[PATCH 14/16] clk: sunxi-ng: Add N-K-M-P factor clock

Maxime Ripard
2016-05-08T20:01:49Z

Introduce support for clocks that use a combination of two linear
multipliers (N and K factors), one linear divider (M) and one power of two
divider (P).

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
drivers/clk/sunxi-ng/Makefile | 1 +
drivers/clk/sunxi-ng/ccu_nkmp.c | 157 ++++++++++++++++++++++++++++++++++++++++
drivers/clk/sunxi-ng/ccu_nkmp.h | 43 +++++++++++
3 files changed, 201 insertions(+)
create mode 100644 drivers/clk/sunxi-ng/ccu_nkmp.c
create mode 100644 drivers/clk/sunxi-ng/ccu_nkmp.h

diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
index 2bb8bc22e907..c794f57b6fb1 100644
--- a/drivers/clk/sunxi-ng/Makefile
+++ b/drivers/clk/sunxi-ng/Makefile
@@ -9,6 +9,7 @@ obj-y += ccu_mp.o
obj-y += ccu_mux.o
obj-y += ccu_nk.o
obj-y += ccu_nkm.o
+obj-y += ccu_nkmp.o
obj-y += ccu_nm.o
obj-y += ccu_p.o
obj-y += ccu_phase.o
diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c
new file mode 100644
index 000000000000..b7da00773cd6
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
@@ -0,0 +1,157 @@
+/*
+ * 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"
+
+void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
+ unsigned long max_n, unsigned long max_k,
+ unsigned long max_m, unsigned long max_p,
+ unsigned long *n, unsigned long *k,
+ unsigned long *m, unsigned long *p)
+{
+ 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 <= max_k; _k++) {
+ for (_p = 0; _p <= max_p; _p++) {
+ unsigned long tmp_rate;
+
+ rational_best_approximation(rate / _k, parent << _p,
+ max_n, 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;
+ }
+ }
+ }
+
+ *n = best_n;
+ *k = best_k;
+ *m = best_m;
+ *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);
+ unsigned long n, k, m, p;
+
+ ccu_nkmp_find_best(*parent_rate, rate,
+ 1 << nkmp->n.width, 1 << nkmp->k.width,
+ 1 << nkmp->m.width, (1 << nkmp->p.width) - 1,
+ &n, &k, &m, &p);
+
+ return (*parent_rate * n * k >> p) / 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);
+ unsigned long n, k, m, p;
+ unsigned long flags;
+ u32 reg;
+
+ ccu_nkmp_find_best(parent_rate, rate,
+ 1 << nkmp->n.width, 1 << nkmp->k.width,
+ 1 << nkmp->m.width, (1 << nkmp->p.width) - 1,
+ &n, &k, &m, &p);
+
+ spin_lock_irqsave(nkmp->common.lock, flags);
+
+ reg = readl(nkmp->common.base + nkmp->common.reg);
+ reg &= ~GENMASK(nkmp->n.width + nkmp->n.shift, nkmp->n.shift);
+ reg &= ~GENMASK(nkmp->k.width + nkmp->k.shift, nkmp->k.shift);
+ reg &= ~GENMASK(nkmp->m.width + nkmp->m.shift, nkmp->m.shift);
+ reg &= ~GENMASK(nkmp->p.width + nkmp->p.shift, nkmp->p.shift);
+
+ reg |= (n - 1) << nkmp->m.shift;
+ reg |= (k - 1) << nkmp->m.shift;
+ reg |= (m - 1) << nkmp->m.shift;
+ reg |= 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,
+};
diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.h b/drivers/clk/sunxi-ng/ccu_nkmp.h
new file mode 100644
index 000000000000..8a91f2c837a4
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2016 Maxime Ripard. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _CCU_NKMP_H_
+#define _CCU_NKMP_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_factor.h"
+#include "ccu_common.h"
+
+struct ccu_nkmp {
+ u32 enable;
+ u32 lock;
+
+ struct ccu_factor n;
+ struct ccu_factor k;
+ struct ccu_factor m;
+ struct ccu_factor p;
+
+ struct ccu_common common;
+};
+
+static inline struct ccu_nkmp *hw_to_ccu_nkmp(struct clk_hw *hw)
+{
+ struct ccu_common *common = hw_to_ccu_common(hw);
+
+ return container_of(common, struct ccu_nkmp, common);
+}
+
+extern const struct clk_ops ccu_nkmp_ops;
+
+#endif /* _CCU_NKMP_H_ */
--
2.8.2