diff options
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_nkmp.c')
| -rw-r--r-- | drivers/clk/sunxi-ng/ccu_nkmp.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c new file mode 100644 index 000000000000..9f2b98e19dc9 --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nkmp.c @@ -0,0 +1,167 @@ +/* + * 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_nkmp.h" + +struct _ccu_nkmp { + unsigned long n, max_n; + unsigned long k, max_k; + unsigned long m, max_m; + unsigned long p, max_p; +}; + +static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate, + struct _ccu_nkmp *nkmp) +{ + unsigned long best_rate = 0; + unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0; + unsigned long _n, _k, _m, _p; + + for (_k = 1; _k <= nkmp->max_k; _k++) { + for (_p = 0; _p <= nkmp->max_p; _p++) { + unsigned long tmp_rate; + + rational_best_approximation(rate / _k, parent >> _p, + nkmp->max_n, nkmp->max_m, + &_n, &_m); + + tmp_rate = (parent * _n * _k >> _p) / _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; + best_p = _p; + } + } + } + + nkmp->n = best_n; + nkmp->k = best_k; + nkmp->m = best_m; + nkmp->p = best_p; +} + +static void ccu_nkmp_disable(struct clk_hw *hw) +{ + struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); + + return ccu_gate_helper_disable(&nkmp->common, nkmp->enable); +} + +static int ccu_nkmp_enable(struct clk_hw *hw) +{ + struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); + + return ccu_gate_helper_enable(&nkmp->common, nkmp->enable); +} + +static int ccu_nkmp_is_enabled(struct clk_hw *hw) +{ + struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); + + return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable); +} + +static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); + unsigned long n, m, k, p; + u32 reg; + + reg = readl(nkmp->common.base + nkmp->common.reg); + + n = reg >> nkmp->n.shift; + n &= (1 << nkmp->n.width) - 1; + + k = reg >> nkmp->k.shift; + k &= (1 << nkmp->k.width) - 1; + + m = reg >> nkmp->m.shift; + m &= (1 << nkmp->m.width) - 1; + + p = reg >> nkmp->p.shift; + p &= (1 << nkmp->p.width) - 1; + + return (parent_rate * (n + 1) * (k + 1) >> p) / (m + 1); +} + +static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); + struct _ccu_nkmp _nkmp; + + _nkmp.max_n = 1 << nkmp->n.width; + _nkmp.max_k = 1 << nkmp->k.width; + _nkmp.max_m = 1 << nkmp->m.width; + _nkmp.max_p = (1 << nkmp->p.width) - 1; + + ccu_nkmp_find_best(*parent_rate, rate, + &_nkmp); + + return (*parent_rate * _nkmp.n * _nkmp.k >> _nkmp.p) / _nkmp.m; +} + +static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw); + struct _ccu_nkmp _nkmp; + unsigned long flags; + u32 reg; + + _nkmp.max_n = 1 << nkmp->n.width; + _nkmp.max_k = 1 << nkmp->k.width; + _nkmp.max_m = 1 << nkmp->m.width; + _nkmp.max_p = (1 << nkmp->p.width) - 1; + + ccu_nkmp_find_best(parent_rate, rate, &_nkmp); + + spin_lock_irqsave(nkmp->common.lock, flags); + + reg = readl(nkmp->common.base + nkmp->common.reg); + reg &= ~GENMASK(nkmp->n.width + nkmp->n.shift - 1, nkmp->n.shift); + reg &= ~GENMASK(nkmp->k.width + nkmp->k.shift - 1, nkmp->k.shift); + reg &= ~GENMASK(nkmp->m.width + nkmp->m.shift - 1, nkmp->m.shift); + reg &= ~GENMASK(nkmp->p.width + nkmp->p.shift - 1, nkmp->p.shift); + + reg |= (_nkmp.n - 1) << nkmp->n.shift; + reg |= (_nkmp.k - 1) << nkmp->k.shift; + reg |= (_nkmp.m - 1) << nkmp->m.shift; + reg |= _nkmp.p << nkmp->p.shift; + + writel(reg, nkmp->common.base + nkmp->common.reg); + + spin_unlock_irqrestore(nkmp->common.lock, flags); + + ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock); + + return 0; +} + +const struct clk_ops ccu_nkmp_ops = { + .disable = ccu_nkmp_disable, + .enable = ccu_nkmp_enable, + .is_enabled = ccu_nkmp_is_enabled, + + .recalc_rate = ccu_nkmp_recalc_rate, + .round_rate = ccu_nkmp_round_rate, + .set_rate = ccu_nkmp_set_rate, +}; |