linux_dsm_epyc7002/drivers/clk/meson/clk-mpll.c
Michael Turquette 1c50da4f27 clk: meson: add mpll support
MPLLs are adjustable rate clocks derived from PLLs. On both Meson8b and
GXBB they appear to be only derived from fixed_pll.

Add support for these clock types so that they can be added to their
respective drivers.

Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
2016-06-22 18:02:59 -07:00

95 lines
3.5 KiB
C

/*
* This file is provided under a dual BSD/GPLv2 license. When using or
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* 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.
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* BSD LICENSE
*
* Copyright (c) 2016 AmLogic, Inc.
* Author: Michael Turquette <mturquette@baylibre.com>
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/*
* 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_MAX 16384
#define to_meson_clk_mpll(_hw) container_of(_hw, struct meson_clk_mpll, hw)
static unsigned long mpll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct meson_clk_mpll *mpll = to_meson_clk_mpll(hw);
struct parm *p;
unsigned long rate = 0;
unsigned long reg, sdm, n2;
p = &mpll->sdm;
reg = readl(mpll->base + p->reg_off);
sdm = PARM_GET(p->width, p->shift, reg);
p = &mpll->n2;
reg = readl(mpll->base + p->reg_off);
n2 = PARM_GET(p->width, p->shift, reg);
rate = (parent_rate * SDM_MAX) / ((SDM_MAX * n2) + sdm);
return rate;
}
const struct clk_ops meson_clk_mpll_ro_ops = {
.recalc_rate = mpll_recalc_rate,
};