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// SPDX-License-Identifier: GPL-2.0+
/*
* 64-bit Periodic Interval Timer driver
*
* Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
*
* Author: Claudiu Beznea <claudiu.beznea@microchip.com>
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <timer.h>
#include <asm/io.h>
#define MCHP_PIT64B_CR 0x00 /* Control Register */
#define MCHP_PIT64B_CR_START BIT(0)
#define MCHP_PIT64B_CR_SWRST BIT(8)
#define MCHP_PIT64B_MR 0x04 /* Mode Register */
#define MCHP_PIT64B_MR_CONT BIT(0)
#define MCHP_PIT64B_LSB_PR 0x08 /* LSB Period Register */
#define MCHP_PIT64B_MSB_PR 0x0C /* MSB Period Register */
#define MCHP_PIT64B_TLSBR 0x20 /* Timer LSB Register */
#define MCHP_PIT64B_TMSBR 0x24 /* Timer MSB Register */
struct mchp_pit64b_priv {
void __iomem *base;
};
static int mchp_pit64b_get_count(struct udevice *dev, u64 *count)
{
struct mchp_pit64b_priv *priv = dev_get_priv(dev);
u32 lsb = readl(priv->base + MCHP_PIT64B_TLSBR);
u32 msb = readl(priv->base + MCHP_PIT64B_TMSBR);
*count = ((u64)msb << 32) | lsb;
return 0;
}
static int mchp_pit64b_probe(struct udevice *dev)
{
struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
struct mchp_pit64b_priv *priv = dev_get_priv(dev);
struct clk clk;
ulong rate;
int ret;
priv->base = dev_read_addr_ptr(dev);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return ret;
ret = clk_enable(&clk);
if (ret)
return ret;
rate = clk_get_rate(&clk);
if (!rate) {
clk_disable(&clk);
return -ENOTSUPP;
}
/* Reset the timer in case it was used by previous bootloaders. */
writel(MCHP_PIT64B_CR_SWRST, priv->base + MCHP_PIT64B_CR);
/*
* Use highest prescaller (for a peripheral clock running at 200MHz
* this will lead to the timer running at 12.5MHz) and continuous mode.
*/
writel((15 << 8) | MCHP_PIT64B_MR_CONT, priv->base + MCHP_PIT64B_MR);
uc_priv->clock_rate = rate / 16;
/*
* Simulate free running counter by setting max values to period
* registers.
*/
writel(~0UL, priv->base + MCHP_PIT64B_MSB_PR);
writel(~0UL, priv->base + MCHP_PIT64B_LSB_PR);
/* Start the timer. */
writel(MCHP_PIT64B_CR_START, priv->base + MCHP_PIT64B_CR);
return 0;
}
static const struct timer_ops mchp_pit64b_ops = {
.get_count = mchp_pit64b_get_count,
};
static const struct udevice_id mchp_pit64b_ids[] = {
{ .compatible = "microchip,sam9x60-pit64b", },
{ .compatible = "microchip,sama7g5-pit64b", },
{ }
};
U_BOOT_DRIVER(mchp_pit64b) = {
.name = "mchp-pit64b",
.id = UCLASS_TIMER,
.of_match = mchp_pit64b_ids,
.priv_auto_alloc_size = sizeof(struct mchp_pit64b_priv),
.probe = mchp_pit64b_probe,
.ops = &mchp_pit64b_ops,
.flags = DM_FLAG_PRE_RELOC,
};
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