mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-28 15:41:40 +00:00
b789e4f215
Add Nuvoton BMC NPCM7xx/NPCM8xx timer driver. Signed-off-by: Jim Liu <JJLIU0@nuvoton.com> Signed-off-by: Stanley Chu <yschu@nuvoton.com>
115 lines
2.9 KiB
C
115 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright (c) 2022 Nuvoton Technology Corp.
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <clk.h>
|
|
#include <dm.h>
|
|
#include <timer.h>
|
|
#include <asm/io.h>
|
|
|
|
#define NPCM_TIMER_CLOCK_RATE 1000000UL /* 1MHz timer */
|
|
#define NPCM_TIMER_INPUT_RATE 25000000UL /* Rate of input clock */
|
|
#define NPCM_TIMER_TDR_MASK GENMASK(23, 0)
|
|
#define NPCM_TIMER_MAX_VAL NPCM_TIMER_TDR_MASK /* max counter value */
|
|
|
|
/* Register offsets */
|
|
#define TCR0 0x0 /* Timer Control and Status Register */
|
|
#define TICR0 0x8 /* Timer Initial Count Register */
|
|
#define TDR0 0x10 /* Timer Data Register */
|
|
|
|
/* TCR fields */
|
|
#define TCR_MODE_PERIODIC BIT(27)
|
|
#define TCR_EN BIT(30)
|
|
#define TCR_PRESCALE (NPCM_TIMER_INPUT_RATE / NPCM_TIMER_CLOCK_RATE - 1)
|
|
|
|
enum input_clock_type {
|
|
INPUT_CLOCK_FIXED, /* input clock rate is fixed */
|
|
INPUT_CLOCK_NON_FIXED
|
|
};
|
|
|
|
/**
|
|
* struct npcm_timer_priv - private data for npcm timer driver
|
|
* npcm timer is a 24-bits down-counting timer.
|
|
*
|
|
* @last_count: last hw counter value
|
|
* @counter: the value to be returned for get_count ops
|
|
*/
|
|
struct npcm_timer_priv {
|
|
void __iomem *base;
|
|
u32 last_count;
|
|
u64 counter;
|
|
};
|
|
|
|
static u64 npcm_timer_get_count(struct udevice *dev)
|
|
{
|
|
struct npcm_timer_priv *priv = dev_get_priv(dev);
|
|
u32 val;
|
|
|
|
/* The timer is counting down */
|
|
val = readl(priv->base + TDR0) & NPCM_TIMER_TDR_MASK;
|
|
if (val <= priv->last_count)
|
|
priv->counter += priv->last_count - val;
|
|
else
|
|
priv->counter += priv->last_count + (NPCM_TIMER_MAX_VAL + 1 - val);
|
|
priv->last_count = val;
|
|
|
|
return priv->counter;
|
|
}
|
|
|
|
static int npcm_timer_probe(struct udevice *dev)
|
|
{
|
|
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
|
|
struct npcm_timer_priv *priv = dev_get_priv(dev);
|
|
enum input_clock_type type = dev_get_driver_data(dev);
|
|
struct clk clk;
|
|
int ret;
|
|
|
|
priv->base = dev_read_addr_ptr(dev);
|
|
if (!priv->base)
|
|
return -EINVAL;
|
|
uc_priv->clock_rate = NPCM_TIMER_CLOCK_RATE;
|
|
|
|
if (type == INPUT_CLOCK_NON_FIXED) {
|
|
ret = clk_get_by_index(dev, 0, &clk);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = clk_set_rate(&clk, NPCM_TIMER_INPUT_RATE);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Configure timer and start
|
|
* periodic mode
|
|
* timer clock rate = input clock / prescale
|
|
*/
|
|
writel(0, priv->base + TCR0);
|
|
writel(NPCM_TIMER_MAX_VAL, priv->base + TICR0);
|
|
writel(TCR_EN | TCR_MODE_PERIODIC | TCR_PRESCALE,
|
|
priv->base + TCR0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct timer_ops npcm_timer_ops = {
|
|
.get_count = npcm_timer_get_count,
|
|
};
|
|
|
|
static const struct udevice_id npcm_timer_ids[] = {
|
|
{ .compatible = "nuvoton,npcm845-timer", .data = INPUT_CLOCK_FIXED},
|
|
{ .compatible = "nuvoton,npcm750-timer", .data = INPUT_CLOCK_NON_FIXED},
|
|
{}
|
|
};
|
|
|
|
U_BOOT_DRIVER(npcm_timer) = {
|
|
.name = "npcm_timer",
|
|
.id = UCLASS_TIMER,
|
|
.of_match = npcm_timer_ids,
|
|
.priv_auto = sizeof(struct npcm_timer_priv),
|
|
.probe = npcm_timer_probe,
|
|
.ops = &npcm_timer_ops,
|
|
.flags = DM_FLAG_PRE_RELOC,
|
|
};
|