linux-imx

/*

 * Generic MMIO clocksource support

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include <linux/clocksource.h>

#include <linux/errno.h>

#include <linux/init.h>

#include <linux/slab.h>

​

struct clocksource_mmio {

    void __iomem *reg;

    struct clocksource clksrc;

};

​

static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)

{

    return container_of(c, struct clocksource_mmio, clksrc);

}

​

u64 clocksource_mmio_readl_up(struct clocksource *c)

{

    return (u64)readl_relaxed(to_mmio_clksrc(c)->reg);

}

​

u64 clocksource_mmio_readl_down(struct clocksource *c)

{

    return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;

}

​

u64 clocksource_mmio_readw_up(struct clocksource *c)

{

    return (u64)readw_relaxed(to_mmio_clksrc(c)->reg);

}

​

u64 clocksource_mmio_readw_down(struct clocksource *c)

{

    return ~(u64)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;

}

​

/**

 * clocksource_mmio_init - Initialize a simple mmio based clocksource

 * @base:   Virtual address of the clock readout register

 * @name:   Name of the clocksource

 * @hz:     Frequency of the clocksource in Hz

 * @rating: Rating of the clocksource

 * @bits:   Number of valid bits

 * @read:   One of clocksource_mmio_read*() above

 */

int __init clocksource_mmio_init(void __iomem *base, const char *name,

    unsigned long hz, int rating, unsigned bits,

    u64 (*read)(struct clocksource *))

{

    struct clocksource_mmio *cs;

​

    if (bits > 64 || bits < 16)

        return -EINVAL;

​

    cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);

    if (!cs)

        return -ENOMEM;