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Date: Thu, 2 May 2019 10:25:36 +0900
From: Chanwoo Choi <cw00.choi@...sung.com>
To: Lukasz Luba <l.luba@...tner.samsung.com>,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-pm@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org
Cc: b.zolnierkie@...sung.com, krzk@...nel.org, robh+dt@...nel.org,
mark.rutland@....com, kyungmin.park@...sung.com,
m.szyprowski@...sung.com, s.nawrocki@...sung.com,
myungjoo.ham@...sung.com, kgene@...nel.org,
willy.mh.wolff.ml@...il.com
Subject: Re: [PATCH v3 2/4] drivers: devfreq: events: extend events by type
of counted data
Hi Lukasz,
On 19. 5. 1. 오전 6:19, Lukasz Luba wrote:
> Hi Chanwoo,
>
> On 4/30/19 9:34 AM, Chanwoo Choi wrote:
>> Hi Lukasz,
>>
>> On 19. 4. 19. 오후 10:48, Lukasz Luba wrote:
>>> This patch adds posibility to choose what type of data should be counted
>>> by the PPMU counter. Now the type comes from DT where the event has been
>>> defined. When there is no 'event-data-type' the default value is used,
>>> which is 'read data in bytes'.
>>> It is needed when you want to know not only read+write data bytes but
>>> i.e. only write data in byte, or number of read requests, etc.
>>>
>>> Signed-off-by: Lukasz Luba <l.luba@...tner.samsung.com>
>>> ---
>>> drivers/devfreq/event/exynos-ppmu.c | 61 +++++++++++++++++++++++++------------
>>> include/linux/devfreq-event.h | 6 ++++
>>> 2 files changed, 48 insertions(+), 19 deletions(-)
>>>
>>> diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c
>>> index c61de0b..073bf2c 100644
>>> --- a/drivers/devfreq/event/exynos-ppmu.c
>>> +++ b/drivers/devfreq/event/exynos-ppmu.c
>>> @@ -154,9 +154,9 @@ static int exynos_ppmu_set_event(struct devfreq_event_dev *edev)
>>> if (ret < 0)
>>> return ret;
>>>
>>> - /* Set the event of Read/Write data count */
>>> + /* Set the event of proper data type monitoring */
>>> ret = regmap_write(info->regmap, PPMU_BEVTxSEL(id),
>>> - PPMU_RO_DATA_CNT | PPMU_WO_DATA_CNT);
>>> + edev->desc->data_type);
>>> if (ret < 0)
>>> return ret;
>>>
>>> @@ -368,23 +368,11 @@ static int exynos_ppmu_v2_set_event(struct devfreq_event_dev *edev)
>>> if (ret < 0)
>>> return ret;
>>>
>>> - /* Set the event of Read/Write data count */
>>> - switch (id) {
>>> - case PPMU_PMNCNT0:
>>> - case PPMU_PMNCNT1:
>>> - case PPMU_PMNCNT2:
>>> - ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
>>> - PPMU_V2_RO_DATA_CNT | PPMU_V2_WO_DATA_CNT);
>>> - if (ret < 0)
>>> - return ret;
>>> - break;
>>> - case PPMU_PMNCNT3:
>>> - ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
>>> - PPMU_V2_EVT3_RW_DATA_CNT);
>>> - if (ret < 0)
>>> - return ret;
>>> - break;
>>> - }
>>> + /* Set the event of proper data type monitoring */
>>> + ret = regmap_write(info->regmap, PPMU_V2_CH_EVx_TYPE(id),
>>> + edev->desc->data_type);
>>> + if (ret < 0)
>>> + return ret;
>>>
>>> /* Reset cycle counter/performance counter and enable PPMU */
>>> ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
>>> @@ -508,6 +496,7 @@ static int of_get_devfreq_events(struct device_node *np,
>>> struct device *dev = info->dev;
>>> struct device_node *events_np, *node;
>>> int i, j, count;
>>> + int ret;
>>>
>>> events_np = of_get_child_by_name(np, "events");
>>> if (!events_np) {
>>> @@ -544,6 +533,40 @@ static int of_get_devfreq_events(struct device_node *np,
>>> desc[j].driver_data = info;
>>>
>>> of_property_read_string(node, "event-name", &desc[j].name);
>>> + ret = of_property_read_u32(node, "event-data-type",
>>> + &desc[j].data_type);
>>> + if (ret) {
>>> + /* Set the event of proper data type counting.
>>> + * Check if the data type has been defined in DT,
>>> + * use default if not.
>>> + */
>>> + if (of_device_is_compatible(np,
>>> + "samsung,exynos-ppmu-v2")) {
>>
>> It is not proper to compare the compatible string again
>> in the device driver. Instead, you can define the ppmu device type
>> as following and then use 'struct of_device_id' in order to
>> identify the device type.
> I have been thinking about modifying the code in similar fashion as you
> did. Good to see similar approach. I'll take your changes with a small
> additional code, which sets the 'info->ppmu_type' before the for
> loop, as an additional patch. Would it be OK if I add you as an author
> and add Sign-off-by: Chanwoo Choi <cw00.choi@...sung.com>?
If you agree, just add the my signed-off-by on second line.
>
> Regards,
> Lukasz
>>
>> enum exynos_ppmu_type {
>> EXYNOS_TYPE_PPMU,
>> EXYNOS_TYPE_PPMU_V2,
>> };
>>
>> static const struct of_device_id exynos_ppmu_id_match[] = {
>> {
>> .compatible = "samsung,exynos-ppmu",
>> - .data = (void *)&exynos_ppmu_ops,
>> + .data = (void *)EXYNOS_TYPE_PPMU,
>> }, {
>> .compatible = "samsung,exynos-ppmu-v2",
>> - .data = (void *)&exynos_ppmu_v2_ops,
>> + .data = (void *)EXYNOS_TYPE_PPMU_V2,
>> },
>>
>>
>> The many device drivers in the mainline uses this code
>> in order to get the device type. You can refer the example
>> in the drivers/mfd/max14577.c.
>>
>> (snip)
>>
>>
>> Example, I add the example. but it is not tested.
>>
>> --- a/drivers/devfreq/event/exynos-ppmu.c
>> +++ b/drivers/devfreq/event/exynos-ppmu.c
>> @@ -16,6 +16,7 @@
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> #include <linux/of_address.h>
>> +#include <linux/of_device.h>
>> #include <linux/platform_device.h>
>> #include <linux/regmap.h>
>> #include <linux/suspend.h>
>> @@ -23,6 +24,11 @@
>>
>> #include "exynos-ppmu.h"
>>
>> +enum exynos_ppmu_type {
>> + EXYNOS_TYPE_PPMU,
>> + EXYNOS_TYPE_PPMU_V2,
>> +};
>> +
>> struct exynos_ppmu_data {
>> struct clk *clk;
>> };
>> @@ -36,6 +42,7 @@ struct exynos_ppmu {
>> struct regmap *regmap;
>>
>> struct exynos_ppmu_data ppmu;
>> + enum exynos_ppmu_type ppmu_type;
>> };
>>
>> #define PPMU_EVENT(name) \
>>
>> /* Reset cycle counter/performance counter and enable PPMU */
>> ret = regmap_read(info->regmap, PPMU_V2_PMNC, &pmnc);
>> @@ -483,31 +476,23 @@ static const struct devfreq_event_ops exynos_ppmu_v2_ops = {
>> static const struct of_device_id exynos_ppmu_id_match[] = {
>> {
>> .compatible = "samsung,exynos-ppmu",
>> - .data = (void *)&exynos_ppmu_ops,
>> + .data = (void *)EXYNOS_TYPE_PPMU,
>> }, {
>> .compatible = "samsung,exynos-ppmu-v2",
>> - .data = (void *)&exynos_ppmu_v2_ops,
>> + .data = (void *)EXYNOS_TYPE_PPMU_V2,
>> },
>> { /* sentinel */ },
>> };
>> MODULE_DEVICE_TABLE(of, exynos_ppmu_id_match);
>>
>> -static struct devfreq_event_ops *exynos_bus_get_ops(struct device_node *np)
>> -{
>> - const struct of_device_id *match;
>> -
>> - match = of_match_node(exynos_ppmu_id_match, np);
>> - return (struct devfreq_event_ops *)match->data;
>> -}
>> -
>> static int of_get_devfreq_events(struct device_node *np,
>> struct exynos_ppmu *info)
>> {
>> struct devfreq_event_desc *desc;
>> - struct devfreq_event_ops *event_ops;
>> struct device *dev = info->dev;
>> struct device_node *events_np, *node;
>> int i, j, count;
>>
>> events_np = of_get_child_by_name(np, "events");
>> if (!events_np) {
>> @@ -515,7 +500,6 @@ static int of_get_devfreq_events(struct device_node *np,
>> "failed to get child node of devfreq-event devices\n");
>> return -EINVAL;
>> }
>> - event_ops = exynos_bus_get_ops(np);
>>
>> count = of_get_child_count(events_np);
>> desc = devm_kcalloc(dev, count, sizeof(*desc), GFP_KERNEL);
>> @@ -540,11 +524,38 @@ static int of_get_devfreq_events(struct device_node *np,
>> continue;
>> }
>>
>> - desc[j].ops = event_ops;
>> + switch (info->ppmu_type) {
>> + case EXYNOS_TYPE_PPMU:
>> + desc[j].ops = &exynos_ppmu_ops;
>> + break;
>> + case EXYNOS_TYPE_PPMU_V2:
>> + desc[j].ops = &exynos_ppmu_v2_ops;
>> + break;
>> + }
>> +
>>
>>
>
>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
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