drivers/clk/imx/clk-fixup-mux.c

root/drivers/clk/imx/clk-fixup-mux.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2013 Freescale Semiconductor, Inc.
 */

#include <linux/bits.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "clk.h"

/**
 * struct clk_fixup_mux - imx integer fixup multiplexer clock
 * @mux: the parent class
 * @ops: pointer to clk_ops of parent class
 * @fixup: a hook to fixup the write value
 *
 * The imx fixup multiplexer clock is a subclass of basic clk_mux
 * with an additional fixup hook.
 */
struct clk_fixup_mux {
        struct clk_mux mux;
        const struct clk_ops *ops;
        void (*fixup)(u32 *val);
};

static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
{
        struct clk_mux *mux = to_clk_mux(hw);

        return container_of(mux, struct clk_fixup_mux, mux);
}

static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
{
        struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);

        return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
}

static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
{
        struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
        struct clk_mux *mux = to_clk_mux(hw);
        unsigned long flags;
        u32 val;

        spin_lock_irqsave(mux->lock, flags);

        val = readl(mux->reg);
        val &= ~(mux->mask << mux->shift);
        val |= index << mux->shift;
        fixup_mux->fixup(&val);
        writel(val, mux->reg);

        spin_unlock_irqrestore(mux->lock, flags);

        return 0;
}

static const struct clk_ops clk_fixup_mux_ops = {
        .determine_rate = clk_hw_determine_rate_no_reparent,
        .get_parent = clk_fixup_mux_get_parent,
        .set_parent = clk_fixup_mux_set_parent,
};

struct clk_hw *imx_clk_hw_fixup_mux(const char *name, void __iomem *reg,
                              u8 shift, u8 width, const char * const *parents,
                              int num_parents, void (*fixup)(u32 *val))
{
        struct clk_fixup_mux *fixup_mux;
        struct clk_hw *hw;
        struct clk_init_data init;
        int ret;

        if (!fixup)
                return ERR_PTR(-EINVAL);

        fixup_mux = kzalloc_obj(*fixup_mux);
        if (!fixup_mux)
                return ERR_PTR(-ENOMEM);

        init.name = name;
        init.ops = &clk_fixup_mux_ops;
        init.parent_names = parents;
        init.num_parents = num_parents;
        init.flags = 0;

        fixup_mux->mux.reg = reg;
        fixup_mux->mux.shift = shift;
        fixup_mux->mux.mask = BIT(width) - 1;
        fixup_mux->mux.lock = &imx_ccm_lock;
        fixup_mux->mux.hw.init = &init;
        fixup_mux->ops = &clk_mux_ops;
        fixup_mux->fixup = fixup;

        hw = &fixup_mux->mux.hw;

        ret = clk_hw_register(NULL, hw);
        if (ret) {
                kfree(fixup_mux);
                return ERR_PTR(ret);
        }

        return hw;
}
Linux
