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 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 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
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
[PATCH v2] clk: fixed-factor: add optional dt-binding clock-flags
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.
[1] http://www.spinics.net/lists/linux-clk/msg09040.html
[2] https://lkml.org/lkml/2016/6/20/1025
Changes since v1:
- fix possible build failure when using gcc-5 or gcc-6
Signed-off-by: Jongsung Kim
Cc: Maxime Ripard
Cc: Mike Turquette
Cc: Stephen Boyd
---
.../bindings/clock/fixed-factor-clock.txt | 4
drivers/clk/clk-fixed-factor.c | 4 +++-
include/dt-bindings/clk/clk.h | 22 ++
3 files changed, 29 insertions(+), 1 deletion(-)
create mode 100644 include/dt-bindings/clk/clk.h
diff --git a/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt
b/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt
index 1bae8527..3e1b79e 100644
--- a/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt
+++ b/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt
@@ -13,12 +13,16 @@ Required properties:
Optional properties:
- clock-output-names : From common clock binding.
+- clock-flags : Additional flags to be used.
Example:
+ #include
+
clock {
compatible = "fixed-factor-clock";
clocks = <&parentclk>;
#clock-cells = <0>;
clock-div = <2>;
clock-mult = <1>;
+ clock-flags = ;
};
diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index 75cd6c7..e626cad 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -150,6 +150,7 @@ void __init of_fixed_factor_clk_setup(struct device_node
*node)
struct clk *clk;
const char *clk_name = node->name;
const char *parent_name;
+ u32 flags = 0;
u32 div, mult;
if (of_property_read_u32(node, "clock-div", &div)) {
@@ -166,8 +167,9 @@ void __init of_fixed_factor_clk_setup(struct device_node
*node)
of_property_read_string(node, "clock-output-names", &clk_name);
parent_name = of_clk_get_parent_name(node, 0);
+ of_property_read_u32(node, "clock-flags", &flags);
- clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
+ clk = clk_register_fixed_factor(NULL, clk_name, parent_name, flags,
mult, div);
if (!IS_ERR(clk))
of_clk_add_provider(node, of_clk_src_simple_get, clk);
diff --git a/include/dt-bindings/clk/clk.h b/include/dt-bindings/clk/clk.h
new file mode 100644
index 000..1834933
--- /dev/null
+++ b/include/dt-bindings/clk/clk.h
@@ -0,0 +1,22 @@
+/*
+ * See include/linux/clk-provider.h for more information.
+ */
+
+#ifndef __DT_BINDINGS_CLK_CLK_H
+#define __DT_BINDINGS_CLK_CLK_H
+
+#define BIT(nr)(1UL << (nr))
+
+#define CLK_SET_RATE_GATE BIT(0)
+#define CLK_SET_PARENT_GATEBIT(1)
+#define CLK_SET_RATE_PARENTBIT(2)
+#define CLK_IGNORE_UNUSED BIT(3)
+#define CLK_IS_BASIC BIT(5)
+#define CLK_GET_RATE_NOCACHE BIT(6)
+#define CLK_SET_RATE_NO_REPARENT BIT(7)
+#define CLK_GET_ACCURACY_NOCACHE BIT(8)
+#define CLK_RECALC_NEW_RATES BIT(9)
+#define CLK_SET_RATE_UNGATEBIT(10)
+#define CLK_IS_CRITICALBIT(11)
+
+#endif
--
2.7.4
