forked from Minki/linux
clk: sunxi-ng: Add N-K-M Factor clock
Introduce support for clocks that multiply and divide using two linear multipliers and one linear divider. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Michael Turquette <mturquette@baylibre.com> Link: lkml.kernel.org/r/20160629190535.11855-12-maxime.ripard@free-electrons.com
This commit is contained in:
Maxime Ripard
Michael Turquette
parent
6174a1e24b
commit
df6561e602
@ -28,6 +28,11 @@ config SUNXI_CCU_NK
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bool
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select SUNXI_CCU_GATE
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config SUNXI_CCU_NKM
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bool
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select RATIONAL
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select SUNXI_CCU_GATE
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config SUNXI_CCU_NM
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bool
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select RATIONAL
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@ -11,5 +11,6 @@ obj-$(CONFIG_SUNXI_CCU_PHASE) += ccu_phase.o
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# Multi-factor clocks
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obj-$(CONFIG_SUNXI_CCU_NK) += ccu_nk.o
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obj-$(CONFIG_SUNXI_CCU_NKM) += ccu_nkm.o
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obj-$(CONFIG_SUNXI_CCU_NM) += ccu_nm.o
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obj-$(CONFIG_SUNXI_CCU_MP) += ccu_mp.o
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153
drivers/clk/sunxi-ng/ccu_nkm.c
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153
drivers/clk/sunxi-ng/ccu_nkm.c
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@ -0,0 +1,153 @@
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/*
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* Copyright (C) 2016 Maxime Ripard
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*/
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#include <linux/clk-provider.h>
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#include <linux/rational.h>
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#include "ccu_gate.h"
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#include "ccu_nkm.h"
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struct _ccu_nkm {
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unsigned long n, max_n;
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unsigned long k, max_k;
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unsigned long m, max_m;
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};
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static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
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struct _ccu_nkm *nkm)
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{
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unsigned long best_rate = 0;
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unsigned long best_n = 0, best_k = 0, best_m = 0;
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unsigned long _n, _k, _m;
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for (_k = 1; _k <= nkm->max_k; _k++) {
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unsigned long tmp_rate;
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rational_best_approximation(rate / _k, parent,
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nkm->max_n, nkm->max_m, &_n, &_m);
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tmp_rate = parent * _n * _k / _m;
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if (tmp_rate > rate)
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continue;
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if ((rate - tmp_rate) < (rate - best_rate)) {
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best_rate = tmp_rate;
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best_n = _n;
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best_k = _k;
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best_m = _m;
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}
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}
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nkm->n = best_n;
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nkm->k = best_k;
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nkm->m = best_m;
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}
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static void ccu_nkm_disable(struct clk_hw *hw)
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{
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struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
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return ccu_gate_helper_disable(&nkm->common, nkm->enable);
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}
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static int ccu_nkm_enable(struct clk_hw *hw)
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{
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struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
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return ccu_gate_helper_enable(&nkm->common, nkm->enable);
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}
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static int ccu_nkm_is_enabled(struct clk_hw *hw)
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{
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struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
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return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
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}
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static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
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unsigned long n, m, k;
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u32 reg;
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reg = readl(nkm->common.base + nkm->common.reg);
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n = reg >> nkm->n.shift;
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n &= (1 << nkm->n.width) - 1;
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k = reg >> nkm->k.shift;
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k &= (1 << nkm->k.width) - 1;
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m = reg >> nkm->m.shift;
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m &= (1 << nkm->m.width) - 1;
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return parent_rate * (n + 1) * (k + 1) / (m + 1);
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}
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static long ccu_nkm_round_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long *parent_rate)
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{
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struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
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struct _ccu_nkm _nkm;
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_nkm.max_n = 1 << nkm->n.width;
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_nkm.max_k = 1 << nkm->k.width;
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_nkm.max_m = 1 << nkm->m.width;
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ccu_nkm_find_best(*parent_rate, rate, &_nkm);
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return *parent_rate * _nkm.n * _nkm.k / _nkm.m;
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}
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static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
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struct _ccu_nkm _nkm;
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unsigned long flags;
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u32 reg;
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_nkm.max_n = 1 << nkm->n.width;
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_nkm.max_k = 1 << nkm->k.width;
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_nkm.max_m = 1 << nkm->m.width;
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ccu_nkm_find_best(parent_rate, rate, &_nkm);
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spin_lock_irqsave(nkm->common.lock, flags);
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reg = readl(nkm->common.base + nkm->common.reg);
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reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
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reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
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reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
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reg |= (_nkm.n - 1) << nkm->n.shift;
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reg |= (_nkm.k - 1) << nkm->k.shift;
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reg |= (_nkm.m - 1) << nkm->m.shift;
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writel(reg, nkm->common.base + nkm->common.reg);
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spin_unlock_irqrestore(nkm->common.lock, flags);
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ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
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return 0;
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}
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const struct clk_ops ccu_nkm_ops = {
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.disable = ccu_nkm_disable,
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.enable = ccu_nkm_enable,
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.is_enabled = ccu_nkm_is_enabled,
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.recalc_rate = ccu_nkm_recalc_rate,
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.round_rate = ccu_nkm_round_rate,
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.set_rate = ccu_nkm_set_rate,
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};
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68
drivers/clk/sunxi-ng/ccu_nkm.h
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68
drivers/clk/sunxi-ng/ccu_nkm.h
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@ -0,0 +1,68 @@
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/*
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* Copyright (c) 2016 Maxime Ripard. All rights reserved.
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef _CCU_NKM_H_
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#define _CCU_NKM_H_
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#include <linux/clk-provider.h>
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#include "ccu_common.h"
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#include "ccu_div.h"
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#include "ccu_mult.h"
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/*
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* struct ccu_nkm - Definition of an N-K-M clock
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*
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* Clocks based on the formula parent * N * K / M
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*/
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struct ccu_nkm {
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u32 enable;
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u32 lock;
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struct _ccu_mult n;
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struct _ccu_mult k;
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struct _ccu_div m;
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struct ccu_common common;
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};
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#define SUNXI_CCU_NKM_WITH_GATE_LOCK(_struct, _name, _parent, _reg, \
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_nshift, _nwidth, \
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_kshift, _kwidth, \
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_mshift, _mwidth, \
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_gate, _lock, _flags) \
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struct ccu_nkm _struct = { \
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.enable = _gate, \
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.lock = _lock, \
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.k = _SUNXI_CCU_MULT(_kshift, _kwidth), \
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.n = _SUNXI_CCU_MULT(_nshift, _nwidth), \
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.m = _SUNXI_CCU_DIV(_mshift, _mwidth), \
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.common = { \
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.reg = _reg, \
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.hw.init = CLK_HW_INIT(_name, \
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_parent, \
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&ccu_nkm_ops, \
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_flags), \
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}, \
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}
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static inline struct ccu_nkm *hw_to_ccu_nkm(struct clk_hw *hw)
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{
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struct ccu_common *common = hw_to_ccu_common(hw);
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return container_of(common, struct ccu_nkm, common);
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}
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extern const struct clk_ops ccu_nkm_ops;
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#endif /* _CCU_NKM_H_ */
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