1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
new file mode 100644
index 000000000..7d75da9a1
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_mux.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2016 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+
+#include "ccu_gate.h"
+#include "ccu_mux.h"
+
+static u16 ccu_mux_get_prediv(struct ccu_common *common,
+			      struct ccu_mux_internal *cm,
+			      int parent_index)
+{
+	u16 prediv = 1;
+	u32 reg;
+
+	if (!((common->features & CCU_FEATURE_FIXED_PREDIV) ||
+	      (common->features & CCU_FEATURE_VARIABLE_PREDIV) ||
+	      (common->features & CCU_FEATURE_ALL_PREDIV)))
+		return 1;
+
+	if (common->features & CCU_FEATURE_ALL_PREDIV)
+		return common->prediv;
+
+	reg = readl(common->base + common->reg);
+	if (parent_index < 0) {
+		parent_index = reg >> cm->shift;
+		parent_index &= (1 << cm->width) - 1;
+	}
+
+	if (common->features & CCU_FEATURE_FIXED_PREDIV) {
+		int i;
+
+		for (i = 0; i < cm->n_predivs; i++)
+			if (parent_index == cm->fixed_predivs[i].index)
+				prediv = cm->fixed_predivs[i].div;
+	}
+
+	if (common->features & CCU_FEATURE_VARIABLE_PREDIV) {
+		int i;
+
+		for (i = 0; i < cm->n_var_predivs; i++)
+			if (parent_index == cm->var_predivs[i].index) {
+				u8 div;
+
+				div = reg >> cm->var_predivs[i].shift;
+				div &= (1 << cm->var_predivs[i].width) - 1;
+				prediv = div + 1;
+			}
+	}
+
+	return prediv;
+}
+
+unsigned long ccu_mux_helper_apply_prediv(struct ccu_common *common,
+					  struct ccu_mux_internal *cm,
+					  int parent_index,
+					  unsigned long parent_rate)
+{
+	return parent_rate / ccu_mux_get_prediv(common, cm, parent_index);
+}
+
+static unsigned long ccu_mux_helper_unapply_prediv(struct ccu_common *common,
+					    struct ccu_mux_internal *cm,
+					    int parent_index,
+					    unsigned long parent_rate)
+{
+	return parent_rate * ccu_mux_get_prediv(common, cm, parent_index);
+}
+
+int ccu_mux_helper_determine_rate(struct ccu_common *common,
+				  struct ccu_mux_internal *cm,
+				  struct clk_rate_request *req,
+				  unsigned long (*round)(struct ccu_mux_internal *,
+							 struct clk_hw *,
+							 unsigned long *,
+							 unsigned long,
+							 void *),
+				  void *data)
+{
+	unsigned long best_parent_rate = 0, best_rate = 0;
+	struct clk_hw *best_parent, *hw = &common->hw;
+	unsigned int i;
+
+	if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) {
+		unsigned long adj_parent_rate;
+
+		best_parent = clk_hw_get_parent(hw);
+		best_parent_rate = clk_hw_get_rate(best_parent);
+		adj_parent_rate = ccu_mux_helper_apply_prediv(common, cm, -1,
+							      best_parent_rate);
+
+		best_rate = round(cm, best_parent, &adj_parent_rate,
+				  req->rate, data);
+
+		/*
+		 * adj_parent_rate might have been modified by our clock.
+		 * Unapply the pre-divider if there's one, and give
+		 * the actual frequency the parent needs to run at.
+		 */
+		best_parent_rate = ccu_mux_helper_unapply_prediv(common, cm, -1,
+								 adj_parent_rate);
+
+		goto out;
+	}
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		unsigned long tmp_rate, parent_rate;
+		struct clk_hw *parent;
+
+		parent = clk_hw_get_parent_by_index(hw, i);
+		if (!parent)
+			continue;
+
+		parent_rate = ccu_mux_helper_apply_prediv(common, cm, i,
+							  clk_hw_get_rate(parent));
+
+		tmp_rate = round(cm, parent, &parent_rate, req->rate, data);
+
+		/*
+		 * parent_rate might have been modified by our clock.
+		 * Unapply the pre-divider if there's one, and give
+		 * the actual frequency the parent needs to run at.
+		 */
+		parent_rate = ccu_mux_helper_unapply_prediv(common, cm, i,
+							    parent_rate);
+		if (tmp_rate == req->rate) {
+			best_parent = parent;
+			best_parent_rate = parent_rate;
+			best_rate = tmp_rate;
+			goto out;
+		}
+
+		if ((req->rate - tmp_rate) < (req->rate - best_rate)) {
+			best_rate = tmp_rate;
+			best_parent_rate = parent_rate;
+			best_parent = parent;
+		}
+	}
+
+	if (best_rate == 0)
+		return -EINVAL;
+
+out:
+	req->best_parent_hw = best_parent;
+	req->best_parent_rate = best_parent_rate;
+	req->rate = best_rate;
+	return 0;
+}
+
+u8 ccu_mux_helper_get_parent(struct ccu_common *common,
+			     struct ccu_mux_internal *cm)
+{
+	u32 reg;
+	u8 parent;
+
+	reg = readl(common->base + common->reg);
+	parent = reg >> cm->shift;
+	parent &= (1 << cm->width) - 1;
+
+	if (cm->table) {
+		int num_parents = clk_hw_get_num_parents(&common->hw);
+		int i;
+
+		for (i = 0; i < num_parents; i++)
+			if (cm->table[i] == parent)
+				return i;
+	}
+
+	return parent;
+}
+
+int ccu_mux_helper_set_parent(struct ccu_common *common,
+			      struct ccu_mux_internal *cm,
+			      u8 index)
+{
+	unsigned long flags;
+	u32 reg;
+
+	if (cm->table)
+		index = cm->table[index];
+
+	spin_lock_irqsave(common->lock, flags);
+
+	reg = readl(common->base + common->reg);
+	reg &= ~GENMASK(cm->width + cm->shift - 1, cm->shift);
+	writel(reg | (index << cm->shift), common->base + common->reg);
+
+	spin_unlock_irqrestore(common->lock, flags);
+
+	return 0;
+}
+
+static void ccu_mux_disable(struct clk_hw *hw)
+{
+	struct ccu_mux *cm = hw_to_ccu_mux(hw);
+
+	return ccu_gate_helper_disable(&cm->common, cm->enable);
+}
+
+static int ccu_mux_enable(struct clk_hw *hw)
+{
+	struct ccu_mux *cm = hw_to_ccu_mux(hw);
+
+	return ccu_gate_helper_enable(&cm->common, cm->enable);
+}
+
+static int ccu_mux_is_enabled(struct clk_hw *hw)
+{
+	struct ccu_mux *cm = hw_to_ccu_mux(hw);
+
+	return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
+}
+
+static u8 ccu_mux_get_parent(struct clk_hw *hw)
+{
+	struct ccu_mux *cm = hw_to_ccu_mux(hw);
+
+	return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
+}
+
+static int ccu_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct ccu_mux *cm = hw_to_ccu_mux(hw);
+
+	return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
+}
+
+static unsigned long ccu_mux_recalc_rate(struct clk_hw *hw,
+					 unsigned long parent_rate)
+{
+	struct ccu_mux *cm = hw_to_ccu_mux(hw);
+
+	return ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
+					   parent_rate);
+}
+
+const struct clk_ops ccu_mux_ops = {
+	.disable	= ccu_mux_disable,
+	.enable		= ccu_mux_enable,
+	.is_enabled	= ccu_mux_is_enabled,
+
+	.get_parent	= ccu_mux_get_parent,
+	.set_parent	= ccu_mux_set_parent,
+
+	.determine_rate	= __clk_mux_determine_rate,
+	.recalc_rate	= ccu_mux_recalc_rate,
+};
+
+/*
+ * This clock notifier is called when the frequency of the of the parent
+ * PLL clock is to be changed. The idea is to switch the parent to a
+ * stable clock, such as the main oscillator, while the PLL frequency
+ * stabilizes.
+ */
+static int ccu_mux_notifier_cb(struct notifier_block *nb,
+			       unsigned long event, void *data)
+{
+	struct ccu_mux_nb *mux = to_ccu_mux_nb(nb);
+	int ret = 0;
+
+	if (event == PRE_RATE_CHANGE) {
+		mux->original_index = ccu_mux_helper_get_parent(mux->common,
+								mux->cm);
+		ret = ccu_mux_helper_set_parent(mux->common, mux->cm,
+						mux->bypass_index);
+	} else if (event == POST_RATE_CHANGE) {
+		ret = ccu_mux_helper_set_parent(mux->common, mux->cm,
+						mux->original_index);
+	}
+
+	udelay(mux->delay_us);
+
+	return notifier_from_errno(ret);
+}
+
+int ccu_mux_notifier_register(struct clk *clk, struct ccu_mux_nb *mux_nb)
+{
+	mux_nb->clk_nb.notifier_call = ccu_mux_notifier_cb;
+
+	return clk_notifier_register(clk, &mux_nb->clk_nb);
+}