clk: sunxi-ng: Add M-P factor clock support

Introduce support for the clocks that combine a linear divider and a
power-of-two based one.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-9-maxime.ripard@free-electrons.com

drivers/clk/sunxi-ng/Kconfig

@@ -22,4 +22,11 @@ config SUNXI_CCU_MUX
 config SUNXI_CCU_PHASE
 	bool
 
+# Multi-factor clocks
+
+config SUNXI_CCU_MP
+	bool
+	select SUNXI_CCU_GATE
+	select SUNXI_CCU_MUX
+
 endif

drivers/clk/sunxi-ng/Makefile

@@ -8,3 +8,6 @@ obj-$(CONFIG_SUNXI_CCU_FRAC)	+= ccu_frac.o
 obj-$(CONFIG_SUNXI_CCU_GATE)	+= ccu_gate.o
 obj-$(CONFIG_SUNXI_CCU_MUX)	+= ccu_mux.o
 obj-$(CONFIG_SUNXI_CCU_PHASE)	+= ccu_phase.o
+
+# Multi-factor clocks
+obj-$(CONFIG_SUNXI_CCU_MP)	+= ccu_mp.o

drivers/clk/sunxi-ng/ccu_mp.c

@@ -0,0 +1,158 @@
+/*
+ * 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 "ccu_gate.h"
+#include "ccu_mp.h"
+
+static void ccu_mp_find_best(unsigned long parent, unsigned long rate,
+			     unsigned int max_m, unsigned int max_p,
+			     unsigned int *m, unsigned int *p)
+{
+	unsigned long best_rate = 0;
+	unsigned int best_m = 0, best_p = 0;
+	unsigned int _m, _p;
+
+	for (_p = 0; _p <= max_p; _p++) {
+		for (_m = 1; _m <= max_m; _m++) {
+			unsigned long tmp_rate = (parent >> _p) / _m;
+
+			if (tmp_rate > rate)
+				continue;
+
+			if ((rate - tmp_rate) < (rate - best_rate)) {
+				best_rate = tmp_rate;
+				best_m = _m;
+				best_p = _p;
+			}
+		}
+	}
+
+	*m = best_m;
+	*p = best_p;
+}
+
+static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux,
+				       unsigned long parent_rate,
+				       unsigned long rate,
+				       void *data)
+{
+	struct ccu_mp *cmp = data;
+	unsigned int m, p;
+
+	ccu_mp_find_best(parent_rate, rate,
+			 1 << cmp->m.width, (1 << cmp->p.width) - 1,
+			 &m, &p);
+
+	return (parent_rate >> p) / m;
+}
+
+static void ccu_mp_disable(struct clk_hw *hw)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+	return ccu_gate_helper_disable(&cmp->common, cmp->enable);
+}
+
+static int ccu_mp_enable(struct clk_hw *hw)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+	return ccu_gate_helper_enable(&cmp->common, cmp->enable);
+}
+
+static int ccu_mp_is_enabled(struct clk_hw *hw)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+	return ccu_gate_helper_is_enabled(&cmp->common, cmp->enable);
+}
+
+static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
+					unsigned long parent_rate)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+	unsigned int m, p;
+	u32 reg;
+
+	reg = readl(cmp->common.base + cmp->common.reg);
+
+	m = reg >> cmp->m.shift;
+	m &= (1 << cmp->m.width) - 1;
+
+	p = reg >> cmp->p.shift;
+	p &= (1 << cmp->p.width) - 1;
+
+	return (parent_rate >> p) / (m + 1);
+}
+
+static int ccu_mp_determine_rate(struct clk_hw *hw,
+				 struct clk_rate_request *req)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+	return ccu_mux_helper_determine_rate(&cmp->common, &cmp->mux,
+					     req, ccu_mp_round_rate, cmp);
+}
+
+static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate,
+			   unsigned long parent_rate)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+	unsigned long flags;
+	unsigned int m, p;
+	u32 reg;
+
+	ccu_mp_find_best(parent_rate, rate,
+			 1 << cmp->m.width, (1 << cmp->p.width) - 1,
+			 &m, &p);
+
+
+	spin_lock_irqsave(cmp->common.lock, flags);
+
+	reg = readl(cmp->common.base + cmp->common.reg);
+	reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift);
+	reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift);
+
+	writel(reg | (p << cmp->p.shift) | ((m - 1) << cmp->m.shift),
+	       cmp->common.base + cmp->common.reg);
+
+	spin_unlock_irqrestore(cmp->common.lock, flags);
+
+	return 0;
+}
+
+static u8 ccu_mp_get_parent(struct clk_hw *hw)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+	return ccu_mux_helper_get_parent(&cmp->common, &cmp->mux);
+}
+
+static int ccu_mp_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct ccu_mp *cmp = hw_to_ccu_mp(hw);
+
+	return ccu_mux_helper_set_parent(&cmp->common, &cmp->mux, index);
+}
+
+const struct clk_ops ccu_mp_ops = {
+	.disable	= ccu_mp_disable,
+	.enable		= ccu_mp_enable,
+	.is_enabled	= ccu_mp_is_enabled,
+
+	.get_parent	= ccu_mp_get_parent,
+	.set_parent	= ccu_mp_set_parent,
+
+	.determine_rate	= ccu_mp_determine_rate,
+	.recalc_rate	= ccu_mp_recalc_rate,
+	.set_rate	= ccu_mp_set_rate,
+};

drivers/clk/sunxi-ng/ccu_mp.h

@@ -0,0 +1,77 @@
+/*
+ * 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_MP_H_
+#define _CCU_MP_H_
+
+#include <linux/clk-provider.h>
+
+#include "ccu_common.h"
+#include "ccu_div.h"
+#include "ccu_mult.h"
+#include "ccu_mux.h"
+
+/*
+ * struct ccu_mp - Definition of an M-P clock
+ *
+ * Clocks based on the formula parent >> P / M
+ */
+struct ccu_mp {
+	u32			enable;
+
+	struct _ccu_div		m;
+	struct _ccu_div		p;
+	struct ccu_mux_internal	mux;
+	struct ccu_common	common;
+};
+
+#define SUNXI_CCU_MP_WITH_MUX_GATE(_struct, _name, _parents, _reg,	\
+				   _mshift, _mwidth,			\
+				   _pshift, _pwidth,			\
+				   _muxshift, _muxwidth,		\
+				   _gate, _flags)			\
+	struct ccu_mp _struct = {					\
+		.enable	= _gate,					\
+		.m	= _SUNXI_CCU_DIV(_mshift, _mwidth),		\
+		.p	= _SUNXI_CCU_DIV(_pshift, _pwidth),		\
+		.mux	= SUNXI_CLK_MUX(_muxshift, _muxwidth),		\
+		.common	= {						\
+			.reg		= _reg,				\
+			.hw.init	= CLK_HW_INIT_PARENTS(_name,	\
+							      _parents, \
+							      &ccu_mp_ops, \
+							      _flags),	\
+		}							\
+	}
+
+#define SUNXI_CCU_MP_WITH_MUX(_struct, _name, _parents, _reg,		\
+			      _mshift, _mwidth,				\
+			      _pshift, _pwidth,				\
+			      _muxshift, _muxwidth,			\
+			      _flags)					\
+	SUNXI_CCU_MP_WITH_MUX_GATE(_struct, _name, _parents, _reg,	\
+				   _mshift, _mwidth,			\
+				   _pshift, _pwidth,			\
+				   _muxshift, _muxwidth,		\
+				   0, _flags)
+
+static inline struct ccu_mp *hw_to_ccu_mp(struct clk_hw *hw)
+{
+	struct ccu_common *common = hw_to_ccu_common(hw);
+
+	return container_of(common, struct ccu_mp, common);
+}
+
+extern const struct clk_ops ccu_mp_ops;
+
+#endif /* _CCU_MP_H_ */