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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author(s): Patrice Chotard, <patrice.chotard@foss.st.com> for STMicroelectronics.
*
* ARM Cortext A9 global timer driver
*/
#include <common.h>
#include <dm.h>
#include <clk.h>
#include <timer.h>
#include <linux/err.h>
#include <asm/io.h>
#include <asm/arch-armv7/globaltimer.h>
struct arm_global_timer_priv {
struct globaltimer *global_timer;
};
static u64 arm_global_timer_get_count(struct udevice *dev)
{
struct arm_global_timer_priv *priv = dev_get_priv(dev);
struct globaltimer *global_timer = priv->global_timer;
u32 low, high;
u64 timer;
u32 old = readl(&global_timer->cnt_h);
while (1) {
low = readl(&global_timer->cnt_l);
high = readl(&global_timer->cnt_h);
if (old == high)
break;
else
old = high;
}
timer = high;
return (u64)((timer << 32) | low);
}
static int arm_global_timer_probe(struct udevice *dev)
{
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct arm_global_timer_priv *priv = dev_get_priv(dev);
struct clk clk;
int err;
ulong ret;
/* get arm global timer base address */
priv->global_timer = (struct globaltimer *)dev_read_addr_ptr(dev);
if (!priv->global_timer)
return -ENOENT;
err = clk_get_by_index(dev, 0, &clk);
if (!err) {
ret = clk_get_rate(&clk);
if (IS_ERR_VALUE(ret))
return ret;
uc_priv->clock_rate = ret;
} else {
uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
}
/* init timer */
writel(0x01, &priv->global_timer->ctl);
return 0;
}
static const struct timer_ops arm_global_timer_ops = {
.get_count = arm_global_timer_get_count,
};
static const struct udevice_id arm_global_timer_ids[] = {
{ .compatible = "arm,cortex-a9-global-timer" },
{}
};
U_BOOT_DRIVER(arm_global_timer) = {
.name = "arm_global_timer",
.id = UCLASS_TIMER,
.of_match = arm_global_timer_ids,
.priv_auto = sizeof(struct arm_global_timer_priv),
.probe = arm_global_timer_probe,
.ops = &arm_global_timer_ops,
};
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