Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
Hi Chanwoo, On 19.03.2014 10:47, Chanwoo Choi wrote: Hi Tomasz, On 03/19/2014 12:46 AM, Tomasz Figa wrote: On 17.03.2014 06:19, Chanwoo Choi wrote: Hi Tomasz, On 03/15/2014 02:35 AM, Tomasz Figa wrote: Hi Chanwoo, Mark, On 14.03.2014 11:56, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 07:35 PM, Mark Rutland wrote: On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization and then busfreq driver adjusts dynamically the operating frequency/voltage by using DEVFREQ Subsystem. Signed-off-by: Chanwoo Choi --- .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 ++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt new file mode 100644 index 000..2a83fcc --- /dev/null +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt @@ -0,0 +1,49 @@ + +Exynos4210/4x12 busfreq driver +- + +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage +scaling according to PPMU counters of memory controllers + +Required properties: +- compatible: should contain Exynos4 SoC type as follwoing: + - "samsung,exynos4x12-busfreq" for Exynos4x12 + - "samsung,exynos4210-busfreq" for Exynos4210 Is there a device called "busfreq"? What device does this binding describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). This still sounds like a description of the _driver_, not the _device_. The binding should describe the hardware, now the high level abstraction that software is going to build atop of it. It sounds like this is a binding for the DMC PPMU? Is the PPMU a component of the DMC, or is it bolted on the side? PPMU(Performance Profiling Monitoring Unit) is to profile performance event of various IP on Exynos4. Each PPMU provide perforamnce event for each IP. We can check various PPMU as following: PPMU_3D PPMU_ACP PPMU_CAMIF PPMU_CPU PPMU_DMC0 PPMU_DMC1 PPMU_FSYS PPMU_IMAGE PPMU_LCD0 PPMU_LCD1 PPMU_MFC_L PPMU_MFC_R PPMU_TV PPMU_LEFT_BUS PPMU_RIGHT_BUS DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 SoC. If we need to get memory bust utilization of DMC, we can get memory bus utilization from PPMU_DMC0/PPMU_DMC1. So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various PPMU list. Well, PPMUs and DMCs are separate hardware blocks found inside Exynos SoCs. Busfreq/devfreq is just a Linux-specific abstraction responsible for collecting data using PPMUs and controlling frequencies and voltages of appropriate power planes, vdd_int responsible for powering DMC0 and DMC1 blocks in this case. I knew already. I'm afraid that the binding you're proposing is unfortunately incorrect, because it represents the software abstraction, not the real hardware. What is exactly incorrect part of this patch? Device tree contains information about hardware, not about OS-specific drivers or subsystems. Busfreq/devfreq is not a hardware block, but a Linux-specific driver, so it's not suitable to be described by DT directly, especially considering the fact that in future it might be replaced by or merged with another subsystem. Only PPMUs are real hardware blocks present in the SoC. In addition, a SoC-level aspect of hardware description may be added, such as a list of power planes. See below for explanation. You means that PPMU must need separate framework from devfreq subsystem? If PPMU framework will be implemented, PPMU framework provides API to external device driver as common clk framework, regulator framework. And then,exynos4 busfreq with devfreq have to use PPMU framework to monitor memory utilization. Is this right? Not exactly. I'm just saying that in device tree, particular hardware blocks (such as PPMU) must be represented by their own nodes. This doesn't imply any particular implementation in code. DT bindings should be considered without any particular driver code in mind. The principle here is that with device tree describing all the information needed for Exynos bus frequency and power plane voltage scaling, y
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
Hi Tomasz, On 03/19/2014 12:46 AM, Tomasz Figa wrote: > On 17.03.2014 06:19, Chanwoo Choi wrote: >> Hi Tomasz, >> >> On 03/15/2014 02:35 AM, Tomasz Figa wrote: >>> Hi Chanwoo, Mark, >>> >>> On 14.03.2014 11:56, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 07:35 PM, Mark Rutland wrote: > On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: >> Hi Mark, >> >> On 03/14/2014 02:53 AM, Mark Rutland wrote: >>> On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization and then busfreq driver adjusts dynamically the operating frequency/voltage by using DEVFREQ Subsystem. Signed-off-by: Chanwoo Choi --- .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 ++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt new file mode 100644 index 000..2a83fcc --- /dev/null +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt @@ -0,0 +1,49 @@ + +Exynos4210/4x12 busfreq driver +- + +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage +scaling according to PPMU counters of memory controllers + +Required properties: +- compatible: should contain Exynos4 SoC type as follwoing: + - "samsung,exynos4x12-busfreq" for Exynos4x12 + - "samsung,exynos4210-busfreq" for Exynos4210 >>> >>> Is there a device called "busfreq"? What device does this binding >>> describe? >> >> I'll add detailed description of busfreq as following: >> >> "busfreq(bus frequendcy)" driver means that busfreq driver control >> dynamically >> memory bus frequency/voltage by checking memory bus utilization to >> optimize >> power-consumption. When checking memeory bus utilization, >> exynos4_busfreq driver >> would use PPMU(Performance Profiling Monitoring Units). > > This still sounds like a description of the _driver_, not the _device_. > The binding should describe the hardware, now the high level abstraction > that software is going to build atop of it. > > It sounds like this is a binding for the DMC PPMU? > > Is the PPMU a component of the DMC, or is it bolted on the side? PPMU(Performance Profiling Monitoring Unit) is to profile performance event of various IP on Exynos4. Each PPMU provide perforamnce event for each IP. We can check various PPMU as following: PPMU_3D PPMU_ACP PPMU_CAMIF PPMU_CPU PPMU_DMC0 PPMU_DMC1 PPMU_FSYS PPMU_IMAGE PPMU_LCD0 PPMU_LCD1 PPMU_MFC_L PPMU_MFC_R PPMU_TV PPMU_LEFT_BUS PPMU_RIGHT_BUS DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 SoC. If we need to get memory bust utilization of DMC, we can get memory bus utilization from PPMU_DMC0/PPMU_DMC1. So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various PPMU list. >>> >>> Well, PPMUs and DMCs are separate hardware blocks found inside Exynos SoCs. >>> Busfreq/devfreq is just a Linux-specific abstraction responsible for >>> collecting data using PPMUs and controlling frequencies and voltages of >>> appropriate power planes, vdd_int responsible for powering DMC0 and DMC1 >>> blocks in this case. >>> >> >> I knew already. >> >>> I'm afraid that the binding you're proposing is unfortunately incorrect, >>> because it represents the software abstraction, not the real hardware. >> >> What is exactly incorrect part of this patch? >> > > Device tree contains information about hardware, not about OS-specific > drivers or subsystems. Busfreq/devfreq is not a hardware block, but a > Linux-specific driver, so it's not suitable to be described by DT directly, > especially considering the fact that in future it might be replaced by or > merged with another subsystem. > > Only PPMUs are real hardware blocks present in the SoC. In addition, a > SoC-level aspect of hardware description may be added, such as a list of > power planes. See below for explanation. > You means that PPMU must need separate
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
On 17.03.2014 06:19, Chanwoo Choi wrote: Hi Tomasz, On 03/15/2014 02:35 AM, Tomasz Figa wrote: Hi Chanwoo, Mark, On 14.03.2014 11:56, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 07:35 PM, Mark Rutland wrote: On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization and then busfreq driver adjusts dynamically the operating frequency/voltage by using DEVFREQ Subsystem. Signed-off-by: Chanwoo Choi --- .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 ++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt new file mode 100644 index 000..2a83fcc --- /dev/null +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt @@ -0,0 +1,49 @@ + +Exynos4210/4x12 busfreq driver +- + +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage +scaling according to PPMU counters of memory controllers + +Required properties: +- compatible: should contain Exynos4 SoC type as follwoing: + - "samsung,exynos4x12-busfreq" for Exynos4x12 + - "samsung,exynos4210-busfreq" for Exynos4210 Is there a device called "busfreq"? What device does this binding describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). This still sounds like a description of the _driver_, not the _device_. The binding should describe the hardware, now the high level abstraction that software is going to build atop of it. It sounds like this is a binding for the DMC PPMU? Is the PPMU a component of the DMC, or is it bolted on the side? PPMU(Performance Profiling Monitoring Unit) is to profile performance event of various IP on Exynos4. Each PPMU provide perforamnce event for each IP. We can check various PPMU as following: PPMU_3D PPMU_ACP PPMU_CAMIF PPMU_CPU PPMU_DMC0 PPMU_DMC1 PPMU_FSYS PPMU_IMAGE PPMU_LCD0 PPMU_LCD1 PPMU_MFC_L PPMU_MFC_R PPMU_TV PPMU_LEFT_BUS PPMU_RIGHT_BUS DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 SoC. If we need to get memory bust utilization of DMC, we can get memory bus utilization from PPMU_DMC0/PPMU_DMC1. So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various PPMU list. Well, PPMUs and DMCs are separate hardware blocks found inside Exynos SoCs. Busfreq/devfreq is just a Linux-specific abstraction responsible for collecting data using PPMUs and controlling frequencies and voltages of appropriate power planes, vdd_int responsible for powering DMC0 and DMC1 blocks in this case. I knew already. I'm afraid that the binding you're proposing is unfortunately incorrect, because it represents the software abstraction, not the real hardware. What is exactly incorrect part of this patch? Device tree contains information about hardware, not about OS-specific drivers or subsystems. Busfreq/devfreq is not a hardware block, but a Linux-specific driver, so it's not suitable to be described by DT directly, especially considering the fact that in future it might be replaced by or merged with another subsystem. Only PPMUs are real hardware blocks present in the SoC. In addition, a SoC-level aspect of hardware description may be added, such as a list of power planes. See below for explanation. Instead, this should be separated into several independent bindings: - PPMU bindings to list all the PPMU instances present in the SoC and resources they need, - power plane bindings, which define a power plane in which multiple IP blocks might reside, can be monitored by one or more PPMU units and frequency and voltage of which can be configured according to determined performance level. Needed resources will be clocks and regulators to scale and probably also operating points. Then, exynos-busfreq driver should bind to such power planes, parse necessary data from DT (list of PPMUs and IP blocks, clocks, regulators and operating points) and register a devfreq entity. What is 'power plane'? I don't know 'power plane'. Power plane is a part of the SoC (set of IP blocks and buses) that is powered by the same power source. For e
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
Hi Tomasz, On 03/15/2014 02:35 AM, Tomasz Figa wrote: > Hi Chanwoo, Mark, > > On 14.03.2014 11:56, Chanwoo Choi wrote: >> Hi Mark, >> >> On 03/14/2014 07:35 PM, Mark Rutland wrote: >>> On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: > On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: >> This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface >> and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to >> PPMU >> counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC >> provides >> PPMU counters for DMC(Dynamic Memory Controller) to check memory bus >> utilization >> and then busfreq driver adjusts dynamically the operating >> frequency/voltage >> by using DEVFREQ Subsystem. >> >> Signed-off-by: Chanwoo Choi >> --- >> .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 >> ++ >> 1 file changed, 49 insertions(+) >> create mode 100644 >> Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> >> diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> new file mode 100644 >> index 000..2a83fcc >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> @@ -0,0 +1,49 @@ >> + >> +Exynos4210/4x12 busfreq driver >> +- >> + >> +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus >> frequency/voltage >> +scaling according to PPMU counters of memory controllers >> + >> +Required properties: >> +- compatible: should contain Exynos4 SoC type as follwoing: >> + - "samsung,exynos4x12-busfreq" for Exynos4x12 >> + - "samsung,exynos4210-busfreq" for Exynos4210 > > Is there a device called "busfreq"? What device does this binding > describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). >>> >>> This still sounds like a description of the _driver_, not the _device_. >>> The binding should describe the hardware, now the high level abstraction >>> that software is going to build atop of it. >>> >>> It sounds like this is a binding for the DMC PPMU? >>> >>> Is the PPMU a component of the DMC, or is it bolted on the side? >> >> PPMU(Performance Profiling Monitoring Unit) is to profile performance event >> of >> various IP on Exynos4. Each PPMU provide perforamnce event for each IP. >> We can check various PPMU as following: >> >> PPMU_3D >> PPMU_ACP >> PPMU_CAMIF >> PPMU_CPU >> PPMU_DMC0 >> PPMU_DMC1 >> PPMU_FSYS >> PPMU_IMAGE >> PPMU_LCD0 >> PPMU_LCD1 >> PPMU_MFC_L >> PPMU_MFC_R >> PPMU_TV >> PPMU_LEFT_BUS >> PPMU_RIGHT_BUS >> >> DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 SoC. >> If we need to get memory bust utilization of DMC, we can get memory bus >> utilization >> from PPMU_DMC0/PPMU_DMC1. >> >> So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various PPMU >> list. > > Well, PPMUs and DMCs are separate hardware blocks found inside Exynos SoCs. > Busfreq/devfreq is just a Linux-specific abstraction responsible for > collecting data using PPMUs and controlling frequencies and voltages of > appropriate power planes, vdd_int responsible for powering DMC0 and DMC1 > blocks in this case. > I knew already. > I'm afraid that the binding you're proposing is unfortunately incorrect, > because it represents the software abstraction, not the real hardware. What is exactly incorrect part of this patch? > > Instead, this should be separated into several independent bindings: > > - PPMU bindings to list all the PPMU instances present in the SoC and > resources they need, > > - power plane bindings, which define a power plane in which multiple IP > blocks might reside, can be monitored by one or more PPMU units and frequency > and voltage of which can be configured according to determined performance > level. Needed resources will be clocks and regulators to scale and probably > also operating points. > > Then, exynos-busfreq driver should bind to such power planes, parse necessary > data from DT (list of PPMUs and IP blocks, clocks, regulators and operating > points) and register a devfreq entity. What is 'power plane'? I don't know 'power plane'. If you suggest 'power plane' concept and then merge this concept to mainline, After merged 'power plane' concept, I will apply 'power plane' concept to Exynos4's b
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
On 15.03.2014 12:36, Kyungmin Park wrote: On Sat, Mar 15, 2014 at 2:35 AM, Tomasz Figa wrote: Hi Chanwoo, Mark, On 14.03.2014 11:56, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 07:35 PM, Mark Rutland wrote: On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization and then busfreq driver adjusts dynamically the operating frequency/voltage by using DEVFREQ Subsystem. Signed-off-by: Chanwoo Choi --- .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 ++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt new file mode 100644 index 000..2a83fcc --- /dev/null +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt @@ -0,0 +1,49 @@ + +Exynos4210/4x12 busfreq driver +- + +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage +scaling according to PPMU counters of memory controllers + +Required properties: +- compatible : should contain Exynos4 SoC type as follwoing: + - "samsung,exynos4x12-busfreq" for Exynos4x12 + - "samsung,exynos4210-busfreq" for Exynos4210 Is there a device called "busfreq"? What device does this binding describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). This still sounds like a description of the _driver_, not the _device_. The binding should describe the hardware, now the high level abstraction that software is going to build atop of it. It sounds like this is a binding for the DMC PPMU? Is the PPMU a component of the DMC, or is it bolted on the side? PPMU(Performance Profiling Monitoring Unit) is to profile performance event of various IP on Exynos4. Each PPMU provide perforamnce event for each IP. We can check various PPMU as following: PPMU_3D PPMU_ACP PPMU_CAMIF PPMU_CPU PPMU_DMC0 PPMU_DMC1 PPMU_FSYS PPMU_IMAGE PPMU_LCD0 PPMU_LCD1 PPMU_MFC_L PPMU_MFC_R PPMU_TV PPMU_LEFT_BUS PPMU_RIGHT_BUS DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 SoC. If we need to get memory bust utilization of DMC, we can get memory bus utilization from PPMU_DMC0/PPMU_DMC1. So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various PPMU list. Well, PPMUs and DMCs are separate hardware blocks found inside Exynos SoCs. Busfreq/devfreq is just a Linux-specific abstraction responsible for collecting data using PPMUs and controlling frequencies and voltages of appropriate power planes, vdd_int responsible for powering DMC0 and DMC1 blocks in this case. I'm afraid that the binding you're proposing is unfortunately incorrect, because it represents the software abstraction, not the real hardware. Instead, this should be separated into several independent bindings: - PPMU bindings to list all the PPMU instances present in the SoC and resources they need, - power plane bindings, which define a power plane in which multiple IP blocks might reside, can be monitored by one or more PPMU units and frequency and voltage of which can be configured according to determined performance level. Needed resources will be clocks and regulators to scale and probably also operating points. Then, exynos-busfreq driver should bind to such power planes, parse necessary data from DT (list of PPMUs and IP blocks, clocks, regulators and operating points) and register a devfreq entity. How about to use component DT like DRM? Well, basically this is what I proposed. Each "power plane" would be a "subsystem" built from components - PPMUs, IP blocks, clocks, regulators, etc, specified in DT by existing means, e.g. ppmu_disp: ppmu@1234 { /* Resources of PPMU */ } fimd: fimd@2345 { /* Resources of FIMD */ }; power-plane-display { compatible = "samsung,power-plane"; samsung,ppmus = <&ppmu_disp>, ...; samsung,devices = <&fimd>, ...; clock-names = "aclk_xxx", "sclk_xxx", ...; clocks = ...; vdd_xxx-supply = ...; }; However I'm still wondering whether there shouldn't be a relation between power planes and power domains and simply existing power d
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
On Sat, Mar 15, 2014 at 2:35 AM, Tomasz Figa wrote: > Hi Chanwoo, Mark, > > > On 14.03.2014 11:56, Chanwoo Choi wrote: >> >> Hi Mark, >> >> On 03/14/2014 07:35 PM, Mark Rutland wrote: >>> >>> On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: > > On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: >> >> This patch add busfreq driver for Exynos4210/Exynos4x12 memory >> interface >> and bus to support DVFS(Dynamic Voltage Frequency Scaling) according >> to PPMU >> counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 >> SoC provides >> PPMU counters for DMC(Dynamic Memory Controller) to check memory bus >> utilization >> and then busfreq driver adjusts dynamically the operating >> frequency/voltage >> by using DEVFREQ Subsystem. >> >> Signed-off-by: Chanwoo Choi >> --- >> .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 >> ++ >> 1 file changed, 49 insertions(+) >> create mode 100644 >> Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> >> diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> new file mode 100644 >> index 000..2a83fcc >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> @@ -0,0 +1,49 @@ >> + >> +Exynos4210/4x12 busfreq driver >> +- >> + >> +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus >> frequency/voltage >> +scaling according to PPMU counters of memory controllers >> + >> +Required properties: >> +- compatible : should contain Exynos4 SoC type as follwoing: >> + - "samsung,exynos4x12-busfreq" for Exynos4x12 >> + - "samsung,exynos4210-busfreq" for Exynos4210 > > > Is there a device called "busfreq"? What device does this binding > describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). >>> >>> >>> This still sounds like a description of the _driver_, not the _device_. >>> The binding should describe the hardware, now the high level abstraction >>> that software is going to build atop of it. >>> >>> It sounds like this is a binding for the DMC PPMU? >>> >>> Is the PPMU a component of the DMC, or is it bolted on the side? >> >> >> PPMU(Performance Profiling Monitoring Unit) is to profile performance >> event of >> various IP on Exynos4. Each PPMU provide perforamnce event for each IP. >> We can check various PPMU as following: >> >> PPMU_3D >> PPMU_ACP >> PPMU_CAMIF >> PPMU_CPU >> PPMU_DMC0 >> PPMU_DMC1 >> PPMU_FSYS >> PPMU_IMAGE >> PPMU_LCD0 >> PPMU_LCD1 >> PPMU_MFC_L >> PPMU_MFC_R >> PPMU_TV >> PPMU_LEFT_BUS >> PPMU_RIGHT_BUS >> >> DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 >> SoC. >> If we need to get memory bust utilization of DMC, we can get memory bus >> utilization >> from PPMU_DMC0/PPMU_DMC1. >> >> So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various >> PPMU list. > > > Well, PPMUs and DMCs are separate hardware blocks found inside Exynos SoCs. > Busfreq/devfreq is just a Linux-specific abstraction responsible for > collecting data using PPMUs and controlling frequencies and voltages of > appropriate power planes, vdd_int responsible for powering DMC0 and DMC1 > blocks in this case. > > I'm afraid that the binding you're proposing is unfortunately incorrect, > because it represents the software abstraction, not the real hardware. > > Instead, this should be separated into several independent bindings: > > - PPMU bindings to list all the PPMU instances present in the SoC and > resources they need, > > - power plane bindings, which define a power plane in which multiple IP > blocks might reside, can be monitored by one or more PPMU units and > frequency and voltage of which can be configured according to determined > performance level. Needed resources will be clocks and regulators to scale > and probably also operating points. > > Then, exynos-busfreq driver should bind to such power planes, parse > necessary data from DT (list of PPMUs and IP blocks, clocks, regulators and > operating points) and register a devfreq entity. How about to use component DT like DRM? > > Best regards, > Tomasz > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vge
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
Hi Chanwoo, Mark, On 14.03.2014 11:56, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 07:35 PM, Mark Rutland wrote: On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization and then busfreq driver adjusts dynamically the operating frequency/voltage by using DEVFREQ Subsystem. Signed-off-by: Chanwoo Choi --- .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 ++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt new file mode 100644 index 000..2a83fcc --- /dev/null +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt @@ -0,0 +1,49 @@ + +Exynos4210/4x12 busfreq driver +- + +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage +scaling according to PPMU counters of memory controllers + +Required properties: +- compatible : should contain Exynos4 SoC type as follwoing: + - "samsung,exynos4x12-busfreq" for Exynos4x12 + - "samsung,exynos4210-busfreq" for Exynos4210 Is there a device called "busfreq"? What device does this binding describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). This still sounds like a description of the _driver_, not the _device_. The binding should describe the hardware, now the high level abstraction that software is going to build atop of it. It sounds like this is a binding for the DMC PPMU? Is the PPMU a component of the DMC, or is it bolted on the side? PPMU(Performance Profiling Monitoring Unit) is to profile performance event of various IP on Exynos4. Each PPMU provide perforamnce event for each IP. We can check various PPMU as following: PPMU_3D PPMU_ACP PPMU_CAMIF PPMU_CPU PPMU_DMC0 PPMU_DMC1 PPMU_FSYS PPMU_IMAGE PPMU_LCD0 PPMU_LCD1 PPMU_MFC_L PPMU_MFC_R PPMU_TV PPMU_LEFT_BUS PPMU_RIGHT_BUS DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 SoC. If we need to get memory bust utilization of DMC, we can get memory bus utilization from PPMU_DMC0/PPMU_DMC1. So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various PPMU list. Well, PPMUs and DMCs are separate hardware blocks found inside Exynos SoCs. Busfreq/devfreq is just a Linux-specific abstraction responsible for collecting data using PPMUs and controlling frequencies and voltages of appropriate power planes, vdd_int responsible for powering DMC0 and DMC1 blocks in this case. I'm afraid that the binding you're proposing is unfortunately incorrect, because it represents the software abstraction, not the real hardware. Instead, this should be separated into several independent bindings: - PPMU bindings to list all the PPMU instances present in the SoC and resources they need, - power plane bindings, which define a power plane in which multiple IP blocks might reside, can be monitored by one or more PPMU units and frequency and voltage of which can be configured according to determined performance level. Needed resources will be clocks and regulators to scale and probably also operating points. Then, exynos-busfreq driver should bind to such power planes, parse necessary data from DT (list of PPMUs and IP blocks, clocks, regulators and operating points) and register a devfreq entity. Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
Hi Mark, On 03/14/2014 07:35 PM, Mark Rutland wrote: > On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: >> Hi Mark, >> >> On 03/14/2014 02:53 AM, Mark Rutland wrote: >>> On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC provides PPMU counters for DMC(Dynamic Memory Controller) to check memory bus utilization and then busfreq driver adjusts dynamically the operating frequency/voltage by using DEVFREQ Subsystem. Signed-off-by: Chanwoo Choi --- .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 ++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt new file mode 100644 index 000..2a83fcc --- /dev/null +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt @@ -0,0 +1,49 @@ + +Exynos4210/4x12 busfreq driver +- + +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus frequency/voltage +scaling according to PPMU counters of memory controllers + +Required properties: +- compatible : should contain Exynos4 SoC type as follwoing: +- "samsung,exynos4x12-busfreq" for Exynos4x12 +- "samsung,exynos4210-busfreq" for Exynos4210 >>> >>> Is there a device called "busfreq"? What device does this binding >>> describe? >> >> I'll add detailed description of busfreq as following: >> >> "busfreq(bus frequendcy)" driver means that busfreq driver control >> dynamically >> memory bus frequency/voltage by checking memory bus utilization to optimize >> power-consumption. When checking memeory bus utilization, exynos4_busfreq >> driver >> would use PPMU(Performance Profiling Monitoring Units). > > This still sounds like a description of the _driver_, not the _device_. > The binding should describe the hardware, now the high level abstraction > that software is going to build atop of it. > > It sounds like this is a binding for the DMC PPMU? > > Is the PPMU a component of the DMC, or is it bolted on the side? PPMU(Performance Profiling Monitoring Unit) is to profile performance event of various IP on Exynos4. Each PPMU provide perforamnce event for each IP. We can check various PPMU as following: PPMU_3D PPMU_ACP PPMU_CAMIF PPMU_CPU PPMU_DMC0 PPMU_DMC1 PPMU_FSYS PPMU_IMAGE PPMU_LCD0 PPMU_LCD1 PPMU_MFC_L PPMU_MFC_R PPMU_TV PPMU_LEFT_BUS PPMU_RIGHT_BUS DMC (Dynamic Memory Controller) control the operation of DRAM in Exynos4 SoC. If we need to get memory bust utilization of DMC, we can get memory bus utilization from PPMU_DMC0/PPMU_DMC1. So, Exynos4's busfreq used two(PPMU_DMC0/PPMU_DMC1) among upper various PPMU list. > >> >> >>> +- reg : offset and length of the ppmudmc0/1 +- PPMU (Performance Profiling Monitoring Units) >>> >>> You seem to require a particular order here. It would be good to be >>> explicit about it. >> >> OK, I'll modify it as following: >> the offset and length of the PPMU_DMC0 / PPMU_DMC1 >> PPMU_DMC0/PPMU_DMC1 show memory buy utilization to exynos4_bus driver. >> >>> +: It is to profile performance event of DMC(Dynamic Memory +Controller) So, exynos4_bus.c can check memory bus utilization +by using PPMU of Exynos4 SoC. >>> >>> This is superfluous, and Linux-specific. The binding document shouldn't >>> need to refer to drivers. >> >> I'll remove this description. >> >>> +- clocks : clock number of ppmudmc0/1 +- clock-names : clock name of ppmudmc0/1 >>> >>> Are these two clocks, or one clock with a slash in the name? >>> >>> Please list each name separately. >> >> I'll expalin clocks as following: >> "ppmudmc0", "ppmudmc1" >> >>> +- vdd_int-supply: regulator for interface block of Exynos4 > > How does the interface block relate to the DMC / PPMU? If vdd_int is connected to buck3 of PMIC(Power Management IC), We can see the flow of provided power as following: : external power --> buck3 pin of PMIC --> vdd_int pin of Exynos4 SoC --> DMC IP and PPMU IP of Exynos4 SoC Thanks, Chanwoo Choi -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
On Fri, Mar 14, 2014 at 07:14:37AM +, Chanwoo Choi wrote: > Hi Mark, > > On 03/14/2014 02:53 AM, Mark Rutland wrote: > > On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: > >> This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface > >> and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to > >> PPMU > >> counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC > >> provides > >> PPMU counters for DMC(Dynamic Memory Controller) to check memory bus > >> utilization > >> and then busfreq driver adjusts dynamically the operating frequency/voltage > >> by using DEVFREQ Subsystem. > >> > >> Signed-off-by: Chanwoo Choi > >> --- > >> .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 > >> ++ > >> 1 file changed, 49 insertions(+) > >> create mode 100644 > >> Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > >> > >> diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > >> b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > >> new file mode 100644 > >> index 000..2a83fcc > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > >> @@ -0,0 +1,49 @@ > >> + > >> +Exynos4210/4x12 busfreq driver > >> +- > >> + > >> +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus > >> frequency/voltage > >> +scaling according to PPMU counters of memory controllers > >> + > >> +Required properties: > >> +- compatible : should contain Exynos4 SoC type as follwoing: > >> +- "samsung,exynos4x12-busfreq" for Exynos4x12 > >> +- "samsung,exynos4210-busfreq" for Exynos4210 > > > > Is there a device called "busfreq"? What device does this binding > > describe? > > I'll add detailed description of busfreq as following: > > "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically > memory bus frequency/voltage by checking memory bus utilization to optimize > power-consumption. When checking memeory bus utilization, exynos4_busfreq > driver > would use PPMU(Performance Profiling Monitoring Units). This still sounds like a description of the _driver_, not the _device_. The binding should describe the hardware, now the high level abstraction that software is going to build atop of it. It sounds like this is a binding for the DMC PPMU? Is the PPMU a component of the DMC, or is it bolted on the side? > > > > > >> +- reg : offset and length of the ppmudmc0/1 > >> +- PPMU (Performance Profiling Monitoring Units) > > > > You seem to require a particular order here. It would be good to be > > explicit about it. > > OK, I'll modify it as following: > the offset and length of the PPMU_DMC0 / PPMU_DMC1 > PPMU_DMC0/PPMU_DMC1 show memory buy utilization to exynos4_bus driver. > > > > >> +: It is to profile performance event of DMC(Dynamic Memory > >> +Controller) So, exynos4_bus.c can check memory bus utilization > >> +by using PPMU of Exynos4 SoC. > > > > This is superfluous, and Linux-specific. The binding document shouldn't > > need to refer to drivers. > > I'll remove this description. > > > > >> +- clocks : clock number of ppmudmc0/1 > >> +- clock-names : clock name of ppmudmc0/1 > > > > Are these two clocks, or one clock with a slash in the name? > > > > Please list each name separately. > > I'll expalin clocks as following: > "ppmudmc0", "ppmudmc1" > > > > >> +- vdd_int-supply: regulator for interface block of Exynos4 How does the interface block relate to the DMC / PPMU? Cheers, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
Hi Mark, On 03/14/2014 02:53 AM, Mark Rutland wrote: > On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: >> This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface >> and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU >> counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC >> provides >> PPMU counters for DMC(Dynamic Memory Controller) to check memory bus >> utilization >> and then busfreq driver adjusts dynamically the operating frequency/voltage >> by using DEVFREQ Subsystem. >> >> Signed-off-by: Chanwoo Choi >> --- >> .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 >> ++ >> 1 file changed, 49 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> >> diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> new file mode 100644 >> index 000..2a83fcc >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt >> @@ -0,0 +1,49 @@ >> + >> +Exynos4210/4x12 busfreq driver >> +- >> + >> +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus >> frequency/voltage >> +scaling according to PPMU counters of memory controllers >> + >> +Required properties: >> +- compatible: should contain Exynos4 SoC type as follwoing: >> + - "samsung,exynos4x12-busfreq" for Exynos4x12 >> + - "samsung,exynos4210-busfreq" for Exynos4210 > > Is there a device called "busfreq"? What device does this binding > describe? I'll add detailed description of busfreq as following: "busfreq(bus frequendcy)" driver means that busfreq driver control dynamically memory bus frequency/voltage by checking memory bus utilization to optimize power-consumption. When checking memeory bus utilization, exynos4_busfreq driver would use PPMU(Performance Profiling Monitoring Units). > >> +- reg : offset and length of the ppmudmc0/1 >> + - PPMU (Performance Profiling Monitoring Units) > > You seem to require a particular order here. It would be good to be > explicit about it. OK, I'll modify it as following: the offset and length of the PPMU_DMC0 / PPMU_DMC1 PPMU_DMC0/PPMU_DMC1 show memory buy utilization to exynos4_bus driver. > >> + : It is to profile performance event of DMC(Dynamic Memory >> + Controller) So, exynos4_bus.c can check memory bus utilization >> + by using PPMU of Exynos4 SoC. > > This is superfluous, and Linux-specific. The binding document shouldn't > need to refer to drivers. I'll remove this description. > >> +- clocks: clock number of ppmudmc0/1 >> +- clock-names : clock name of ppmudmc0/1 > > Are these two clocks, or one clock with a slash in the name? > > Please list each name separately. I'll expalin clocks as following: "ppmudmc0", "ppmudmc1" > >> +- vdd_int-supply: regulator for interface block of Exynos4 >> + >> +Optional properties: >> +- vdd_mif-supply: regulator for DMC block of Exynos4x12 if Exynos4x12 Soc >> +- regs-name : register name of ppmudmc0/1 > > This is completely nonstandard. Did you mean reg-names? I'll remove it about 'regs-name'. > > Please be explicit about the names you expect. Write them in full, > quoted, and describe the relationship to the reg property. > >> + >> +All the required listed above must be defined under code busfreq with >> devfreq > > I'm having some difficulty figuring out what exactly this is intended to > mean. I'll add detailed opeation method and role of exynos4_busfreq driver. Thanks, Chanwoo Choi -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
On Thu, Mar 13, 2014 at 08:17:29AM +, Chanwoo Choi wrote: > This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface > and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU > counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC > provides > PPMU counters for DMC(Dynamic Memory Controller) to check memory bus > utilization > and then busfreq driver adjusts dynamically the operating frequency/voltage > by using DEVFREQ Subsystem. > > Signed-off-by: Chanwoo Choi > --- > .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 > ++ > 1 file changed, 49 insertions(+) > create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > > diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > new file mode 100644 > index 000..2a83fcc > --- /dev/null > +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > @@ -0,0 +1,49 @@ > + > +Exynos4210/4x12 busfreq driver > +- > + > +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus > frequency/voltage > +scaling according to PPMU counters of memory controllers > + > +Required properties: > +- compatible : should contain Exynos4 SoC type as follwoing: > + - "samsung,exynos4x12-busfreq" for Exynos4x12 > + - "samsung,exynos4210-busfreq" for Exynos4210 Is there a device called "busfreq"? What device does this binding describe? > +- reg: offset and length of the ppmudmc0/1 > + - PPMU (Performance Profiling Monitoring Units) You seem to require a particular order here. It would be good to be explicit about it. > + : It is to profile performance event of DMC(Dynamic Memory > + Controller) So, exynos4_bus.c can check memory bus utilization > + by using PPMU of Exynos4 SoC. This is superfluous, and Linux-specific. The binding document shouldn't need to refer to drivers. > +- clocks : clock number of ppmudmc0/1 > +- clock-names: clock name of ppmudmc0/1 Are these two clocks, or one clock with a slash in the name? Please list each name separately. > +- vdd_int-supply: regulator for interface block of Exynos4 > + > +Optional properties: > +- vdd_mif-supply: regulator for DMC block of Exynos4x12 if Exynos4x12 Soc > +- regs-name : register name of ppmudmc0/1 This is completely nonstandard. Did you mean reg-names? Please be explicit about the names you expect. Write them in full, quoted, and describe the relationship to the reg property. > + > +All the required listed above must be defined under code busfreq with devfreq I'm having some difficulty figuring out what exactly this is intended to mean. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCHv2 8/8] devfreq: exynos4: Add busfreq driver for exynos4210/exynos4x12
On Thursday, March 13, 2014 05:17:29 PM Chanwoo Choi wrote: > This patch add busfreq driver for Exynos4210/Exynos4x12 memory interface This patch adds DT binding documentation not the driver itself. Same comment for the patch summary line. > and bus to support DVFS(Dynamic Voltage Frequency Scaling) according to PPMU > counters. PPMU (Performance Profiling Monitorings Units) of Exynos4 SoC > provides > PPMU counters for DMC(Dynamic Memory Controller) to check memory bus > utilization > and then busfreq driver adjusts dynamically the operating frequency/voltage > by using DEVFREQ Subsystem. > > Signed-off-by: Chanwoo Choi > --- > .../devicetree/bindings/devfreq/exynos4_bus.txt| 49 > ++ > 1 file changed, 49 insertions(+) > create mode 100644 Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > > diff --git a/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > new file mode 100644 > index 000..2a83fcc > --- /dev/null > +++ b/Documentation/devicetree/bindings/devfreq/exynos4_bus.txt > @@ -0,0 +1,49 @@ > + > +Exynos4210/4x12 busfreq driver > +- > + > +Exynos4210/4x12 Soc busfreq driver with devfreq for Memory bus > frequency/voltage SoC > +scaling according to PPMU counters of memory controllers > + > +Required properties: > +- compatible : should contain Exynos4 SoC type as follwoing: following > + - "samsung,exynos4x12-busfreq" for Exynos4x12 > + - "samsung,exynos4210-busfreq" for Exynos4210 > +- reg: offset and length of the ppmudmc0/1 > + - PPMU (Performance Profiling Monitoring Units) > + : It is to profile performance event of DMC(Dynamic Memory > + Controller) So, exynos4_bus.c can check memory bus utilization > + by using PPMU of Exynos4 SoC. It can be improved by changing ordering, i.e. : PPMU of Exynos4 SoC is used to profile performance event of DMC (Dynamic Memory Controller) so the driver can check memory bus utilization. > +- clocks : clock number of ppmudmc0/1 > +- clock-names: clock name of ppmudmc0/1 > +- vdd_int-supply: regulator for interface block of Exynos4 > + > +Optional properties: > +- vdd_mif-supply: regulator for DMC block of Exynos4x12 if Exynos4x12 Soc if using Exynos4x12 SoC > +- regs-name : register name of ppmudmc0/1 > + > +All the required listed above must be defined under code busfreq with devfreq required properties > +Exmaple: Example: > +For Exynos4210 busfreq, please add a newline here > + busfreq@106A { > + compatible = "samsung,exynos4210-busfreq"; > + reg = <0x106A 0x2000>, <0x106B 0x2000>; > + regs-name = "PPMU_DMC0", "PPMU_DMC1"; > + clocks = <&clock CLK_PPMUDMC0>, <&clock CLK_PPMUDMC1>; > + clock-names = "ppmudmc0", "ppmudmc1"; > + > + vdd_int-supply = <&buck3_reg>; > + }; > + > +For Exynos4x12 busfreq, ditto > + busfreq@106A { > + compatible = "samsung,exynos4x12-busfreq"; > + reg = <0x106A 0x2000>, <0x106B 0x2000>; > + regs-name = "PPMU_DMC0", "PPMU_DMC1"; > + clocks = <&clock CLK_PPMUDMC0>, <&clock CLK_PPMUDMC1>; > + clock-names = "ppmudmc0", "ppmudmc1"; > + > + vdd_mif-suppy = <&buck1_reg>; > + vdd_int-supply = <&buck3_reg>; > + }; Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html