desc)
>> +		return -ENOMEM;
>> +
>> +	desc->ops = &rockchip_dfi_ops;
>> +	desc->driver_data = data;
>> +	desc->name = np->name;
>> +	data->desc = desc;
>> +
>> +	data->edev = devm_devfreq_event_add_edev(&pdev->dev, desc);
>> +	if (IS_ERR(data->edev)) {
>> +		dev_err(&pdev->dev,
>> +			"failed to add devfreq-event device\n");
>> +		return PTR_ERR(data->edev);
>> +	}
>> +
>> +	platform_set_drvdata(pdev, data);
>> +
>> +	return 0;
>> +}
>> +
>> +static struct platform_driver rockchip_dfi_driver = {
>> +	.probe	= rockchip_dfi_probe,
>> +	.driver = {
>> +		.name	= "rockchip-dfi",
>> +		.of_match_table = rockchip_dfi_id_match,
>> +	},
>> +};
>> +module_platform_driver(rockchip_dfi_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR("Lin Huang <hl@xxxxxxxxxxxxxx>");
>> +MODULE_DESCRIPTION("Rockchip dfi driver");

s/dfi -> DFI

Regards,
Chanwoo Choi