u-boot/drivers/timer/dw-apb-timer.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Designware APB Timer driver
*
* Copyright (C) 2018 Marek Vasut <marex@denx.de>
*/
#include <common.h>
#include <dm.h>
#include <clk.h>
#include <timer.h>
#include <asm/io.h>
#include <asm/arch/timer.h>
#define DW_APB_LOAD_VAL 0x0
#define DW_APB_CURR_VAL 0x4
#define DW_APB_CTRL 0x8
DECLARE_GLOBAL_DATA_PTR;
struct dw_apb_timer_priv {
fdt_addr_t regs;
};
static int dw_apb_timer_get_count(struct udevice *dev, u64 *count)
{
struct dw_apb_timer_priv *priv = dev_get_priv(dev);
/*
* The DW APB counter counts down, but this function
* requires the count to be incrementing. Invert the
* result.
*/
*count = ~readl(priv->regs + DW_APB_CURR_VAL);
return 0;
}
static int dw_apb_timer_probe(struct udevice *dev)
{
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct dw_apb_timer_priv *priv = dev_get_priv(dev);
struct clk clk;
int ret;
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return ret;
uc_priv->clock_rate = clk_get_rate(&clk);
clk_free(&clk);
/* init timer */
writel(0xffffffff, priv->regs + DW_APB_LOAD_VAL);
writel(0xffffffff, priv->regs + DW_APB_CURR_VAL);
setbits_le32(priv->regs + DW_APB_CTRL, 0x3);
return 0;
}
static int dw_apb_timer_ofdata_to_platdata(struct udevice *dev)
{
struct dw_apb_timer_priv *priv = dev_get_priv(dev);
priv->regs = dev_read_addr(dev);
return 0;
}
static const struct timer_ops dw_apb_timer_ops = {
.get_count = dw_apb_timer_get_count,
};
static const struct udevice_id dw_apb_timer_ids[] = {
{ .compatible = "snps,dw-apb-timer" },
{}
};
U_BOOT_DRIVER(dw_apb_timer) = {
.name = "dw_apb_timer",
.id = UCLASS_TIMER,
.ops = &dw_apb_timer_ops,
.probe = dw_apb_timer_probe,
.flags = DM_FLAG_PRE_RELOC,
.of_match = dw_apb_timer_ids,
.ofdata_to_platdata = dw_apb_timer_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct dw_apb_timer_priv),
};