Re: [PATCH v3 2/4] drivers: devfreq: events: extend events by type of counted data
From: Chanwoo Choi
Date: Tue Apr 30 2019 - 03:33:28 EST
Hi Lukasz,
On 19. 4. 19. ìí 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@xxxxxxxxxxxxxxxxxxx>
> ---
> 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.
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