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// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
/*
* Copyright (c) 2016 AmLogic, Inc.
* Author: Michael Turquette <mturquette@baylibre.com>
*/
/*
* MultiPhase Locked Loops are outputs from a PLL with additional frequency
* scaling capabilities. MPLL rates are calculated as:
*
* f(N2_integer, SDM_IN ) = 2.0G/(N2_integer + SDM_IN/16384)
*/
#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include "clk-regmap.h"
#include "clk-mpll.h"
#define SDM_DEN 16384
#define N2_MIN 4
#define N2_MAX 511
static inline struct meson_clk_mpll_data *
meson_clk_mpll_data(struct clk_regmap *clk)
{
return (struct meson_clk_mpll_data *)clk->data;
}
static long rate_from_params(unsigned long parent_rate,
unsigned int sdm,
unsigned int n2)
{
unsigned long divisor = (SDM_DEN * n2) + sdm;
if (n2 < N2_MIN)
return -EINVAL;
return DIV_ROUND_UP_ULL((u64)parent_rate * SDM_DEN, divisor);
}
static void params_from_rate(unsigned long requested_rate,
unsigned long parent_rate,
unsigned int *sdm,
unsigned int *n2,
u8 flags)
{
uint64_t div = parent_rate;
uint64_t frac = do_div(div, requested_rate);
frac *= SDM_DEN;
if (flags & CLK_MESON_MPLL_ROUND_CLOSEST)
*sdm = DIV_ROUND_CLOSEST_ULL(frac, requested_rate);
else
*sdm = DIV_ROUND_UP_ULL(frac, requested_rate);
if (*sdm == SDM_DEN) {
*sdm = 0;
div += 1;
}
if (div < N2_MIN) {
*n2 = N2_MIN;
*sdm = 0;
} else if (div > N2_MAX) {
*n2 = N2_MAX;
*sdm = SDM_DEN - 1;
} else {
*n2 = div;
}
}
static unsigned long mpll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
unsigned int sdm, n2;
long rate;
sdm = meson_parm_read(clk->map, &mpll->sdm);
n2 = meson_parm_read(clk->map, &mpll->n2);
rate = rate_from_params(parent_rate, sdm, n2);
return rate < 0 ? 0 : rate;
}
static int mpll_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
unsigned int sdm, n2;
long rate;
params_from_rate(req->rate, req->best_parent_rate, &sdm, &n2,
mpll->flags);
rate = rate_from_params(req->best_parent_rate, sdm, n2);
if (rate < 0)
return rate;
req->rate = rate;
return 0;
}
static int mpll_set_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long parent_rate)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
unsigned int sdm, n2;
unsigned long flags = 0;
params_from_rate(rate, parent_rate, &sdm, &n2, mpll->flags);
if (mpll->lock)
spin_lock_irqsave(mpll->lock, flags);
else
__acquire(mpll->lock);
/* Set the fractional part */
meson_parm_write(clk->map, &mpll->sdm, sdm);
/* Set the integer divider part */
meson_parm_write(clk->map, &mpll->n2, n2);
if (mpll->lock)
spin_unlock_irqrestore(mpll->lock, flags);
else
__release(mpll->lock);
return 0;
}
static int mpll_init(struct clk_hw *hw)
{
struct clk_regmap *clk = to_clk_regmap(hw);
struct meson_clk_mpll_data *mpll = meson_clk_mpll_data(clk);
if (mpll->init_count)
regmap_multi_reg_write(clk->map, mpll->init_regs,
mpll->init_count);
/* Enable the fractional part */
meson_parm_write(clk->map, &mpll->sdm_en, 1);
/* Set spread spectrum if possible */
if (MESON_PARM_APPLICABLE(&mpll->ssen)) {
unsigned int ss =
mpll->flags & CLK_MESON_MPLL_SPREAD_SPECTRUM ? 1 : 0;
meson_parm_write(clk->map, &mpll->ssen, ss);
}
/* Set the magic misc bit if required */
if (MESON_PARM_APPLICABLE(&mpll->misc))
meson_parm_write(clk->map, &mpll->misc, 1);
return 0;
}
const struct clk_ops meson_clk_mpll_ro_ops = {
.recalc_rate = mpll_recalc_rate,
.determine_rate = mpll_determine_rate,
};
EXPORT_SYMBOL_GPL(meson_clk_mpll_ro_ops);
const struct clk_ops meson_clk_mpll_ops = {
.recalc_rate = mpll_recalc_rate,
.determine_rate = mpll_determine_rate,
.set_rate = mpll_set_rate,
.init = mpll_init,
};
EXPORT_SYMBOL_GPL(meson_clk_mpll_ops);
MODULE_DESCRIPTION("Amlogic MPLL driver");
MODULE_AUTHOR("Michael Turquette <mturquette@baylibre.com>");
MODULE_LICENSE("GPL v2");
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