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path: root/drivers/clk/sunxi-ng/ccu_nkmp.c
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Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_nkmp.c')
-rw-r--r--drivers/clk/sunxi-ng/ccu_nkmp.c167
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,
+};