drivers/clk/imx/clk-gate-exclusive.c

root/drivers/clk/imx/clk-gate-exclusive.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2014 Freescale Semiconductor, Inc.
 */

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

/**
 * struct clk_gate_exclusive - i.MX specific gate clock which is mutually
 * exclusive with other gate clocks
 *
 * @gate: the parent class
 * @exclusive_mask: mask of gate bits which are mutually exclusive to this
 *      gate clock
 *
 * The imx exclusive gate clock is a subclass of basic clk_gate
 * with an additional mask to indicate which other gate bits in the same
 * register is mutually exclusive to this gate clock.
 */
struct clk_gate_exclusive {
        struct clk_gate gate;
        u32 exclusive_mask;
};

static int clk_gate_exclusive_enable(struct clk_hw *hw)
{
        struct clk_gate *gate = to_clk_gate(hw);
        struct clk_gate_exclusive *exgate = container_of(gate,
                                        struct clk_gate_exclusive, gate);
        u32 val = readl(gate->reg);

        if (val & exgate->exclusive_mask)
                return -EBUSY;

        return clk_gate_ops.enable(hw);
}

static void clk_gate_exclusive_disable(struct clk_hw *hw)
{
        clk_gate_ops.disable(hw);
}

static int clk_gate_exclusive_is_enabled(struct clk_hw *hw)
{
        return clk_gate_ops.is_enabled(hw);
}

static const struct clk_ops clk_gate_exclusive_ops = {
        .enable = clk_gate_exclusive_enable,
        .disable = clk_gate_exclusive_disable,
        .is_enabled = clk_gate_exclusive_is_enabled,
};

struct clk_hw *imx_clk_hw_gate_exclusive(const char *name, const char *parent,
         void __iomem *reg, u8 shift, u32 exclusive_mask)
{
        struct clk_gate_exclusive *exgate;
        struct clk_gate *gate;
        struct clk_hw *hw;
        struct clk_init_data init;
        int ret;

        if (exclusive_mask == 0)
                return ERR_PTR(-EINVAL);

        exgate = kzalloc_obj(*exgate);
        if (!exgate)
                return ERR_PTR(-ENOMEM);
        gate = &exgate->gate;

        init.name = name;
        init.ops = &clk_gate_exclusive_ops;
        init.flags = CLK_SET_RATE_PARENT;
        init.parent_names = parent ? &parent : NULL;
        init.num_parents = parent ? 1 : 0;

        gate->reg = reg;
        gate->bit_idx = shift;
        gate->lock = &imx_ccm_lock;
        gate->hw.init = &init;
        exgate->exclusive_mask = exclusive_mask;

        hw = &gate->hw;

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

        return hw;
}
Linux
