diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
commit | d0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch) | |
tree | 7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /drivers/clk/sunxi-ng/ccu_nk.c | |
parent | e914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff) |
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_nk.c')
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_nk.c | 147 |
1 files changed, 147 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..d6fafb397 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nk.c @@ -0,0 +1,147 @@ +/* + * 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 <linux/rational.h> + +#include "ccu_gate.h" +#include "ccu_nk.h" + +static void ccu_nk_find_best(unsigned long parent, unsigned long rate, + unsigned int max_n, unsigned int max_k, + unsigned int *n, unsigned int *k) +{ + unsigned long best_rate = 0; + unsigned int best_k = 0, best_n = 0; + unsigned int _k, _n; + + for (_k = 1; _k <= max_k; _k++) { + for (_n = 1; _n <= 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; + } + } + } + + *k = best_k; + *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; + + k = reg >> nk->k.shift; + k &= (1 << nk->k.width) - 1; + + rate = parent_rate * (n + 1) * (k + 1); + + 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); + unsigned int n, k; + + if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate *= nk->fixed_post_div; + + ccu_nk_find_best(*parent_rate, rate, + 1 << nk->n.width, 1 << nk->k.width, + &n, &k); + + rate = *parent_rate * n * 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; + unsigned int n, k; + u32 reg; + + if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate = rate * nk->fixed_post_div; + + ccu_nk_find_best(parent_rate, rate, + 1 << nk->n.width, 1 << nk->k.width, + &n, &k); + + 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); + + writel(reg | ((k - 1) << nk->k.shift) | ((n - 1) << nk->n.shift), + 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, +}; |