* Re: [PATCH v4 05/20] PM / devfreq: Add new passive governor
@ 2015-12-14 9:04 MyungJoo Ham
2015-12-18 1:27 ` Chanwoo Choi
0 siblings, 1 reply; 3+ messages in thread
From: MyungJoo Ham @ 2015-12-14 9:04 UTC (permalink / raw)
To: 최찬우,
크쉬시토프,
kgene
Cc: 박경민,
robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, linux,
tjakobi, linux.amoon, linux-kernel, linux-pm, linux-samsung-soc,
devicetree
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=utf-8, Size: 7489 bytes --]
>
> This patch adds the new passive governor for DEVFREQ framework. The following
> governors are already present and used for DVFS (Dynamic Voltage and Frequency
> Scaling) drivers. The following governors are independently used for one device
> driver which don't give the influence to other device drviers and also don't
> receive the effect from other device drivers.
> - ondemand / performance / powersave / userspace
>
> The passive governor depends on operation of parent driver with specific
> governos extremely and is not able to decide the new frequency by oneself.
> According to the decided new frequency of parent driver with governor,
> the passive governor uses it to decide the appropriate frequency for own
> device driver. The passive governor must need the following information
> from device tree:
> - the source clock and OPP tables
> - the instance of parent device
>
> For exameple,
> there are one more devfreq device drivers which need to change their source
> clock according to their utilization on runtime. But, they share the same
> power line (e.g., regulator). So, specific device driver is operated as parent
> with ondemand governor and then the rest device driver with passive governor
> is influenced by parent device.
>
> Suggested-by: Myungjoo Ham <myungjoo.ham@samsung.com>
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> [linux.amoon: Tested on Odroid U3]
> Tested-by: Anand Moon <linux.amoon@gmail.com>
> ---
> drivers/devfreq/Kconfig | 9 ++++
> drivers/devfreq/Makefile | 1 +
> drivers/devfreq/devfreq.c | 47 ++++++++++++++++
> drivers/devfreq/governor_passive.c | 108 +++++++++++++++++++++++++++++++++++++
> include/linux/devfreq.h | 15 ++++++
> 5 files changed, 180 insertions(+)
> create mode 100644 drivers/devfreq/governor_passive.c
>
> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
> index 55ec774f794c..d03f635a93e1 100644
> --- a/drivers/devfreq/Kconfig
> +++ b/drivers/devfreq/Kconfig
> @@ -64,6 +64,15 @@ config DEVFREQ_GOV_USERSPACE
> Otherwise, the governor does not change the frequnecy
> given at the initialization.
>
> +config DEVFREQ_GOV_PASSIVE
> + tristate "Passive"
> + help
> + Sets the frequency by other governors (simple_ondemand, performance,
> + powersave, usersapce) of a parent devfreq device. This governor
> + always has the dependency on the chosen frequency from paired
> + governor. This governor does not change the frequency by oneself
> + through sysfs entry.
Sets the frequency based on the frequency of its parent devfreq
device. This governor does not change the frequency by itself
through sysfs entries.
> +
> comment "DEVFREQ Drivers"
>
> config ARM_EXYNOS_BUS_DEVFREQ
> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
> index 375ebbb4fcfb..f81c313b4b79 100644
> --- a/drivers/devfreq/Makefile
> +++ b/drivers/devfreq/Makefile
[]
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 984c5e9e7bdd..15e58779e4c0 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -190,6 +190,31 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
>
> /* Load monitoring helper functions for governors use */
>
> +static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq)
> +{
> + struct devfreq *passive;
> + unsigned long rate;
> + int ret;
> +
> + list_for_each_entry(passive, &devfreq->passive_dev_list, passive_node) {
> + if (!passive->governor)
> + continue;
> + rate = freq;
> +
> + ret = passive->governor->get_target_freq(passive, &rate);
> + if (ret)
> + return ret;
> +
> + ret = passive->profile->target(passive->dev.parent, &rate, 0);
> + if (ret)
> + return ret;
> +
> + passive->previous_freq = rate;
> + }
> +
> + return 0;
> +}
> +
> /**
> * update_devfreq() - Reevaluate the device and configure frequency.
> * @devfreq: the devfreq instance.
> @@ -233,10 +258,18 @@ int update_devfreq(struct devfreq *devfreq)
> flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
> }
>
> + if (!list_empty(&devfreq->passive_dev_list)
> + && devfreq->previous_freq > freq)
> + update_devfreq_passive(devfreq, freq);
> +
Could you please comment somewhere appropriate
that the dependent is going to be changed
before its parent if the frequency is going down.
(and after if going up)
And state why as well.
And, is this viable universally?
> err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
> if (err)
> return err;
>
> + if (!list_empty(&devfreq->passive_dev_list)
> + && devfreq->previous_freq < freq)
> + update_devfreq_passive(devfreq, freq);
> +
> if (devfreq->profile->freq_table)
> if (devfreq_update_status(devfreq, freq))
> dev_err(&devfreq->dev,
> @@ -442,6 +475,10 @@ static void _remove_devfreq(struct devfreq *devfreq)
> return;
> }
> list_del(&devfreq->node);
> + list_del(&devfreq->passive_node);
> + if (!list_empty(&devfreq->passive_dev_list))
> + list_del_init(&devfreq->passive_dev_list);
> +
> mutex_unlock(&devfreq_list_lock);
>
> if (devfreq->governor)
> @@ -559,6 +596,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
> goto err_init;
> }
>
> + if (!strncmp(devfreq->governor_name, "passive", 7)) {
> + struct devfreq *parent_devfreq =
> + ((struct devfreq_passive_data *)data)->parent;
> +
> + list_add(&devfreq->passive_node,
> + &parent_devfreq->passive_dev_list);
> + } else {
> + INIT_LIST_HEAD(&devfreq->passive_dev_list);
> + }
> +
> return devfreq;
>
> err_init:
This code has become too much invasive to devfreq.c
while being too special for the passive governor.
Why don't you add notifier chain to devfreq.c, which can be used
by anyone else as well, and use that notifier for passive governor?
You may refer to "cpufreq_register_notifier()" with
CPUFREQ_TRANSITION_NOTIFIER.
> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> new file mode 100644
Then, utilizing notifier-block at governor_passive.c becomes possible.
You will also be able to write any frequency deciding code
inside governor_passive.c as well, not in devfreq.c.
> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
> index 6fa02a20eb63..95c54578a1b4 100644
> --- a/include/linux/devfreq.h
> +++ b/include/linux/devfreq.h
> @@ -177,6 +177,9 @@ struct devfreq {
> unsigned int *trans_table;
> unsigned long *time_in_state;
> unsigned long last_stat_updated;
> +
> + struct list_head passive_dev_list;
> + struct list_head passive_node;
> };
You will need only one notifier head here.
>
> #if defined(CONFIG_PM_DEVFREQ)
> @@ -241,6 +244,18 @@ struct devfreq_simple_ondemand_data {
> };
> #endif
>
> +/**
> + * struct devfreq_passive_data - void *data fed to struct devfreq
> + * and devfreq_add_device
> + * @parent: The parent devfreq device.
> + *
> + * If the fed devfreq_passive_data pointer is NULL to the governor,
> + * the governor return ERROR.
> + */
> +struct devfreq_passive_data {
> + struct devfreq *parent;
> +};
> +
Please enclose the above with #if
> #else /* !CONFIG_PM_DEVFREQ */
> static inline struct devfreq *devfreq_add_device(struct device *dev,
> struct devfreq_dev_profile *profile,
> --
> 1.9.1
>
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v4 05/20] PM / devfreq: Add new passive governor
2015-12-14 9:04 [PATCH v4 05/20] PM / devfreq: Add new passive governor MyungJoo Ham
@ 2015-12-18 1:27 ` Chanwoo Choi
0 siblings, 0 replies; 3+ messages in thread
From: Chanwoo Choi @ 2015-12-18 1:27 UTC (permalink / raw)
To: myungjoo.ham, 크쉬시토프, kgene
Cc: 박경민,
robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, linux,
tjakobi, linux.amoon, linux-kernel, linux-pm, linux-samsung-soc,
devicetree
On 2015년 12월 14일 18:04, MyungJoo Ham wrote:
>>
>> This patch adds the new passive governor for DEVFREQ framework. The following
>> governors are already present and used for DVFS (Dynamic Voltage and Frequency
>> Scaling) drivers. The following governors are independently used for one device
>> driver which don't give the influence to other device drviers and also don't
>> receive the effect from other device drivers.
>> - ondemand / performance / powersave / userspace
>>
>> The passive governor depends on operation of parent driver with specific
>> governos extremely and is not able to decide the new frequency by oneself.
>> According to the decided new frequency of parent driver with governor,
>> the passive governor uses it to decide the appropriate frequency for own
>> device driver. The passive governor must need the following information
>> from device tree:
>> - the source clock and OPP tables
>> - the instance of parent device
>>
>> For exameple,
>> there are one more devfreq device drivers which need to change their source
>> clock according to their utilization on runtime. But, they share the same
>> power line (e.g., regulator). So, specific device driver is operated as parent
>> with ondemand governor and then the rest device driver with passive governor
>> is influenced by parent device.
>>
>> Suggested-by: Myungjoo Ham <myungjoo.ham@samsung.com>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
>> [linux.amoon: Tested on Odroid U3]
>> Tested-by: Anand Moon <linux.amoon@gmail.com>
>> ---
>> drivers/devfreq/Kconfig | 9 ++++
>> drivers/devfreq/Makefile | 1 +
>> drivers/devfreq/devfreq.c | 47 ++++++++++++++++
>> drivers/devfreq/governor_passive.c | 108 +++++++++++++++++++++++++++++++++++++
>> include/linux/devfreq.h | 15 ++++++
>> 5 files changed, 180 insertions(+)
>> create mode 100644 drivers/devfreq/governor_passive.c
>>
>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
>> index 55ec774f794c..d03f635a93e1 100644
>> --- a/drivers/devfreq/Kconfig
>> +++ b/drivers/devfreq/Kconfig
>> @@ -64,6 +64,15 @@ config DEVFREQ_GOV_USERSPACE
>> Otherwise, the governor does not change the frequnecy
>> given at the initialization.
>>
>> +config DEVFREQ_GOV_PASSIVE
>> + tristate "Passive"
>> + help
>> + Sets the frequency by other governors (simple_ondemand, performance,
>> + powersave, usersapce) of a parent devfreq device. This governor
>> + always has the dependency on the chosen frequency from paired
>> + governor. This governor does not change the frequency by oneself
>> + through sysfs entry.
>
> Sets the frequency based on the frequency of its parent devfreq
> device. This governor does not change the frequency by itself
> through sysfs entries.
OK. I'll modify it.
>
>> +
>> comment "DEVFREQ Drivers"
>>
>> config ARM_EXYNOS_BUS_DEVFREQ
>> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
>> index 375ebbb4fcfb..f81c313b4b79 100644
>> --- a/drivers/devfreq/Makefile
>> +++ b/drivers/devfreq/Makefile
> []
>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
>> index 984c5e9e7bdd..15e58779e4c0 100644
>> --- a/drivers/devfreq/devfreq.c
>> +++ b/drivers/devfreq/devfreq.c
>> @@ -190,6 +190,31 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
>>
>> /* Load monitoring helper functions for governors use */
>>
>> +static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq)
>> +{
>> + struct devfreq *passive;
>> + unsigned long rate;
>> + int ret;
>> +
>> + list_for_each_entry(passive, &devfreq->passive_dev_list, passive_node) {
>> + if (!passive->governor)
>> + continue;
>> + rate = freq;
>> +
>> + ret = passive->governor->get_target_freq(passive, &rate);
>> + if (ret)
>> + return ret;
>> +
>> + ret = passive->profile->target(passive->dev.parent, &rate, 0);
>> + if (ret)
>> + return ret;
>> +
>> + passive->previous_freq = rate;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> /**
>> * update_devfreq() - Reevaluate the device and configure frequency.
>> * @devfreq: the devfreq instance.
>> @@ -233,10 +258,18 @@ int update_devfreq(struct devfreq *devfreq)
>> flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
>> }
>>
>> + if (!list_empty(&devfreq->passive_dev_list)
>> + && devfreq->previous_freq > freq)
>> + update_devfreq_passive(devfreq, freq);
>> +
>
> Could you please comment somewhere appropriate
> that the dependent is going to be changed
> before its parent if the frequency is going down.
> (and after if going up)
> And state why as well.
I use the DEVFREQ_TRANSITION_NOTIFIER instead of this implementation.
>
> And, is this viable universally?
>
>> err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
>> if (err)
>> return err;
>>
>> + if (!list_empty(&devfreq->passive_dev_list)
>> + && devfreq->previous_freq < freq)
>> + update_devfreq_passive(devfreq, freq);
>> +
>> if (devfreq->profile->freq_table)
>> if (devfreq_update_status(devfreq, freq))
>> dev_err(&devfreq->dev,
>> @@ -442,6 +475,10 @@ static void _remove_devfreq(struct devfreq *devfreq)
>> return;
>> }
>> list_del(&devfreq->node);
>> + list_del(&devfreq->passive_node);
>> + if (!list_empty(&devfreq->passive_dev_list))
>> + list_del_init(&devfreq->passive_dev_list);
>> +
>> mutex_unlock(&devfreq_list_lock);
>>
>> if (devfreq->governor)
>> @@ -559,6 +596,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
>> goto err_init;
>> }
>>
>> + if (!strncmp(devfreq->governor_name, "passive", 7)) {
>> + struct devfreq *parent_devfreq =
>> + ((struct devfreq_passive_data *)data)->parent;
>> +
>> + list_add(&devfreq->passive_node,
>> + &parent_devfreq->passive_dev_list);
>> + } else {
>> + INIT_LIST_HEAD(&devfreq->passive_dev_list);
>> + }
>> +
>> return devfreq;
>>
>> err_init:
>
> This code has become too much invasive to devfreq.c
> while being too special for the passive governor.
I agree. I'll implement again with notifier.
>
> Why don't you add notifier chain to devfreq.c, which can be used
> by anyone else as well, and use that notifier for passive governor?
> You may refer to "cpufreq_register_notifier()" with
> CPUFREQ_TRANSITION_NOTIFIER.
OK. I'll add the new notifier of DEVFREQ_TRANSITION_NOTIFIER
The list of supported notification:
DEVFREQ_PRECHANGE
DEVFREQ_POSTCHANGE
>
>> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
>> new file mode 100644
>
> Then, utilizing notifier-block at governor_passive.c becomes possible.
>
> You will also be able to write any frequency deciding code
> inside governor_passive.c as well, not in devfreq.c.
OK, I'll use DEVFREQ_TRANSITION_NOTIFIER for passive governor.
>
>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
>> index 6fa02a20eb63..95c54578a1b4 100644
>> --- a/include/linux/devfreq.h
>> +++ b/include/linux/devfreq.h
>> @@ -177,6 +177,9 @@ struct devfreq {
>> unsigned int *trans_table;
>> unsigned long *time_in_state;
>> unsigned long last_stat_updated;
>> +
>> + struct list_head passive_dev_list;
>> + struct list_head passive_node;
>> };
>
> You will need only one notifier head here.
OK.
>
>>
>> #if defined(CONFIG_PM_DEVFREQ)
>> @@ -241,6 +244,18 @@ struct devfreq_simple_ondemand_data {
>> };
>> #endif
>>
>> +/**
>> + * struct devfreq_passive_data - void *data fed to struct devfreq
>> + * and devfreq_add_device
>> + * @parent: The parent devfreq device.
>> + *
>> + * If the fed devfreq_passive_data pointer is NULL to the governor,
>> + * the governor return ERROR.
>> + */
>> +struct devfreq_passive_data {
>> + struct devfreq *parent;
>> +};
>> +
>
> Please enclose the above with #if
OK.
Thanks,
Chanwoo Choi
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v4 00/20] PM / devferq: Add generic exynos bus frequency driver and new passive governor
@ 2015-12-14 6:38 Chanwoo Choi
2015-12-14 6:38 ` [PATCH v4 05/20] PM / devfreq: Add " Chanwoo Choi
0 siblings, 1 reply; 3+ messages in thread
From: Chanwoo Choi @ 2015-12-14 6:38 UTC (permalink / raw)
To: myungjoo.ham, k.kozlowski, kgene
Cc: kyungmin.park, robh+dt, pawel.moll, mark.rutland, ijc+devicetree,
galak, linux, tjakobi, linux.amoon, cw00.choi, linux-kernel,
linux-pm, linux-samsung-soc, devicetree
This patch-set includes the two features as following. The generic exynos bus
frequency driver is able to support almost Exynos SoCs for bus frequency
scaling. And the new passive governor is able to make the dependency on
between devices for frequency/voltage scaling. I had posted the patch-set[2]
with the similiar concept. This is is revised version for exynos bus frequency.
- Generic exynos bus frequency driver
- New passive governor of DEVFREQ framework
Depend on:
- next-20151210 tag of linux-next (master branch).
- Merge the latest devfreq patches on devfreq.git[2] (for-rafael branch).
[1] https://git.kernel.org/cgit/linux/kernel/git/mzx/devfreq.git/ (branch: for-rafael)
[2] https://lkml.org/lkml/2015/1/7/872
: [PATCHv3 0/8] devfreq: Add generic exynos memory-bus frequency driver
Changes from v3:
(https://lkml.org/lkml/2015/12/11/75)
- Add the reviewed-by tag from Krzysztof Kozlowski (patch2/3/13/14/15/16/17)
- Fix typo of the description on patch14
- Modify the subject and description of patch17
- Reorder the 'bus_xxx' device tree node alphabetically in
both exynos3250-rinato/monk.dts and exynos4412-trats/odroidu3
Changes from v2:
(https://lkml.org/lkml/2015/12/8/869)
- Fix typo on documentation
- Modify the more appropriate sentence on patch description
- Add the detailed description about both parent and passive bus device
- Modify the DMC frequency for Exynos4x12 DMC bus (200MHz -> 267MHz)
- Modify the voltage of 200MHz was included in Exynos3250 DMC bus (800mV -> 825mV)
- Rename OPP nodes as 'opp@<opp-hz>'
- Delete the duplicate 'opp-microvolt' property of passive devfreq device
- Reorder the 'bus_xxx' device tree node alphabetically in exynos3250-rinato/monk.dts
- Reorder the 'bus_xxx' device tree node alphabetically in exynos4412-trats/odroidu3
- Add new exynos4412-ppmu-common.dtsi to remove the duplicate PPMU dt node
on rinato/monk/trats2/odroid-u3 board
- Add the log message if bus device is registered to devfreq framework successfully
- Add the reviewed-by tag from Krzysztof Kozlowski
- Add the tested-by tag from Anand Moon on Odroid U3
- Add 'SAMSUNG BUS FREQUENCY DRIVER' entry to MAINTAINERS
Changes from v1:
(https://lkml.org/lkml/2015/11/26/260)
- Check whether the instance of regulator is NULL or not
when executing regulator_disable() because of only parent
devfreq device has the regulator instance. After fixing it,
the wake-up from suspend state is well working. (patch1)
- Fix bug which checks 'bus-clk' instead of 'bus->regulator'
after calling devm_clk_get() (on patch1)
- Update the documentation to remove the description about
DEVFREQ-EVENT subsystem (on patch2)
- Add the full name of DMC (Dynamic Memory Controller) (on patch2)
- Modify the detailed correlation of buses for Exynos3250
on documentation (patch2)
- Add the MFC bus node for Exynos3250 (on patch11, patch12)
- Fix the duplicate frequency of bus_display on Exynos4x12.dtsi
- Add the PPMU node for exynos4412-odroidu3
- Add the support of bus frequency for exynos4412-odroidu3
Detailed descirption for patch-set:
1. Add generic exynos bus frequency driver
: This patch-set adds the generic exynos bus frequency driver for AXI bus
of sub-blocks in exynos SoC. The Samsung Exynos SoC have the common
architecture for bus between DRAM and sub-blocks in SoC.
There are the different buses according to Exynos SoC because Exynos SoC
has the differnt sub-blocks and bus speed. In spite of this difference
among Exynos SoCs, this driver is able to support almost Exynos SoC by adding
unique data of each bus in the devicetree file.
In devicetree, each bus node has a bus clock, regulator, operation-point
and devfreq-event devices which measure the utilization of each bus block.
For example,
- The bus of DMC block in exynos3250.dtsi are listed below:
bus_dmc: bus_dmc {
compatible = "samsung,exynos-bus";
clocks = <&cmu_dmc CLK_DIV_DMC>;
clock-names = "bus";
operating-points-v2 = <&bus_dmc_opp_table>;
status = "disabled";
};
bus_dmc_opp_table: opp_table1 {
compatible = "operating-points-v2";
opp-shared;
opp@50000000 {
opp-hz = /bits/ 64 <50000000>;
opp-microvolt = <800000>;
};
opp@100000000 {
opp-hz = /bits/ 64 <100000000>;
opp-microvolt = <800000>;
};
opp@134000000 {
opp-hz = /bits/ 64 <134000000>;
opp-microvolt = <800000>;
};
opp@200000000 {
opp-hz = /bits/ 64 <200000000>;
opp-microvolt = <825000>;
};
opp@400000000 {
opp-hz = /bits/ 64 <400000000>;
opp-microvolt = <875000>;
};
};
- Usage case to handle the frequency and voltage of bus on runtime
in exynos3250-rinato.dts are listed below:
&bus_dmc {
devfreq-events = <&ppmu_dmc0_3>, <&ppmu_dmc1_3>;
vdd-supply = <&buck1_reg>; /* VDD_MIF */
status = "okay";
};
2. Add new passive governor of DEVFREQ framework (patch5-patch7)
: This patch-set add the new passive governor for DEVFREQ framework.
The existing governors (ondemand, performance and so on) are used for DVFS
(Dynamic Voltage and Frequency Scaling) drivers. The existing governors
are independently used for specific device driver which don't give the
influence to other device drviers and also don't receive the effect from
other device drivers.
The passive governor depends on operation of parent driver with existing
governors(ondemand, performance and so on) extremely and is not able to
decide the new frequency by oneself. According to the decided new frequency
of parent driver with governor, the passive governor uses it to decide
the appropriate frequency for own device driver. The passive governor
must need the following information from device tree:
For exameple,
There are one more bus device drivers in Exynos3250 which need to
change their source clock according to their utilization on runtime.
But, they share the same power line (e.g., regulator). So, LEFTBUS bus
driver is operated as parent with ondemand governor and then the rest
device driver with passive governor.
The buses of Internal block in exynos3250.dtsi are listed below:
When LEFTBUS bus driver (parent) changes the bus frequency with
ondemand governor on runtime, the rest bus devices which sharing
the same power line (VDD_INT) will change the each bus frequency
according to the decision of LEFTBUS bus driver (parent).
- INT (Internal) block
: VDD_INT |--- LEFTBUS
|--- PERIL
|--- MFC
|--- G3D
|--- RIGHTBUS
|--- FSYS
|--- LCD0
|--- PERIR
|--- ISP
|--- CAM
- The buss of INT block in exynos3250.dtsi are listed below:
bus_leftbus: bus_leftbus {
compatible = "samsung,exynos-bus";
clocks = <&cmu CLK_DIV_GDL>;
clock-names = "bus";
operating-points-v2 = <&bus_leftbus_opp_table>;
status = "disabled";
};
bus_rightbus: bus_rightbus {
compatible = "samsung,exynos-bus";
clocks = <&cmu CLK_DIV_GDR>;
clock-names = "bus";
operating-points-v2 = <&bus_leftbus_opp_table>;
status = "disabled";
};
(Omit the rest bus dt node)
- Usage case to handle the frequency and voltage of bus on runtime
in exynos3250-rinato.dts are listed below:
/* Parent bus device of VDD_INT */
&bus_leftbus {
devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>;
vdd-supply = <&buck3_reg>;
status = "okay";
};
/* Passive bus device depend on LEFTBUS bus. */
&bus_rightbus {
devfreq = <&bus_leftbus>; /* 'devfreq' property indicates
the phandle of parent device. */
status = "okay";
};
(Omit the rest bus dt node)
Chanwoo Choi (20):
PM / devfreq: exynos: Add generic exynos bus frequency driver
PM / devfreq: exynos: Add documentation for generic exynos bus frequency driver
ARM: dts: Add DMC bus node for Exynos3250
ARM: dts: Add DMC bus frequency for exynos3250-rinato/monk
PM / devfreq: Add new passive governor
PM / devfreq: Add devfreq_get_devfreq_by_phandle()
PM / devfreq: Show the related information according to governor type
PM / devfreq: exynos: Add support of bus frequency of sub-blocks using passive governor
PM / devfreq: exynos: Update documentation for bus devices using passive governor
PM / devfreq: exynos: Add the detailed correlation between sub-blocks and power line
PM / devfreq: exynos: Remove unused exynos4/5 busfreq driver
MAINTAINERS: Add samsung bus frequency driver entry
ARM: dts: Add bus nodes using VDD_INT for Exynos3250
ARM: dts: Add bus nodes using VDD_MIF for Exynos4x12
ARM: dts: Add bus nodes using VDD_INT for Exynos4x12
ARM: dts: Add bus nodes using VDD_MIF for Exynos4210
ARM: dts: Add exynos4412-ppmu-common dtsi to delete duplicate PPMU nodes
ARM: dts: Add support of bus frequency using VDD_INT for exynos3250-rinato
ARM: dts: Expand the voltage range of buck1/3 regulator for exynos4412-odroidu3
ARM: dts: Add support of bus frequency for exynos4412-trats/odroidu3
.../devicetree/bindings/devfreq/exynos-bus.txt | 388 +++++++
MAINTAINERS | 9 +
arch/arm/boot/dts/exynos3250-monk.dts | 47 +-
arch/arm/boot/dts/exynos3250-rinato.dts | 88 +-
arch/arm/boot/dts/exynos3250.dtsi | 181 ++++
arch/arm/boot/dts/exynos4210.dtsi | 159 +++
arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 54 +-
arch/arm/boot/dts/exynos4412-ppmu-common.dtsi | 50 +
arch/arm/boot/dts/exynos4412-trats2.dts | 88 +-
arch/arm/boot/dts/exynos4x12.dtsi | 174 ++++
drivers/devfreq/Kconfig | 37 +-
drivers/devfreq/Makefile | 2 +
drivers/devfreq/devfreq.c | 120 ++-
drivers/devfreq/exynos/Makefile | 3 +-
drivers/devfreq/exynos/exynos-bus.c | 556 +++++++++++
drivers/devfreq/exynos/exynos4_bus.c | 1055 --------------------
drivers/devfreq/exynos/exynos4_bus.h | 110 --
drivers/devfreq/exynos/exynos5_bus.c | 431 --------
drivers/devfreq/exynos/exynos_ppmu.c | 119 ---
drivers/devfreq/exynos/exynos_ppmu.h | 86 --
drivers/devfreq/governor.h | 7 +
drivers/devfreq/governor_passive.c | 109 ++
drivers/devfreq/governor_performance.c | 1 +
drivers/devfreq/governor_powersave.c | 1 +
drivers/devfreq/governor_simpleondemand.c | 1 +
drivers/devfreq/governor_userspace.c | 1 +
include/linux/devfreq.h | 26 +
27 files changed, 1955 insertions(+), 1948 deletions(-)
create mode 100644 Documentation/devicetree/bindings/devfreq/exynos-bus.txt
create mode 100644 arch/arm/boot/dts/exynos4412-ppmu-common.dtsi
create mode 100644 drivers/devfreq/exynos/exynos-bus.c
delete mode 100644 drivers/devfreq/exynos/exynos4_bus.c
delete mode 100644 drivers/devfreq/exynos/exynos4_bus.h
delete mode 100644 drivers/devfreq/exynos/exynos5_bus.c
delete mode 100644 drivers/devfreq/exynos/exynos_ppmu.c
delete mode 100644 drivers/devfreq/exynos/exynos_ppmu.h
create mode 100644 drivers/devfreq/governor_passive.c
--
1.9.1
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v4 05/20] PM / devfreq: Add new passive governor
2015-12-14 6:38 [PATCH v4 00/20] PM / devferq: Add generic exynos bus frequency driver and " Chanwoo Choi
@ 2015-12-14 6:38 ` Chanwoo Choi
0 siblings, 0 replies; 3+ messages in thread
From: Chanwoo Choi @ 2015-12-14 6:38 UTC (permalink / raw)
To: myungjoo.ham, k.kozlowski, kgene
Cc: kyungmin.park, robh+dt, pawel.moll, mark.rutland, ijc+devicetree,
galak, linux, tjakobi, linux.amoon, cw00.choi, linux-kernel,
linux-pm, linux-samsung-soc, devicetree
This patch adds the new passive governor for DEVFREQ framework. The following
governors are already present and used for DVFS (Dynamic Voltage and Frequency
Scaling) drivers. The following governors are independently used for one device
driver which don't give the influence to other device drviers and also don't
receive the effect from other device drivers.
- ondemand / performance / powersave / userspace
The passive governor depends on operation of parent driver with specific
governos extremely and is not able to decide the new frequency by oneself.
According to the decided new frequency of parent driver with governor,
the passive governor uses it to decide the appropriate frequency for own
device driver. The passive governor must need the following information
from device tree:
- the source clock and OPP tables
- the instance of parent device
For exameple,
there are one more devfreq device drivers which need to change their source
clock according to their utilization on runtime. But, they share the same
power line (e.g., regulator). So, specific device driver is operated as parent
with ondemand governor and then the rest device driver with passive governor
is influenced by parent device.
Suggested-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[linux.amoon: Tested on Odroid U3]
Tested-by: Anand Moon <linux.amoon@gmail.com>
---
drivers/devfreq/Kconfig | 9 ++++
drivers/devfreq/Makefile | 1 +
drivers/devfreq/devfreq.c | 47 ++++++++++++++++
drivers/devfreq/governor_passive.c | 108 +++++++++++++++++++++++++++++++++++++
include/linux/devfreq.h | 15 ++++++
5 files changed, 180 insertions(+)
create mode 100644 drivers/devfreq/governor_passive.c
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index 55ec774f794c..d03f635a93e1 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -64,6 +64,15 @@ config DEVFREQ_GOV_USERSPACE
Otherwise, the governor does not change the frequnecy
given at the initialization.
+config DEVFREQ_GOV_PASSIVE
+ tristate "Passive"
+ help
+ Sets the frequency by other governors (simple_ondemand, performance,
+ powersave, usersapce) of a parent devfreq device. This governor
+ always has the dependency on the chosen frequency from paired
+ governor. This governor does not change the frequency by oneself
+ through sysfs entry.
+
comment "DEVFREQ Drivers"
config ARM_EXYNOS_BUS_DEVFREQ
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
index 375ebbb4fcfb..f81c313b4b79 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND) += governor_simpleondemand.o
obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE) += governor_performance.o
obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE) += governor_powersave.o
obj-$(CONFIG_DEVFREQ_GOV_USERSPACE) += governor_userspace.o
+obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o
# DEVFREQ Drivers
obj-$(CONFIG_ARCH_EXYNOS) += exynos/
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 984c5e9e7bdd..15e58779e4c0 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -190,6 +190,31 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
/* Load monitoring helper functions for governors use */
+static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq)
+{
+ struct devfreq *passive;
+ unsigned long rate;
+ int ret;
+
+ list_for_each_entry(passive, &devfreq->passive_dev_list, passive_node) {
+ if (!passive->governor)
+ continue;
+ rate = freq;
+
+ ret = passive->governor->get_target_freq(passive, &rate);
+ if (ret)
+ return ret;
+
+ ret = passive->profile->target(passive->dev.parent, &rate, 0);
+ if (ret)
+ return ret;
+
+ passive->previous_freq = rate;
+ }
+
+ return 0;
+}
+
/**
* update_devfreq() - Reevaluate the device and configure frequency.
* @devfreq: the devfreq instance.
@@ -233,10 +258,18 @@ int update_devfreq(struct devfreq *devfreq)
flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
}
+ if (!list_empty(&devfreq->passive_dev_list)
+ && devfreq->previous_freq > freq)
+ update_devfreq_passive(devfreq, freq);
+
err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
if (err)
return err;
+ if (!list_empty(&devfreq->passive_dev_list)
+ && devfreq->previous_freq < freq)
+ update_devfreq_passive(devfreq, freq);
+
if (devfreq->profile->freq_table)
if (devfreq_update_status(devfreq, freq))
dev_err(&devfreq->dev,
@@ -442,6 +475,10 @@ static void _remove_devfreq(struct devfreq *devfreq)
return;
}
list_del(&devfreq->node);
+ list_del(&devfreq->passive_node);
+ if (!list_empty(&devfreq->passive_dev_list))
+ list_del_init(&devfreq->passive_dev_list);
+
mutex_unlock(&devfreq_list_lock);
if (devfreq->governor)
@@ -559,6 +596,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
goto err_init;
}
+ if (!strncmp(devfreq->governor_name, "passive", 7)) {
+ struct devfreq *parent_devfreq =
+ ((struct devfreq_passive_data *)data)->parent;
+
+ list_add(&devfreq->passive_node,
+ &parent_devfreq->passive_dev_list);
+ } else {
+ INIT_LIST_HEAD(&devfreq->passive_dev_list);
+ }
+
return devfreq;
err_init:
diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
new file mode 100644
index 000000000000..7443ae4b92f9
--- /dev/null
+++ b/drivers/devfreq/governor_passive.c
@@ -0,0 +1,108 @@
+/*
+ * linux/drivers/devfreq/governor_passive.c
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * 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.
+ */
+
+#include <linux/devfreq.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/devfreq.h>
+#include "governor.h"
+
+static int devfreq_passive_get_target_freq(struct devfreq *passive,
+ unsigned long *freq)
+{
+ struct devfreq_passive_data *passive_data = passive->data;
+ struct devfreq *parent_devfreq = passive_data->parent;
+ unsigned long child_freq = ULONG_MAX;
+ int i, count;
+
+ /*
+ * Each devfreq has the OPP table. After deciding the new frequency
+ * from the governor of parent devfreq device, the passive governor
+ * need to get the index of new frequency on OPP table of parent
+ * device. And then the index is used for getting the suitable
+ * new frequency for passive devfreq device.
+ */
+
+ if (!passive->profile || !passive->profile->freq_table
+ || passive->profile->max_state <= 0)
+ return -EINVAL;
+
+ /*
+ * When new frequency is lower than previous frequency of parent
+ * devfreq device, passive governor get the correct frequency from OPP
+ * list of parent device. Because in this case, *freq is temporary
+ * value which is decided by ondemand governor.
+ */
+ if (parent_devfreq->previous_freq > *freq) {
+ struct dev_pm_opp *opp;
+ opp = devfreq_recommended_opp(parent_devfreq->dev.parent,
+ freq, 0);
+ if (IS_ERR_OR_NULL(opp))
+ return PTR_ERR(opp);
+ }
+
+ /*
+ * Get the OPP table's index of decided freqeuncy by governor
+ * of parent device.
+ */
+ for (i = 0; i < parent_devfreq->profile->max_state; i++)
+ if (parent_devfreq->profile->freq_table[i] == *freq)
+ break;
+
+ if (i == parent_devfreq->profile->max_state)
+ return -EINVAL;
+ count = passive->profile->max_state;
+
+ /* Get the suitable frequency by using index of parent device. */
+ if (i < passive->profile->max_state)
+ child_freq = passive->profile->freq_table[i];
+ else
+ child_freq = passive->profile->freq_table[count - 1];
+
+ /* Return the suitable frequency for passive device. */
+ *freq = child_freq;
+
+ return 0;
+}
+
+static int devfreq_passive_event_handler(struct devfreq *devfreq,
+ unsigned int event, void *data)
+{
+ return 0;
+}
+
+static struct devfreq_governor devfreq_passive = {
+ .name = "passive",
+ .get_target_freq = devfreq_passive_get_target_freq,
+ .event_handler = devfreq_passive_event_handler,
+};
+
+static int __init devfreq_passive_init(void)
+{
+ return devfreq_add_governor(&devfreq_passive);
+}
+subsys_initcall(devfreq_passive_init);
+
+static void __exit devfreq_passive_exit(void)
+{
+ int ret;
+
+ ret = devfreq_remove_governor(&devfreq_passive);
+ if (ret)
+ pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+ return;
+}
+module_exit(devfreq_passive_exit);
+
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_DESCRIPTION("DEVFREQ Passive governor");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 6fa02a20eb63..95c54578a1b4 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -177,6 +177,9 @@ struct devfreq {
unsigned int *trans_table;
unsigned long *time_in_state;
unsigned long last_stat_updated;
+
+ struct list_head passive_dev_list;
+ struct list_head passive_node;
};
#if defined(CONFIG_PM_DEVFREQ)
@@ -241,6 +244,18 @@ struct devfreq_simple_ondemand_data {
};
#endif
+/**
+ * struct devfreq_passive_data - void *data fed to struct devfreq
+ * and devfreq_add_device
+ * @parent: The parent devfreq device.
+ *
+ * If the fed devfreq_passive_data pointer is NULL to the governor,
+ * the governor return ERROR.
+ */
+struct devfreq_passive_data {
+ struct devfreq *parent;
+};
+
#else /* !CONFIG_PM_DEVFREQ */
static inline struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2015-12-14 9:04 [PATCH v4 05/20] PM / devfreq: Add new passive governor MyungJoo Ham
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2015-12-14 6:38 [PATCH v4 00/20] PM / devferq: Add generic exynos bus frequency driver and " Chanwoo Choi
2015-12-14 6:38 ` [PATCH v4 05/20] PM / devfreq: Add " Chanwoo Choi
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