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@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.
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@xxxxxxxxxxx>?
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;
> + }
> +
>
>
