u-boot/drivers/timer/dw-apb-timer.c
Marek Vasut e09c1a1331 timer: dw-apb: Add missing 64bit up-conversion
The generic timer count is an incrementing 64bit value and a timer driver
must return an incrementing 64bit value. The DW APB timer only provides a
32bit timer counting down, thus the result must be inverted and converted
to a 64bit value. The current implementation is however missing the 64bit
up-conversion and this results in random timer roll-overs, which in turn
triggers random timeouts throughout the codebase.

This patch adds the missing 64bit up-conversion to fix the issue.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <chin.liang.see@intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Cc: Tien Fong Chee <tien.fong.chee@intel.com>
2019-04-17 22:20:18 +02:00

89 lines
1.8 KiB
C

// 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 = timer_conv_64(~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,
.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),
};