286 lines
6.4 KiB
C
286 lines
6.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
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* Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
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* Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
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*
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* Simple multiplexer clock implementation
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*/
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#include <linux/clk-provider.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/err.h>
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/*
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* DOC: basic adjustable multiplexer clock that cannot gate
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*
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* Traits of this clock:
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* prepare - clk_prepare only ensures that parents are prepared
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* enable - clk_enable only ensures that parents are enabled
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* rate - rate is only affected by parent switching. No clk_set_rate support
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* parent - parent is adjustable through clk_set_parent
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*/
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static inline u32 clk_mux_readl(struct clk_mux *mux)
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{
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if (mux->flags & CLK_MUX_BIG_ENDIAN)
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return ioread32be(mux->reg);
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return readl(mux->reg);
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}
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static inline void clk_mux_writel(struct clk_mux *mux, u32 val)
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{
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if (mux->flags & CLK_MUX_BIG_ENDIAN)
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iowrite32be(val, mux->reg);
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else
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writel(val, mux->reg);
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}
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int clk_mux_val_to_index(struct clk_hw *hw, u32 *table, unsigned int flags,
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unsigned int val)
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{
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int num_parents = clk_hw_get_num_parents(hw);
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if (table) {
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int i;
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for (i = 0; i < num_parents; i++)
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if (table[i] == val)
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return i;
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return -EINVAL;
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}
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if (val && (flags & CLK_MUX_INDEX_BIT))
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val = ffs(val) - 1;
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if (val && (flags & CLK_MUX_INDEX_ONE))
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val--;
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if (val >= num_parents)
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return -EINVAL;
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return val;
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}
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EXPORT_SYMBOL_GPL(clk_mux_val_to_index);
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unsigned int clk_mux_index_to_val(u32 *table, unsigned int flags, u8 index)
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{
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unsigned int val = index;
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if (table) {
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val = table[index];
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} else {
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if (flags & CLK_MUX_INDEX_BIT)
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val = 1 << index;
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if (flags & CLK_MUX_INDEX_ONE)
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val++;
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}
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return val;
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}
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EXPORT_SYMBOL_GPL(clk_mux_index_to_val);
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static u8 clk_mux_get_parent(struct clk_hw *hw)
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{
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struct clk_mux *mux = to_clk_mux(hw);
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u32 val;
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val = clk_mux_readl(mux) >> mux->shift;
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val &= mux->mask;
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return clk_mux_val_to_index(hw, mux->table, mux->flags, val);
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}
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static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
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{
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struct clk_mux *mux = to_clk_mux(hw);
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u32 val = clk_mux_index_to_val(mux->table, mux->flags, index);
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unsigned long flags = 0;
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u32 reg;
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if (mux->lock)
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spin_lock_irqsave(mux->lock, flags);
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else
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__acquire(mux->lock);
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if (mux->flags & CLK_MUX_HIWORD_MASK) {
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reg = mux->mask << (mux->shift + 16);
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} else {
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reg = clk_mux_readl(mux);
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reg &= ~(mux->mask << mux->shift);
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}
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val = val << mux->shift;
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reg |= val;
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clk_mux_writel(mux, reg);
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if (mux->lock)
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spin_unlock_irqrestore(mux->lock, flags);
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else
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__release(mux->lock);
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return 0;
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}
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static int clk_mux_determine_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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struct clk_mux *mux = to_clk_mux(hw);
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return clk_mux_determine_rate_flags(hw, req, mux->flags);
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}
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const struct clk_ops clk_mux_ops = {
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.get_parent = clk_mux_get_parent,
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.set_parent = clk_mux_set_parent,
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.determine_rate = clk_mux_determine_rate,
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};
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EXPORT_SYMBOL_GPL(clk_mux_ops);
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const struct clk_ops clk_mux_ro_ops = {
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.get_parent = clk_mux_get_parent,
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};
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EXPORT_SYMBOL_GPL(clk_mux_ro_ops);
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struct clk_hw *__clk_hw_register_mux(struct device *dev, struct device_node *np,
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const char *name, u8 num_parents,
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const char * const *parent_names,
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const struct clk_hw **parent_hws,
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const struct clk_parent_data *parent_data,
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unsigned long flags, void __iomem *reg, u8 shift, u32 mask,
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u8 clk_mux_flags, u32 *table, spinlock_t *lock)
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{
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struct clk_mux *mux;
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struct clk_hw *hw;
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struct clk_init_data init = {};
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u8 width = 0;
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int ret = -EINVAL;
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if (clk_mux_flags & CLK_MUX_HIWORD_MASK) {
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width = fls(mask) - ffs(mask) + 1;
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if (width + shift > 16) {
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pr_err("mux value exceeds LOWORD field\n");
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return ERR_PTR(-EINVAL);
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}
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}
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/* allocate the mux */
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mux = kzalloc(sizeof(*mux), GFP_KERNEL);
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if (!mux)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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if (clk_mux_flags & CLK_MUX_READ_ONLY)
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init.ops = &clk_mux_ro_ops;
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else
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init.ops = &clk_mux_ops;
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init.flags = flags;
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init.parent_names = parent_names;
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init.parent_data = parent_data;
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init.parent_hws = parent_hws;
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init.num_parents = num_parents;
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/* struct clk_mux assignments */
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mux->reg = reg;
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mux->shift = shift;
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mux->mask = mask;
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mux->flags = clk_mux_flags;
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mux->lock = lock;
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mux->table = table;
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mux->hw.init = &init;
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hw = &mux->hw;
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if (dev || !np)
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ret = clk_hw_register(dev, hw);
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else if (np)
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ret = of_clk_hw_register(np, hw);
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if (ret) {
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kfree(mux);
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hw = ERR_PTR(ret);
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}
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return hw;
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}
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EXPORT_SYMBOL_GPL(__clk_hw_register_mux);
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static void devm_clk_hw_release_mux(struct device *dev, void *res)
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{
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clk_hw_unregister_mux(*(struct clk_hw **)res);
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}
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struct clk_hw *__devm_clk_hw_register_mux(struct device *dev, struct device_node *np,
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const char *name, u8 num_parents,
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const char * const *parent_names,
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const struct clk_hw **parent_hws,
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const struct clk_parent_data *parent_data,
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unsigned long flags, void __iomem *reg, u8 shift, u32 mask,
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u8 clk_mux_flags, u32 *table, spinlock_t *lock)
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{
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struct clk_hw **ptr, *hw;
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ptr = devres_alloc(devm_clk_hw_release_mux, sizeof(*ptr), GFP_KERNEL);
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if (!ptr)
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return ERR_PTR(-ENOMEM);
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hw = __clk_hw_register_mux(dev, np, name, num_parents, parent_names, parent_hws,
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parent_data, flags, reg, shift, mask,
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clk_mux_flags, table, lock);
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if (!IS_ERR(hw)) {
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*ptr = hw;
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devres_add(dev, ptr);
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} else {
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devres_free(ptr);
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}
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return hw;
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}
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EXPORT_SYMBOL_GPL(__devm_clk_hw_register_mux);
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struct clk *clk_register_mux_table(struct device *dev, const char *name,
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const char * const *parent_names, u8 num_parents,
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unsigned long flags, void __iomem *reg, u8 shift, u32 mask,
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u8 clk_mux_flags, u32 *table, spinlock_t *lock)
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{
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struct clk_hw *hw;
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hw = clk_hw_register_mux_table(dev, name, parent_names,
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num_parents, flags, reg, shift, mask,
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clk_mux_flags, table, lock);
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if (IS_ERR(hw))
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return ERR_CAST(hw);
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return hw->clk;
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}
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EXPORT_SYMBOL_GPL(clk_register_mux_table);
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void clk_unregister_mux(struct clk *clk)
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{
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struct clk_mux *mux;
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struct clk_hw *hw;
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hw = __clk_get_hw(clk);
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if (!hw)
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return;
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mux = to_clk_mux(hw);
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clk_unregister(clk);
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kfree(mux);
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}
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EXPORT_SYMBOL_GPL(clk_unregister_mux);
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void clk_hw_unregister_mux(struct clk_hw *hw)
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{
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struct clk_mux *mux;
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mux = to_clk_mux(hw);
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clk_hw_unregister(hw);
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kfree(mux);
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}
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EXPORT_SYMBOL_GPL(clk_hw_unregister_mux);
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