* [PATCH] clk: bcm/kona: implement determine_rate()
@ 2014-05-20 13:24 Alex Elder
2014-05-23 23:18 ` Mike Turquette
0 siblings, 1 reply; 4+ messages in thread
From: Alex Elder @ 2014-05-20 13:24 UTC (permalink / raw)
To: linux-arm-kernel
Implement the clk->determine_rate method for Broadcom Kona peripheral
clocks. This allows a peripheral clock to be re-parented in order to
satisfy a rate change request. This takes the place of the previous
kona_peri_clk_round_rate() functionality, though that function remains
because it is used by the new one.
The parent clock that allows the peripheral clock to produce a rate
closest to the one requested is the one selected, though the current
parent is used by default.
Signed-off-by: Alex Elder <elder@linaro.org>
---
This patch is based on Mike Turquette's current "clk-next" branch.
6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern...
It is available here:
http://git.linaro.org/landing-teams/working/broadcom/kernel.git
Branch review/bcm-determine-rate
drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 52 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c
index d603c4e..1a4eccc 100644
--- a/drivers/clk/bcm/clk-kona.c
+++ b/drivers/clk/bcm/clk-kona.c
@@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate,
rate ? rate : 1, *parent_rate, NULL);
}
+static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *best_parent_rate, struct clk **best_parent)
+{
+ struct kona_clk *bcm_clk = to_kona_clk(hw);
+ struct clk *clk = hw->clk;
+ struct clk *current_parent;
+ unsigned long parent_rate;
+ unsigned long best_delta;
+ unsigned long best_rate;
+ u32 parent_count;
+ u32 which;
+
+ /*
+ * If there is no other parent to choose, use the current one.
+ * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT.
+ */
+ parent_count = (u32)bcm_clk->init_data.num_parents;
+ if (parent_count < 2)
+ return kona_peri_clk_round_rate(hw, rate, best_parent_rate);
+
+ /* Unless we can do better, stick with current parent */
+ current_parent = clk_get_parent(clk);
+ parent_rate = __clk_get_rate(current_parent);
+ best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
+ best_delta = abs(best_rate - rate);
+
+ /* Check whether any other parent clock can produce a better result */
+ for (which = 0; which < parent_count; which++) {
+ struct clk *parent = clk_get_parent_by_index(clk, which);
+ unsigned long delta;
+ unsigned long other_rate;
+
+ BUG_ON(!parent);
+ if (parent == current_parent)
+ continue;
+
+ /* We don't support CLK_SET_RATE_PARENT */
+ parent_rate = __clk_get_rate(parent);
+ other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
+ delta = abs(other_rate - rate);
+ if (delta < best_delta) {
+ best_delta = delta;
+ best_rate = other_rate;
+ *best_parent = parent;
+ *best_parent_rate = parent_rate;
+ }
+ }
+
+ return best_rate;
+}
+
static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
{
struct kona_clk *bcm_clk = to_kona_clk(hw);
@@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = {
.disable = kona_peri_clk_disable,
.is_enabled = kona_peri_clk_is_enabled,
.recalc_rate = kona_peri_clk_recalc_rate,
- .round_rate = kona_peri_clk_round_rate,
+ .determine_rate = kona_peri_clk_determine_rate,
.set_parent = kona_peri_clk_set_parent,
.get_parent = kona_peri_clk_get_parent,
.set_rate = kona_peri_clk_set_rate,
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] clk: bcm/kona: implement determine_rate()
2014-05-20 13:24 [PATCH] clk: bcm/kona: implement determine_rate() Alex Elder
@ 2014-05-23 23:18 ` Mike Turquette
2014-05-23 23:24 ` Alex Elder
0 siblings, 1 reply; 4+ messages in thread
From: Mike Turquette @ 2014-05-23 23:18 UTC (permalink / raw)
To: linux-arm-kernel
Quoting Alex Elder (2014-05-20 06:24:57)
> Implement the clk->determine_rate method for Broadcom Kona peripheral
> clocks. This allows a peripheral clock to be re-parented in order to
> satisfy a rate change request. This takes the place of the previous
> kona_peri_clk_round_rate() functionality, though that function remains
> because it is used by the new one.
>
> The parent clock that allows the peripheral clock to produce a rate
> closest to the one requested is the one selected, though the current
> parent is used by default.
>
> Signed-off-by: Alex Elder <elder@linaro.org>
> ---
> This patch is based on Mike Turquette's current "clk-next" branch.
> 6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern...
>
> It is available here:
> http://git.linaro.org/landing-teams/working/broadcom/kernel.git
> Branch review/bcm-determine-rate
>
> drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c
> index d603c4e..1a4eccc 100644
> --- a/drivers/clk/bcm/clk-kona.c
> +++ b/drivers/clk/bcm/clk-kona.c
> @@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate,
> rate ? rate : 1, *parent_rate, NULL);
> }
>
> +static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *best_parent_rate, struct clk **best_parent)
> +{
> + struct kona_clk *bcm_clk = to_kona_clk(hw);
> + struct clk *clk = hw->clk;
> + struct clk *current_parent;
> + unsigned long parent_rate;
> + unsigned long best_delta;
> + unsigned long best_rate;
> + u32 parent_count;
> + u32 which;
> +
> + /*
> + * If there is no other parent to choose, use the current one.
> + * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT.
> + */
A WARN_ONCE is appropriate upon detection of CLK_SET_RATE_NO_REPARENT.
It will certainly help someone that is debugging why that flag has no
effect.
Otherwise the patch looks good to me.
Regards,
Mike
> + parent_count = (u32)bcm_clk->init_data.num_parents;
> + if (parent_count < 2)
> + return kona_peri_clk_round_rate(hw, rate, best_parent_rate);
> +
> + /* Unless we can do better, stick with current parent */
> + current_parent = clk_get_parent(clk);
> + parent_rate = __clk_get_rate(current_parent);
> + best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
> + best_delta = abs(best_rate - rate);
> +
> + /* Check whether any other parent clock can produce a better result */
> + for (which = 0; which < parent_count; which++) {
> + struct clk *parent = clk_get_parent_by_index(clk, which);
> + unsigned long delta;
> + unsigned long other_rate;
> +
> + BUG_ON(!parent);
> + if (parent == current_parent)
> + continue;
> +
> + /* We don't support CLK_SET_RATE_PARENT */
> + parent_rate = __clk_get_rate(parent);
> + other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
> + delta = abs(other_rate - rate);
> + if (delta < best_delta) {
> + best_delta = delta;
> + best_rate = other_rate;
> + *best_parent = parent;
> + *best_parent_rate = parent_rate;
> + }
> + }
> +
> + return best_rate;
> +}
> +
> static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
> {
> struct kona_clk *bcm_clk = to_kona_clk(hw);
> @@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = {
> .disable = kona_peri_clk_disable,
> .is_enabled = kona_peri_clk_is_enabled,
> .recalc_rate = kona_peri_clk_recalc_rate,
> - .round_rate = kona_peri_clk_round_rate,
> + .determine_rate = kona_peri_clk_determine_rate,
> .set_parent = kona_peri_clk_set_parent,
> .get_parent = kona_peri_clk_get_parent,
> .set_rate = kona_peri_clk_set_rate,
> --
> 1.9.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] clk: bcm/kona: implement determine_rate()
2014-05-23 23:18 ` Mike Turquette
@ 2014-05-23 23:24 ` Alex Elder
2014-05-24 0:56 ` Mike Turquette
0 siblings, 1 reply; 4+ messages in thread
From: Alex Elder @ 2014-05-23 23:24 UTC (permalink / raw)
To: linux-arm-kernel
On 05/23/2014 06:18 PM, Mike Turquette wrote:
> Quoting Alex Elder (2014-05-20 06:24:57)
>> Implement the clk->determine_rate method for Broadcom Kona peripheral
>> clocks. This allows a peripheral clock to be re-parented in order to
>> satisfy a rate change request. This takes the place of the previous
>> kona_peri_clk_round_rate() functionality, though that function remains
>> because it is used by the new one.
>>
>> The parent clock that allows the peripheral clock to produce a rate
>> closest to the one requested is the one selected, though the current
>> parent is used by default.
>>
>> Signed-off-by: Alex Elder <elder@linaro.org>
>> ---
>> This patch is based on Mike Turquette's current "clk-next" branch.
>> 6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern...
>>
>> It is available here:
>> http://git.linaro.org/landing-teams/working/broadcom/kernel.git
>> Branch review/bcm-determine-rate
>>
>> drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++-
>> 1 file changed, 52 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c
>> index d603c4e..1a4eccc 100644
>> --- a/drivers/clk/bcm/clk-kona.c
>> +++ b/drivers/clk/bcm/clk-kona.c
>> @@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate,
>> rate ? rate : 1, *parent_rate, NULL);
>> }
>>
>> +static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate,
>> + unsigned long *best_parent_rate, struct clk **best_parent)
>> +{
>> + struct kona_clk *bcm_clk = to_kona_clk(hw);
>> + struct clk *clk = hw->clk;
>> + struct clk *current_parent;
>> + unsigned long parent_rate;
>> + unsigned long best_delta;
>> + unsigned long best_rate;
>> + u32 parent_count;
>> + u32 which;
>> +
>> + /*
>> + * If there is no other parent to choose, use the current one.
>> + * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT.
>> + */
>
> A WARN_ONCE is appropriate upon detection of CLK_SET_RATE_NO_REPARENT.
> It will certainly help someone that is debugging why that flag has no
> effect.
I'll add that.
> Otherwise the patch looks good to me.
Would you like me to send an updated patch as a pull request?
Thanks.
-Alex
> Regards,
> Mike
>
>> + parent_count = (u32)bcm_clk->init_data.num_parents;
>> + if (parent_count < 2)
>> + return kona_peri_clk_round_rate(hw, rate, best_parent_rate);
>> +
>> + /* Unless we can do better, stick with current parent */
>> + current_parent = clk_get_parent(clk);
>> + parent_rate = __clk_get_rate(current_parent);
>> + best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
>> + best_delta = abs(best_rate - rate);
>> +
>> + /* Check whether any other parent clock can produce a better result */
>> + for (which = 0; which < parent_count; which++) {
>> + struct clk *parent = clk_get_parent_by_index(clk, which);
>> + unsigned long delta;
>> + unsigned long other_rate;
>> +
>> + BUG_ON(!parent);
>> + if (parent == current_parent)
>> + continue;
>> +
>> + /* We don't support CLK_SET_RATE_PARENT */
>> + parent_rate = __clk_get_rate(parent);
>> + other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
>> + delta = abs(other_rate - rate);
>> + if (delta < best_delta) {
>> + best_delta = delta;
>> + best_rate = other_rate;
>> + *best_parent = parent;
>> + *best_parent_rate = parent_rate;
>> + }
>> + }
>> +
>> + return best_rate;
>> +}
>> +
>> static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
>> {
>> struct kona_clk *bcm_clk = to_kona_clk(hw);
>> @@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = {
>> .disable = kona_peri_clk_disable,
>> .is_enabled = kona_peri_clk_is_enabled,
>> .recalc_rate = kona_peri_clk_recalc_rate,
>> - .round_rate = kona_peri_clk_round_rate,
>> + .determine_rate = kona_peri_clk_determine_rate,
>> .set_parent = kona_peri_clk_set_parent,
>> .get_parent = kona_peri_clk_get_parent,
>> .set_rate = kona_peri_clk_set_rate,
>> --
>> 1.9.1
>>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] clk: bcm/kona: implement determine_rate()
2014-05-23 23:24 ` Alex Elder
@ 2014-05-24 0:56 ` Mike Turquette
0 siblings, 0 replies; 4+ messages in thread
From: Mike Turquette @ 2014-05-24 0:56 UTC (permalink / raw)
To: linux-arm-kernel
Quoting Alex Elder (2014-05-23 16:24:31)
> On 05/23/2014 06:18 PM, Mike Turquette wrote:
> > Quoting Alex Elder (2014-05-20 06:24:57)
> >> Implement the clk->determine_rate method for Broadcom Kona peripheral
> >> clocks. This allows a peripheral clock to be re-parented in order to
> >> satisfy a rate change request. This takes the place of the previous
> >> kona_peri_clk_round_rate() functionality, though that function remains
> >> because it is used by the new one.
> >>
> >> The parent clock that allows the peripheral clock to produce a rate
> >> closest to the one requested is the one selected, though the current
> >> parent is used by default.
> >>
> >> Signed-off-by: Alex Elder <elder@linaro.org>
> >> ---
> >> This patch is based on Mike Turquette's current "clk-next" branch.
> >> 6ed8eb5 Merge tag 'clk-hisi-for-v3.16' of https://git.kern...
> >>
> >> It is available here:
> >> http://git.linaro.org/landing-teams/working/broadcom/kernel.git
> >> Branch review/bcm-determine-rate
> >>
> >> drivers/clk/bcm/clk-kona.c | 53 +++++++++++++++++++++++++++++++++++++++++++++-
> >> 1 file changed, 52 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c
> >> index d603c4e..1a4eccc 100644
> >> --- a/drivers/clk/bcm/clk-kona.c
> >> +++ b/drivers/clk/bcm/clk-kona.c
> >> @@ -1031,6 +1031,57 @@ static long kona_peri_clk_round_rate(struct clk_hw *hw, unsigned long rate,
> >> rate ? rate : 1, *parent_rate, NULL);
> >> }
> >>
> >> +static long kona_peri_clk_determine_rate(struct clk_hw *hw, unsigned long rate,
> >> + unsigned long *best_parent_rate, struct clk **best_parent)
> >> +{
> >> + struct kona_clk *bcm_clk = to_kona_clk(hw);
> >> + struct clk *clk = hw->clk;
> >> + struct clk *current_parent;
> >> + unsigned long parent_rate;
> >> + unsigned long best_delta;
> >> + unsigned long best_rate;
> >> + u32 parent_count;
> >> + u32 which;
> >> +
> >> + /*
> >> + * If there is no other parent to choose, use the current one.
> >> + * Note: We don't honor (or use) CLK_SET_RATE_NO_REPARENT.
> >> + */
> >
> > A WARN_ONCE is appropriate upon detection of CLK_SET_RATE_NO_REPARENT.
> > It will certainly help someone that is debugging why that flag has no
> > effect.
>
> I'll add that.
Thanks!
>
> > Otherwise the patch looks good to me.
>
> Would you like me to send an updated patch as a pull request?
It's up to you. For a single patch I can easily pick it. If you want to
bundle it up with the other pending patches (prereq clocks, etc) then a
pull request would be nice once all that stuff gets sorted.
Regards,
Mike
>
> Thanks.
>
> -Alex
>
> > Regards,
> > Mike
> >
> >> + parent_count = (u32)bcm_clk->init_data.num_parents;
> >> + if (parent_count < 2)
> >> + return kona_peri_clk_round_rate(hw, rate, best_parent_rate);
> >> +
> >> + /* Unless we can do better, stick with current parent */
> >> + current_parent = clk_get_parent(clk);
> >> + parent_rate = __clk_get_rate(current_parent);
> >> + best_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
> >> + best_delta = abs(best_rate - rate);
> >> +
> >> + /* Check whether any other parent clock can produce a better result */
> >> + for (which = 0; which < parent_count; which++) {
> >> + struct clk *parent = clk_get_parent_by_index(clk, which);
> >> + unsigned long delta;
> >> + unsigned long other_rate;
> >> +
> >> + BUG_ON(!parent);
> >> + if (parent == current_parent)
> >> + continue;
> >> +
> >> + /* We don't support CLK_SET_RATE_PARENT */
> >> + parent_rate = __clk_get_rate(parent);
> >> + other_rate = kona_peri_clk_round_rate(hw, rate, &parent_rate);
> >> + delta = abs(other_rate - rate);
> >> + if (delta < best_delta) {
> >> + best_delta = delta;
> >> + best_rate = other_rate;
> >> + *best_parent = parent;
> >> + *best_parent_rate = parent_rate;
> >> + }
> >> + }
> >> +
> >> + return best_rate;
> >> +}
> >> +
> >> static int kona_peri_clk_set_parent(struct clk_hw *hw, u8 index)
> >> {
> >> struct kona_clk *bcm_clk = to_kona_clk(hw);
> >> @@ -1135,7 +1186,7 @@ struct clk_ops kona_peri_clk_ops = {
> >> .disable = kona_peri_clk_disable,
> >> .is_enabled = kona_peri_clk_is_enabled,
> >> .recalc_rate = kona_peri_clk_recalc_rate,
> >> - .round_rate = kona_peri_clk_round_rate,
> >> + .determine_rate = kona_peri_clk_determine_rate,
> >> .set_parent = kona_peri_clk_set_parent,
> >> .get_parent = kona_peri_clk_get_parent,
> >> .set_rate = kona_peri_clk_set_rate,
> >> --
> >> 1.9.1
> >>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2014-05-20 13:24 [PATCH] clk: bcm/kona: implement determine_rate() Alex Elder
2014-05-23 23:18 ` Mike Turquette
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2014-05-24 0:56 ` Mike Turquette
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