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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2022 Svyatoslav Ryhel <clamor95@gmail.com>
*/
#include <dm.h>
#include <errno.h>
#include <timer.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/tegra.h>
#define TEGRA_OSC_CLK_ENB_L_SET (NV_PA_CLK_RST_BASE + 0x320)
#define TEGRA_OSC_SET_CLK_ENB_TMR BIT(5)
#define TEGRA_TIMER_USEC_CNTR (NV_PA_TMRUS_BASE + 0)
#define TEGRA_TIMER_USEC_CFG (NV_PA_TMRUS_BASE + 4)
#define TEGRA_TIMER_RATE 1000000 /* 1 MHz */
/*
* On pre-DM stage timer should be left configured by
* previous bootloader for correct 1MHz clock.
* In the case of reset default value is set to 1/13 of
* CLK_M which should be decent enough to safely
* get to DM stage.
*/
u64 notrace timer_early_get_count(void)
{
/* At this stage raw timer is used */
return readl(TEGRA_TIMER_USEC_CNTR);
}
unsigned long notrace timer_early_get_rate(void)
{
return TEGRA_TIMER_RATE;
}
ulong timer_get_boot_us(void)
{
return timer_early_get_count();
}
/*
* At moment of calling get_count, timer driver is already
* probed and is configured to have precise 1MHz clock.
* Tegra timer has a step of 1 microsecond which removes
* need of using adjusments involving uc_priv->clock_rate.
*/
static notrace u64 tegra_timer_get_count(struct udevice *dev)
{
u32 val = timer_early_get_count();
return timer_conv_64(val);
}
static int tegra_timer_probe(struct udevice *dev)
{
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
u32 usec_config, value;
/* Timer rate has to be set unconditionally */
uc_priv->clock_rate = TEGRA_TIMER_RATE;
/*
* Configure microsecond timers to have 1MHz clock
* Config register is 0xqqww, where qq is "dividend", ww is "divisor"
* Uses n+1 scheme
*/
switch (clock_get_rate(CLOCK_ID_CLK_M)) {
case 12000000:
usec_config = 0x000b; /* (11+1)/(0+1) */
break;
case 12800000:
usec_config = 0x043f; /* (63+1)/(4+1) */
break;
case 13000000:
usec_config = 0x000c; /* (12+1)/(0+1) */
break;
case 16800000:
usec_config = 0x0453; /* (83+1)/(4+1) */
break;
case 19200000:
usec_config = 0x045f; /* (95+1)/(4+1) */
break;
case 26000000:
usec_config = 0x0019; /* (25+1)/(0+1) */
break;
case 38400000:
usec_config = 0x04bf; /* (191+1)/(4+1) */
break;
case 48000000:
usec_config = 0x002f; /* (47+1)/(0+1) */
break;
default:
return -EINVAL;
}
/* Enable clock to timer hardware */
value = readl_relaxed(TEGRA_OSC_CLK_ENB_L_SET);
writel_relaxed(value | TEGRA_OSC_SET_CLK_ENB_TMR,
TEGRA_OSC_CLK_ENB_L_SET);
writel_relaxed(usec_config, TEGRA_TIMER_USEC_CFG);
return 0;
}
static const struct timer_ops tegra_timer_ops = {
.get_count = tegra_timer_get_count,
};
static const struct udevice_id tegra_timer_ids[] = {
{ .compatible = "nvidia,tegra20-timer" },
{ .compatible = "nvidia,tegra30-timer" },
{ .compatible = "nvidia,tegra114-timer" },
{ .compatible = "nvidia,tegra124-timer" },
{ .compatible = "nvidia,tegra210-timer" },
{ }
};
U_BOOT_DRIVER(tegra_timer) = {
.name = "tegra_timer",
.id = UCLASS_TIMER,
.of_match = tegra_timer_ids,
.probe = tegra_timer_probe,
.ops = &tegra_timer_ops,
.flags = DM_FLAG_PRE_RELOC,
};
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