u-boot/drivers/timer/ast_timer.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2016 Google Inc.
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <timer.h>
#include <asm/io.h>
#include <asm/arch/timer.h>
#include <linux/err.h>
#define AST_TICK_TIMER 1
#define AST_TMC_RELOAD_VAL 0xffffffff
struct ast_timer_priv {
struct ast_timer *regs;
struct ast_timer_counter *tmc;
};
static struct ast_timer_counter *ast_get_timer_counter(struct ast_timer *timer,
int n)
{
if (n > 3)
return &timer->timers2[n - 4];
else
return &timer->timers1[n - 1];
}
static int ast_timer_probe(struct udevice *dev)
{
struct ast_timer_priv *priv = dev_get_priv(dev);
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
writel(AST_TMC_RELOAD_VAL, &priv->tmc->reload_val);
/*
* Stop the timer. This will also load reload_val into
* the status register.
*/
clrbits_le32(&priv->regs->ctrl1,
AST_TMC_EN << AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
/* Start the timer from the fixed 1MHz clock. */
setbits_le32(&priv->regs->ctrl1,
(AST_TMC_EN | AST_TMC_1MHZ) <<
AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
uc_priv->clock_rate = AST_TMC_RATE;
return 0;
}
static u64 ast_timer_get_count(struct udevice *dev)
{
struct ast_timer_priv *priv = dev_get_priv(dev);
return AST_TMC_RELOAD_VAL - readl(&priv->tmc->status);
}
static int ast_timer_ofdata_to_platdata(struct udevice *dev)
{
struct ast_timer_priv *priv = dev_get_priv(dev);
priv->regs = dev_read_addr_ptr(dev);
if (!priv->regs)
return -EINVAL;
priv->tmc = ast_get_timer_counter(priv->regs, AST_TICK_TIMER);
return 0;
}
static const struct timer_ops ast_timer_ops = {
.get_count = ast_timer_get_count,
};
static const struct udevice_id ast_timer_ids[] = {
{ .compatible = "aspeed,ast2500-timer" },
{ .compatible = "aspeed,ast2400-timer" },
{ }
};
U_BOOT_DRIVER(ast_timer) = {
.name = "ast_timer",
.id = UCLASS_TIMER,
.of_match = ast_timer_ids,
.probe = ast_timer_probe,
.priv_auto_alloc_size = sizeof(struct ast_timer_priv),
.ofdata_to_platdata = ast_timer_ofdata_to_platdata,
.ops = &ast_timer_ops,
};