drivers/clk/tegra/clk-pll-out.c

root/drivers/clk/tegra/clk-pll-out.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/clk-provider.h>

#include "clk.h"

#define pll_out_enb(p) (BIT(p->enb_bit_idx))
#define pll_out_rst(p) (BIT(p->rst_bit_idx))

static int clk_pll_out_is_enabled(struct clk_hw *hw)
{
        struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
        u32 val = readl_relaxed(pll_out->reg);
        int state;

        state = (val & pll_out_enb(pll_out)) ? 1 : 0;
        if (!(val & (pll_out_rst(pll_out))))
                state = 0;
        return state;
}

static int clk_pll_out_enable(struct clk_hw *hw)
{
        struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
        unsigned long flags = 0;
        u32 val;

        if (pll_out->lock)
                spin_lock_irqsave(pll_out->lock, flags);

        val = readl_relaxed(pll_out->reg);

        val |= (pll_out_enb(pll_out) | pll_out_rst(pll_out));

        writel_relaxed(val, pll_out->reg);
        udelay(2);

        if (pll_out->lock)
                spin_unlock_irqrestore(pll_out->lock, flags);

        return 0;
}

static void clk_pll_out_disable(struct clk_hw *hw)
{
        struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
        unsigned long flags = 0;
        u32 val;

        if (pll_out->lock)
                spin_lock_irqsave(pll_out->lock, flags);

        val = readl_relaxed(pll_out->reg);

        val &= ~(pll_out_enb(pll_out) | pll_out_rst(pll_out));

        writel_relaxed(val, pll_out->reg);
        udelay(2);

        if (pll_out->lock)
                spin_unlock_irqrestore(pll_out->lock, flags);
}

static void tegra_clk_pll_out_restore_context(struct clk_hw *hw)
{
        if (!__clk_get_enable_count(hw->clk))
                clk_pll_out_disable(hw);
        else
                clk_pll_out_enable(hw);
}

const struct clk_ops tegra_clk_pll_out_ops = {
        .is_enabled = clk_pll_out_is_enabled,
        .enable = clk_pll_out_enable,
        .disable = clk_pll_out_disable,
        .restore_context = tegra_clk_pll_out_restore_context,
};

struct clk *tegra_clk_register_pll_out(const char *name,
                const char *parent_name, void __iomem *reg, u8 enb_bit_idx,
                u8 rst_bit_idx, unsigned long flags, u8 pll_out_flags,
                spinlock_t *lock)
{
        struct tegra_clk_pll_out *pll_out;
        struct clk *clk;
        struct clk_init_data init;

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

        init.name = name;
        init.ops = &tegra_clk_pll_out_ops;
        init.parent_names = (parent_name ? &parent_name : NULL);
        init.num_parents = (parent_name ? 1 : 0);
        init.flags = flags;

        pll_out->reg = reg;
        pll_out->enb_bit_idx = enb_bit_idx;
        pll_out->rst_bit_idx = rst_bit_idx;
        pll_out->flags = pll_out_flags;
        pll_out->lock = lock;

        /* Data in .init is copied by clk_register(), so stack variable OK */
        pll_out->hw.init = &init;

        clk = clk_register(NULL, &pll_out->hw);
        if (IS_ERR(clk))
                kfree(pll_out);

        return clk;
}
Linux
