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- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * Copyright (C) 2016 Maxime Ripard
- * Maxime Ripard <[email protected]>
- */
- #include <linux/clk-provider.h>
- #include <linux/io.h>
- #include "ccu_gate.h"
- #include "ccu_nk.h"
- struct _ccu_nk {
- unsigned long n, min_n, max_n;
- unsigned long k, min_k, max_k;
- };
- static void ccu_nk_find_best(unsigned long parent, unsigned long rate,
- struct _ccu_nk *nk)
- {
- unsigned long best_rate = 0;
- unsigned int best_k = 0, best_n = 0;
- unsigned int _k, _n;
- for (_k = nk->min_k; _k <= nk->max_k; _k++) {
- for (_n = nk->min_n; _n <= nk->max_n; _n++) {
- unsigned long tmp_rate = parent * _n * _k;
- if (tmp_rate > rate)
- continue;
- if ((rate - tmp_rate) < (rate - best_rate)) {
- best_rate = tmp_rate;
- best_k = _k;
- best_n = _n;
- }
- }
- }
- nk->k = best_k;
- nk->n = best_n;
- }
- static void ccu_nk_disable(struct clk_hw *hw)
- {
- struct ccu_nk *nk = hw_to_ccu_nk(hw);
- return ccu_gate_helper_disable(&nk->common, nk->enable);
- }
- static int ccu_nk_enable(struct clk_hw *hw)
- {
- struct ccu_nk *nk = hw_to_ccu_nk(hw);
- return ccu_gate_helper_enable(&nk->common, nk->enable);
- }
- static int ccu_nk_is_enabled(struct clk_hw *hw)
- {
- struct ccu_nk *nk = hw_to_ccu_nk(hw);
- return ccu_gate_helper_is_enabled(&nk->common, nk->enable);
- }
- static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
- unsigned long parent_rate)
- {
- struct ccu_nk *nk = hw_to_ccu_nk(hw);
- unsigned long rate, n, k;
- u32 reg;
- reg = readl(nk->common.base + nk->common.reg);
- n = reg >> nk->n.shift;
- n &= (1 << nk->n.width) - 1;
- n += nk->n.offset;
- if (!n)
- n++;
- k = reg >> nk->k.shift;
- k &= (1 << nk->k.width) - 1;
- k += nk->k.offset;
- if (!k)
- k++;
- rate = parent_rate * n * k;
- if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nk->fixed_post_div;
- return rate;
- }
- static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long *parent_rate)
- {
- struct ccu_nk *nk = hw_to_ccu_nk(hw);
- struct _ccu_nk _nk;
- if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate *= nk->fixed_post_div;
- _nk.min_n = nk->n.min ?: 1;
- _nk.max_n = nk->n.max ?: 1 << nk->n.width;
- _nk.min_k = nk->k.min ?: 1;
- _nk.max_k = nk->k.max ?: 1 << nk->k.width;
- ccu_nk_find_best(*parent_rate, rate, &_nk);
- rate = *parent_rate * _nk.n * _nk.k;
- if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate = rate / nk->fixed_post_div;
- return rate;
- }
- static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long parent_rate)
- {
- struct ccu_nk *nk = hw_to_ccu_nk(hw);
- unsigned long flags;
- struct _ccu_nk _nk;
- u32 reg;
- if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate = rate * nk->fixed_post_div;
- _nk.min_n = nk->n.min ?: 1;
- _nk.max_n = nk->n.max ?: 1 << nk->n.width;
- _nk.min_k = nk->k.min ?: 1;
- _nk.max_k = nk->k.max ?: 1 << nk->k.width;
- ccu_nk_find_best(parent_rate, rate, &_nk);
- spin_lock_irqsave(nk->common.lock, flags);
- reg = readl(nk->common.base + nk->common.reg);
- reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift);
- reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
- reg |= (_nk.k - nk->k.offset) << nk->k.shift;
- reg |= (_nk.n - nk->n.offset) << nk->n.shift;
- writel(reg, nk->common.base + nk->common.reg);
- spin_unlock_irqrestore(nk->common.lock, flags);
- ccu_helper_wait_for_lock(&nk->common, nk->lock);
- return 0;
- }
- const struct clk_ops ccu_nk_ops = {
- .disable = ccu_nk_disable,
- .enable = ccu_nk_enable,
- .is_enabled = ccu_nk_is_enabled,
- .recalc_rate = ccu_nk_recalc_rate,
- .round_rate = ccu_nk_round_rate,
- .set_rate = ccu_nk_set_rate,
- };
- EXPORT_SYMBOL_NS_GPL(ccu_nk_ops, SUNXI_CCU);
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