drivers/clk/mediatek/clk-apmixed.c

root/drivers/clk/mediatek/clk-apmixed.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015 MediaTek Inc.
 * Author: James Liao <jamesjj.liao@mediatek.com>
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/slab.h>

#include "clk-mtk.h"

#define REF2USB_TX_EN           BIT(0)
#define REF2USB_TX_LPF_EN       BIT(1)
#define REF2USB_TX_OUT_EN       BIT(2)
#define REF2USB_EN_MASK         (REF2USB_TX_EN | REF2USB_TX_LPF_EN | \
                                 REF2USB_TX_OUT_EN)

struct mtk_ref2usb_tx {
        struct clk_hw   hw;
        void __iomem    *base_addr;
};

static inline struct mtk_ref2usb_tx *to_mtk_ref2usb_tx(struct clk_hw *hw)
{
        return container_of(hw, struct mtk_ref2usb_tx, hw);
}

static int mtk_ref2usb_tx_is_prepared(struct clk_hw *hw)
{
        struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);

        return (readl(tx->base_addr) & REF2USB_EN_MASK) == REF2USB_EN_MASK;
}

static int mtk_ref2usb_tx_prepare(struct clk_hw *hw)
{
        struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
        u32 val;

        val = readl(tx->base_addr);

        val |= REF2USB_TX_EN;
        writel(val, tx->base_addr);
        udelay(100);

        val |= REF2USB_TX_LPF_EN;
        writel(val, tx->base_addr);

        val |= REF2USB_TX_OUT_EN;
        writel(val, tx->base_addr);

        return 0;
}

static void mtk_ref2usb_tx_unprepare(struct clk_hw *hw)
{
        struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
        u32 val;

        val = readl(tx->base_addr);
        val &= ~REF2USB_EN_MASK;
        writel(val, tx->base_addr);
}

static const struct clk_ops mtk_ref2usb_tx_ops = {
        .is_prepared    = mtk_ref2usb_tx_is_prepared,
        .prepare        = mtk_ref2usb_tx_prepare,
        .unprepare      = mtk_ref2usb_tx_unprepare,
};

struct clk_hw *mtk_clk_register_ref2usb_tx(const char *name,
                        const char *parent_name, void __iomem *reg)
{
        struct mtk_ref2usb_tx *tx;
        struct clk_init_data init = {};
        int ret;

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

        tx->base_addr = reg;
        tx->hw.init = &init;

        init.name = name;
        init.ops = &mtk_ref2usb_tx_ops;
        init.parent_names = &parent_name;
        init.num_parents = 1;

        ret = clk_hw_register(NULL, &tx->hw);

        if (ret) {
                kfree(tx);
                return ERR_PTR(ret);
        }

        return &tx->hw;
}
EXPORT_SYMBOL_GPL(mtk_clk_register_ref2usb_tx);

void mtk_clk_unregister_ref2usb_tx(struct clk_hw *hw)
{
        struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);

        clk_hw_unregister(hw);
        kfree(tx);
}
EXPORT_SYMBOL_GPL(mtk_clk_unregister_ref2usb_tx);

MODULE_LICENSE("GPL");
Linux
