| Message ID | 20160622091555.18415-1-maxime.ripard@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Maxime, We need a path to set CLK_SET_RATE_PARENT any other needed flags when a fixed-factor-clock is initialized by DT. It seems your way will work also for my case. However, I suggested some more generic approach: https://lkml.org/lkml/2016/6/24/3 Please leave any comments. On 2016년 06월 22일 18:15, Maxime Ripard wrote: > The only way for a fixed factor clock to change its rate would be to change > its parent rate. > > Since passing blindly CLK_SET_RATE_PARENT might break a lot of platforms > that were relying on the fact that the parent rate wouldn't change, > introduce a compatible-based whitelist that will allow clocks to opt-in > that flag. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > --- > .../devicetree/bindings/clock/fixed-factor-clock.txt | 4 ++++ > drivers/clk/clk-fixed-factor.c | 11 ++++++++++- > 2 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt b/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt > index 1bae8527eb9b..189467a7188a 100644 > --- a/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt > +++ b/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt > @@ -14,6 +14,10 @@ Required properties: > Optional properties: > - clock-output-names : From common clock binding. > > +Some clocks that require special treatments are also handled by that > +driver, with the compatibles: > + - allwinner,sun4i-a10-pll3-2x-clk > + > Example: > clock { > compatible = "fixed-factor-clock"; > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c > index 75cd6c792cb8..4db3be214077 100644 > --- a/drivers/clk/clk-fixed-factor.c > +++ b/drivers/clk/clk-fixed-factor.c > @@ -142,6 +142,11 @@ void clk_hw_unregister_fixed_factor(struct clk_hw *hw) > EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor); > > #ifdef CONFIG_OF > +static const struct of_device_id set_rate_parent_matches[] = { > + { .compatible = "allwinner,sun4i-a10-pll3-2x-clk" }, > + { /* Sentinel */ }, > +}; > + > /** > * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock > */ > @@ -150,6 +155,7 @@ void __init of_fixed_factor_clk_setup(struct device_node *node) > struct clk *clk; > const char *clk_name = node->name; > const char *parent_name; > + unsigned long flags = 0; > u32 div, mult; > > if (of_property_read_u32(node, "clock-div", &div)) { > @@ -167,7 +173,10 @@ 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); > > - clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0, > + if (of_match_node(set_rate_parent_matches, node)) > + flags |= CLK_SET_RATE_PARENT; > + > + 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);
On Wed, Jun 22, 2016 at 11:15:54AM +0200, Maxime Ripard wrote: > The only way for a fixed factor clock to change its rate would be to change > its parent rate. > > Since passing blindly CLK_SET_RATE_PARENT might break a lot of platforms > that were relying on the fact that the parent rate wouldn't change, > introduce a compatible-based whitelist that will allow clocks to opt-in > that flag. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > --- > .../devicetree/bindings/clock/fixed-factor-clock.txt | 4 ++++ I don't think we should be copying clk flags to DT as suggested. Acked-by: Rob Herring <robh@kernel.org> > drivers/clk/clk-fixed-factor.c | 11 ++++++++++- > 2 files changed, 14 insertions(+), 1 deletion(-)
On 06/22, Maxime Ripard wrote: > The only way for a fixed factor clock to change its rate would be to change > its parent rate. > > Since passing blindly CLK_SET_RATE_PARENT might break a lot of platforms > that were relying on the fact that the parent rate wouldn't change, > introduce a compatible-based whitelist that will allow clocks to opt-in > that flag. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > --- Applied to clk-next
diff --git a/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt b/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt index 1bae8527eb9b..189467a7188a 100644 --- a/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt +++ b/Documentation/devicetree/bindings/clock/fixed-factor-clock.txt @@ -14,6 +14,10 @@ Required properties: Optional properties: - clock-output-names : From common clock binding. +Some clocks that require special treatments are also handled by that +driver, with the compatibles: + - allwinner,sun4i-a10-pll3-2x-clk + Example: clock { compatible = "fixed-factor-clock"; diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c index 75cd6c792cb8..4db3be214077 100644 --- a/drivers/clk/clk-fixed-factor.c +++ b/drivers/clk/clk-fixed-factor.c @@ -142,6 +142,11 @@ void clk_hw_unregister_fixed_factor(struct clk_hw *hw) EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor); #ifdef CONFIG_OF +static const struct of_device_id set_rate_parent_matches[] = { + { .compatible = "allwinner,sun4i-a10-pll3-2x-clk" }, + { /* Sentinel */ }, +}; + /** * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock */ @@ -150,6 +155,7 @@ void __init of_fixed_factor_clk_setup(struct device_node *node) struct clk *clk; const char *clk_name = node->name; const char *parent_name; + unsigned long flags = 0; u32 div, mult; if (of_property_read_u32(node, "clock-div", &div)) { @@ -167,7 +173,10 @@ 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); - clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0, + if (of_match_node(set_rate_parent_matches, node)) + flags |= CLK_SET_RATE_PARENT; + + 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);
The only way for a fixed factor clock to change its rate would be to change its parent rate. Since passing blindly CLK_SET_RATE_PARENT might break a lot of platforms that were relying on the fact that the parent rate wouldn't change, introduce a compatible-based whitelist that will allow clocks to opt-in that flag. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> --- .../devicetree/bindings/clock/fixed-factor-clock.txt | 4 ++++ drivers/clk/clk-fixed-factor.c | 11 ++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-)