[PATCH 1/4] clk: propagate parent change up one level
Hi Mike,
Do you have any comments about this patch?
The patch is needed to provide a clean fix for recently
broken support for HDMI on Exynos4210 SoC in mainline.
Regards,
Tomasz Stanislawski
On 05/01/2014 12:19 AM, Tomasz Figa wrote:
> Mike,
>
> On 08.04.2014 17:45, Tomasz Figa wrote:
>> Hi,
>>
>> On 04.04.2014 16:53, Tomasz Stanislawski wrote:
>>> This patch adds support for propagation of setup of clock's parent one
>>> level
>>> up.
>>>
>>> This feature is helpful when a driver changes topology of its clocks
>>> using
>>> clk_set_parent(). The problem occurs when on one platform/SoC
>>> driver's clock
>>> is located at MUX output but on the other platform/SoC there is a
>>> gated proxy
>>> clock between the MUX and driver's clock. In such a case, driver's
>>> code has to
>>> be modified to use one clock for enabling and the other clock for
>>> setup of a
>>> parent.
>>>
>>> The code updates are avoided by propagating setup of a parent up one
>>> level.
>>>
>>> Additionally, this patch adds CLK_SET_PARENT_PARENT (sorry for naming)
>>> flag to
>>> inform clk-core that clk_set_parent() should be propagated.
>>>
>>> Signed-off-by: Tomasz Stanislawski
>>> ---
>>> drivers/clk/clk.c|6 ++
>>> include/linux/clk-provider.h |1 +
>>> 2 files changed, 7 insertions(+)
>>>
>>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>>> index dff0373..53bbfda 100644
>>> --- a/drivers/clk/clk.c
>>> +++ b/drivers/clk/clk.c
>>> @@ -1737,6 +1737,12 @@ int clk_set_parent(struct clk *clk, struct clk
>>> *parent)
>>>
>>> /* try finding the new parent index */
>>> if (parent) {
>>> +if ((clk->flags & CLK_SET_PARENT_PARENT)
>>> +&& clk->num_parents == 1) {
>>> +ret = clk_set_parent(clk->parent, parent);
>>> +goto out;
>>> +}
>>> +
>>> p_index = clk_fetch_parent_index(clk, parent);
>>> p_rate = parent->rate;
>>> if (p_index < 0) {
>>> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
>>> index 5119174..daa0b03 100644
>>> --- a/include/linux/clk-provider.h
>>> +++ b/include/linux/clk-provider.h
>>> @@ -30,6 +30,7 @@
>>> #define CLK_GET_RATE_NOCACHEBIT(6) /* do not use the cached clk
>>> rate */
>>> #define CLK_SET_RATE_NO_REPARENT BIT(7) /* don't re-parent on rate
>>> change */
>>> #define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk
>>> accuracy */
>>> +#define CLK_SET_PARENT_PARENTBIT(9) /* propagate parent change up
>>> one level */
>>>
>>> struct clk_hw;
>>> struct dentry;
>>>
>>
>> This would be very useful, at least on Exynos platforms, with
>> mux-div-gate clock paths. PARENT_PARENT sounds a bit funny, though.
>>
>> Reviewed-by: Tomasz Figa
>
> Your opinion on this would be greatly appreciated.
>
> Best regards,
> Tomasz
[PATCH 1/4] clk: propagate parent change up one level
Mike,
On 08.04.2014 17:45, Tomasz Figa wrote:
> Hi,
>
> On 04.04.2014 16:53, Tomasz Stanislawski wrote:
>> This patch adds support for propagation of setup of clock's parent one
>> level
>> up.
>>
>> This feature is helpful when a driver changes topology of its clocks
>> using
>> clk_set_parent(). The problem occurs when on one platform/SoC
>> driver's clock
>> is located at MUX output but on the other platform/SoC there is a
>> gated proxy
>> clock between the MUX and driver's clock. In such a case, driver's
>> code has to
>> be modified to use one clock for enabling and the other clock for
>> setup of a
>> parent.
>>
>> The code updates are avoided by propagating setup of a parent up one
>> level.
>>
>> Additionally, this patch adds CLK_SET_PARENT_PARENT (sorry for naming)
>> flag to
>> inform clk-core that clk_set_parent() should be propagated.
>>
>> Signed-off-by: Tomasz Stanislawski
>> ---
>> drivers/clk/clk.c|6 ++
>> include/linux/clk-provider.h |1 +
>> 2 files changed, 7 insertions(+)
>>
>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>> index dff0373..53bbfda 100644
>> --- a/drivers/clk/clk.c
>> +++ b/drivers/clk/clk.c
>> @@ -1737,6 +1737,12 @@ int clk_set_parent(struct clk *clk, struct clk
>> *parent)
>>
>> /* try finding the new parent index */
>> if (parent) {
>> +if ((clk->flags & CLK_SET_PARENT_PARENT)
>> +&& clk->num_parents == 1) {
>> +ret = clk_set_parent(clk->parent, parent);
>> +goto out;
>> +}
>> +
>> p_index = clk_fetch_parent_index(clk, parent);
>> p_rate = parent->rate;
>> if (p_index < 0) {
>> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
>> index 5119174..daa0b03 100644
>> --- a/include/linux/clk-provider.h
>> +++ b/include/linux/clk-provider.h
>> @@ -30,6 +30,7 @@
>> #define CLK_GET_RATE_NOCACHEBIT(6) /* do not use the cached clk
>> rate */
>> #define CLK_SET_RATE_NO_REPARENT BIT(7) /* don't re-parent on rate
>> change */
>> #define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk
>> accuracy */
>> +#define CLK_SET_PARENT_PARENTBIT(9) /* propagate parent change up
>> one level */
>>
>> struct clk_hw;
>> struct dentry;
>>
>
> This would be very useful, at least on Exynos platforms, with
> mux-div-gate clock paths. PARENT_PARENT sounds a bit funny, though.
>
> Reviewed-by: Tomasz Figa
Your opinion on this would be greatly appreciated.
Best regards,
Tomasz
[PATCH 1/4] clk: propagate parent change up one level
Hi,
On 04.04.2014 16:53, Tomasz Stanislawski wrote:
> This patch adds support for propagation of setup of clock's parent one level
> up.
>
> This feature is helpful when a driver changes topology of its clocks using
> clk_set_parent(). The problem occurs when on one platform/SoC driver's clock
> is located at MUX output but on the other platform/SoC there is a gated proxy
> clock between the MUX and driver's clock. In such a case, driver's code has
> to
> be modified to use one clock for enabling and the other clock for setup of a
> parent.
>
> The code updates are avoided by propagating setup of a parent up one level.
>
> Additionally, this patch adds CLK_SET_PARENT_PARENT (sorry for naming) flag to
> inform clk-core that clk_set_parent() should be propagated.
>
> Signed-off-by: Tomasz Stanislawski
> ---
> drivers/clk/clk.c|6 ++
> include/linux/clk-provider.h |1 +
> 2 files changed, 7 insertions(+)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index dff0373..53bbfda 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -1737,6 +1737,12 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
>
> /* try finding the new parent index */
> if (parent) {
> + if ((clk->flags & CLK_SET_PARENT_PARENT)
> + && clk->num_parents == 1) {
> + ret = clk_set_parent(clk->parent, parent);
> + goto out;
> + }
> +
> p_index = clk_fetch_parent_index(clk, parent);
> p_rate = parent->rate;
> if (p_index < 0) {
> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
> index 5119174..daa0b03 100644
> --- a/include/linux/clk-provider.h
> +++ b/include/linux/clk-provider.h
> @@ -30,6 +30,7 @@
> #define CLK_GET_RATE_NOCACHEBIT(6) /* do not use the cached clk
> rate */
> #define CLK_SET_RATE_NO_REPARENT BIT(7) /* don't re-parent on rate change */
> #define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk
> accuracy */
> +#define CLK_SET_PARENT_PARENTBIT(9) /* propagate parent change up
> one level */
>
> struct clk_hw;
> struct dentry;
>
This would be very useful, at least on Exynos platforms, with
mux-div-gate clock paths. PARENT_PARENT sounds a bit funny, though.
Reviewed-by: Tomasz Figa
Best regards,
Tomasz
[PATCH 1/4] clk: propagate parent change up one level
This patch adds support for propagation of setup of clock's parent one level
up.
This feature is helpful when a driver changes topology of its clocks using
clk_set_parent(). The problem occurs when on one platform/SoC driver's clock
is located at MUX output but on the other platform/SoC there is a gated proxy
clock between the MUX and driver's clock. In such a case, driver's code has to
be modified to use one clock for enabling and the other clock for setup of a
parent.
The code updates are avoided by propagating setup of a parent up one level.
Additionally, this patch adds CLK_SET_PARENT_PARENT (sorry for naming) flag to
inform clk-core that clk_set_parent() should be propagated.
Signed-off-by: Tomasz Stanislawski
---
drivers/clk/clk.c|6 ++
include/linux/clk-provider.h |1 +
2 files changed, 7 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index dff0373..53bbfda 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1737,6 +1737,12 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
/* try finding the new parent index */
if (parent) {
+ if ((clk->flags & CLK_SET_PARENT_PARENT)
+ && clk->num_parents == 1) {
+ ret = clk_set_parent(clk->parent, parent);
+ goto out;
+ }
+
p_index = clk_fetch_parent_index(clk, parent);
p_rate = parent->rate;
if (p_index < 0) {
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 5119174..daa0b03 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -30,6 +30,7 @@
#define CLK_GET_RATE_NOCACHE BIT(6) /* do not use the cached clk rate */
#define CLK_SET_RATE_NO_REPARENT BIT(7) /* don't re-parent on rate change */
#define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk accuracy
*/
+#define CLK_SET_PARENT_PARENT BIT(9) /* propagate parent change up one level
*/
struct clk_hw;
struct dentry;
--
1.7.9.5
