/*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* Copyright (c) 2016 AmLogic, Inc.
* Author: Michael Turquette <mturquette@baylibre.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
* The full GNU General Public License is included in this distribution
* in the file called COPYING
*
* BSD LICENSE
*
* Copyright (c) 2016 AmLogic, Inc.
* Author: Michael Turquette <mturquette@baylibre.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* 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 "clkc.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)
{
uint64_t div = parent_rate;
unsigned long rem = do_div(div, requested_rate);
if (div < N2_MIN) {
*n2 = N2_MIN;
*sdm = 0;
} else if (div > N2_MAX) {
*n2 = N2_MAX;
*sdm = SDM_DEN - 1;
} else {
*n2 = div;
*sdm = DIV_ROUND_UP_ULL((u64)rem * SDM_DEN, requested_rate);
}
}
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 long mpll_round_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long *parent_rate)
{
unsigned int sdm, n2;
params_from_rate(rate, *parent_rate, &sdm, &n2);
return rate_from_params(*parent_rate, sdm, n2);
}
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);
if (mpll->lock)
spin_lock_irqsave(mpll->lock, flags);
else
__acquire(mpll->lock);
/* Enable and set the fractional part */
meson_parm_write(clk->map, &mpll->sdm, sdm);
meson_parm_write(clk->map, &mpll->sdm_en, 1);
/* Set additional fractional part enable if required */
if (MESON_PARM_APPLICABLE(&mpll->ssen))
meson_parm_write(clk->map, &mpll->ssen, 1);
/* Set the integer divider part */
meson_parm_write(clk->map, &mpll->n2, n2);
/* Set the magic misc bit if required */
if (MESON_PARM_APPLICABLE(&mpll->misc))
meson_parm_write(clk->map, &mpll->misc, 1);
if (mpll->lock)
spin_unlock_irqrestore(mpll->lock, flags);
else
__release(mpll->lock);
return 0;
}
const struct clk_ops meson_clk_mpll_ro_ops = {
.recalc_rate = mpll_recalc_rate,
.round_rate = mpll_round_rate,
};
const struct clk_ops meson_clk_mpll_ops = {
.recalc_rate = mpll_recalc_rate,
.round_rate = mpll_round_rate,
.set_rate = mpll_set_rate,
};
