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Message-ID: <20220113115745.45826-2-liang.yang@amlogic.com>
Date: Thu, 13 Jan 2022 19:57:42 +0800
From: Liang Yang <liang.yang@...ogic.com>
To: Neil Armstrong <narmstrong@...libre.com>,
Jerome Brunet <jbrunet@...libre.com>,
Kevin Hilman <khilman@...libre.com>,
Michael Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...nel.org>,
Rob Herring <robh+dt@...nel.org>, <linux-clk@...r.kernel.org>
CC: Liang Yang <liang.yang@...ogic.com>,
Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
Jianxin Pan <jianxin.pan@...ogic.com>,
Victor Wan <victor.wan@...ogic.com>,
XianWei Zhao <xianwei.zhao@...ogic.com>,
Kelvin Zhang <kelvin.zhang@...ogic.com>,
BiChao Zheng <bichao.zheng@...ogic.com>,
YongHui Yu <yonghui.yu@...ogic.com>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-amlogic@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>
Subject: [PATCH v9 1/4] clk: meson: add one based divider support for sclk
When MESON_SCLK_ONE_BASED flag is set, the sclk divider will be:
one based divider (div = val), and zero value gates the clock
Signed-off-by: Liang Yang <liang.yang@...ogic.com>
---
drivers/clk/meson/sclk-div.c | 61 +++++++++++++++++++++++-------------
drivers/clk/meson/sclk-div.h | 3 ++
2 files changed, 42 insertions(+), 22 deletions(-)
diff --git a/drivers/clk/meson/sclk-div.c b/drivers/clk/meson/sclk-div.c
index 76d31c0a3342..79c9efd28115 100644
--- a/drivers/clk/meson/sclk-div.c
+++ b/drivers/clk/meson/sclk-div.c
@@ -4,16 +4,17 @@
* Author: Jerome Brunet <jbrunet@...libre.com>
*
* Sample clock generator divider:
- * This HW divider gates with value 0 but is otherwise a zero based divider:
+ * This HW divider gates with value 0:
*
* val >= 1
- * divider = val + 1
+ * divider = val + 1 if ONE_BASED is not set, otherwise divider = val.
*
* The duty cycle may also be set for the LR clock variant. The duty cycle
* ratio is:
*
* hi = [0 - val]
- * duty_cycle = (1 + hi) / (1 + val)
+ * duty_cycle = (1 + hi) / (1 + val) if ONE_BASED is not set, otherwise:
+ * duty_cycle = hi / (1 + val)
*/
#include <linux/clk-provider.h>
@@ -28,22 +29,39 @@ meson_sclk_div_data(struct clk_regmap *clk)
return (struct meson_sclk_div_data *)clk->data;
}
-static int sclk_div_maxval(struct meson_sclk_div_data *sclk)
+static inline int sclk_get_reg(int val, unsigned char flag)
{
- return (1 << sclk->div.width) - 1;
+ if ((flag & MESON_SCLK_ONE_BASED) || !val)
+ return val;
+ else
+ return val - 1;
+}
+
+static inline int sclk_get_divider(int reg, unsigned char flag)
+{
+ if (flag & MESON_SCLK_ONE_BASED)
+ return reg;
+ else
+ return reg + 1;
}
static int sclk_div_maxdiv(struct meson_sclk_div_data *sclk)
{
- return sclk_div_maxval(sclk) + 1;
+ unsigned int reg = (1 << sclk->div.width) - 1;
+
+ return sclk_get_divider(reg, sclk->flags);
}
static int sclk_div_getdiv(struct clk_hw *hw, unsigned long rate,
- unsigned long prate, int maxdiv)
+ unsigned long prate)
{
int div = DIV_ROUND_CLOSEST_ULL((u64)prate, rate);
+ struct clk_regmap *clk = to_clk_regmap(hw);
+ struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk);
+ int mindiv = sclk_get_divider(1, sclk->flags);
+ int maxdiv = sclk_div_maxdiv(sclk);
- return clamp(div, 2, maxdiv);
+ return clamp(div, mindiv, maxdiv);
}
static int sclk_div_bestdiv(struct clk_hw *hw, unsigned long rate,
@@ -51,25 +69,25 @@ static int sclk_div_bestdiv(struct clk_hw *hw, unsigned long rate,
struct meson_sclk_div_data *sclk)
{
struct clk_hw *parent = clk_hw_get_parent(hw);
- int bestdiv = 0, i;
+ int bestdiv = 0, i, mindiv;
unsigned long maxdiv, now, parent_now;
unsigned long best = 0, best_parent = 0;
if (!rate)
rate = 1;
- maxdiv = sclk_div_maxdiv(sclk);
-
if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT))
- return sclk_div_getdiv(hw, rate, *prate, maxdiv);
+ return sclk_div_getdiv(hw, rate, *prate);
/*
* The maximum divider we can use without overflowing
* unsigned long in rate * i below
*/
+ maxdiv = sclk_div_maxdiv(sclk);
maxdiv = min(ULONG_MAX / rate, maxdiv);
+ mindiv = sclk_get_divider(1, sclk->flags);
- for (i = 2; i <= maxdiv; i++) {
+ for (i = mindiv; i <= maxdiv; i++) {
/*
* It's the most ideal case if the requested rate can be
* divided from parent clock without needing to change
@@ -115,10 +133,7 @@ static void sclk_apply_ratio(struct clk_regmap *clk,
sclk->cached_duty.num,
sclk->cached_duty.den);
- if (hi)
- hi -= 1;
-
- meson_parm_write(clk->map, &sclk->hi, hi);
+ meson_parm_write(clk->map, &sclk->hi, sclk_get_reg(hi, sclk->flags));
}
static int sclk_div_set_duty_cycle(struct clk_hw *hw,
@@ -149,7 +164,7 @@ static int sclk_div_get_duty_cycle(struct clk_hw *hw,
}
hi = meson_parm_read(clk->map, &sclk->hi);
- duty->num = hi + 1;
+ duty->num = sclk_get_divider(hi, sclk->flags);
duty->den = sclk->cached_div;
return 0;
}
@@ -157,10 +172,13 @@ static int sclk_div_get_duty_cycle(struct clk_hw *hw,
static void sclk_apply_divider(struct clk_regmap *clk,
struct meson_sclk_div_data *sclk)
{
+ unsigned int div;
+
if (MESON_PARM_APPLICABLE(&sclk->hi))
sclk_apply_ratio(clk, sclk);
- meson_parm_write(clk->map, &sclk->div, sclk->cached_div - 1);
+ div = sclk_get_reg(sclk->cached_div, sclk->flags);
+ meson_parm_write(clk->map, &sclk->div, div);
}
static int sclk_div_set_rate(struct clk_hw *hw, unsigned long rate,
@@ -168,9 +186,8 @@ static int sclk_div_set_rate(struct clk_hw *hw, unsigned long rate,
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk);
- unsigned long maxdiv = sclk_div_maxdiv(sclk);
- sclk->cached_div = sclk_div_getdiv(hw, rate, prate, maxdiv);
+ sclk->cached_div = sclk_div_getdiv(hw, rate, prate);
if (clk_hw_is_enabled(hw))
sclk_apply_divider(clk, sclk);
@@ -228,7 +245,7 @@ static int sclk_div_init(struct clk_hw *hw)
if (!val)
sclk->cached_div = sclk_div_maxdiv(sclk);
else
- sclk->cached_div = val + 1;
+ sclk->cached_div = sclk_get_divider(val, sclk->flags);
sclk_div_get_duty_cycle(hw, &sclk->cached_duty);
diff --git a/drivers/clk/meson/sclk-div.h b/drivers/clk/meson/sclk-div.h
index b64b2a32005f..944dab5ec0cf 100644
--- a/drivers/clk/meson/sclk-div.h
+++ b/drivers/clk/meson/sclk-div.h
@@ -10,11 +10,14 @@
#include <linux/clk-provider.h>
#include "parm.h"
+#define MESON_SCLK_ONE_BASED BIT(0)
+
struct meson_sclk_div_data {
struct parm div;
struct parm hi;
unsigned int cached_div;
struct clk_duty cached_duty;
+ u8 flags;
};
extern const struct clk_ops meson_sclk_div_ops;
--
2.34.1
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