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path: root/drivers/clk/sunxi-ng/ccu_nkmp.c
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-rw-r--r--drivers/clk/sunxi-ng/ccu_nkmp.c233
1 files changed, 233 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 0000000000..99359a0689
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
@@ -0,0 +1,233 @@
+// 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 unsigned long 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;
+
+ return best_rate;
+}
+
+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);
+
+ rate = ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);
+
+ 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,
+};
+EXPORT_SYMBOL_NS_GPL(ccu_nkmp_ops, SUNXI_CCU);