Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 07/04, Jongsung Kim wrote: > On 2016년 07월 02일 09:20, Stephen Boyd wrote: > > Do you actually have an IC on the board that is doing some fixed > > factor calculation? Or is this a clk driver design where we are > > listing out each piece of an SoC's clk controller in DT? > > > The SoC has several PLLs of identical design, and one of them is divided > to half and used for CPUs. The fixed-factor-clock represents the divider. > Ok, so it sounds like we can have the driver that registers the CPU PLL also register the fixed factor clk? I fail to see why we need this from DT in that case. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 07/04, Jongsung Kim wrote: > On 2016년 07월 02일 09:20, Stephen Boyd wrote: > > Do you actually have an IC on the board that is doing some fixed > > factor calculation? Or is this a clk driver design where we are > > listing out each piece of an SoC's clk controller in DT? > > > The SoC has several PLLs of identical design, and one of them is divided > to half and used for CPUs. The fixed-factor-clock represents the divider. > Ok, so it sounds like we can have the driver that registers the CPU PLL also register the fixed factor clk? I fail to see why we need this from DT in that case. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 2016년 07월 02일 09:20, Stephen Boyd wrote: > On 06/29, Jongsung Kim wrote: >> On 2016년 06월 29일 06:18, Michael Turquette wrote: >>> Quoting Rob Herring (2016-06-28 13:55:18) On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > There is no way to set additional flags for a DT-initialized fixed- > factor-clock, and it can be problematic i.e., when the clock rate > needs to be changed. [1][2] > > This patch introduces an optional dt-binding named "clock-flags" to > be used for passing any needed flags from dts. I don't think we want this in DT. If we did, the flags would need some documentation about what the flags mean. >>> Flags are specific to Linux implementation, so I agree with Rob. Better >>> to create a compatible string for your hardware that bakes in the flags. >> Thank you for your comment, Mike. This conversation starts from lacking >> method to set CLK_SET_RATE_PARENT from DT. I understand compatible string >> can be a solution. But.. if someone starts talking about lacking method to >> set another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another >> compatible string list. >> How do you think about defining possible required subset of the flags and >> using some more neutral flag-names acceptable in DT? > Do you actually have an IC on the board that is doing some fixed > factor calculation? Or is this a clk driver design where we are > listing out each piece of an SoC's clk controller in DT? > The SoC has several PLLs of identical design, and one of them is divided to half and used for CPUs. The fixed-factor-clock represents the divider.
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 2016년 07월 02일 09:20, Stephen Boyd wrote: > On 06/29, Jongsung Kim wrote: >> On 2016년 06월 29일 06:18, Michael Turquette wrote: >>> Quoting Rob Herring (2016-06-28 13:55:18) On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > There is no way to set additional flags for a DT-initialized fixed- > factor-clock, and it can be problematic i.e., when the clock rate > needs to be changed. [1][2] > > This patch introduces an optional dt-binding named "clock-flags" to > be used for passing any needed flags from dts. I don't think we want this in DT. If we did, the flags would need some documentation about what the flags mean. >>> Flags are specific to Linux implementation, so I agree with Rob. Better >>> to create a compatible string for your hardware that bakes in the flags. >> Thank you for your comment, Mike. This conversation starts from lacking >> method to set CLK_SET_RATE_PARENT from DT. I understand compatible string >> can be a solution. But.. if someone starts talking about lacking method to >> set another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another >> compatible string list. >> How do you think about defining possible required subset of the flags and >> using some more neutral flag-names acceptable in DT? > Do you actually have an IC on the board that is doing some fixed > factor calculation? Or is this a clk driver design where we are > listing out each piece of an SoC's clk controller in DT? > The SoC has several PLLs of identical design, and one of them is divided to half and used for CPUs. The fixed-factor-clock represents the divider.
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 06/29, Jongsung Kim wrote: > On 2016년 06월 29일 06:18, Michael Turquette wrote: > > Quoting Rob Herring (2016-06-28 13:55:18) > >> On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > >>> There is no way to set additional flags for a DT-initialized fixed- > >>> factor-clock, and it can be problematic i.e., when the clock rate > >>> needs to be changed. [1][2] > >>> > >>> This patch introduces an optional dt-binding named "clock-flags" to > >>> be used for passing any needed flags from dts. > >> I don't think we want this in DT. If we did, the flags would need some > >> documentation about what the flags mean. > > Flags are specific to Linux implementation, so I agree with Rob. Better > > to create a compatible string for your hardware that bakes in the flags. > > Thank you for your comment, Mike. This conversation starts from lacking > method to set CLK_SET_RATE_PARENT from DT. I understand compatible string can > be a solution. But.. if someone starts talking about lacking method to set > another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another compatible > string list. > How do you think about defining possible required subset of the flags and > using some more neutral flag-names acceptable in DT? Do you actually have an IC on the board that is doing some fixed factor calculation? Or is this a clk driver design where we are listing out each piece of an SoC's clk controller in DT? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 06/29, Jongsung Kim wrote: > On 2016년 06월 29일 06:18, Michael Turquette wrote: > > Quoting Rob Herring (2016-06-28 13:55:18) > >> On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > >>> There is no way to set additional flags for a DT-initialized fixed- > >>> factor-clock, and it can be problematic i.e., when the clock rate > >>> needs to be changed. [1][2] > >>> > >>> This patch introduces an optional dt-binding named "clock-flags" to > >>> be used for passing any needed flags from dts. > >> I don't think we want this in DT. If we did, the flags would need some > >> documentation about what the flags mean. > > Flags are specific to Linux implementation, so I agree with Rob. Better > > to create a compatible string for your hardware that bakes in the flags. > > Thank you for your comment, Mike. This conversation starts from lacking > method to set CLK_SET_RATE_PARENT from DT. I understand compatible string can > be a solution. But.. if someone starts talking about lacking method to set > another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another compatible > string list. > How do you think about defining possible required subset of the flags and > using some more neutral flag-names acceptable in DT? Do you actually have an IC on the board that is doing some fixed factor calculation? Or is this a clk driver design where we are listing out each piece of an SoC's clk controller in DT? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 2016년 06월 29일 06:18, Michael Turquette wrote: > Quoting Rob Herring (2016-06-28 13:55:18) >> On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: >>> There is no way to set additional flags for a DT-initialized fixed- >>> factor-clock, and it can be problematic i.e., when the clock rate >>> needs to be changed. [1][2] >>> >>> This patch introduces an optional dt-binding named "clock-flags" to >>> be used for passing any needed flags from dts. >> I don't think we want this in DT. If we did, the flags would need some >> documentation about what the flags mean. > Flags are specific to Linux implementation, so I agree with Rob. Better > to create a compatible string for your hardware that bakes in the flags. Thank you for your comment, Mike. This conversation starts from lacking method to set CLK_SET_RATE_PARENT from DT. I understand compatible string can be a solution. But.. if someone starts talking about lacking method to set another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another compatible string list. How do you think about defining possible required subset of the flags and using some more neutral flag-names acceptable in DT?
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 2016년 06월 29일 06:18, Michael Turquette wrote: > Quoting Rob Herring (2016-06-28 13:55:18) >> On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: >>> There is no way to set additional flags for a DT-initialized fixed- >>> factor-clock, and it can be problematic i.e., when the clock rate >>> needs to be changed. [1][2] >>> >>> This patch introduces an optional dt-binding named "clock-flags" to >>> be used for passing any needed flags from dts. >> I don't think we want this in DT. If we did, the flags would need some >> documentation about what the flags mean. > Flags are specific to Linux implementation, so I agree with Rob. Better > to create a compatible string for your hardware that bakes in the flags. Thank you for your comment, Mike. This conversation starts from lacking method to set CLK_SET_RATE_PARENT from DT. I understand compatible string can be a solution. But.. if someone starts talking about lacking method to set another flag, i.e., CLK_SET_PARENT_GATE, then we'll need another compatible string list. How do you think about defining possible required subset of the flags and using some more neutral flag-names acceptable in DT?
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 2016년 06월 29일 05:55, Rob Herring wrote: > On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: >> There is no way to set additional flags for a DT-initialized fixed- >> factor-clock, and it can be problematic i.e., when the clock rate >> needs to be changed. [1][2] >> >> This patch introduces an optional dt-binding named "clock-flags" to >> be used for passing any needed flags from dts. > I don't think we want this in DT. If we did, the flags would need some > documentation about what the flags mean. Thanks for your comment. It looks not that big deal to provide a little documentation..? Some of the flags looks safe to be removed. Thinking of only fixed-factor-clock, most of them can be removed.
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On 2016년 06월 29일 05:55, Rob Herring wrote: > On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: >> There is no way to set additional flags for a DT-initialized fixed- >> factor-clock, and it can be problematic i.e., when the clock rate >> needs to be changed. [1][2] >> >> This patch introduces an optional dt-binding named "clock-flags" to >> be used for passing any needed flags from dts. > I don't think we want this in DT. If we did, the flags would need some > documentation about what the flags mean. Thanks for your comment. It looks not that big deal to provide a little documentation..? Some of the flags looks safe to be removed. Thinking of only fixed-factor-clock, most of them can be removed.
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
Quoting Rob Herring (2016-06-28 13:55:18) > On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > > There is no way to set additional flags for a DT-initialized fixed- > > factor-clock, and it can be problematic i.e., when the clock rate > > needs to be changed. [1][2] > > > > This patch introduces an optional dt-binding named "clock-flags" to > > be used for passing any needed flags from dts. > > I don't think we want this in DT. If we did, the flags would need some > documentation about what the flags mean. Flags are specific to Linux implementation, so I agree with Rob. Better to create a compatible string for your hardware that bakes in the flags. Regards, Mike > > Rob
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
Quoting Rob Herring (2016-06-28 13:55:18) > On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > > There is no way to set additional flags for a DT-initialized fixed- > > factor-clock, and it can be problematic i.e., when the clock rate > > needs to be changed. [1][2] > > > > This patch introduces an optional dt-binding named "clock-flags" to > > be used for passing any needed flags from dts. > > I don't think we want this in DT. If we did, the flags would need some > documentation about what the flags mean. Flags are specific to Linux implementation, so I agree with Rob. Better to create a compatible string for your hardware that bakes in the flags. Regards, Mike > > Rob
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > There is no way to set additional flags for a DT-initialized fixed- > factor-clock, and it can be problematic i.e., when the clock rate > needs to be changed. [1][2] > > This patch introduces an optional dt-binding named "clock-flags" to > be used for passing any needed flags from dts. I don't think we want this in DT. If we did, the flags would need some documentation about what the flags mean. Rob
Re: [PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
On Fri, Jun 24, 2016 at 01:12:52PM +0900, Jongsung Kim wrote: > There is no way to set additional flags for a DT-initialized fixed- > factor-clock, and it can be problematic i.e., when the clock rate > needs to be changed. [1][2] > > This patch introduces an optional dt-binding named "clock-flags" to > be used for passing any needed flags from dts. I don't think we want this in DT. If we did, the flags would need some documentation about what the flags mean. Rob
