In case the CLK_SET_RATE_PARENT flag is set, consider using a different
parent rate when determining a new rate.
To find the best match for the requested rate, perform the following
steps for each NKM combination:
- calculate the optimal parent rate,
- find the best parent rate that the parent clock actually supports
- use that parent rate to calculate the effective rate.
In case the clk does not support setting the parent rate, use the same
algorithm as before.
Acked-by: Maxime Ripard <[email protected]>
Signed-off-by: Frank Oltmanns <[email protected]>
---
drivers/clk/sunxi-ng/ccu_nkm.c | 45 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index f267142e58b3..ea1b77e9b57f 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -6,6 +6,7 @@
#include <linux/clk-provider.h>
#include <linux/io.h>
+#include <linux/math.h>
#include "ccu_gate.h"
#include "ccu_nkm.h"
@@ -16,6 +17,45 @@ struct _ccu_nkm {
unsigned long m, min_m, max_m;
};
+static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *parent_hw,
+ unsigned long *parent, unsigned long rate,
+ struct _ccu_nkm *nkm)
+{
+ unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent = *parent;
+ unsigned long best_n = 0, best_k = 0, best_m = 0;
+ unsigned long _n, _k, _m;
+
+ for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
+ for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
+ for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
+ unsigned long tmp_rate;
+
+ tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
+
+ tmp_rate = tmp_parent * _n * _k / _m;
+ if (tmp_rate > rate)
+ continue;
+
+ if ((rate - tmp_rate) < (rate - best_rate)) {
+ best_rate = tmp_rate;
+ best_parent_rate = tmp_parent;
+ best_n = _n;
+ best_k = _k;
+ best_m = _m;
+ }
+ }
+ }
+ }
+
+ nkm->n = best_n;
+ nkm->k = best_k;
+ nkm->m = best_m;
+
+ *parent = best_parent_rate;
+
+ return best_rate;
+}
+
static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
struct _ccu_nkm *nkm)
{
@@ -124,7 +164,10 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate *= nkm->fixed_post_div;
- rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
+ if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
+ rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
+ else
+ rate = ccu_nkm_find_best_with_parent_adj(parent_hw, parent_rate, rate, &_nkm);
if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nkm->fixed_post_div;
--
2.41.0
On 2023-08-06 at 15:32:29 +0200, Jernej Škrabec <[email protected]> wrote:
> Dne nedelja, 06. avgust 2023 ob 15:06:47 CEST je Frank Oltmanns napisal(a):
>> In case the CLK_SET_RATE_PARENT flag is set, consider using a different
>> parent rate when determining a new rate.
>>
>> To find the best match for the requested rate, perform the following
>> steps for each NKM combination:
>> - calculate the optimal parent rate,
>> - find the best parent rate that the parent clock actually supports
>> - use that parent rate to calculate the effective rate.
>>
>> In case the clk does not support setting the parent rate, use the same
>> algorithm as before.
>>
>> Acked-by: Maxime Ripard <[email protected]>
>> Signed-off-by: Frank Oltmanns <[email protected]>
>> ---
>> drivers/clk/sunxi-ng/ccu_nkm.c | 45
>> +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 44
>> insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
>> index f267142e58b3..ea1b77e9b57f 100644
>> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
>> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
>> @@ -6,6 +6,7 @@
>>
>> #include <linux/clk-provider.h>
>> #include <linux/io.h>
>> +#include <linux/math.h>
>
> Why do you need above include?
It's not needed. It's a leftover from an earlier version. I'll remove it
in v6.
Thank you for your review,
Frank
>
> Best regards,
> Jernej
>
>>
>> #include "ccu_gate.h"
>> #include "ccu_nkm.h"
>> @@ -16,6 +17,45 @@ struct _ccu_nkm {
>> unsigned long m, min_m, max_m;
>> };
>>
>> +static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw
>> *parent_hw, +
> unsigned long *parent, unsigned long rate,
>> +
> struct _ccu_nkm *nkm)
>> +{
>> + unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent
> =
>> *parent; + unsigned long best_n = 0, best_k = 0, best_m = 0;
>> + unsigned long _n, _k, _m;
>> +
>> + for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
>> + for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
>> + for (_m = nkm->min_m; _m <= nkm->max_m; _m++)
> {
>> + unsigned long tmp_rate;
>> +
>> + tmp_parent =
> clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
>> +
>> + tmp_rate = tmp_parent * _n * _k /
> _m;
>> + if (tmp_rate > rate)
>> + continue;
>> +
>> + if ((rate - tmp_rate) < (rate -
> best_rate)) {
>> + best_rate = tmp_rate;
>> + best_parent_rate =
> tmp_parent;
>> + best_n = _n;
>> + best_k = _k;
>> + best_m = _m;
>> + }
>> + }
>> + }
>> + }
>> +
>> + nkm->n = best_n;
>> + nkm->k = best_k;
>> + nkm->m = best_m;
>> +
>> + *parent = best_parent_rate;
>> +
>> + return best_rate;
>> +}
>> +
>> static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long
>> rate, struct _ccu_nkm *nkm)
>> {
>> @@ -124,7 +164,10 @@ static unsigned long ccu_nkm_round_rate(struct
>> ccu_mux_internal *mux, if (nkm->common.features &
>> CCU_FEATURE_FIXED_POSTDIV)
>> rate *= nkm->fixed_post_div;
>>
>> - rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
>> + if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
>> + rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
>> + else
>> + rate = ccu_nkm_find_best_with_parent_adj(parent_hw,
> parent_rate, rate,
>> &_nkm);
>>
>> if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
>> rate /= nkm->fixed_post_div;
Dne nedelja, 06. avgust 2023 ob 15:06:47 CEST je Frank Oltmanns napisal(a):
> In case the CLK_SET_RATE_PARENT flag is set, consider using a different
> parent rate when determining a new rate.
>
> To find the best match for the requested rate, perform the following
> steps for each NKM combination:
> - calculate the optimal parent rate,
> - find the best parent rate that the parent clock actually supports
> - use that parent rate to calculate the effective rate.
>
> In case the clk does not support setting the parent rate, use the same
> algorithm as before.
>
> Acked-by: Maxime Ripard <[email protected]>
> Signed-off-by: Frank Oltmanns <[email protected]>
> ---
> drivers/clk/sunxi-ng/ccu_nkm.c | 45
> +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 44
> insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> index f267142e58b3..ea1b77e9b57f 100644
> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> @@ -6,6 +6,7 @@
>
> #include <linux/clk-provider.h>
> #include <linux/io.h>
> +#include <linux/math.h>
Why do you need above include?
Best regards,
Jernej
>
> #include "ccu_gate.h"
> #include "ccu_nkm.h"
> @@ -16,6 +17,45 @@ struct _ccu_nkm {
> unsigned long m, min_m, max_m;
> };
>
> +static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw
> *parent_hw, +
unsigned long *parent, unsigned long rate,
> +
struct _ccu_nkm *nkm)
> +{
> + unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent
=
> *parent; + unsigned long best_n = 0, best_k = 0, best_m = 0;
> + unsigned long _n, _k, _m;
> +
> + for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
> + for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
> + for (_m = nkm->min_m; _m <= nkm->max_m; _m++)
{
> + unsigned long tmp_rate;
> +
> + tmp_parent =
clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
> +
> + tmp_rate = tmp_parent * _n * _k /
_m;
> + if (tmp_rate > rate)
> + continue;
> +
> + if ((rate - tmp_rate) < (rate -
best_rate)) {
> + best_rate = tmp_rate;
> + best_parent_rate =
tmp_parent;
> + best_n = _n;
> + best_k = _k;
> + best_m = _m;
> + }
> + }
> + }
> + }
> +
> + nkm->n = best_n;
> + nkm->k = best_k;
> + nkm->m = best_m;
> +
> + *parent = best_parent_rate;
> +
> + return best_rate;
> +}
> +
> static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long
> rate, struct _ccu_nkm *nkm)
> {
> @@ -124,7 +164,10 @@ static unsigned long ccu_nkm_round_rate(struct
> ccu_mux_internal *mux, if (nkm->common.features &
> CCU_FEATURE_FIXED_POSTDIV)
> rate *= nkm->fixed_post_div;
>
> - rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
> + if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
> + rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
> + else
> + rate = ccu_nkm_find_best_with_parent_adj(parent_hw,
parent_rate, rate,
> &_nkm);
>
> if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
> rate /= nkm->fixed_post_div;