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path: root/drivers/clk/sunxi-ng/ccu_nk.c
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-rw-r--r--drivers/clk/sunxi-ng/ccu_nk.c160
1 files changed, 160 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..c4fb82af9
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nk.c
@@ -0,0 +1,160 @@
+// 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_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,
+};
+EXPORT_SYMBOL_NS_GPL(ccu_nk_ops, SUNXI_CCU);