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240 lines
5.7 KiB
240 lines
5.7 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Copyright (C) 2016 Maxime Ripard |
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* Maxime Ripard <[email protected]> |
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*/ |
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#include <linux/clk-provider.h> |
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#include <linux/io.h> |
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#include "ccu_frac.h" |
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#include "ccu_gate.h" |
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#include "ccu_nm.h" |
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struct _ccu_nm { |
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unsigned long n, min_n, max_n; |
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unsigned long m, min_m, max_m; |
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}; |
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static unsigned long ccu_nm_calc_rate(unsigned long parent, |
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unsigned long n, unsigned long m) |
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{ |
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u64 rate = parent; |
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rate *= n; |
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do_div(rate, m); |
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return rate; |
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} |
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static void ccu_nm_find_best(unsigned long parent, unsigned long rate, |
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struct _ccu_nm *nm) |
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{ |
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unsigned long best_rate = 0; |
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unsigned long best_n = 0, best_m = 0; |
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unsigned long _n, _m; |
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for (_n = nm->min_n; _n <= nm->max_n; _n++) { |
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for (_m = nm->min_m; _m <= nm->max_m; _m++) { |
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unsigned long tmp_rate = ccu_nm_calc_rate(parent, |
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_n, _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_m = _m; |
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} |
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} |
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} |
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nm->n = best_n; |
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nm->m = best_m; |
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} |
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static void ccu_nm_disable(struct clk_hw *hw) |
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{ |
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struct ccu_nm *nm = hw_to_ccu_nm(hw); |
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return ccu_gate_helper_disable(&nm->common, nm->enable); |
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} |
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static int ccu_nm_enable(struct clk_hw *hw) |
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{ |
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struct ccu_nm *nm = hw_to_ccu_nm(hw); |
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return ccu_gate_helper_enable(&nm->common, nm->enable); |
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} |
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static int ccu_nm_is_enabled(struct clk_hw *hw) |
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{ |
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struct ccu_nm *nm = hw_to_ccu_nm(hw); |
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return ccu_gate_helper_is_enabled(&nm->common, nm->enable); |
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} |
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static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw, |
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unsigned long parent_rate) |
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{ |
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struct ccu_nm *nm = hw_to_ccu_nm(hw); |
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unsigned long rate; |
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unsigned long n, m; |
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u32 reg; |
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if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac)) { |
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rate = ccu_frac_helper_read_rate(&nm->common, &nm->frac); |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate /= nm->fixed_post_div; |
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return rate; |
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} |
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reg = readl(nm->common.base + nm->common.reg); |
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n = reg >> nm->n.shift; |
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n &= (1 << nm->n.width) - 1; |
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n += nm->n.offset; |
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if (!n) |
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n++; |
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m = reg >> nm->m.shift; |
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m &= (1 << nm->m.width) - 1; |
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m += nm->m.offset; |
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if (!m) |
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m++; |
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if (ccu_sdm_helper_is_enabled(&nm->common, &nm->sdm)) |
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rate = ccu_sdm_helper_read_rate(&nm->common, &nm->sdm, m, n); |
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else |
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rate = ccu_nm_calc_rate(parent_rate, n, m); |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate /= nm->fixed_post_div; |
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return rate; |
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} |
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static long ccu_nm_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_nm *nm = hw_to_ccu_nm(hw); |
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struct _ccu_nm _nm; |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate *= nm->fixed_post_div; |
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if (rate < nm->min_rate) { |
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rate = nm->min_rate; |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate /= nm->fixed_post_div; |
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return rate; |
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} |
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if (nm->max_rate && rate > nm->max_rate) { |
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rate = nm->max_rate; |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate /= nm->fixed_post_div; |
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return rate; |
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} |
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if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) { |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate /= nm->fixed_post_div; |
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return rate; |
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} |
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if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) { |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate /= nm->fixed_post_div; |
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return rate; |
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} |
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_nm.min_n = nm->n.min ?: 1; |
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_nm.max_n = nm->n.max ?: 1 << nm->n.width; |
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_nm.min_m = 1; |
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_nm.max_m = nm->m.max ?: 1 << nm->m.width; |
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ccu_nm_find_best(*parent_rate, rate, &_nm); |
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rate = ccu_nm_calc_rate(*parent_rate, _nm.n, _nm.m); |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate /= nm->fixed_post_div; |
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return rate; |
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} |
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static int ccu_nm_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_nm *nm = hw_to_ccu_nm(hw); |
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struct _ccu_nm _nm; |
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unsigned long flags; |
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u32 reg; |
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/* Adjust target rate according to post-dividers */ |
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if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) |
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rate = rate * nm->fixed_post_div; |
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if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) { |
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spin_lock_irqsave(nm->common.lock, flags); |
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/* most SoCs require M to be 0 if fractional mode is used */ |
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reg = readl(nm->common.base + nm->common.reg); |
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reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift); |
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writel(reg, nm->common.base + nm->common.reg); |
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spin_unlock_irqrestore(nm->common.lock, flags); |
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ccu_frac_helper_enable(&nm->common, &nm->frac); |
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return ccu_frac_helper_set_rate(&nm->common, &nm->frac, |
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rate, nm->lock); |
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} else { |
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ccu_frac_helper_disable(&nm->common, &nm->frac); |
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} |
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_nm.min_n = nm->n.min ?: 1; |
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_nm.max_n = nm->n.max ?: 1 << nm->n.width; |
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_nm.min_m = 1; |
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_nm.max_m = nm->m.max ?: 1 << nm->m.width; |
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if (ccu_sdm_helper_has_rate(&nm->common, &nm->sdm, rate)) { |
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ccu_sdm_helper_enable(&nm->common, &nm->sdm, rate); |
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/* Sigma delta modulation requires specific N and M factors */ |
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ccu_sdm_helper_get_factors(&nm->common, &nm->sdm, rate, |
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&_nm.m, &_nm.n); |
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} else { |
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ccu_sdm_helper_disable(&nm->common, &nm->sdm); |
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ccu_nm_find_best(parent_rate, rate, &_nm); |
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} |
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spin_lock_irqsave(nm->common.lock, flags); |
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reg = readl(nm->common.base + nm->common.reg); |
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reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift); |
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reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift); |
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reg |= (_nm.n - nm->n.offset) << nm->n.shift; |
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reg |= (_nm.m - nm->m.offset) << nm->m.shift; |
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writel(reg, nm->common.base + nm->common.reg); |
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spin_unlock_irqrestore(nm->common.lock, flags); |
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ccu_helper_wait_for_lock(&nm->common, nm->lock); |
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return 0; |
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} |
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const struct clk_ops ccu_nm_ops = { |
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.disable = ccu_nm_disable, |
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.enable = ccu_nm_enable, |
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.is_enabled = ccu_nm_is_enabled, |
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.recalc_rate = ccu_nm_recalc_rate, |
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.round_rate = ccu_nm_round_rate, |
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.set_rate = ccu_nm_set_rate, |
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};
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