diff options
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_nkmp.c')
| -rw-r--r-- | drivers/clk/sunxi-ng/ccu_nkmp.c | 232 |
1 files changed, 232 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 000000000..bda87b38c --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nkmp.c @@ -0,0 +1,232 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2016 Maxime Ripard + * Maxime Ripard <maxime.ripard@free-electrons.com> + */ + +#include <linux/clk-provider.h> +#include <linux/io.h> + +#include "ccu_gate.h" +#include "ccu_nkmp.h" + +struct _ccu_nkmp { + unsigned long n, min_n, max_n; + unsigned long k, min_k, max_k; + unsigned long m, min_m, max_m; + unsigned long p, min_p, max_p; +}; + +static unsigned long ccu_nkmp_calc_rate(unsigned long parent, + unsigned long n, unsigned long k, + unsigned long m, unsigned long p) +{ + u64 rate = parent; + + rate *= n * k; + do_div(rate, m * p); + + return rate; +} + +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 = nkmp->min_k; _k <= nkmp->max_k; _k++) { + for (_n = nkmp->min_n; _n <= nkmp->max_n; _n++) { + for (_m = nkmp->min_m; _m <= nkmp->max_m; _m++) { + for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) { + unsigned long tmp_rate; + + tmp_rate = ccu_nkmp_calc_rate(parent, + _n, _k, + _m, _p); + + 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, rate; + u32 reg; + + reg = readl(nkmp->common.base + nkmp->common.reg); + + n = reg >> nkmp->n.shift; + n &= (1 << nkmp->n.width) - 1; + n += nkmp->n.offset; + if (!n) + n++; + + k = reg >> nkmp->k.shift; + k &= (1 << nkmp->k.width) - 1; + k += nkmp->k.offset; + if (!k) + k++; + + m = reg >> nkmp->m.shift; + m &= (1 << nkmp->m.width) - 1; + m += nkmp->m.offset; + if (!m) + m++; + + p = reg >> nkmp->p.shift; + p &= (1 << nkmp->p.width) - 1; + + rate = ccu_nkmp_calc_rate(parent_rate, n, k, m, 1 << p); + if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate /= nkmp->fixed_post_div; + + return rate; +} + +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; + + if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate *= nkmp->fixed_post_div; + + if (nkmp->max_rate && rate > nkmp->max_rate) { + rate = nkmp->max_rate; + if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate /= nkmp->fixed_post_div; + return rate; + } + + _nkmp.min_n = nkmp->n.min ?: 1; + _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; + _nkmp.min_k = nkmp->k.min ?: 1; + _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; + _nkmp.min_m = 1; + _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; + _nkmp.min_p = 1; + _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); + + ccu_nkmp_find_best(*parent_rate, rate, &_nkmp); + + rate = ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k, + _nkmp.m, _nkmp.p); + if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate = rate / nkmp->fixed_post_div; + + return rate; +} + +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); + u32 n_mask = 0, k_mask = 0, m_mask = 0, p_mask = 0; + struct _ccu_nkmp _nkmp; + unsigned long flags; + u32 reg; + + if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV) + rate = rate * nkmp->fixed_post_div; + + _nkmp.min_n = nkmp->n.min ?: 1; + _nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width; + _nkmp.min_k = nkmp->k.min ?: 1; + _nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width; + _nkmp.min_m = 1; + _nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width; + _nkmp.min_p = 1; + _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1); + + ccu_nkmp_find_best(parent_rate, rate, &_nkmp); + + /* + * If width is 0, GENMASK() macro may not generate expected mask (0) + * as it falls under undefined behaviour by C standard due to shifts + * which are equal or greater than width of left operand. This can + * be easily avoided by explicitly checking if width is 0. + */ + if (nkmp->n.width) + n_mask = GENMASK(nkmp->n.width + nkmp->n.shift - 1, + nkmp->n.shift); + if (nkmp->k.width) + k_mask = GENMASK(nkmp->k.width + nkmp->k.shift - 1, + nkmp->k.shift); + if (nkmp->m.width) + m_mask = GENMASK(nkmp->m.width + nkmp->m.shift - 1, + nkmp->m.shift); + if (nkmp->p.width) + p_mask = GENMASK(nkmp->p.width + nkmp->p.shift - 1, + nkmp->p.shift); + + spin_lock_irqsave(nkmp->common.lock, flags); + + reg = readl(nkmp->common.base + nkmp->common.reg); + reg &= ~(n_mask | k_mask | m_mask | p_mask); + + reg |= ((_nkmp.n - nkmp->n.offset) << nkmp->n.shift) & n_mask; + reg |= ((_nkmp.k - nkmp->k.offset) << nkmp->k.shift) & k_mask; + reg |= ((_nkmp.m - nkmp->m.offset) << nkmp->m.shift) & m_mask; + reg |= (ilog2(_nkmp.p) << nkmp->p.shift) & p_mask; + + 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, +}; |