Commit a8d552a6 authored by Jerome Brunet's avatar Jerome Brunet Committed by Neil Armstrong

clk: meson: add dual divider clock driver

Add the dual divider driver. This special divider make a weighted
average between 2 dividers to reach fractional divider values.
Signed-off-by: default avatarJerome Brunet <jbrunet@baylibre.com>
Acked-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181221160239.26265-4-jbrunet@baylibre.com
parent 8d9981ef
...@@ -3,7 +3,7 @@ ...@@ -3,7 +3,7 @@
# #
obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o vid-pll-div.o obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o vid-pll-div.o
obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-input.o obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-input.o clk-dualdiv.o
obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO) += clk-triphase.o sclk-div.o obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO) += clk-triphase.o sclk-div.o
obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o
obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
......
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2017 BayLibre, SAS
* Author: Neil Armstrong <narmstrong@baylibre.com>
* Author: Jerome Brunet <jbrunet@baylibre.com>
*/
/*
* The AO Domain embeds a dual/divider to generate a more precise
* 32,768KHz clock for low-power suspend mode and CEC.
* ______ ______
* | | | |
* | Div1 |-| Cnt1 |
* /|______| |______|\
* -| ______ ______ X--> Out
* \| | | |/
* | Div2 |-| Cnt2 |
* |______| |______|
*
* The dividing can be switched to single or dual, with a counter
* for each divider to set when the switching is done.
*/
#include <linux/clk-provider.h>
#include "clkc.h"
static inline struct meson_clk_dualdiv_data *
meson_clk_dualdiv_data(struct clk_regmap *clk)
{
return (struct meson_clk_dualdiv_data *)clk->data;
}
static unsigned long
__dualdiv_param_to_rate(unsigned long parent_rate,
const struct meson_clk_dualdiv_param *p)
{
if (!p->dual)
return DIV_ROUND_CLOSEST(parent_rate, p->n1);
return DIV_ROUND_CLOSEST(parent_rate * (p->m1 + p->m2),
p->n1 * p->m1 + p->n2 * p->m2);
}
static unsigned long meson_clk_dualdiv_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_clk_dualdiv_data *dualdiv = meson_clk_dualdiv_data(clk);
struct meson_clk_dualdiv_param setting;
setting.dual = meson_parm_read(clk->map, &dualdiv->dual);
setting.n1 = meson_parm_read(clk->map, &dualdiv->n1) + 1;
setting.m1 = meson_parm_read(clk->map, &dualdiv->m1) + 1;
setting.n2 = meson_parm_read(clk->map, &dualdiv->n2) + 1;
setting.m2 = meson_parm_read(clk->map, &dualdiv->m2) + 1;
return __dualdiv_param_to_rate(parent_rate, &setting);
}
static const struct meson_clk_dualdiv_param *
__dualdiv_get_setting(unsigned long rate, unsigned long parent_rate,
struct meson_clk_dualdiv_data *dualdiv)
{
const struct meson_clk_dualdiv_param *table = dualdiv->table;
unsigned long best = 0, now = 0;
unsigned int i, best_i = 0;
if (!table)
return NULL;
for (i = 0; table[i].n1; i++) {
now = __dualdiv_param_to_rate(parent_rate, &table[i]);
/* If we get an exact match, don't bother any further */
if (now == rate) {
return &table[i];
} else if (abs(now - rate) < abs(best - rate)) {
best = now;
best_i = i;
}
}
return (struct meson_clk_dualdiv_param *)&table[best_i];
}
static long meson_clk_dualdiv_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_clk_dualdiv_data *dualdiv = meson_clk_dualdiv_data(clk);
const struct meson_clk_dualdiv_param *setting =
__dualdiv_get_setting(rate, *parent_rate, dualdiv);
if (!setting)
return meson_clk_dualdiv_recalc_rate(hw, *parent_rate);
return __dualdiv_param_to_rate(*parent_rate, setting);
}
static int meson_clk_dualdiv_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_clk_dualdiv_data *dualdiv = meson_clk_dualdiv_data(clk);
const struct meson_clk_dualdiv_param *setting =
__dualdiv_get_setting(rate, parent_rate, dualdiv);
if (!setting)
return -EINVAL;
meson_parm_write(clk->map, &dualdiv->dual, setting->dual);
meson_parm_write(clk->map, &dualdiv->n1, setting->n1 - 1);
meson_parm_write(clk->map, &dualdiv->m1, setting->m1 - 1);
meson_parm_write(clk->map, &dualdiv->n2, setting->n2 - 1);
meson_parm_write(clk->map, &dualdiv->m2, setting->m2 - 1);
return 0;
}
const struct clk_ops meson_clk_dualdiv_ops = {
.recalc_rate = meson_clk_dualdiv_recalc_rate,
.round_rate = meson_clk_dualdiv_round_rate,
.set_rate = meson_clk_dualdiv_set_rate,
};
EXPORT_SYMBOL_GPL(meson_clk_dualdiv_ops);
const struct clk_ops meson_clk_dualdiv_ro_ops = {
.recalc_rate = meson_clk_dualdiv_recalc_rate,
};
EXPORT_SYMBOL_GPL(meson_clk_dualdiv_ro_ops);
...@@ -110,6 +110,23 @@ struct clk_regmap _name = { \ ...@@ -110,6 +110,23 @@ struct clk_regmap _name = { \
}, \ }, \
}; };
struct meson_clk_dualdiv_param {
unsigned int n1;
unsigned int n2;
unsigned int m1;
unsigned int m2;
unsigned int dual;
};
struct meson_clk_dualdiv_data {
struct parm n1;
struct parm n2;
struct parm m1;
struct parm m2;
struct parm dual;
const struct meson_clk_dualdiv_param *table;
};
/* clk_ops */ /* clk_ops */
extern const struct clk_ops meson_clk_pll_ro_ops; extern const struct clk_ops meson_clk_pll_ro_ops;
extern const struct clk_ops meson_clk_pll_ops; extern const struct clk_ops meson_clk_pll_ops;
...@@ -118,6 +135,8 @@ extern const struct clk_ops meson_clk_mpll_ro_ops; ...@@ -118,6 +135,8 @@ extern const struct clk_ops meson_clk_mpll_ro_ops;
extern const struct clk_ops meson_clk_mpll_ops; extern const struct clk_ops meson_clk_mpll_ops;
extern const struct clk_ops meson_clk_phase_ops; extern const struct clk_ops meson_clk_phase_ops;
extern const struct clk_ops meson_vid_pll_div_ro_ops; extern const struct clk_ops meson_vid_pll_div_ro_ops;
extern const struct clk_ops meson_clk_dualdiv_ops;
extern const struct clk_ops meson_clk_dualdiv_ro_ops;
struct clk_hw *meson_clk_hw_register_input(struct device *dev, struct clk_hw *meson_clk_hw_register_input(struct device *dev,
const char *of_name, const char *of_name,
......
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