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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/clk/sunxi-ng/ccu_mux.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/clk/sunxi-ng/ccu_mux.c')
-rw-r--r--drivers/clk/sunxi-ng/ccu_mux.c300
1 files changed, 300 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..1d557e323
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu_mux.c
@@ -0,0 +1,300 @@
+// 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"
+
+#define CCU_MUX_KEY_VALUE 0x16aa0000
+
+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);
+}
+EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_apply_prediv, SUNXI_CCU);
+
+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;
+}
+EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_determine_rate, SUNXI_CCU);
+
+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;
+}
+EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_get_parent, SUNXI_CCU);
+
+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);
+
+ /* The key field always reads as zero. */
+ if (common->features & CCU_FEATURE_KEY_FIELD)
+ reg |= CCU_MUX_KEY_VALUE;
+
+ 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;
+}
+EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_set_parent, SUNXI_CCU);
+
+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,
+};
+EXPORT_SYMBOL_NS_GPL(ccu_mux_ops, SUNXI_CCU);
+
+/*
+ * 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);
+}
+EXPORT_SYMBOL_NS_GPL(ccu_mux_notifier_register, SUNXI_CCU);