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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_frac.h"
- #include "ccu_gate.h"
- #include "ccu_nm.h"
- struct _ccu_nm {
- unsigned long n, min_n, max_n;
- unsigned long m, min_m, max_m;
- };
- static unsigned long ccu_nm_calc_rate(unsigned long parent,
- unsigned long n, unsigned long m)
- {
- u64 rate = parent;
- rate *= n;
- do_div(rate, m);
- return rate;
- }
- static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
- struct _ccu_nm *nm)
- {
- unsigned long best_rate = 0;
- unsigned long best_n = 0, best_m = 0;
- unsigned long _n, _m;
- for (_n = nm->min_n; _n <= nm->max_n; _n++) {
- for (_m = nm->min_m; _m <= nm->max_m; _m++) {
- unsigned long tmp_rate = ccu_nm_calc_rate(parent,
- _n, _m);
- if (tmp_rate > rate)
- continue;
- if ((rate - tmp_rate) < (rate - best_rate)) {
- best_rate = tmp_rate;
- best_n = _n;
- best_m = _m;
- }
- }
- }
- nm->n = best_n;
- nm->m = best_m;
- }
- static void ccu_nm_disable(struct clk_hw *hw)
- {
- struct ccu_nm *nm = hw_to_ccu_nm(hw);
- return ccu_gate_helper_disable(&nm->common, nm->enable);
- }
- static int ccu_nm_enable(struct clk_hw *hw)
- {
- struct ccu_nm *nm = hw_to_ccu_nm(hw);
- return ccu_gate_helper_enable(&nm->common, nm->enable);
- }
- static int ccu_nm_is_enabled(struct clk_hw *hw)
- {
- struct ccu_nm *nm = hw_to_ccu_nm(hw);
- return ccu_gate_helper_is_enabled(&nm->common, nm->enable);
- }
- static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
- unsigned long parent_rate)
- {
- struct ccu_nm *nm = hw_to_ccu_nm(hw);
- unsigned long rate;
- unsigned long n, m;
- u32 reg;
- if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac)) {
- rate = ccu_frac_helper_read_rate(&nm->common, &nm->frac);
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nm->fixed_post_div;
- return rate;
- }
- reg = readl(nm->common.base + nm->common.reg);
- n = reg >> nm->n.shift;
- n &= (1 << nm->n.width) - 1;
- n += nm->n.offset;
- if (!n)
- n++;
- m = reg >> nm->m.shift;
- m &= (1 << nm->m.width) - 1;
- m += nm->m.offset;
- if (!m)
- m++;
- if (ccu_sdm_helper_is_enabled(&nm->common, &nm->sdm))
- rate = ccu_sdm_helper_read_rate(&nm->common, &nm->sdm, m, n);
- else
- rate = ccu_nm_calc_rate(parent_rate, n, m);
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nm->fixed_post_div;
- return rate;
- }
- static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long *parent_rate)
- {
- struct ccu_nm *nm = hw_to_ccu_nm(hw);
- struct _ccu_nm _nm;
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate *= nm->fixed_post_div;
- if (rate < nm->min_rate) {
- rate = nm->min_rate;
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nm->fixed_post_div;
- return rate;
- }
- if (nm->max_rate && rate > nm->max_rate) {
- rate = nm->max_rate;
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nm->fixed_post_div;
- return rate;
- }
- if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) {
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nm->fixed_post_div;
- return rate;
- }
- if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) {
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nm->fixed_post_div;
- return rate;
- }
- _nm.min_n = nm->n.min ?: 1;
- _nm.max_n = nm->n.max ?: 1 << nm->n.width;
- _nm.min_m = 1;
- _nm.max_m = nm->m.max ?: 1 << nm->m.width;
- ccu_nm_find_best(*parent_rate, rate, &_nm);
- rate = ccu_nm_calc_rate(*parent_rate, _nm.n, _nm.m);
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate /= nm->fixed_post_div;
- return rate;
- }
- static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long parent_rate)
- {
- struct ccu_nm *nm = hw_to_ccu_nm(hw);
- struct _ccu_nm _nm;
- unsigned long flags;
- u32 reg;
- /* Adjust target rate according to post-dividers */
- if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
- rate = rate * nm->fixed_post_div;
- if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) {
- spin_lock_irqsave(nm->common.lock, flags);
- /* most SoCs require M to be 0 if fractional mode is used */
- reg = readl(nm->common.base + nm->common.reg);
- reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
- writel(reg, nm->common.base + nm->common.reg);
- spin_unlock_irqrestore(nm->common.lock, flags);
- ccu_frac_helper_enable(&nm->common, &nm->frac);
- return ccu_frac_helper_set_rate(&nm->common, &nm->frac,
- rate, nm->lock);
- } else {
- ccu_frac_helper_disable(&nm->common, &nm->frac);
- }
- _nm.min_n = nm->n.min ?: 1;
- _nm.max_n = nm->n.max ?: 1 << nm->n.width;
- _nm.min_m = 1;
- _nm.max_m = nm->m.max ?: 1 << nm->m.width;
- if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) {
- ccu_sdm_helper_enable(&nm->common, &nm->sdm, rate);
- /* Sigma delta modulation requires specific N and M factors */
- ccu_sdm_helper_get_factors(&nm->common, &nm->sdm, rate,
- &_nm.m, &_nm.n);
- } else {
- ccu_sdm_helper_disable(&nm->common, &nm->sdm);
- ccu_nm_find_best(parent_rate, rate, &_nm);
- }
- spin_lock_irqsave(nm->common.lock, flags);
- reg = readl(nm->common.base + nm->common.reg);
- reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
- reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
- reg |= (_nm.n - nm->n.offset) << nm->n.shift;
- reg |= (_nm.m - nm->m.offset) << nm->m.shift;
- writel(reg, nm->common.base + nm->common.reg);
- spin_unlock_irqrestore(nm->common.lock, flags);
- ccu_helper_wait_for_lock(&nm->common, nm->lock);
- return 0;
- }
- const struct clk_ops ccu_nm_ops = {
- .disable = ccu_nm_disable,
- .enable = ccu_nm_enable,
- .is_enabled = ccu_nm_is_enabled,
- .recalc_rate = ccu_nm_recalc_rate,
- .round_rate = ccu_nm_round_rate,
- .set_rate = ccu_nm_set_rate,
- };
- EXPORT_SYMBOL_NS_GPL(ccu_nm_ops, SUNXI_CCU);
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