summaryrefslogtreecommitdiffstats
path: root/drivers/clk/mediatek/clk-mux.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/clk/mediatek/clk-mux.c')
-rw-r--r--drivers/clk/mediatek/clk-mux.c310
1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c
new file mode 100644
index 000000000..ba1720b9e
--- /dev/null
+++ b/drivers/clk/mediatek/clk-mux.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 MediaTek Inc.
+ * Author: Owen Chen <owen.chen@mediatek.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/compiler_types.h>
+#include <linux/container_of.h>
+#include <linux/err.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+
+#include "clk-mux.h"
+
+struct mtk_clk_mux {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ const struct mtk_mux *data;
+ spinlock_t *lock;
+ bool reparent;
+};
+
+static inline struct mtk_clk_mux *to_mtk_clk_mux(struct clk_hw *hw)
+{
+ return container_of(hw, struct mtk_clk_mux, hw);
+}
+
+static int mtk_clk_mux_enable_setclr(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+ else
+ __acquire(mux->lock);
+
+ regmap_write(mux->regmap, mux->data->clr_ofs,
+ BIT(mux->data->gate_shift));
+
+ /*
+ * If the parent has been changed when the clock was disabled, it will
+ * not be effective yet. Set the update bit to ensure the mux gets
+ * updated.
+ */
+ if (mux->reparent && mux->data->upd_shift >= 0) {
+ regmap_write(mux->regmap, mux->data->upd_ofs,
+ BIT(mux->data->upd_shift));
+ mux->reparent = false;
+ }
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+ else
+ __release(mux->lock);
+
+ return 0;
+}
+
+static void mtk_clk_mux_disable_setclr(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+
+ regmap_write(mux->regmap, mux->data->set_ofs,
+ BIT(mux->data->gate_shift));
+}
+
+static int mtk_clk_mux_is_enabled(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 val;
+
+ regmap_read(mux->regmap, mux->data->mux_ofs, &val);
+
+ return (val & BIT(mux->data->gate_shift)) == 0;
+}
+
+static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 mask = GENMASK(mux->data->mux_width - 1, 0);
+ u32 val;
+
+ regmap_read(mux->regmap, mux->data->mux_ofs, &val);
+ val = (val >> mux->data->mux_shift) & mask;
+
+ return val;
+}
+
+static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 mask = GENMASK(mux->data->mux_width - 1, 0);
+ u32 val, orig;
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+ else
+ __acquire(mux->lock);
+
+ regmap_read(mux->regmap, mux->data->mux_ofs, &orig);
+ val = (orig & ~(mask << mux->data->mux_shift))
+ | (index << mux->data->mux_shift);
+
+ if (val != orig) {
+ regmap_write(mux->regmap, mux->data->clr_ofs,
+ mask << mux->data->mux_shift);
+ regmap_write(mux->regmap, mux->data->set_ofs,
+ index << mux->data->mux_shift);
+
+ if (mux->data->upd_shift >= 0) {
+ regmap_write(mux->regmap, mux->data->upd_ofs,
+ BIT(mux->data->upd_shift));
+ mux->reparent = true;
+ }
+ }
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+ else
+ __release(mux->lock);
+
+ return 0;
+}
+
+static int mtk_clk_mux_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+
+ return clk_mux_determine_rate_flags(hw, req, mux->data->flags);
+}
+
+const struct clk_ops mtk_mux_clr_set_upd_ops = {
+ .get_parent = mtk_clk_mux_get_parent,
+ .set_parent = mtk_clk_mux_set_parent_setclr_lock,
+ .determine_rate = mtk_clk_mux_determine_rate,
+};
+EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops);
+
+const struct clk_ops mtk_mux_gate_clr_set_upd_ops = {
+ .enable = mtk_clk_mux_enable_setclr,
+ .disable = mtk_clk_mux_disable_setclr,
+ .is_enabled = mtk_clk_mux_is_enabled,
+ .get_parent = mtk_clk_mux_get_parent,
+ .set_parent = mtk_clk_mux_set_parent_setclr_lock,
+ .determine_rate = mtk_clk_mux_determine_rate,
+};
+EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);
+
+static struct clk_hw *mtk_clk_register_mux(const struct mtk_mux *mux,
+ struct regmap *regmap,
+ spinlock_t *lock)
+{
+ struct mtk_clk_mux *clk_mux;
+ struct clk_init_data init = {};
+ int ret;
+
+ clk_mux = kzalloc(sizeof(*clk_mux), GFP_KERNEL);
+ if (!clk_mux)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = mux->name;
+ init.flags = mux->flags | CLK_SET_RATE_PARENT;
+ init.parent_names = mux->parent_names;
+ init.num_parents = mux->num_parents;
+ init.ops = mux->ops;
+
+ clk_mux->regmap = regmap;
+ clk_mux->data = mux;
+ clk_mux->lock = lock;
+ clk_mux->hw.init = &init;
+
+ ret = clk_hw_register(NULL, &clk_mux->hw);
+ if (ret) {
+ kfree(clk_mux);
+ return ERR_PTR(ret);
+ }
+
+ return &clk_mux->hw;
+}
+
+static void mtk_clk_unregister_mux(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux;
+ if (!hw)
+ return;
+
+ mux = to_mtk_clk_mux(hw);
+
+ clk_hw_unregister(hw);
+ kfree(mux);
+}
+
+int mtk_clk_register_muxes(const struct mtk_mux *muxes,
+ int num, struct device_node *node,
+ spinlock_t *lock,
+ struct clk_hw_onecell_data *clk_data)
+{
+ struct regmap *regmap;
+ struct clk_hw *hw;
+ int i;
+
+ regmap = device_node_to_regmap(node);
+ if (IS_ERR(regmap)) {
+ pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
+ return PTR_ERR(regmap);
+ }
+
+ for (i = 0; i < num; i++) {
+ const struct mtk_mux *mux = &muxes[i];
+
+ if (!IS_ERR_OR_NULL(clk_data->hws[mux->id])) {
+ pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
+ node, mux->id);
+ continue;
+ }
+
+ hw = mtk_clk_register_mux(mux, regmap, lock);
+
+ if (IS_ERR(hw)) {
+ pr_err("Failed to register clk %s: %pe\n", mux->name,
+ hw);
+ goto err;
+ }
+
+ clk_data->hws[mux->id] = hw;
+ }
+
+ return 0;
+
+err:
+ while (--i >= 0) {
+ const struct mtk_mux *mux = &muxes[i];
+
+ if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
+ continue;
+
+ mtk_clk_unregister_mux(clk_data->hws[mux->id]);
+ clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
+ }
+
+ return PTR_ERR(hw);
+}
+EXPORT_SYMBOL_GPL(mtk_clk_register_muxes);
+
+void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
+ struct clk_hw_onecell_data *clk_data)
+{
+ int i;
+
+ if (!clk_data)
+ return;
+
+ for (i = num; i > 0; i--) {
+ const struct mtk_mux *mux = &muxes[i - 1];
+
+ if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
+ continue;
+
+ mtk_clk_unregister_mux(clk_data->hws[mux->id]);
+ clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
+ }
+}
+EXPORT_SYMBOL_GPL(mtk_clk_unregister_muxes);
+
+/*
+ * This clock notifier is called when the frequency 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 mtk_clk_mux_notifier_cb(struct notifier_block *nb,
+ unsigned long event, void *_data)
+{
+ struct clk_notifier_data *data = _data;
+ struct clk_hw *hw = __clk_get_hw(data->clk);
+ struct mtk_mux_nb *mux_nb = to_mtk_mux_nb(nb);
+ int ret = 0;
+
+ switch (event) {
+ case PRE_RATE_CHANGE:
+ mux_nb->original_index = mux_nb->ops->get_parent(hw);
+ ret = mux_nb->ops->set_parent(hw, mux_nb->bypass_index);
+ break;
+ case POST_RATE_CHANGE:
+ case ABORT_RATE_CHANGE:
+ ret = mux_nb->ops->set_parent(hw, mux_nb->original_index);
+ break;
+ }
+
+ return notifier_from_errno(ret);
+}
+
+int devm_mtk_clk_mux_notifier_register(struct device *dev, struct clk *clk,
+ struct mtk_mux_nb *mux_nb)
+{
+ mux_nb->nb.notifier_call = mtk_clk_mux_notifier_cb;
+
+ return devm_clk_notifier_register(dev, clk, &mux_nb->nb);
+}
+EXPORT_SYMBOL_GPL(devm_mtk_clk_mux_notifier_register);
+
+MODULE_LICENSE("GPL");