Re: [RFC PATCHv2 4/7] devfreq: event: Add exynos-ppmu devfreq event driver

Chanwoo Choi
2014-12-11T02:20:39Z

Hi Krzysztof,

On 12/10/2014 06:59 PM, Krzysztof Kozlowski wrote:
> On wto, 2014-12-09 at 23:13 +0900, Chanwoo Choi wrote:
>> This patch add exynos-ppmu devfreq event driver to provider raw data about
>> the utilization of each IP in Exynos SoC series.
>>
>> Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
>> Cc: Kyungmin Park <kyungmin.park@samsung.com>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>> ---
>> drivers/devfreq/Kconfig | 9 +
>> drivers/devfreq/event/Makefile | 1 +
>> drivers/devfreq/event/exynos-ppmu.c | 409 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 419 insertions(+)
>> create mode 100644 drivers/devfreq/event/exynos-ppmu.c
>
> I would rather see this as an incremental change for existing
> exynos_ppmu.c file. However I do not insists on that.
>
>>
>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
>> index 4d15b62..d4559f7 100644
>> --- a/drivers/devfreq/Kconfig
>> +++ b/drivers/devfreq/Kconfig
>> @@ -89,4 +89,13 @@ config ARM_EXYNOS5_BUS_DEVFREQ
>>
>> comment "DEVFREQ Event Drivers"
>>
>> +config DEVFREQ_EVENT_EXYNOS_PPMU
>> + bool "EXYNOS PPMU (Performance Profiling Monitoring Unit) DEVFREQ event Driver"
>> + depends on ARCH_EXYNOS
>> + select PM_OPP
>> + help
>> + This add the DEVFREQ event driver for Exynos SoC. It provides PPMU
>> + (Performance Profiling Monitoring Unit) counters to estimate the
>> + utilization of each module.
>> +
>> endif # PM_DEVFREQ
>> diff --git a/drivers/devfreq/event/Makefile b/drivers/devfreq/event/Makefile
>> index dc56005..be146ea 100644
>> --- a/drivers/devfreq/event/Makefile
>> +++ b/drivers/devfreq/event/Makefile
>> @@ -1 +1,2 @@
>> # Exynos DEVFREQ Event Drivers
>> +obj-$(CONFIG_DEVFREQ_EVENT_EXYNOS_PPMU) += exynos-ppmu.o
>> diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c
>> new file mode 100644
>> index 0000000..2706f23
>> --- /dev/null
>> +++ b/drivers/devfreq/event/exynos-ppmu.c
>> @@ -0,0 +1,409 @@
>> +/*
>> + * exynos_ppmu.c - EXYNOS PPMU (Performance Profiling Monitoring Units) support
>> + *
>> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
>> + * Author : Chanwoo Choi <cw00.choi@samsung.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This driver is based on drivers/devfreq/exynos/exynos_ppmu.c
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/suspend.h>
>> +#include <linux/devfreq.h>
>> +
>> +#define PPMU_ENABLE BIT(0)
>> +#define PPMU_DISABLE 0x0
>> +#define PPMU_CYCLE_RESET BIT(1)
>> +#define PPMU_COUNTER_RESET BIT(2)
>> +
>> +#define PPMU_ENABLE_COUNT0 BIT(0)
>> +#define PPMU_ENABLE_COUNT1 BIT(1)
>> +#define PPMU_ENABLE_COUNT2 BIT(2)
>> +#define PPMU_ENABLE_COUNT3 BIT(3)
>> +#define PPMU_ENABLE_CYCLE BIT(31)
>> +
>> +#define PPMU_CNTENS 0x10
>> +#define PPMU_FLAG 0x50
>> +#define PPMU_CCNT_OVERFLOW BIT(31)
>> +#define PPMU_CCNT 0x100
>> +
>> +#define PPMU_PMCNT0 0x110
>> +#define PPMU_PMCNT_OFFSET 0x10
>> +#define PMCNT_OFFSET(x) (PPMU_PMCNT0 + (PPMU_PMCNT_OFFSET * x))
>> +
>> +#define PPMU_BEVT0SEL 0x1000
>> +#define PPMU_BEVTSEL_OFFSET 0x100
>> +#define PPMU_BEVTSEL(x) (PPMU_BEVT0SEL + (x * PPMU_BEVTSEL_OFFSET))
>> +
>> +#define RD_DATA_COUNT 0x5
>> +#define WR_DATA_COUNT 0x6
>> +#define RDWR_DATA_COUNT 0x7
>> +
>> +enum ppmu_counter {
>> + PPMU_PMNCNT0,
>> + PPMU_PMNCNT1,
>> + PPMU_PMNCNT2,
>> + PPMU_PMNCNT3,
>> + PPMU_PMNCNT_MAX,
>> +};
>> +
>> +/* Platform data */
>> +struct exynos_ppmu_data {
>> + struct devfreq *devfreq;
>
> Looks like not used here.

Right. I'll remove it.

>
>> + struct devfreq_event_dev **event_dev;
>> + struct devfreq_event_desc *desc;
>> + unsigned int num_events;
>> +
>> + struct device *dev;
>> + struct clk *clk_ppmu;
>> + struct mutex lock;
>> +
>> + struct __exynos_ppmu {
>> + void __iomem *hw_base;
>> + unsigned int ccnt;
>> + unsigned int event[PPMU_PMNCNT_MAX];
>> + unsigned int count[PPMU_PMNCNT_MAX];
>> + unsigned long long ns;
>> + ktime_t reset_time;
>> + bool ccnt_overflow;
>> + bool count_overflow[PPMU_PMNCNT_MAX];
>> + } ppmu;
>> +};
>> +
>> +struct __exynos_ppmu_events {
>> + char *name;
>> + int id;
>> +} ppmu_events[] = {
>> + { "ppmu-dmc0-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-dmc0-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-dmc0-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-dmc0-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-dmc1-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-dmc1-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-dmc1-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-dmc1-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-cpu-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-cpu-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-cpu-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-cpu-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-rightbus-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-rightbus-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-rightbus-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-rightbus-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-leftbus-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-leftbus-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-leftbus-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-leftbus-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-camif-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-camif-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-camif-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-camif-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-lcd0-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-lcd0-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-lcd0-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-lcd0-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-g3d-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-g3d-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-g3d-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-g3d-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-mfc-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-mfc-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-mfc-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-mfc-pmcnt3", PPMU_PMNCNT3 },
>> +
>> + { "ppmu-fsys-pmcnt0", PPMU_PMNCNT0 },
>> + { "ppmu-fsys-pmcnt1", PPMU_PMNCNT1 },
>> + { "ppmu-fsys-pmcnt2", PPMU_PMNCNT2 },
>> + { "ppmu-fsys-pmcnt3", PPMU_PMNCNT3 },
>> + { /* sentinel */ },
>> +};
>> +
>> +static int exynos_ppmu_enable(struct devfreq_event_dev *event_dev)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu = event_dev_get_drvdata(event_dev);
>> +
>> + __raw_writel(PPMU_ENABLE, exynos_ppmu->ppmu.hw_base);
>> +
>> + return 0;
>> +}
>> +
>> +static int exynos_ppmu_disable(struct devfreq_event_dev *event_dev)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu = event_dev_get_drvdata(event_dev);
>> +
>> + __raw_writel(PPMU_DISABLE, exynos_ppmu->ppmu.hw_base);
>> +
>> + return 0;
>> +}
>> +
>> +static bool exynos_ppmu_is_enabled(struct devfreq_event_dev *event_dev)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu = event_dev_get_drvdata(event_dev);
>> + int val;
>> +
>> + val = __raw_readl(exynos_ppmu->ppmu.hw_base);
>> + if (val & PPMU_ENABLE)
>> + return true;
>> +
>> + return false;
>> +}
>> +
>> +static int exynos_ppmu_find_ppmu_id(struct devfreq_event_dev *event_dev)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(ppmu_events); i++)
>> + if (!strcmp(event_dev->desc->name, ppmu_events[i].name))
>> + return ppmu_events[i].id;
>> +
>> + return -EINVAL;
>> +}
>> +
>> +static int exynos_ppmu_set_event(struct devfreq_event_dev *event_dev,
>> + enum devfreq_event_type event_type)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu = event_dev_get_drvdata(event_dev);
>> + void __iomem *ppmu_base = exynos_ppmu->ppmu.hw_base;
>> + int id = exynos_ppmu_find_ppmu_id(event_dev);
>> +
>> + __raw_writel(RDWR_DATA_COUNT, ppmu_base + PPMU_BEVTSEL(id));
>> +
>> + return 0;
>> +}
>> +
>> +static int exynos_ppmu_get_event(struct devfreq_event_dev *event_dev,
>> + enum devfreq_event_type event_type,
>> + int *total_event)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu = event_dev_get_drvdata(event_dev);
>> + void __iomem *ppmu_base = exynos_ppmu->ppmu.hw_base;
>> + int id = exynos_ppmu_find_ppmu_id(event_dev);
>> + int cnt, total_cnt;
>> +
>> + total_cnt = __raw_readl(ppmu_base + PPMU_CCNT);
>> +
>> + if (id == PPMU_PMNCNT3)
>> + cnt = ((__raw_readl(ppmu_base + PMCNT_OFFSET(id)) << 8) |
>> + __raw_readl(ppmu_base + PMCNT_OFFSET(id + 1)));
>> + else
>> + cnt = __raw_readl(ppmu_base + PMCNT_OFFSET(id));
>> +
>> + *total_event = total_cnt;
>> +
>> + return cnt;
>> +}
>> +
>> +static int exynos_ppmu_reset(struct devfreq_event_dev *event_dev)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu = event_dev_get_drvdata(event_dev);
>> + void __iomem *ppmu_base = exynos_ppmu->ppmu.hw_base;
>> +
>> + __raw_writel(PPMU_CYCLE_RESET | PPMU_COUNTER_RESET, ppmu_base);
>> + __raw_writel(PPMU_ENABLE_CYCLE |
>> + PPMU_ENABLE_COUNT0 |
>> + PPMU_ENABLE_COUNT1 |
>> + PPMU_ENABLE_COUNT2 |
>> + PPMU_ENABLE_COUNT3,
>> + ppmu_base + PPMU_CNTENS);
>> + __raw_writel(PPMU_ENABLE, exynos_ppmu->ppmu.hw_base);
>> +
>> + return 0;
>> +}
>> +
>> +static struct devfreq_event_ops exynos_ppmu_ops = {
>> + .enable = exynos_ppmu_enable,
>> + .disable = exynos_ppmu_disable,
>> + .is_enabled = exynos_ppmu_is_enabled,
>> + .set_event = exynos_ppmu_set_event,
>> + .get_event = exynos_ppmu_get_event,
>> + .reset = exynos_ppmu_reset,
>> +};
>> +
>> +static int of_get_devfreq_events(struct device_node *np,
>> + struct exynos_ppmu_data *exynos_ppmu)
>> +{
>> + struct devfreq_event_desc *desc;
>> + struct device *dev = exynos_ppmu->dev;
>> + struct device_node *events_np, *node;
>> + int i, j, count;
>> +
>> + events_np = of_find_node_by_name(np, "events");
>
> of_get_child_by_name()

OK. I'll use of_get_chilc_by_name() function to get phandle of devfreq-event device in dts.

>
>> + if (!events_np) {
>> + dev_err(dev, "Failed to find ppmus sub-node\n");
>> + return -EINVAL;
>> + }
>> +
>> + count = of_get_child_count(events_np);
>> + desc = devm_kzalloc(dev, sizeof(struct devfreq_event_desc) * count,
>> + GFP_KERNEL);
>> + if (!desc)
>> + return -ENOMEM;
>> + exynos_ppmu->num_events = count;
>> +
>> + j = 0;
>> + for_each_child_of_node(events_np, node) {
>> + for (i = 0; i < ARRAY_SIZE(ppmu_events); i++) {
>> + if (!of_node_cmp(node->name, ppmu_events[i].name))
>> + break;
>> + }
>> +
>> + if (i == ARRAY_SIZE(ppmu_events)) {
>> + dev_warn(dev,
>> + "don't know how to configure events : %s\n",
>> + node->name);
>> + continue;
>> + }
>> + desc[j].ops = &exynos_ppmu_ops;
>> + desc[j].driver_data = exynos_ppmu;
>> + desc[j].event_type |= DEVFREQ_EVENT_TYPE_RAW_DATA;
>> + of_property_read_string(node, "event-name", &desc[j].name);
>> + j++;
>> + }
>> + exynos_ppmu->desc = desc;
>
> of_node_put() for 'events_np' and 'node' in loop.

OK, I'll add it.

>
>> +
>> + return 0;
>> +}
>> +
>> +static int exynos_ppmu_parse_dt(struct exynos_ppmu_data *exynos_ppmu)
>> +{
>> + struct device *dev = exynos_ppmu->dev;
>> + struct device_node *np = dev->of_node;
>> + int ret = 0;
>> +
>> + if (!np) {
>> + dev_err(dev, "Failed to find devicetree node\n");
>> + return -EINVAL;
>> + }
>> +
>> + /* Maps the memory mapped IO to control PPMU register */
>> + exynos_ppmu->ppmu.hw_base = of_iomap(np, 0);
>> + if (IS_ERR_OR_NULL(exynos_ppmu->ppmu.hw_base)) {
>> + dev_err(dev, "Failed to map memory region\n");
>> + ret = -EINVAL;
>> + goto err_iomap;
>> + }
>> +
>> + /* FIXME: Get the clock of ppmu and enable this clock */
>> + exynos_ppmu->clk_ppmu = devm_clk_get(dev, "ppmu");
>> + if (IS_ERR(exynos_ppmu->clk_ppmu))
>> + dev_warn(dev, "Failed to get PPMU clock\n");
>> +
>> + ret = of_get_devfreq_events(np, exynos_ppmu);
>> + if (ret < 0) {
>> + dev_err(dev, "Failed to parse exynos ppmu dt node\n");
>> + goto err_clock;
>> + }
>> +
>> + return 0;
>> +
>> +err_clock:
>> + clk_disable_unprepare(exynos_ppmu->clk_ppmu);
>
> Not needed. Clock is not enabled here.

OK. I'll fix it.

>
>> +err_iomap:
>> + iounmap(exynos_ppmu->ppmu.hw_base);
>> +
>> + return ret;
>> +}
>> +
>> +static int exynos_ppmu_probe(struct platform_device *pdev)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu;
>> + struct devfreq_event_dev **event_dev;
>> + struct devfreq_event_desc *desc;
>> + int i, ret = 0, size;
>> +
>> + /* Allocate the memory of exynos_ppmu_data and initialize it */
>> + exynos_ppmu = devm_kzalloc(&pdev->dev, sizeof(struct exynos_ppmu_data),
>> + GFP_KERNEL);
>> + if (!exynos_ppmu)
>> + return -ENOMEM;
>> +
>> + mutex_init(&exynos_ppmu->lock);
>> + exynos_ppmu->dev = &pdev->dev;
>> +
>> + /* Parse dt data to get resource */
>> + ret = exynos_ppmu_parse_dt(exynos_ppmu);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "Failed to parse DT node for resource\n");
>> + return ret;
>> + }
>> + desc = exynos_ppmu->desc;
>> +
>> + size = sizeof(struct devfreq_event_dev *) * exynos_ppmu->num_events;
>> + exynos_ppmu->event_dev = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
>> + if (!exynos_ppmu->event_dev) {
>> + dev_err(&pdev->dev,
>> + "Failed to allocate memory devfreq_event_dev list\n");
>> + return -ENOMEM;
>> + }
>> + event_dev = exynos_ppmu->event_dev;
>> + platform_set_drvdata(pdev, exynos_ppmu);
>
> Missing clk_prepare_enable().

OK, I'll add it.

>
>> +
>> + for (i = 0; i < exynos_ppmu->num_events; i++) {
>> + event_dev[i] = devfreq_add_event_device(&pdev->dev, &desc[i]);
>> + if (IS_ERR(event_dev)) {
>> + ret = PTR_ERR(event_dev);
>> + dev_err(&pdev->dev, "Failed to add devfreq evt dev\n");
>> + goto err;
>> + }
>> + }
>> +
>> + return 0;
>> +err:
>> + clk_disable_unprepare(exynos_ppmu->clk_ppmu);
>> + iounmap(exynos_ppmu->ppmu.hw_base);
>> +
>> + return ret;
>> +}
>> +
>> +static int exynos_ppmu_remove(struct platform_device *pdev)
>> +{
>> + struct exynos_ppmu_data *exynos_ppmu = platform_get_drvdata(pdev);
>> +
>> + clk_disable_unprepare(exynos_ppmu->clk_ppmu);
>> + iounmap(exynos_ppmu->ppmu.hw_base);
>> +
>> + /* Remove devfreq instance */
>> + devfreq_remove_device(exynos_ppmu->devfreq);
>
> Shouldn't this be devfreq_remove_event_dev()?

Your right. It is my mistake. I'll fix it.

Thanks for your review.

Best Regards,
Chanwoo Choi