diff options
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_nk.c')
| -rw-r--r-- | drivers/clk/sunxi-ng/ccu_nk.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_nk.c b/drivers/clk/sunxi-ng/ccu_nk.c new file mode 100644 index 000000000..2485bda87 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nk.c @@ -0,0 +1,162 @@ +/* + * 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_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, +}; |