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

1 files changed, 158 insertions, 0 deletions

diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
new file mode 100644
index 000000000000..cbf33ef5faa9
--- /dev/null
+++ b/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,
+};