drivers/clk/rockchip/clk-inverter.c

root/drivers/clk/rockchip/clk-inverter.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2015 Heiko Stuebner <heiko@sntech.de>
 */

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

struct rockchip_inv_clock {
        struct clk_hw   hw;
        void __iomem    *reg;
        int             shift;
        int             flags;
        spinlock_t      *lock;
};

#define to_inv_clock(_hw) container_of(_hw, struct rockchip_inv_clock, hw)

#define INVERTER_MASK 0x1

static int rockchip_inv_get_phase(struct clk_hw *hw)
{
        struct rockchip_inv_clock *inv_clock = to_inv_clock(hw);
        u32 val;

        val = readl(inv_clock->reg) >> inv_clock->shift;
        val &= INVERTER_MASK;
        return val ? 180 : 0;
}

static int rockchip_inv_set_phase(struct clk_hw *hw, int degrees)
{
        struct rockchip_inv_clock *inv_clock = to_inv_clock(hw);
        u32 val;

        if (degrees % 180 == 0) {
                val = !!degrees;
        } else {
                pr_err("%s: unsupported phase %d for %s\n",
                       __func__, degrees, clk_hw_get_name(hw));
                return -EINVAL;
        }

        if (inv_clock->flags & ROCKCHIP_INVERTER_HIWORD_MASK) {
                writel(HIWORD_UPDATE(val, INVERTER_MASK, inv_clock->shift),
                       inv_clock->reg);
        } else {
                unsigned long flags;
                u32 reg;

                spin_lock_irqsave(inv_clock->lock, flags);

                reg = readl(inv_clock->reg);
                reg &= ~BIT(inv_clock->shift);
                reg |= val;
                writel(reg, inv_clock->reg);

                spin_unlock_irqrestore(inv_clock->lock, flags);
        }

        return 0;
}

static const struct clk_ops rockchip_inv_clk_ops = {
        .get_phase      = rockchip_inv_get_phase,
        .set_phase      = rockchip_inv_set_phase,
};

struct clk *rockchip_clk_register_inverter(const char *name,
                                const char *const *parent_names, u8 num_parents,
                                void __iomem *reg, int shift, int flags,
                                spinlock_t *lock)
{
        struct clk_init_data init;
        struct rockchip_inv_clock *inv_clock;
        struct clk *clk;

        inv_clock = kmalloc_obj(*inv_clock);
        if (!inv_clock)
                return ERR_PTR(-ENOMEM);

        init.name = name;
        init.num_parents = num_parents;
        init.flags = CLK_SET_RATE_PARENT;
        init.parent_names = parent_names;
        init.ops = &rockchip_inv_clk_ops;

        inv_clock->hw.init = &init;
        inv_clock->reg = reg;
        inv_clock->shift = shift;
        inv_clock->flags = flags;
        inv_clock->lock = lock;

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

        return clk;
}
Linux
