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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/sunxi-ng/ccu_nkm.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c new file mode 100644 index 000000000..841840e35 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nkm.c @@ -0,0 +1,211 @@ +/* + * Copyright (C) 2016 Maxime Ripard + * Maxime Ripard <maxime.ripard@free-electrons.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + */ + +#include <linux/clk-provider.h> + +#include "ccu_gate.h" +#include "ccu_nkm.h" + +struct _ccu_nkm { + unsigned long n, min_n, max_n; + unsigned long k, min_k, max_k; + unsigned long m, min_m, max_m; +}; + +static void ccu_nkm_find_best(unsigned long parent, unsigned long rate, + struct _ccu_nkm *nkm) +{ + unsigned long best_rate = 0; + unsigned long best_n = 0, best_k = 0, best_m = 0; + unsigned long _n, _k, _m; + + for (_k = nkm->min_k; _k <= nkm->max_k; _k++) { + for (_n = nkm->min_n; _n <= nkm->max_n; _n++) { + for (_m = nkm->min_m; _m <= nkm->max_m; _m++) { + unsigned long tmp_rate; + + tmp_rate = parent * _n * _k / _m; + + if (tmp_rate > rate) + continue; + if ((rate - tmp_rate) < (rate - best_rate)) { + best_rate = tmp_rate; + best_n = _n; + best_k = _k; + best_m = _m; + } + } + } + } + + nkm->n = best_n; + nkm->k = best_k; + nkm->m = best_m; +} + +static void ccu_nkm_disable(struct clk_hw *hw) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_gate_helper_disable(&nkm->common, nkm->enable); +} + +static int ccu_nkm_enable(struct clk_hw *hw) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_gate_helper_enable(&nkm->common, nkm->enable); +} + +static int ccu_nkm_is_enabled(struct clk_hw *hw) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable); +} + +static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + unsigned long n, m, k, rate; + u32 reg; + + reg = readl(nkm->common.base + nkm->common.reg); + + n = reg >> nkm->n.shift; + n &= (1 << nkm->n.width) - 1; + n += nkm->n.offset; + if (!n) + n++; + + k = reg >> nkm->k.shift; + k &= (1 << nkm->k.width) - 1; + k += nkm->k.offset; + if (!k) + k++; + + m = reg >> nkm->m.shift; + m &= (1 << nkm->m.width) - 1; + m += nkm->m.offset; + if (!m) + m++; + + rate = parent_rate * n * k / m; + + if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate /= nkm->fixed_post_div; + + return rate; +} + +static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux, + struct clk_hw *hw, + unsigned long *parent_rate, + unsigned long rate, + void *data) +{ + struct ccu_nkm *nkm = data; + struct _ccu_nkm _nkm; + + _nkm.min_n = nkm->n.min ?: 1; + _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width; + _nkm.min_k = nkm->k.min ?: 1; + _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width; + _nkm.min_m = 1; + _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width; + + if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate *= nkm->fixed_post_div; + + ccu_nkm_find_best(*parent_rate, rate, &_nkm); + + rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m; + + if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate /= nkm->fixed_post_div; + + return rate; +} + +static int ccu_nkm_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux, + req, ccu_nkm_round_rate, nkm); +} + +static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + struct _ccu_nkm _nkm; + unsigned long flags; + u32 reg; + + if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate *= nkm->fixed_post_div; + + _nkm.min_n = nkm->n.min ?: 1; + _nkm.max_n = nkm->n.max ?: 1 << nkm->n.width; + _nkm.min_k = nkm->k.min ?: 1; + _nkm.max_k = nkm->k.max ?: 1 << nkm->k.width; + _nkm.min_m = 1; + _nkm.max_m = nkm->m.max ?: 1 << nkm->m.width; + + ccu_nkm_find_best(parent_rate, rate, &_nkm); + + spin_lock_irqsave(nkm->common.lock, flags); + + reg = readl(nkm->common.base + nkm->common.reg); + reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift); + reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift); + reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift); + + reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift; + reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift; + reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift; + writel(reg, nkm->common.base + nkm->common.reg); + + spin_unlock_irqrestore(nkm->common.lock, flags); + + ccu_helper_wait_for_lock(&nkm->common, nkm->lock); + + return 0; +} + +static u8 ccu_nkm_get_parent(struct clk_hw *hw) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux); +} + +static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index) +{ + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw); + + return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index); +} + +const struct clk_ops ccu_nkm_ops = { + .disable = ccu_nkm_disable, + .enable = ccu_nkm_enable, + .is_enabled = ccu_nkm_is_enabled, + + .get_parent = ccu_nkm_get_parent, + .set_parent = ccu_nkm_set_parent, + + .determine_rate = ccu_nkm_determine_rate, + .recalc_rate = ccu_nkm_recalc_rate, + .set_rate = ccu_nkm_set_rate, +}; 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