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/*
* Copyright (C) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnio@jcrosoft.com>
*
* Under GPL v2
*/
#include <common.h>
#include <init.h>
#include <clock.h>
#include <io.h>
#include <driver.h>
#include <errno.h>
#include <linux/amba/sp804.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <asm/hardware/arm_timer.h>
static __iomem void *sp804_base;
static struct clk *sp804_clk;
static uint64_t sp804_read(void)
{
return ~readl(sp804_base + TIMER_VALUE);
}
static struct clocksource sp804_clksrc = {
.read = sp804_read,
.shift = 20,
.mask = CLOCKSOURCE_MASK(32),
};
static int sp804_probe(struct amba_device *dev, const struct amba_id *id)
{
u32 tick_rate;
int ret;
if (sp804_base) {
dev_err(&dev->dev, "single instance driver\n");
return -EBUSY;
}
sp804_clk = clk_get(&dev->dev, NULL);
if (IS_ERR(sp804_clk)) {
ret = PTR_ERR(sp804_clk);
dev_err(&dev->dev, "clock not found: %d\n", ret);
return ret;
}
ret = clk_enable(sp804_clk);
if (ret < 0) {
dev_err(&dev->dev, "clock failed to enable: %d\n", ret);
clk_put(sp804_clk);
return ret;
}
sp804_base = amba_get_mem_region(dev);
tick_rate = clk_get_rate(sp804_clk);
/* setup timer 0 as free-running clocksource */
writel(0, sp804_base + TIMER_CTRL);
writel(0xffffffff, sp804_base + TIMER_LOAD);
writel(0xffffffff, sp804_base + TIMER_VALUE);
writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
sp804_base + TIMER_CTRL);
sp804_clksrc.mult = clocksource_hz2mult(tick_rate, sp804_clksrc.shift);
return init_clock(&sp804_clksrc);
}
static struct amba_id sp804_ids[] = {
{
.id = AMBA_ARM_SP804_ID,
.mask = AMBA_ARM_SP804_ID_MASK,
},
{ 0, 0 },
};
struct amba_driver sp804_driver = {
.drv = {
.name = "sp804",
},
.probe = sp804_probe,
.id_table = sp804_ids,
};
static int sp804_init(void)
{
return amba_driver_register(&sp804_driver);
}
coredevice_initcall(sp804_init);
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