[PATCH v3 4/8] clk: sunxi-ng: nm: Support finding closest rate
Frank Oltmanns
frank at oltmanns.dev
Sun Jul 2 10:55:23 PDT 2023
Incorporate a new function, ccu_nm_find_best_closest, that selects the
closest possible rate instead of the closest rate that is less than the
requested rate. Utilizing rational_best_approximation has the additional
effect of boosting performance in clock rate selection.
In cases where the CCU_FEATURE_CLOSEST_RATE flag is set, use
ccu_nm_find_best_closest instead of the original ccu_nm_find_best
function.
Extend the macro SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX to allow
selecting additional features and update all usages of the macro with no
additional flags set.
Signed-off-by: Frank Oltmanns <frank at oltmanns.dev>
---
drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 6 ++++--
drivers/clk/sunxi-ng/ccu-sun8i-h3.c | 3 ++-
drivers/clk/sunxi-ng/ccu-sun8i-r40.c | 6 ++++--
drivers/clk/sunxi-ng/ccu_nm.c | 23 +++++++++++++++++++++--
drivers/clk/sunxi-ng/ccu_nm.h | 6 ++++--
5 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
index a139a5c438d4..ebfab1fdbb96 100644
--- a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
+++ b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
@@ -80,7 +80,8 @@ static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX(pll_video0_clk, "pll-video0",
297000000, /* frac rate 1 */
BIT(31), /* gate */
BIT(28), /* lock */
- CLK_SET_RATE_UNGATE);
+ CLK_SET_RATE_UNGATE,
+ 0); /* features */
static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_ve_clk, "pll-ve",
"osc24M", 0x018,
@@ -143,7 +144,8 @@ static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX(pll_video1_clk, "pll-video1",
297000000, /* frac rate 1 */
BIT(31), /* gate */
BIT(28), /* lock */
- CLK_SET_RATE_UNGATE);
+ CLK_SET_RATE_UNGATE,
+ 0); /* features */
static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_gpu_clk, "pll-gpu",
"osc24M", 0x038,
diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c
index bfebe8dbbe65..1e2669648a24 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c
@@ -76,7 +76,8 @@ static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX(pll_video_clk, "pll-video",
297000000, /* frac rate 1 */
BIT(31), /* gate */
BIT(28), /* lock */
- CLK_SET_RATE_UNGATE);
+ CLK_SET_RATE_UNGATE,
+ 0); /* features */
static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_ve_clk, "pll-ve",
"osc24M", 0x0018,
diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
index 31eca0d3bc1e..63907b86ce06 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-r40.c
@@ -82,7 +82,8 @@ static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX(pll_video0_clk, "pll-video0",
297000000, /* frac rate 1 */
BIT(31), /* gate */
BIT(28), /* lock */
- CLK_SET_RATE_UNGATE);
+ CLK_SET_RATE_UNGATE,
+ 0); /* features */
/* TODO: The result of N/M is required to be in [8, 25] range. */
static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_ve_clk, "pll-ve",
@@ -169,7 +170,8 @@ static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN_MAX(pll_video1_clk, "pll-video1",
297000000, /* frac rate 1 */
BIT(31), /* gate */
BIT(28), /* lock */
- CLK_SET_RATE_UNGATE);
+ CLK_SET_RATE_UNGATE,
+ 0); /* features */
static struct ccu_nkm pll_sata_clk = {
.enable = BIT(31),
diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c
index c1fd11542c45..97d8d9e3255c 100644
--- a/drivers/clk/sunxi-ng/ccu_nm.c
+++ b/drivers/clk/sunxi-ng/ccu_nm.c
@@ -6,6 +6,7 @@
#include <linux/clk-provider.h>
#include <linux/io.h>
+#include <linux/rational.h>
#include "ccu_frac.h"
#include "ccu_gate.h"
@@ -56,6 +57,18 @@ static unsigned long ccu_nm_find_best(unsigned long parent, unsigned long rate,
return best_rate;
}
+static unsigned long ccu_nm_find_best_closest(unsigned long parent, unsigned long rate,
+ struct _ccu_nm *nm)
+{
+ unsigned long best_rate = 0;
+
+ rational_best_approximation(rate, parent, nm->max_n, nm->max_m, &nm->n, &nm->m);
+
+ best_rate = ccu_nm_calc_rate(parent, nm->n, nm->m);
+
+ return best_rate;
+}
+
static void ccu_nm_disable(struct clk_hw *hw)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
@@ -159,7 +172,10 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
_nm.min_m = 1;
_nm.max_m = nm->m.max ?: 1 << nm->m.width;
- rate = ccu_nm_find_best(*parent_rate, rate, &_nm);
+ if (nm->common.features & CCU_FEATURE_CLOSEST_RATE)
+ rate = ccu_nm_find_best_closest(*parent_rate, rate, &_nm);
+ else
+ rate = ccu_nm_find_best(*parent_rate, rate, &_nm);
if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
@@ -210,7 +226,10 @@ static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
&_nm.m, &_nm.n);
} else {
ccu_sdm_helper_disable(&nm->common, &nm->sdm);
- ccu_nm_find_best(parent_rate, rate, &_nm);
+ if (nm->common.features & CCU_FEATURE_CLOSEST_RATE)
+ ccu_nm_find_best_closest(parent_rate, rate, &_nm);
+ else
+ ccu_nm_find_best(parent_rate, rate, &_nm);
}
spin_lock_irqsave(nm->common.lock, flags);
diff --git a/drivers/clk/sunxi-ng/ccu_nm.h b/drivers/clk/sunxi-ng/ccu_nm.h
index 2904e67f05a8..a3825c4e8d42 100644
--- a/drivers/clk/sunxi-ng/ccu_nm.h
+++ b/drivers/clk/sunxi-ng/ccu_nm.h
@@ -116,7 +116,8 @@ struct ccu_nm {
_frac_en, _frac_sel, \
_frac_rate_0, \
_frac_rate_1, \
- _gate, _lock, _flags) \
+ _gate, _lock, _flags, \
+ _features) \
struct ccu_nm _struct = { \
.enable = _gate, \
.lock = _lock, \
@@ -129,7 +130,8 @@ struct ccu_nm {
.max_rate = _max_rate, \
.common = { \
.reg = _reg, \
- .features = CCU_FEATURE_FRACTIONAL, \
+ .features = CCU_FEATURE_FRACTIONAL | \
+ _features, \
.hw.init = CLK_HW_INIT(_name, \
_parent, \
&ccu_nm_ops, \
--
2.41.0
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